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Sample records for citri mcgregor acari

  1. Involvement of Three Esterase Genes from Panonychus citri (McGregor in Fenpropathrin Resistance

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    Xiao-Min Shen

    2016-08-01

    Full Text Available The citrus red mite, Panonychus citri (McGregor, is a major citrus pest with a worldwide distribution and an extensive record of pesticide resistance. However, the underlying molecular mechanism associated with fenpropathrin resistance in this species have not yet been reported. In this study, synergist triphenyl phosphate (TPP dramatically increased the toxicity of fenpropathrin, suggesting involvement of carboxylesterases (CarEs in the metabolic detoxification of this insecticide. The subsequent spatiotemporal expression pattern analysis of PcE1, PcE7 and PcE9 showed that three CarEs genes were all over-expressed after insecticide exposure and higher transcripts levels were observed in different field resistant strains of P. citri. Heterologous expression combined with 3-(4,5-dimethyl-thiazol-2-yl-2,5-diphenyltetra-zolium bromide (MTT cytotoxicity assay in Spodoptera frugiperda (Sf9 cells revealed that PcE1-, PcE7- or PcE9-expressing cells showed significantly higher cytoprotective capability than parental Sf9 cells against fenpropathrin, demonstrating that PcEs probably detoxify fenpropathrin. Moreover, gene silencing through the method of leaf-mediated dsRNA feeding followed by insecticide bioassay increased the mortalities of fenpropathrin-treated mites by 31% (PcE1, 27% (PcE7 and 22% (PcE9, respectively, after individual PcE gene dsRNA treatment. In conclusion, this study provides evidence that PcE1, PcE7 and PcE9 are functional genes mediated in fenpropathrin resistance in P. citri and enrich molecular understanding of CarEs during the resistance development of the mite.

  2. Primeiro registro de Oligonychus yothersi (McGregor (Acari: Tetranychidae em Eucalyptus grandis Hill ex Maiden no Brasil First record of Oligonychus yothersi (McGregor (Acari: Tetranychidae on Eucalyptus grandis Hill ex Maiden in Brazil

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    Fabrício Fagundes Pereira

    2005-08-01

    Full Text Available Relata-se a infestação de um ácaro-vermelho em mudas clonais de Eucalyptus grandis Hill ex Maiden, mantidas em casa de vegetação no município de Martinho Campos, Minas Gerais. O ácaro foi observado na parte superior das folhas que exibiam sinais de sucção de seiva e bronzeamento. Essas injúrias causaram desenvolvimento anormal e morte de plantas. O ácaro foi identificado como Oligonychus yothersi (McGregor (Acari: Tetranychidae, e isso representa o primeiro registro dessa espécie em mudas clonais de E. grandis no Brasil.An infestation of the red spider mite was reported in clone seedlings of Eucalyptus grandis Hill ex Maiden under greenhouse conditions, in the municipality of Martinho Campos, Minas Gerais State. The spider mite was found on the leaf upper faces with signs of sap suction and bronzing. Such injuries caused abnormal development and plant death. The spider mite was identified as Oligonychus yothersi (McGregor (Acari: Tetranychidae. This is the first record of O. yothersi on E. grandis seedlings in Brazil.

  3. Influence of the webbing produced by Oligonychus ilicis (McGregor) (Acari: Tetranychidae) on associated predatory phytoseiids; Influencia da teia de Oligonychus ilicis (McGregor) (Acari: Tetranychidae) sobre os fitoseideos predadores associados

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    Franco, Renato A. [Bioagri Laboratorios Ltda., Piracicaba, SP (Brazil)], e-mail: r.franco@bioagri.com.br; Reis, Paulo R. [Empresa de Pesquisa Agropecuaria de Minas Gerais (EPAMIG), Belo Horizonte, MG (Brazil). Ecocentro], e-mail: paulo.rebelles@epamig.ufla.br; Zacarias, Mauricio S. [EMBRAPA Cafe, Lavras, MG (Brazil)], e-mail: zacarias@epamig.ufla.br; Oliveira, Daniel C. [Universidade Federal de Lavras (UFLA), MG (Brazil)

    2010-01-15

    Oligonychus ilicis (McGregor) is among those mite species that can cause damage to coffee plants (Coffea spp.). Species of Phytoseiidae acari are considered the most important and studied predatory mites. The objective of this study was to evaluate the effects of the webbing produced by O. ilicis on its predation by females of the phytoseiids Iphiseiodes zuluagai Denmark and Muma, Euseius citrifolius Denmark and Muma and Amblyseius herbicolus (Chant). Four bioassays were conducted, with three treatments and ten replicates. Each replicate consisted of 25 O. ilicis per experimental unit (a leaf disc of Coffea arabica) according to the tested developmental stage, in independent experiments. To spin the web, 15 adult females were put on each experimental unit for 24h; females were then removed, leaving only the web, and predators and prey to be tested were introduced. Predation was assessed after 24h. In the presence of webbing, the consumption of eggs, larvae and nymphs by I. zuluagai and eggs and larvae by E. citrifolius was lower. For A. herbicolus, egg predation was lower, but larval predation did not vary significantly and predation of nymphs and adults was higher in the presence of webbing. Predators as a whole were more efficient consuming larvae regardless of the presence of webbing. Considering the stages of O. ilicis altogether, webbing reduced the predation potential of I. zuluagai and E. citrifolius, but not of A. herbicolus. (author)

  4. Influence of the webbing produced by Oligonychus ilicis (McGregor) (Acari: Tetranychidae) on associated predatory phytoseiids

    International Nuclear Information System (INIS)

    Franco, Renato A.; Reis, Paulo R.; Oliveira, Daniel C.

    2010-01-01

    Oligonychus ilicis (McGregor) is among those mite species that can cause damage to coffee plants (Coffea spp.). Species of Phytoseiidae acari are considered the most important and studied predatory mites. The objective of this study was to evaluate the effects of the webbing produced by O. ilicis on its predation by females of the phytoseiids Iphiseiodes zuluagai Denmark and Muma, Euseius citrifolius Denmark and Muma and Amblyseius herbicolus (Chant). Four bioassays were conducted, with three treatments and ten replicates. Each replicate consisted of 25 O. ilicis per experimental unit (a leaf disc of Coffea arabica) according to the tested developmental stage, in independent experiments. To spin the web, 15 adult females were put on each experimental unit for 24h; females were then removed, leaving only the web, and predators and prey to be tested were introduced. Predation was assessed after 24h. In the presence of webbing, the consumption of eggs, larvae and nymphs by I. zuluagai and eggs and larvae by E. citrifolius was lower. For A. herbicolus, egg predation was lower, but larval predation did not vary significantly and predation of nymphs and adults was higher in the presence of webbing. Predators as a whole were more efficient consuming larvae regardless of the presence of webbing. Considering the stages of O. ilicis altogether, webbing reduced the predation potential of I. zuluagai and E. citrifolius, but not of A. herbicolus. (author)

  5. SELETIVIDADE DE INSETICIDAS A Neoseiulus californicus MCGREGOR (ACARI: PHYTOSEIIDAE EM MACIEIRA, NO RIO GRANDE DO SUL AGROCHEMICAL SELECTIVITY TO Neoseiulus californicus MCGREGOR (ACARI: PHYTOSEIIDAE ON APPLE IN RIO GRANDE DO SUL

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    LINO BITTENCOURT MONTEIRO

    2001-12-01

    Full Text Available Testes para determinar os efeitos de agroquímicos homologados para macieira foram realizados em laboratório sobre Neoseiulus californicus (Acari: Phytoseiidae. Os indivíduos testados foram coletados de um pomar comercial da Agriflor Ltda, em Vacaria, Rio Grande do Sul, após várias liberações inoculativas. Os inseticidas utilizados foram os tradicionalmente recomendados para o controle de pragas, principalmente mosca-das-frutas Anastrepha fraterculus (Diptera: Tephritidae. A oviposição e a mortalidade dos ácaros foram avaliadas 12; 24; 48 e 96 horas após a pulverização, cujos produtos foram classificados em quatro classes de toxicidade (IOBC/WPRS. Azinphos ethyl, deltametrina e fenthion provocaram 100% de mortalidade, sendo que dimethoate, fenitrotion, paration, phosmet e triclorfon foram levemente nocivos (classe 2. Malation foi considerado neutro para esta população.The side-effects of agrochemical to Neoseiulus californicus (Acari: Phytoseiidae were studied in laboratory. The mites were collected in commercial apple orchard of Agropastoril Rincão das Flores, in Vacaria, Rio Grande do Sul, Brazil, after successive inoculative releases. The insecticids used were recommended to control of same pest, as Anastrepha fraterculus (Diptera: Tephritidae. The reproduction effect and mortality were evalued 12, 24, 48 and 96 hours after pulverization, while the agrochemical were ranked in toxicity classes, according to IOBC/WPRS. Azinphos ethyl, deltametrina e fenthion were harmful with ca. 100% of mortality in 24 hours, dimethoate, fenitrotion, paration, phosmet e triclorfon were slightly harmful (class 2. Malation was harmless.

  6. Toxicidade residual de alguns agrotóxicos recomendado na agricultura sobre Neoseiulus californicus (McGregor (Acari: Phytoseiidae Residual toxicity of some pesticides recommended for citrus orchards on the predaceous mite Neoseiulus californicus (McGregor (Acari: phytoseiidae

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    Marcos Zatti da Silva

    2007-04-01

    Full Text Available O objetivo do trabalho foi avaliar a toxicidade residual de alguns agrotóxicos utilizados em citros sobre Neoseiulus californicus (McGregor em condições de laboratório. O método de bioensaio adotado foi o de contato residual. Folhas de citros da variedade Pêra, acondicionadas em arenas, foram pulverizadas em torre de Potter. A toxicidade residual dos produtos foi avaliada duas horas e 1; 3; 5; 7; 10; 14 e 21 dias após a aplicação. Em cada arena, foram transferidas dez fêmeas adultas de N. californicus, juntamente com uma quantidade suficiente de Tetranychus urticae, como fonte de alimento. As avaliações de mortalidade foram realizadas 72 horas após a transferência dos ácaros para as arenas. Os agrotóxicos acrinathrin, deltamethrin, dinocap, enxofre, fenpropathrin, óxido de fenbutatin e propargite não causaram mortalidades significativas em adultos de N. californicus. Foram registradas mortalidades de 29,8; 24,0 e 34,1% para ácaros N. californicus expostos a resíduos de duas horas de idade de abamectim, azocyclotin e cyhexatin, respectivamente. Dicofol, pyridaben e chlorfenapyr causaram 100% de mortalidade aos ácaros predadores expostos aos resíduos tóxicos dos acaricidas, com duas horas de idade. Abamectin provocou mortalidade significativa por um período inferior a um dia. Resíduos dos acaricidas azocyclotin, cyhexatin, dicofol, pyridaben e chlorfenapyr provocaram mortalidades significativas por períodos de 1; 1; 10; 10 e 21dias, respectivamente. Os resultados obtidos no presente experimento servem de subsídio para a escolha adequada dos agrotóxicos a serem utilizados em pomares de citros nos quais N. californicus esteja presente ou naqueles em que o predador venha a ser liberado. Esses resultados também servem para a escolha do momento mais favorável para a liberação dos ácaros predadores dessa espécie no campo, após a aplicação de agrotóxicos nos pomares. Estudos conduzidos em condições de campo ainda s

  7. Molecular Effects of Irradiation (Cobalt-60 on the Control of Panonychus citri (Acari: Tetranychidae

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    Ke Zhang

    2015-11-01

    Full Text Available The effective dose of irradiation to control pest mites in quarantine has been studied extensively, but the molecular mechanisms underlying the effects of the irradiation on mites are largely unknown. In this study, exposure to 400 Gy of γ rays had significant (p < 0.05 effects on the adult survival, fecundity and egg viability of Panonychus citri. The irradiation caused the degradation of the DNA of P. citri adults and damaged the plasma membrane system of the egg, which led to condensed nucleoli and gathered yolk. Additionally, the transcriptomes and gene expression profiles between irradiated and non-irradiated mites were compared, and three digital gene expression libraries were assembled and analyzed. The differentially expressed genes were putatively involved in apoptosis, cell death and the cell cycle. Finally, the expression profiles of some related genes were studied using quantitative real-time PCR. Our study provides valuable information on the changes in the transcriptome of irradiated P. citri, which will facilitate a better understanding of the molecular mechanisms that cause the sterility induced by irradiation.

  8. Life history of Neoseiulus californicus (McGregor, 1954 (Acari: Phytoseiidae fed with castor bean (Ricinus communisL. pollen in laboratory conditions

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    PP Marafeli

    Full Text Available The predatory mite, Neoseiulus californicus(McGregor, 1954 (Acari: Phytoseiidae is one of the principal natural enemies of tetranychid mites in several countries, promoting efficient control of those mites in several food and ornamental crops. Pest attacks such as that of the spider mite, Tetranychus urticaeKoch, 1836 (Acari: Tetranychidae, is one of the problems faced by farmers, especially in the greenhouse, due to the difficulty of its control with the use of chemicals because of the development of fast resistance making it hard to control it. The objective of this work was to study the life history of the predatory mite N. californicus as a contribution to its mass laboratory rearing, having castor bean plant [Ricinus communis L. (Euphorbiaceae] pollen as food, for its subsequent use as a natural enemy of T. urticae on a cultivation of greenhouse rosebushes. The studies were carried out in the laboratory, at 25 ± 2°C of temperature, 70 ± 10% RH and a 14 hour photophase. The biological aspects and the fertility life table were appraised. Longevity of 32.9 days was verified for adult females and 40.4 days for males. The intrinsic rate of increase (rm was 0.2 and the mean generation time (T was 17.2 days. The population doubled every 4.1 days. The results obtained were similar to those in which the predatory mite N. californicus fed on T. urticae.

  9. Side Effects of Four Acaricides on the Predatory Mites of Neoseiulus californicus McGregor and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae

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    Sibel YORULMAZ SALMAN

    2017-01-01

    Full Text Available In the present study determined the side effects of four acaricides of acequinocyl, etoxazole, bifenazate and milbemectin on the predator mites Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus McGregor. Acaricide concentrations were prepared as a two times the field application dose (2T, field application dose (T, and half of the field application dose (T/2 and were then applied on eggs, nymphs and adults of the P. persimilis and N. californicus. The side effects of the acaricidesapplied to the predator mites were determined three, five and seven days afterthe application. While all doses of acequinocyl and etoxazole showed a higher toxic effect on N.californicus eggs, it was found that bifenazate and milbemectin caused similar effects on both predator mite eggs. Furthermore, it was found that the toxic effects of acequinocyl, etoxazole, bifenazate and milbemectin on nymphs and adults of the predator miteswere high seventh day after the application. The results of the study showed that four acaracides frequently used against to pest mites, should be used more carefully in the agricultural areas.

  10. Non-preference of the red mite Oligonychus yothersi McGregor (Acari: Tetranychidae for oviposition on leaves of Paraguay tea progenies (Ilex paraguariensis/ Não-preferência do ácaro-vermelho, Oligonychus yothersi McGregor (Acari: Tetranychidae, para oviposição em folhas de progênies de erva-mate (Ilex paraguariensis

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    José Djair Vendramim

    2007-10-01

    Full Text Available The oviposition preference of the red mite Oligonychus yothersi McGregor was evaluated under laboratory in 52 Paraguay tea progenies and one control collected in a local farm. The experiments were conducted on Paraguay tea leaf discs infested with one adult female mite/disc, incubated in a climate chamber (25±1ºC, 14h photophase for five days. Evaluations were performed daily, by counting the number of eggs laid in the period, the number of female escapes in the first 48 hours, as well as the number of eggs laid before the escaping. It was verified that discrimination by the mite occurred on two groups of progenies, in relation to the number of eggs: one group was different from the control (53.8% of the progenies and the other was identical to it (46.2% of the progenies. In the first group, 60.7% of progenies were less oviposited while a higher number of eggs/female than the control was verified in 39.3% of them. In 57.7% of progenies there was escape of some mites (10 to 40%, and in 10 of these progenies no eggs were laid. The data provide evidences that in some of the progenies evaluated there is resistance by non-preference to oviposition of the Paraguay tea red mite.A preferência para oviposição do ácaro-vermelho, Oligonychus yothersi McGregor, foi avaliada em condições de laboratório em 52 progênies de erva-mate e uma testemunha coletada em uma propriedade da região. Os experimentos foram realizados em discos foliares de erva-mate (2 cm de diâmetro, infestados com uma fêmea adulta do ácaro, e incubados a 25±1ºC e 14h de fotofase, durante cinco dias. As avaliações foram realizadas diariamente, contando-se o número de ovos depositados no período, número de fêmeas que fugiram nas primeiras 48 horas e número de ovos depositados antes da fuga. Verificou-se que houve discriminação do ácaro em dois grupos de progênies, em relação ao número de ovos, um que diferiu em relação à testemunha (53,8% de progênies e

  11. Controle de Brevipalpus phoenicis (Geijskes, 1939 e Oligonychus ilicis (McGregor, 1917 (Acari: Tenuipalpidae, Tetranychidae em cafeeiro e o impacto sobre ácaros benéficos: II - Spirodiclofen e Azocyclotin Control of Brevipalpus phoenicis (Geijskes, 1939 and Oligonychus ilicis (McGregor, 1917 (Acari: Tenuipalpidae, Tetranychidae in coffee plants and the impact on beneficial mites: II - Spirodiclofen and Azocyclotin

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    Paulo Rebelles Reis

    2005-06-01

    Full Text Available O ácaro Brevipalpus phoenicis (Geijskes é importante em cafeeiro (Coffea spp. por ser o vetor do vírus da mancha-anular, doença responsável por queda de folhas e má qualidade da bebida do café, e o ácaro-vermelho Oligonychus ilicis (McGregor por reduzir a área foliar de fotossíntese. Ácaros da família Phytoseiidae, de várias espécies, são eficientes predadores associados aos ácaros-praga. Conduziu-se este trabalho com o objetivo de estudar o controle dos ácaros-praga com spirodiclofen e azocyclotin, e o impacto sobre fitoseídeos. Em laboratório foram estudados os efeitos ovicida, tópico, residual, tópico mais residual e a seletividade fisiológica aos fitoseídeos; em casa-de-vegetação foi avaliada a persistência no controle às duas espécies de ácaros-praga; e em campo foi avaliada a eficiência apenas no controle de B. phoenicis. Os bioensaios foram realizados em arenas de folhas destacadas. O efeito ovicida foi avaliado em ovos no início e final de incubação. Os efeitos residual, tópico e tópico mais residual foram avaliados pela mortalidade de larvas, ninfas e adultos aos oito dias, e a persistência até 30 dias após a aplicação. A seletividade aos fitoseídeos foi avaliada, pelo efeito na mortalidade e reprodução de fêmeas adultas, em teste residual em superfície de vidro. Spirodiclofen e azocyclotin (SC mostraram eficiente ação ovicida, principalmente para ovos de B. phoenicis no início de incubação. Para ovos de O. ilicis, somente o spirodiclofen apresentou efeito ovicida. Em geral, os efeitos tópico e residual associados melhoraram a eficiência dos produtos no controle das fases pós-embrionárias de ambas as espécies. O spirodiclofen apresentou seletividade aos ácaros predadores, já o azocyclotin foi nocivo. Em campo, ambos os acaricidas mostram-se altamente eficientes na redução de todas as fases pós-embrionárias do ácaro B. phoenicis, principalmente nas folhas.The mite Brevipalpus

  12. Analysis of transcriptome differences between resistant and susceptible strains of the citrus red mite Panonychus citri (Acari: Tetranychidae.

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    Bin Liu

    Full Text Available BACKGROUND: The citrus red mite is a worldwide citrus pest and a common sensitizing allergen of asthma and rhinitis. It has developed strong resistance to many registered acaricides, However, the molecular mechanisms of resistance remain unknown. we therefore used next generation sequencing technology to investigate the global transcriptomes between resistant strains and susceptible strains. RESULTS: We obtained 34,159, 30,466 and 32,217 unigenes by assembling the SS reads, RS reads and SS&RS reads respectively. There are total 17,581 annotated unigenes from SS&RS reads by BLAST searching databases of nr, the Clusters of Orthologous Groups (COGs and Kyoto Encyclopedia of Genes and Genomes (KEGG with an E-value ≤ 1e-5, in which 7,075 unigenes were annotated in the COG database, 12, 712 unigenes were found in the KEGG database and 3,812 unigenes were assigned to Gene ontology (GO. Moreover, 2,701 unigenes were judged to be the differentially expressed genes (DEGs based on the uniquely mapped reads. There are 219 pathways in all annotated unigenes and 198 pathways in DEGs that mapped to the KEGG database. We identified 211 metabolism genes and target genes related to general insecticide resistance such as P450 and Cytochrome b, and further compared their differences between RS and SS. Meanwhile, we identified 105 and 194 genes related to growth and reproduction, respectively, based on the mode of action of Hexythiazox. After further analyses, we found variation in sequences but not in gene expression related to mite growth and reproduction between different strains. CONCLUSION: To our knowledge, this is the first comparative transcriptome study to discover candidate genes involved in phytophagous mite resistance. This study identified differential unigenes related to general pesticide resistance and organism growth and reproduction in P. citri. The assembled, annotated transcriptomes provide a valuable genomic resource for further understanding

  13. Life Table Parameters and Consumption Rate of Cydnodromus picanus Ragusa, Amblyseius graminis Chant, and Galendromus occidentalis (Nesbitt on Avocado Red Mite Oligonychus yothersi (McGregor (Acari: Phytoseiidae, Tetranychidae Parámetros de Tabla de Vida y Tasa de Consumo de Cydnodromus picanus Ragusa, Amblyseius graminis Chant y Galendromus occidentalis (Nesbitt, sobre la Arañita Roja del Palto Oligonychus yothersi (McGregor (Acari: Phytoseiidae, Tetranychidae

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    Tommy Rioja S

    2009-06-01

    Full Text Available The avocado red mite Oligonychus yothersi (McGregor is the major leaf pest in Chile’s avocado orchards. Itaffects leaf physiology and makes it necessary to seek new natural enemies to interact with low population densities of O. yothersi. The potentiality of three predator mites: Cydnodromus picanus Ragusa, Amblyseius graminis Chant, and Galendromus occidentalis (Nesbitt was evaluated under laboratory conditions (27 ± 1.93ºC, 87 ± 3.61% H.R. and 16:8 (L:D photoperiod on avocado leaf disks Persea americana Mill. var. Hass (Ø = 5 cm by separately feeding eggs, immature, and adult females of O. yothersi, and registering postembryonic development, consumption, as well as life table parameters. The postembryonic development of C. picanus was significantly lower (5.46 days compared to both A. graminis (7.33 days and G. occidentalis (8.69 days which were fed with immature O. yothersi. The life table parameters of C. picanus were net reproductive rate R0 = 25.41, finite rate of increase λ = 1.29, and Mean Generation Time T = 12.46. The Net Intrinsic Rate of Increase (r m was significantly higher for C. picanus (r m = 0.25 in contrast with G. occidentalis (r m = 0.19, while A. graminis showed r m = -0.06 indicating that its population didn’t have descendants. Under laboratory conditions, r m registered by C. picanus is an indicator of its predatory potential to control O. Yothersi. It can be assumed that the pest population reduction pattern could be maintained under field conditions.En Chile la arañita roja del palto Oligonychus yothersi (McGregor es la plaga más importante a nivel foliar en huertos comerciales afectando la fisiología de la hoja, siendo necesario la búsqueda de nuevos enemigos naturales que interactúen a bajas densidades poblacionales de O. yothersi. Se evaluó en condiciones de laboratorio (27±1,93ºC, 87±3,61 % H.R. y un fotoperíodo de 16:8 (L:O sobre discos de hojas de palto Persea americana Mill. var. Hass (Ø = 5

  14. Biological control of Eotetranychus lewisi and Tetranychus urticae (Acari: Tetranychidae) on strawberry by four phytoseiids (Acari: Phytoseiidae).

    Science.gov (United States)

    Howell, Anna D; Daugovish, Oleg

    2013-02-01

    The spider mite, Eotetranychus lewisi (McGregor) (Acari: Tetranychidae), is a new emerging pest in California commercial strawberries. The predatory mite Phytoseiulus persimilis (Athias-Henriot) (Acari: Phytoseiidae), typically used for biocontrol of Tetranychus urticae (Koch) (Acari: Tetranychidae), provided growers little to no control of E. lewisi. Four commonly used phytoseiid predatory mites: P. persimilis, Neoseiulus californicus (McGregor), N. fallacis (Garman), and Amblyseius andersoni (Chant), were used in lab studies to investigate which is best at managing E. lewisi populations. We als o investigated t he interactions between T. urticae and E. lewisi and in relation to phytoseiid efficiency given the potential for indirect effects of biocontrol. When E. lewisi and T. urticae are present on the same leaf, T. urticae populations increase and begin displacing E. lewisi. P. persimilis did not feed on E. lewisi, but the other three predatory mites consumed the spider mites and lowered their populations. When both E. lewisi and T. urticae are present on the same leaf, N. fallacis and A. andersoni fed on both types of mites equally and were capable of decreasing both populations. N. californicus fed on E. lewisi first and decreased its population, but allowed T. urticae populations to increase. P. persimilis may be insufficient at controlling E. lewisi and its use may instead enhance E. lewisi populations.

  15. EVALUATING CHAMBERLAIN'S, McGREGOR'S, AND McRAE'S ...

    African Journals Online (AJOL)

    2012-08-08

    Aug 8, 2012 ... spine and base of skull radiographs which however have diagnostic challenges due to the complexity of the ... McGregor's and Mc Rae's using CT bone windows ... metastatic lesion were excluded from the study. RESULTS.

  16. Xanthomonas citri pv. citri pathotypes

    DEFF Research Database (Denmark)

    Di Lorenzo, Flaviana; Silipo, Alba; Gersby, Lotte Bettina Andersen

    2017-01-01

    Xanthomonas citri pv. citri is the pathogen responsible for Asiatic citrus canker, one of the most serious citrus diseases worldwide. The lipopolysaccharide (LPS) molecule has been demonstrated to be involved in X. citri pv. citri virulence. Despite enormous progress in investigations of the mole...

  17. Impact of Mcgregor's X and Y Motivation Theory on the Job ...

    African Journals Online (AJOL)

    This study investigated the impact of McGregor's X and Y motivation theory in the job performance of staff in Ebonyi State University, Abakaliki. The design was a descriptive survey. The population was 2632 and a sample of 100 was randomly selected. Two research questions were formulated to guide the study.

  18. BIOLOGÍA DE OLIGONYCHUS YOTHERSI (MCGREGOR (ACARI: TETRANYCHIDAE SOBRE AGUACATE PERSEA AMERICANA MILL. CV. LORENA (LAURACEAE

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    Reyes Julian C

    2011-06-01

    Full Text Available Se estudió la biología del ácaro rojo Oligonychus yothersi en condiciones controladas(26 ± 3°C 56 ± 3% HR, sobre hojas maduras de aguacate, Persea americana Mill. cv.Lorena. Las observaciones se realizaron durante una generación del ácaro. La duraciónde todos los estados, a excepción del adulto, fueron los siguientes: huevo 119.06 horas±13.77 (4.96 días; larva 54.09 horas ± 18.48 (2.25 días, protocrisálida 18.22 ± 9.53(0.76 días, protoninfa 50.62 horas ± 13.29 (2.11 días, deutocrisalida 21.66 horas ±7.78 (0.90 días, deutoninfa 62.54 horas ± 12.85 (2.61 días y teliocrisalida 30.79 horas± 13.28 (1.28 días. La duración total de huevo a emergencia de adulto fue estimadaen 344.21 horas (14.34 días. La relación de sexos encontrada fue de 4.8 hembras: 1macho. Los parámetros poblacionales, i.e., longevidad, fecundidad, tasa intrínsecade crecimiento (r m , tiempo de duplicación y tiempo generacional, sugieren un altopotencial reproductivo y de desarrollo del ácaro sobre aguacate cv. Lorena.

  19. Impact of sulfur on density of Tetranychus pacificus (Acari: Tetranychidae) and Galendromus occidentalis (Acari: Phytoseiidae) in a central California vineyard.

    Science.gov (United States)

    Costello, Michael J

    2007-01-01

    Sulfur is the oldest and most widely used fungicide in the vineyards of California, where it is used for control of powdery mildew (Uncinula necator [Schw.] Burr). For decades, sulfur use has been associated with outbreaks of Tetranychus pacificus McGregor (Acari: Tetranychidae) on cultivated grapes in the San Joaquin Valley. I undertook large-scale field studies to test this association, to evaluate the impact of sulfur on Galendromus occidentalis (Nesbit) (Acari: Phytoseiidae), a major predator of T. pacificus, and to determine if timing of sulfur applications with respect to grape bloom has an impact on T. pacificus density. The studies took place in a 32 ha vineyard in Fresno County, and all fungicide applications were made with commercial-scale equipment. In 1998 a 'high sulfur' treatment, a combination of wettable sulfur and sulfur dust, was compared to 'low sulfur,' in which demethylation inhibitor (DMI) fungicides partially substituted for sulfur. In 1999 treatments were 'sulfur,' 'DMI,' 'sulfur pre-bloom' (here sulfur was applied prior to grape bloom, in late May, and then DMIs were applied until mid-season) and 'sulfur post-bloom' (the reverse of 'sulfur pre-bloom'). In each year, the T. pacificus population increase came after the end of fungicide applications, and results clearly show a relationship between sulfur use and T. pacificus density. In 1998, mean T. pacificus density was 2.7 times higher and mean G. occidentalis density 2.5 times higher in 'high sulfur' compared to 'low sulfur.' In 1999, the highest T. pacificus counts were in the 'sulfur' and 'sulfur pre-bloom' treatments, 4.8 times higher than 'sulfur post-bloom' and 2 times higher than 'DMIs.' Density of G. occidentalis was 2.3 times as high in 'sulfur' or 'sulfur pre-bloom' than 'DMIs.' The predator/prey ratio was not significantly different among treatments in 1998, but in 1999 it was highest in the 'sulfur pre-bloom' treatment. In 1999, density of Homeopronematus anconai (Baker) (Acari

  20. Efeitos do nim sobre tetranychus urticae Koch (Acari: Tetranychidae e os predadores Phytoseiulus macropilis (Banks e Neoseiulus californicus (Mcgregor (Acari: Phytoseiidae

    Directory of Open Access Journals (Sweden)

    Daniele Cristine Hoffmann Schlesener

    2013-03-01

    Full Text Available O objetivo deste trabalho foi avaliar a eficiência de controle e os efeitos adversos de dois produtos à base de nim Azamax® (Azadiractina A/B 12g/L e Neemseto® (Azadiractina A/B, Nimbina e Salanina 2,389 g/L sobre o ácaro-rajado Tetranychus urticae e os predadores Phytoseiulus macropilis e Neoseiulus californicus em laboratório. Para o ácaro-rajado, foram consideradas as variáveis mortalidade, fecundidade, efeito ovicida e persistência biológica, enquanto para os fitoseídeos consideraram-se mortalidade e fecundidade. A mortalidade máxima observada para o ácaro-rajado foi de 89,7% e 91,5% para Azamax® e Neemseto®, respectivamente, na concentração de 0,5% após a reaplicação do produto no sétimo dia. Também foram observados efeitos adversos sobre a fecundidade e a viabilidade dos ovos quando tratados com os produtos comerciais (p.c.. A persistência biológica dos produtos foi de aproximadamente três dias após a pulverização. As formulações apresentaram seletividade em relação aos fitoseídeos, porém causaram redução da fecundidade dos mesmos.

  1. Resistance of sweet orange Pera (Citrus sinensis) genotypes to Xanthomonas citri subsp. citri under field conditions

    Science.gov (United States)

    Citrus canker control is based on protection measures and eradication of plants infected with Xanthomonas citri subsp. citri. Although these measures show satisfactory results, the use of resistant genotypes is an important alternative for citrus canker control. The aim of this study was to evaluate...

  2. Record of Diaphorina citri (Hemiptera: Psyllidae) in North West Argentina

    OpenAIRE

    Augier, Lucrecia; Gastaminza, Gerardo; Lizondo, Marcelo; Argañaraz, Manuel; Willink, Eduardo

    2006-01-01

    Se amplía la distribución de Diaphorina citri Kuwayama (Hemiptera: Psyllidae) para el Noroeste Argentino.The distribution of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is expanded to North West Argentina.

  3. The residual and direct effects of reduced-risk and conventional miticides on twospotted spider mites, Tetranychus urticae (Acari: Tetranychidae) and predatory mites (Acari: Phytoseiidae)

    International Nuclear Information System (INIS)

    Liburd, O.E.; White, J.C.; Rhodes, E.M.; Browdy, A.A.

    2007-01-01

    The residual effects of several reduced-risk and conventional miticides were evaluated in strawberries (Fragaria × ananassa Duchesne) on the twospotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae) and on 2 predatory mites, Neoseiulus californicus McGregor and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae). Experiments were conducted in the laboratory and greenhouse. The greenhouse experiments also tested the direct effects of the miticides on TSSM. The efficacy of conventional and reduced-risk miticides was evaluated on strawberry leaf discs and on whole plants for control of TSSM. Furthermore, the residual effects of these miticides were evaluated on whole strawberry plants against selective predatory mites. For TSSM, 5 treatments were evaluated: a conventional miticide; fenbutatin-oxide (Vendex[reg]) and 3 reduced-risk miticides; binfenazate (Acramite 50WP[reg]), activated garlic extract (Repel[reg]), sesame seed and castor oil (Wipeout[reg]), and a water-treated control. For predatory mites, the residual effects of only Acramite[reg] and Vendex[reg] were evaluated. Acramite[reg] was the most effective acaricide in reducing TSSM populations in both the laboratory and greenhouse experiments. Vendex[reg] and Wipeout[reg] were also effective in the laboratory, but did not cause significant reduction of TSSM in the greenhouse. Repel[reg] was the least effective of the 4 pesticides evaluated. Neither Acramite[reg] nor Vendex[reg] had a significant effect on either predatory mite species. However, there appeared to be more predatory mites on the Vendex[reg]-treated plants than on the Acramite[reg]-treated plants. There were significantly more predatory mites of both species on the cue plants, which were inoculated with TSSM versus the non-cue plants, which were not inoculated. (author) [es

  4. Efeitos do nim sobre tetranychus urticae Koch (Acari: Tetranychidae e os predadores Phytoseiulus macropilis (Banks e Neoseiulus californicus (Mcgregor (Acari: Phytoseiidae Effects of neem on tetranychus urticae Koch (Acari: Tetranychidae and the predators Phytoseiulus macropilis (Banks and Neoseiulus Californicus (Mcgregor (Acari: phytoseiidae

    Directory of Open Access Journals (Sweden)

    Daniele Cristine Hoffmann Schlesener

    2013-03-01

    Full Text Available O objetivo deste trabalho foi avaliar a eficiência de controle e os efeitos adversos de dois produtos à base de nim Azamax® (Azadiractina A/B 12g/L e Neemseto® (Azadiractina A/B, Nimbina e Salanina 2,389 g/L sobre o ácaro-rajado Tetranychus urticae e os predadores Phytoseiulus macropilis e Neoseiulus californicus em laboratório. Para o ácaro-rajado, foram consideradas as variáveis mortalidade, fecundidade, efeito ovicida e persistência biológica, enquanto para os fitoseídeos consideraram-se mortalidade e fecundidade. A mortalidade máxima observada para o ácaro-rajado foi de 89,7% e 91,5% para Azamax® e Neemseto®, respectivamente, na concentração de 0,5% após a reaplicação do produto no sétimo dia. Também foram observados efeitos adversos sobre a fecundidade e a viabilidade dos ovos quando tratados com os produtos comerciais (p.c.. A persistência biológica dos produtos foi de aproximadamente três dias após a pulverização. As formulações apresentaram seletividade em relação aos fitoseídeos, porém causaram redução da fecundidade dos mesmos.The aim of the present study was to evaluate the efficiency of control and adverse effects of two neem based products: Azamax TM (Azadirachtin A/B 12g/L and Neemseto TM (Azadirachtin A/B, Nimbin and Salanin 2,389 g/L over two-spotted spider mite Tetranychus urticae and the predators Phytoseiulus macropilis and Neoseiulus californicus in laboratory. Effects over the mortality, fecundity, eggs and biological persistence of the two-spotted spider mite when treated with neem based products were evaluated. For the phytoseiids the effects on mortality and fecundity were evaluated. The maximum mortality of two-spotted spider mites rates observed were 89.7% and 91.5% for Azamax TM and Neemseto TM respectively, on the 0.5% concentration after reapplying the product on the seventh day. Adverse effects were also observed over the fecundity and viability of the eggs when treated with commercial products (c.p.. The biological persistence of the products was of approximately three days after being pulverized. The formulations present selectivity in relation to the phytoseiids, however they caused fecundity reduction.

  5. The type III protein secretion system contributes to Xanthomonas citri subsp. citri biofilm formation

    KAUST Repository

    Zimaro, Tamara

    2014-04-18

    Background: Several bacterial plant pathogens colonize their hosts through the secretion of effector proteins by a Type III protein secretion system (T3SS). The role of T3SS in bacterial pathogenesis is well established but whether this system is involved in multicellular processes, such as bacterial biofilm formation has not been elucidated. Here, the phytopathogen Xanthomonas citri subsp. citri (X. citri) was used as a model to gain further insights about the role of the T3SS in biofilm formation. Results: The capacity of biofilm formation of different X. citri T3SS mutants was compared to the wild type strain and it was observed that this secretion system was necessary for this process. Moreover, the T3SS mutants adhered proficiently to leaf surfaces but were impaired in leaf-associated growth. A proteomic study of biofilm cells showed that the lack of the T3SS causes changes in the expression of proteins involved in metabolic processes, energy generation, exopolysaccharide (EPS) production and bacterial motility as well as outer membrane proteins. Furthermore, EPS production and bacterial motility were also altered in the T3SS mutants. Conclusions: Our results indicate a novel role for T3SS in X. citri in the modulation of biofilm formation. Since this process increases X. citri virulence, this study reveals new functions of T3SS in pathogenesis. 2014 Zimaro et al.; licensee BioMed Central Ltd.

  6. Identification of an Extracellular Endoglucanase That Is Required for Full Virulence in Xanthomonas citri subsp. citri.

    Directory of Open Access Journals (Sweden)

    Tian Xia

    Full Text Available Xanthomonas citri subsp. citri causes citrus canker disease, which is characterized by the formation of water-soaked lesions, white or yellow spongy pustules and brown corky canker. In this work, we report the contribution of extracellular endoglucanase to canker development during infection. The ectopic expression of nine putative cellulases in Escherichia coli indicated that two endoglucanases, BglC3 and EngXCA, show carboxymethyl cellulase activity. Both bglC3 and engXCA genes were transcribed in X. citri subsp. citri, however, only BglC3 protein was detected outside the cell in western blot analysis. The deletion of bglC3 gene resulted in complete loss of extracellular carboxymethyl cellulase activity and delayed the onset of canker symptoms in both infiltration- and wound-inoculation assays. When growing in plant tissue, the cell density of bglC3 mutant was lower than that of the wild type. Our data demonstrated that BglC3 is an extracellular endoglucanase required for the full virulence of X. citri subsp. citri.

  7. The cys regulon of Xanthomonas citri

    Energy Technology Data Exchange (ETDEWEB)

    Moutran, A.; Balan, A. [Laboratorio Nacional de Biociencias - LNBIO, Campinas, SP (Brazil)

    2012-07-01

    Full text: In Escherichia coli, genes involved in metabolic pathway of sulfate and sulfonate compounds are clustered in a cys regulon, which includes three ABC transport system (operons: sbpcysWUA; ssuABC and tauABC), thirteen genes involved in the sulfur reduction (ssuDE; tauD and cysDNCHIJGK) and two regulatory proteins that belong to LysR transcription family: CysB and Cbl. Notably, a search and comparative analysis of these genes in the genomes of the citrus pathogen Xanthomonas citri and other phylogenetically related Xanthomonas species revealed the presence of genes involved with alkanesulfonate, sulfate ester and taurine, only in X. citri, suggesting that proteins from this regulon might be associated with pathogenicity in citrus. Using the molecular modeling associated with a system biology view, we modeled all the protein structures of the X. citri cys regulon as well as characterized the important residues forming the putative active sites. Comparison with orthologs from different microorganisms was made in order to get a phylogenetic relationships. We showed that proteins that are responsible for the affinity and specificity of the alkanesulfonate, sulfate and taurine transport systems conserved the residues involved in the sulfate coordination but are organized in different branches in evolution. Inside these phylogenetic branches, proteins involved in the sulfate transporter are highly conserved when compared to the others. Moreover, we identified that the taurine-binding protein (TauA) of the X. citri belongs to a different evolutionary branch from that one that described for E. coli. These differences were also noticed for components of the tau operon, including a putative new regulator. The function and mechanism of action of each protein is discussed in order to bring light for the sulfur assimilation processes and their importance for X. citri physiology. (author)

  8. The cys regulon of Xanthomonas citri

    International Nuclear Information System (INIS)

    Moutran, A.; Balan, A.

    2012-01-01

    Full text: In Escherichia coli, genes involved in metabolic pathway of sulfate and sulfonate compounds are clustered in a cys regulon, which includes three ABC transport system (operons: sbpcysWUA; ssuABC and tauABC), thirteen genes involved in the sulfur reduction (ssuDE; tauD and cysDNCHIJGK) and two regulatory proteins that belong to LysR transcription family: CysB and Cbl. Notably, a search and comparative analysis of these genes in the genomes of the citrus pathogen Xanthomonas citri and other phylogenetically related Xanthomonas species revealed the presence of genes involved with alkanesulfonate, sulfate ester and taurine, only in X. citri, suggesting that proteins from this regulon might be associated with pathogenicity in citrus. Using the molecular modeling associated with a system biology view, we modeled all the protein structures of the X. citri cys regulon as well as characterized the important residues forming the putative active sites. Comparison with orthologs from different microorganisms was made in order to get a phylogenetic relationships. We showed that proteins that are responsible for the affinity and specificity of the alkanesulfonate, sulfate and taurine transport systems conserved the residues involved in the sulfate coordination but are organized in different branches in evolution. Inside these phylogenetic branches, proteins involved in the sulfate transporter are highly conserved when compared to the others. Moreover, we identified that the taurine-binding protein (TauA) of the X. citri belongs to a different evolutionary branch from that one that described for E. coli. These differences were also noticed for components of the tau operon, including a putative new regulator. The function and mechanism of action of each protein is discussed in order to bring light for the sulfur assimilation processes and their importance for X. citri physiology. (author)

  9. Abandonment of the low level outlet structure at the McGregor South Dam

    Energy Technology Data Exchange (ETDEWEB)

    Mack, D.L; Murray, T.K. [Klohn-Crippen Consultants Ltd., Calgary, AB (Canada); Soutar, B.M. [Alberta Transportation, Edmonton, AB (Canada)

    2008-07-01

    The Carseland-Bow River Headworks (CBRH) is a major multi-purpose water delivery system, situated in southern Alberta. It supplies water to 87,000 hectares of agricultural land and several municipalities. The system was originally built starting in 1909. It consists of diversion works on the Bow River, 65 kilometres of canal, and the McGregor and Little Bow reservoirs. In the 1950s, the system was rehabilitated by the Prairie Farm Rehabilitation Administration (PFRA), and Travers Reservoir was added in 1954. In 1973, ownership and operation of the CBRH system was turned over to Alberta Environment. In 2001, Alberta Transportation implemented a major program to rehabilitate and upgrade the CBRH system. This program included increasing the capacity of the canals and structures, and upgrading the dams to meet current dam safety guidelines. The project involved raising the north and south dams, providing an auxiliary spillway to accommodate the probable maximum flood (PMF), and rehabilitating the existing reservoir inlet and low level outlet structures. This paper discussed the abandonment of the existing low level outlet structure located within the south dam. The paper discussed the existing dams and outlet structure as well as the south dam and outlet structure. The abandonment of the existing low level outlet structure was discussed in terms of general construction; demolition; upstream conduits and gatewell; and downstream conduit. Several illustrations and photographs of the dam and the demolition were presented. It was concluded that the in-place abandonment of the existing low level outlet structure at the McGregor South Dam provides significant advantages, including eliminating the need to construct and remove an extensive cofferdam within the reservoir. 6 refs., 2 tabs., 4 figs.

  10. Evidence for host plant preference by Iphiseiodes quadripilis (Acari: Phytoseiidae) on Citrus.

    Science.gov (United States)

    Villanueva, Raul T; Childers, Carl C

    2006-01-01

    In this study, we present field and laboratory evidence on the preference of Iphiseiodes quadripilis (Banks) for grapefruit (Citrus paradisi Macfadyen) leaves compared with sweet orange (Citrus sinensis (L.) Osbeck) leaves. This preference was confirmed in four orchards whether leaf samples were taken from either border trees of contiguous grapefruit or sweet orange or interior row trees with both citrus species in adjacent rows. Iphiseiodes quadripilis was most abundant in grapefruit trees in spite of the greater abundance of the Texas citrus mite, Eutetranychus banksi (McGregor) (Acari: Tetranychidae) in sweet orange trees. Similar preference responses were observed in laboratory tests using a Y-tube olfactometer whether I. quadripilis were collected from sweet orange or grapefruit. Iphiseiodes quadripilis collected from grapefruit trees showed significant preference for grapefruit over sweet orange leaves in contact choice tests using an arena of alternating leaf strips (12 mm long x 2 mm wide) of sweet orange and grapefruit. However, I. quadripilis collected from sweet orange trees did not show preference for either grapefruit or sweet orange leaves. Based on these results, grapefruit leaves foster some unknown factor or factors that retain I. quadripilis in greater numbers compared with sweet orange leaves.

  11. Disrupting Mating Behavior of Diaphorina citri (Liviidae).

    Science.gov (United States)

    Lujo, S; Hartman, E; Norton, K; Pregmon, E A; Rohde, B B; Mankin, R W

    2016-12-01

    Severe economic damage from citrus greening disease, caused by 'Candidatus Liberibacter asiaticus' bacteria, has stimulated development of methods to reduce mating and reproduction in populations of its insect vector, Diaphorina citri (Hemiptera: Liviidae). Male D. citri find mating partners by walking on host plants, intermittently producing vibrational calls that stimulate duetting replies by receptive females. The replies provide orientational feedback, assisting the search process. To test a hypothesis that D. citri mating can be disrupted using vibrational signals that compete with and/or mask female replies, courtship bioassays were conducted in citrus trees with or without interference from female reply mimics produced by a vibrating buzzer. Statistically significant reductions occurred in the rates and proportions of mating when the buzzer produced reply mimics within 0.4 s after male courtship calls compared with undisturbed controls. Observations of courtship behaviors in the two bioassays revealed activity patterns that likely contributed to the reductions. In both disruption and control tests, males reciprocated frequently between structural bifurcations and other transition points where signal amplitudes changed. Males in the disruption bioassay had to select among vibrational signals combined from the buzzer and the female at each transition point. They often turned towards the buzzer instead of the female. There was a statistically significant reduction in the proportion of males mating if they contacted the buzzer, possibly due to its higher vibration amplitude and duration in comparison with female replies. Potential applications of D. citri mating disruption technology in citrus groves are discussed. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

  12. Expression of Xylella fastidiosa RpfF in citrus disrupts signaling in Xanthomonas citri subsp. citri and thereby its virulence.

    Science.gov (United States)

    Caserta, R; Picchi, S C; Takita, M A; Tomaz, J P; Pereira, W E L; Machado, M A; Ionescu, M; Lindow, S; De Souza, A A

    2014-11-01

    Xylella fastidiosa and Xanthomonas citri subsp. citri, that cause citrus variegated chlorosis (CVC) and citrus canker diseases, respectively, utilize diffusible signal factor (DSF) for quorum sensing. DSF, produced by RpfF, are similar fatty acids in both organisms, although a different set of genes is regulated by DSF in each species. Because of this similarity, Xylella fastidiosa DSF might be recognized and affect the biology of Xanthomonas citri. Therefore, transgenic Citrus sinensis and Carrizo citrange plants overexpressing the Xylella fastidiosa rpfF were inoculated with Xanthomonas citri and changes in symptoms of citrus canker were observed. X. citri biofilms formed only at wound sites on transgenic leaves and were thicker; however, bacteria were unable to break through the tissue and form pustules elsewhere. Although abundant growth of X. citri occurred at wound sites on inoculated transgenic leaves, little growth was observed on unwounded tissue. Genes in the DFS-responsive core in X. citri were downregulated in bacteria isolated from transgenic leaves. DSF-dependent expression of engA was suppressed in cells exposed to xylem sap from transgenic plants. Thus, altered symptom development appears to be due to reduced expression of virulence genes because of the presence of antagonists of DSF signaling in X. citri in rpfF-expressing plants.

  13. Presencia de Diaphorina citri (Hemiptera: Psyllidae en el Noroeste Argentino (NOA Record of Diaphorina citri (Hemiptera: Psyllidae in North West Argentina

    Directory of Open Access Journals (Sweden)

    Lucrecia Augier

    2006-12-01

    Full Text Available Se amplía la distribución de Diaphorina citri Kuwayama (Hemiptera: Psyllidae para el Noroeste Argentino.The distribution of Diaphorina citri Kuwayama (Hemiptera: Psyllidae is expanded to North West Argentina.

  14. McEvoy, Kieran; McGregor, Lorna, Transitional Justice from below. Grassroots Activism and the Struggle for Change

    Directory of Open Access Journals (Sweden)

    José M. Atiles-Osoria

    2012-10-01

    Full Text Available El texto editado por Kieran McEvoy y Lorna McGregor representa un esfuerzo por repensar, redefinir e introducir un debate en el seno de la literatura y de las corrientes de estudio sobre la justicia transicional. Generalmente, la justicia transicional ha sido pensada como un conglomerado de estrategias jurídico‑políticas y socio‑económicas implementadas para lidiar con las violaciones de los derechos humanos, con la violencia política del pasado y los procesos de reconstrucción del Estado pos...

  15. Air temperature optimisation for humidity-controlled cold storage of the predatory mites Neoseiulus californicus and Phytoseiulus persimilis (Acari: Phytoseiidae).

    Science.gov (United States)

    Ghazy, Noureldin Abuelfadl; Suzuki, Takeshi; Amano, Hiroshi; Ohyama, Katsumi

    2014-03-01

    Humidity-controlled cold storage, in which the water vapour pressure is saturated, can prolong the survival of the predatory mites Neoseiulus californicus (McGregor) and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae). However, information on the optimum air temperature for long-term storage by this method is limited. The authors evaluated the survival of mated adult females of N. californicus and P. persimilis at 5.0, 7.5, 10.0 and 12.5 °C under saturated water vapour condition (vapour pressure deficit 0.0 kPa). N. californicus showed a longer survival time than P. persimilis at all the air temperatures. The longest mean survival time of N. californicus was 11 weeks at 7.5 °C, whereas that of P. persimilis was 8 weeks at 5.0 °C. After storage at 7.5 °C for 8 weeks, no negative effect on post-storage oviposition was observed in N. californicus, whereas the oviposition of P. persimilis stored at 5.0 °C for 8 weeks was significantly reduced. The interspecific variation in the response of these predators to low air temperature might be attributed to their natural habitat and energy requirements. These results may be useful for the long-term storage of these predators, which is required for cost-effective biological control. © 2013 Society of Chemical Industry.

  16. Genetic similarity among Agistemus pallinii Matioli et al (Acari: Stigmaeidae) found in citrus orchards in Vicosa, Minas Gerais state, Brazil

    International Nuclear Information System (INIS)

    Matioli, Andre L.; Pallini, Angelo; Tavares, Mara G.

    2009-01-01

    Stigmaeidae are very important predators of mite and insect pests on several crops in Brazil. It is considered the second most important family of predatory mites in citrus orchards in Brazil. However, their identification, especially that of the members of the genus Agistemus, is rather difficult based only on morphology. Hence, this study describes the use of random amplified polymorphic DNA (RAPD-PCR) markers to determine the genetic similarity of an Agistemus pallinii Matioli et al population found in 2004 in a citrus orchard in Vicosa, Minas Gerais State, Brazil, preying on Panonychus citri (McGregor). Amplifications were performed with 12 random primers (OPAA8, OPAA19, OPAB1, OPAB5, OPAB18, OPAC9, OPAC17, OPAC19, OPAD10, OPAE9, OPAE12 and OPAE17), which generated 119 bands, with 53.8% polymorphism. The coefficients of genetic similarity among the individuals ranged from 0.68 to 0.99, indicating a high genetic similarity among them. The 3D projection analysis clustered the majority of individuals confirming their high similarity. Though individuals of A. pallinii are minute (± 360 μm long), the PCR-RAPD technique can still be used for their identification, complementing morphological analyses or for comparison of populations collected in different geographic regions. This is the fi rst molecular study carried out with stigmaeid mites. (author)

  17. Genetic similarity among Agistemus pallinii Matioli et al (Acari: Stigmaeidae) found in citrus orchards in Vicosa, Minas Gerais state, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Matioli, Andre L. [Instituto Biologico, Campinas, SP (Brazil). Lab. de Entomologia Economica], e-mail: almatioli@biologico.sp.gov.br; Pallini, Angelo [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Biologia Animal], e-mail: pallini@ufv.br; Tavares, Mara G. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Biologia Geral], e-mail: mtavares@ufv.br

    2009-03-15

    Stigmaeidae are very important predators of mite and insect pests on several crops in Brazil. It is considered the second most important family of predatory mites in citrus orchards in Brazil. However, their identification, especially that of the members of the genus Agistemus, is rather difficult based only on morphology. Hence, this study describes the use of random amplified polymorphic DNA (RAPD-PCR) markers to determine the genetic similarity of an Agistemus pallinii Matioli et al population found in 2004 in a citrus orchard in Vicosa, Minas Gerais State, Brazil, preying on Panonychus citri (McGregor). Amplifications were performed with 12 random primers (OPAA8, OPAA19, OPAB1, OPAB5, OPAB18, OPAC9, OPAC17, OPAC19, OPAD10, OPAE9, OPAE12 and OPAE17), which generated 119 bands, with 53.8% polymorphism. The coefficients of genetic similarity among the individuals ranged from 0.68 to 0.99, indicating a high genetic similarity among them. The 3D projection analysis clustered the majority of individuals confirming their high similarity. Though individuals of A. pallinii are minute ({+-} 360 {mu}m long), the PCR-RAPD technique can still be used for their identification, complementing morphological analyses or for comparison of populations collected in different geographic regions. This is the fi rst molecular study carried out with stigmaeid mites. (author)

  18. Ultraviolet irradiation mutagenesis and recombination in spiroplasma citri

    Energy Technology Data Exchange (ETDEWEB)

    Labarere, J.; Barroso, G. (Bordeaux-2 Univ., 33 (France))

    1984-09-01

    A method for obtaining and screening uv-induced mutants from Spiroplasma citri is described. Lethality response curves showed that S. citri is more sensitive to uv irradiation than are other microorganisms. The presence of a shoulder in the lethality response curve showed the existence of systems able to repair uv-induced DNA damages. Toxic-resistant mutants have been obtained. A uv fluence equal to 10 J/m/sup 2/ multiplied by 2.5x10/sup 3/ gave the spontaneous mutation frequency. Arsenic acid- and xylitol-resistant mutants were used to investigate transfer of genetic information in S. citri. After 90 min of incubation, the recombination frequency was 5x10/sup -5/.

  19. The human side of science education: Using McGregor's theory Y as a framework for improving student motivation*.

    Science.gov (United States)

    Markwell, John

    2004-09-01

    Student motivation is correlated with learning. Douglas McGregor's Theory X and Theory Y as a basis for understanding and improving motivation in the business world can be directly applied to the science classroom. Teachers with a Theory Y perspective (students naturally want to learn) provide increased motivation for students and promote more active learning than Theory X-style teachers who do not view students as active learners. Many teachers are not aware of their Theory X/Theory Y orientation and how this bias may be impacting their interaction with students. This article explores the benefits of moving from a Theory X to a more Theory Y style of teaching. Copyright © 2004 International Union of Biochemistry and Molecular Biology, Inc.

  20. In Vitro and In Vivo Antibacterial Activity of Some Organic and Inorganic Salts Against Asiatic Citrus Canker Agent Xanthomonas Citri Subsp. Citri

    Directory of Open Access Journals (Sweden)

    Vahideh Hasabi

    2014-07-01

    Full Text Available Asiatic citrus canker caused by Xanthomonas citri subsp. citri is becoming a disease of high economic impact, affecting all types of important citrus crops. In this study, the potential antibacterial activity of ten organic and inorganic salts on X. citri subsp. citri and on citrus canker disease development was evaluated. Among the salt compounds, copper, iron and zinc inorganic salts particularly zinc (with the highest diameter of inhibition, the lowest MIC and MBC values and the highest bacterial growth inhibitory effect had direct antibacterial activity and strongly reduced the development of canker disease and bacterial population of lime plants.

  1. Ectopic accumulation of linalool confers resistance to Xanthomonas citri subsp. citri in transgenic sweet orange plants.

    Science.gov (United States)

    Shimada, Takehiko; Endo, Tomoko; Rodríguez, Ana; Fujii, Hiroshi; Goto, Shingo; Matsuura, Takakazu; Hojo, Yuko; Ikeda, Yoko; Mori, Izumi C; Fujikawa, Takashi; Peña, Leandro; Omura, Mitsuo

    2017-05-01

    In order to clarify whether high linalool content in citrus leaves alone induces strong field resistance to citrus canker caused by Xanthomonas citri subsp. citri (Xcc), and to assess whether this trait can be transferred to a citrus type highly sensitive to the bacterium, transgenic 'Hamlin' sweet orange (Citrus sinensis L. Osbeck) plants over-expressing a linalool synthase gene (CuSTS3-1) were generated. Transgenic lines (LIL) with the highest linalool content showed strong resistance to citrus canker when spray inoculated with the bacterium. In LIL plants inoculated by wounding (multiple-needle inoculation), the linalool level was correlated with the repression of the bacterial titer and up-regulation of defense-related genes. The exogenous application of salicylic acid, methyl jasmonate or linalool triggered responses similar to those constitutively induced in LIL plants. The linalool content in Ponkan mandarin leaves was significantly higher than that of leaves from six other representative citrus genotypes with different susceptibilities to Xcc. We propose that linalool-mediated resistance might be unique to citrus tissues accumulating large amounts of volatile organic compounds in oil cells. Linalool might act not only as a direct antibacterial agent, but also as a signal molecule involved in triggering a non-host resistance response against Xcc. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. In vitro control of Alternaria citri using antifungal potentials of ...

    African Journals Online (AJOL)

    In vitro control of Alternaria citri using antifungal potentials of Trichoderma species. Asma Murtaza, Shazia Shafique, Tehmina Anjum, Sobiya Shafique. Abstract. The antifungal potential of five species of Trichoderma viz., Trichoderma viride, Trichoderma aureoviride, Trichoderma reesei, Trichoderma koningii and ...

  3. The complete mitochondrial genome sequence of Diaphorina citri (Hemiptera: Psyllidae)

    Science.gov (United States)

    The first complete mitochondrial genome (mitogenome) sequence of Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae), from Guangzhou, China is presented. The circular mitogenome is 14,996 bp in length with an A+T content of 74.5%, and contains 13 protein-coding genes (PCGs), 22 tRNA genes ...

  4. Male Diaphorina citri searching responses to vibrational communication signals

    Science.gov (United States)

    Prototype devices have been developed that mimic D. citri female replies to male communication signals and lure males to a trap. The objective is to trap a high proportion of males that have landed on a host tree and have begun searching for females. This presentation describes the construction and ...

  5. Reaction of detached leaves of different varieties of sweet orange (Citrus sinensis L. Osbeck) to inoculation with Xanthomonas citri subsp. citri (ex Hasse) Gabriel et al.

    Science.gov (United States)

    Asiatic citrus canker (ACC) (caused by Xanthomonas citri subsp citri, Xcc) is a major disease of citrus in wet tropical and subtropical production regions. Screening for resistance is important to breeding programs. The objective of this study was to evaluate a detached leaf method to compare nine d...

  6. Complete Genome Sequence of the Largest Known Flavi-Like Virus, Diaphorina citri flavi-like virus, a Novel Virus of the Asian Citrus Psyllid, Diaphorina citri

    OpenAIRE

    Matsumura, Emilyn E.; Nerva, Luca; Nigg, Jared C.; Falk, Bryce W.; Nouri, Shahideh

    2016-01-01

    A novel flavi-like virus tentatively named Diaphorina citri flavi-like virus (DcFLV) was identified in field populations of Diaphorina citri through small RNA and transcriptome sequencing followed by reverse transcription (RT)-PCR. We report here the complete nucleotide sequence and genome organization of DcFLV, the largest flavi-like virus identified to date.

  7. Insights into xanthomonas axonopodis pv. Citri biofilm through proteomics

    KAUST Repository

    Zimaro, Tamara

    2013-08-07

    Background: Xanthomonas axonopodis pv. Citri (X. a. pv. Citri) causes citrus canker that can result in defoliation and premature fruit drop with significant production losses worldwide. Biofilm formation is an important process in bacterial pathogens and several lines of evidence suggest that in X. a. pv. Citri this process is a requirement to achieve maximal virulence since it has a major role in host interactions. In this study, proteomics was used to gain further insights into the functions of biofilms. Results: In order to identify differentially expressed proteins, a comparative proteomic study using 2D difference gel electrophoresis was carried out on X. a. pv. Citri mature biofilm and planktonic cells. The biofilm proteome showed major variations in the composition of outer membrane proteins and receptor or transport proteins. Among them, several porins and TonB-dependent receptor were differentially regulated in the biofilm compared to the planktonic cells, indicating that these proteins may serve in maintaining specific membrane-associated functions including signaling and cellular homeostasis. In biofilms, UDP-glucose dehydrogenase with a major role in exopolysaccharide production and the non-fimbrial adhesin YapH involved in adherence were over-expressed, while a polynucleotide phosphorylase that was demonstrated to negatively control biofilm formation in E. coli was down-regulated. In addition, several proteins involved in protein synthesis, folding and stabilization were up-regulated in biofilms. Interestingly, some proteins related to energy production, such as ATP-synthase were down-regulated in biofilms. Moreover, a number of enzymes of the tricarboxylic acid cycle were differentially expressed. In addition, X. a. pv. Citri biofilms also showed down-regulation of several antioxidant enzymes. The respective gene expression patterns of several identified proteins in both X. a. pv. Citri mature biofilm and planktonic cells were evaluated by

  8. New species of Uropodina from Madagascar (Acari: Mesostigmata)

    Czech Academy of Sciences Publication Activity Database

    Kontschán, J.; Starý, Josef

    2014-01-01

    Roč. 3895, č. 4 (2014), s. 547-569 ISSN 1175-5326 Institutional support: RVO:60077344 Keywords : Acari * Mesostigmata * Uropodina * new genus * new species * Madagascar Subject RIV: EG - Zoology Impact factor: 0.906, year: 2014

  9. Repellent Activity of Botanical Oils against Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae

    Directory of Open Access Journals (Sweden)

    Emily H. Kuhns

    2016-07-01

    Full Text Available The Asian citrus psyllid, Diaphorina citri Kuwayama, is the insect vector of the pathogen causing huanglongbing. We selected three botanical oils to evaluate behavioral activity against D. citri. In laboratory olfactometer assays, fir oil was repellent to D. citri females, while litsea and citronella oils elicited no response from D. citri females. In choice settling experiments, D. citri settled almost completely on control plants rather than on plants treated with fir oil at a 9.5 mg/day release rate. Therefore, we conducted field trials to determine if fir oil reduced D. citri densities in citrus groves. We found no repellency of D. citri from sweet orange resets that were treated with fir oil dispensers releasing 10.4 g/day/tree as compared with control plots. However, we found a two-week decrease in populations of D. citri as compared with controls when the deployment rate of these dispensers was doubled. Our results suggest that treatment of citrus with fir oil may have limited activity as a stand-alone management tool for D. citri and would require integration with other management practices.

  10. Repellent Activity of Botanical Oils against Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Kuhns, Emily H; Martini, Xavier; Hoyte, Angel; Stelinski, Lukasz L

    2016-07-14

    The Asian citrus psyllid, Diaphorina citri Kuwayama, is the insect vector of the pathogen causing huanglongbing. We selected three botanical oils to evaluate behavioral activity against D. citri. In laboratory olfactometer assays, fir oil was repellent to D. citri females, while litsea and citronella oils elicited no response from D. citri females. In choice settling experiments, D. citri settled almost completely on control plants rather than on plants treated with fir oil at a 9.5 mg/day release rate. Therefore, we conducted field trials to determine if fir oil reduced D. citri densities in citrus groves. We found no repellency of D. citri from sweet orange resets that were treated with fir oil dispensers releasing 10.4 g/day/tree as compared with control plots. However, we found a two-week decrease in populations of D. citri as compared with controls when the deployment rate of these dispensers was doubled. Our results suggest that treatment of citrus with fir oil may have limited activity as a stand-alone management tool for D. citri and would require integration with other management practices.

  11. Citrus flush shoot ontogeny modulates biotic potential of Diaphorina citri.

    Science.gov (United States)

    Cifuentes-Arenas, Juan Camilo; de Goes, António; de Miranda, Marcelo Pedreira; Beattie, George Andrew Charles; Lopes, Silvio Aparecido

    2018-01-01

    The biology and behaviour of the psyllid Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Liviidae), the major insect vector of bacteria associated with huanglongbing, have been extensively studied with respect to host preferences, thermal requirements, and responses to visual and chemical volatile stimuli. However, development of the psyllid in relation to the ontogeny of immature citrus flush growth has not been clearly defined or illustrated. Such information is important for determining the timing and frequency of measures used to minimize populations of the psyllid in orchards and spread of HLB. Our objective was to study how flush ontogeny influences the biotic potential of the psyllid. We divided citrus flush growth into six stages within four developmental phases: emergence (V1), development (V2 and V3), maturation (V4 and V5), and dormancy (V6). Diaphorina citri oviposition and nymph development were assessed on all flush stages in a temperature controlled room, and in a screen-house in which ambient temperatures varied. Our results show that biotic potential of Diaphorina citri is not a matter of the size or the age of the flushes (days after budbreak), but the developmental stage within its ontogeny. Females laid eggs on flush V1 to V5 only, with the time needed to commence oviposition increasing with the increasing in flush age. Stages V1, V2 and V3 were most suitable for oviposition, nymph survival and development, and adult emergence, which showed evidence of protandry. Flush shoots at emerging and developmental phases should be the focus of any chemical or biological control strategy to reduce the biotic potential of D. citri, to protect citrus tree from Liberibacter infection and to minimize HLB dissemination.

  12. Complete Genome Sequence of a Putative Densovirus of the Asian Citrus Psyllid, Diaphorina citri.

    Science.gov (United States)

    Nigg, Jared C; Nouri, Shahideh; Falk, Bryce W

    2016-07-28

    Here, we report the complete genome sequence of a putative densovirus of the Asian citrus psyllid, Diaphorina citri Diaphorina citri densovirus (DcDNV) was originally identified through metagenomics, and here, we obtained the complete nucleotide sequence using PCR-based approaches. Phylogenetic analysis places DcDNV between viruses of the Ambidensovirus and Iteradensovirus genera. Copyright © 2016 Nigg et al.

  13. Innate immune system capabilities of the Asian citrus psyllid, Diaphorina citri.

    Science.gov (United States)

    Arp, Alex P; Martini, Xavier; Pelz-Stelinski, Kirsten S

    2017-09-01

    Citrus production worldwide is currently threatened by Huanglongbing, or citrus greening disease. The associated pathogen, Candidatus Liberibacter asiaticus (CLas), is transmitted by the Asian citrus psyllid, Diaphorina citri. Annotation of the D. citri genome revealed a reduced innate immune system lacking a number of antimicrobial peptides and the Imd pathway associated with defense against Gram-negative bacteria. We characterized this apparent immune reduction in survival assays in which D. citri were exposed to Gram-negative or Gram-positive bacteria. D. citri experienced significant mortality when exposed to Serratia marcescens (Gram-negative) through oral ingestion or by septic injury. Escherichia coli (Gram-negative) also caused significant D. citri mortality, but only when inoculated at high concentrations through oral ingestion or by septic injury. Neither Micrococcus luteus (Gram-positive) or Bacillus subtilis (Gram-positive) caused significant mortality as compared to controls in any experiment. E. coli titers increased rapidly following exposure, while M. luteus titer remained stable for 72 h. We demonstrate that D. citri is capable of defending against E. coli, a Gram-negative bacterium, despite lacking the Imd defense pathway. The tolerance of D. citri to M. luteus infection, yet inability to effectively clear infections, presents questions to efficacy of D. citri immune response to effectively clear Gram-positive infections. Copyright © 2017. Published by Elsevier Inc.

  14. Complete Genome Sequence of a Putative Densovirus of the Asian Citrus Psyllid, Diaphorina citri

    OpenAIRE

    Nigg, Jared C.; Nouri, Shahideh; Falk, Bryce W.

    2016-01-01

    Here, we report the complete genome sequence of a putative densovirus of the Asian citrus psyllid, Diaphorina citri. Diaphorina citri densovirus (DcDNV) was originally identified through metagenomics, and here, we obtained the complete nucleotide sequence using PCR-based approaches. Phylogenetic analysis places DcDNV between viruses of the Ambidensovirus and Iteradensovirus genera.

  15. Complete Genome Sequence of Diaphorina citri-associated C virus, a Novel Putative RNA Virus of the Asian Citrus Psyllid, Diaphorina citri

    OpenAIRE

    Nouri, Shahideh; Salem, Nid?; Falk, Bryce W.

    2016-01-01

    We present here the complete nucleotide sequence and genome organization of a novel putative RNA virus identified in field populations of the Asian citrus psyllid, Diaphorina citri, through sequencing of the transcriptome followed by reverse transcription-PCR (RT-PCR). We tentatively named this virus Diaphorina citri-associated C virus (DcACV). DcACV is an unclassified positive-sense RNA virus.

  16. Complete Genome Sequence of Diaphorina citri-associated C virus, a Novel Putative RNA Virus of the Asian Citrus Psyllid, Diaphorina citri.

    Science.gov (United States)

    Nouri, Shahideh; Salem, Nidà; Falk, Bryce W

    2016-07-21

    We present here the complete nucleotide sequence and genome organization of a novel putative RNA virus identified in field populations of the Asian citrus psyllid, Diaphorina citri, through sequencing of the transcriptome followed by reverse transcription-PCR (RT-PCR). We tentatively named this virus Diaphorina citri-associated C virus (DcACV). DcACV is an unclassified positive-sense RNA virus. Copyright © 2016 Nouri et al.

  17. Complete Genome Sequence of the Largest Known Flavi-Like Virus, Diaphorina citri flavi-like virus, a Novel Virus of the Asian Citrus Psyllid, Diaphorina citri.

    Science.gov (United States)

    Matsumura, Emilyn E; Nerva, Luca; Nigg, Jared C; Falk, Bryce W; Nouri, Shahideh

    2016-09-08

    A novel flavi-like virus tentatively named Diaphorina citri flavi-like virus (DcFLV) was identified in field populations of Diaphorina citri through small RNA and transcriptome sequencing followed by reverse transcription (RT)-PCR. We report here the complete nucleotide sequence and genome organization of DcFLV, the largest flavi-like virus identified to date. Copyright © 2016 Matsumura et al.

  18. Molecular study on the carAB operon reveals that carB gene is required for swimming and biofilm formation in Xanthomonas citri subsp. citri.

    Science.gov (United States)

    Zhuo, Tao; Rou, Wei; Song, Xue; Guo, Jing; Fan, Xiaojing; Kamau, Gicharu Gibson; Zou, Huasong

    2015-10-23

    The carA and carB genes code the small and large subunits of carbamoyl-phosphate synthase (CPS) that responsible for arginine and pyrimidine production. The purpose of this work was to study the gene organization and expression pattern of carAB operon, and the biological functions of carA and carB genes in Xanthomonas citri subsp. citri. RT-PCR method was employed to identify the full length of carAB operon transcript in X. citri subsp. citri. The promoter of carAB operon was predicted and analyzed its activity by fusing a GUS reporter gene. The swimming motility was tested on 0.25% agar NY plates with 1% glucose. Biofilm was measured by cell adhesion to polyvinyl chloride 96-well plate. The results indicated that carAB operon was composed of five gene members carA-orf-carB-greA-rpfE. A single promoter was predicted from the nucleotide sequence upstream of carAB operon, and its sensitivity to glutamic acid, uracil and arginine was confirmed by fusing a GUS reporter gene. Deletion mutagenesis of carB gene resulted in reduced abilities in swimming on soft solid media and in forming biofilm on polystyrene microtiter plates. From these results, we concluded that carAB operon was involved in multiple biological processes in X. citri subsp. citri.

  19. The novel virulence-related gene nlxA in the lipopolysaccharide cluster of Xanthomonas citri ssp. citri is involved in the production of lipopolysaccharide and extracellular polysaccharide, motility, biofilm formation and stress resistance.

    Science.gov (United States)

    Yan, Qing; Hu, Xiufang; Wang, Nian

    2012-10-01

    Lipopolysaccharide (LPS) is an important virulence factor of Xanthomonas citri ssp. citri, the causative agent of citrus canker disease. In this research, a novel gene, designated as nlxA (novel LPS cluster gene of X. citri ssp. citri), in the LPS cluster of X. citri ssp. citri 306, was characterized. Our results indicate that nlxA is required for O-polysaccharide biosynthesis by encoding a putative rhamnosyltransferase. This is supported by several lines of evidence: (i) NlxA shares 40.14% identity with WsaF, which acts as a rhamnosyltransferase; (ii) sodium dodecylsulphate-polyacrylamide gel electrophoresis analysis showed that four bands of the O-antigen part of LPS were missing in the LPS production of the nlxA mutant; this is also consistent with a previous report that the O-antigen moiety of LPS of X. citri ssp. citri is composed of a rhamnose homo-oligosaccharide; (iii) mutation of nlxA resulted in a significant reduction in the resistance of X. citri ssp. citri to different stresses, including sodium dodecylsulphate, polymyxin B, H(2)O(2), phenol, CuSO(4) and ZnSO(4). In addition, our results indicate that nlxA plays an important role in extracellular polysaccharide production, biofilm formation, stress resistance, motility on semi-solid plates, virulence and in planta growth in the host plant grapefruit. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  20. Spatiotemporal dynamics of the Southern California Asian citrus psyllid (Diaphorina citri) invasion.

    Science.gov (United States)

    Bayles, Brett R; Thomas, Shyam M; Simmons, Gregory S; Grafton-Cardwell, Elizabeth E; Daugherty, Mathew P

    2017-01-01

    Biological invasions are governed by spatial processes that tend to be distributed in non-random ways across landscapes. Characterizing the spatial and temporal heterogeneities of the introduction, establishment, and spread of non-native insect species is a key aspect of effectively managing their geographic expansion. The Asian citrus psyllid (Diaphorina citri), a vector of the bacterium associated with huanglongbing (HLB), poses a serious threat to commercial and residential citrus trees. In 2008, D. citri first began expanding northward from Mexico into parts of Southern California. Using georeferenced D. citri occurrence data from 2008-2014, we sought to better understand the extent of the geographic expansion of this invasive vector species. Our objectives were to: 1) describe the spatial and temporal distribution of D. citri in Southern California, 2) identify the locations of statistically significant D. citri hotspots, and 3) quantify the dynamics of anisotropic spread. We found clear evidence that the spatial and temporal distribution of D. citri in Southern California is non-random. Further, we identified the existence of statistically significant hotspots of D. citri occurrence and described the anisotropic dispersion across the Southern California landscape. For example, the dominant hotspot surrounding Los Angeles showed rapid and strongly asymmetric spread to the south and east. Our study demonstrates the feasibility of quantitative invasive insect risk assessment with the application of a spatial epidemiology framework.

  1. Spatiotemporal dynamics of the Southern California Asian citrus psyllid (Diaphorina citri invasion.

    Directory of Open Access Journals (Sweden)

    Brett R Bayles

    Full Text Available Biological invasions are governed by spatial processes that tend to be distributed in non-random ways across landscapes. Characterizing the spatial and temporal heterogeneities of the introduction, establishment, and spread of non-native insect species is a key aspect of effectively managing their geographic expansion. The Asian citrus psyllid (Diaphorina citri, a vector of the bacterium associated with huanglongbing (HLB, poses a serious threat to commercial and residential citrus trees. In 2008, D. citri first began expanding northward from Mexico into parts of Southern California. Using georeferenced D. citri occurrence data from 2008-2014, we sought to better understand the extent of the geographic expansion of this invasive vector species. Our objectives were to: 1 describe the spatial and temporal distribution of D. citri in Southern California, 2 identify the locations of statistically significant D. citri hotspots, and 3 quantify the dynamics of anisotropic spread. We found clear evidence that the spatial and temporal distribution of D. citri in Southern California is non-random. Further, we identified the existence of statistically significant hotspots of D. citri occurrence and described the anisotropic dispersion across the Southern California landscape. For example, the dominant hotspot surrounding Los Angeles showed rapid and strongly asymmetric spread to the south and east. Our study demonstrates the feasibility of quantitative invasive insect risk assessment with the application of a spatial epidemiology framework.

  2. Inter-Population Variability of Endosymbiont Densities in the Asian Citrus Psyllid (Diaphorina citri Kuwayama).

    Science.gov (United States)

    Chu, Chia-Ching; Gill, Torrence A; Hoffmann, Mark; Pelz-Stelinski, Kirsten S

    2016-05-01

    The Asian citrus psyllid (Diaphorina citri Kuwayama) is an insect pest capable of transmitting Candidatus Liberibacter asiaticus (CLas), the causal agent of citrus greening in North America. D. citri also harbors three endosymbionts, Wolbachia, Candidatus Carsonella ruddii, and Candidatus Profftella armatura, which may influence D. citri physiology and fitness. Although genomic researches on these bacteria have been conducted, much remains unclear regarding their ecology and inter-population variability in D. citri. The present work examined the densities of each endosymbiont in adult D. citri sampled from different populations using quantitative PCR. Under field conditions, the densities of all three endosymbionts positively correlated with each other, and they are associated with D. citri gender and locality. In addition, the infection density of CLas also varied across populations. Although an analysis pooling D. citri from different populations showed that CLas-infected individuals tended to have lower endosymbiont densities compared to uninfected individuals, the difference was not significant when the population was included as a factor in the analysis, suggesting that other population-specific factors may have stronger effects on endosymbiont densities. To determine whether there is a genetic basis to the density differences, endosymbiont densities between aged CLas-negative females of two D. citri populations reared under standardized laboratory conditions were compared. Results suggested that inter-population variability in Wolbachia infection density is associated with the genotypes of the endosymbiont or the host. Findings from this work could facilitate understanding of D. citri-bacterial associations that may benefit the development of approaches for managing citrus greening, such as prevention of CLas transmission.

  3. New genes of Xanthomonas citri subsp. citri involved in pathogenesis and adaptation revealed by a transposon-based mutant library.

    Science.gov (United States)

    Laia, Marcelo L; Moreira, Leandro M; Dezajacomo, Juliana; Brigati, Joice B; Ferreira, Cristiano B; Ferro, Maria I T; Silva, Ana C R; Ferro, Jesus A; Oliveira, Julio C F

    2009-01-16

    Citrus canker is a disease caused by the phytopathogens Xanthomonas citri subsp. citri, Xanthomonas fuscans subsp. aurantifolli and Xanthomonas alfalfae subsp. citrumelonis. The first of the three species, which causes citrus bacterial canker type A, is the most widely spread and severe, attacking all citrus species. In Brazil, this species is the most important, being found in practically all areas where citrus canker has been detected. Like most phytobacterioses, there is no efficient way to control citrus canker. Considering the importance of the disease worldwide, investigation is needed to accurately detect which genes are related to the pathogen-host adaptation process and which are associated with pathogenesis. Through transposon insertion mutagenesis, 10,000 mutants of Xanthomonas citri subsp. citri strain 306 (Xcc) were obtained, and 3,300 were inoculated in Rangpur lime (Citrus limonia) leaves. Their ability to cause citrus canker was analyzed every 3 days until 21 days after inoculation; a set of 44 mutants showed altered virulence, with 8 presenting a complete loss of causing citrus canker symptoms. Sequencing of the insertion site in all 44 mutants revealed that 35 different ORFs were hit, since some ORFs were hit in more than one mutant, with mutants for the same ORF presenting the same phenotype. An analysis of these ORFs showed that some encoded genes were previously known as related to pathogenicity in phytobacteria and, more interestingly, revealed new genes never implicated with Xanthomonas pathogenicity before, including hypothetical ORFs. Among the 8 mutants with no canker symptoms are the hrpB4 and hrpX genes, two genes that belong to type III secretion system (TTSS), two hypothetical ORFS and, surprisingly, the htrA gene, a gene reported as involved with the virulence process in animal-pathogenic bacteria but not described as involved in phytobacteria virulence. Nucleic acid hybridization using labeled cDNA probes showed that some of the

  4. Pengendalian Diaphorina citri (Vektor Penyakit CVPD dengan Metarrhizium anisopliae

    Directory of Open Access Journals (Sweden)

    Kardi Raharjo

    2000-07-01

    and after insect infestation. The first phase of the research phase has been conducted in Temanggung, Completely Randomize Design (CRD factorial with three time replication. Factor I: sterile water without fructose, concentration 10^6 conidia/ml without fructose, concentration 10^8 conidia/ml without fructose, concentration 10^10 conidia/ml: without fructose, sterile water + fructose 5 mg/ml, concentration 10^6 conidia/ml without fructose 5 mg/ml, concentration 10^8 conidia/ml + fructose (fungi application before insect infestation and W1 (fungi application after insect infestation. Research phase II was carried out with the best treatment combination compare with control treatment in Temanggung and Bantul. The results of experiment showed that the initial die of D. citri caused by M. anisopliae infection are on 4-6 days after application. The application of M. anisopliae at concentration 10^10 conidia/ml without fructose, applied after insect infestation was most effective. The application after insect infestation was more effective compare with application before insect infestation especially on 4 days after application, but on 35th days after application there was no significant difference. Fructose has no effect to mortality of D. citri.

  5. First report in Ghana of #Xanthomonas citri# pv. #mangiferaeindicae# causing mango bacterial canker on #Mangifera indica#

    OpenAIRE

    Pruvost, Olivier; Boyer, Claudine; Vital, Karine; Gagnevin, Lionel; De Bruno Austin, L.; Rey, Jean-Yves

    2011-01-01

    Bacterial canker of mango (or bacterial black spot), caused by Xanthomonas citri pv. mangiferaeindicae, is an economically important disease in tropical and subtropical producing areas (1). X. citri pv. mangiferaeindicae can cause severe infection in a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Several months after infection, leaf lesions dry and turn light brown or ash gray. Severe leaf infection may result in abscission. F...

  6. Dispersion patterns and sampling plans for Diaphorina citri (Hemiptera: Psyllidae) in citrus.

    Science.gov (United States)

    Sétamou, Mamoudou; Flores, Daniel; French, J Victor; Hall, David G

    2008-08-01

    The abundance and spatial dispersion of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) were studied in 34 grapefruit (Citrus paradisi Macfad.) and six sweet orange [Citrus sinensis (L.) Osbeck] orchards from March to August 2006 when the pest is more abundant in southern Texas. Although flush shoot infestation levels did not vary with host plant species, densities of D. citri eggs, nymphs, and adults were significantly higher on sweet orange than on grapefruit. D. citri immatures also were found in significantly higher numbers in the southeastern quadrant of trees than other parts of the canopy. The spatial distribution of D. citri nymphs and adults was analyzed using Iowa's patchiness regression and Taylor's power law. Taylor's power law fitted the data better than Iowa's model. Based on both regression models, the field dispersion patterns of D. citri nymphs and adults were aggregated among flush shoots in individual trees as indicated by the regression slopes that were significantly >1. For the average density of each life stage obtained during our surveys, the minimum number of flush shoots per tree needed to estimate D. citri densities varied from eight for eggs to four flush shoots for adults. Projections indicated that a sampling plan consisting of 10 trees and eight flush shoots per tree would provide density estimates of the three developmental stages of D. citri acceptable enough for population studies and management decisions. A presence-absence sampling plan with a fixed precision level was developed and can be used to provide a quick estimation of D. citri populations in citrus orchards.

  7. New Uropodina species and records from Malaysia (Acari: Mesostigmata)

    Czech Academy of Sciences Publication Activity Database

    Kontschán, J.; Starý, Josef

    2012-01-01

    Roč. 58, č. 2 (2012), s. 177-192 ISSN 1217-8837 Institutional research plan: CEZ:AV0Z60660521 Keywords : Acari * new records * new species * Malaysia Subject RIV: EH - Ecology, Behaviour Impact factor: 0.472, year: 2012

  8. Two new Uropodina species from Ethiopia (Acari: Mesostigmata)

    Czech Academy of Sciences Publication Activity Database

    Kontschán, J.; Starý, Josef

    2013-01-01

    Roč. 54, č. 1 (2013), s. 49-56 ISSN 1681-5556 Institutional research plan: CEZ:AV0Z60660521 Institutional support: RVO:60077344 Keywords : Acari * Uropodina * Afrotropical * Ethiopia * new species * new synonymy Subject RIV: EG - Zoology Impact factor: 0.500, year: 2013

  9. Different transcriptional response to Xanthomonas citri subsp. citri between kumquat and sweet orange with contrasting canker tolerance.

    Directory of Open Access Journals (Sweden)

    Xing-Zheng Fu

    Full Text Available Citrus canker disease caused by Xanthomonas citri subsp. citri (Xcc is one of the most devastating biotic stresses affecting the citrus industry. Meiwa kumquat (Fortunella crassifolia is canker-resistant, while Newhall navel orange (Citrus sinensis Osbeck is canker-sensitive. To understand the molecular mechanisms underlying the differences in responses to Xcc, transcriptomic profiles of these two genotypes following Xcc attack were compared by using the Affymetrix citrus genome GeneChip. A total of 794 and 1324 differentially expressed genes (DEGs were identified as canker-responsive genes in Meiwa and Newhall, respectively. Of these, 230 genes were expressed in common between both genotypes, while 564 and 1094 genes were only significantly expressed in either Meiwa or Newhall. Gene ontology (GO annotation and Singular Enrichment Analysis (SEA of the DEGs showed that genes related to the cell wall and polysaccharide metabolism were induced for basic defense in both Meiwa and Newhall, such as chitinase, glucanase and thaumatin-like protein. Moreover, apart from inducing basic defense, Meiwa showed specially upregulated expression of several genes involved in the response to biotic stimulus, defense response, and cation binding as comparing with Newhall. And in Newhall, abundant photosynthesis-related genes were significantly down-regulated, which may be in order to ensure the basic defense. This study revealed different molecular responses to canker disease in Meiwa and Newhall, affording insight into the response to canker and providing valuable information for the identification of potential genes for engineering canker tolerance in the future.

  10. Xanthomonas citri ssp. citri requires the outer membrane porin OprB for maximal virulence and biofilm formation.

    Science.gov (United States)

    Ficarra, Florencia A; Grandellis, Carolina; Galván, Estela M; Ielpi, Luis; Feil, Regina; Lunn, John E; Gottig, Natalia; Ottado, Jorgelina

    2017-06-01

    Xanthomonas citri ssp. citri (Xcc) causes canker disease in citrus, and biofilm formation is critical for the disease cycle. OprB (Outer membrane protein B) has been shown previously to be more abundant in Xcc biofilms compared with the planktonic state. In this work, we showed that the loss of OprB in an oprB mutant abolishes bacterial biofilm formation and adherence to the host, and also compromises virulence and efficient epiphytic survival of the bacteria. Moreover, the oprB mutant is impaired in bacterial stress resistance. OprB belongs to a family of carbohydrate transport proteins, and the uptake of glucose is decreased in the mutant strain, indicating that OprB transports glucose. Loss of OprB leads to increased production of xanthan exopolysaccharide, and the carbohydrate intermediates of xanthan biosynthesis are also elevated in the mutant. The xanthan produced by the mutant has a higher viscosity and, unlike wild-type xanthan, completely lacks pyruvylation. Overall, these results suggest that Xcc reprogrammes its carbon metabolism when it senses a shortage of glucose input. The participation of OprB in the process of biofilm formation and virulence, as well as in metabolic changes to redirect the carbon flux, is discussed. Our results demonstrate the importance of environmental nutrient supply and glucose uptake via OprB for Xcc virulence. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  11. Dinamika Populasi Diaphorina citri Kuwayama (Homoptera: Psyllidae dan Deteksi CVPD dengan Teknik PCR

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    I NYOMAN WIJAYA

    2015-09-01

    Full Text Available The research was conducted in the field of Taro village Gianyar regency and Katung village Bangli regency and at the Laboratory of Biotechnology Faculty of Agricultural Udayana University. The purpose of the research were to investigate population dynamic of Diaphorina citri Kuwayama and other insects that were assosiated with citrus cv. siam; and molecular detection of CVPD patogen in its vector, other phytophagous insects on citrus cv.siam and kemuning [Murraya paniculata (L. Jack.] The result of this study showed that in six month period there was one peak of D. citri population which was associated with the flushing period of citrus at Taro as well Katung villages. The peak of D. citri population of Taro village was higher than that of Katung village. Two species of parasitoids and four spesies of predators were found in the field and may contribute in the suppression of D. citri population. The parasitoids identified were Tamarixia radiata Wat. and Diaphorencyrtus alligharensi Shaffe, whereas the predators were Curinus coeruleus Mulsant, Phiddipus sp., Menochilus sexmaculatus Fabricius and Oxyopes javanus Thorell. T. radiata has been proven to be an effective nymph parasitoid that could suppress the population development of D. citri in citrus orchads. The research revealed that kemuning could serve as a source of infection because it is also a host of CVPD disease as well as of D. citri. Toxoptera citricidus Kirkaldy and Maleuterpes dentipes Hell. were not proven to contain CVPD disease.

  12. Genetic diversity of Diaphorina citri and its endosymbionts across east and south-east Asia.

    Science.gov (United States)

    Wang, Yanjing; Xu, Changbao; Tian, Mingyi; Deng, Xiaoling; Cen, Yijing; He, Yurong

    2017-10-01

    Diaphorina citri is the vector of 'Candidatus Liberibacter asiaticus', the most widespread pathogen associated huanglongbing, the most serious disease of citrus. To enhance our understanding of the distribution and origin of the psyllid, we investigated the genetic diversity and population structures of 24 populations in Asia and one from Florida based on the mtCOI gene. Simultaneously, genetic diversity and population structures of the primary endosymbiont (P-endosymbiont) 'Candidatus Carsonella ruddii' and secondary endosymbiont (S-endosymbiont) 'Candidatus Profftella armatura' of D. citri were determined with the housekeeping genes. AMOVA analysis indicated that populations of D. citri and its endosymbionts in east and south-east Asia were genetically distinct from populations in Pakistan and Florida. Furthermore, P-endosymbiont populations displayed a strong geographical structure across east and south-east Asia, while low genetic diversity indicated the absence of genetic structure among the populations of D. citri and its S-endosymbiont across these regions. The 'Ca. C. ruddii' is more diverse and structured than the D. citri and the 'Ca. P. armatura' across east and south-east Asia. Multiple introductions of the psyllid have occurred in China. Management application for controlling the pest is proposed based on the genetic information of D. citri and its endosymbionts. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  13. Comparative proteomic analysis of hemolymph from uninfected and Candidatus Liberibacter asiaticus-infected Diaphorina citri.

    Science.gov (United States)

    Gill, T A; Chu, C; Pelz-Stelinski, K S

    2017-02-01

    Hemolymph was characterized from Diaphorina citri adults infected with the phytopathogen, Candidatus Liberibacter asiaticus (CLas), and compared with that from uninfected psyllids. This study identified 5531 and 3220 peptides within infected and uninfected hemolymph using nano-LC-MS/MS. A reduced number of proteins were detected for D. citri and all known endosymbionts within infected hemolymph as compared to uninfected hemolymph. A large number of immune defense proteins were absent from D. citri hemolymph; however, a single recognition protein (PGRP), two serine protease inhibitors, three prophenoloxidase (proPO) enzymes, and a single serine protease in an uninfected D. citri were detected. The hemolymph is nearly devoid of nutrient storage proteins. This is the first proteomic analysis of D. citri hemolymph that also analyses the components contributed by all the endosymbionts. By comparing the contribution of each endosymbiont (CCR, CPA, and WB) in the presence and absence of CLas infection, this study offers initial insights regarding the hemolymph response to microbial community shifts associated with D. citri infection status. Our data also present potential protein targets for analysis and disruption of CLas transmission that may facilitate management of huanglongbing (HLB) caused by CLas in citrus.

  14. The LOV protein of Xanthomonas citri subsp. citri plays a significant role in the counteraction of plant immune responses during citrus canker.

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    Ivana Kraiselburd

    Full Text Available Pathogens interaction with a host plant starts a set of immune responses that result in complex changes in gene expression and plant physiology. Light is an important modulator of plant defense response and recent studies have evidenced the novel influence of this environmental stimulus in the virulence of several bacterial pathogens. Xanthomonas citri subsp. citri is the bacterium responsible for citrus canker disease, which affects most citrus cultivars. The ability of this bacterium to colonize host plants is influenced by bacterial blue-light sensing through a LOV-domain protein and disease symptoms are considerably altered upon deletion of this protein. In this work we aimed to unravel the role of this photoreceptor during the bacterial counteraction of plant immune responses leading to citrus canker development. We performed a transcriptomic analysis in Citrus sinensis leaves inoculated with the wild type X. citri subsp. citri and with a mutant strain lacking the LOV protein by a cDNA microarray and evaluated the differentially regulated genes corresponding to specific biological processes. A down-regulation of photosynthesis-related genes (together with a corresponding decrease in photosynthesis rates was observed upon bacterial infection, this effect being more pronounced in plants infected with the lov-mutant bacterial strain. Infection with this strain was also accompanied with the up-regulation of several secondary metabolism- and defense response-related genes. Moreover, we found that relevant plant physiological alterations triggered by pathogen attack such as cell wall fortification and tissue disruption were amplified during the lov-mutant strain infection. These results suggest the participation of the LOV-domain protein from X. citri subsp. citri in the bacterial counteraction of host plant defense response, contributing in this way to disease development.

  15. The LOV Protein of Xanthomonas citri subsp. citri Plays a Significant Role in the Counteraction of Plant Immune Responses during Citrus Canker

    Science.gov (United States)

    Kraiselburd, Ivana; Daurelio, Lucas D.; Tondo, María Laura; Merelo, Paz; Cortadi, Adriana A.; Talón, Manuel; Tadeo, Francisco R.; Orellano, Elena G.

    2013-01-01

    Pathogens interaction with a host plant starts a set of immune responses that result in complex changes in gene expression and plant physiology. Light is an important modulator of plant defense response and recent studies have evidenced the novel influence of this environmental stimulus in the virulence of several bacterial pathogens. Xanthomonas citri subsp. citri is the bacterium responsible for citrus canker disease, which affects most citrus cultivars. The ability of this bacterium to colonize host plants is influenced by bacterial blue-light sensing through a LOV-domain protein and disease symptoms are considerably altered upon deletion of this protein. In this work we aimed to unravel the role of this photoreceptor during the bacterial counteraction of plant immune responses leading to citrus canker development. We performed a transcriptomic analysis in Citrus sinensis leaves inoculated with the wild type X. citri subsp. citri and with a mutant strain lacking the LOV protein by a cDNA microarray and evaluated the differentially regulated genes corresponding to specific biological processes. A down-regulation of photosynthesis-related genes (together with a corresponding decrease in photosynthesis rates) was observed upon bacterial infection, this effect being more pronounced in plants infected with the lov-mutant bacterial strain. Infection with this strain was also accompanied with the up-regulation of several secondary metabolism- and defense response-related genes. Moreover, we found that relevant plant physiological alterations triggered by pathogen attack such as cell wall fortification and tissue disruption were amplified during the lov-mutant strain infection. These results suggest the participation of the LOV-domain protein from X. citri subsp. citri in the bacterial counteraction of host plant defense response, contributing in this way to disease development. PMID:24260514

  16. Temperature studies with the Asian citrus psyllid, Diaphorina citri: cold hardiness and temperature thresholds for oviposition.

    Science.gov (United States)

    Hall, David G; Wenninger, Erik J; Hentz, Matthew G

    2011-01-01

    This study was conducted to obtain information on the cold hardiness of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), in Florida and to assess upper and lower temperature thresholds for oviposition. The psyllid is an important pest in citrus because it transmits the bacterial pathogens responsible for citrus greening disease, Huanglongbing, considered the most serious citrus disease worldwide. D. citri was first found in Florida during 1998, and the disease was discovered during 2005. Little was known regarding cold hardiness of D. citri, but Florida citrus is occasionally subjected to notable freeze events. Temperature and duration were each significant sources of variation in percent mortality of D. citri subjected to freeze events. Relatively large percentages of adults and nymphs survived after being exposed for several hours to temperatures as low as -5 to -6 °C. Relatively large percentages of eggs hatched after being exposed for several hours to temperatures as low as -8 °C. Research results indicated that adult D. citri become cold acclimated during the winter through exposure to cooler winter temperatures. There was no evidence that eggs became cold acclimated during winter. Cold acclimation in nymphs was not investigated. Research with adult D. citri from laboratory and greenhouse colonies revealed that mild to moderate freeze events were usually nonlethal to the D. citri irrespective of whether they were cold acclimated or not. Upper and lower temperature thresholds for oviposition were investigated because such information may be valuable in explaining the geographic distribution and potential spread of the pest from Florida as well as how cooler winter temperatures might limit population growth. The estimated lower and upper thresholds for oviposition were 16.0 and 41.6 °C, respectively; the estimated temperature of peak oviposition over a 48 h period was 29.6 °C.

  17. Within-orchard edge effects of the azimuth of the sun on Diaphorina citri adults in mature orchards

    Science.gov (United States)

    Huanglongbing (HLB) has been considered the most devastating disease of citrus. The bacterium and vector associated with HLB in Florida are ‘Candidatus Liberibacter asiaticus’ and Diaphorina citri (Asian citrus psyllid), respectively. D. citri is positively phototropic, and higher populations have b...

  18. Living on the Edges: Spatial Niche Occupation of Asian Citrus Psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), in Citrus Groves.

    Science.gov (United States)

    Sétamou, Mamoudou; Bartels, David W

    2015-01-01

    The spatial niche occupation of the Asian citrus psyllid, Diaphorina citri Kuwayama, 1908, was evaluated to determine its field colonization and food resource exploitation strategies in citrus groves. Mature grapefruit and sweet orange groves were surveyed as part of an area-wide program in 2009-2010 to determine D. citri population densities and between-tree distribution. In both cultivars, significantly more psyllids were found on perimeter trees throughout the study period suggesting a strong edge effect in D. citri distribution in the groves. D. citri densities and infestation levels gradually declined from the edge to the center of grove. Higher numbers of D. citri were recorded on trees located on the east and south sides of the groves than those on the west and north sides. Citrus groves located at the outer edge of the study with at least one side non-surrounded to other citrus groves harbored significantly more D. citri than groves located within the block cluster and entirely surrounded by other groves. In detailed field studies during 2012, infestation of D. citri started from border trees in the grove where possibly one generation is completed before inner trees become infested. In addition, psyllid densities decreased significantly with increasing distance from the grove edge. Using the selection index, D citri exhibited a strong niche occupation preference for border trees.

  19. An assessment of interspecific competition between two introduced parasitoids of Diaphorina citri (Hemiptera: Liviidae) on caged citrus plants.

    Science.gov (United States)

    Vankosky, Meghan A; Hoddle, Mark S

    2017-06-07

    Two parasitoids attacking nymphs of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) and Diaphorencyrtus aligarhensis (Shafee, Alam & Agarwal) (Hymenoptera: Encyrtidae) are being released in California, USA in a classical biological control program. To evaluate the effect of multiple parasitoid species on D. citri mortality, we conducted mesocosm experiments under controlled conditions using a complete block design with 6 treatments (D. citri nymphs exposed to: no parasitoids; D. aligarhensis or T. radiata alone; D. aligarhensis or T. radiata released first (by 48 h); and both species released simultaneously). Parasitism of D. citri nymphs by T. radiata exceeded 60% and was unchanged when D. aligarhensis were present. Parasitism by D. aligarhensis was greatest when T. radiata was absent (∼28%) and was reduced in all treatments with T. radiata present (citri mortality and parasitoid-related mortality of D. citri was consistent across parasitoid treatments. Laboratory results suggest that competition between D. aligarhensis and T. radiata is asymmetric and favors T. radiata. It may be difficult for D. aligarhensis to contribute significantly to D. citri biological control where T. radiata is present. However, results reported here suggest that competition between T. radiata and D. aligarhensis is not likely to reduce parasitism by T. radiata or reduce parasitoid-induced mortality of D. citri. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  20. Killing Effects of an Isolated Serratia marcescens KH-001 on Diaphorina citri via Lowering the Endosymbiont Numbers.

    Science.gov (United States)

    Hu, Wei; Kuang, Fan; Lu, Zhanjun; Zhang, Ning; Chen, Tingtao

    2018-01-01

    Huanglongbing (HLB) is the most devastating citrus disease worldwide, and suppression of the Asian citrus psyllid ( Diaphorina citri ) is regarded as an effective method to inhibit the spread of HLB. In this study, we isolated a strain named as Serratia marcescens KH-001 from D. citri nymphs suffering from disease, and evaluated its killing effect on D. citri via toxicity test and effect on microbial community in D. citri using high-throughput sequencing. Our results indicated that S. marcescens KH-001 could effectively kill 83% of D. citri nymphs, while the fermentation products of S. marcescens KH-001 only killed 40% of the D. citri nymphs. High-throughput sequencing results indicated that the S. marcescens KH-001 increased the OTU numbers from 62.5 (PBS buffer) to 81.5, while significantly lowered the Shannon index compared with Escherichia coli DH5α (group E) ( p citri endow S. marcescens KH-001 a sound killing effect on D. citri . Further work need to do before this strain is used as a sound biological control agents.

  1. Diaphorina citri nymphs are resistant to morphological changes induced by “Candidatus Liberibacter asiaticus” in midgut epithelial cells

    Science.gov (United States)

    “Candidatus Liberibacter asiaticus” is the causative bacterium associated with citrus greening disease. “Ca. L. asiaticus” is transmitted by Diaphorina citri more efficiently when it is acquired by nymphs rather than adults. Why this occurs is not known. We compared midguts of D. citri reared on hea...

  2. Living on the Edges: Spatial Niche Occupation of Asian Citrus Psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae, in Citrus Groves.

    Directory of Open Access Journals (Sweden)

    Mamoudou Sétamou

    Full Text Available The spatial niche occupation of the Asian citrus psyllid, Diaphorina citri Kuwayama, 1908, was evaluated to determine its field colonization and food resource exploitation strategies in citrus groves. Mature grapefruit and sweet orange groves were surveyed as part of an area-wide program in 2009-2010 to determine D. citri population densities and between-tree distribution. In both cultivars, significantly more psyllids were found on perimeter trees throughout the study period suggesting a strong edge effect in D. citri distribution in the groves. D. citri densities and infestation levels gradually declined from the edge to the center of grove. Higher numbers of D. citri were recorded on trees located on the east and south sides of the groves than those on the west and north sides. Citrus groves located at the outer edge of the study with at least one side non-surrounded to other citrus groves harbored significantly more D. citri than groves located within the block cluster and entirely surrounded by other groves. In detailed field studies during 2012, infestation of D. citri started from border trees in the grove where possibly one generation is completed before inner trees become infested. In addition, psyllid densities decreased significantly with increasing distance from the grove edge. Using the selection index, D citri exhibited a strong niche occupation preference for border trees.

  3. Behavioral responses of male Diaphorina citri (Hemiptera: Liviidae) to mating communication signals from vibration traps in citrus (Sapindales: Rutaceae) trees

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors the bacterium causing citrus greening disease, which has devastated citrus production worldwide wherever it has been introduced. To help monitor and target D citri populations in commercial groves, thereby facilitating more effective manag...

  4. Diaphorina citri (Hemiptera: Liviidae) responses to microcontroller-buzzer communication signals of potential use in vibration traps

    Science.gov (United States)

    Monitoring of Diaphorina citri Kuwayama populations is an important component of efforts to reduce damage caused by huanglongbing, a devastating disease it vectors in citrus groves. Currently, D. citri is monitored primarily by unbaited sticky traps or visual inspection of trees. A potentially more ...

  5. Induced resistance against the Asian citrus psyllid, Diaphorina citri, by β-aminobutyric acid in citrus.

    Science.gov (United States)

    Tiwari, Siddharth; Meyer, Wendy L; Stelinski, Lukasz L

    2013-10-01

    β-Aminobutyric acid (BABA) is known to induce resistance to microbial pathogens, nematodes and insects in several host plant/pest systems. The present study was undertaken to determine whether a similar effect of BABA occurred against the Asian citrus psyllid, Diaphorina citri Kuwayama, in citrus. A 25 mM drench application of BABA significantly reduced the number of eggs/plant as compared with a water control, whereas 200 and 100 mM applications of BABA reduced the numbers of nymphs/plant and adults/plants, respectively. A 5 mM foliar application of BABA significantly reduced the number of adults but not eggs or nymphs when compared with a water control treatment. In addition, leaf-dip bioassays using various concentrations (25–500 mM) of BABA indicated no direct toxic effect on 2nd and 5th instar nymphs or adult D. citri. BABA-treated plants were characterized by significantly lower levels of iron, magnesium, phosphorus, sodium, sulfur and zinc as compared with control plants. The expression level of the PR-2 gene (β-1,3-glucanase) in BABA-treated plants that were also damaged by D. citri adult feeding was significantly higher than in plants exposed to BABA, D. citri feeding alone or control plants. Our results indicate the potential for using BABA as a systemic acquired resistance management tool for D. citri.

  6. Diaphorina citri (Hemiptera: Liviidae) Vector Competence for the Citrus Greening Pathogen 'Candidatus Liberibacter Asiaticus'.

    Science.gov (United States)

    Tabachnick, Walter J

    2015-06-01

    Characterizing the vector competence of Diaphorina citri Kuwayama for 'Candidatus Liberibacter asiaticus,' the pathogen causing citrus greening, is essential for understanding the epidemiology of this disease that is threatening the U.S. citrus industry. Vector competence studies have been difficult because of the biology of D. citri, the inability to culture the pathogen, and the available diagnostic methods used to detect the bacteria in plant and insect tissues. The methods employed in many studies of D. citri vector competence may have overestimated amounts of live 'Ca. L. asiaticus' in both plant and insect tissues, and it is possible that the amounts of phloem ingested by psyllids may not contain sufficient detectable pathogen using current diagnostic methods. As a result of the difficulty in characterizing D. citri vector competence, the several daunting challenges for providing D. citri that are unable to inoculate 'Ca. L. asiaticus', as a novel method to control greening are discussed. Suggestions to overcome some of these challenges are provided. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Host and environmental factors influencing "Candidatus Liberibacter asiaticus" acquisition in Diaphorina citri.

    Science.gov (United States)

    Wu, Fengnian; Huang, Jiaquan; Xu, Meirong; Fox, Eduardo G P; Beattie, G Andrew C; Holford, Paul; Cen, Yijing; Deng, Xiaoling

    2018-05-03

    Diaphorina citri is a vector of "Candidatus Liberibacter asiaticus" (CLas) associated with citrus Huanglongbing. In this study, the infection and titers of CLas in the psyllid, were monitored for life cycle stage, sex, host-plant CLas titer, host-plant genotype, and ambient temperature. Acquisition efficiency of CLas by D. citri was highest in nymphs reared at 25 °C on a host plant with high CLas titers but was independent of the host genotypes assessed and of vector sex. We further observed that D. citri nymphs acquired CLas more rapidly than adults based on acquisition access periods (AAPs). CLas did not multiply in the alimentary canal, hemolymph, and salivary glands of adults for 18 d after a 3-day AAP as adult. However, CLas multiplication was detected in hemolymph and salivary gland of adults after the bacterium was acquired by nymphs. Eighty percent of salivary glands of adults contained CLas 18 d after a 3-day AAP as nymph compared to 10% 18 d after a 3-day AAP as adults. Different factors tested herein influenced CLas acquisition efficiency of D. citri, CLas multiplication and spread inside the psyllid. These observations serve to better understand mechanisms of CLas infection in D. citri. This article is protected by copyright. All rights reserved.

  8. Processed kaolin affects the probing and settling behavior of Diaphorina citri (Hemiptera: Lividae).

    Science.gov (United States)

    Miranda, Marcelo P; Zanardi, Odimar Z; Tomaseto, Arthur F; Volpe, Haroldo Xl; Garcia, Rafael B; Prado, Ernesto

    2018-03-05

    Alternative methods that have the potential to reduce the entry of Diaphorina citri Kuwayama (Hemiptera: Liviidae), the major citrus pest worldwide, into commercial groves could be a viable approach for huanglongbing management. Kaolin is an aluminum silicate that when sprayed on plants forms a white particle film that interferes with host recognition by the insects. Diaphorina citri orients towards the host plants by visual and olfactory cues. The purpose of the study was to determine the effect of processed kaolin on D. citri settling (no-choice) and probing behavior [electrical penetration graph (EPG) technique] under laboratory conditions, and to study its host plant finding ability and dispersal under field conditions in the absence and presence of young shoots. Under laboratory conditions, kaolin caused an overall reduction of 40% in the number of psyllids settled on treated seedlings; furthermore, the proportion of individuals that were able to reach the phloem was 50% lower on kaolin-treated plants than on untreated plants. In the field, the plant finding ability of D. citri was disrupted on kaolin-treated trees (overall reduction of 96%), regardless of the vegetative condition, and psyllid dispersal was slower in kaolin-treated plots than in the untreated control. This study clearly demonstrates that processed kaolin interferes negatively with different aspects of the host plant finding ability of D. citri. These findings suggest that processed kaolin has a high potential to reduce huanglongbing primary infection. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  9. Dynamic insecticide susceptibility changes in Florida populations of Diaphorina citri (Hemiptera: Psyllidae).

    Science.gov (United States)

    Tiwari, Siddharth; Killiny, Nabil; Stelinski, Lukasz L

    2013-02-01

    Five field populations of Diaphorina citri Kuwayama from various regions of Florida were evaluated in 2011 for resistance to commonly used insecticides. Three diagnostic doses (LD50, LD75, and LD95), developed in 2009 using a laboratory susceptible population, were used to measure changes in susceptibility levels of field-collected populations as compared with a susceptible laboratory population. Further reductions in the susceptibility levels of D. citri to chlorpyriphos and fenpropathrin were determined, compared with results obtained in 2010. Mean percent mortality obtained from all five locations was significantly lower than observed with the laboratory susceptible population for all insecticides tested. Previously, expression of five CYP4 genes was implicated in contributing to insecticide metabolism in D. citri. In the current study, we compared the relative expression of these five CYP4 genes and their associated levels of protein expression among field-collected and laboratory susceptible populations. Expression of all CYP4 genes investigated was higher in field-collected populations when normalized against the laboratory susceptible population. There was an increased signal of a band corresponding to a 45 kDa protein in four of the five field populations as measured by the Western blot assay, which suggests increased production of cytochrome P450 enzymes. The current results indicate that insecticide resistance continues to increase in Florida populations ofD. citri, particularly to chlorpyriphos and fenpropathrin. However, there was no further decrease in susceptibility of Florida populations of D. citri to neonicotinoid insecticides in 2011 as compared with previous years.

  10. Chemical and behavioral analysis of the cuticular hydrocarbons from Asian citrus psyllid, Diaphorina citri.

    Science.gov (United States)

    Mann, Rajinder S; Rouseff, Russell L; Smoot, Jack; Rao, Nandikeswara; Meyer, Wendy L; Lapointe, Stephen L; Robbins, Paul S; Cha, Dong; Linn, Charles E; Webster, Francis X; Tiwari, Siddharth; Stelinski, Lukasz L

    2013-06-01

    Huanglongbing (HLB) is the most destructive disease of citrus worldwide. The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the vector of the phloem-inhabiting bacterium, Candidatus Liberibacter asiaticus, which is presumed to cause HLB in Florida citrus. Laboratory and field studies were conducted to examine the behavioral responses of male and female D. citri to their cuticular extracts. In olfactometer assays, more male D. citri were attracted to one, five, or 10 female cuticular extract equivalent units than blank controls. The results were confirmed in field studies in which clear or yellow traps baited with 10 female cuticular extract equivalent units attracted proportionately more males than clear traps baited with male cuticular extract or unbaited traps. Analyses of cuticular constituents of male and female D. citri revealed differences between the sexes in chemical composition of their cuticular extracts. Laboratory bioassays with synthetic chemicals identified from cuticular extracts indicated that dodecanoic acid attracted more males than clean air. Traps baited with dodecanoic acid did not increase total catch of D. citri as compared with blank traps at the dosages tested; however, the sex ratio of psyllid catch was male biased on traps baited with the highest lure loading dosage tested (10.0 mg). © 2012 The Authors Insect Science © 2012 Institute of Zoology, Chinese Academy of Sciences.

  11. Sulfur volatiles from Allium spp. affect Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), response to citrus volatiles.

    Science.gov (United States)

    Mann, R S; Rouseff, R L; Smoot, J M; Castle, W S; Stelinski, L L

    2011-02-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors Candidatus Liberibacter asiaticus (Las) and Candidatus Liberibacter americanus (Lam), the presumed causal agents of huanglongbing. D. citri generally rely on olfaction and vision for detection of host cues. Plant volatiles from Allium spp. (Alliaceae) are known to repel several arthropod species. We examined the effect of garlic chive (A. tuberosum Rottl.) and wild onion (A. canadense L.) volatiles on D. citri behaviour in a two-port divided T-olfactometer. Citrus leaf volatiles attracted significantly more D. citri adults than clean air. Volatiles from crushed garlic chive leaves, garlic chive essential oil, garlic chive plants, wild onion plants and crushed wild onion leaves all repelled D. citri adults when compared with clean air, with the first two being significantly more repellent than the others. However, when tested with citrus volatiles, only crushed garlic chive leaves and garlic chive essential oil were repellent, and crushed wild onions leaves were not. Analysis of the headspace components of crushed garlic chive leaves and garlic chive essential oil by gas chromatography-mass spectrometry revealed that monosulfides, disulfides and trisulfides were the primary sulfur volatiles present. In general, trisulfides (dimethyl trisulfide) inhibited the response of D. citri to citrus volatiles more than disulfides (dimethyl disulfide, allyl methyl disulfide, allyl disulfide). Monosulfides did not affect the behaviour of D. citri adults. A blend of dimethyl trisulfide and dimethyl disulfide in 1:1 ratio showed an additive effect on inhibition of D. citri response to citrus volatiles. The plant volatiles from Allium spp. did not affect the behaviour of the D. citri ecto-parasitoid Tamarixia radiata (Waterston). Thus, Allium spp. or the tri- and di-sulphides could be integrated into management programmes for D. citri without affecting natural enemies.

  12. Gross morphology and ultrastructure of the female reproductive system of Diaphorina citri (Hemiptera: Liviidae

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    Fabio Cleisto Alda Dossi

    2014-04-01

    Full Text Available The morphological traits of the female reproductive system of Diaphorina citri were examined in detail. Diaphorina citri has telotrophic ovaries with ovarioles organized as a "bouquet", displaying a rudimentary terminal filament and a syncytial tropharium. The vitellarium carries a single growing oocyte at each maturation cycle, which is connected with the tropharium by a nutritive cord. Morpho-functional changes occur during oocyte development, mainly during mid to late vitellogenesis. Morphological events such as the patency of the follicular cells and the intense traffic of vesicles through para- or intracellular processes, suggest a possible route for endosymbiont invasion of D. citri reproductive tissues. Similar events have been demonstrated to be involved in the process of ovariole invasion by endosymbionts in other sternorrhynchans that share reproductive traits with psyllids.

  13. Effects of buprofezin and diflubenzuron on various developmental stages of Asian citrus psyllid, Diaphorina citri.

    Science.gov (United States)

    Tiwari, Siddharth; Clayson, Paul J; Kuhns, Emily H; Stelinski, Lukasz L

    2012-10-01

    Diaphorina citri populations in Florida are developing resistance to commonly used neurotoxic insecticides. Alternatives to neurotoxins, such as insect growth regulators, are needed to control this season-long subtropical pest to prevent or delay development of insecticide resistance. In the present investigation, two insect growth regulators (IGRs), buprofezin and diflubenzuron, were evaluated against various developmental stages of D. citri. The 0-1-day-old D. citri eggs were more susceptible to buprofezin and diflubenzuron than the 3-4-day-old eggs. Adult emergence was completely suppressed by treating first- or third-instar nymphs with buprofezin or diflubenzuron at 30-240 or 23-184 µg mL(-1) rates respectively. Treatment of fifth-instar nymphs with diflubenzuron at a rate of 184 µg mL(-1) and with buprofezin at 30-240 µg mL(-1) rates resulted in approximately 20 and 15-80% reductions in adult emergence respectively. The mean number of eggs per plant was reduced at 5 days after topical treatment with diflubenzuron. Mean egg hatch per plant was reduced at 5 and 6-15 days after topical treatments with buprofezin and diflubenzuron respectively. Buprofezin and diflubenzuron effectively suppressed D. citri adult emergence. D. citri were more susceptible as early (first-third-instar) than late (fifth-instar) nymphs. Both IGRs inhibited egg production and egg hatch. Reduction in the number of subsequent offspring suggests reduced vertical transmission of Candidatus Liberibacter asiaticus, the pathogen thought to cause citrus greening disease. The present results indicate that both IGRs tested here should be effective tools for rotation in insecticide-based D. citri management programs. Copyright © 2012 Society of Chemical Industry.

  14. Characterization of the voltage-gated sodium channel of the Asian citrus psyllid, Diaphorina citri.

    Science.gov (United States)

    Liu, Bin; Coy, Monique R; Wang, Jin-Jun; Stelinski, Lukasz L

    2017-02-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important insect pest of citrus. It is the vector of 'Candidatus' Liberibacter asiaticus, a phloem-limited bacterium that infects citrus, resulting in the disease Huanglongbing (HLB). Disease management relies heavily on suppression of D. citri populations with insecticides, including pyrethroids. In recent annual surveys to monitor insecticide resistance, reduced susceptibility to fenpropathrin was identified in several field populations of D. citri. The primary target of pyrethroids is the voltage-gated sodium channel (VGSC). The VGSC is prone to target-site insensitivity because of mutations that either reduce pyrethroid binding and/or alter gating kinetics. These mutations, known as knockdown resistance or kdr, have been reported in a wide diversity of arthropod species. Alternative splicing, in combination with kdr mutations, has been also associated with reduced pyrethroid efficacy. Here we report the molecular characterization of the VGSC in D. citri along with a survey of alternative splicing across developmental stages of this species. Previous studies demonstrated that D. citri has an exquisite enzymatic arsenal to detoxify insecticides resulting in reduced efficacy. The results from the current investigation demonstrate that target-site insensitivity is also a potential basis for insecticide resistance to pyrethroids in D. citri. The VGSC sequence and its molecular characterization should facilitate early elucidation of the underlying cause of an established case of resistance to pyrethroids. This is the first characterization of a VGSC from a hemipteran to this level of detail, with the majority of the previous studies on dipterans and lepidopterans. © 2015 Institute of Zoology, Chinese Academy of Sciences.

  15. First Record of Diaphorina citri (Hemiptera: Psyllidae) in Ecuador Infesting Urban Citrus and Orange Jasmine Trees

    Science.gov (United States)

    Cornejo, J.F.; Chica, E.J.

    2014-01-01

    Abstract Adults and nymphs of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), were collected in the Guayaquil, Samborondón, and Durán cantons in coastal Ecuador. Psyllids were found in high numbers in citrus ( Citrus spp., Sapindales: Rutaceae) and orange jasmine ( Murraya exotica [L.] Jack, Sapindales: Rutaceae) trees within the Guayaquil-Samborondon-Duran conurbation; however, none was found during scoutings in the main citrus producing areas in coastal Ecuador. To the best of our knowledge, this is the first report of D. citri in Ecuador and the Pacific coastal plain of South America. PMID:25527601

  16. PRIMER REPORTE DE LA PRESENCIA DE Diaphorina citri (HEMIPTERA: LIVIIDAE EN MANABÍ

    Directory of Open Access Journals (Sweden)

    José Bernardo Navarrete Cedeño

    2016-12-01

    Full Text Available Diaphorina citri (Hemiptera: Liviidae, conocido como el psílido asiático de los cítricos, es considerada una plaga clave de la citricultura mundial, debido a que es vector de la bacteria “Candidatus Liberibacter”, agente causal de la enfermedad “Huanglongbing”, que tiene efectos letales sobre vegetales dentro de la familia Rutaceae. En este documento se reporta la presencia de D. citri infestando Murraya spp., un arbusto de la familia Rutaceae, en la zona urbana del cantón Portoviejo. Este es el primer reporte de la plaga en la provincia de Manabí-Ecuador

  17. Host plant affects morphometric variation of Diaphorina citri (Hemiptera: Liviidae

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    Thomson M. Paris

    2016-11-01

    Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri Kuwayama, is one of the most serious citrus pests worldwide due to its role as vector of huanglongbing or citrus greening disease. While some optimal plant species for ACP oviposition and development have been identified, little is known of the influence of host plants on ACP size and shape. Our goal was to determine how size and shape of ACP wing and body size varies when development occurs on different host plants in a controlled rearing environment. ACP were reared on six different rutaceous species; Bergera koenigii, Citrus aurantifolia, Citrus macrophylla, Citrus maxima, Citrus taiwanica and Murraya paniculata. Adults were examined for morphometric variation using traditional and geometric analysis based on 12 traits or landmarks. ACP reared on C. taiwanica were consistently smaller than those reared on the other plant species. Wing aspect ratio also differed between C. maxima and C. taiwanica. Significant differences in shape were detected with those reared on M. paniculata having narrower wings than those reared on C. macrophylla. This study provides evidence of wing size and shape differences of ACP based on host plant species which potentially may impact dispersal. Further study is needed to determine if behavioral and physiological differences are associated with the observed phenotypic differences.

  18. Host plant affects morphometric variation of Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Paris, Thomson M; Allan, Sandra A; Hall, David G; Hentz, Matthew G; Hetesy, Gabriella; Stansly, Philip A

    2016-01-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is one of the most serious citrus pests worldwide due to its role as vector of huanglongbing or citrus greening disease. While some optimal plant species for ACP oviposition and development have been identified, little is known of the influence of host plants on ACP size and shape. Our goal was to determine how size and shape of ACP wing and body size varies when development occurs on different host plants in a controlled rearing environment. ACP were reared on six different rutaceous species; Bergera koenigii , Citrus aurantifolia , Citrus macrophylla , Citrus maxima , Citrus taiwanica and Murraya paniculata . Adults were examined for morphometric variation using traditional and geometric analysis based on 12 traits or landmarks. ACP reared on C. taiwanica were consistently smaller than those reared on the other plant species. Wing aspect ratio also differed between C. maxima and C. taiwanica . Significant differences in shape were detected with those reared on M. paniculata having narrower wings than those reared on C. macrophylla . This study provides evidence of wing size and shape differences of ACP based on host plant species which potentially may impact dispersal. Further study is needed to determine if behavioral and physiological differences are associated with the observed phenotypic differences.

  19. An Ecoinformatics Approach to Field-Scale Evaluation of Insecticide Effects in California Citrus: Are Citrus Thrips and Citrus Red Mite Induced Pests?

    Science.gov (United States)

    Livingston, George; Hack, Lindsey; Steinmann, Kimberly P; Grafton-Cardwell, Elizabeth E; Rosenheim, Jay A

    2018-05-28

    Experimental approaches to studying the consequences of pesticide use, including impacts on beneficial insects, are vital; however, they can be limited in scale and realism. We show that an ecoinformatics approach that leverages existing data on pesticides, pests, and beneficials across multiple fields can provide complementary insights. We do this using a multi-year dataset (2002-2013) on pesticide applications and density estimates of two pests, citrus thrips (Scirtothrips citri (Moulton [Thysanoptera: Thripidae])) and citrus red mites (Panonychus citri McGregor [Acari: Tetranychidae]), and a natural enemy (Euseius spp. predatory mites) collected from citrus groves in the San Joaquin Valley of California. Using correlative analyses, we investigated the long-term consequences of pesticide use on S. citri and P. citri population densities to evaluate the hypothesis that the pest status of these species is largely due to the disruption of natural biological control-i.e., these are induced pests. We also evaluated short-term pesticide efficacy (suppression of citrus thrips and citrus red mite populations immediately post-application) and asked if it was correlated with the suppression of Euseius predator populations. Although the short-term efficacy of different pesticides varied significantly, our dataset does not suggest that the use of citrus pesticides suppressed Euseius densities or worsened pest problems. We also find that there is no general trade-off between pesticide efficacy and pesticide risk to Eusieus, such that highly effective and minimally disruptive compounds were available to citrus growers during the studied time period.

  20. Identification of Immunity-Related Genes in Dialeurodes citri against Entomopathogenic Fungus Lecanicillium attenuatum by RNA-Seq Analysis.

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    Shijiang Yu

    Full Text Available Dialeurodes citri is a major pest in citrus producing areas, and large-scale outbreaks have occurred increasingly often in recent years. Lecanicillium attenuatum is an important entomopathogenic fungus that can parasitize and kill D. citri. We separated the fungus from corpses of D. citri larvae. However, the sound immune defense system of pests makes infection by an entomopathogenic fungus difficult. Here we used RNA sequencing technology (RNA-Seq to build a transcriptome database for D. citri and performed digital gene expression profiling to screen genes that act in the immune defense of D. citri larvae infected with a pathogenic fungus. De novo assembly generated 84,733 unigenes with mean length of 772 nt. All unigenes were searched against GO, Nr, Swiss-Prot, COG, and KEGG databases and a total of 28,190 (33.3% unigenes were annotated. We identified 129 immunity-related unigenes in transcriptome database that were related to pattern recognition receptors, information transduction factors and response factors. From the digital gene expression profile, we identified 441 unigenes that were differentially expressed in D. citri infected with L. attenuatum. Through calculated Log2Ratio values, we identified genes for which fold changes in expression were obvious, including cuticle protein, vitellogenin, cathepsin, prophenoloxidase, clip-domain serine protease, lysozyme, and others. Subsequent quantitative real-time polymerase chain reaction analysis verified the results. The identified genes may serve as target genes for microbial control of D. citri.

  1. Identification of Immunity-Related Genes in Dialeurodes citri against Entomopathogenic Fungus Lecanicillium attenuatum by RNA-Seq Analysis.

    Science.gov (United States)

    Yu, Shijiang; Ding, Lili; Luo, Ren; Li, Xiaojiao; Yang, Juan; Liu, Haoqiang; Cong, Lin; Ran, Chun

    2016-01-01

    Dialeurodes citri is a major pest in citrus producing areas, and large-scale outbreaks have occurred increasingly often in recent years. Lecanicillium attenuatum is an important entomopathogenic fungus that can parasitize and kill D. citri. We separated the fungus from corpses of D. citri larvae. However, the sound immune defense system of pests makes infection by an entomopathogenic fungus difficult. Here we used RNA sequencing technology (RNA-Seq) to build a transcriptome database for D. citri and performed digital gene expression profiling to screen genes that act in the immune defense of D. citri larvae infected with a pathogenic fungus. De novo assembly generated 84,733 unigenes with mean length of 772 nt. All unigenes were searched against GO, Nr, Swiss-Prot, COG, and KEGG databases and a total of 28,190 (33.3%) unigenes were annotated. We identified 129 immunity-related unigenes in transcriptome database that were related to pattern recognition receptors, information transduction factors and response factors. From the digital gene expression profile, we identified 441 unigenes that were differentially expressed in D. citri infected with L. attenuatum. Through calculated Log2Ratio values, we identified genes for which fold changes in expression were obvious, including cuticle protein, vitellogenin, cathepsin, prophenoloxidase, clip-domain serine protease, lysozyme, and others. Subsequent quantitative real-time polymerase chain reaction analysis verified the results. The identified genes may serve as target genes for microbial control of D. citri.

  2. Killing Effects of an Isolated Serratia marcescens KH-001 on Diaphorina citri via Lowering the Endosymbiont Numbers

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    Wei Hu

    2018-05-01

    Full Text Available Huanglongbing (HLB is the most devastating citrus disease worldwide, and suppression of the Asian citrus psyllid (Diaphorina citri is regarded as an effective method to inhibit the spread of HLB. In this study, we isolated a strain named as Serratia marcescens KH-001 from D. citri nymphs suffering from disease, and evaluated its killing effect on D. citri via toxicity test and effect on microbial community in D. citri using high-throughput sequencing. Our results indicated that S. marcescens KH-001 could effectively kill 83% of D. citri nymphs, while the fermentation products of S. marcescens KH-001 only killed 40% of the D. citrinymphs. High-throughput sequencing results indicated that the S. marcescens KH-001 increased the OTU numbers from 62.5 (PBS buffer to 81.5, while significantly lowered the Shannon index compared with Escherichia coli DH5α (group E (p < 0.05. OTU analysis showed that the S. marcescens KH-001 had significantly reduced the relative abundance of endosymbionts Wolbachia, Profftella, and Carsonella in group S compared with that in other groups (p < 0.05. Therefore, the direct killing effect of the fermentation products of S. marcescens KH-001 and the indirect effect via reducing the numbers of endosymbionts (Wolbachia, Profftella, and Carsonella of D. citri endow S. marcescens KH-001 a sound killing effect on D. citri. Further work need to do before this strain is used as a sound biological control agents.

  3. New records of water mites (Acari: Hydrachnidia, Halacaroidea) from Patagonia (Chile)

    NARCIS (Netherlands)

    Pešić, V.; Smit, H.; Datry, T.

    2010-01-01

    New records of water mite species (Acari: Hydrachnidia, Halacaroidea) from Patagonia (Southern Chile) are reported. Four species, Anisitsiellides australis Smit, 2002, Peregrinacarus falklandensis Bartsch, 2001, Lobohalacarus weberi (Romijn & Viets, 1924) and Soldanellonyx monardi Walter, 1919 are

  4. Temperature-dependent development and reproductive traits of Tetranychus macfarlanei (Acari: Tetranychidae)

    DEFF Research Database (Denmark)

    Ullah, Mohammad Shaef; Haque, Md. Ahsanul; Nachman, Gösta

    2012-01-01

    Development and reproductive traits of Tetranychus macfarlanei Baker & Pritchard (Acari: Tetranychidae) were investigated on kidney bean, Phaseolus vulgaris L., at eleven constant temperatures. Tetranychus macfarlanei was able to develop and complete its life cycle at temperatures ranging from 17...

  5. Three new .i.Trachyuropoda./i. (Acari: Uropodina: Trachyuropodidae) species from the Neotropical region

    Czech Academy of Sciences Publication Activity Database

    Kontschán, J.; Starý, Josef

    2013-01-01

    Roč. 37, č. 1 (2013), s. 7-14 ISSN 1300-0179 Institutional support: RVO:60077344 Keywords : Acari * Uropodina * Trachyuropoda * Galápagos Islands Subject RIV: EG - Zoology Impact factor: 0.585, year: 2013

  6. First report of Aculops lycopersici (Tryon, 1917 (Acari: Eriophyidae on Pepino in Turkey

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    Rana Akyazi

    2012-12-01

    Full Text Available The tomato russet mite, Aculops lycopersici (Tryon, 1917 (Acari: Eriophyidae is reported for the first time on Pepino (Solanum muricatum Aiton in Ordu and Samsun provinces in Turkey.

  7. A new genus and species Mangalaus krishianusandhanus (Acari: Eriophyidae) from India

    Science.gov (United States)

    Mangalaus ikrishianusandhanus n. gen., n. sp., (Acari: Prostigmata: Eriophyoidea), collected from erineum on the underside of leaves of Cordia dichotoma (Boraginaceae) is described and illustrated from specimens collected at the Indian Agricultural Research Institute (IARI) in New Delhi, India....

  8. Molecular Detection of Spiroplasma Citri Associated with Stubborn Disease in Citrus Orchards in Syria

    Science.gov (United States)

    Spiroplasma citri, a phloem-limited pathogen, causes citrus stubborn disease (CSD) and can be transmitted from plant to plant by several species of phloem-feeding leafhoppers. CSD is an important disorder in certain warm and arid citrus-growing areas, and its agent has been recorded from several Med...

  9. Geïntegreerde bestrijding van citruswolluis Planococcus citri in roos

    NARCIS (Netherlands)

    Pijnakker, J.; Leman, A.; Hennekam, M.

    2013-01-01

    Citruswolluis, Planococcus citri (Risso), is een van de belangrijkste plagen geworden in de rozenteelt onder glas. Er is inmiddels veel praktijkervaring met de toepassing van biologische bestrijders om haarden uit te roeien. Voor de professionele tuinbouw is de effectiviteit van deze aanpak

  10. Population diversity of Diaphorina citri (Hemiptera: Liviidae) in China based on whole mitochondrial genome sequences

    Science.gov (United States)

    BACKGROUND: Diaphorina citri (Asian citrus psyllid, ACP) transmits “Candidatus Liberibacter asiaticus”, an unculturable alpha-proteobacterium associated with citrus Huanglongbing (HLB). ACP has been reported in 11 provinces/regions in China, yet its population diversity remains unclear. In this stud...

  11. [Ovarian development and analysis of mating effects on ovary maturation of Diaphorina citri Kuwayama (Hemiptera: Psyllidae)].

    Science.gov (United States)

    Dossi, Fábio C A; Cônsoli, Fernando L

    2010-01-01

    As many other insects with a restricted diet, the citrus psyllid Diaphorina citri Kuwayama, which vector the causing agent of the Huanglongbing, the bacteria Candidatus Liberibacter spp., is intimately associated with symbiotic microorganisms. These mutualist symbionts play a key role on their host nutritional ecology, and are vertically transmitted to the progeny. However, despite the role symbionts play on host development and reproduction, and the growing opportunities of exploitation of the association insect-symbiont to control insect vectored-pathogens, there are very few studies on the host reproductive biology and on the symbiont transovarial transmission. Therefore, we aimed at analyzing the ovary development during D. citri adulthood, and at verifying for the mating requirement as a trigger to initiate ovary development. Newly-emerged D. citri females were grouped as virgin or mated and ovary development was observed during adulthood. Newly-emerged females have immature ovaries, and ovaries remain without any mature eggs until females mate. Once female mates, the vitellogenesis synthesis and uptake are estimulated, and oocytes are quickly developed. Oocytes maturation in ovarioles is metachronic, with only one oocyte developing at a time in each oogenic cycle. Morphological observations of the reproductive system including the ovaries and spermatheca, after the first cluster of eggs is laid, indicated D. citri is polyandrous, and may require multiple mating to develop additional oogenic maturation cycles.

  12. Responses of Diaphorina citri (Hemiptera: Psyllidae) to conspecific vibrational signals and synthetic mimics

    Science.gov (United States)

    Mate-seeking in Diaphorina citri Kuwayama, a vector of the economically damaging huanglongbing citrus disease, typically includes male-female duetting behaviors. First, the male calls by beating its wings at ca. 170-250 Hz, producing vibrations that are transmitted along the host tree branches to th...

  13. Diaphorina citri (Hemiptera: Liviidae) Abundance in Puerto Rico Declines with Elevation.

    Science.gov (United States)

    Jenkins, David A; Hall, David G; Goenaga, Ricardo

    2015-02-01

    Diaphorina citri Kuwayama is the primary vector of Huanglongbing, the most devastating disease of citrus. D. citri populations in Puerto Rico were monitored with yellow sticky traps on citrus trees or other psyllid host plants at different elevations, ranging from 10 to 880 m above sea level. Trapping was conducted in March through May of 2013 and 2014 when psyllid populations usually are highest. Population levels of D. citri, based on the trapping data, varied among the sites, and there was a strong trend in both years for decreasing psyllid abundance with increased elevation based on the number of psyllids captured on traps and the proportion of trees shown to be infested. No psyllids were collected at an elevation of >600 m. Reduced populations at higher elevations could be a consequence of differences in temperature, air pressure, oxygen levels, ultraviolet light, or other factors alone or in combination. We discuss our results as they pertain to management of D. citri and Huanglongbing. Published by Oxford University Press on behalf of Entomological Society of America. 2015. This work is written by US Government employees and is in the public domain in the US.

  14. Morphometric comparisons of Diaphorina citri (Hemiptera: Liviidae populations from Iran, USA and Pakistan

    Directory of Open Access Journals (Sweden)

    Mohammadreza Lashkari

    2015-05-01

    Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri Kuwayama (Hemiptera: Liviidae, vector of citrus greening disease pathogen, Huanglongbing (HLB, is considered the most serious pest of citrus in the world. Prior molecular based studies have hypothesized a link between the D. citri in Iran and the USA (Florida. The purpose of this study was to collect morphometric data from D. citri populations from Iran (mtCOI haplotype-1, Florida (mtCOI haplotype-1, and Pakistan (mtCOI haplotype-6, to determine whether different mtCOI haplotypes have a relationship to a specific morphometric variation. 240 samples from 6 ACP populations (Iran—Jiroft, Chabahar; Florida—Ft. Pierce, Palm Beach Gardens, Port St. Lucie; and Pakistan—Punjab were collected for comparison. Measurements of 20 morphological characters were selected, measured and analysed using ANOVA and MANOVA. The results indicate differences among the 6 ACP populations (Wilks’ lambda = 0.0376, F = 7.29, P < 0.0001. The body length (BL, circumanal ring length (CL, antenna length (AL, forewing length (WL and Rs vein length of forewing (RL were the most important characters separating the populations. The cluster analysis showed that the Iran and Florida populations are distinct from each other but separate from the Pakistan population. Thus, three subgroups can be morphologically discriminated within D. citri species in this study, (1 Iran, (2 USA (Florida and (3 Pakistan population. Morphometric comparisons provided further resolution to the mtCOI haplotypes and distinguished the Florida and Iranian populations.

  15. The genetic structure of an invasive pest, the Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Guidolin, Aline S; Fresia, Pablo; Cônsoli, Fernando L

    2014-01-01

    The Asian citrus psyllid Diaphorina citri is currently the major threat to the citrus industry as it is the vector of Candidatus Liberibacter, the causal agent of huanglongbing disease (HLB). D. citri is native to Asia and now colonizes the Americas. Although it has been known in some countries for a long time, invasion routes remain undetermined. There are no efficient control methods for the HLB despite the intensive management tools currently in use. We investigated the genetic variability and structure of populations of D. citri to aid in the decision making processes toward sustainable management of this species/disease. We employed different methods to quantify and compare the genetic diversity and structure of D. citri populations among 36 localities in Brazil, using an almost complete sequence of the cytochrome oxidase I (COI) gene. Our analyses led to the identification of two geographically and genetically structured groups. The indices of molecular diversity pointed to a recent population expansion, and we discuss the role of multiple invasion events in this scenario. We also argue that such genetic diversity and population structure may have implications for the best management strategies to be adopted for controlling this psyllid and/or the disease it vectors in Brazil.

  16. Repellency of Selected Psidium guajava cultivars to the Asian citrus psyllid, Diaphorina citri

    Science.gov (United States)

    Asiatic huanglongbing (HLB)(also known as citrus greening disease) is the most devastating disease of citrus worldwide. It is caused by a bacterium ‘Candidatus Liberibacter asiaticus’ and transmitted by the Asian citrus psyllid (ACP), Diaphorina citri. Considerable research has been conducted toward...

  17. Draft genome sequence of “Candidatus Liberibacter asiaticus” from Diaphorina citri in Guangdong, China

    Science.gov (United States)

    The draft genome sequence of “Candidatus Liberibacter asiaticus” strain YCPsy from an Asian citrus psyllid (Diaphorina citri) in Guangdong of China is reported. The YCPsy strain has a genome size of 1,233,647 bp, 36.5% G+C content, 1,171 open reading frames (ORFs), and 53 RNAs....

  18. Morphometric comparisons of Diaphorina citri (Hemiptera: Liviidae) populations from Iran, USA and Pakistan.

    Science.gov (United States)

    Lashkari, Mohammadreza; Hentz, Matthew G; Boykin, Laura M

    2015-01-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), vector of citrus greening disease pathogen, Huanglongbing (HLB), is considered the most serious pest of citrus in the world. Prior molecular based studies have hypothesized a link between the D. citri in Iran and the USA (Florida). The purpose of this study was to collect morphometric data from D. citri populations from Iran (mtCOI haplotype-1), Florida (mtCOI haplotype-1), and Pakistan (mtCOI haplotype-6), to determine whether different mtCOI haplotypes have a relationship to a specific morphometric variation. 240 samples from 6 ACP populations (Iran-Jiroft, Chabahar; Florida-Ft. Pierce, Palm Beach Gardens, Port St. Lucie; and Pakistan-Punjab) were collected for comparison. Measurements of 20 morphological characters were selected, measured and analysed using ANOVA and MANOVA. The results indicate differences among the 6 ACP populations (Wilks' lambda = 0.0376, F = 7.29, P citri species in this study, (1) Iran, (2) USA (Florida) and (3) Pakistan population. Morphometric comparisons provided further resolution to the mtCOI haplotypes and distinguished the Florida and Iranian populations.

  19. The genetic structure of an invasive pest, the Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae.

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    Aline S Guidolin

    Full Text Available The Asian citrus psyllid Diaphorina citri is currently the major threat to the citrus industry as it is the vector of Candidatus Liberibacter, the causal agent of huanglongbing disease (HLB. D. citri is native to Asia and now colonizes the Americas. Although it has been known in some countries for a long time, invasion routes remain undetermined. There are no efficient control methods for the HLB despite the intensive management tools currently in use. We investigated the genetic variability and structure of populations of D. citri to aid in the decision making processes toward sustainable management of this species/disease. We employed different methods to quantify and compare the genetic diversity and structure of D. citri populations among 36 localities in Brazil, using an almost complete sequence of the cytochrome oxidase I (COI gene. Our analyses led to the identification of two geographically and genetically structured groups. The indices of molecular diversity pointed to a recent population expansion, and we discuss the role of multiple invasion events in this scenario. We also argue that such genetic diversity and population structure may have implications for the best management strategies to be adopted for controlling this psyllid and/or the disease it vectors in Brazil.

  20. Population genetic structure of Diaphorina citri Kuwayama (Hemiptera: Liviidae): host-driven genetic differentiation in China.

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    Meng, Lixue; Wang, Yongmo; Wei, Wen-Hua; Zhang, Hongyu

    2018-01-24

    The Asian citrus psyllid Diaphorina citri Kuwayama is a major pest in citrus production, transmitting Candidatus Liberibacter asiaticus. It has spread widely across eastern and southern China. Unfortunately, little is known about the genetic diversity and population structure of D. citri, making pest control difficult. In this study, nine specifically developed SSR markers and three known mitochondrial DNA were used for population genetics study of D. citri using 225 samples collected from all 7 distribution regions in China. Based on the SSR data, D. citri was found highly diverse with a mean observed heterozygosity of 0.50, and three subgroups were structured by host plant: (i) Shatangju, NF mandarin and Ponkan; (ii) Murraya paniculata and Lemon; (iii) Citrus unshiu, Bingtangcheng, Summer orange and Navel. No significant genetic differences were found with mtDNA data. We suggested the host-associated divergence is likely to have occurred very recently. A unimodal distribution of paired differences, the negative and significant Tajima's D and Fu's F S parameters among mtDNA suggested a recent demographic expansion. The extensive citrus cultivation and increased suitable living habitat was recommended as a key for this expansion event.

  1. The Influence of Learning on Host Plant Preference in a Significant Phytopathogen Vector, Diaphorina citri.

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    Dara G Stockton

    Full Text Available Although specialist herbivorous insects are guided by innate responses to host plant cues, host plant preference may be influenced by experience and is not dictated by instinct alone. The effect of learning on host plant preference was examined in the Asian citrus psyllid, Diaphorina citri; vector of the causal agent of citrus greening disease or huanglongbing. We investigated: a whether development on specific host plant species influenced host plant preference in mature D. citri; and b the extent of associative learning in D. citri in the form of simple and compound conditioning. Learning was measured by cue selection in a 2-choice behavioral assay and compared to naïve controls. Our results showed that learned responses in D. citri are complex and diverse. The developmental host plant species influenced adult host plant preference, with female psyllids preferring the species on which they were reared. However, such preferences were subject to change with the introduction of an alternative host plant within 24-48 hrs, indicating a large degree of experience-dependent response plasticity. Additionally, learning occurred for multiple sensory modalities where novel olfactory and visual environmental cues were associated with the host plant. However, males and females displayed differing discriminatory abilities. In compound conditioning tasks, males exhibited recognition of a compound stimulus alone while females were capable of learning the individual components. These findings suggest D. citri are dynamic animals that demonstrate host plant preference based on developmental and adult experience and can learn to recognize olfactory and visual host plant stimuli in ways that may be sex specific. These experience-based associations are likely used by adults to locate and select suitable host plants for feeding and reproduction and may suggest the need for more tailored lures and traps, which reflect region-specific cultivars or predominate

  2. Effects of Mineral Oils on Host Selection Behavior of Diaphorina citri

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    Mofit Eko Poerwanto

    2008-07-01

    Full Text Available Response of Diaphorina citri Kuwayama (Hemiptera: Psyllidae on citrus leaves treated with horticultural and agricultural mineral oil (HMO & AMO was evaluated under laboratory condition in choice and non-choice trials. Combination of HMO and AMO at concentration of 0 up to 2% was applied to citrus leaves. Mineral oil applications significantly reduced the proportion of D. citri stayed on citrus leaves for feeding with the proposed mechanisms: 1 oils covered leaves thus hampered it for releasing volatile compounds, 2 oil film preventing the direct contact of tarsus or palpus to leaf surfaces, and 3 the volatile compounds produced by mineral oils also blended with plant volatiles in the atmosphere and reduced the probability of olfactory receptors capturing the olfactory cues for locating the feeding site. Mineral oils also increased the mortality of D. citri due to the refusion for feeding on the treated citrus leaves. The effect of AMO was more prominent than HMO.   Tanggapan Diaphorina citri Kuwayama (Hemiptera: Psyllidae pada daun jeruk yang diperlakukan dengan minyak mineral (HMO dan AMO dievaluasi dengan metode pilihan maupun tanpa pilihan di laboratorium. Kombinasi antara HMO dan AMO pada konsentrasi 0% sampai dengan 2% diaplikasikan pada daun jeruk. Minyak mineral secara nyata menurunkan proporsi D. citri hinggap untuk makan pada daun jeruk, yang mungkin disebabkan oleh mekanisme: 1 minyak melapisi daun sehingga tidak mampu melepaskan senyawa volatil, 2 lapisan minyak menghalangi kontak langsung antara tarsus atau palpus pada permukaan daun, dan 3 senyawa volatil dari minyak bercampur dengan volatil tanaman di udara sehingga menurunkan probabilitas reseptor olfaktori menangkap sinyal penanda lokasi inang. Minyak mineral juga meningkatkan mortalitas, akibat dari penolakan makan pada daun jeruk yang diperlakukan. Pengaruh AMO lebih besar dari pada HMO.

  3. Insecticidal suppression of Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae vector of huanglongbing pathogens.

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    Jawwad A Qureshi

    Full Text Available Diaphorina citri vectors pathogens that cause 'huanglongbing' or citrus greening disease which poses a serious threat to citrus production worldwide. Vector suppression is critical to reduce disease spread. Efficacy is a main concern when choosing an insecticide. Insecticidal treatments of 49 products or 44 active ingredients (a.i labeled or experimental were field tested between 2005-2013 as foliar sprays (250 treatments, 39 a.i or soil applications (47 treatments, 9 a.i to control D. citri in citrus. A combined effect of nymphal and adult suppression in response to sprays of 23 insecticides representing 9 modes of action (MoA groups and 3 unknown MoA provided more than 90% reduction of adult D. citri over 24-68 days. Observable effects on nymphs were generally of shorter duration due to rapid maturation of flush. However, reduction of 76-100% nymphs or adults over 99-296 days was seen on young trees receiving drenches of the neonicotinoids imidacloprid, thiamethoxam or clothianidin (MoA 4A and a novel anthranilic diamide, cyantraniliprole (MoA 28. Effective products identified for foliar sprays to control D. citri provide sufficient MoA groups for rotation to delay evolution of insecticide resistance by D. citri and other pests. However, cyantraniliprole is now the only available alternative for rotation with neonicotinoids in soil application to young trees. Sprays of up to eight of the most effective insecticides could be rotated over a year without repetition of any MoA and little or no recourse to neonicotinoids or cyantraniliprole, so important for protection of young trees. Other considerations effecting decisions of what and when to spray include prevalence of huanglongbing, pest pressure, pre-harvest intervals, overall budget, equipment availability, and conservation of beneficial arthropods. Examples of spray programs utilizing broad-spectrum and relatively selective insecticides are provided to improve vector management and may vary

  4. Genetic variation and potential coinfection of Wolbachia among widespread Asian citrus psyllid (Diaphorina citri Kuwayama) populations.

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    Chu, Chia-Ching; Hoffmann, Mark; Braswell, W Evan; Pelz-Stelinski, Kirsten S

    2017-12-29

    Wolbachia can profoundly influence the survival, reproduction, and defenses of insect hosts. These interactions could potentially be harnessed for managing pests or insect-transmitted diseases. Diaphorina citri Kuwayama is a phloem-feeding pest capable of transmitting the putative causal agent of citrus greening, Candidatus Liberibacter asiaticus (CLas). Like many insects, D. citri is also infected with Wolbachia (wDi). Recent studies indicate that the relative abundance of wDi could be associated with the abundance of CLas, and that wDi may contribute to regulating expression of phage lytic cycle genes in CLas, suggesting the need for better understanding of wDi biology in general. This study investigated the genetic diversity of wDi among D. citri in populations spanning eleven countries and two U.S. territories. Six Wolbachia genes, wsp, coxA, fbpA, ftsZ, gatB, and hcpA, were sequenced and compared across samples. Two prevalent wDi strains were identified across the samples, and screening of clone libraries revealed possible coinfection of wDi strains in specific populations. D. citri mitochondrial cytochrome oxidase subunit I gene (mtCOI) were more divergent between D. citri populations that were infected with different wDi strains or had different infection statuses (single infection vs. coinfection). While we could not eliminate the possibility that maternal transmission may contribute to such patterns, it is also possible that wDi may induce cytoplasmic incompatibility in their host. These findings should contribute to the understanding of wDi population ecology, which may facilitate manipulation of this endosymbiont for management of citrus greening disease worldwide. © 2017 The Authors. Insect Science published by John Wiley & Sons Australia, Ltd on behalf of Institute of Zoology, Chinese Academy of Sciences.

  5. Insecticidal suppression of Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae) vector of huanglongbing pathogens.

    Science.gov (United States)

    Qureshi, Jawwad A; Kostyk, Barry C; Stansly, Philip A

    2014-01-01

    Diaphorina citri vectors pathogens that cause 'huanglongbing' or citrus greening disease which poses a serious threat to citrus production worldwide. Vector suppression is critical to reduce disease spread. Efficacy is a main concern when choosing an insecticide. Insecticidal treatments of 49 products or 44 active ingredients (a.i) labeled or experimental were field tested between 2005-2013 as foliar sprays (250 treatments, 39 a.i) or soil applications (47 treatments, 9 a.i) to control D. citri in citrus. A combined effect of nymphal and adult suppression in response to sprays of 23 insecticides representing 9 modes of action (MoA) groups and 3 unknown MoA provided more than 90% reduction of adult D. citri over 24-68 days. Observable effects on nymphs were generally of shorter duration due to rapid maturation of flush. However, reduction of 76-100% nymphs or adults over 99-296 days was seen on young trees receiving drenches of the neonicotinoids imidacloprid, thiamethoxam or clothianidin (MoA 4A) and a novel anthranilic diamide, cyantraniliprole (MoA 28). Effective products identified for foliar sprays to control D. citri provide sufficient MoA groups for rotation to delay evolution of insecticide resistance by D. citri and other pests. However, cyantraniliprole is now the only available alternative for rotation with neonicotinoids in soil application to young trees. Sprays of up to eight of the most effective insecticides could be rotated over a year without repetition of any MoA and little or no recourse to neonicotinoids or cyantraniliprole, so important for protection of young trees. Other considerations effecting decisions of what and when to spray include prevalence of huanglongbing, pest pressure, pre-harvest intervals, overall budget, equipment availability, and conservation of beneficial arthropods. Examples of spray programs utilizing broad-spectrum and relatively selective insecticides are provided to improve vector management and may vary depending on

  6. The Influence of Learning on Host Plant Preference in a Significant Phytopathogen Vector, Diaphorina citri.

    Science.gov (United States)

    Stockton, Dara G; Martini, Xavier; Patt, Joseph M; Stelinski, Lukasz L

    2016-01-01

    Although specialist herbivorous insects are guided by innate responses to host plant cues, host plant preference may be influenced by experience and is not dictated by instinct alone. The effect of learning on host plant preference was examined in the Asian citrus psyllid, Diaphorina citri; vector of the causal agent of citrus greening disease or huanglongbing. We investigated: a) whether development on specific host plant species influenced host plant preference in mature D. citri; and b) the extent of associative learning in D. citri in the form of simple and compound conditioning. Learning was measured by cue selection in a 2-choice behavioral assay and compared to naïve controls. Our results showed that learned responses in D. citri are complex and diverse. The developmental host plant species influenced adult host plant preference, with female psyllids preferring the species on which they were reared. However, such preferences were subject to change with the introduction of an alternative host plant within 24-48 hrs, indicating a large degree of experience-dependent response plasticity. Additionally, learning occurred for multiple sensory modalities where novel olfactory and visual environmental cues were associated with the host plant. However, males and females displayed differing discriminatory abilities. In compound conditioning tasks, males exhibited recognition of a compound stimulus alone while females were capable of learning the individual components. These findings suggest D. citri are dynamic animals that demonstrate host plant preference based on developmental and adult experience and can learn to recognize olfactory and visual host plant stimuli in ways that may be sex specific. These experience-based associations are likely used by adults to locate and select suitable host plants for feeding and reproduction and may suggest the need for more tailored lures and traps, which reflect region-specific cultivars or predominate Rutaceae in the area

  7. Pengaruh Jenis Mangsa dan Suhu pada Perkembangan Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae dan Peranannya dalam Pengendalian Diaphorina citri Kuwayama (Hemiptera: Psyllidae

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    Tris Haris Ramadhan

    2008-07-01

    Full Text Available Diaphorina citri Kuwayama (Hemiptera: Psyllidae is the vector of citrus greening (Huanglongbing bacterium and the most serious impediment to citrus culture. Classical biological control of this psyllid vector should contribute to suppress their population. This research was conducted to determine the performance of Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae when they were fed with D. citri. The larval performance index of M. sexmaculatus on D. citri compared with Aphis craccivora Koch (Hemiptera: Aphididae diet was 1.3.M. sexmaculatus fed with D. citri had lower fitness than those fed with A. craccivora as shown by longer larval stadium, lower adult dry weight, less number of egg produced and lower percentage of egg hatched. M. sexmaculatus grew best at the temperature of 27oC. Employing the exclusion procedure under field condition,M. sexmaculatus could reduce the population of D. citri up to 90%. These findings showed that theM. sexmaculatus could be a potential predator in reducing D. citri, particularly when the more preferred prey A. craccivora was not present.   Diaphorina citri Kuwayama (Hemiptera: Psyllidae merupakan kelompok Psyllid yang menularkan penyebab penyakit Huanglongbing yang sangat berbahaya pada tanaman jeruk. Pengendalian hayati klasik telah banyak memberikan kontribusi dalam pengendalian di lapangan. Penelitian ini dilakukan untuk melihat penampilan Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae dengan pakan D. citri. Indeks penampilan larva M. sexmaculatus dengan pakan D. citri dibandingkan dengan Aphis craccivora Koch (Hemiptera: Aphididae adalah 1,3. M. sexmaculatus yang diberi pakan D. citri menunjukkan penurunan kebugaran dibandingkan jika diberi pakan A. craccivora seperti yang ditunjukkan dengan stadium larva lebih lama, penurunan berat kering serangga dewasa, telur yang dihasilkan lebih sedikit, dan penurunan jumlah telur yang menetas. Menggunakan metode eksklusi pada kondisi

  8. Susceptibility of Diaphorina citri (Hemiptera: Liviidae) and Its Parasitoid Tamarixia radiata (Hymenoptera: Eulophidae) to Entomopathogenic Fungi under Laboratory Conditions.

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    Ibarra-Cortés, K H; Guzmán-Franco, A W; González-Hernández, H; Ortega-Arenas, L D; Villanueva-Jiménez, J A; Robles-Bermúdez, A

    2018-02-01

    Diaphorina citri (Kuwayama) is a global pest of citrus that transmits the bacteria associated with the disease, Huanglongbing. Entomopathogenic fungi and the parasitoid Tamarixia radiata (Waterston) are important biological control agents of this pest and likely to interact in D. citri populations. As a basis for interaction studies, we determined the susceptibility of nymphs and adults of D. citri and adults of the parasitoid T. radiata to six fungal isolates from the species Beauveria bassiana s.l. (Bals.-Criv.) Vuill. (isolates B1 and B3), Metarhizium anisopliae s.s. (Metsch.) (Ma129 and Ma65) and Isaria fumosorosea Wize (I2 and Pae). We conducted experiments evaluating infection levels in all three insect groups following inoculation with a series of conidial concentrations (1 × 10 4 -1 × 10 8 conidia mL -1 ). Results showed that D. citri nymphs and T. radiata were more susceptible to fungal isolates than D. citri adults. Overall, B. bassiana and M. anisopliae isolates caused the greatest infection compared with I. fumosorosea isolates in all three groups of insects. Isolates B1 (B. bassiana) and Ma129 (M. anisopliae) infected a greater proportion of adults and nymphs of D. citri, respectively. Both isolates of B. bassiana caused greater infection in T. radiata compared with isolates of the other fungal species. We propose that isolates B1 and Ma129 are the strongest candidates for control of D. citri. Our results represent the first report of entomopathogenic fungi infecting T. radiata, and the basis for future studies to design a biological control programme that uses both agents more efficiently against D. citri populations.

  9. Diverse Array of New Viral Sequences Identified in Worldwide Populations of the Asian Citrus Psyllid (Diaphorina citri) Using Viral Metagenomics.

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    Nouri, Shahideh; Salem, Nidá; Nigg, Jared C; Falk, Bryce W

    2015-12-16

    The Asian citrus psyllid, Diaphorina citri, is the natural vector of the causal agent of Huanglongbing (HLB), or citrus greening disease. Together; HLB and D. citri represent a major threat to world citrus production. As there is no cure for HLB, insect vector management is considered one strategy to help control the disease, and D. citri viruses might be useful. In this study, we used a metagenomic approach to analyze viral sequences associated with the global population of D. citri. By sequencing small RNAs and the transcriptome coupled with bioinformatics analysis, we showed that the virus-like sequences of D. citri are diverse. We identified novel viral sequences belonging to the picornavirus superfamily, the Reoviridae, Parvoviridae, and Bunyaviridae families, and an unclassified positive-sense single-stranded RNA virus. Moreover, a Wolbachia prophage-related sequence was identified. This is the first comprehensive survey to assess the viral community from worldwide populations of an agricultural insect pest. Our results provide valuable information on new putative viruses, some of which may have the potential to be used as biocontrol agents. Insects have the most species of all animals, and are hosts to, and vectors of, a great variety of known and unknown viruses. Some of these most likely have the potential to be important fundamental and/or practical resources. In this study, we used high-throughput next-generation sequencing (NGS) technology and bioinformatics analysis to identify putative viruses associated with Diaphorina citri, the Asian citrus psyllid. D. citri is the vector of the bacterium causing Huanglongbing (HLB), currently the most serious threat to citrus worldwide. Here, we report several novel viral sequences associated with D. citri. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  10. Survey of endosymbionts in the Diaphorina citri metagenome and assembly of a Wolbachia wDi draft genome.

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    Surya Saha

    Full Text Available Diaphorina citri (Hemiptera: Psyllidae, the Asian citrus psyllid, is the insect vector of Ca. Liberibacter asiaticus, the causal agent of citrus greening disease. Sequencing of the D. citri metagenome has been initiated to gain better understanding of the biology of this organism and the potential roles of its bacterial endosymbionts. To corroborate candidate endosymbionts previously identified by rDNA amplification, raw reads from the D. citri metagenome sequence were mapped to reference genome sequences. Results of the read mapping provided the most support for Wolbachia and an enteric bacterium most similar to Salmonella. Wolbachia-derived reads were extracted using the complete genome sequences for four Wolbachia strains. Reads were assembled into a draft genome sequence, and the annotation assessed for the presence of features potentially involved in host interaction. Genome alignment with the complete sequences reveals membership of Wolbachia wDi in supergroup B, further supported by phylogenetic analysis of FtsZ. FtsZ and Wsp phylogenies additionally indicate that the Wolbachia strain in the Florida D. citri isolate falls into a sub-clade of supergroup B, distinct from Wolbachia present in Chinese D. citri isolates, supporting the hypothesis that the D. citri introduced into Florida did not originate from China.

  11. One Target, Two Mechanisms: The Impact of 'Candidatus Liberibacter asiaticus' and Its Vector, Diaphorina citri, on Citrus Leaf Pigments.

    Science.gov (United States)

    Killiny, Nabil; Nehela, Yasser

    2017-07-01

    Huanglongbing (HLB) is currently the largest threat to global citrus production. We examined the effect of HLB pathogen 'Candidatus Liberibacter asiaticus' infection or infestation by its vector, Diaphorina citri, on 'Valencia' sweet orange leaf pigments using high-performance liquid chromatography, followed by gene expression analysis for 46 involved genes in carotenoid and chlorophyll biosynthesis pathways. Both 'Ca. L. asiaticus' and D. citri alter the total citrus leaf pigment balance with a greater impact by 'Ca. L. asiaticus'. Although zeaxanthin was accumulated in 'Ca. L. asiaticus'-infected leaves, chlorophyllide a was increased in D. citri-infested plants. Our findings support the idea that both 'Ca. L. asiaticus' and D. citri affect the citrus pigments and promote symptom development but using two different mechanisms. 'Ca. L. asiaticus' promotes chlorophyll degradation but accelerates the biosynthesis of carotenoid pigments, resulting in accumulation of abscisic acid and its precursor, zeaxanthin. Zeaxanthin also has a photoprotective role. By contrast, D. citri induced the degradation of most carotenoids and accelerated chlorophyll biosynthesis, leading to chlorophyllide a accumulation. Chlorophyllide a might have an antiherbivory role. Accordingly, we suggest that citrus plants try to defend themselves against 'Ca. L. asiaticus' or D. citri using multifaceted defense systems, based on the stressor type. These findings will help in better understanding the tritrophic interactions among plant, pathogen, and vector.

  12. Survey of endosymbionts in the Diaphorina citri metagenome and assembly of a Wolbachia wDi draft genome.

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    Saha, Surya; Hunter, Wayne B; Reese, Justin; Morgan, J Kent; Marutani-Hert, Mizuri; Huang, Hong; Lindeberg, Magdalen

    2012-01-01

    Diaphorina citri (Hemiptera: Psyllidae), the Asian citrus psyllid, is the insect vector of Ca. Liberibacter asiaticus, the causal agent of citrus greening disease. Sequencing of the D. citri metagenome has been initiated to gain better understanding of the biology of this organism and the potential roles of its bacterial endosymbionts. To corroborate candidate endosymbionts previously identified by rDNA amplification, raw reads from the D. citri metagenome sequence were mapped to reference genome sequences. Results of the read mapping provided the most support for Wolbachia and an enteric bacterium most similar to Salmonella. Wolbachia-derived reads were extracted using the complete genome sequences for four Wolbachia strains. Reads were assembled into a draft genome sequence, and the annotation assessed for the presence of features potentially involved in host interaction. Genome alignment with the complete sequences reveals membership of Wolbachia wDi in supergroup B, further supported by phylogenetic analysis of FtsZ. FtsZ and Wsp phylogenies additionally indicate that the Wolbachia strain in the Florida D. citri isolate falls into a sub-clade of supergroup B, distinct from Wolbachia present in Chinese D. citri isolates, supporting the hypothesis that the D. citri introduced into Florida did not originate from China.

  13. Better Together: Association With 'Candidatus Liberibacter Asiaticus' Increases the Reproductive Fitness of Its Insect Vector, Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Pelz-Stelinski, K S; Killiny, N

    2016-05-01

    The duration of the evolutionary association between a pathogen and vector can be inferred based on the strength of their mutualistic interactions. A well-adapted pathogen is likely to confer some benefit or, at a minimum, exhibit low pathogenicity toward its host vector. Coevolution of the two toward a mutually beneficial association appears to have occurred between the citrus greening disease pathogen, Candidatus Liberibacter asiaticus (Las), and its insect vector, the Asian citrus psyllid, Diaphorina citri (Kuwayama). To better understand the dynamics facilitating transmission, we evaluated the effects of Las infection on the fitness of its vector. Diaphorina citri harboring Las were more fecund than their uninfected counterparts; however, their nymphal development rate and adult survival were comparatively reduced. The finite rate of population increase and net reproductive rate were both greater among Las-infected D. citri as compared with uninfected counterparts, indicating that overall population fitness of infected psyllids was improved given the greater number of offspring produced. Previous reports of transovarial transmission, in conjunction with increased fecundity and population growth rates of Las-positive D. citri found in the current investigation, suggest a long evolutionary relationship between pathogen and vector. The survival of Las-infected adult D. citri was lower compared with uninfected D. citri , which suggests that there may be a fitness trade-off in response to Las infection. A beneficial effect of a plant pathogen on vector fitness may indicate that the pathogen developed a relationship with the insect before secondarily moving to plants.

  14. RNA interference of acetylcholinesterase in the Asian citrus psyllid, Diaphorina citri, increases its susceptibility to carbamate and organophosphate insecticides.

    Science.gov (United States)

    Kishk, Abdelaziz; Hijaz, Faraj; Anber, Helmy A I; AbdEl-Raof, Tsamoh K; El-Sherbeni, AbdEl-Hakeem D; Hamed, Sobhy; Killiny, Nabil

    2017-11-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Lividae) transmits the Candidatus Liberibacter asiaticus, which causes citrus greening disease or Huanglongbing, (HLB). To date, there is no efficient cure for HLB disease and the control of D. citri using insecticides became the most important tools for the management of HLB. However, the extensive use of insecticides could increase D. citri resistance to these insecticides. The objective of this study was to investigate the effect of RNA interference of acetylcholinesterase (AChE) on the mortality and susceptibility of D. citri to the four major insecticides used in Florida. In this study, we used a consensus sequence derived from the two AChE genes and cholinesterase 2-like (ChE-2-like) gene to target all of the three genes. Treatment with dsRNA-AChE increased the mortality percentages of both nymphs and adults of D. citri. The mortality percentage increased with the increase in the concentration of applied dsRNA-AChE, and the highest mortality (> 60%) was observed at the highest applied concentration (125ng/μl). Treatments of nymphs or adults with dsRNA-AChE down-regulated the expression of the three targeted genes of D. citri. Silencing of AChE and ChE in D. citri nymphs increased the susceptibility of emerged adults to chlorpyrifos and carbaryl, which act as AChE inhibitors. However, treatment with dsRNA-AChE did not increase the susceptibility of emerged adults to imidacloprid, which acts as an agonist of nicotinic acetylcholine receptors. In the same manner, treatment of adults with dsRNA-AChE increased their susceptibility to chlorpyrifos and carbaryl, but did not affect their susceptibility to imidacloprid. The ANOVA did not show any significant increase in susceptibility of D. citri adults to fenpropathrin after treatment with dsRNA-AChE, either as nymphs or as adults. However, simple linear regression showed that treatment with dsRNA-AChE increased D. citri susceptibility to fenpropathrin

  15. [Identification of two varieties of Citri Fructus by fingerprint and chemometrics].

    Science.gov (United States)

    Su, Jing-hua; Zhang, Chao; Sun, Lei; Gu, Bing-ren; Ma, Shuang-cheng

    2015-06-01

    Citri Fructus identification by fingerprint and chemometrics was investigated in this paper. Twenty-three Citri Fructus samples were collected which referred to two varieties as Cirtus wilsonii and C. medica recorded in Chinese Pharmacopoeia. HPLC chromatograms were obtained. The components were partly identified by reference substances, and then common pattern was established for chemometrics analysis. Similarity analysis, principal component analysis (PCA) , partial least squares-discriminant analysis (PLS-DA) and hierarchical cluster analysis heatmap were applied. The results indicated that C. wilsonii and C. medica could be ideally classified with common pattern contained twenty-five characteristic peaks. Besides, preliminary pattern recognition had verified the chemometrics analytical results. Absolute peak area (APA) was used for relevant quantitative analysis, results showed the differences between two varieties and it was valuable for further quality control as selection of characteristic components.

  16. Diaphorina citri (Kuwayama, 1907 and Tamarixia radiata (Waterson, 1922 in citrus crops of Cundinamarca, Colombia

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    Ebratt Ravelo Everth Emilio

    2011-12-01

    Full Text Available

    The presence of Diaphorina citri Kuwayama (Hemiptera: Psyllidae and Tamarixia radiata (Waterston (Hymenoptera: Eulophidae was recorded in citrus crops of Cundinamarca, Colombia. This work is to know the geographic distribution of D. citri and an initial record of the parasitoid T. radiata in citrus producing areas of this department.

  17. The Scintillation and Tomography Receiver in Space (CITRIS) Instrument for Ionospheric Research

    Science.gov (United States)

    2008-01-01

    be used by data assimila- tion models to improve ionospheric density specifica- tions. Current assimilation models have been devel- oped to...geomagnetic latitude where the layer tends to be higher than at mid - latitudes . The west layer is near a mid - latitude region at –35° geomagnetic...CITRIS relative to the CERTO radio beacon transmitter on the COSMIC FM5 satellite. The orbits cross at a latitude of –35.5° N and a longitude of

  18. Structural and functional analyses of the putrescine binding protein PotF from Xanthomonas citri

    Energy Technology Data Exchange (ETDEWEB)

    Santana, L.D.F.; Balan, A. [Laboratorio Nacional de Biociencias - LNBIO, Campinas, SP (Brazil)

    2012-07-01

    Full text: The focus of our group is to determinate the role of ABC transporters in the physiology and growth of Xanthomonas citri, a phytopathogenic bacteria that infects citrus plants causing significant losses for the economy. One of the ABC transporters identified in the X. citri genome and that was showed to be active during the infection in Citrus sinensis plants was the putrescine transporter. This transporter consists of two internal membrane proteins PotG and PotH that form a pore, a cytoplasmic protein that gives energy for the transport and the periplasmic-binding protein PotF, which is responsible for the affinity and specificity of the system. Its function is associated to the microbial carcinogenesis, biofilm formation, escape from phagolysosomes, bacteriocin production, toxin activity and protection from oxidative and acid stress. In this work, we show for the first time, the expression, purification, functional and structural analyses of the X. citri PotF protein. The PotF was expressed from Escherichia coli cells strain Arctic, as a 40 kDa soluble protein, after induction of IPTG for twenty four hours at thirteen deg C. Using immobilized metal affinity chromatography for purification, the protein was eluted in the fractions with 10-500 mM of imidazole. To test the folding and cability to bind putrescine, spectroscopic analyses were performed using circular dichroism and intrinsic fluorescence. The data showed that PotF suffers conformational changes in presence of ligands and in different pH, suggesting a possible interaction with the tested ligand. Moreover, based on bioinformatics studies and molecular modeling analyses, we showed that X. citri PotF is highly conserved when compared to orthologs present in other bacteria, including the residues that form the ligand-binding site. The production of PotF in a soluble and stable form will allow us to start the crystallization trials in attempt to solve its structure. (author)

  19. Induction of mutations in citrus for the development of resistance to Xanthomonas citri (Hasse) Dowson

    International Nuclear Information System (INIS)

    Zubrzycki, H.M.; Diamante de Zubrzycki, A.

    1982-01-01

    With the aim of obtaining resistance to Xanthomonas citri in citrus, mutagenic treatment was carried out with X-rays and gamma rays on buds and seedlings. As a prerequisite, attempts were made to determine some physiological and structural differences in leaves in order to evaluate and analyse the reaction to the bacterium in qualitative and quantitative terms. Citrus were found to present 3-4 annual sproutings, each having a different intensity. Grapefruit showed a greater initial increase and final length than orange, but lemon growth was greater than all the others. According to their growth, leaves clustered in three groups. Those in the middle part of the sprout showed the greatest daily increase, followed in decreasing order by those of the base and those of the apex. In orange cultivars with different degrees of reaction to Xanthomonas citri a direct association between daily growth of leaves and susceptibility was found. In fully developed leaves the number of stomata per surface unit presented an inverse ratio with susceptibility. It was observed that in a given genotype the stomata frequency per surface unit was higher in young leaves than in developed ones. Also a direct association between the leaf area and the number of stomata per leaf was found. Natural field infections were measured in leaves of developed plants. Infection in each of the 3-4 annual sproutings depends on environmental factors during the growth period and the predisposition period of the leaves. The available variation for reaction to Xanthomonas citri was higher in oranges than in grapefruit. The abscission of each leaf depends on its degree of infection, but the cultivars classed as more resistant are those requiring a smaller affected area to provoke the leaf abscission. However, abscission of a leaf is independent of the fate of the neighbouring ones. The existence of a continuous grading of infection damage within the orange cultivars suggests a genetic component for resistance

  20. Structural and functional analyses of the putrescine binding protein PotF from Xanthomonas citri

    International Nuclear Information System (INIS)

    Santana, L.D.F.; Balan, A.

    2012-01-01

    Full text: The focus of our group is to determinate the role of ABC transporters in the physiology and growth of Xanthomonas citri, a phytopathogenic bacteria that infects citrus plants causing significant losses for the economy. One of the ABC transporters identified in the X. citri genome and that was showed to be active during the infection in Citrus sinensis plants was the putrescine transporter. This transporter consists of two internal membrane proteins PotG and PotH that form a pore, a cytoplasmic protein that gives energy for the transport and the periplasmic-binding protein PotF, which is responsible for the affinity and specificity of the system. Its function is associated to the microbial carcinogenesis, biofilm formation, escape from phagolysosomes, bacteriocin production, toxin activity and protection from oxidative and acid stress. In this work, we show for the first time, the expression, purification, functional and structural analyses of the X. citri PotF protein. The PotF was expressed from Escherichia coli cells strain Arctic, as a 40 kDa soluble protein, after induction of IPTG for twenty four hours at thirteen deg C. Using immobilized metal affinity chromatography for purification, the protein was eluted in the fractions with 10-500 mM of imidazole. To test the folding and cability to bind putrescine, spectroscopic analyses were performed using circular dichroism and intrinsic fluorescence. The data showed that PotF suffers conformational changes in presence of ligands and in different pH, suggesting a possible interaction with the tested ligand. Moreover, based on bioinformatics studies and molecular modeling analyses, we showed that X. citri PotF is highly conserved when compared to orthologs present in other bacteria, including the residues that form the ligand-binding site. The production of PotF in a soluble and stable form will allow us to start the crystallization trials in attempt to solve its structure. (author)

  1. RNA interference of carboxyesterases causes nymph mortality in the Asian citrus psyllid, Diaphorina citri.

    Science.gov (United States)

    Kishk, Abdelaziz; Anber, Helmy A I; AbdEl-Raof, Tsamoh K; El-Sherbeni, AbdEl-Hakeem D; Hamed, Sobhy; Gowda, Siddarame; Killiny, Nabil

    2017-03-01

    Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important pest of citrus. In addition, D. citri is the vector of Huanglongbing, a destructive disease in citrus, also known as citrus greening disease caused by Candidatus Liberibacter asiaticus. Huanglongbing causes huge losses for citrus industries. Insecticide application for D. citri is the major strategy to prevent disease spread. The heavy use of insecticides causes development of insecticide resistance. We used RNA interference (RNAi) to silence genes implicated in pesticide resistance in order to increase the susceptibility. The activity of dsRNA to reduce the expression of carboxyesterases including esterases FE4 (EstFE4) and acetylcholinesterases (AChe) in D. citri was investigated. The dsRNA was applied topically to the fourth and fifth instars of nymphs. We targeted several EstFE4 and AChe genes using dsRNA against a consensus sequence for each of them. Five concentrations (25, 50, 75, 100, 125 ng/μl) from both dsRNAs were used. The treatments with the dsRNA caused concentration dependent nymph mortality. The highest gene expression levels of both AChe and EstFE4 were found in the fourth and fifth nymphal instars. Gene expression analysis showed that AChe genes were downregulated in emerged adults from dsRNA-AChe-treated nymphs compared to controls. However, EstFE4 genes were not affected. In the same manner, treatment with dsRNA-EstFE4 reduced expression level of EstFE4 genes in emerged adults from treated nymphs, but did not affect the expression of AChe genes. In the era of environmentally friendly control strategies, RNAi is a new promising venue to reduce pesticide applications. © 2017 Wiley Periodicals, Inc.

  2. Biology of the Huanglongbing vector Diaphorina citri (Hemiptera: Liviidae) on different host plants.

    Science.gov (United States)

    Alves, G R; Diniz, A J F; Parra, J R P

    2014-04-01

    Although many studies have been conducted on the development and reproductive potential of Diaphorina citri Kuwayama, 1908 (Hemiptera: Liviidae) in different host species, few have evaluated these parameters on different varieties of the same host species. This study evaluated the influence of five commercial varieties of citrus (Citrus spp. L.)--Hamlin, Natal, Pêra, Ponkan, and Valencia-and orange jasmine [Murraya exotica (L.) Jack] on the development of D. citri. Survival rates for the egg stage were highest on orange jasmine (85.7%) and on Valencia (83.3%). The lowest viability of the nymphal stage was also observed on Hamlin, averaging 57.4%. Values for total viability ranged from 65.9 to 32.6%, and were highest on Valencia. The longest egg-adult development time was on Natal, with a mean of 18.4 d; the shortest total development time was on orange jasmine, with a mean of 17.3 d. Based on the fertility life table, the net reproductive rate (Ro) of D. citri was 2.5 times higher when reared on Valencia than on Hamlin. The other parameters (duration of each generation [T], finite rate of increase [lambda], and innate capacity to increase in number [r(m)]) also demonstrated that Valencia is best suited to this insect. The results obtained for the biological parameters and the fertility life table indicate that Valencia and orange jasmine were the most suitable hosts, whereas Hamlin was least suitable for the development of D. citri. These results provide information for the installation of new citrus groves, especially in the choice of varieties to be planted and the location of different varieties within the groves, with a view toward the management of Huanglongbing or HLB.

  3. Selection of Reference Genes for Expression Studies in Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Bassan, Meire Menezes; Angelotti-Mendonc A, Je Ssika; Alves, Gustavo Rodrigues; Yamamoto, Pedro Takao; Moura O Filho, Francisco de Assis Alves

    2017-12-05

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is considered the main vector of the bacteria associated with huanglongbing, a very serious disease that has threatened the world citrus industry. The absence of efficient control management protocols, including a lack of resistant cultivars, has led to the development of different approaches to study this pathosystem. The production of resistant genotypes relies on D. citri gene expression analyses by RT-qPCR to assess control of the vector population. High-quality, reliable RT-qPCR analyses depend upon proper reference gene selection and validation. However, adequate D. citri reference genes have not yet been identified. In the present study, we evaluated the genes EF 1-α, ACT, GAPDH, RPL7, RPL17, and TUB as candidate reference genes for this insect. Gene expression stability was evaluated using the mathematical algorithms deltaCt, NormFinder, BestKeeper, and geNorm, at five insect developmental stages, grown on two different plant hosts [Citrus sinensis (L.) Osbeck (Sapindales: Rutaceae) and Murraya paniculata (L.) Jack (Sapindales: Rutaceae)]. The final gene ranking was calculated using RefFinder software, and the V-ATPase-A gene was selected for validation. According to our results, two reference genes are recommended when different plant hosts and developmental stages are considered. Considering gene expression studies in D. citri grown on M. paniculata, regardless of the insect developmental stage, GAPDH and RPL7 have the best fit as reference genes in RT-qPCR analyses, whereas GAPDH and EF 1-α are recommended as reference genes in insect studies using C. sinensis. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Whole-Genome Sequence of "Candidatus Profftella armatura" from Diaphorina citri in Guangdong, China.

    Science.gov (United States)

    Wu, F; Deng, X; Liang, G; Huang, J; Cen, Y; Chen, J

    2015-11-05

    The genome of "Candidatus Profftella armatura" strain YCPA from Diaphorina citri in Guangdong, China, was sequenced. The strain has a chromosome of 457,565 bp, 24.3% G+C content, 364 predicted open reading frames (ORFs), and 38 RNAs, and a plasmid, pYCPA54, of 5,458 bp with 23.9% G+C content and 5 ORFs. Copyright © 2015 Wu et al.

  5. Effects of Temperature, Photoperiod, and Rainfall on Morphometric Variation of Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Paris, Thomson M; Allan, Sandra A; Hall, David G; Hentz, Matthew G; Croxton, Scott D; Ainpudi, Niharika; Stansly, Philip A

    2017-02-01

    Phenotypic plasticity provides a mechanism by which an organism can adapt to new or changing environments. Earlier studies have demonstrated the variability of Diaphorina citri Kuwayama (Asian citrus psyllid) population dynamics, but no analysis of morphological changes induced by seasonal or artificial laboratory-induced conditions has yet been documented. Such morphometric variation has been found to correspond in dispersal capabilities in several insect taxa. In this study, the effects of temperature and photoperiod on morphometric variation of D. citri were examined through laboratory rearing of psyllids under controlled temperatures (20 °C, 28 °C, and 30 °C) and under a short photoperiod of 10.5:13.5 (L:D) h and a long photoperiod of 16:8 (L:D) h. Diaphorina citri were field-collected monthly from three citrus groves in Fort Pierce, Gainesville, and Immokalee, FL, to evaluate potential field-associated environmental effects. Both traditional and geometric morphometric data were used to analyze the correlation between environmental and morphometric variation. A strong correlation was found between temperature and shape change, with larger and broader wings at colder temperatures in the laboratory. Short day length resulted in shorter and narrower wings as well. From the field, temperature, rainfall, and photoperiod were moderately associated with shape parameters. Adult D. citri with blue/green abdomens collected in the laboratory and field studies were larger in size and shape than those with brown/gray abdomens. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

  6. Resistance Management for Asian Citrus Psyllid, Diaphorina citri Kuwayama, in Florida

    Directory of Open Access Journals (Sweden)

    Xue Dong Chen

    2017-09-01

    Full Text Available The Asian citrus psyllid, Diaphorina citri Kuwayma, is one of the most important pests in citrus production. The objective of this study was to evaluate D. citri resistance management with three insecticide rotations and compare them with no rotation and an untreated check. The different insecticides (modes of action tested were: dimethoate, imidacloprid, diflubenzuron, abamectin 3% + thiamethoxam 13.9%, and fenpropathrin. Eggs, nymph, and adult psyllids were counted weekly. Five insecticide applications were made in 2016. Insecticide susceptibility was determined by direct comparison with a laboratory susceptible population and field populations before and after all treatments were applied. Rankings of eggs, nymphs, and adults counted in treated plots were significantly lower than in the untreated control plots after each application. Initially, the resistance ratio (RR50 for each rotation model, as compared with laboratory susceptible strain and the field population before application, was less than 5.76 and 4.31, respectively. However, after five applications with dimethoate, the RR50 using the laboratory and pre-treatment field populations was 42.34 and 34.74, respectively. Our results indicate that effectively rotating modes of action can delay and/or prevent development of insecticide resistance in populations of D. citri.

  7. Genetic diversity of Xanthomonas axonopodis pv. citri based on plasmid profile and pulsed field gel electrophoresis

    Directory of Open Access Journals (Sweden)

    Carvalho Flávia Maria de Souza

    2005-01-01

    Full Text Available Xanthomonas axonopodis pv. citri strains that cause disease in citrus were investigated by pulsed field and plasmid profile analysis. For the first method, genomic DNA was digested by the rare-cutting enzymes Xba I and Vsp I. The strains evaluated were collected in seven different States of Brazil and in Argentina, Bolivia, Paraguay and Uruguay. Genetic variability was found among strains of X. axonopodis pv. citri from different geographical areas Argentina, Bolivia and Uruguay, with similarities varying from 0.62 to 0.83. However, the strains collected in Brazil, despite being from different States, have shown a genetic similarity ranging from 0.83 to 1.00. Cluster analysis showed a relationship between genomic similarity and geographical origin of the strains. Plasmids were observed in all strains, with a total of five different plasmids, with sizes between 57.7 and 83.0 kilobases. The 72.6 kb plasmid was the most frequent, present in 15 out of 22 strains, while the 68.1 kb plasmid was observed in two strains only. Although the plasmid diversity detected in the present study was not very great, the X. axonopodis pv. citri strains evaluated showed a considerable degree of diversity with regard to this extrachromosomal genetic element.

  8. Pengaruh Minyak Atsiri Asal Kulit Jeruk Manis dan Besar terhadap Perkembangan Tungau Panonychus citri (Acarina: Tetranychidae

    Directory of Open Access Journals (Sweden)

    Mizu lstianto

    2003-12-01

    Full Text Available P. citri (Acarina: Tetranychidae is one of the economically important citrus pests in Indonesia. However, the association of this pest with its host is not well understood. The objective of this research was to evaluate the effects of essential oil extracted from sweet orange and pumello fruit peels on the development of P. citri. The research was conducted in the laboratory of IP2TP Tlekung Malang, using a complete random design consisted of six treatments. Fifteen mites were used for each treatment. The treatments were concentrations 10, 20, 40, and 80 ppm of essential oil. Parafin was used as a positive control because it was a diluting solution for the essential oil. The control received no application. The result showed that the main content of essential oil extracted from sweet orange and pumello was limonene. The essential oils prolonged the life cycle and reduced the fecundity of P. citri. The effects of essential oil extracted from pumello were found to be more pronounced than were from sweet orange. These differences might be due to the differences in the composition of the volatile compounds other than limonene.

  9. Effects of different temperature regimes on survival of Diaphorina citri and its endosymbiotic bacterial communities.

    Science.gov (United States)

    Hussain, Mubasher; Akutse, Komivi Senyo; Ravindran, Keppanan; Lin, Yongwen; Bamisile, Bamisope Steve; Qasim, Muhammad; Dash, Chandra Kanta; Wang, Liande

    2017-09-01

    The Asian citrus psyllid, Diaphorina citri, is a major pest of citrus and vector of citrus greening (huanglongbing) in Asian. In our field-collected psyllid samples, we discovered that Fuzhou (China) and Faisalabad (Pakistan), populations harbored an obligate primary endosymbiont Candidatus Carsonella (gen. nov.) with a single species, Candidatus Carsonella ruddii (sp. nov.) and a secondary endosymbiont, Wolbachia surface proteins (WSP) which are intracellular endosymbionts residing in the bacteriomes. Responses of these symbionts to different temperatures were examined and their host survival assessed. Diagnostic PCR assays showed that the endosymbionts infection rates were not significantly reduced in both D. citri populations after 24 h exposure to cold or heat treatments. Although quantitative PCR assays showed significant reduction of WSP relative densities at 40°C for 24 h, a substantial decrease occurred as the exposure duration increased beyond 3 days. Under the same temperature regimes, Ca. C. ruddii density was initially less affected during the first exposure day, but rapidly reduced at 3-5 days compared to WSP. However, the mortality of the psyllids increased rapidly as exposure time to heat treatment increased. The responses of the two symbionts to unfavorable temperature regimes highlight the complex host-symbionts interactions between D. citri and its associated endosymbionts. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  10. Resistance Management for Asian Citrus Psyllid, Diaphorina citri Kuwayama, in Florida.

    Science.gov (United States)

    Chen, Xue Dong; Stelinski, Lukasz L

    2017-09-20

    The Asian citrus psyllid, Diaphorina citri Kuwayma, is one of the most important pests in citrus production. The objective of this study was to evaluate D. citri resistance management with three insecticide rotations and compare them with no rotation and an untreated check. The different insecticides (modes of action) tested were: dimethoate, imidacloprid, diflubenzuron, abamectin 3% + thiamethoxam 13.9%, and fenpropathrin. Eggs, nymph, and adult psyllids were counted weekly. Five insecticide applications were made in 2016. Insecticide susceptibility was determined by direct comparison with a laboratory susceptible population and field populations before and after all treatments were applied. Rankings of eggs, nymphs, and adults counted in treated plots were significantly lower than in the untreated control plots after each application. Initially, the resistance ratio (RR 50 ) for each rotation model, as compared with laboratory susceptible strain and the field population before application, was less than 5.76 and 4.31, respectively. However, after five applications with dimethoate, the RR 50 using the laboratory and pre-treatment field populations was 42.34 and 34.74, respectively. Our results indicate that effectively rotating modes of action can delay and/or prevent development of insecticide resistance in populations of D. citri .

  11. Efficacy of essential oil of Piper aduncum against nymphs and adults of Diaphorina citri.

    Science.gov (United States)

    Volpe, Haroldo Xl; Fazolin, Murilo; Garcia, Rafael B; Magnani, Rodrigo F; Barbosa, José Carlos; Miranda, Marcelo P

    2016-06-01

    Insecticide application is the main way to control Diaphorina citri. However, it causes environmental contamination, has a negative impact on beneficial organisms and leads to psyllid resistance. The essential oil of Piper aduncum has low toxicity towards the environment and contains dillapiol, which has proven to be effective against several crop pests. Here, we studied its efficacy against nymphs and adults of D. citri under laboratory conditions. Oils with three concentrations of dillapiol (69.3, 79.9 and 85.4%) at 0.5, 0.75 and 1.0% dilutions plus 0.025% adjuvant were tested. All treatments caused 90-100% mortality in nymphs. Topical treatments with oil containing 79.9 and 85.4% dillapiol at 0.75% and 1% dilutions were effective (mortality ≥80%) in adults. However, the essential oil showed no residual activity against adults (mortality ≤30%). Dillapiol-rich oil is a promising compound for D. citri control. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  12. Latency and Persistence of 'Candidatus Liberibacter asiaticus' in Its Psyllid Vector, Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Canale, Maria Cristina; Tomaseto, Arthur Fernando; Haddad, Marineia de Lara; Della Coletta-Filho, Helvécio; Lopes, João Roberto Spotti

    2017-03-01

    Although 'Candidatus Liberibacter asiaticus' (Las) is a major pathogen associated with citrus huanglongbing (HLB), some characteristics of transmission by the psyllid vector Diaphorina citri are not fully understood. We examined the latent period and persistence of transmission of Las by D. citri in a series of experiments at 25°C, in which third-instar psyllid nymphs and 1-week-old adults were confined on infected citrus for an acquisition access period (AAP), and submitted to sequential inoculation access periods (IAPs) on healthy citrus seedlings. The median latent period (LP 50 , i.e., acquisition time after which 50% of the individuals can inoculate) of 16.8 and 17.8 days for psyllids that acquired Las as nymphs and adults, respectively, was determined by transferring single individuals in 48-h IAPs. Inoculation events were intermittent and randomly distributed over the IAPs, but were more frequent after acquisition by nymphs. A minimum latent period of 7 to 10 days was observed by transferring groups of 10 psyllids in 48-h IAPs, after a 96-h AAP by nymphs. Psyllids transmitted for up to 5 weeks, when submitted to sequential 1-week IAPs after a 14-day AAP as nymphs. The long latent period and persistence of transmission are indirect evidences of circulative propagation of Las in D. citri.

  13. The molybdate-binding protein (ModA) of the plant pathogen Xanthomonas axonopodis pv. citri.

    Science.gov (United States)

    Balan, Andrea; Santacruz, Carolina P; Moutran, Alexandre; Ferreira, Rita C C; Medrano, Francisco J; Pérez, Carlos A; Ramos, Carlos H I; Ferreira, Luís C S

    2006-12-01

    The modABC operon of phytopathogen Xanthomonas axonopodis pv. citri (X. citri) encodes a putative ABC transporter involved in the uptake of the molybdate and tungstate anions. Sequence analyses showed high similarity values of ModA orthologs found in X. campestris pv. campestris (X. campestris) and Escherichia coli. The X. citri modA gene was cloned in pET28a and the recombinant protein, expressed in the E. coli BL21 (DE3) strain, purified by immobilized metal affinity chromatography. The purified protein remained soluble and specifically bound molybdate and tungstate with K(d) 0.29+/-0.12 microM and 0.58+/-0.14 microM, respectively. Additionally binding of molybdate drastically enhanced the thermal stability of the recombinant ModA as compared to the apoprotein. This is the first characterization of a ModA ortholog expressed by a phytopathogen and represents an important tool for functional, biochemical and structural analyses of molybdate transport in Xanthomonas species.

  14. A Xanthomonas citri subsp citri hypothetical protein related to virulence contains a non-functional HD domain and is implicated in flagellar motility.

    Science.gov (United States)

    Vieira, F C F; Gonçalves, A M; Mendoza, E F R; Ferreira, R M; Costa, M L M; Balbuena, T S; Sebinelli, H G; Ciancaglini, P; Pizauro Junior, J M; Ferro, J A

    2017-08-31

    Citrus canker, caused by the Gram-negative bacterium Xanthomonas citri subsp citri (Xac), severely affects most economically important citrus varieties worldwide. A previous study showed that disruption of the ORF XAC1201 from the Xac 306 strain by transposon Tn5 decreased bacterium virulence in the Rangpur lime host (Citrus limonia L. Osbeck). However, little is known regarding the possible function of the hypothetical protein XAC1201 and how it affects the virulence of Xac 306. Here, we confirmed that disruption of ORF XAC1201 reduces Xac 306 virulence in two different hosts, delaying the onset of typical symptoms. In silico analysis suggested that XAC1201 interacts with the flagellar proteins FliM and FliL, known to be an important factor for virulence. In fact, motility assays revealed that the XAC1201 mutant has a significant difference in motility compared to the wild-type Xac 306. Also, a 3-D structure model revealed modified cofactor binding sites and suggested that XAC1201 has a non-functional HD domain. This hypothesis was confirmed by enzymatic assays performed in purified, XAC1201 recombinant protein expressed in Escherichia coli, which revealed no significant activities previously associated with HD domains for the tested substrates. Thus, the role of the XAC1201 protein in Xac 306 virulence seems to be related to flagellar motility, although a non-classic role for the HD domain cannot be dismissed.

  15. The effects of host, geographic origin, and gender on the thermal requirements of Diaphorina citri (Hemiptera: Psyllidae).

    Science.gov (United States)

    Nava, Dori E; Gomez-Torres, Mariuxi L; Rodrigues, Marjorie D; Bento, José M S; Haddad, Marinéia L; Parra, José R P

    2010-04-01

    Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is the vector of the bacteria that causes citrus greening and is considered one of the world's most important citrus diseases. We examined how host, geographic region, and gender affect the thermal requirements of D. citri. The insects were reared in climatic chambers at constant temperatures of 18, 20, 22, 25, 28, 30, and 32 +/- 1 degrees C, 70 +/- 10% RH, and a 14 h photophase. Host plants for D. citri included orange (Citrus sinensis [Rutaceae]) varieties Pêra and Natal, the rootstock, Rungpur lime (C. limonia [Rutaceae]) and the natural host, Orange jessamine (Murraya paniculata [Rutaceae]). To study the influence of geographic origin on thermal requirements, we studied D. citri populations from Piracicaba, SP (warmer region) and Itapetininga, SP (cooler region). The duration and survival of the development stages and the duration of the total development (egg-adult) did not differ significantly on the different hosts, but it did vary with temperature. Nymphs of D. citri created on the different hosts have the same thermal requirements. The thermal requirements for this species collected from the two climate regions were identical; males and females also had the same thermal requirements.

  16. Geographic distribution of habitat, development, and population growth rates of the Asian citrus psyllid, Diaphorina citri, in Mexico.

    Science.gov (United States)

    López-Collado, José; Isabel López-Arroyo, J; Robles-García, Pedro L; Márquez-Santos, Magdalena

    2013-01-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is an introduced pest in Mexico and a vector of huanglongbing, a lethal citrus disease. Estimations of the habitat distribution and population growth rates of D. citri are required to establish regional and areawide management strategies and can be used as a pest risk analysis tools. In this study, the habitat distribution of D. citri in Mexico was computed with MaxEnt, an inductive, machine-learning program that uses bioclimatic layers and point location data. Geographic distributions of development and population growth rates were determined by fitting a temperature-dependent, nonlinear model and projecting the rates over the target area, using the annual mean temperature as the predictor variable. The results showed that the most suitable regions for habitat of D. citri comprise the Gulf of Mexico states, Yucatán Peninsula, and areas scattered throughout the Pacific coastal states. Less suitable areas occurred in northern and central states. The most important predictor variables were related to temperature. Development and growth rates had a distribution wider than habitat, reaching some of the northern states of México. Habitat, development, and population growth rates were correlated to each other and with the citrus producing area. These relationships indicated that citrus producing states are within the most suitable regions for the occurrence, development, and population growth of D. citri, therefore increasing the risk of huanglongbing dispersion.

  17. Mites (acari) infesting commensal rats in Suez Canal zone, Egypt.

    Science.gov (United States)

    el Kady, G A; Shoukry, A; Ragheb, D A; el Said, A M; Habib, K S; Morsy, T A

    1995-08-01

    Mites are arthropods distinguished from ticks by usually being microscopical in size and have a hypostome unarmed with tooth-like anchoring processes. They are group in a number of suborders, each with super-families and families including many genera of medical and economic importance. In this paper, commensal rodents (Rattus norvegicus, R. r. alexandrinus and R. r. frugivorous) were surveyed in the Suez Canal Zone for their acari ectoparasites. Four species of mites were recovered. In a descending order of mite indices, they were Eulaelaps stabularis (4.83 on 6 rats), Laelaps nuttalli (3.11 on 27 rats), Ornithonyssus bacoti (1.66 on 9 rats) and Dermanyssus gallinae (0.66 on 24 rats). The overall mite indices in the three governorates were 3.66 in Suez, 2.82 in Ismailia and zero in Port Said. The medical and economic importance of the mites were discussed.

  18. Further studies on South African plants: Acaricidal activity of organic plant extracts against Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

    CSIR Research Space (South Africa)

    Wellington, Kevin W

    2017-01-01

    Full Text Available -1 Veterinary Parasitology, vol. 234: 10-12 Further studies on South African plants: Acaricidal activity of organic plant extracts against Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) Wellington, KW Leboho, T Sakong, BM Adenubi, OT Eloff, JN...

  19. Essential Oil Variation from Twenty Two Genotypes of Citrus in Brazil-Chemometric Approach and Repellency Against Diaphorina citri Kuwayama.

    Science.gov (United States)

    Andrade, Moacir Dos Santos; Ribeiro, Leandro do Prado; Borgoni, Paulo Cesar; Silva, Maria Fátima das Graças Fernandes da; Forim, Moacir Rossi; Fernandes, João Batista; Vieira, Paulo Cezar; Vendramin, José Djair; Machado, Marcos Antônio

    2016-06-22

    The chemical composition of volatile oils from 22 genotypes of Citrus and related genera was poorly differentiated, but chemometric techniques have clarified the relationships between the 22 genotypes, and allowed us to understand their resistance to D. citri. The most convincing similarities include the synthesis of (Z)-β-ocimene and (E)-caryophyllene for all 11 genotypes of group A. Genotypes of group B are not uniformly characterized by essential oil compounds. When stimulated with odor sources of 22 genotypes in a Y-tube olfactometer D. citri preferentially entered the arm containing the volatile oils of Murraya paniculata, confirming orange jasmine as its best host. C. reticulata × C. sinensis was the least preferred genotype, and is characterized by the presence of phytol, (Z)-β-ocimene, and β-elemene, which were not found in the most preferred genotype. We speculate that these three compounds may act as a repellent, making these oils less attractive to D. citri.

  20. Structural and physiological analyses of the alkanesulphonate-binding protein (SsuA of the citrus pathogen Xanthomonas citri.

    Directory of Open Access Journals (Sweden)

    Fabiano Tófoli de Araújo

    Full Text Available BACKGROUND: The uptake of sulphur-containing compounds plays a pivotal role in the physiology of bacteria that live in aerobic soils where organosulfur compounds such as sulphonates and sulphate esters represent more than 95% of the available sulphur. Until now, no information has been available on the uptake of sulphonates by bacterial plant pathogens, particularly those of the Xanthomonas genus, which encompasses several pathogenic species. In the present study, we characterised the alkanesulphonate uptake system (Ssu of Xanthomonas axonopodis pv. citri 306 strain (X. citri, the etiological agent of citrus canker. METHODOLOGY/PRINCIPAL FINDINGS: A single operon-like gene cluster (ssuEDACB that encodes both the sulphur uptake system and enzymes involved in desulphurisation was detected in the genomes of X. citri and of the closely related species. We characterised X. citri SsuA protein, a periplasmic alkanesulphonate-binding protein that, together with SsuC and SsuB, defines the alkanesulphonate uptake system. The crystal structure of SsuA bound to MOPS, MES and HEPES, which is herein described for the first time, provides evidence for the importance of a conserved dipole in sulphate group coordination, identifies specific amino acids interacting with the sulphate group and shows the presence of a rather large binding pocket that explains the rather wide range of molecules recognised by the protein. Isolation of an isogenic ssuA-knockout derivative of the X. citri 306 strain showed that disruption of alkanesulphonate uptake affects both xanthan gum production and generation of canker lesions in sweet orange leaves. CONCLUSIONS/SIGNIFICANCE: The present study unravels unique structural and functional features of the X. citri SsuA protein and provides the first experimental evidence that an ABC uptake system affects the virulence of this phytopathogen.

  1. Protein interaction networks at the host-microbe interface in Diaphorina citri, the insect vector of the citrus greening pathogen.

    Science.gov (United States)

    Ramsey, J S; Chavez, J D; Johnson, R; Hosseinzadeh, S; Mahoney, J E; Mohr, J P; Robison, F; Zhong, X; Hall, D G; MacCoss, M; Bruce, J; Cilia, M

    2017-02-01

    The Asian citrus psyllid ( Diaphorina citri) is the insect vector responsible for the worldwide spread of ' Candidatus Liberibacter asiaticus' (CLas), the bacterial pathogen associated with citrus greening disease. Developmental changes in the insect vector impact pathogen transmission, such that D. citri transmission of CLas is more efficient when bacteria are acquired by nymphs when compared with adults. We hypothesize that expression changes in the D. citri immune system and commensal microbiota occur during development and regulate vector competency. In support of this hypothesis, more proteins, with greater fold changes, were differentially expressed in response to CLas in adults when compared with nymphs, including insect proteins involved in bacterial adhesion and immunity. Compared with nymphs, adult insects had a higher titre of CLas and the bacterial endosymbionts Wolbachia, Profftella and Carsonella. All Wolbachia and Profftella proteins differentially expressed between nymphs and adults are upregulated in adults, while most differentially expressed Carsonella proteins are upregulated in nymphs. Discovery of protein interaction networks has broad applicability to the study of host-microbe relationships. Using protein interaction reporter technology, a D. citri haemocyanin protein highly upregulated in response to CLas was found to physically interact with the CLas coenzyme A (CoA) biosynthesis enzyme phosphopantothenoylcysteine synthetase/decarboxylase. CLas pantothenate kinase, which catalyses the rate-limiting step of CoA biosynthesis, was found to interact with a D. citri myosin protein. Two Carsonella enzymes involved in histidine and tryptophan biosynthesis were found to physically interact with D. citri proteins. These co-evolved protein interaction networks at the host-microbe interface are highly specific targets for controlling the insect vector responsible for the spread of citrus greening.

  2. PENDIDIKAN DAN PELATIHAN PENGENDALIAN KUTU LONCAT JERUK (Diaphorina citri Kuwayama SEBAGAI HAMA DAN VEKTOR PENYAKIT CVPD DI DESA TARO, GIANYAR

    Directory of Open Access Journals (Sweden)

    Wijaya I N.

    2012-10-01

    Full Text Available Training on jumping plantlice of citrus (Diaphorina citri Kuw the vector of CVPD (Citrus Vein Phloem Degeneration has been held at Taro village, Gianyar regency on 30st July 2012. The activities aimed to know bioecology of D. citri, the vector of CVPD. The training was attended by 32 participants from local farmer groups of Taro village. The method used in activities were lectures, demontration and practical in the citrus field. All participants participited anthusiastically and hope the have the next intensive traning of the citrus culture.

  3. Primeiro registro de Tetranychus urticae (Acari: Tetranychidae em mudas de teca no Brasil

    Directory of Open Access Journals (Sweden)

    Alexandre dos Santos

    2014-07-01

    Full Text Available O ácaro fitófago Tetranychus urticae (Kock, 1836 (Acari: Tetranychidae foi relatado e suas injúrias caracterizadas pela primeira vez em viveiro de produção mudas de teca (Tectona grandis no Brasil.

  4. New records of Acari from the sub-Antarctic Prince Edward Islands

    NARCIS (Netherlands)

    Marshall, D.J.; Gremmen, N.J.M.; Coetzee, L.; Oconnor, B.M.; Pugh, P.J.A.; Theron, P.D.; Ueckermann, E.A.

    1999-01-01

    Sixty species of Acari are recorded from the sub-Antarctic Marion and Prince Edward Islands (the Prince Edward archipelago). Twenty of the 45 species collected on recent expeditions are new and currently undescribed. Other new taxa include a family of Mesostigmata, four new genera, and the first

  5. Acción inhibitoria de una cepa de Zymomonas mobilis mobilis aislada de caña de azúcar sobre Xanthomonas citri subsp. citri, agente causal de la cancrosis de los cítricos Inhibition of Xanthomonas citri subsp. citri, causal agent of citrus canker, by a strain of Zymomonas mobilis mobilis isolated from sugarcane

    Directory of Open Access Journals (Sweden)

    María E. Romero

    2008-06-01

    Full Text Available Zymomonas mobilis mobilis (Zm produce factores antimicrobianos que actúan sobre un amplio espectro de microorganismos patógenos para el hombre, animales y plantas. Un problema importante a resolver en los tratamientos con antimicrobianos, es el desarrollo de resistencia a compuestos empleados actualmente, no siendo las bacterias fitopatógenas una excepción. En el presente trabajo se realizaron ensayos de antagonismo con células (pruebas de estrías cruzadas y sobrenadantes concentrados (Sc (por difusión en agar preparados a partir de cultivos de Zm (aislada de jugo de caña de azúcar producido en Tucumán, frente a la bacteria causal de la cancrosis: Xanthomonas citri subsp. citri. Se evaluaron aislamientos de Xcc sensibles (Xc y resistentes (Xcr a compuestos a base de cobre. Los resultados obtenidos mostraron que la bacteria testigo fue inhibida totalmente por las células de Zm, ejerciendo un efecto bactericida. En los ensayos de difusión en el agar se observó que tanto Xc, como Xcr fueron sensibles al Sc de Zm. Se sabe, por estudios anteriores, que los metabolitos de Zymomonas tienen un efecto deletéreo en la membrana celular de E. coli AB1133, inhibiéndose la respiración de la bacteria inmediatamente de agregado Sc (60 UA. En el presente trabajo se observó el mismo efecto, inhibición total de la respiración en Xc, luego del agregado del Sc (60 UA. Por lo observado, se deduce que el blanco de acción de los metabolitos antimicrobianos de Sc en Xc, sería el mismo que el de E. coli AB1133. Con los resultados obtenidos se considera de interés encarar el estudio de los compuestos de Zm para ser empleados en el control de enfermedades que afectan los cultivos de valor económico de la región, como es el caso de la cancrosis, como así también profundizar acerca de la acción de dichos metabolitos en la membrana de Xanthomonas citri subsp. citri.Zymomonas mobilis mobilis (Zm produces antimicrobial factors, which have an effect on

  6. Neonicotinoid-Induced Mortality of Diaphorina Citri (Hemiptera: Liviidae) is Affected by Route of Exposure.

    Science.gov (United States)

    Langdon, Kevin W; Rogers, Michael E

    2017-10-01

    The use of neonicotinoids in citrus (Rutaceae) has increased substantially to help manage the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), a vector of the devastating citrus disease, huanglongbing (HLB). In citrus pest management programs, neonicotinoids are most often applied to the soil as a drench and move through xylem channels from the roots into the foliage. We developed a novel assay to quantify the dose required to kill D. citri following ingestion and compare it with the dose required to kill by contact. The LC50 of the laboratory strain for ingestion of imidacloprid, thiamethoxam, and clothianidin were each approximately 10-fold greater than the respective LC50 by contact exposure. Four field populations were tested to validate comparative exposure of the laboratory strain to imidacloprid and determine the relative susceptibility of field populations to imidacloprid by exposure through ingestion and contact. The contact assay exhibited low (10) RR50 values were observed for the Lake Placid and Lake Alfred populations using the contact and the ingestion method. This research demonstrates that the ingestion assay method described herein is more sensitive in detection of low-level resistance and should be the standard methodology used in monitoring for resistance to systemic insecticides for this global pest. We found D. citri populations with a lower than expected susceptibility to neonicotinoids in the field, which warrants the implementation of resistance management practices to preserve the utility of soil-applied neonicotinoids in citrus. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  7. The dual nature of trehalose in citrus canker disease: a virulence factor for Xanthomonas citri subsp. citri and a trigger for plant defence responses

    KAUST Repository

    Piazza, A.

    2015-03-14

    Xanthomonas citri subsp. citri (Xcc) is a bacterial pathogen that causes citrus canker in susceptible Citrus spp. The Xcc genome contains genes encoding enzymes from three separate pathways of trehalose biosynthesis. Expression of genes encoding trehalose-6-phosphate synthase (otsA) and trehalose phosphatase (otsB) was highly induced during canker development, suggesting that the two-step pathway of trehalose biosynthesis via trehalose-6-phosphate has a function in pathogenesis. This pathway was eliminated from the bacterium by deletion of the otsA gene. The resulting XccΔotsA mutant produced less trehalose than the wild-type strain, was less resistant to salt and oxidative stresses, and was less able to colonize plant tissues. Gene expression and proteomic analyses of infected leaves showed that infection with XccΔotsA triggered only weak defence responses in the plant compared with infection with Xcc, and had less impact on the host plant\\'s metabolism than the wild-type strain. These results suggested that trehalose of bacterial origin, synthesized via the otsA-otsB pathway, in Xcc, plays a role in modifying the host plant\\'s metabolism to its own advantage but is also perceived by the plant as a sign of pathogen attack. Thus, trehalose biosynthesis has both positive and negative consequences for Xcc. On the one hand, it enables this bacterial pathogen to survive in the inhospitable environment of the leaf surface before infection and exploit the host plant\\'s resources after infection, but on the other hand, it is a tell-tale sign of the pathogen\\'s presence that triggers the plant to defend itself against infection. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  8. Comparative proteomic analysis of Xanthomonas citri ssp. citri periplasmic proteins reveals changes in cellular envelope metabolism during in vitro pathogenicity induction.

    Science.gov (United States)

    Artier, Juliana; da Silva Zandonadi, Flávia; de Souza Carvalho, Flávia Maria; Pauletti, Bianca Alves; Leme, Adriana Franco Paes; Carnielli, Carolina Moretto; Selistre-de-Araujo, Heloisa Sobreiro; Bertolini, Maria Célia; Ferro, Jesus Aparecido; Belasque Júnior, José; de Oliveira, Julio Cezar Franco; Novo-Mansur, Maria Teresa Marques

    2018-01-01

    Citrus canker is a plant disease caused by Gram-negative bacteria from the genus Xanthomonas. The most virulent species is Xanthomonas citri ssp. citri (XAC), which attacks a wide range of citrus hosts. Differential proteomic analysis of the periplasm-enriched fraction was performed for XAC cells grown in pathogenicity-inducing (XAM-M) and pathogenicity-non-inducing (nutrient broth) media using two-dimensional electrophoresis combined with liquid chromatography-tandem mass spectrometry. Amongst the 40 proteins identified, transglycosylase was detected in a highly abundant spot in XAC cells grown under inducing condition. Additional up-regulated proteins related to cellular envelope metabolism included glucose-1-phosphate thymidylyltransferase, dTDP-4-dehydrorhamnose-3,5-epimerase and peptidyl-prolyl cis-trans-isomerase. Phosphoglucomutase and superoxide dismutase proteins, known to be involved in pathogenicity in other Xanthomonas species or organisms, were also detected. Western blot and quantitative real-time polymerase chain reaction analyses for transglycosylase and superoxide dismutase confirmed that these proteins were up-regulated under inducing condition, consistent with the proteomic results. Multiple spots for the 60-kDa chaperonin and glyceraldehyde-3-phosphate dehydrogenase were identified, suggesting the presence of post-translational modifications. We propose that substantial alterations in cellular envelope metabolism occur during the XAC infectious process, which are related to several aspects, from defence against reactive oxygen species to exopolysaccharide synthesis. Our results provide new candidates for virulence-related proteins, whose abundance correlates with the induction of pathogenicity and virulence genes, such as hrpD6, hrpG, hrpB7, hpa1 and hrpX. The results present new potential targets against XAC to be investigated in further functional studies. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  9. Chemical composition and fungicidal activity of the essential oil of Thymus vulgaris against Alternaria citri

    Directory of Open Access Journals (Sweden)

    Erica A. Soto Mendívil

    2006-01-01

    Full Text Available Se analizó químicamente el aceite esencial de tomillo (Thymus vulgaris L. por Cromatografía de Gases/Espectroscopia de Masas y se evaluó su actividad fungicida. Los principales constituyentes fueron borneol (28.4%, timol (16.6%, carvacrol metil eter (9.6%, camfeno (6.9%, α-humulene (6.4% y carvacrol (5.0%. Las pruebas de actividad fungicida (in vitro indicaron que la concentración de 1000ppm del aceite esencial de tomillo fue efectivo para inhibir a Alternaria citri, cuando se adicionó al medio de cultivo agar papa dextrosa

  10. Five New Records of Raphignathoid Mites (Acari: Raphignathoidea) from Poland/ Pięć Nowych Gatunków Roztoczy Z Nadrodziny Raphignathoidea (Acari) Stwierdzonych W Faunie Polski

    OpenAIRE

    Doðan Salih; Sevsay Sevgi; Mąkol Joanna; Zeytun Erhan; Buğa Evren

    2014-01-01

    Pięć nowych gatunków roztoczy (Acari: Raphignathoidea) zostało odnoto- wanych jako nowe dla fauny Polski: trzy z rodziny Stigmaeidae, Eustigmaeus rhodomela (Koch), Mediolata obtecta Dónel et Doóan, Stigmaeus glabrisetus Summers, jeden z rodziny Cryptognathidae, Favognathus cucurbita (Berlese), i jeden z rodziny Barbutiidae, Barbuda anguineus (Berlese). Ostatni z wymienio- nych jest jednocześnie pierwszym stwierdzeniem przedstawiciela rodziny Barbutiidae w Polsce.

  11. Five New Records of Raphignathoid Mites (Acari: Raphignathoidea from Poland/ Pięć Nowych Gatunków Roztoczy Z Nadrodziny Raphignathoidea (Acari Stwierdzonych W Faunie Polski

    Directory of Open Access Journals (Sweden)

    Doðan Salih

    2014-12-01

    Full Text Available Pięć nowych gatunków roztoczy (Acari: Raphignathoidea zostało odnoto- wanych jako nowe dla fauny Polski: trzy z rodziny Stigmaeidae, Eustigmaeus rhodomela (Koch, Mediolata obtecta Dónel et Doóan, Stigmaeus glabrisetus Summers, jeden z rodziny Cryptognathidae, Favognathus cucurbita (Berlese, i jeden z rodziny Barbutiidae, Barbuda anguineus (Berlese. Ostatni z wymienio- nych jest jednocześnie pierwszym stwierdzeniem przedstawiciela rodziny Barbutiidae w Polsce.

  12. Effects on Asian Citrus Psyllid (Diaphorina citri Kuwayama) feeding behavior of fenpropathrin and chlorpyrifos within 24 hours of application

    Science.gov (United States)

    Huanglongbing (HLB), also known as citrus greening disease, is one of the most destructive diseases affecting citrus production. The phloem-limited bacterium associated with HLB is transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). One component of HLB managem...

  13. Effects of atmospheric pressure trends on calling, mate-seeking, and phototaxis of Diaphorina citri (Hemiptera: Liviidae)

    Science.gov (United States)

    Insects and other animals sometimes modify behavior in response to changes in atmospheric pressure, an environmental cue that can provide warning of potentially injurious windy and rainy weather. To determine if Diaphorina citri (Hemiptera: Liviidae) calling, mate-seeking, and phototaxis behaviors w...

  14. Xanthomonas citri MinC Oscillates from Pole to Pole to Ensure Proper Cell Division and Shape

    NARCIS (Netherlands)

    Soibelmann Glock Lorenzoni, André; Dantas, Giordanni; Bergsma, Tessa; Ferreira, Henrique; Scheffers, Dirk

    2017-01-01

    Xanthomonas citri (Xac) is the causal agent of citrus canker, a disease that affects citrus crops and causes economic impact worldwide. To further characterize cell division in this plant pathogen, we investigated the role of the protein MinC in cell division, chromosome segregation, and

  15. Using mass spectrometry for identification of ABC transporters from Xanthomonas citri and mutants expressed in different growth conditions

    International Nuclear Information System (INIS)

    Faria, J.N.; Balan, A.; Paes Leme, A.F.

    2012-01-01

    Full text: Xanthomonas citri is a phytopathogenic bacterium that infects citrus plants causing significant losses for the economy. In our group, we have focused on the identification and characterization of ABC transport proteins of this bacterium, in order to determinate their function for growth in vitro and in vivo, during infection. ABC transporters represent one of the largest families of proteins, which transport since small molecules as ions up to oligopeptides and sugars. In prokaryotic cells many works have reported the ABC transport function in pathogenesis, resistance, biofilm formation, infectivity and DNA repair, but until our knowledge, there is no data related to these transporters and X. citri. So, In order to determinate which transporters are expressed in X. citri, we started a proteomic analysis based on mono and bi-dimensional gels associated to mass spectrometry analyses. After growing X. citri and two different mutants deleted for ssuA and nitA genes in LB and minimum media, cellular extracts were obtained and used for preparation of mono and bi-dimensional gels. Seven bands covering the expected mass of ABC transporter components (20 kDa to 50 kDa) in SDS-PAGE were cut off the gel, treated with trypsin and submitted to the MS for protein identification. The results of 2D gels were good enough and will serve as a standard for development of similar experiments in large scale. (author)

  16. Observations on the entomopathogenic fungus Hirsutella citriformis attacking adult Diaphorina citri (Hemiptera: Psyllid) in a managed citrus grove

    Science.gov (United States)

    A two-year field study was conducted in an orange grove (0.7 ha) in Florida to characterize the phenology of the entomopathogen Hirsutella citriformis Speare infecting adults of the Asian citrus psyllid, Diaphorina citri Kuwayama. On the average over the two-year study, 23 percent of adults observed...

  17. Biocuration and improvement of the Diaphorina citri draft genome assembly with long reads, optical maps and long-range scaffolding

    Science.gov (United States)

    The Asian citrus psyllid (Diaphorina citri Kuwayama) is the insect vector of the bacterium Candidatus Liberibacter asiaticus (CLas), the causal agent for the citrus greening or Huanglongbing disease which threatens citrus industry worldwide. This vector is the primary target of approaches to stop th...

  18. β-caryophyllene emitted from a transgenic Arabidopsis or chemical dispenser repels Diaphorina citri, vector of Candidatus Liberibacters

    NARCIS (Netherlands)

    Alquézar, B.; Volpe, H.X.L.; Magnani, R.F.; de Miranda, M.P.; Santos, M.A.; Wulff, N.A.; Bento, J.M.S.; Parra, J.R.P.; Bouwmeester, H.; Peña, L.

    2017-01-01

    Production of citrus, the main fruit tree crop worldwide, is severely threatened by Huanglongbing (HLB), for which as yet a cure is not available. Spread of this bacterial disease in America and Asia is intimately connected with dispersal and feeding of the insect vector Diaphorina citri,

  19. Characterization of the sulfate uptake and assimilation pathway from Xanthomonas citri - targets for bacterial growth inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Tambascia, C.; Balan, A. [Laboratorio Nacional de Biociencias - LNBIO, Campinas, SP (Brazil)

    2012-07-01

    Full text: Microorganisms require sulfur for growth and obtain it either for inorganic sulfate or organosulfur compounds. ATP-Binding Cassete (SulT family) or major facilitator superfamily-type (SulP) transporters are responsible for the sulfate transport into the cell. In Xanthomonas citri, the phytopathogenic bacterium that causes the canker citrus disease, there are no reports related to the importance of these transporters during in vitro or in vivo infection. We identified in X. citri genome all the genes that belong to the well-characterized cys regulon from Escherichia coli and Salmonella typhimurium, which includes three ABC transporters and all the enzymes necessary for sulfate oxide reduction to sulfide and cysteine. Once these genes have been shown to be extremely important for bacteria growth and development in different environments, we chose the sbpcysWUA and cysDNCHIJG operons, which encodes the ABC inorganic sulfate ABC transporter and all the enzymes necessary for conversion of sulfate in cysteine, respectively. As a step for crystallization trials and resolution of their tridimensional structures, the referred genes were amplified and cloned into the cloning vector pGEM T-easy. In addition, using bioinformatics tools and molecular modeling we characterized all the protein functions as well as built tridimensional models of their structure for determination of the active sites. The importance of each protein is discussed aiming the discovery of a good target for development of inhibitors that could block the bacterium growth. (author)

  20. Characterization of the sulfate uptake and assimilation pathway from Xanthomonas citri - targets for bacterial growth inhibitors

    International Nuclear Information System (INIS)

    Tambascia, C.; Balan, A.

    2012-01-01

    Full text: Microorganisms require sulfur for growth and obtain it either for inorganic sulfate or organosulfur compounds. ATP-Binding Cassete (SulT family) or major facilitator superfamily-type (SulP) transporters are responsible for the sulfate transport into the cell. In Xanthomonas citri, the phytopathogenic bacterium that causes the canker citrus disease, there are no reports related to the importance of these transporters during in vitro or in vivo infection. We identified in X. citri genome all the genes that belong to the well-characterized cys regulon from Escherichia coli and Salmonella typhimurium, which includes three ABC transporters and all the enzymes necessary for sulfate oxide reduction to sulfide and cysteine. Once these genes have been shown to be extremely important for bacteria growth and development in different environments, we chose the sbpcysWUA and cysDNCHIJG operons, which encodes the ABC inorganic sulfate ABC transporter and all the enzymes necessary for conversion of sulfate in cysteine, respectively. As a step for crystallization trials and resolution of their tridimensional structures, the referred genes were amplified and cloned into the cloning vector pGEM T-easy. In addition, using bioinformatics tools and molecular modeling we characterized all the protein functions as well as built tridimensional models of their structure for determination of the active sites. The importance of each protein is discussed aiming the discovery of a good target for development of inhibitors that could block the bacterium growth. (author)

  1. 'Candidatus Liberibacter asiaticus' Accumulates inside Endoplasmic Reticulum Associated Vacuoles in the Gut Cells of Diaphorina citri.

    Science.gov (United States)

    Ghanim, Murad; Achor, Diann; Ghosh, Saptarshi; Kontsedalov, Svetlana; Lebedev, Galina; Levy, Amit

    2017-12-05

    Citrus greening disease known also as Huanglongbing (HLB) caused by the phloem-limited bacterium 'Candidatus Liberibacter asiaticus' (CLas) has resulted in tremendous losses and the death of millions of trees worldwide. CLas is transmitted by the Asian citrus psyllid Diaphorina citri. The closely-related bacteria 'Candidatus Liberibacter solanacearum' (CLso), associated with vegetative disorders in carrots, is transmitted by the carrot psyllid Bactericera trigonica. A promising approach to prevent the transmission of these pathogens is to interfere with the vector-pathogen interactions, but our understanding of these processes is limited. It was recently reported that CLas induced changes in the nuclear architecture, and activated programmed cell death, in D. citri midgut cells. Here, we used electron and fluorescent microscopy and show that CLas induces the formation of endoplasmic reticulum (ER)-associated bodies. The bacterium recruits those ER structures into Liberibacter containing vacuoles (LCVs), in which bacterial cells seem to propagate. ER- associated LCV formation was unique to CLas, as we could not detect these bodies in B. trigonica infected with CLso. ER recruitment is hypothesized to generate a safe replicative body to escape cellular immune responses in the insect gut. Understanding the molecular interactions that undelay these responses will open new opportunities for controlling CLas.

  2. Sperm morphology of the leafhopper Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Psylloidea: Liviidae).

    Science.gov (United States)

    Barcellos, Marcelo Silva; Cossolin, Jamile Fernanda Silva; Dias, Glenda; Lino-Neto, José

    2017-08-01

    In this study, by using light and electron microscopy, we describe the sperm morphology of the leafhopper Diaphorina citri, a serious pest of citrus throughout the world. In this species the sperm measures 538.49±8.75μm in length, and as observed in psylloids, the sperm, when manipulated, opens into two filaments, one of which is attached to the nuclear base and the other becomes free. Along the flagellum, and only of it, there are lateral projections, about 2μm in length. Furthermore, at the end of the flagellum three appendages, with approximately 7μm in length, are observed. The head region is formed by the nucleus with compact chromatin, and, parallel to it, a structure of median electron density that extends about 25μm in length ahead of the nuclear tip. The flagellum consists of an axoneme with a 9+9+2 microtubule arrangement, two mitochondrial derivatives, and two accessory bodies each with two regions of different electron density. The presence of lateral projections is a characteristic observed in other Sternorrhyncha. As seen previously, the sperm opening in two filaments, when manipulated, was observed only in Psylloidea, and the presence of the three appendices at the end of the flagellum distinguishes D. citri from the other Psylloidea species studied. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Population dynamics and growth rates of endosymbionts during Diaphorina citri (Hemiptera, Liviidae) ontogeny.

    Science.gov (United States)

    Dossi, Fabio Cleisto Alda; da Silva, Edney Pereira; Cônsoli, Fernando Luis

    2014-11-01

    The infection density of symbionts is among the major parameters to understand their biological effects in host-endosymbionts interactions. Diaphorina citri harbors two bacteriome-associated bacterial endosymbionts (Candidatus Carsonella ruddii and Candidatus Profftella armatura), besides the intracellular reproductive parasite Wolbachia. In this study, the density dynamics of the three endosymbionts associated with the psyllid D. citri was investigated by real-time quantitative PCR (qPCR) at different developmental stages. Bacterial density was estimated by assessing the copy number of the 16S rRNA gene for Carsonella and Profftella, and of the ftsZ gene for Wolbachia. Analysis revealed a continuous growth of the symbionts during host development. Symbiont growth and rate curves were estimated by the Gompertz equation, which indicated a negative correlation between the degree of symbiont-host specialization and the time to achieve the maximum growth rate (t*). Carsonella densities were significantly lower than those of Profftella at all host developmental stages analyzed, even though they both displayed a similar trend. The growth rates of Wolbachia were similar to those of Carsonella, but Wolbachia was not as abundant. Adult males displayed higher symbiont densities than females. However, females showed a much more pronounced increase in symbiont density as they aged if compared to males, regardless of the incorporation of symbionts into female oocytes and egg laying. The increased density of endosymbionts in aged adults differs from the usual decrease observed during host aging in other insect-symbiont systems.

  4. Application of droplet digital PCR for quantitative detection of Spiroplasma citri in comparison with real time PCR.

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    Yogita Maheshwari

    Full Text Available Droplet digital polymerase chain reaction (ddPCR is a method for performing digital PCR that is based on water-oil emulsion droplet technology. It is a unique approach to measure the absolute copy number of nucleic acid targets without the need of external standards. This study evaluated the applicability of ddPCR as a quantitative detection tool for the Spiroplasma citri, causal agent of citrus stubborn disease (CSD in citrus. Two sets of primers, SP1, based on the spiral in housekeeping gene, and a multicopy prophage gene, SpV1 ORF1, were used to evaluate ddPCR in comparison with real time (quantitative PCR (qPCR for S. citri detection in citrus tissues. Standard curve analyses on tenfold dilution series showed that both ddPCR and qPCR exhibited good linearity and efficiency. However, ddPCR had a tenfold greater sensitivity than qPCR and accurately quantified up to one copy of spiralin gene. Receiver operating characteristic analysis indicated that the ddPCR methodology was more robust for diagnosis of CSD and the area under the curve was significantly broader compared to qPCR. Field samples were used to validate ddPCR efficacy and demonstrated that it was equal or better than qPCR to detect S. citri infection in fruit columella due to a higher pathogen titer. The ddPCR assay detected both the S. citri spiralin and the SpV1 ORF1 targets quantitatively with high precision and accuracy compared to qPCR assay. The ddPCR was highly reproducible and repeatable for both the targets and showed higher resilience to PCR inhibitors in citrus tissue extract for the quantification of S. citri compare to qPCR.

  5. Compatibility and Efficacy of Isaria fumosorosea with Horticultural Oils for Mitigation of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae

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    Vivek Kumar

    2017-10-01

    Full Text Available Horticultural oils are an important component of integrated management programs of several phytophagous arthropods and pathogens affecting fruit, ornamentals and vegetables in greenhouse and field production systems. Although effective against the target pest, their incompatibility with biological control agents can compromise efforts to develop eco-friendly management programs for important agricultural pests. In this study, we assessed the in vitro effect of selected refined petroleum oils used in citrus and other horticultural crops with a biopesticide containing the entomopathogenic fungi, Isaria fumosorosea (PFR-97 under laboratory conditions. Further, we used leaf disk bioassays to evaluate the combined efficacy of petroleum oils and I. fumosorosea against the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae, a major pest of citrus in the United States. All five petroleum oil treatments (Orchex, Sun Pure, Conoco Blend -1, Conoco Blend -2, and JMS were compatible with I. fumosorosea blastospores, as none of them were found to affect I. fumosorosea colony-forming units and radial fungal growth measured at 3, 6, 9, and 12 days post-inoculation. All mixed treatments performed better than I. fumosorosea alone against D. citri, where the highest mean survival time of D. citri was 12.5 ± 0.7 days. No significant differences in D. citri survival time and I. fumosorosea growth (fungal development index on dead cadavers, which is important for determining their horizontal transmission, were observed when mixed with Orchex, Sun Pure, Conoco Blend -2, and JMS. Results indicated that horticultural oils in combination with I. fumosorosea could offer citrus growers an alternative treatment for integrating into their current management programs while battling against D. citri in citrus production systems. Due to their eco-friendly, broad-spectrum effect, it could provide control against various citrus pests, while also encouraging the

  6. Evaluation of six different groups of insecticides for the control of citrus psylla Diaphorina citri (Hemiptera: Psyllidae

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    Rakhmin Gul

    2005-01-01

    Full Text Available Studies on the efficacy of different insecticides against citrus psylla, Diaphorina citri (Hemiptera: Psyllidae were carried out at Agricultural Research Institute, Tarnab, Peshawar, Pakistan. Six insecticides viz. Actara 25 WG, (thiamethoxam Cascade 10 DC (Flufenoxuron, Match 050 EC (lufenuron, Thiodan 35 EC (endosulfan, Karate 2.5 EC (α-cyhalothrin, and Supracide 40 EC (methidathion, were tested for their effectiveness against D. citri. After first spray overall mean population of D. citri was 3.63, 4.75, 5.59, 6.66, 7.47, 8.11 per six inches tender shoot on Actara 25 WG, Cascade 10 DC, Match 050 EC, Thiodan 35 EC, Karate 2.5 EC and Supracide 40 EC treated plants respectively, while on control plants the population was 12.39. Similarly, after the second spray of each of the same insecticides the population of D. citri was 2.65, 4.23, 5.61, 6.41, 7.35 and 8.73 respectively. Where in controls there were 15.18 psyllids. Percent decrease of D. citri population in comparison to control after the first spray was highest in Actara 25 WG (72.20 followed by Cascade 10 DC (62.91, Match 050 EC (54.07, Thiodan 35 EC (47.61, Karate 2.5 EC (38.94 and Supracide 40 EC (35.74. After the second spray percent decrease over control recorded was highest in Actara 25 WG (83.54, followed by Cascade 10 DC (71.08, Match 050 EC (63.94, Thiodan 35 EC (60.79, Karate 2.5 EC (52.52 and Supracide 40 EC (45.62.

  7. Compatibility and Efficacy of Isaria fumosorosea with Horticultural Oils for Mitigation of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Kumar, Vivek; Avery, Pasco B; Ahmed, Juthi; Cave, Ronald D; McKenzie, Cindy L; Osborne, Lance S

    2017-10-31

    Horticultural oils are an important component of integrated management programs of several phytophagous arthropods and pathogens affecting fruit, ornamentals and vegetables in greenhouse and field production systems. Although effective against the target pest, their incompatibility with biological control agents can compromise efforts to develop eco-friendly management programs for important agricultural pests. In this study, we assessed the in vitro effect of selected refined petroleum oils used in citrus and other horticultural crops with a biopesticide containing the entomopathogenic fungi, Isaria fumosorosea (PFR-97) under laboratory conditions. Further, we used leaf disk bioassays to evaluate the combined efficacy of petroleum oils and I. fumosorosea against the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), a major pest of citrus in the United States. All five petroleum oil treatments (Orchex, Sun Pure, Conoco Blend -1, Conoco Blend -2, and JMS) were compatible with I. fumosorosea blastospores, as none of them were found to affect I. fumosorosea colony-forming units and radial fungal growth measured at 3, 6, 9, and 12 days post-inoculation. All mixed treatments performed better than I. fumosorosea alone against D. citri , where the highest mean survival time of D. citri was 12.5 ± 0.7 days. No significant differences in D. citri survival time and I. fumosorosea growth (fungal development index) on dead cadavers, which is important for determining their horizontal transmission, were observed when mixed with Orchex, Sun Pure, Conoco Blend -2, and JMS. Results indicated that horticultural oils in combination with I. fumosorosea could offer citrus growers an alternative treatment for integrating into their current management programs while battling against D. citri in citrus production systems. Due to their eco-friendly, broad-spectrum effect, it could provide control against various citrus pests, while also encouraging the retention of effective

  8. Analyses of mitogenome sequences revealed that Asian citrus psyllid (Diaphorina citri) from California was related to those from Florida but different from those in Southern China

    Science.gov (United States)

    Asian citrus psyllid (ACP, Diaphorina citri Kuwayama; Hemiptera: Liviidae) transmits “Candidatus Liberibacter asiaticus” (CLas), an unculturable alpha-proteobacterium associated with citrus Huanglongbing (HLB, yellow shoot disease, also called citrus greening disease). HLB is threatening citrus prod...

  9. Oviposition behaviour of the soil mite Pergamasus brevicornis (Acari: Parasitidae).

    Science.gov (United States)

    Marquardt, Tomasz; Faleńczyk-Koziróg, Katarzyna; Kaczmarek, Sławomir

    2013-07-01

    We observed the oviposition behaviour of the soil mite Pergamasus brevicornis Berlese (Acari: Parasitidae) using continuous video-monitoring. Oviposition consisted of six sequential phases. The first phase (I) involved inspection of the substrate. In the second phase (II) there were rhythmic movements of the first pair of legs and slight reciprocating movements of the body. The third (III) was a resting phase. In the fourth phase (IV) the gnathosoma was lowered and the body was raised. In the next phase (V) there were two sub-phases. During the first (Va), the female held the egg below the gnathosoma. In the second sub-phase (Vb), the gnathosoma moved up holding the egg, which was then placed on the substrate. The last phase (VI) involved intense 'cleaning' movements of the chelicerae and palps. During Va a protective external eggshell structure is gradually formed, involving a phase where the egg shell is sticky. After moving the egg to the substrate, the female freed her palps and chelicerae from the sticky egg shell and cleaned her gnathosomal appendages. Phases II-V took on average 207 ± 69 s.

  10. Catalogue of ptyctimous mites (Acari, Oribatida) of the world.

    Science.gov (United States)

    NiedbaŁa, Wojciech; Liu, Dong

    2018-03-11

    As important representatives of Oribatida (Acari), ptyctimous mites comprise more than 1400 described species in 40 genera and subgenera, with nearly cosmopolitan distribution except for the Arctic and Antarctic Regions. They are capable of folding the aspidosoma under the opisthosoma to protect their appendages, and are primarily soil and litter inhabitants, feeding on fungi and decaying plant remains with various levels of specificity. Our purpose was to provide a detailed catalogue of all known ptyctimous mite species in the world with information of distribution, taxonomic issues and some remarks. Data of known juvenile  instars of ptyctimous mites which were not included in Norton Ermilov (2014) were added. We hope that our catalogue with bibliography will be helpful in taxonomic and ecological studies.        The catalogue presents taxonomic information and geographic distribution of 1431 known species of the world belonging to 42 genera and eight families (not including data of genus and species inquirenda, nomina nuda and species without author name). Among them, 261 species are listed as synonyms, 43 species inquirenda, nine homonyms, 17 new synonyms, one new subgenus Mahuntritia subgenus nov. and three new names are included in the catalogue.

  11. Double-stranded RNA uptake through topical application, mediates silencing of five CYP4 genes and suppresses insecticide resistance in Diaphorina citri.

    Science.gov (United States)

    Killiny, Nabil; Hajeri, Subhas; Tiwari, Siddharth; Gowda, Siddarame; Stelinski, Lukasz L

    2014-01-01

    Silencing of genes through RNA interference (RNAi) in insects has gained momentum during the past few years. RNAi has been used to cause insect mortality, inhibit insect growth, increase insecticide susceptibility, and prevent the development of insecticide resistance. We investigated the efficacy of topically applied dsRNA to induce RNAi for five Cytochrome P450 genes family 4 (CYP4) in Diaphorina citri. We previously reported that these CYP4 genes are associated with the development of insecticide resistance in D. citri. We targeted five CYP4 genes that share a consensus sequence with one dsRNA construct. Quantitative PCR confirmed suppressed expression of the five CYP4 genes as a result of dsRNA topically applied to the thoracic region of D. citri when compared to the expression levels in a control group. Western blot analysis indicated a reduced signal of cytochrome P450 proteins (45 kDa) in adult D. citri treated with the dsRNA. In addition, oxidase activity and insecticide resistance were reduced for D. citri treated with dsRNA that targeted specific CYP4 genes. Mortality was significantly higher in adults treated with dsRNA than in adults treated with water. Our results indicate that topically applied dsRNA can penetrate the cuticle of D. citri and induce RNAi. These results broaden the scope of RNAi as a mechanism to manage pests by targeting a broad range of genes. The results also support the application of RNAi as a viable tool to overcome insecticide resistance development in D. citri populations. However, further research is needed to develop grower-friendly delivery systems for the application of dsRNA under field conditions. Considering the high specificity of dsRNA, this tool can also be used for management of D. citri by targeting physiologically critical genes involved in growth and development.

  12. Double-stranded RNA uptake through topical application, mediates silencing of five CYP4 genes and suppresses insecticide resistance in Diaphorina citri.

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    Nabil Killiny

    Full Text Available Silencing of genes through RNA interference (RNAi in insects has gained momentum during the past few years. RNAi has been used to cause insect mortality, inhibit insect growth, increase insecticide susceptibility, and prevent the development of insecticide resistance. We investigated the efficacy of topically applied dsRNA to induce RNAi for five Cytochrome P450 genes family 4 (CYP4 in Diaphorina citri. We previously reported that these CYP4 genes are associated with the development of insecticide resistance in D. citri. We targeted five CYP4 genes that share a consensus sequence with one dsRNA construct. Quantitative PCR confirmed suppressed expression of the five CYP4 genes as a result of dsRNA topically applied to the thoracic region of D. citri when compared to the expression levels in a control group. Western blot analysis indicated a reduced signal of cytochrome P450 proteins (45 kDa in adult D. citri treated with the dsRNA. In addition, oxidase activity and insecticide resistance were reduced for D. citri treated with dsRNA that targeted specific CYP4 genes. Mortality was significantly higher in adults treated with dsRNA than in adults treated with water. Our results indicate that topically applied dsRNA can penetrate the cuticle of D. citri and induce RNAi. These results broaden the scope of RNAi as a mechanism to manage pests by targeting a broad range of genes. The results also support the application of RNAi as a viable tool to overcome insecticide resistance development in D. citri populations. However, further research is needed to develop grower-friendly delivery systems for the application of dsRNA under field conditions. Considering the high specificity of dsRNA, this tool can also be used for management of D. citri by targeting physiologically critical genes involved in growth and development.

  13. Attractiveness of Host Plant Volatile Extracts to the Asian Citrus Psyllid, Diaphorina citri, is Reduced by Terpenoids from the Non-Host Cashew.

    Science.gov (United States)

    Fancelli, Marilene; Borges, Miguel; Laumann, Raul A; Pickett, John A; Birkett, Michael A; Blassioli-Moraes, Maria C

    2018-04-01

    Diaphorina citri is a vector of the bacterial causative agent of Huanglongbing (HLB = Citrus greening), a severe disease affecting citrus crops. As there is no known control for HLB, manipulating insect behaviour through deployment of semiochemicals offers a promising opportunity for protecting citrus crops. The behavioural responses of D. citri to plant volatiles, and the identity of these plant volatiles were investigated. Volatiles were collected from host plants Murraya paniculata, Citrus sinensis, C. reshni, C. limettioides, Poncirus trifoliata, and from non-host plants Psidium guajava, Mangifera indica, Anacardium occidentale. In behavioural assays, female D. citri spent more time in the arms containing volatiles from either M. paniculata or C. sinensis compared to the control arms. When D. citri was exposed to volatiles collected from A. occidentale, they preferred the control arm. Volatiles emitted from the other studied plants did not influence the foraging behaviour of D. citri. Chemical analyses of volatile extracts from C. sinensis, M. paniculata, and A. occidentale revealed the presence of the terpenoids (E)-4,8-dimethylnona-1,3,7-triene (DMNT) and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) in higher amounts in A. occidentale. In further behavioural bioassays, female D. citri spent less time in arms containing a synthetic blend of DMNT and TMTT compared to the control arms. Female D. citri also spent less time in arms containing the synthetic blend in combination with volatile extracts from either M. paniculata or C. sinensis compared to the control arms. Results suggest that higher release of the two terpenoids by A. occidentale make this species unattractive to D. citri, and that the terpenoids could be used in reducing colonisation of citrus plants and therefore HLB infection.

  14. Citrus tristeza virus-based RNAi in citrus plants induces gene silencing in Diaphorina citri, a phloem-sap sucking insect vector of citrus greening disease (Huanglongbing).

    Science.gov (United States)

    Hajeri, Subhas; Killiny, Nabil; El-Mohtar, Choaa; Dawson, William O; Gowda, Siddarame

    2014-04-20

    A transient expression vector based on Citrus tristeza virus (CTV) is unusually stable. Because of its stability it is being considered for use in the field to control Huanglongbing (HLB), which is caused by Candidatus Liberibacter asiaticus (CLas) and vectored by Asian citrus psyllid, Diaphorina citri. In the absence of effective control strategies for CLas, emphasis has been on control of D. citri. Coincident cohabitation in phloem tissue by CLas, D. citri and CTV was exploited to develop a novel method to mitigate HLB through RNA interference (RNAi). Since CTV has three RNA silencing suppressors, it was not known if CTV-based vector could induce RNAi in citrus. Yet, expression of sequences targeting citrus phytoene desaturase gene by CTV-RNAi resulted in photo-bleaching phenotype. CTV-RNAi vector, engineered with truncated abnormal wing disc (Awd) gene of D. citri, induced altered Awd expression when silencing triggers ingested by feeding D. citri nymphs. Decreased Awd in nymphs resulted in malformed-wing phenotype in adults and increased adult mortality. This impaired ability of D. citri to fly would potentially limit the successful vectoring of CLas bacteria between citrus trees in the grove. CTV-RNAi vector would be relevant for fast-track screening of candidate sequences for RNAi-mediated pest control. Copyright © 2014. Published by Elsevier B.V.

  15. Effects of methoprene, a juvenile hormone analog, on survival of various developmental stages, adult emergence, reproduction and behavior of Asian citrus psyllid, Diaphorina citri Kuwayama.

    Science.gov (United States)

    Brar, Gurpreet S; Meyer, Wendy; Stelinski, Lukasz L

    2015-12-01

    The Asian citrus citrus psyllid, Diaphorina citri Kuwayama, transmits a bacterium that causes huanglongbing in citrus. Frequent and repeated use of neurotoxic insecticides against D. citri has resulted in the development of insecticide resistance. We evaluated the effects of the juvenile hormone analog methoprene on egg hatch, nymphal development, adult emergence, reproduction and behavior of D. citri. Methoprene significantly reduced the viability of eggs that were between 0 and 4 days old. Egg hatch of 0-48-h-old and 49-96-h-old eggs was 8 and 9%, respectively, when treated with 320 µg mL(-1) of methoprene. Methoprene caused significant mortality of first-, third- and fifth-instar D. citri nymphs and reduced adult emergence as compared with controls. Methoprene caused less than 5% adult emergence when first- and third-instar stages were treated, respectively, and less than 40% adult emergence when fifth instars were treated. Reduced fertility of females was observed when they emerged from methoprene-treated fifth instars. Methoprene was effective in reducing egg hatch, suppressing nymphal development and decreasing adult emergence of D. citri under laboratory conditions. Treatment of fifth instars reduced the fertility of females. Methoprene might be a possible tool for integrated management of D. citri. © 2015 Society of Chemical Industry.

  16. Better Together: Association With ‘Candidatus Liberibacter Asiaticus’ Increases the Reproductive Fitness of Its Insect Vector, Diaphorina citri (Hemiptera: Liviidae)

    Science.gov (United States)

    Pelz-Stelinski, K. S.; Killiny, N.

    2016-01-01

    The duration of the evolutionary association between a pathogen and vector can be inferred based on the strength of their mutualistic interactions. A well-adapted pathogen is likely to confer some benefit or, at a minimum, exhibit low pathogenicity toward its host vector. Coevolution of the two toward a mutually beneficial association appears to have occurred between the citrus greening disease pathogen, Candidatus Liberibacter asiaticus (Las), and its insect vector, the Asian citrus psyllid, Diaphorina citri (Kuwayama). To better understand the dynamics facilitating transmission, we evaluated the effects of Las infection on the fitness of its vector. Diaphorina citri harboring Las were more fecund than their uninfected counterparts; however, their nymphal development rate and adult survival were comparatively reduced. The finite rate of population increase and net reproductive rate were both greater among Las-infected D. citri as compared with uninfected counterparts, indicating that overall population fitness of infected psyllids was improved given the greater number of offspring produced. Previous reports of transovarial transmission, in conjunction with increased fecundity and population growth rates of Las-positive D. citri found in the current investigation, suggest a long evolutionary relationship between pathogen and vector. The survival of Las-infected adult D. citri was lower compared with uninfected D. citri, which suggests that there may be a fitness trade-off in response to Las infection. A beneficial effect of a plant pathogen on vector fitness may indicate that the pathogen developed a relationship with the insect before secondarily moving to plants. PMID:27418697

  17. Metabolomic Response to Huanglongbing: Role of Carboxylic Compounds in Citrus sinensis Response to 'Candidatus Liberibacter asiaticus' and Its Vector, Diaphorina citri.

    Science.gov (United States)

    Killiny, Nabil; Nehela, Yasser

    2017-08-01

    Huanglongbing, a destructive disease of citrus, is caused by the fastidious bacterium 'Candidatus Liberibacter asiaticus' and transmitted by Asian citrus psyllid, Diaphorina citri. The impact of 'Ca. L. asiaticus' infection or D. citri infestation on Valencia sweet orange (Citrus sinensis) leaf metabolites was investigated using gas chromatography mass spectrometry, followed by gene expression analysis for 37 genes involved in jasmonic acid (JA), salicylic acid (SA), and proline-glutamine pathways. The total amino acid abundance increased after 'Ca. L. asiaticus' infection, while the total fatty acids increased dramatically after infestation with D. citri, compared with control plants. Seven amino acids (glycine, l-isoleucine, l-phenylalanine, l-proline, l-serine, l-threonine, and l-tryptophan) and five organic acids (benzoic acid, citric acid, fumaric acid, SA, and succinic acid) increased in 'Ca. L. asiaticus'-infected plants. On the other hand, the abundance of trans-JA and its precursor α-linolenic increased in D. citri-infested plants. Surprisingly, the double attack of both D. citri infestation and 'Ca. L. asiaticus' infection moderated the metabolic changes in all chemical classes studied. In addition, the gene expression analysis supported these results. Based on these findings, we suggest that, although amino acids such as phenylalanine are involved in citrus defense against 'Ca. L. asiaticus' infection through the activation of an SA-mediated pathway, fatty acids, especially α-linolenic acid, are involved in defense against D. citri infestation via the induction of a JA-mediated pathway.

  18. Thiamethoxam and imidacloprid drench applications on sweet orange nursery trees disrupt the feeding and settling behaviour of Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Miranda, Marcelo P; Yamamoto, Pedro T; Garcia, Rafael B; Lopes, João Pa; Lopes, João Rs

    2016-09-01

    Chemical control is the method most used for management of Diaphorina citri, the vector of the phloem-limited bacteria associated with citrus huanglongbing (HLB) disease. The objectives of this study were to determine the influence of soil-drench applications of neonicotinoids (thiamethoxam and imidacloprid) on the probing behaviour of D. citri on citrus nursery trees, using the electrical penetration graph (EPG) technique, and to measure the D. citri settling behaviour after probing on citrus nursery trees that had received these neonicotinoid treatments. The drench applications of neonicotinoids on citrus nursery trees disrupt D. citri probing, mainly for EPG variables related to phloem sap ingestion, with a significant reduction (≈90%) in the duration of this activity compared with untreated plants in all assessment periods (15, 35 and 90 days after application). Moreover, both insecticides have a repellent effect on D. citri, resulting in significant dispersal of psyllids from treated plants. This study clearly demonstrates the interference of soil-applied neonicotinoids on the feeding and settling behaviour of D. citri on citrus nursery trees, mainly during the phloem ingestion phase. These findings reinforce the recommendation of drench application of neonicotinoids before planting nursery trees as a useful strategy for HLB management. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  19. Spatial distribution of Diaphorina citri Kuwayama (Hemiptera: Psyllidae in citrus orchards Distribuição espacial de Diaphorina citri Kuwayama (Hemiptera: Psyllidae em pomares de citros

    Directory of Open Access Journals (Sweden)

    Marilia Gregolin Costa

    2010-10-01

    Full Text Available The psyllid Diaphorina citri Kuwayama is one of the most important pests of citrus, mainly because it is the vector of the bacterium that causes huanglongbing (HLB or 'Greening' disease. To study the spatial distribution of nymphs and adults of this pest, an experiment was carried out in two 'Valencia' sweet orange orchards, four and 12 years of age, established in Matão, central area of São Paulo state, Brazil. The following dispersion indices were used to study pest aggregation in the citrus plants: variance/mean relationship (I, index of Morisita (Iδ, coefficient of Green (Cx, the exponent of negative binomial distribution, common k (c and Taylor's Power Law for each sampling. The negative binomial distribution was more representative of the spatial distribution of this psyllid, for both nymphs and adults. For most samplings, psyllid nymphs found in branches and adults caught in traps had an aggregated distribution.O psilídeo Diaphorina citri Kuwayama tornou-se nos últimos anos uma das mais importantes pragas na cultura de citros, principalmente pelos prejuízos causados às plantas por ser o transmissor da bactéria causadora da doença Huanglongbing (HLB ou 'Greening'. Com a finalidade de estudar a distribuição espacial de ninfas e adultos desta praga, instalaram-se experimentos em duas áreas de citros com histórico de ocorrência de HLB, no município de Matão (região central do Estado de São Paulo, em plantas de laranja 'Valência', com quatro e 12 anos de idade. Para estudo da agregação da população nas plantas, foram utilizados os seguintes índices de dispersão: razão variância/média (I, índice de Morisita (Iδ, coeficiente de Green (Cx e expoente da distribuição binomial negativa, k comum (c e lei da potência de Taylor para cada amostragem. A distribuição binomial negativa foi o modelo mais adequado para representar a distribuição espacial do psilídeo, tanto para ninfas como para adultos. Na maioria das

  20. Natural Head Posture in the Setting of Sagittal Spinal Deformity: Validation of Chin-Brow Vertical Angle, Slope of Line of Sight, and McGregor's Slope With Health-Related Quality of Life.

    Science.gov (United States)

    Lafage, Renaud; Challier, Vincent; Liabaud, Barthelemy; Vira, Shaleen; Ferrero, Emmanuelle; Diebo, Bassel G; Liu, Shian; Vital, Jean-Marc; Mazda, Keyvan; Protopsaltis, Themistocles S; Errico, Thomas J; Schwab, Frank J; Lafage, Virginie

    2016-07-01

    The maintenance of horizontal gaze is an essential function of upright posture and global sagittal spinal alignment. Horizontal gaze is classically measured by the chin-brow vertical angle (CBVA), which is not readily measured on most lateral spine radiographs. To evaluate relations between CBVA and the slope of the line of sight, the slope of McGregor's line (McGS), and Oswestry Disability Index. Patients were identified from a single center database of 531 spine patients who underwent full-body EOS x-rays. Correlations between CBVA, the slope of the line of sight, and McGS were assessed. Using a quadratic regression with Oswestry Disability Index and CBVA, windows of low disability were identified. Comparison of sagittal spinopelvic parameters was carried out between patients with "ascending gaze" and "neutral position." Three hundred three patients were included (74% female, mean age 54.8 years, body mass index 26.6 ± 6.0 kg/m). CBVA strongly correlated with the slope of the line of sight (r = 0.996) and McGS (r = 0.862). Regression studies between Oswestry Disability Index and CBVA yielded a range of values corresponding to low disability (-4.7 degrees to 17.7 degrees). Similarly, a low disability range for the slope of the line of sight (-5.1 degrees to 18.5 degrees) and McGS (-5.7 degrees to 14.3 degrees) was computed. Patients with "ascending gaze" had a worse spinopelvic alignment than "neutral position" patients. The slope of the line of sight and McGS correlated strongly with CBVA and can be used as surrogate measures. The range of values for these measures corresponding to low disability was identified. These values can be used as a general guideline to assess alignment for diagnostic purposes. Cervical compensatory mechanism may modify the natural head position in sagittally misaligned patients. CBVA, chin-brow vertical angleHRQoL, health-related quality of lifeMcGS, slope of McGregor's lineODI, Oswestry Disability IndexSLs, slope of the line of sight.

  1. A large parasitengonid mite (Acari, Erythraeoidea from the Early Cretaceous Crato Formation of Brazil

    Directory of Open Access Journals (Sweden)

    J. A. Dunlop

    2007-08-01

    Full Text Available A new large, fossil mite (Arachnida: Acari, Pararainbowia martilli n. gen. n. sp., is described from the Early Cretaceous (Aptian Crato Formation from Ceará State, Brazil. It is assigned to the Cohort Parasitengona and the superfamily Erythraeoidea, some extant members of which can reach up to seven millimetres in body length. Given that doubts have been raised about the identity of putative Crato feather mite eggs, this new fossil represents the first unequivocal record of Acari from the Crato Formation, the first non-amber record of an erythraeoid mite and the oldest named example of this superfamily. Fossil erythraeoids from Mesozoic and Tertiary ambers are briefly reviewed – including a widely overlooked Late Cretaceous species – with comments on Mesozoic mites in general. Thirteen Baltic amber erythraeoids have been formally described, but much unstudied material from various amber sources remains. Ein neues großes Milbenfossil (Arachnida: Acari, Pararainbowia martilli n. gen. n. sp., wird aus der Crato Formation (Unterkreide, Aptium des Ceará Gebietes in Brasilien beschrieben. Es wird der Kohorte Parasitengona und der Überfamilie Erythraeoidea zugeordnet; die modernen Vertreter erreichen eine Körperlänge bis zu sieben mm. Weil die Identität von Federmilbeneiern aus der Crato Formation in Frage gestellt wurde, ist dieser Neufund der erste klare Hinweis von Acari aus der Crato Formation. Es ist die erste erythraeoide Milbe, die nicht aus dem Bernstein stammt sowie das älteste genannte Beispiel dieser Überfamilie. Fossile erythraeoide Milben aus dem Bernstein des Mesozoikum und des Tertiärs werden kurz zusammengefasst – u. a. eine weitgehend übersehene Art aus der Oberkreide – mit allgemeinen Anmerkungen zu den mesozoischen Milben. Dreizehn erythraeoide Milbenarten sind aus dem baltischen Bernstein genannt und beschrieben worden, aber weiteres unbearbeitetes Material von verschiedenen Bernstein-Fundpunkten liegt noch vor

  2. Acaricidal and repellent activities of essential oil of Eucalyptus globulus against Dermanyssus gallinae (Acari: Mesostigmata)

    OpenAIRE

    Dehghani-Samani Amir; Madreseh-Ghahfarokhi Samin; Dehghani-Samani Azam; Pirali-Kheirabadi Khodadad

    2015-01-01

    Introduction: By considering an increase in drug resistance against red mites, finding the nonchemical herbal acaricide against Dermanyssus gallinae (De Geer) (Acari: Mesostigmata) is necessary to kill them and to reduce the chemical resistance against chemical acaricides in this specie. Dermanyssus gallinae is a potential vector of the causal agent of several viral diseases such as Equine encephalitis and St. Louis encephalitis. It can be a vector of bacteria such as Salmonella spp., Mycobac...

  3. Chemical Composition, Antioxidant and Antimicrobial Activity of Pericarpium Citri Reticulatae Essential Oil

    Directory of Open Access Journals (Sweden)

    Bei Gao

    2011-05-01

    Full Text Available The chemical composition, antioxidant and antimicrobial activity of Pericarpium Citri Reticulatae (PCR essential oil obtained using an improved Clevenger type apparatus were studied. Among the five different PCRs examined the highest yield of essential oil was found in Chachi 2004 (harvested and stored in 2004 and the lowest in Chachi 2008 (harvested and stored in 2008. Fifty three different volatile compounds were determined, including terpenic hydrocarbons, alcohols, aldehydes, ketones and esters. D-limonene, one of terpenes, was the major constituent in PCR. The antioxidant capacity of PCR essential oil varied considerably with the duration of storage time, and the oil from Chachi 1994 has the strongest ferric-reducing antioxidant power. In addition, the essential oil possessed varying degrees of antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, except Streptococcus faecalis, while had no effect on Gram-negative bacteria (Escherichia coli, Enterobacter cloacae.

  4. Temporal progression of 'Candidatus Liberibacter asiaticus' infection in citrus and acquisition efficiency by Diaphorina citri.

    Science.gov (United States)

    Coletta-Filho, Helvecio D; Daugherty, Matthew P; Ferreira, Cléderson; Lopes, João R S

    2014-04-01

    Over the last decade, the plant disease huanglongbing (HLB) has emerged as a primary threat to citrus production worldwide. HLB is associated with infection by phloem-limited bacteria ('Candidatus Liberibacter' spp.) that are transmitted by the Asian citrus psyllid, Diaphorina citri. Transmission efficiency varies with vector-related aspects (e.g., developmental stage and feeding periods) but there is no information on the effects of host-pathogen interactions. Here, acquisition efficiency of 'Candidatus Liberibacter asiaticus' by D. citri was evaluated in relation to temporal progression of infection and pathogen titer in citrus. We graft inoculated sweet orange trees with 'Ca. L. asiaticus'; then, at different times after inoculation, we inspected plants for HLB symptoms, measured bacterial infection levels (i.e., titer or concentration) in plants, and measured acquisition by psyllid adults that were confined on the trees. Plant infection levels increased rapidly over time, saturating at uniformly high levels (≈10(8) copy number of 16S ribosomal DNA/g of plant tissue) near 200 days after inoculation-the same time at which all infected trees first showed disease symptoms. Pathogen acquisition by vectors was positively associated with plant infection level and time since inoculation, with acquisition occurring as early as the first measurement, at 60 days after inoculation. These results suggest that there is ample potential for psyllids to acquire the pathogen from trees during the asymptomatic phase of infection. If so, this could limit the effectiveness of tree rouging as a disease management tool and would likely explain the rapid spread observed for this disease in the field.

  5. GENETIC Diaphorina citri DIVERSITY ON CITRUS CROPS OF THE VALLE DEL CAUCA AND QUINDÍO (COLOMBIA

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    MIGUEL ANGEL MONCAYO-DONOSO

    2014-07-01

    Full Text Available The Asiatic psyllid Diaphorina citri (Hemiptera: Psyllidae is the main vector of Candidatus liberibacter, which causes the Huanglongbing HLB disease, known for devastating citrus in the world but not yet reported in Colombia. The genetic variability of the D. citri population was studied through sequencing the COI mitochondrial gene as molecular marker. Adults were collected in citrus producing zones of the Colombian Valle del Cauca and Quindío. Amplification was performed with two pairs of specific primers for Hemiptera. The PCR products were sequenced at Macrogen-Korea, obtaining a total of 124 sequences. For the bioinformatic analysis, the Vector NTI 11.5, Harlequin V 3.5, MEGA 5 and MAFFT 6 programs were used. The molecular diversity indices between populations were similar, revealing a common origin and a recent split of the populations excluding a significant genetic differentiation associated to variations of the bacterium, however the haplotype diversity index was higher than the nucleotide diversity index. The latter one showed a low number of polymorphic sites, indicating that the D. citri populations are expanding. The study of the vector’s genetic variability is a tool for the prediction of likely scenarios for the spread of diseases.

  6. Diaphorina citri Nymphs Are Resistant to Morphological Changes Induced by "Candidatus Liberibacter asiaticus" in Midgut Epithelial Cells.

    Science.gov (United States)

    Mann, Marina; Fattah-Hosseini, Somayeh; Ammar, El-Desouky; Stange, Richard; Warrick, EricaRose; Sturgeon, Kasie; Shatters, Robert; Heck, Michelle

    2018-04-01

    " Candidatus Liberibacter asiaticus" is the causative bacterium associated with citrus greening disease. " Ca Liberibacter asiaticus" is transmitted by Diaphorina citri more efficiently when it is acquired by nymphs rather than adults. Why this occurs is not known. We compared midguts of D. citri insects reared on healthy or " Ca Liberibacter asiaticus"-infected citrus trees using quantitative PCR, confocal microscopy, and mitochondrial superoxide staining for evidence of oxidative stress. Consistent with its classification as propagative, " Ca Liberibacter asiaticus" titers were higher in adults than in nymphs. Our previous work showed that adult D. citri insects have basal levels of karyorrhexis (fragmentation of the nucleus) in midgut epithelial cells, which is increased in severity and frequency in response to " Ca Liberibacter asiaticus." Here, we show that nymphs exhibit lower levels of early-stage karyorrhexis than adults and are refractory to the induction of advanced karyorrhexis by " Ca Liberibacter asiaticus" in the midgut epithelium. MitoSox Red staining showed that guts of infected adults, particularly males, experienced oxidative stress in response to " Ca Liberibacter asiaticus." A positive correlation between the titers of " Ca Liberibacter asiaticus" and the Wolbachia endosymbiont was observed in adult and nymph midguts, suggesting an interplay between these bacteria during development. We hypothesize that the resistance of the nymph midgut to late-stage karyorrhexis through as yet unknown molecular mechanisms benefits " Ca Liberibacter asiaticus" for efficient invasion of midgut epithelial cells, which may be a factor explaining the developmental dependency of " Ca Liberibacter asiaticus" acquisition by the vector.

  7. β-caryophyllene emitted from a transgenic Arabidopsis or chemical dispenser repels Diaphorina citri, vector of Candidatus Liberibacters.

    Science.gov (United States)

    Alquézar, Berta; Volpe, Haroldo Xavier Linhares; Magnani, Rodrigo Facchini; de Miranda, Marcelo Pedreira; Santos, Mateus Almeida; Wulff, Nelson Arno; Bento, Jose Mauricio Simões; Parra, José Roberto Postali; Bouwmeester, Harro; Peña, Leandro

    2017-07-17

    Production of citrus, the main fruit tree crop worldwide, is severely threatened by Huanglongbing (HLB), for which as yet a cure is not available. Spread of this bacterial disease in America and Asia is intimately connected with dispersal and feeding of the insect vector Diaphorina citri, oligophagous on rutaceous host plants. Effective control of this psyllid is an important component in successful HLB management programs. Volatiles released from the non-host guava have been shown to be repellent to the psyllid and to inhibit its response to citrus odour. By analysing VOC emission from guava we identified one volatile compound, (E)-β-caryophyllene, which at certain doses exerts a repellent effect on D. citri. Non-host plant rejection mediated by (E)-β-caryophyllene is demonstrated here by using Arabidopsis over-expression and knock-out lines. For the first time, results indicate that genetically engineered Arabidopsis plants with modified emission of VOCs can alter the behaviour of D. citri. This study shows that transgenic plants with an inherent ability to release (E)-β-caryophyllene can potentially be used in new protection strategies of citrus trees against HLB.

  8. Essential Oil Variation from Twenty Two Genotypes of Citrus in Brazil—Chemometric Approach and Repellency Against Diaphorina citri Kuwayama

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    Moacir dos Santos Andrade

    2016-06-01

    Full Text Available The chemical composition of volatile oils from 22 genotypes of Citrus and related genera was poorly differentiated, but chemometric techniques have clarified the relationships between the 22 genotypes, and allowed us to understand their resistance to D. citri. The most convincing similarities include the synthesis of (Z-β-ocimene and (E-caryophyllene for all 11 genotypes of group A. Genotypes of group B are not uniformly characterized by essential oil compounds. When stimulated with odor sources of 22 genotypes in a Y-tube olfactometer D. citri preferentially entered the arm containing the volatile oils of Murraya paniculata, confirming orange jasmine as its best host. C. reticulata × C. sinensis was the least preferred genotype, and is characterized by the presence of phytol, (Z-β-ocimene, and β-elemene, which were not found in the most preferred genotype. We speculate that these three compounds may act as a repellent, making these oils less attractive to D. citri.

  9. Marine water mites (Acari: Hydrachnidia: Pontarachnidae) from Taiwan, Korea and India, with the first description of the male of Pontarachna australis Smit, 2003

    Digital Repository Service at National Institute of Oceanography (India)

    Pesic, V.; Chatterjee, T.; Chan, B.K.K.; Ingole, B.S.

    he hitherto unknown male of the marine water mite Pontarachna australis Smit, 2003 (Acari: Hydrachnidia: Pontarachnidae) is described and recorded from Taiwan for the first time. Another marine water mite, Litarachna denhami (Lohmann, 1909...

  10. Sobre o condicionamento alimentar na cochonilha-branca, Planococcus citri (Risso (Hemiptera: pseudococcidae Regarding to host conditioning in citrus mealybug Planococcus citri (Risso (Hemiptera: pseudococcidae

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    Lenira Viana Costa Santa-Cecília

    2013-03-01

    Full Text Available Estudos do comportamento alimentar mediante a técnica de "Electrical Penetration Graphs" (EPG das cochonilhas-farinhentas (Pseudococcidae provenientes de um hospedeiro de criação alternativo têm mostrado que esses insetos não atingem ou demoram cerca de 9 horas para alcançar a fase floemática. Por outro lado, aqueles provenientes do hospedeiro-fonte atingem a fase floemática mais rapidamente e apresentam maior frequência de alimentação nos vasos crivados. Esses resultados indicam a presença do fenômeno de condicionamento alimentar, ainda não demonstrado em cochonilhas. Assim, o presente trabalho teve como objetivo determinar a existência desse fenômeno em Planococcus citri (Risso (Hemiptera: Pseudococcidae. Foram realizados testes de livre escolha, monitoramento eletrônico (EPG e estudos de alguns parâmetros biológicos. Em todos os experimentos, o cafeeiro (Coffea arabica L., os citros (Citrus sinensis L. e abóbora (Cucurbita maxima L. foram utilizados como substratos de criação (fonte da cochonilha, sendo os tratamentos constituídos pela combinação entre os hospedeiros-fonte e os hospedeiros receptores (café e citros. O teste de escolha entre cafeeiro e citros nas primeiras 72 horas mostrou que as cochonilhas criadas em cafeeiro apresentaram preferência pelo cafeeiro; aquelas originadas dos citros mostraram uma tendência, embora não significativa, em selecionar os citros em relação ao cafeeiro e aquelas criadas em abóbora não mostraram preferência por nenhum dos hospedeiros. Os estudos do comportamento alimentar mediante o monitoramento eletrônico (EPG mostraram que a fase floemática, considerada como a fase de aceitação do hospedeiro, foi mais frequente em cafeeiro, seja com cochonilhas oriundas deste substrato, seja de citros. Aqueles insetos mantidos em abóbora e transferidos para o cafeeiro ou citros apresentaram excepcionalmente ou não apresentaram nenhuma fase floemática, respectivamente. A

  11. Phylogeography of Diaphorina citri (Hemiptera: Liviidae) and its primary endosymbiont, 'Candidatus Carsonella ruddii': an evolutionary approach to host-endosymbiont interaction.

    Science.gov (United States)

    Wang, Yanjing; Lu, Jinming; Beattie, George Ac; Islam, Mohammad R; Om, Namgay; Dao, Hang T; Van Nguyen, Liem; Zaka, Syed M; Guo, Jun; Tian, Mingyi; Deng, Xiaoling; Tan, Shunyun; Holford, Paul; He, Yurong; Cen, Yijing

    2018-03-25

    In insects, little is known about the co-evolution between their primary endosymbionts and hosts at the intraspecific level. This study examined co-diversification between the notorious agricultural pest Diaphorina citri and its primary endosymbionts (P-endosymbiont), 'Candidatus Carsonella ruddii' at the population level. Maximum likelihood, haplotype network, principal components and Bayesian clustering identified three lineages for D. citri and its P-endosymbiont: a Western clade containing individuals from Pakistan, Bhutan (Phuentsholing), Vietnam (Son La), USA, Myanmar and China (Ruili, Yunnan); a Central clade, with accessions originating from Southwest China, Bhutan (Tsirang) and Bangladesh; and an Eastern clade containing individuals from Southeast Asia, and East and South China. A more diverse genetic structure was apparent in the host mitochondrial DNA than their P-endosymbionts; however, the two sets of data were strongly congruent. This study provides evidence for the co-diversification of D. citri and its P-endosymbiont during the migration from South Asia to East and Southeast Asia. We also suggest that the P-endosymbiont may facilitate investigations into the genealogy and migration history of the host. The biogeography of D. citri and its P-endosymbiont indicated that D. citri colonized and underwent a secondary dispersal from South Asia to East and Southeast Asia. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  12. Global genetic variation in the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae) and the endosymbiont Wolbachia: links between Iran and the USA detected.

    Science.gov (United States)

    Lashkari, Mohammadreza; Manzari, Shahab; Sahragard, Ahad; Malagnini, Valeria; Boykin, Laura M; Hosseini, Reza

    2014-07-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is one of the most serious pests of citrus in the world, because it transmits the pathogen that causes citrus greening disease. To determine genetic variation among geographic populations of D. citri, microsatellite markers, mitochondrial gene cytochrome oxidase I (mtCOI) and the Wolbachia-Diaphorina, wDi, gene wsp sequence data were used to characterize Iranian and Pakistani populations. Also, a Bayesian phylogenetic technique was utilized to elucidate the relationships among the sequences data in this study and all mtCOI and wsp sequence data available in GenBank and the Wolbachia database. Microsatellite markers revealed significant genetic differentiation among Iranian populations, as well as between Iranian and Pakistani populations (FST  = 0.0428, p citri populations in Iran, India, Saudi Arabia, Brazil, Mexico, Florida and Texas (USA) are similar. Wolbachia, wDi, wsp sequences were similar among Iranian populations, but different between Iranian and Pakistani populations. The South West Asia (SWA) group is the most likely source of the introduced Iranian populations of D. citri. This assertion is also supported by the sequence similarity of the Wolbachia, wDi, strains from the Florida, USA and Iranian D. citri. These results should be considered when looking for biological controls in either country. © 2013 Society of Chemical Industry.

  13. The predatory mite Neoseiulus womersleyi (Acari: Phytoseiidae) follows extracts of trails left by the two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae).

    Science.gov (United States)

    Shinmen, Tsubasa; Yano, Shuichi; Osakabe, Mh

    2010-10-01

    As it walks, the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) spins a trail of silk threads, that is followed by the predatory mite, Neoseiulus womersleyi Schicha (Acari: Phytoseiidae). Starved adult female N. womersleyi followed T. urticae trails laid down by five T. urticae females but did not follow a trail of one T. urticae female, suggesting that the amount of spun threads and their chemical components should correlate positively with the number of T. urticae individuals. To examine whether chemical components of T. urticae trails are responsible for the predatory mite's trail following, we collected separate T. urticae threads from the exuviae and eggs, and then washed the threads with methanol to separate chemical components from physical attributes of the threads. Female N. womersleyi did not follow T. urticae trails that had been washed with methanol but contained physical residues, but they did follow the direction to which the methanol extracts of the T. urticae trails was applied. These results suggest that the predatory mite follows chemical, not physical, attributes of T. urticae trails.

  14. Ticks (Acari: Ixodida) on wild carnivores in Brazil.

    Science.gov (United States)

    Labruna, Marcelo B; Jorge, Rodrigo S P; Sana, Dênis A; Jácomo, Anah Tereza A; Kashivakura, Cyntia K; Furtado, Mariana M; Ferro, Claudia; Perez, Samuel A; Silveira, Leandro; Santos, Tarcísio S; Marques, Samuel R; Morato, Ronaldo G; Nava, Alessandra; Adania, Cristina H; Teixeira, Rodrigo H F; Gomes, Albério A B; Conforti, Valéria A; Azevedo, Fernando C C; Prada, Cristiana S; Silva, Jean C R; Batista, Adriana F; Marvulo, Maria Fernanda V; Morato, Rose L G; Alho, Cleber J R; Pinter, Adriano; Ferreira, Patrícia M; Ferreira, Fernado; Barros-Battesti, Darci M

    2005-01-01

    The present study reports field data of ticks infesting wild carnivores captured from July 1998 to September 2004 in Brazil. Additional data were obtained from one tick collection and from previous published data of ticks on carnivores in Brazil. During field work, a total of 3437 ticks were collected from 89 Cerdocyon thous (crab-eating fox), 58 Chrysocyon brachyurus (maned wolf), 30 Puma concolor (puma), 26 Panthera onca (jaguar), 12 Procyon cancrivorus (crab-eating raccoon), 4 Speothos venaticus (bush dog), 6 Pseudalopex vetulus (hoary fox), 6 Nasua nasua (coati), 6 Leopardus pardalis (ocelot), 2 Leopardus tigrinus (oncilla), 1 Leopardus wiedii (margay), 1 Herpailurus yagouaroundi (jaguarundi), 1 Oncifelis colocolo (pampas cat), 1 Eira barbara (tayara), 1 Galictis vittata (grison), 1 Lontra longicaudis (neotropical otter), and 1 Potus flavus (kinkajou). Data obtained from the Acari Collection IBSP included a total of 381 tick specimens collected on 13 C. thous, 8 C. brachyurus, 3 P. concolor, 10 P. onca, 3 P. cancrivorus, 4 N. nasua, 1 L. pardalis, 1 L. wiedii, 4 H. yagouaroundi, 1 Galictis cuja (lesser grison), and 1 L. longicaudis. The only tick-infested carnivore species previously reported in Brazil, for which we do not present any field data are Pseudalopex gymnocercus (pampas fox), Conepatus chinga (Molina's hog-nosed skunk), and Conepatus semistriatus (striped hog-nosed skunk). We report the first tick records in Brazil on two Felidae species (O. colocolo, H. yagouaroundi), two Canidae species (P. vetulus, S. venaticus), one Procyonidae species (P. flavus) and one Mustelidae (E. barbara). Tick infestation remains unreported for 5 of the 26 Carnivora species native in Brazil: Oncifelis geoffroyi (Geoffroy's cat), Atelocynus microtis (short-eared dog), Pteronura brasiliensis (giant otter), Mustela africana (Amazon weasel), and Bassaricyon gabbii (olingo). Our field data comprise 16 tick species represented by the genera Amblyomma (12 species), Ixodes (1

  15. New feather mites of the subfamily Pterodectinae (Acari: Astigmata: Proctophyllodidae) from passerines (Aves: Passeriformes) in Mato Grosso do Sul, Brazil

    Czech Academy of Sciences Publication Activity Database

    Mironov, S. V.; Literák, I.; Čapek, Miroslav

    2008-01-01

    Roč. 1947, - (2008), s. 1-38 ISSN 1175-5326 Institutional research plan: CEZ:AV0Z60930519 Keywords : Acari * Astigmata * feather mites * systematics * Brazil * Proctophyllodidae * Aves * Passeriformes Subject RIV: EG - Zoology Impact factor: 0.740, year: 2008 http://www.mapress.com/zootaxa/2008/f/zt01947p038.pdf

  16. Response of forest soil Acari to prescribed fire following stand structure manipulation in the southern Cascade Range.Can

    Science.gov (United States)

    Michael A. Camann; Nancy E. Gillette; Karen L. Lamoncha; Sylvia R. Mori

    2008-01-01

    We studied responses of Acari, especially oribatid mites, to prescribed low-intensity fire in an east side pine site in the southern Cascade Range in California. We compared oribatid population and assemblage responses to prescribed fire in stands that had been selectively logged to enhance old growth characteristics, in logged stands to minimize old growth...

  17. Effect of coconut palm proximities and Musa spp. germplasm resistance to colonization by Raoiella indica (Acari: Tenuipalpidae)

    Science.gov (United States)

    Although coconut (Cocos nucifera L.) is the predominant host for Raoiella indica Hirst (Acari: Tenuipalpidae), false spider mite infestations do occur on bananas and plantains (Musa spp. Colla). Since its introduction, the banana and plantain industries have been negatively impacted to different deg...

  18. Antennal and Abdominal Transcriptomes Reveal Chemosensory Genes in the Asian Citrus Psyllid, Diaphorina citri.

    Science.gov (United States)

    Wu, Zhongzhen; Zhang, He; Bin, Shuying; Chen, Lei; Han, Qunxin; Lin, Jintian

    2016-01-01

    The Asian citrus psyllid, Diaphorina citri is the principal vector of the highly destructive citrus disease called Huanglongbing (HLB) or citrus greening, which is a major threat to citrus cultivation worldwide. More effective pest control strategies against this pest entail the identification of potential chemosensory proteins that could be used in the development of attractants or repellents. However, the molecular basis of olfaction in the Asian citrus psyllid is not completely understood. Therefore, we performed this study to analyze the antennal and abdominal transcriptome of the Asian citrus psyllid. We identified a large number of transcripts belonging to nine chemoreception-related gene families and compared their expression in male and female adult antennae and terminal abdomen. In total, 9 odorant binding proteins (OBPs), 12 chemosensory proteins (CSPs), 46 odorant receptors (ORs), 20 gustatory receptors (GRs), 35 ionotropic receptors (IRs), 4 sensory neuron membrane proteins (SNMPs) and 4 different gene families encoding odorant-degrading enzymes (ODEs): 80 cytochrome P450s (CYPs), 12 esterase (ESTs), and 5 aldehyde dehydrogenases (ADE) were annotated in the D. citri antennal and abdominal transcriptomes. Our results revealed that a large proportion of chemosensory genes exhibited no distinct differences in their expression patterns in the antennae and terminal abdominal tissues. Notably, RNA sequencing (RNA-seq) data and quantitative real time-PCR (qPCR) analyses showed that 4 DictOBPs, 4 DictCSPs, 4 DictIRs, 1 DictSNMP, and 2 DictCYPs were upregulated in the antennae relative to that in terminal abdominal tissues. Furthermore, 2 DictOBPs (DictOBP8 and DictOBP9), 2 DictCSPs (DictOBP8 and DictOBP12), 4 DictIRs (DictIR3, DictIR6, DictIR10, and DictIR35), and 1 DictCYP (DictCYP57) were expressed at higher levels in the male antennae than in the female antennae. Our study provides the first insights into the molecular basis of chemoreception in this insect

  19. Antennal and Abdominal Transcriptomes Reveal Chemosensory Genes in the Asian Citrus Psyllid, Diaphorina citri.

    Directory of Open Access Journals (Sweden)

    Zhongzhen Wu

    Full Text Available The Asian citrus psyllid, Diaphorina citri is the principal vector of the highly destructive citrus disease called Huanglongbing (HLB or citrus greening, which is a major threat to citrus cultivation worldwide. More effective pest control strategies against this pest entail the identification of potential chemosensory proteins that could be used in the development of attractants or repellents. However, the molecular basis of olfaction in the Asian citrus psyllid is not completely understood. Therefore, we performed this study to analyze the antennal and abdominal transcriptome of the Asian citrus psyllid. We identified a large number of transcripts belonging to nine chemoreception-related gene families and compared their expression in male and female adult antennae and terminal abdomen. In total, 9 odorant binding proteins (OBPs, 12 chemosensory proteins (CSPs, 46 odorant receptors (ORs, 20 gustatory receptors (GRs, 35 ionotropic receptors (IRs, 4 sensory neuron membrane proteins (SNMPs and 4 different gene families encoding odorant-degrading enzymes (ODEs: 80 cytochrome P450s (CYPs, 12 esterase (ESTs, and 5 aldehyde dehydrogenases (ADE were annotated in the D. citri antennal and abdominal transcriptomes. Our results revealed that a large proportion of chemosensory genes exhibited no distinct differences in their expression patterns in the antennae and terminal abdominal tissues. Notably, RNA sequencing (RNA-seq data and quantitative real time-PCR (qPCR analyses showed that 4 DictOBPs, 4 DictCSPs, 4 DictIRs, 1 DictSNMP, and 2 DictCYPs were upregulated in the antennae relative to that in terminal abdominal tissues. Furthermore, 2 DictOBPs (DictOBP8 and DictOBP9, 2 DictCSPs (DictOBP8 and DictOBP12, 4 DictIRs (DictIR3, DictIR6, DictIR10, and DictIR35, and 1 DictCYP (DictCYP57 were expressed at higher levels in the male antennae than in the female antennae. Our study provides the first insights into the molecular basis of chemoreception in this

  20. Double-stranded RNA delivery through soaking mediates silencing of the muscle protein 20 and increases mortality to the Asian citrus psyllid, Diaphorina citri.

    Science.gov (United States)

    Yu, Xiudao; Gowda, Siddarame; Killiny, Nabil

    2017-09-01

    Asian citrus psyllid, Diaphorina citri Kuwayama, is the most important economic pest of citrus because it transmits Candidatus Liberibacter asiaticus (CLas), the causal agent of huanglongbing (HLB). Silencing genes by RNA interference (RNAi) is a promising approach for controlling D. citri. RNAi-based insect management strategies depend on the selection of suitable target genes. The muscle protein 20 gene DcMP20 was characterized from D. citri in an effort to impair proper muscle development through RNAi. Phylogenetic analysis showed that DcMP20 was more closely related to MP20 from Drosophila compared with its counterpart from other insect species. Developmental expression analysis revealed that transcription of DcMP20 was development dependent and reached a maximum level in the last instar (fourth-fifth) of the nymphal stage. The extent of RNAi in D. citri was dose dependent, with dsRNA-DcMP20 at 75 ng µL -1 being sufficient to knock down endogenous DcMP20 expression, which resulted in significant mortality and reduced body weight that positively correlated with the silencing of DcMP20. No effect was found when dsRNA-GFP or water was used, indicating the specific effect of dsRNA-DcMP20. Our results suggest that dsRNA can be delivered to D. citri through soaking, and DcMP20 is an effective RNAi target to be used in the management of D. citri. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  1. Susceptibilities of Candidatus Liberibacter asiaticus-infected and noninfected Diaphorina citri to entomopathogenic fungi and their detoxification enzyme activities under different temperatures.

    Science.gov (United States)

    Hussain, Mubasher; Akutse, Komivi Senyo; Lin, Yongwen; Chen, Shiman; Huang, Wei; Zhang, Jinguan; Idrees, Atif; Qiu, Dongliang; Wang, Liande

    2018-03-25

    Some entomopathogenic fungi species, Isaria fumosorosea, and Hirsutella citriformis were found to be efficient against the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). However, the susceptibility to these fungi increases when the psyllid infected with Candidatus Liberibacter asiaticus (Las), which is transmitted by D. citri and causes citrus greening disease. In this study, we examined the Las-infected and Las-uninfected D. citri susceptibility to entomopathogenic fungi at different temperature regimes (5-40°C). When D. citri adults exposed to cold temperature (5°C), they showed less susceptibility to entomopathogenic fungi as compared with control (27°C). Irrespective of infection with Las, a significantly positive correlation was observed between temperature and percentage mortality caused by different isolates of I. fumosorosea, 3A Ifr, 5F Ifr, PS Ifr, and H. citriformis isolates, HC3D and 2H. In contrast, a significantly negative correlation was found between temperature and percentage mortality for 3A Ifr for both Las-infected and Las-uninfected psyllids. Detoxification enzymes, Glutathione S-transferase levels in D. citri showed a negative correlation, whereas cytochrome P450 and general esterase levels were not correlated with changes in temperature. These findings revealed that detoxification enzymes and general esterase levels are not correlated with altered susceptibility to entomopathogenic fungi at the different temperature regimes. Conclusively, temperature fluctuations tested appear to be a significant factor impacting the management strategies of D. citri using entomopathogenic fungi. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  2. Patogenicidade de Beauveria bassiana ao psilídeo Diaphorina citri e compatibilidade do fungo com produtos fitossanitários Beauveria bassiana pathogenicity to Diaphorina citri and compatibility of the fungus with phytosanitary products

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    Ana Paula Ferreira Pinto

    2012-12-01

    Full Text Available O objetivo deste trabalho foi avaliar a patogenicidade de Beauveria bassiana a ninfas de Diaphorina citri (Hemiptera: Psyllidae e verificar a compatibilidade do fungo com produtos fitossanitários e sua persistência em plantas de citros. Ninfas de D. citri foram pulverizadas com B. bassiana, nas concentrações 5x10(6, 1x10(7, 5x10(7, 1x10(8, 5x10(8 e 1x10(9 conídios mL-1, para determinação da concentração letal. Para avaliação da compatibilidade do fungo com produtos fitossanitários, extrato de nim e cinco inseticidas de quatro grupos químicos diferentes foram incorporados individualmente ao meio de cultura BDA em que o fungo foi cultivado. Avaliaram-se o crescimento vegetativo, a esporulação e a viabilidade do entomopatógeno. Plantas de citros, mantidas em casa de vegetação, foram tratadas primeiramente com os produtos fitossanitários e depois com o entomopatógeno. Avaliaram-se os tempos de exposição de 24 horas e de 7 e 14 dias. O fungo foi patogênico às ninfas de D. citri; a CL50 foi de 0,4x10(7 e a CL90 de 6,7x10(7 conidios mL-1, no décimo dia de avaliação. Em laboratório, os produtos fitosssanitários reduzem o crescimento do fungo. Em casa de vegetação, os produtos não afetam a sobrevivência do fungo nas plantas de citros.The objective of this work was to evaluate the pathogenicity of Beauveria bassiana to Diaphorina citri (Hemiptera: Psyllidae nymphs, and to check the compatibility of the fungus with phytosanitary products, and its persistence in citrus plants. Nymphs of D. citri were sprayed with B. bassiana in the concentrations 5x10(6, 1x10(7, 5x10(7, 1x10(8, 5x10(8 and 1x10(9 conidia mL-1 for lethal concentration determination. In order to evaluate the compatibility of the phytosanitary products with the fungus, neem extract and five insecticides of four different chemical groups were individually added to PDA culture medium, in which the fungus was cultivated. Vegetative growth, sporulation and viability

  3. Two-Spotted Ladybeetle Adalia bipunctata L. (Coleoptera: Coccinellidae): A Commercially Available Predator to Control Asian Citrus Psyllid Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Khan, Azhar A; Qureshi, Jawwad A; Afzal, Muhammad; Stansly, Philip A

    2016-01-01

    The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is an economically important pest of citrus because it serves as a vector of the causal pathogens of huanglongbing (HLB) also known as citrus greening disease. The increased use of insecticides for control of D. citri negatively impacts several natural enemies including some effective ladybeetle species which are not available commercially. The two-spotted ladybeetle, Adalia bipunctata (Coleoptera: Coccinellidae) is found in some crop and forest ecosystems of Asia, Europe and North America and available commercially. It is known to attack aphids and mealybugs but there are no published records of feeding on psyllids. We evaluated suitability and preference of A. bipunctata for nymphs of D. citri compared to corn leaf aphid Rhopalosiphum maidis (Hemiptera: Aphididae) a global pest of cereal crops and prey for many predaceous insects. We also compared development and reproduction of A. bipunctata on these two species with frozen eggs of the Mediterranean flour moth Ephestia kuehniella (Lepidoptera: Pyralidae) at 25°C. Initially, more D. citri than R. maidis nymphs were consumed in the no-choice tests although final consumption by larva and adult of A. bipunctata did not differ in the choice and no-choice tests. Larval development was prolonged by one day on D. citri compared to R. maidis nymphs but did not differ between either of these diets and E. kuehniella. Larval survival to adult averaged 93-100% and was not impacted by diet. Adult life span did not differ between diets although those on D. citri and R. maidis nymphs weighed less and produced fewer but more fertile eggs than on E. kuehniella eggs. Significant reduction of D. citri nymphs averaging 54% was observed in colonies caged with adult A. bipunctata on field planted citrus. R° (net reproductive rate) was least for beetles fed R. maidis, but otherwise there were no significant differences in demographic parameters. Successful

  4. The GC/MS Analysis of Volatile Components Extracted by Different Methods from Exocarpium Citri Grandis

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    Zhisheng Xie

    2013-01-01

    Full Text Available Volatile components from Exocarpium Citri Grandis (ECG were, respectively, extracted by three methods, that is, steam distillation (SD, headspace solid-phase microextraction (HS-SPME, and solvent extraction (SE. A total of 81 compounds were identified by gas chromatography-mass spectrometry including 77 (SD, 56 (HS-SPME, and 48 (SE compounds, respectively. Despite of the extraction method, terpenes (39.98~57.81% were the main volatile components of ECG, mainly germacrene-D, limonene, 2,6,8,10,14-hexadecapentaene, 2,6,11,15-tetramethyl-, (E,E,E-, and trans-caryophyllene. Comparison was made among the three methods in terms of extraction profile and property. SD relatively gave an entire profile of volatile in ECG by long-time extraction; SE enabled the analysis of low volatility and high molecular weight compounds but lost some volatiles components; HS-SPME generated satisfactory extraction efficiency and gave similar results to those of SD at analytical level when consuming less sample amount, shorter extraction time, and simpler procedure. Although SD and SE were treated as traditionally preparative extractive techniques for volatiles in both small batches and large scale, HS-SPME coupled with GC/MS could be useful and appropriative for the rapid extraction and qualitative analysis of volatile components from medicinal plants at analytical level.

  5. Resistance of Citrus and Related Genera to Diaphorina citri Kuwayama (Hemiptera: Liviidae).

    Science.gov (United States)

    Borgoni, P C; Vendramim, J D; Lourencão, A L; Machado, M A

    2014-10-01

    The present study was developed to evaluate the resistance of the following genotypes of Citrus and related genera to this pest: 'Pera,' 'Natal', and 'Washington Navel' oranges (Citrus sinensis), 'Marsh Seedless' grapefruit (Citrus paradisi), hardy orange 'Rubidoux' (Poncirus trifoliata), kumquat (Fortunella margarita Swingle), citrumelo 'Swingle' (C. paradisi x P. trifoliata), and citrange 'Troyer' (P. trifoliata x C. sinensis). The experiments were performed in greenhouses with plants grafted onto 'Rangpur' lime (Citrus limonia) and placed individually in voile cages. The preference for oviposition in a no-choice test, and the effect of genotype were evaluated. The egg-adult cycle was monitored to determine the effect of genotype on the biology of the insect. Poncirus 'Rubidoux' was the least preferred genotype for oviposition; reduced number of eggs was also found to occur on citrange 'Troyer', and 'Marsh Seedless' was the genotype with the most eggs. No significant variation in the duration of the embryonic period was observed; however, a difference in the viability of eggs was found, with the lowest egg viabilities on 'Swingle.' Kumquat and 'Marsh Seedless' genotypes were correlated with increased durations of the nymphal phase, however, there was no difference in the survival of this phase. Fecundity of females on 'Troyer', 'Swingle', and kumquat was reduced. Considering all of the evaluated parameters, it was concluded that cultivars of sweet orange are the most susceptible genotypes to Diaphorina citri. Regarding oviposition, P. trifoliata 'Rubidoux' showed resistance of the antixenosis type.

  6. Disease Development and Symptom Expression of Xanthomonas axonopodis pv. citri in Various Citrus Plant Tissues.

    Science.gov (United States)

    Vernière, C J; Gottwald, T R; Pruvost, O

    2003-07-01

    ABSTRACT Experimental inoculations of Xanthomonas axonopodis pv. citri in different tissues of Tahiti lime and Pineapple sweet orange were conducted monthly under natural conditions on Réunion Island. The interactions between a set of environmental and epidemic variables associated with disease expression and 184 different factor combinations were investigated to determine the parameters needed to explain Asiatic citrus canker (ACC) disease expression. Area under the disease progress curve (AUDPC), inoculation date (Id), fruit and leaf age ratings (FAR and LAR), and number of days during the first 2 weeks postinoculation for which the temperature was less than 14 degrees C (T(min)) or more than 28 degrees C (T(max)) were retained by principal component analysis and canonical correlation analysis as the most meaningful epidemic and environmental variables, respectively. AUDPC as the strongest dependent variable and combinations of the environmental variables as independent variables were used in multiple regression analyses. Tissue age rating at the time of infection was a good predictor for disease resulting from spray inoculation on fruits and leaves and also on fruits following a wound inoculation. Temperature, as expressed by T(min) or T(max), was also a significant factor in determining disease development described by AUDPC. Mature green stems were highly susceptible after wounding, similarly to leaves, but buds and leaf scars expressed the lowest susceptibility. These variations in disease expression according to the tissues will have different impacts on ACC epidemiology.

  7. Population diversity of Diaphorina citri (Hemiptera: Liviidae) in China based on whole mitochondrial genome sequences.

    Science.gov (United States)

    Wu, Fengnian; Jiang, Hongyan; Beattie, G Andrew C; Holford, Paul; Chen, Jianchi; Wallis, Christopher M; Zheng, Zheng; Deng, Xiaoling; Cen, Yijing

    2018-04-24

    Diaphorina citri (Asian citrus psyllid; ACP) transmits 'Candidatus Liberibacter asiaticus' associated with citrus Huanglongbing (HLB). ACP has been reported in 11 provinces/regions in China, yet its population diversity remains unclear. In this study, we evaluated ACP population diversity in China using representative whole mitochondrial genome (mitogenome) sequences. Additional mitogenome sequences outside China were also acquired and evaluated. The sizes of the 27 ACP mitogenome sequences ranged from 14 986 to 15 030 bp. Along with three previously published mitogenome sequences, the 30 sequences formed three major mitochondrial groups (MGs): MG1, present in southwestern China and occurring at elevations above 1000 m; MG2, present in southeastern China and Southeast Asia (Cambodia, Indonesia, Malaysia, and Vietnam) and occurring at elevations below 180 m; and MG3, present in the USA and Pakistan. Single nucleotide polymorphisms in five genes (cox2, atp8, nad3, nad1 and rrnL) contributed mostly in the ACP diversity. Among these genes, rrnL had the most variation. Mitogenome sequences analyses revealed two major phylogenetic groups of ACP present in China as well as a possible unique group present currently in Pakistan and the USA. The information could have significant implications for current ACP control and HLB management. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  8. Exposure to Guava Affects Citrus Olfactory Cues and Attractiveness to Diaphorina citri (Hemiptera: Psyllidae).

    Science.gov (United States)

    Barman, Jagadish Chandra; Campbell, Stuart A; Zeng, Xinnian

    2016-06-01

    Intercropping can reduce agricultural pest incidence, and represents an important sustainable alternative to conventional pest control methods. Understanding the ecological mechanisms for intercropping could help optimize its use, particularly in tropical systems which present a large number of intercropping possibilities. Citrus is threatened worldwide by greening disease (huanglongbing, HLB) vectored by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). Control of HLB and citrus psyllid can be partially achieved through intercropping with guava, Psidium guajava L., but the mechanisms remain unclear. We tested the hypothesis that guava olfactory cues affect psyllid behavior by altering the attractiveness of citrus through plant-plant interactions. In choice and no-choice cage experiments, psyllid settlement was reduced on citrus shoots that had been exposed to guava shoot odors for at least 2 h. In Y-tube olfactometer experiments, psyllids oriented to odors of unexposed, compared with guava-exposed, citrus shoots. These behavioral results indicate that a mechanism for the success of guava intercropping for sustainable, ecological disease management may be the indirect effect of guava on citrus attractiveness. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Odorants for surveillance and control of the Asian Citrus Psyllid (Diaphorina citri.

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    Iliano V Coutinho-Abreu

    Full Text Available The Asian Citrus Psyllid (ACP, Diaphorina citri, can transmit the bacterium Candidatus Liberibacter while feeding on citrus flush shoots. This bacterium causes Huanglongbing (HLB, a major disease of citrus cultivation worldwide necessitating the development of new tools for ACP surveillance and control. The olfactory system of ACP is sensitive to variety of odorants released by citrus plants and offers an opportunity to develop new attractants and repellents.In this study, we performed single-unit electrophysiology to identify odorants that are strong activators, inhibitors, and prolonged activators of ACP odorant receptor neurons (ORNs. We identified a suite of odorants that activated the ORNs with high specificity and sensitivity, which may be useful in eliciting behavior such as attraction. In separate experiments, we also identified odorants that evoked prolonged ORN responses and antagonistic odorants able to suppress neuronal responses to activators, both of which can be useful in lowering attraction to hosts. In field trials, we tested the electrophysiologically identified activating odorants and identified a 3-odor blend that enhances trap catches by ∼230%.These findings provide a set of odorants that can be used to develop affordable and safe odor-based surveillance and masking strategies for this dangerous pest insect.

  10. Species clarification of Isaria isolates used as biocontrol agents against Diaphorina citri (Hemiptera: Liviidae) in Mexico.

    Science.gov (United States)

    Gallou, Adrien; Serna-Domínguez, María G; Berlanga-Padilla, Angélica M; Ayala-Zermeño, Miguel A; Mellín-Rosas, Marco A; Montesinos-Matías, Roberto; Arredondo-Bernal, Hugo C

    2016-03-01

    Entomopathogenic fungi belonging to the genus Isaria (Hypocreales: Cordycipitaceae) are promising candidates for microbial control of insect pests. Currently, the Mexican government is developing a biological control program based on extensive application of Isaria isolates against Diaphorina citri (Hemiptera: Liviidae), a vector of citrus huanglongbing disease. Previous research identified three promising Isaria isolates (CHE-CNRCB 303, 305, and 307; tentatively identified as Isaria fumosorosea) from Mexico. The goal of this work was to obtain a complete morphological and molecular characterization of these isolates. Comparative analysis of morphology established that the isolates showed similar characteristics to Isaria javanica. Multi-gene analysis confirmed the morphological identification by including the three isolates within the I. javanica clade. Additionally, this work demonstrated the misidentifications of three other Isaria isolates (CHE-CNRCB 310 and 324: I. javanica, formerly I. fumosorosea; CHE-CNRCB 393: I. fumosorosea, formerly Isaria farinosa), underlying the need for a full and correct characterization of an isolate before developing a biological control program. Finally, the inter-simple sequence repeat (ISSR) genotyping method revealed that the CHE-CNRCB 303, 305, and 307 isolates belong to three different genotypes. This result indicates that ISSR markers could be used as a tool to monitor their presence in field conditions. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  11. The Genus Ixodes (Acari: Ixodidae) in Mexico: Adult Identification Keys, Diagnoses, Hosts, and Distribution

    Science.gov (United States)

    2010-01-01

    Cricetidae and Hominidae ( Homo sapiens Linnaeus, 1758) (Mammalia) (Hoffmann, 1969). Note. The tick from Valle de Bravo, Estado de México, was...distribution El género Ixodes (Acari: Ixodidae) en México: claves de identifi cación para adultos, diagnosis, huéspedes y distribución Carmen Guzmán...Incorporación de Profesores de Carrera en Facultades y Escuelas para el Fortalecimiento de la Investigación (PROFIP). Tila María Pérez, Curator of CNAC

  12. Mites (Acari Associated with the Desert Seed Harvester Ant, Messor pergandei (Mayr

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    Kaitlin A. Uppstrom

    2011-01-01

    Full Text Available Mites (Acari associated with the seed harvester ant Messor pergandei were investigated in the Sonoran desert of Arizona. At least seven representatives of the mite genera Armacarus, Lemanniella, Petalomium, Forcellinia, Histiostoma, Unguidispus, and Cosmoglyphus are phoretically associated with M. pergandei. Most of these morphospecies show preference for specific phoretic attachment sites and primarily use female alates rather than male alates for dispersal. Five mite morphospecies were found in low numbers inhabiting the chaff piles: Tydeidae sp., Procaeculus sp., Anystidae sp., Bakerdania sp., and Tetranychidae sp. The phoretic Petalomium sp. was observed consuming fungus growing on a dead queen, but the roles of the other mite species remain mostly unresolved.

  13. The impact of cucumber nitrogen nutrition on life history traits of Tetranychus urticae (Koch) (Acari: Tetranychidae)

    OpenAIRE

    Motahari , M.; Kheradmand , K.; Roustaee , A.M.; Talebi , A.A.

    2014-01-01

    International audience; The nutritional quality of the host plant is one of the most important factors of growth and reproduction for crop pests. In order to investigate the impact of nitrogen on the biology and demography of Tetranychus urticae Koch (Acari: Tetranychidae), cucumber plants were nourished by four levels of nitrogen: N1 (10 meq /L NO3-), N2 (12 meq/L NO3-), N3 (15 meq/L NO3-) and N4 (20 meq /L NO3-). The experiments were performed under laboratory conditions at 25+/-1 °C, 60+/-...

  14. Multiplexed lateral flow microarray assay for detection of citrus pathogens Xylella fastidiosa and Xanthomonas axonopodis pv citri

    Energy Technology Data Exchange (ETDEWEB)

    Cary,; Bruce, R [Santa Fe, NM; Stubben, Christopher J [Los Alamos, NM

    2011-03-22

    The invention provides highly sensitive and specific assays for the major citrus pathogens Xylella fastidiosa and Xanthomonas axonopodis, including a field deployable multiplexed assay capable of rapidly assaying for both pathogens simultaneously. The assays are directed at particular gene targets derived from pathogenic strains that specifically cause the major citrus diseases of citrus variegated chlorosis (Xylella fastidiosa 9a5c) and citrus canker (Xanthomonas axonopodis pv citri). The citrus pathogen assays of the invention offer femtomole sensitivity, excellent linear dynamic range, and rapid and specific detection.

  15. Occurrence of coccinellids that prey on Diaphorinia citri (Hemiptera:Liviidae) on Euphorbia heterophylla (Euphorbiacea) and Chamaecrista fasciculata (Fabaceae) in a south Florida residential area

    Science.gov (United States)

    Adding plant-based nutritional resources to a landscape may help to recruit and retain predaceous and parasitic arthropods. As a first step in determining whether the addition of nectary plants can increase the abundance and diversity of biocontrol agents of Diaphorina citri and psyllid suppression ...

  16. Use of the entomopathogenic fungi Metarhizium anisopliae, Cordyceps bassiana and Isaria fumosorosea to control Diaphorina citri (Hemiptera: Psylidae) in Persian lime under field conditions

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a destructive insect pest in the citriculture, because it is an efficient vector of the proteobacteria, ‘Candidatus Liberibacter asiaticus’ (Las), ‘Ca. L. Africanus’ (Laf), and ‘Ca. L. Americanus’ (Lam). These bacteria c...

  17. Cloning and expressing a highly functional and substrate specific farnesoic acid o-methyltransferase from the Asian citrus psyllid (Diaphorina citri Kuwayama)

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri, transmits a phloem-limited bacterium, Candidatus Liberibacter asiaticus that causes citrus greening disease. Because juvenile hormone (JH) plays an important role in adult and nymphal development, we studied the final steps in juvenile hormone biosynthesis...

  18. Natural parasitism of Diaphorina citri Kuwayama (Hemiptera, Psyllidae nymphs by Tamarixia radiata Waterston (Hymenoptera, Eulophidae in São Paulo orange groves

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    Paulo Eduardo Branco Paiva

    2012-12-01

    Full Text Available The psyllid Diaphorina citri Kuwayama 1908 has become the main citrus pest species in the state of São Paulo, Brazil, after the introduction of the huanglongbing or citrus greening. This study evaluated the parasitism of 3rd, 4th and 5th instar D. citri nymphs by Tamarixia radiata (Waterston, 1922 in citrus groves under a regimen of regular insecticide applications in ten producing regions: Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins and São João da Boa Vista. Sixty-nine samples of new branches infested with nymphs of D. citri were collected from 2005 to 2008 in orange groves ranging from 1 to 20 years old, of the varieties Hamlin, Pera, Valencia and Natal. The parasitoid T. radiata is widely distributed in São Paulo orange groves, and was identified in 50 (72% of the samples, showing a mean parasitism rate of 12.4%. The highest parasitism rate was observed in the "summer" (from January through March, with a mean of 25.7%. Nymphal parasitism was above 90% in two samples. The probable causes of the variations in parasitism of D. citri by T. radiata are discussed.

  19. Characterization of a recombinant Cathepsin B-Like cysteine peptidase from Diaphorina citri Kuwayama (Hemiptera: Liviidae): A putative target control of citrus huanglongbing

    Science.gov (United States)

    Huanglongbing (HLB) is one of the most destructive disease affecting citrus plants. The causal agent is associated with the phloem-limited bacterium Candidatus Liberibacter asiaticus (CLas) spread by the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae). Among the control strategies for H...

  20. Host range testing of Tamarixia radiata (Hymenoptera: Eulophidae) sourced from the Punjab of Pakistan for classical biological control of Diaphorina citri (Hemiptera: Liviidae: Euphyllurinae: Diaphorinini) in California.

    Science.gov (United States)

    Hoddle, Mark S; Pandey, Raju

    2014-02-01

    ABSTRACT Tests evaluating the host range of Tamarixia radiata (Waterson) (Hymenoptera: Eulophidae), a parasitoid of the pestiferous Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), sourced from the Punjab of Pakistan, were conducted in quarantine at the University of California, Riverside, CA. Seven nontarget psyllid species (five native and two self-introduced species) representing five families were exposed to T radiata under the following three different exposure scenarios: 1) sequential no-choice tests, 2) static no-choice tests, and 3) choice tests. Nontarget species were selected for testing based on the following criteria: 1) taxonomic relatedness to the target, D. citri; 2) native psyllids inhabiting native host plants related to citrus that could release volatiles attractive to T. radiata; 3) native psyllids with a high probability of occurrence in native vegetation surrounding commercial citrus groves that could be encountered by T. radiata emigrating from D. citri-infested citrus orchards; 4) a common native pest psyllid species; and 5) a beneficial psyllid attacking a noxious weed. The results of host range testing were unambiguous; T radiata exhibited a narrow host range and high host specificity, with just one species of nontarget psyllid, the abundant native pest Bactericera cockerelli Sulc, being parasitized at low levels (citri poses negligible environmental risk.

  1. Host Range Testing of Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae) for Use in Classical Biological Control of Diaphorina citri (Hemiptera: Liviidae) in California.

    Science.gov (United States)

    Bistline-East, Allison; Pandey, Raju; Kececi, Mehmet; Hoddle, Mark S

    2015-06-01

    Host range tests for Diaphorencyrtus aligarhensis (Shafee, Alam, & Agarwal) (Hymenoptera: Encyrtidae), an endoparasitoid of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), sourced from Punjab Pakistan, were conducted in quarantine at the University of California, Riverside, CA. Seven nontarget psyllid species representing four psyllid families were exposed to mated D. aligarhensis females in four different treatment types: 1) short sequential no-choice treatments, 2) prolonged sequential no-choice treatments, 3) prolonged no-choice static treatments, and 4) choice treatments. Selection of nontarget psyllid species was based on phylogenetic proximity to D. citri, likelihood of being encountered by D. aligarhensis in the prospective release areas in California, and psyllid species in biological control of invasive weeds. D. aligarhensis exhibited high host affinity to D. citri, and only parasitized one nontarget species, the pestiferous potato psyllid, Bactericera cockerelli (Sulc), at low levels (citri. Results presented here suggest D. aligarhensis poses minimal risk to nontarget psyllid species in California. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. A “walker” tool to place Diaphorina citri (Hemiptera: Liviidae) adults at predetermined sites for bioassays of behavior in citrus (Sapindales: Rutacease) trees

    Science.gov (United States)

    A walker tool was developed to assist placement of D. citri on citrus host trees in behavioral bioassays. The walker performs better than a commonly used paintbrush tool in the proportion of successful placements and in the reduction of jumps away from the citrus leaf, although it takes about two mi...

  3. Behavioral plasticity in feeding by Diaphorina citri (Hemiptera, Liviidae): ingestion from phloem versus xylem is influenced by leaf age and surface

    Science.gov (United States)

    Diaphorina citri is a major pest of citrus because it transmits the bacterium that causes Huanglongbing (HLB) (a.k.a. citrus greening). One approach to disease management is vector management using insecticides. However, knowledge of vector mortality alone is not sufficient if the vector has had tim...

  4. Reproductive parameters of Phytoseiulus macropilis (Banks fed with Tetranychus urticae Koch (Acari: Phytoseiidae, Tetranychidae in laboratory

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    G. C. Souza-Pimentel

    Full Text Available Abstract Predatory mites that belong to the Phytoseiidae family are one of the main natural enemies of phytophagous mites, thus allowing for their use as a biological control. Phytoseiulus macropilis (Banks, 1904 (Acari: Phytoseiidae is among the main species of predatory mites used for this purpose. Tetranychus urticae Koch, 1836 (Acari: Tetranychidae is considered to be one of the most important species of mite pests and has been described as attacking over 1,100 species of plants in 140 families with economic value. The objective of the present study was to investigate, in the laboratory, the reproductive parameters of the predatory mite P. macropilis when fed T. urticae. Experiments were conducted under laboratory conditions at 25 ± 2 °C of temperature, 70 ± 10% RH and 14 hours of photophase. In addition, biological aspects were evaluated and a fertility life table was established. The results of these experiments demonstrated that the longevity of adult female was 27.5 days and adult male was 29.0 days. The population was estimated to increase approximately 27 times (Ro in mean generation time (T, which was 17.7 days. Lastly, the mite population grew 1.2 times/day (λ and doubled every 3.7 days (TD.

  5. Plant architecture and prey distribution influence foraging behavior of the predatory mite Phytoseiulus persimilis (Acari: Phytoseiidae).

    Science.gov (United States)

    Gontijo, Lessando M; Nechols, James R; Margolies, David C; Cloyd, Raymond A

    2012-01-01

    The arrangement, number, and size of plant parts may influence predator foraging behavior, either directly, by altering the rate or pattern of predator movement, or, indirectly, by affecting the distribution and abundance of prey. We report on the effects of both plant architecture and prey distribution on foraging by the predatory mite, Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae), on cucumber (Cucumis sativus L.). Plants differed in leaf number (2- or 6-leafed), and there were associated differences in leaf size, plant height, and relative proportions of plant parts; but all had the same total surface area. The prey, the twospotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae), were distributed either on the basal leaf or on all leaves. The effect of plant architecture on predator foraging behavior varied depending on prey distribution. The dimensions of individual plant parts affected time allocated to moving and feeding, but they did not appear to influence the frequency with which predators moved among different plant parts. Overall, P. persimilis moved less, and fed upon prey longer, on 6-leafed plants with prey on all leaves than on plants representing other treatment combinations. Our findings suggest that both plant architecture and pattern of prey distribution should be considered, along with other factors such as herbivore-induced plant volatiles, in augmentative biological control programs.

  6. Development, oviposition, and mortality of Neoseiulus fallacis (Acari: Phytoseiidae) in response to reduced-risk insecticides.

    Science.gov (United States)

    Villanueva, Raul T; Walgenbach, James F

    2005-12-01

    Eight reduced-risk insecticides (acetamiprid, thiamethoxam, imidacloprid, thiacloprid, methoxyfenozide, pyriproxyfen, indoxacarb, and spinosad) and three conventional insecticides (azinphosmethyl, fenpropathrin, and esfenvalerate) were tested against Neoseiulus fallacis (Garman) (Acari: Phytoseiidae), the most abundant predacious mite in North Carolina apple (Malus spp.) orchards. To assess the effect of insecticides on development and mortality of N. fallacis immatures, 12-h-old eggs were individually placed on bean leaf disks previously dipped in insecticide solutions. Tetranychus urticae Koch (Acari: Tetranychidae) females were added as a food source. None of the reduced-risk insecticides significantly affected immature N. fallacis compared with the control; however, the pyrethroids esfenvalerate and fenpropathrin were highly toxic to immatures. To evaluate the effect of insecticides on mortality and oviposition of adult N. fallacis, 7- to 8-d-old females were confined on insecticide-treated bean leaves with Malephora crocea (Aizoaceae) pollen added as a food source. Spinosad resulted in the highest mortality, whereas azinphosmethyl, acetamiprid, fenpropathrin, and imidacloprid were moderately toxic, and mortality from esfenvalerate, indoxacarb, thiacloprid, methoxyfenozide, pyriproxyfen, and thiamethoxam did not differ significantly from the control. Oviposition was affected in a similar manner, with the exception of acetamiprid that did not affect oviposition, and thiamethoxam that reduced oviposition.

  7. Phytoseiid mites of the Canary Islands (Acari, Phytoseiidae. II. Tenerife and La Gomera Islands

    Directory of Open Access Journals (Sweden)

    Ferragut, F.

    2007-12-01

    Full Text Available Phytoseiid mites (Acari, Phytoseiidae inhabiting plants in natural ecosystems from Tenerife and La Gomera islands (Canary Islands have been studied. Surveys were conducted from 1997 to 2002. Eleven species were collected, one of them being reported for the first time from the Canary Islands and six of them reported for the first time from Tenerife and La Gomera islands. Euseius machadoi n. sp. collected from woody plants in the Canarian laurisilva is proposed as a new species.

    En muestreos realizados desde 1997 hasta 2002 se ha estudiado la fauna de ácaros fitoseidos (Acari, Phytoseiidae asociada a plantas de ecosistemas naturales de las islas de Tenerife y La Gomera (Islas Canarias. Se han recolectado un total de 11 especies, siendo una de ellas citada por vez primera en las islas Canarias y seis de ellas citadas por primera vez en las islas de Tenerife y La Gomera. Euseius machadoi n. sp., recolectado en plantas leñosas de la laurisilva canaria, se propone como una nueva especie.

  8. Sobre o condicionamento alimentar na cochonilha-branca, Planococcus citri (Risso (Hemiptera: pseudococcidae

    Directory of Open Access Journals (Sweden)

    Lenira Viana Costa Santa-Cecília

    2013-03-01

    Full Text Available Estudos do comportamento alimentar mediante a técnica de "Electrical Penetration Graphs" (EPG das cochonilhas-farinhentas (Pseudococcidae provenientes de um hospedeiro de criação alternativo têm mostrado que esses insetos não atingem ou demoram cerca de 9 horas para alcançar a fase floemática. Por outro lado, aqueles provenientes do hospedeiro-fonte atingem a fase floemática mais rapidamente e apresentam maior frequência de alimentação nos vasos crivados. Esses resultados indicam a presença do fenômeno de condicionamento alimentar, ainda não demonstrado em cochonilhas. Assim, o presente trabalho teve como objetivo determinar a existência desse fenômeno em Planococcus citri (Risso (Hemiptera: Pseudococcidae. Foram realizados testes de livre escolha, monitoramento eletrônico (EPG e estudos de alguns parâmetros biológicos. Em todos os experimentos, o cafeeiro (Coffea arabica L., os citros (Citrus sinensis L. e abóbora (Cucurbita maxima L. foram utilizados como substratos de criação (fonte da cochonilha, sendo os tratamentos constituídos pela combinação entre os hospedeiros-fonte e os hospedeiros receptores (café e citros. O teste de escolha entre cafeeiro e citros nas primeiras 72 horas mostrou que as cochonilhas criadas em cafeeiro apresentaram preferência pelo cafeeiro; aquelas originadas dos citros mostraram uma tendência, embora não significativa, em selecionar os citros em relação ao cafeeiro e aquelas criadas em abóbora não mostraram preferência por nenhum dos hospedeiros. Os estudos do comportamento alimentar mediante o monitoramento eletrônico (EPG mostraram que a fase floemática, considerada como a fase de aceitação do hospedeiro, foi mais frequente em cafeeiro, seja com cochonilhas oriundas deste substrato, seja de citros. Aqueles insetos mantidos em abóbora e transferidos para o cafeeiro ou citros apresentaram excepcionalmente ou não apresentaram nenhuma fase floemática, respectivamente. A

  9. Amplification of DNA of Xanthomonas axonopodis pv. citri from historic citrus canker herbarium specimens.

    Science.gov (United States)

    Li, Wenbin; Brlansky, Ronald H; Hartung, John S

    2006-05-01

    Herbaria are important resources for the study of the origins and dispersal of plant pathogens, particularly bacterial plant pathogens that incite local lesions in which large numbers of pathogen genomes are concentrated. Xanthomonas axonopodis pv. citri (Xac), the causal agent of citrus bacterial canker disease, is a notable example of such a pathogen. The appearance of novel strains of the pathogen in Florida and elsewhere make it increasingly important to understand the relationships among strains of this pathogen. USDA-ARS at Beltsville, Maryland maintains approximately 700 herbarium specimens with citrus canker disease lesions up to 90 years old, originally collected from all over the world, and so is an important resource for phytogeographic studies of this bacterium. Unfortunately, DNA in herbarium specimens is degraded and may contain high levels of inhibitors of PCR. In this study, we compared a total of 23 DNA isolation techniques in combination with 31 novel primer pairs in order to develop an efficient protocol for the analysis of Xac DNA in herbarium specimens. We identified the most reliable extraction method, identified in terms of successful amplification by our panel of 31 primer pairs. We also identified the most robust primer pairs, identified as successful in the largest number of extracts prepared by different methods. We amplified Xac genomic sequences up to 542 bp long from herbarium samples up to 89 years old. Primers varied in effectiveness, with some primer pairs amplifying Xac DNA from a 1/10,000 dilution of extract from a single lesion from a citrus canker herbarium specimen. Our methodology will be useful to identify pathogens and perform molecular analyses of bacterial and possibly fungal genomes from herbarium specimens.

  10. Effects of Candidatus Liberibacter asiaticus on the fitness of the vector Diaphorina citri.

    Science.gov (United States)

    Ren, S-L; Li, Y-H; Zhou, Y-T; Xu, W-M; Cuthbertson, A G S; Guo, Y-J; Qiu, B-L

    2016-12-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama transmits the bacterium 'Candidatus Liberibacter asiaticus' (Las), which causes citrus huanglongbing (HLB) disease. Although many studies have been conducted on the biology of ACP on different host plants, few have taken the plant, Las bacteria and the vector insect within one context to evaluate the effects of Las on the fitness of ACP under field conditions. Understanding the relationship between Las and ACP is critical for both ACP and HLB disease management. We estimated the development and survival of ACP immatures, the longevity and fecundity of ACP female adults in four treatments (Las-positive or -negative ACP on Las-infected and -free citrus plants). Las-positive ACP immatures developed significantly faster on Las-infected citrus than those on Las-free plants. The fecundity and longevity of Las-positive female adults were also greater, or longer on Las-infected citrus shoots, whereas the survival of Las-positive immatures was significantly lower on Las-infected citrus shoots, compared to those that developed on Las-free plants. Similarly, the intrinsic rate of population increase (r m ) was highest (0·1404) when Las-positive ACP fed on Las-infected citrus shoots and the lowest (0·1328) when the Las-negative ACP fed on Las-free citrus shoots. Both the Las infection in ACP and citrus plants had obvious effects on the biology of ACP. When compared to the Las infection in ACP insects, the Las infection in citrus shoots had a more significant effect on the fitness of ACP. To efficiently prevent the occurrence and spread of HLB disease, it is critical to understand the ecological basis of vector outbreaks and disease incidence, especially under field conditions. Thus, this study has increased our understanding of the epidemiology of HLB transmitted by psyllids in nature. © 2016 The Society for Applied Microbiology.

  11. Crystallization, data collection and phasing of the molybdate-binding protein of the phytopathogen Xanthomonas axonopodis pv. citri

    International Nuclear Information System (INIS)

    Santacruz, C. P.; Balan, A.; Ferreira, L. C. S.; Barbosa, J. A. R. G.

    2006-01-01

    The molybdate-binding protein (ModA) from X. axonopodis pv. citri was crystallized with sodium molybdate in the presence of PEG or sulfate. The crystal diffracted to a maximum resolution of 1.7 Å and belongs to the orthorhombic space group C222 1, with unit-cell parameters a = 68.15, b = 172.14, c = 112.04 Å. Xanthomonas axonopodis pv. citri ModA protein is the ABC periplasmic binding component responsible for the capture of molybdate. The protein was crystallized with sodium molybdate using the hanging-drop vapour-diffusion method in the presence of PEG or sulfate. X-ray diffraction data were collected to a maximum resolution of 1.7 Å using synchrotron radiation. The crystal belongs to the orthorhombic space group C222 1 , with unit-cell parameters a = 68.15, b = 172.14, c = 112.04 Å. The crystal structure was solved by molecular-replacement methods and structure refinement is in progress

  12. Crystal structure of diaphorin methanol monosolvate isolated from Diaphorina citri Kuwayama, the insect vector of citrus greening disease.

    Science.gov (United States)

    Szebenyi, D Marian; Kriksunov, Irina; Howe, Kevin J; Ramsey, John S; Hall, David G; Heck, Michelle L; Krasnoff, Stuart B

    2018-04-01

    The title compound C 22 H 39 NO 9 ·CH 3 OH [systematic name: ( S )- N -(( S )-{(2 S ,4 R ,6 R )-6-[( S )-2,3-di-hydroxy-prop-yl]-4-hy-droxy-5,5-di-methyl-tetra-hydro-2 H -pyran-2-yl}(hy-droxy)meth-yl)-2-hy-droxy-2-[(2 R ,5 R ,6 R )-2-meth-oxy-5,6-dimeth-yl-4-methyl-ene-tetra-hydro-2 H -pyran-2-yl]acetamide methanol monosolvate], was isolated from the Asian citrus psyllid, Diaphorina citri Kuwayama, and crystallizes in the space group P 2 1 . ' Candidatus Profftella armatura' a bacterial endosymbiont of D. citri , biosynthesizes diaphorin, which is a hybrid polyketide-nonribosomal peptide comprising two highly substituted tetra-hydro-pyran rings joined by an N -acyl aminal bridge [Nakabachi et al. (2013 ▸). Curr. Biol. 23 , 1478-1484]. The crystal structure of the title compound establishes the complete relative configuration of diaphorin, which agrees at all nine chiral centers with the structure of the methanol monosolvate of the di- p -bromo-benzoate derivative of pederin, a biogenically related compound whose crystal structure was reported previously [Furusaki et al. (1968 ▸). Tetra-hedron Lett. 9 , 6301-6304]. Thus, the absolute configuration of diaphorin is proposed by analogy to that of pederin.

  13. Crystal structure of diaphorin methanol monosolvate isolated from Diaphorina citri Kuwayama, the insect vector of citrus greening disease

    Directory of Open Access Journals (Sweden)

    D. Marian Szebenyi

    2018-04-01

    Full Text Available The title compound C22H39NO9·CH3OH [systematic name: (S-N-((S-{(2S,4R,6R-6-[(S-2,3-dihydroxypropyl]-4-hydroxy-5,5-dimethyltetrahydro-2H-pyran-2-yl}(hydroxymethyl-2-hydroxy-2-[(2R,5R,6R-2-methoxy-5,6-dimethyl-4-methylenetetrahydro-2H-pyran-2-yl]acetamide methanol monosolvate], was isolated from the Asian citrus psyllid, Diaphorina citri Kuwayama, and crystallizes in the space group P21. `Candidatus Profftella armatura' a bacterial endosymbiont of D. citri, biosynthesizes diaphorin, which is a hybrid polyketide–nonribosomal peptide comprising two highly substituted tetrahydropyran rings joined by an N-acyl aminal bridge [Nakabachi et al. (2013. Curr. Biol. 23, 1478–1484]. The crystal structure of the title compound establishes the complete relative configuration of diaphorin, which agrees at all nine chiral centers with the structure of the methanol monosolvate of the di-p-bromobenzoate derivative of pederin, a biogenically related compound whose crystal structure was reported previously [Furusaki et al. (1968. Tetrahedron Lett. 9, 6301–6304]. Thus, the absolute configuration of diaphorin is proposed by analogy to that of pederin.

  14. Dinâmica populacional e parasitismo natural de Diaphorina citri Kuwayama (Hemiptera: Liviidae em pomares de citros em Sergipe

    Directory of Open Access Journals (Sweden)

    Adriano Farias

    2018-04-01

    Abstract. The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Liviidae, which is the vector of the Hunglongbing (HLB bacterium, has become a key citrus pest in Brazil. In addition to citrus, the ornamental plant known as Orange Jasmine, Murraya paniculata (L. Jack, also hosts the psyllid. The present work aimed at studying the population dynamics of the psyllid in citrus orchards and its parasitism in citrus and M. paniculata in the state of Sergipe, the fourth largest citrus-producing state in Brazil. The evaluations were performed fortnightly for eleven months in seven Pera Citrus sinensis (L. Osbeck orange orchards located in two municipalities of Sergipe state (Boquim, and Umbauba. The populations of eggs, nymphs and adults of D. citri were compared among all orchards and all developmental stages were related to the abiotic factors temperature, relative humidity and precipitation, in each locality. The psyllid was classified as an accessory species (not very abundant in the orchards of Sergipe, showing a higher population density in November, December and March. Precipitation was the only abiotic factor that contributed to the population increase of adults of the psyllid. High rates of parasitism (55% of psyllid nymphs by the exotic parasitoid Tamarixia radiata Waterston (Hymenoptera: Eulophidae were detected in M. paniculata plants. Based on the results, if the HLB bacterium is detected in Sergipe, shorter samplings should be performed in the spring and summer months aiming at vector management. In addition, T. radiata could be released inundatively in integrated vector management programs.

  15. Crystallographic structure and substrate-binding interactions of the molybdate-binding protein of the phytopathogen Xanthomonas axonopodis pv. citri.

    Science.gov (United States)

    Balan, Andrea; Santacruz-Pérez, Carolina; Moutran, Alexandre; Ferreira, Luís Carlos Souza; Neshich, Goran; Gonçalves Barbosa, João Alexandre Ribeiro

    2008-02-01

    In Xanthomonas axonopodis pv. citri (Xac or X. citri), the modA gene codes for a periplasmic protein (ModA) that is capable of binding molybdate and tungstate as part of the ABC-type transporter required for the uptake of micronutrients. In this study, we report the crystallographic structure of the Xac ModA protein with bound molybdate. The Xac ModA structure is similar to orthologs with known three-dimensional structures and consists of two nearly symmetrical domains separated by a hinge region where the oxyanion-binding site lies. Phylogenetic analysis of different ModA orthologs based on sequence alignments revealed three groups of molybdate-binding proteins: bacterial phytopathogens, enterobacteria and soil bacteria. Even though the ModA orthologs are segregated into different groups, the ligand-binding hydrogen bonds are mostly conserved, except for Archaeglobus fulgidus ModA. A detailed discussion of hydrophobic interactions in the active site is presented and two new residues, Ala38 and Ser151, are shown to be part of the ligand-binding pocket.

  16. Crystallization, data collection and phasing of the molybdate-binding protein of the phytopathogen Xanthomonas axonopodis pv. citri

    Energy Technology Data Exchange (ETDEWEB)

    Santacruz, C. P.; Balan, A.; Ferreira, L. C. S. [Departamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, São Paulo, SP (Brazil); Barbosa, J. A. R. G., E-mail: joao@lnls.br [Centro de Biologia Molecular e Estrutural (CeBiMe), Laboratório Nacional de Luz Síncrotron (LNLS), CP 6192, Campinas, SP 13084-971 (Brazil); Departamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, São Paulo, SP (Brazil)

    2006-03-01

    The molybdate-binding protein (ModA) from X. axonopodis pv. citri was crystallized with sodium molybdate in the presence of PEG or sulfate. The crystal diffracted to a maximum resolution of 1.7 Å and belongs to the orthorhombic space group C222{sub 1,} with unit-cell parameters a = 68.15, b = 172.14, c = 112.04 Å. Xanthomonas axonopodis pv. citri ModA protein is the ABC periplasmic binding component responsible for the capture of molybdate. The protein was crystallized with sodium molybdate using the hanging-drop vapour-diffusion method in the presence of PEG or sulfate. X-ray diffraction data were collected to a maximum resolution of 1.7 Å using synchrotron radiation. The crystal belongs to the orthorhombic space group C222{sub 1}, with unit-cell parameters a = 68.15, b = 172.14, c = 112.04 Å. The crystal structure was solved by molecular-replacement methods and structure refinement is in progress.

  17. Low and Mid-Latitude Ionospheric Irregularities Studies Using TEC and Radio Scintillation Data from the CITRIS Radio Beacon Receiver in Low-Earth-Orbit

    Science.gov (United States)

    Siefring, C. L.; Bernhardt, P. A.; Huba, J.; Krall, J.; Roddy, P. A.

    2009-12-01

    Unique data on ionospheric plasma irregularities from the Naval Research Laboratory (NRL) CITRIS (Scintillation and TEC Receiver in Space) instrument will be presented. CITRIS is a multi-band receiver that recorded TEC (Total Electron Content) and radio scintillations from Low-Earth Orbit (LEO) on STPSat1. The 555+/5 km altitude 35° inclination orbit covers low and mid-latitudes. The measurements require propagation from a transmitter to a receiver through the F-region plasma. CITRIS used both 1) satellite beacons in LEO, such as the NRL CERTO (Coherent Electromagnetic Radio TOmography) beacons and 2) the global network of ground-based DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) beacons. The TEC measurements allow for tracking of ionospheric disturbances and irregularities while the measurements of scintillations can simultaneously characterize their effects. CITRIS was operated in a complementary fashion with the C/NOFS (Communication/Navigations Outages Forecasting System) satellite during most of its first year of operations. C/NOFS carries a three-frequency 150/400/1067 MHz CERTO beacon and is dedicated to the study of Spread-F. In the case of Spread-F, ionospheric irregularities start with large scale size density gradients (100s of km) and cascade through complex processes to short scale sizes (10s of meters). It is typically the 100m-1km scale features that harm communication and navigation systems through scintillations. A multi-sensor approach is needed to completely understand this complex system, such as, the combination of CITRIS remote radio sensing and C/NOFS in-situ data. Several types of irregularities have been studied including Spread-F and the newly discovered dawn-side depletions. Comparisons with the physics based SAMI3 model are being performed to help our understanding of the morphology of the irregularities.

  18. Risk assessment of various insecticides used for management of Asian citrus psyllid, Diaphorina citri in Florida citrus, against honey bee, Apis mellifera.

    Science.gov (United States)

    Chen, Xue Dong; Gill, Torrence A; Pelz-Stelinski, Kirsten S; Stelinski, Lukasz L

    2017-04-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a major pest of citrus trees worldwide. A wide variety of insecticides are used to manage D. citri populations within citrus groves in Florida. However, in areas shared by citrus growers and beekeepers the use of insecticides may increase the risks of Apis mellifera  L. (Hymenoptera: Apidae) loss and contaminated honey. The objective of this research was to determine the environmental toxicity of insecticides, spanning five different modes of action used to control D. citri, to A. mellifera. The insecticides investigated were imidacloprid, fenpropathrin, dimethoate, spinetoram and diflubenzuron. In laboratory experiments, LD 50 values were determined and ranged from 0.10 to 0.53 ng/μl for imidacloprid, fenpropathrin, dimethoate and spinetoram. LD 50 values for diflubenzuron were >1000 ng/μl. Also, a hazard quotient was determined and ranged from 1130.43 to 10893.27 for imidacloprid, fenpropathrin, dimethoate, and spinetoram. This quotient was mellifera 3 and 7 days after application. Spinetoram and imidacloprid were moderately toxic to A. mellifera at the recommended rates for D. citri. Diflubenzuron was not toxic to A. mellifera in the field as compared with untreated control plots. Phenoloxidase (PO) activity of A. mellifera was higher than in untreated controls when A. mellifera were exposed to 14 days old residues. The results indicate that diflubenzuron may be safe to apply in citrus when A. mellifera are foraging, while most insecticides used for management of D. citri in citrus are likely hazardous under various exposure scenarios.

  19. Characterization of a Recombinant Cathepsin B-Like Cysteine Peptidase from Diaphorina citri Kuwayama (Hemiptera: Liviidae): A Putative Target for Control of Citrus Huanglongbing.

    Science.gov (United States)

    Ferrara, Taíse Fernanda da Silva; Schneider, Vanessa Karine; Kishi, Luciano Takeshi; Carmona, Adriana Karaoglanovic; Alves, Marcio Fernando Madureira; Belasque-Júnior, Jose; Rosa, José César; Hunter, Wayne Brian; Henrique-Silva, Flávio; Soares-Costa, Andrea

    2015-01-01

    Huanglonbing (HLB) is one of the most destructive disease affecting citrus plants. The causal agent is associated with the phloem-limited bacterium Candidatus Liberibacter asiaticus (CLas) and the psyllid Diaphorina citri, vector of disease, that transmits the bacterium associated with HLB. The control of disease can be achieved by suppressing either the bacterium or the vector. Among the control strategies for HLB disease, one of the widely used consists in controlling the enzymes of the disease vector, Diaphorina citri. The insect Diaphorina citri belongs to the order Hemiptera, which frequently have cysteine peptidases in the gut. The importance of this class of enzymes led us to search for enzymes in the D. citri transcriptome for the establishment of alternatives strategies for HLB control. In this study, we reported the identification and characterization of a cathepsin B-like cysteine peptidase from D. citri (DCcathB). DCcathB was recombinantly expressed in Pichia pastoris, presenting a molecular mass of approximately 50 kDa. The enzyme hydrolyzed the fluorogenic substrate Z-F-R-AMC (Km = 23.5 μM) and the selective substrate for cathepsin B, Z-R-R-AMC (Km = 6.13 μM). The recombinant enzyme was inhibited by the cysteine protease inhibitors E64 (IC50 = 0.014 μM) and CaneCPI-4 (Ki = 0.05 nM) and by the selective cathepsin B inhibitor CA-074 (IC50 = 0.095 nM). RT-qPCR analysis revealed that the expression of the DCcathB in nymph and adult was approximately 9-fold greater than in egg. Moreover, the expression of this enzyme in the gut was 175-fold and 3333-fold higher than in the remaining tissues and in the head, respectively, suggesting that DCcathB can be a target for HLB control.

  20. Characterization of a Recombinant Cathepsin B-Like Cysteine Peptidase from Diaphorina citri Kuwayama (Hemiptera: Liviidae: A Putative Target for Control of Citrus Huanglongbing.

    Directory of Open Access Journals (Sweden)

    Taíse Fernanda da Silva Ferrara

    Full Text Available Huanglonbing (HLB is one of the most destructive disease affecting citrus plants. The causal agent is associated with the phloem-limited bacterium Candidatus Liberibacter asiaticus (CLas and the psyllid Diaphorina citri, vector of disease, that transmits the bacterium associated with HLB. The control of disease can be achieved by suppressing either the bacterium or the vector. Among the control strategies for HLB disease, one of the widely used consists in controlling the enzymes of the disease vector, Diaphorina citri. The insect Diaphorina citri belongs to the order Hemiptera, which frequently have cysteine peptidases in the gut. The importance of this class of enzymes led us to search for enzymes in the D. citri transcriptome for the establishment of alternatives strategies for HLB control. In this study, we reported the identification and characterization of a cathepsin B-like cysteine peptidase from D. citri (DCcathB. DCcathB was recombinantly expressed in Pichia pastoris, presenting a molecular mass of approximately 50 kDa. The enzyme hydrolyzed the fluorogenic substrate Z-F-R-AMC (Km = 23.5 μM and the selective substrate for cathepsin B, Z-R-R-AMC (Km = 6.13 μM. The recombinant enzyme was inhibited by the cysteine protease inhibitors E64 (IC50 = 0.014 μM and CaneCPI-4 (Ki = 0.05 nM and by the selective cathepsin B inhibitor CA-074 (IC50 = 0.095 nM. RT-qPCR analysis revealed that the expression of the DCcathB in nymph and adult was approximately 9-fold greater than in egg. Moreover, the expression of this enzyme in the gut was 175-fold and 3333-fold higher than in the remaining tissues and in the head, respectively, suggesting that DCcathB can be a target for HLB control.

  1. Effect of UV-Blocking Plastic Films on Take-Off and Host Plant Finding Ability of Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Miranda, M P; Dos Santos, F L; Felippe, M R; Moreno, A; Fereres, A

    2015-02-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a major pest of citrus worldwide due to its ability to transmit the bacteria associated with huanglongbing. Vision, behavior, and performance of insect pests can be manipulated by using ultraviolet (UV)-blocking materials. Thus, the aim of our study was to evaluate how UV-blocking plastic films may affect the take-off and host plant finding ability of D. citri. To assess the effect of a UV-deficient environment on take-off, adult psyllids were released from a vial inside a screenhouse covered by a UV-blocking or standard (control) film and the number of insects remaining on each vial under each treatment was counted at different time intervals. Moreover, to assess the ability of D. citri to find citrus plants under a UV-deficient environment, two independent no-choice host plant finding assays with different plant arrangements were conducted. In each treatment, the number of psyllids per plant at different time intervals was counted. Both D. citri take-off and host plant finding ability was clearly disrupted under a UV-deficient environment. The number of psyllids remaining in the vials was significantly higher under UV-blocking than standard film in all periods recorded. Furthermore, psyllids were present in significantly higher number on citrus plants under standard film than under UV-blocking film in all of the periods assessed and experiments conducted. Our results showed that UV-blocking materials could become a valuable strategy for integrated management of D. citri and huanglongbing in citrus grown in enclosed environments. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Talentide kooshoidmine / Jena McGregor

    Index Scriptorium Estoniae

    McGregor, Jena

    2008-01-01

    Töötajate eest hoolitsemisest, nende moraali tõstmisest ning heade töötajate hoidmisest ettevõttes majandusliku languse tingimustes. Lisa: Tegevuskava. Vt. samas: Michelle Conlin. Kuidas rasketel aegadel särada

  3. Natural parasitism of Diaphorina citri Kuwayama (Hemiptera, Psyllidae nymphs by Tamarixia radiata Waterston (Hymenoptera, Eulophidae in São Paulo orange groves Parasitismo natural de ninfas de Diaphorina citri Kuwayama (Hemiptera, Psyllidae por Tamarixia radiata Waterston (Hymenoptera, Eulophidae em pomares de laranja em São Paulo

    Directory of Open Access Journals (Sweden)

    Paulo Eduardo Branco Paiva

    2012-12-01

    Full Text Available The psyllid Diaphorina citri Kuwayama 1908 has become the main citrus pest species in the state of São Paulo, Brazil, after the introduction of the huanglongbing or citrus greening. This study evaluated the parasitism of 3rd, 4th and 5th instar D. citri nymphs by Tamarixia radiata (Waterston, 1922 in citrus groves under a regimen of regular insecticide applications in ten producing regions: Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins and São João da Boa Vista. Sixty-nine samples of new branches infested with nymphs of D. citri were collected from 2005 to 2008 in orange groves ranging from 1 to 20 years old, of the varieties Hamlin, Pera, Valencia and Natal. The parasitoid T. radiata is widely distributed in São Paulo orange groves, and was identified in 50 (72% of the samples, showing a mean parasitism rate of 12.4%. The highest parasitism rate was observed in the "summer" (from January through March, with a mean of 25.7%. Nymphal parasitism was above 90% in two samples. The probable causes of the variations in parasitism of D. citri by T. radiata are discussed.O psilídeo Diaphorina citri Kuwayama 1908 tornou-se a principal praga dos citros no estado de São Paulo após a introdução do huanglongbing ou grenning dos citros. Este estudo avaliou as proporções de ninfas de terceiro a quinto ínstares de D. citri parasitadas por Tamarixia radiata (Waterston, 1922 em pomares de laranja submetidos a pulverizações constantes de inseticidas em dez regiões produtoras, Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins e São João da Boa Vista. Foram coletadas 69 amostras de ramos jovens infestados com ninfas de D. citri obtidas entre 2005 e 2008 em pomares de 1 a 20 anos de idade, das cultivares Hamilin, Pera, Valencia e Natal. O parasitóide T. radiata encontra-se amplamente distribuído em pomares de São Paulo, tendo sido observado em 50 amostras (72%, com taxa média de

  4. Infestação de Amblyomma rotundatum (Koch (Acari, Ixodidae em sapos Bufo ictericus (Spix (Amphibia, Bufonidae: novo registro de hospedeiro Infestation of Amblyomma rotundatum (Koch (Acari, Ixodidae ticks on Bufo ictericus (Spix (Amphibia, Bufonidae: new host record

    Directory of Open Access Journals (Sweden)

    Germano Woehl Jr.

    2002-06-01

    Full Text Available Bufo ictericus Spix, 1824 toad population (N = 125 foraging in lighted areas in the Corupá Municipality, Santa Catarina State, was surveyed to evaluate the prevalence (percentage of infestation and the mean infestation intensity of Amblyomma rotundatum Koch, 1844 (Acari, Ixodidae ticks. The prevalence was of 19.2% and the mean infestation intensity was 7.4 ticks per infested toad. For the first time B. ictericus as host of A. rotundatum is reported.

  5. Community structure variability of Uropodina mites (Acari: Mesostigmata) in nests of the common mole, Talpa europaea, in Central Europe

    OpenAIRE

    Napiera?a, Agnieszka; M?dra, Anna; Leszczy?ska-Deja, Kornelia; Gwiazdowicz, Dariusz J.; Go?dyn, Bart?omiej; B?oszyk, Jerzy

    2016-01-01

    Underground nests of Talpa europaea, known as the common mole, are very specific microhabitats, which are also quite often inhabited by various groups of arthropods. Mites from the suborder Uropodina (Acari: Mesostigmata) are only one of them. One could expect that mole nests that are closely located are inhabited by communities of arthropods with similar species composition and structure. However, results of empirical studies clearly show that even nests which are close to each other can be ...

  6. First record of larvae of the water mite Hydrachna processifera Piersig, 1895 from Turkey (Acari, Hydrachnidia, Hydrachnidae

    Directory of Open Access Journals (Sweden)

    Medeni Aykut

    2018-02-01

    Full Text Available Larvae of water mite Hydrachna processifera Piersig, 1895 (Acari, Hydrachnidiae were reported on diving beetles Dytiscus marginalis Linnaeus, 1758 (Coleoptera, Dytiscidae from Turkey. The redescription of the larva was made. Earlier, the larva H. processifera was described as H. inermis, but it was subsequently synonymized with H. processifera. The larva of H. processifera is a new record for the Turkish fauna. All larvae of H. processifera were found on the mesosternum of the one specimens (prevalence = 16.7%.

  7. Citri Reticulatae Pericarpium (Chenpi): Botany, ethnopharmacology, phytochemistry, and pharmacology of a frequently used traditional Chinese medicine.

    Science.gov (United States)

    Yu, Xin; Sun, Shuang; Guo, Yuyan; Liu, Yan; Yang, Dayu; Li, Guoyu; Lü, Shaowa

    2018-06-28

    Citri Reticulatae Pericarpium (Rutaceae, CRP), commonly called as Chenpi () in Chinese, is most frequently used as a qi-regulating drug in thousands of Chinese medicine prescriptions. CRP is found mainly in major citrus-producing areas such as the Guangdong, Guangxi, Sichuan, Fujian, and Zhejiang Provinces of China. Since thousands of years in China, CRP has been used widely in clinical practice to treat nausea, vomiting, indigestion, anepithymia, diarrhea, cough, expectoration, and so on. Currently, CRP is listed in the Pharmacopoeia of the People's Republic of China. The present paper reviews the botany, ethnopharmacology, phytochemistry, pharmacology, quality control, and toxicology of CRP. Information on CRP was gathered from various sources including the books on traditional Chinese herbal medicine; scientific databases including Elsevier, PubMed, and ScienceDirect; Baidu Scholar; CNKI; and others and from different professional websites. Approximately 140 chemical compounds have been isolated and identified from CRP. Among them, volatile oils and flavonoids are generally considered as the main bioactive and characteristic ingredients. CRP possesses wide pharmacological effects such as having a beneficial effect on the cardiovascular, digestive, and respiratory systems, antitumor, antioxidant, and anti-inflammatory properties; and a protective effect on the liver and nerve. Moreover, hesperidin is chosen as an indicator in the quantitative determination of CRP, and the quantity of aflatoxin in CRP must not exceed the standard limit mentioned in the pharmacopoeia. In brief, CRP has a warming nature, and hence, it can be used in harmony with a lot of medicines. CRP not only exhibits its effects individually but also aids other medicines exhibit a better effect. CRP can be consumed with tea, food, alcohol, and medicine. Irrespective of the form it is being consumed, CRP not only shows a synergistic effect but also has strengths on its own. Modern pharmacological

  8. Global mtDNA genetic structure and hypothesized invasion history of a major pest of citrus, Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Luo, Yufa; Agnarsson, Ingi

    2018-01-01

    The Asian citrus psyllid Diaphorina citri Kuwayama is a key pest of citrus as the vector of the bacterium causing the "huanglongbing" disease (HLB). To assess the global mtDNA population genetic structure, and possible dispersal history of the pest, we investigated genetic variation at the COI gene collating newly collected samples with all previously published data. Our dataset consists of 356 colonies from 106 geographic sites worldwide. High haplotype diversity (H-mean = 0.702 ± 0.017), low nucleotide diversity (π-mean = 0.003), and significant positive selection (Ka/Ks = 32.92) were observed. Forty-four haplotypes (Hap) were identified, clustered into two matrilines: Both occur in southeastern and southern Asia, North and South America, and Africa; lineages A and B also occur in eastern and western Asia, respectively. The most abundant haplotypes were Hap4 in lineage A (35.67%), and Hap9 in lineage B (41.29%). The haplotype network identified them as the ancestral haplotypes within their respective lineages. Analysis of molecular variance showed significant genetic structure ( F ST  = 0.62, p  analysis suggests geographic structuring. We hypothesize a southern and/or southeastern Asia origin, three dispersal routes, and parallel expansions of two lineages. The hypothesized first route involved the expansion of lineage B from southern Asia into North America via West Asia. The second, the expansion of some lineage A individuals from Southeast Asia into East Asia, and the third involved both lineages from Southeast Asia spreading westward into Africa and subsequently into South America. To test these hypotheses and gain a deeper understanding of the global history of D. citri , more data-rich approaches will be necessary from the ample toolkit of next-generation sequencing (NGS). However, this study may serve to guide such sampling and in the development of biological control programs against the global pest D. citri .

  9. Structural features of PhoX, one of the phosphate-binding proteins from Pho regulon of Xanthomonas citri

    Science.gov (United States)

    Pegos, Vanessa R.; Santos, Rodrigo M. L.; Medrano, Francisco J.

    2017-01-01

    In Escherichia coli, the ATP-Binding Cassette transporter for phosphate is encoded by the pstSCAB operon. PstS is the periplasmic component responsible for affinity and specificity of the system and has also been related to a regulatory role and chemotaxis during depletion of phosphate. Xanthomonas citri has two phosphate-binding proteins: PstS and PhoX, which are differentially expressed under phosphate limitation. In this work, we focused on PhoX characterization and comparison with PstS. The PhoX three-dimensional structure was solved in a closed conformation with a phosphate engulfed in the binding site pocket between two domains. Comparison between PhoX and PstS revealed that they originated from gene duplication, but despite their similarities they show significant differences in the region that interacts with the permeases. PMID:28542513

  10. Laboratory evaluation of the effect of Beauveria bassiana on the predatory mite Phytoseiulus persimilis (Acari: Phytoseiidae).

    Science.gov (United States)

    Ullah, Mohammad Shaef; Lim, Un Taek

    2017-09-01

    Tetranychus urticae Koch (Acari: Tetranychidae), a major pest of many agricultural crops, is mainly controlled with chemical acaricides. However, predatory mites and entomopathogens have been proposed as alternative control agents. In this study, the effect of the BotaniGard ® GHA strain of Beauveria bassiana on the survival, longevity, fecundity, and egg hatch rate of the predatory mite Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) were studied under laboratory conditions. When B. bassiana was applied directly to P. persimilis eggs at a concentration of 1×10 8 conidia/ml, corrected hatchability was less than 5%, and the corrected mortality of nymphs and adults was not significantly different from control 10days after treatment. Phytoseiulus persimilis nymphs that hatched from treated eggs showed no significant change in their development time, adult female longevity, hatch rate, survival rates over time, or offspring sex ratio. However, significant negative effects on fecundity and life table parameters (net reproductive rate, intrinsic rate of natural increase, mean generation time, finite rate of increase, and doubling time) were found when B. bassiana was applied to the adult stage. Spraying B. bassiana at 1×10 8 conidia/ml on newly emerged adults of P. persimilis caused 44% reduction in the oviposition period, 26% in adult longevity, and 63% in fecundity. Due to these negative effects, B. bassiana should be used with careful adjustment of application timing (first spray B. bassiana and then release P. persimilis) to supplement biological mite control systems using P. persimilis. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Lethal and Sublethal Impacts of Acaricides on Tamarixia radiata (Hemiptera: Eulophidae), an Important Ectoparasitoid of Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Lira, A C S; Zanardi, O Z; Beloti, V H; Bordini, G P; Yamamoto, P T; Parra, J R P; Carvalho, G A

    2015-10-01

    The use of synthetic acaricides for management of pest mites may alter the efficacy of the ectoparasitoid Tamarixia radiata (Waterston) in biological control of Diaphorina citri Kuwayama, the vector of the bacteria associated with huanglongbing (HLB) in citrus orchards. We evaluated the toxicity of 16 acaricides that are recommended for the control of citrus-pest mites to T. radiata. Acrinathrin, bifenthrin, carbosulfan, and fenpropathrin caused high acute toxicity and were considered harmful (mortality >77%) to T. radiata. Abamectin, diflubenzuron, etoxazole, fenbutatin oxide, fenpyroximate, flufenoxuron, hexythiazox, propargite, spirodiclofen, and sulfur caused low acute toxicity and affected the parasitism rate and emergence rate of adults (F1 generation), and were considered slightly harmful to T. radiata. Dicofol and pyridaben did not affect the survival and action of the ectoparasitoid, and were considered harmless. In addition to its acute toxicity, carbosulfan caused mortality higher than 25% for >30 d after application, and was considered persistent. Acrinathrin, bifenthrin, fenpropathrin, fenpyroximate, propargite, and sulfur caused mortalities over 25% until 24 d after application and were considered moderately persistent; abamectin was slightly persistent, and fenbutatin oxide was short lived. Our results suggest that most acaricides used to control pest mites in citrus affect the density and efficacy of T. radiata in the biological control of D. citri. However, further evaluations are needed in order to determine the effect of these products on this ectoparasitoid under field conditions. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. First record of the genus .i.Bloszykiella./i. in Kenya with the description of .i.Bloszykiella tertia./i. sp n. (Acari: Uropodidae) from a .i.Pinus radiata./i. D. Don plantation

    Czech Academy of Sciences Publication Activity Database

    Kontschán, J.; Starý, Josef

    2015-01-01

    Roč. 56, č. 3 (2015), s. 629-635 ISSN 1681-5556 Institutional support: RVO:60077344 Keywords : Acari * new species * Pinus radiata plantation * Kenya Subject RIV: EG - Zoology Impact factor: 0.708, year: 2015

  13. Crystallization, data collection and data processing of maltose-binding protein (MalE) from the phytopathogen Xanthomonas axonopodis pv. citri

    International Nuclear Information System (INIS)

    Souza, C. S.; Ferreira, L. C. S.; Thomas, L.; Barbosa, J. A. R. G.; Balan, A.

    2009-01-01

    The Xanthomonas axonopodis pv. citri maltose-binding protein MalE has been crystallized at 293 K using the hanging-drop vapour-diffusion method. Maltose-binding protein is the periplasmic component of the ABC transporter responsible for the uptake of maltose/maltodextrins. The Xanthomonas axonopodis pv. citri maltose-binding protein MalE has been crystallized at 293 K using the hanging-drop vapour-diffusion method. The crystal belonged to the primitive hexagonal space group P6 1 22, with unit-cell parameters a = 123.59, b = 123.59, c = 304.20 Å, and contained two molecules in the asymetric unit. It diffracted to 2.24 Å resolution

  14. Influence of Tree Size and Application Rate on Expression of Thiamethoxam in Citrus and Its Efficacy Against Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Langdon, K W; Schumann, R; Stelinski, L L; Rogers, M E

    2018-04-02

    Neonicotinoids are a key group of insecticides used to manage Diaphorina citri Kuwayama (Hemiptera: Liviidae), in Florida citrus. Diaphorina citri is the vector of Candidatus Liberibacter asiaticus, the presumed causal agent of huanglongbing, a worldwide disease of citrus. A two-season field study was conducted to evaluate the effect of tree size and application rate on the expression of thiamethoxam in young citrus following application to the soil. D. citri adult and nymph abundance was also correlated with thiamethoxam titer in leaves. Tree size and application rate each significantly affected thiamethoxam titer in leaf tissue. The highest mean thiamethoxam titer observed (33.39 ppm) in small trees (mean canopy volume = 0.08 m3) occurred after application of the high rate (0.74 g Platinum 75SG per tree) tested. There was a negative correlation between both nymph and adult abundance with increasing thiamethoxam titer in leaves. A concentration of 64.63 ppm thiamethoxam was required to reach a 1% probability of encountering a flush shoot with at least one adult D. citri, while 19.05 ppm was required for the same probability of encountering nymphs. The LC90 for the field population was 7.62 ppm thiamethoxam when administered through ingestion. Exposure to dosages as low as 7.62 ppm would likely result in sublethal exposure of some proportion of the population, which could exacerbate resistance development. Based on our results, subsequent work should investigate the use of neonicotinoids by foliar rather than soil application to maintain the chemical class in future insecticide management programs in Florida citrus.

  15. Behavioral Plasticity in Probing by Diaphorina citri (Hemiptera, Liviidae): Ingestion from Phloem Versus Xylem is Influenced by Leaf Age and Surface.

    Science.gov (United States)

    Ebert, Timothy A; Backus, Elaine A; Shugart, Holly J; Rogers, Michael E

    2018-01-01

    Diaphorina citri is a major pest of citrus because it transmits Candidatus Liberibacter asiaticus, a phloem-limited bacterium that putatively causes Huanglongbing (HLB). The disease moves slowly through a tree, and the vector facilitates further within-tree movement via transmission of the pathogen. However, this only happens when D. citri stylets contact the phloem, to inoculate bacteria during phloem salivation and acquire bacteria during phloem sap ingestion. Behavioral changes in D. citri associated with different plant parts would affect how long it takes to reach phloem and how long the psyllids stays in phloem to ingest, thereby influencing the risk of disease spread. D. citri feeding was recorded on the abaxial and adaxial surfaces of mature and immature citrus leaves. Adults in the field can be found on these surfaces at all times of year. On abaxial surface of immature leaves, phloem salivation would occur after 11 h on average, but rarely as soon as 0.56 h. The corresponding values on mature leaves were 16 and 2.7. In general, psyllids spent more time ingesting phloem sap on immature leaves than on mature leaves. Psyllids on abaxial surfaces spent more time ingesting from phloem, though the strength of this effect was less than for immature versus mature leaves. In contrast, xylem ingestion increased on mature leaves compared with young. The biological differences that could produce this outcome are discussed. The results discussed herein are of relevance to further studies on the efficacy of an insecticide to act quickly enough to prevent pathogen transmission.

  16. Diel periodicity of pheromone release by females of Planococcus citri and Planococcus ficus and the temporal flight activity of their conspecific males

    Science.gov (United States)

    Levi-Zada, Anat; Fefer, Daniela; David, Maayan; Eliyahu, Miriam; Franco, José Carlos; Protasov, Alex; Dunkelblum, Ezra; Mendel, Zvi

    2014-08-01

    The diel periodicity of sex pheromone release was monitored in two mealybug species, Planococcus citri and Planococcus ficus (Hemiptera; Pseudococcidae), using sequential SPME/GCMS analysis. A maximal release of 2 ng/h pheromone by 9-12-day-old P. citri females occurred 1-2 h before the beginning of photophase. The highest release of pheromone by P. ficus females was 1-2 ng/2 h of 10-20-day-old females, approximately 2 h after the beginning of photophase. Mating resulted in termination of the pheromone release in both mealybug species. The temporal flight activity of the males was monitored in rearing chambers using pheromone baited delta traps. Males of both P. citri and P. ficus displayed the same flight pattern and began flying at 06:00 hours when the light was turned on, reaching a peak during the first and second hour of the photophase. Our results suggest that other biparental mealybug species display also diel periodicities of maximal pheromone release and response. Direct evaluation of the diel periodicity of the pheromone release by the automatic sequential analysis is convenient and will be very helpful in optimizing the airborne collection and identification of other unknown mealybug pheromones and to study the calling behavior of females. Considering this behavior pattern may help to develop more effective pheromone-based management strategies against mealybugs.

  17. Acute Toxicity of Fresh and Aged Residues of Pesticides to the Parasitoid Tamarixia radiata and to the HLB-Bacteria Vector Diaphorina citri.

    Science.gov (United States)

    Beloti, V H; Alves, G R; Moral, R A; Demétrio, C G B; Yamamoto, P T

    2018-06-01

    One method for controlling the Asian citrus psyllid (ACP) Diaphorina citri Kuwayama, the vector of the putative causal agent of Huanglongbing, uses the parasitoid Tamarixia radiata (Waterston). However, the general intensive use of insecticides has reduced the numbers of this parasitoid. This study evaluated the effect of the residual action of 24 insecticides on T. radiata and also determined the differential toxicity of insecticides to D. citri and T. radiata, using three bioassays. In the first, when adults of the parasitoid were exposed to residues of the 24 insecticides, ten were considered short-life (class 1), six slightly persistent (class 2), five moderately persistent (class 3), and three insecticides were considered persistent (class 4), under the IOBC/WPRS classification system. The second bioassay evaluated the sublethal concentrations of the persistent insecticides (formetanate, dimethoate, spinosad). Increasing the concentrations of the insecticides increased the number that were classified as persistent. In the third bioassay, evaluation of the differential toxicity of eight insecticides to the ACP and the parasitoid showed that chlorpyrifos and bifenthrin were more harmful to T. radiata. Therefore, these two insecticides are not recommended for application at the time of parasitoid release. Cypermethrin, imidacloprid, and dimethoate caused higher mortality of D. citri and are most often recommended in IPM programs. The choice of an insecticide for the control of citrus pests must be made with care, aiming to preserve the natural enemies in the ecosystem, and thereby contribute to the success of biological control.

  18. New records of water mites of the genus Atractides Koch, 1837 (Acari: Hydrachnidia, Hygrobatidae) from Thailand, Malaysia and Sulawesi (Indonesia), with the description of four new species

    NARCIS (Netherlands)

    Pesic, V.; Smit, H.

    2009-01-01

    New records of water mites of the genus Atractides Koch, 1837 (Acari: Hydrachnidia, Hygrobatidae) from Thailand, Malaysia and Sulawesi are presented. Four species new to science, Atractides siamis, A. malayensis, A. tahanensis and A. sulawesiensis, are described; a first description of the male is

  19. The Genus Ixodes (Acari: Ixodidae) in Mexico: Adult Identification Keys, Diagnoses, Hosts, and Distribution (El genero Ixodes (Acari: Ixodidae) en Mexico: claves de identificacion para adultos, diagnosis, huespedes y distribucion)

    Science.gov (United States)

    2010-01-01

    also from Estado de México (Hoffmann, 1969). Hosts in Mexico. Cricetidae and Hominidae ( Homo sapiens Linnaeus, 1758) (Mammalia) (Hoffmann, 1969...distribution El género Ixodes (Acari: Ixodidae) en México: claves de identifi cación para adultos, diagnosis, huéspedes y distribución Carmen Guzmán...postdoctoral scholarship under the Programa de Formación e Incorporación de Profesores de Carrera en Facultades y Escuelas para el Fortalecimiento de la

  20. New species and new records of mites of the genus Stigmaeus(Acari: Prostigmata: Stigmaeidae) from Crimea.

    Science.gov (United States)

    Khaustov, Alexander A

    2014-05-06

    Three new species of the genus Stigmaeus Koch, 1836 (Acari: Stigmaeidae) are described from various habitats in Crimea: Stigmaeus kuznetsovi sp. nov. from nests of Microtus socialis (Rodentia: Cricetidae); S. mitrofanovi sp. nov. from galleries of Pityogenes bistridentatus (Coleoptera: Curculionidae) under the bark of Pinus pallasiana, and S. silvestris sp. nov. from rotten log of Pinus pallasiana. Stigmaeus corticeus Kuznetsov and Wainstein, 1977 and S. maraghehiensis Bagheri and Ueckermann, 2012 are recorded for the first time in Crimea. A key to species of the genus Stigmaeus of Crimea is provided.

  1. Infection of the Gulf Coast Tick, Amblyomma Maculatum (Acari: Ixodidae), with Rickettsia Parkeri: First Report from the State of Delaware

    Science.gov (United States)

    2013-03-31

    0279276E-D761-4A27-BFF7-7329E05E0F66 Infection of the Gulf Coast tick, Amblyomma maculatum (Acari: Ixodidae), with Rickettsia parkeri: first report from...Spring, MD 20910-1230, U.S.A. Abstract The molecular detection of Rickettsia parkeri in a Gulf Coast tick, Amblyomma maculatum, collected in Delaware...near Smyrna, Delaware. All specimens were tested for the presence of Rickettsia with a genus-specific quantitative real-time polymerase chain

  2. Voluntary Falling in Spider Mites in Response to Different Ecological Conditions at Landing Points

    OpenAIRE

    Ohzora, Yousuke; Yano, Shuichi

    2011-01-01

    We examined voluntary-falling behaviour by adult females of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) and one of its major predators Neoseiulus californicus McGregor (Acari: Phytoseiidae). Experiments were conducted using a setup in which mites could only move onto one of two landing points by falling. Significantly more T. urticae females fell onto available food leaves compared to non-food or heavily infested leaves, whereas significantly fewer females fell...

  3. Mass distribution and spatial organization of the linear bacterial motor of Spiroplasma citri R8A2.

    Science.gov (United States)

    Trachtenberg, Shlomo; Andrews, S Brian; Leapman, Richard D

    2003-03-01

    In the simple, helical, wall-less bacterial genus Spiroplasma, chemotaxis and motility are effected by a linear, contractile motor arranged as a flat cytoskeletal ribbon attached to the inner side of the membrane along the shortest helical line. With scanning transmission electron microscopy and diffraction analysis, we determined the hierarchical and spatial organization of the cytoskeleton of Spiroplasma citri R8A2. The structural unit appears to be a fibril, approximately 5 nm wide, composed of dimers of a 59-kDa protein; each ribbon is assembled from seven fibril pairs. The functional unit of the intact ribbon is a pair of aligned fibrils, along which pairs of dimers form tetrameric ring-like repeats. On average, isolated and purified ribbons contain 14 fibrils or seven well-aligned fibril pairs, which are the same structures observed in the intact cell. Scanning transmission electron microscopy mass analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified cytoskeletons indicate that the 59-kDa protein is the only constituent of the ribbons.

  4. Expression, purification, crystallization and preliminary X-ray analysis of YaeQ (XAC2396) from Xanthomonas axonopodis pv. citri

    International Nuclear Information System (INIS)

    Guzzo, Cristiane R.; Nagem, Ronaldo A. P.; Galvão-Botton, Leonor M. P.; Guimarães, Beatriz G.; Medrano, Francisco J.; Barbosa, João A. R. G.; Farah, Chuck S.

    2005-01-01

    The first crystallographic study of a member of the YaeQ family of proteins, which are conserved in a small group of Gram-negative bacteria, most of which are animal or plant pathogens, is reported. Diffraction data were collected to 1.9 Å resolution and an interpretable electron-density map was obtained. Xanthomonas axonopodis pv. citri YaeQ (XAC2396) is a member of a family of bacterial proteins conserved in several Gram-negative pathogens. Here, the cloning, expression, purification and crystallization of the 182-residue (20.6 kDa) YaeQ protein are described. Recombinant YaeQ containing selenomethionine was crystallized in space group P2 1 and crystals diffracted to 1.9 Å resolution at a synchrotron source. The unit-cell parameters are a = 39.75, b = 91.88, c = 48.03 Å, β = 108.37°. The calculated Matthews coefficient suggests the presence of two YaeQ molecules in the asymmetric unit. Initial experimental phases were calculated by the multiple-wavelength anomalous dispersion technique and an interpretable electron-density map was obtained

  5. 3-Nitropropionic acid production by the endophytic Diaporthe citri: Molecular taxonomy, chemical characterization, and quantification under pH variation.

    Science.gov (United States)

    Polonio, Julio Cesar; Ribeiro, Marcos Alessandro Dos Santos; Rhoden, Sandro Augusto; Sarragiotto, Maria Helena; Azevedo, João Lúcio; Pamphile, João Alencar

    2016-12-01

    3-nitropropionic acid (3-NPA) is a nitrogenated compound produced by plants and fungi and has been associated with poisoning episodes in humans, animals, and to induction of Huntington disease symptoms in rats. The production of 3-NPA by endophytes has been reported, but the function and biosynthesis are not well-defined. The specie of endophytic strain G-01 was confirmed as Diaporthe citri using a multilocus sequence analysis, and was verified different concentrations of 3-NPA produced at different initial pHs by these strain. The chemical analysis indicated that 3-NPA was the majority compound present in the crude extracts. The better extraction condition was at an initial pH of 7.0 for 22 d, yielding about 80 % of 3-NPA per mg of extract. It was observed that the concentration of 3-NPA increased after the initial consumption of reduction sugars, indicating that the compound is produced after the high energetic production phase of the fungus. These and other studies demonstrate the production of this compound by plants and endophytic fungi, indicating that 3-NPA may be involved in defence and nutrition systems of endophytes and host plants, and they also might participate in the biogeochemical nitrogen cycle. Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  6. Oral delivery of double-stranded RNAs induces mortality in nymphs and adults of the Asian citrus psyllid, Diaphorina citri.

    Directory of Open Access Journals (Sweden)

    Diogo Manzano Galdeano

    Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri Kuwayama, is one of the most important citrus pests. ACP is the vector of the phloem-limited bacteria Candidatus Liberibacter americanus and Candidatus Liberibacter asiaticus, the causal agents of the devastating citrus disease huanglongbing (HLB. The management of HLB is based on the use of healthy young plants, eradication of infected plants and chemical control of the vector. RNA interference (RNAi has proven to be a promising tool to control pests and explore gene functions. Recently, studies have reported that target mRNA knockdown in many insects can be induced through feeding with double-stranded RNA (dsRNA. In the current study, we targeted the cathepsin D, chitin synthase and inhibitor of apoptosis genes of adult and nymph ACP by feeding artificial diets mixed with dsRNAs and Murraya paniculata leaves placed in dsRNAs solutions, respectively. Adult ACP mortality was positively correlated with the amount of dsRNA used. Both nymphs and adult ACP fed dsRNAs exhibited significantly increased mortality over time compared with that of the controls. Moreover, qRT-PCR analysis confirmed the dsRNA-mediated RNAi effects on target mRNAs. These results showed that RNAi can be a powerful tool for gene function studies in ACP and perhaps for HLB control.

  7. Diaphorina citri Induces Huanglongbing-Infected Citrus Plant Volatiles to Repel and Reduce the Performance of Propylaea japonica.

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    Lin, Yongwen; Lin, Sheng; Akutse, Komivi S; Hussain, Mubasher; Wang, Liande

    2016-01-01

    Transmission of plant pathogens through insect vectors is a complex biological process involving interactions between the host plants, insects, and pathogens. Simultaneous impact of the insect damage and pathogenic bacteria in infected host plants induce volatiles that modify not only the behavior of its insect vector but also of their natural enemies, such as parasitoid wasps. Therefore, it is essential to understand how insects such as the predator ladybird beetle responds to volatiles emitted from a host plant and how the disease transmission alters the interactions between predators, vector, pathogens, and plants. In this study, we investigated the response of Propylaea japonica to volatiles from citrus plants damaged by Diaphorina citri and Candidatus Liberibacter asiaticus through olfactometer bioassays. Synthetic chemical blends were also used to determine the active compounds in the plant volatile. The results showed that volatiles emitted by healthy plants attracted more P. japonica than other treatments, due to the presence of high quantities of D-limonene and beta-ocimene, and the lack of methyl salicylate. When using synthetic chemicals in the olfactory tests, we found that D-limonene attracted P. japonica while methyl salicylate repelled the predator. However, beta-ocimene attracted the insects at lower concentrations but repelled them at higher concentrations. These results indicate that P. japonica could not efficiently search for its host by using volatile cues emitted from psyllids- and Las bacteria-infected citrus plants.

  8. Oral delivery of double-stranded RNAs induces mortality in nymphs and adults of the Asian citrus psyllid, Diaphorina citri.

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    Galdeano, Diogo Manzano; Breton, Michèle Claire; Lopes, João Roberto Spotti; Falk, Bryce W; Machado, Marcos Antonio

    2017-01-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is one of the most important citrus pests. ACP is the vector of the phloem-limited bacteria Candidatus Liberibacter americanus and Candidatus Liberibacter asiaticus, the causal agents of the devastating citrus disease huanglongbing (HLB). The management of HLB is based on the use of healthy young plants, eradication of infected plants and chemical control of the vector. RNA interference (RNAi) has proven to be a promising tool to control pests and explore gene functions. Recently, studies have reported that target mRNA knockdown in many insects can be induced through feeding with double-stranded RNA (dsRNA). In the current study, we targeted the cathepsin D, chitin synthase and inhibitor of apoptosis genes of adult and nymph ACP by feeding artificial diets mixed with dsRNAs and Murraya paniculata leaves placed in dsRNAs solutions, respectively. Adult ACP mortality was positively correlated with the amount of dsRNA used. Both nymphs and adult ACP fed dsRNAs exhibited significantly increased mortality over time compared with that of the controls. Moreover, qRT-PCR analysis confirmed the dsRNA-mediated RNAi effects on target mRNAs. These results showed that RNAi can be a powerful tool for gene function studies in ACP and perhaps for HLB control.

  9. Analyses of Mitogenome Sequences Revealed that Asian Citrus Psyllids (Diaphorina citri) from California Were Related to Those from Florida.

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    Wu, Fengnian; Kumagai, Luci; Cen, Yijing; Chen, Jianchi; Wallis, Christopher M; Polek, MaryLou; Jiang, Hongyan; Zheng, Zheng; Liang, Guangwen; Deng, Xiaoling

    2017-08-31

    Asian citrus psyllid (ACP, Diaphorina citri Kuwayama) transmits "Candidatus Liberibacter asiaticus" (CLas), an unculturable alpha-proteobacterium associated with citrus Huanglongbing (HLB). CLas has recently been found in California. Understanding ACP population diversity is necessary for HLB regulatory practices aimed at reducing CLas spread. In this study, two circular ACP mitogenome sequences from California (mt-CApsy, ~15,027 bp) and Florida (mt-FLpsy, ~15,012 bp), USA, were acquired. Each mitogenome contained 13 protein coding genes, 2 ribosomal RNA and 22 transfer RNA genes, and a control region varying in sizes. The Californian mt-CApsy was identical to the Floridian mt-FLpsy, but different from the mitogenome (mt-GDpsy) of Guangdong, China, in 50 single nucleotide polymorphisms (SNPs). Further analyses were performed on sequences in cox1 and trnAsn regions with 100 ACPs, SNPs in nad1-nad4-nad5 locus through PCR with 252 ACP samples. All results showed the presence of a Chinese ACP cluster (CAC) and an American ACP cluster (AAC). We proposed that ACP in California was likely not introduced from China based on our current ACP collection but somewhere in America. However, more studies with ACP samples from around the world are needed. ACP mitogenome sequence analyses will facilitate ACP population research.

  10. Morphological abnormalities and cell death in the Asian citrus psyllid (Diaphorina citri) midgut associated with Candidatus Liberibacter asiaticus.

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    Ghanim, Murad; Fattah-Hosseini, Somayeh; Levy, Amit; Cilia, Michelle

    2016-09-15

    Candidatus Liberibacter asiaticus (CLas) is a phloem-limited, gram-negative, fastidious bacterium that is associated with the development of citrus greening disease, also known as Huanglongbing (HLB). CLas is transmitted by the Asian citrus psyllid (ACP) Diaphorina citri, in a circulative manner. Two major barriers to transmission within the insect are the midgut and the salivary glands. We performed a thorough microscopic analysis within the insect midgut following exposure to CLas-infected citrus trees. We observed changes in nuclear architecture, including pyknosis and karyorrhexis as well as changes to the actin cytoskeleton in CLas-exposed midgut cells. Further analyses showed that the changes are likely due to the activation of programmed cell death as assessed by Annexin V staining and DNA fragmentation assays. These results suggest that exposure to CLas-infected trees induces apoptotic responses in the psyllid midgut that should be further investigated. Understanding the adaptive significance of the apoptotic response has the potential to create new approaches for controlling HLB.

  11. Acaricidal and repellent activities of essential oil of Eucalyptus globulus against Dermanyssus gallinae (Acari: Mesostigmata

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    Dehghani-Samani Amir

    2015-07-01

    Full Text Available Introduction: By considering an increase in drug resistance against red mites, finding the nonchemical herbal acaricide against Dermanyssus gallinae (De Geer (Acari: Mesostigmata is necessary to kill them and to reduce the chemical resistance against chemical acaricides in this specie. Dermanyssus gallinae is a potential vector of the causal agent of several viral diseases such as Equine encephalitis and St. Louis encephalitis. It can be a vector of bacteria such as Salmonella spp., Mycobacterium spp. and Erysipelothrix rhusiopathiae. It is also known to cause itching dermatosis in humans. In this study acaricidal and repellent activities of essential oil of Eucalyptus globulus against Dermanyssus gallinae were studied. Methods: After extracting the essential oil, different concentrations of the plant extract were prepared. Then, acaricidal effect of different concentrations was tested on poultry red mite, Dermanyssus gallinae, by dropping 3-4 drops of essential oil on mites. Repellent activity of essential oil was tested by Y-tube olfactometer bioassay. After the test, total number of killed and repellent mites reported. Results: Concentration of 1:2 or 50% had more acaricidal effect on mites. Also essential oil of Eucalyptus globulus had repellent activity against red mites. Conclusion: This study showed that essential oil of Eucalyptus globulus had acaricidal and repellent activities against red mites. Hence it might be used as a herbal acaricide against it to kill and to reduce the chemical resistance in this specie.

  12. Ticks (Acari: Ixodidae of livestock and their seasonal activities, northwest of Iran

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    Zahra Ramezani

    2014-09-01

    Full Text Available Objective: To identify the ticks (Acari: Ixodidae of livestock and their seasonal activities, in northwest of Iran, including the combination of two of the geographical regions of Iran (Caspian and mountain plateau where the majority of the domestic ruminants in Iran exist. Methods: Fifteen villages of Meshkin-Shahr County were selected randomly from different areas of the county. The animal dwellings were visited and the whole body of sheep, cows, goats and dogs were examined for their probable infestation. Samples were identified at the level of species according to the standard morphological key. Results: In this study 1 208 specimen were collected and totally nine species (Dermacentor marginatus, Dermacentor niveus, Haemaphysalis erinacei, Haemaphysalis punctata, Hyalomma anatolicum, Hyalomma asiaticum, Hyalomma marginatum, Rhipicephalus bursa and Rhipicephalus sanguineus were identified in this study. Also 569 host including 40 cows, 450 sheep, 70 goats and 9 dogs were examined for infestation and among them 255 were infested which showed a 44% of infestation among examined livestock. The infestation rate among sheep (46% was higher than other hosts. The infestation rates among the rest of hosts were as: cows (40%, goat (37% and dogs (33%. Conclusions: The results of this study and other studies of the region showed the probability of the establishment and development of the burden of several tick-borne diseases.

  13. Study of Acari and Collembola Populations in Four Cultivation Systems in Dourados - MS

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    Rosilda Mara Mussury

    2002-09-01

    Full Text Available The impact four cultivation systems on the soil fauna was studied, using Oribatida and Gamasida acarids as bioindicators and collembolan. The research was carried out in experimental fields, located in EMBRAPA - CPAO in Dourados, Centerwest of Brazil from July 1997 to December 1999. The constant pasture system presented smaller impact on the soil fauna followed by agricultural cattle rotation and a direct plantation system. In the conventional plantation series, the populational density of the mesofauna organisms was low, especially collembolan families.O impacto de quatro sistemas de cultivo sobre a fauna de solo foram estudados, utilizando-se como bioindicadores os acari Oribatida e Gamasida e os Collembola. A pesquisa foi conduzida em campos experimentais, localizados na EMBRAPA - CPAO no município de Dourados, MS, no período de julho de 1997 à dezembro de 1999. O sistema de pastagem contínua apresentou menor impacto sobre a fauna de solo seguido da rotação agricultura pecuária e do sistema de plantio direto. Nas sucessões do plantio convencional, a densidade populacional dos organismos da mesofauna foi baixa, em especial as famílias de colembolos.

  14. Rickettsia parkeri and "Candidatus Rickettsia andeanae" in Questing Amblyomma maculatum (Acari: Ixodidae) From Mississippi.

    Science.gov (United States)

    Lee, J K; Moraru, G M; Stokes, J V; Wills, R W; Mitchell, E; Unz, E; Moore-Henderson, B; Harper, A B; Varela-Stokes, A S

    2017-03-01

    Amblyomma maculatum Koch (Acari: Ixodidae), the primary vector for Rickettsia parkeri, may also be infected with a rickettsia of unknown pathogenicity, "Candidatus Rickettsia andeanae." Infection rates with these rickettsiae vary geographically, and coinfected ticks have been reported. In this study, infection rates of R. parkeri and "Ca. R. andeanae" were evaluated, and rickettsial DNA levels quantified, in 335 questing adult A. maculatum collected in 2013 (n = 95), 2014 (n = 139), and 2015 (n = 101) from Oktibbeha County, MS. Overall infection rates of R. parkeri and "Ca. R. andeanae" were 28.7% and 9.3%, respectively, with three additional A. maculatum (0.9%) coinfected. While R. parkeri-infected ticks were detected all three years (34.7% in 2013; 13.7% in 2014; 43.6% in 2015), "Ca. R. andeanae" was not detected in 2013, and was detected at rates of 10.8% in 2014, and 15.8% in 2015. Interestingly, rickettsial DNA levels in singly-infected ticks were significantly lower in "Ca. R. andeanae"-infected ticks compared to R. parkeri-infected ticks (P Rickettsia species in A. maculatum at the population level. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Biology, ecology and control of the Penthaleus species complex (Acari: Penthaleidae).

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    Umina, Paul A; Hoffmann, Ary A; Weeks, Andrew R

    2004-01-01

    Blue oat mites, Penthaleus spp. (Acari: Penthaleidae), are major agricultural pests in southern Australia and other parts of the world, attacking various pasture, vegetable and crop plants. Management of these mites has been complicated by the recent discovery of three cryptic pest species of Penthaleus, whereas prior research had assumed a single species. The taxonomy, population genetics, ecology, biology and control of the Penthaleus spp. complex are reviewed. Adult Penthaleus have a dark blue-black body approximately 1 mm in length, and eight red-orange legs. Within Australia, they are winter pests completing two or three generations a season, depending on conditions. The summer is passed as diapausing eggs, when long-distance dispersal is thought to occur. The Penthaleus spp. reproduce by thelytokous parthenogenesis, with populations comprising clones that differ ecologically. The three pest Penthaleus spp. differ markedly in their distributions, plant hosts, timing of diapause egg production and response to pesticides, highlighting the need to develop control strategies that consider each species separately. Chemicals are the main weapons used in current control programs, however research continues into alternative more sustainable management options. Host plant resistance, crop rotations, conservation of natural enemies, and improved timing of pesticide application would improve the management of these pests. The most cost-effective and environmentally acceptable means of control will result from the integration of these practices combined with the development of a simple field-based kit to distinguish the different mite species.

  16. Cuticle expansion during feeding in the tick Amblyomma hebraeum (Acari: Ixodidae): The role of hydrostatic pressure.

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    Kaufman, W Reuben; Kaufman, S; Flynn, Peter C

    2016-05-01

    Female Amblyomma hebraeum ticks (Acari: Ixodidae) increase their weight ∼10-fold during a 'slow phase of engorgement' (7-9 days), and a further 10-fold during the 'rapid phase' (12-24h). During the rapid phase, the cuticle thins by half, with a plastic (permanent) deformation of greater than 40% in two orthogonal directions. A stress of 2.5 MPa or higher is required to achieve this degree of deformation (Flynn and Kaufman, 2015). Using a dimensional analysis of the tick body and applying the Laplace equation, we calculated that the tick must achieve high internal hydrostatic pressures in order to engorge fully: greater than 55 kPa at a fed:unfed mass ratio of ∼20:1, when cuticle thinning commences (Flynn and Kaufman, 2011). In this study we used a telemetric pressure transducer system to measure the internal hydrostatic pressure of ticks during feeding. Sustained periods of irregular high frequency (>20 Hz) pulsatile bursts of high pressure (>55 kPa) were observed in two ticks: they had been cannulated just prior to the rapid phase of engorgement, and given access to a host rabbit for completion of the feeding cycle. The pattern of periods of high pressure generation varied over the feeding cycle and between the two specimens. We believe that these pressures exceed those reported so far for any other animal. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Essential oils of aromatic Egyptian plants repel nymphs of the tick Ixodes ricinus (Acari: Ixodidae).

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    El-Seedi, Hesham R; Azeem, Muhammad; Khalil, Nasr S; Sakr, Hanem H; Khalifa, Shaden A M; Awang, Khalijah; Saeed, Aamer; Farag, Mohamed A; AlAjmi, Mohamed F; Pålsson, Katinka; Borg-Karlson, Anna-Karin

    2017-09-01

    Due to the role of Ixodes ricinus (L.) (Acari: Ixodidae) in the transmission of many serious pathogens, personal protection against bites of this tick is essential. In the present study the essential oils from 11 aromatic Egyptian plants were isolated and their repellent activity against I. ricinus nymphs was evaluated Three oils (i.e. Conyza dioscoridis L., Artemisia herba-alba Asso and Calendula officinalis L.) elicited high repellent activity in vitro of 94, 84.2 and 82%, respectively. The most active essential oil (C. dioscoridis) was applied in the field at a concentration of 6.5 µg/cm 2 and elicited a significant repellent activity against I. ricinus nymphs by 61.1%. The most repellent plants C. dioscoridis, C. officinalis and A. herba-alba yielded essential oils by 0.17, 0.11 and 0.14%, respectively. These oils were further investigated using gas chromatography-mass spectrometry analysis. α-Cadinol (10.7%) and hexadecanoic acid (10.5%) were the major components of C. dioscoridis whereas in C. officinalis, α-cadinol (21.2%) and carvone (18.2%) were major components. Artemisia herba-alba contained piperitone (26.5%), ethyl cinnamate (9.5%), camphor (7.7%) and hexadecanoic acid (6.9%). Essential oils of these three plants have a potential to be used for personal protection against tick bites.

  18. Aggregation in the tick Ixodes ricinus (Acari: Ixodidae): use and reuse of questing vantage points.

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    Healy, John A E; Bourke, Patrick

    2008-03-01

    Ongoing work in oak woods in Killarney National Park in southwestern Ireland is focusing on the factors influencing the fine-scale aggregated distribution of Ixodes ricinus L. (Acari: Ixodidae) on the ground. The extent of reuse of stems of vegetation as questing points by adult ticks was determined by paint-marking stems on which ticks were found, counting and removing these ticks, and subsequently reexamining the same stems for ticks on two further occasions. Overall, an estimated 2,967 stems in 123 separate rush plants (Juncus effusus L.) were examined. Statistical analysis of the data demonstrated a highly significant reoccupancy by ticks of stems previously and recently used. Furthermore, it is shown that the extent of stem reuse by ticks is significantly and positively correlated with the numbers of ticks originally observed on those stems. Although other factors may be involved in generating clumping of ticks, the results are compatible with the proposition that aggregation of I. ricinus on the ground is pheromone-mediated. The findings are discussed in relation to what is known about the powers of lateral movement of I. ricinus on the ground and the possible implications for the performance of tick traps.

  19. Morphometric variations of laelapine mite (Acari: Mesostigmata populations infesting small mammals (Mammalia in Brazil

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    F. Martins-Hatano

    Full Text Available The goal of this study was to evaluate the morphometric variation of laelapine populations (Acari, Mesostigmata associated with neotropical oryzomyine rodents at different geographic localities in Brazil. Three nominal mite species were selected for study, all infesting the pelage of small mammals at different localities in Rio de Janeiro, Espírito Santo, Bahia, and the Federal District, Brazil. To analyse morphometric characteristics, thirty-seven morphological characters distributed across the whole body of each specimen were measured. We use the Analysis of Principal Components, extracting the three first axes and projecting each mite in these axes. Major species level changes in the taxonomy of the host mammals allows an independent examination of morphometric variation of mites infesting a set of distinctly different host species at different geographic localities. Gigantolaelaps vitzthumi and Laelaps differens are associated with oryzomyine rodents of the genus Cerradomys, and consistently showed a tendency to cluster by host phylogeny. Laelaps manguinhosi associated with Nectomys rattus in central Brazil is morphometrically distinct from mites infesting N. squamipes in the coastal restingas of Rio de Janeiro and Espírito Santo. The results obtained here indicate that laelapine mite populations can vary among geographic areas and among phylogenetically related host species. Clearly, the study of these mites at the population level can be an important tool for clarifying the taxonomy of both mites and hosts.

  20. Morphometric variations of laelapine mite (Acari: Mesostigmata) populations infesting small mammals (Mammalia) in Brazil.

    Science.gov (United States)

    Martins-Hatano, F; Gettinger, D; Manhães, M L; Bergallo, H G

    2012-08-01

    The goal of this study was to evaluate the morphometric variation of laelapine populations (Acari, Mesostigmata) associated with neotropical oryzomyine rodents at different geographic localities in Brazil. Three nominal mite species were selected for study, all infesting the pelage of small mammals at different localities in Rio de Janeiro, Espírito Santo, Bahia, and the Federal District, Brazil. To analyse morphometric characteristics, thirty-seven morphological characters distributed across the whole body of each specimen were measured. We use the Analysis of Principal Components, extracting the three first axes and projecting each mite in these axes. Major species level changes in the taxonomy of the host mammals allows an independent examination of morphometric variation of mites infesting a set of distinctly different host species at different geographic localities. Gigantolaelaps vitzthumi and Laelaps differens are associated with oryzomyine rodents of the genus Cerradomys, and consistently showed a tendency to cluster by host phylogeny. Laelaps manguinhosi associated with Nectomys rattus in central Brazil is morphometrically distinct from mites infesting N. squamipes in the coastal restingas of Rio de Janeiro and Espírito Santo. The results obtained here indicate that laelapine mite populations can vary among geographic areas and among phylogenetically related host species. Clearly, the study of these mites at the population level can be an important tool for clarifying the taxonomy of both mites and hosts.

  1. Comparison of thermal activity thresholds of the spider mite predators Phytoseiulus macropilis and Phytoseiulus persimilis (Acari: Phytoseiidae).

    Science.gov (United States)

    Coombs, Megan R; Bale, Jeffrey S

    2013-04-01

    The lower and upper thermal activity thresholds of the predatory mite Phytoseiulus macropilis Banks (Acari: Phytoseiidae) were compared with those of its prey Tetranychus urticae Koch (Acari: Tetranychidae) and one of the alternative commercially available control agents for T. urticae, Phytoseiulus persimilis Athias-Henriot. Adult female P. macropilis retained ambulatory function (CTmin) and movement of appendages (chill coma) at significantly lower temperatures (8.2 and 0.4 °C, respectively) than that of P. persimilis (11.1 and 3.3 °C) and T. urticae (10.6 and 10.3 °C). As the temperature was raised, P. macropilis ceased walking (CTmax) and entered heat coma (42.7 and 43.6 °C), beyond the upper locomotory limits of P. persimilis (40.0 and 41.1 °C), but before T. urticae (47.3 and 48.7 °C). Walking speeds were investigated and P. persimilis was found to have significantly faster ambulation than P. macropilis and T. urticae across a range of temperatures. The lower thermal activity threshold data indicate that P. macropilis will make an effective biological control agent in temperate climates.

  2. Ricoseius loxocheles (Acari: Phytoseiidae) is not a predator of false spider mite on coffee crops: What does it eat?

    Science.gov (United States)

    Vacacela Ajila, Henry E; Ferreira, João A M; Colares, Felipe; Oliveira, Cleber M; Bernardo, Ana Maria G; Venzon, Madelaine; Pallini, Angelo

    2018-01-01

    Ricoseius loxocheles (De Leon) (Acari: Phytoseiidae) is often found in coffee crops and is known to feed on coffee leaf rust, Hemileia vastatrix Berkeley and Broome (Uredinales). As the occurrence of coffee leaf rust is limited primarily to the rainy season, the mite may use other food sources to survive during the periods of low pathogen prevalence. It is well known that phytoseiid mites can survive on a variety of food sources, such as herbivorous mites, fungi and pollen. We evaluated the ability of R. loxocheles to survive and reproduce on a diet of Brevipalpus phoenicis Geijskes (Acari: Tenuipalpidae), cattail pollen (Typha spp.), clover rust (Puccinia oxalidis), bee pollen (Santa Bárbara ® dehydrated pollen, Santa Bárbara, MG, Brazil) and coffee leaf rust. Ricoseius loxocheles did not survive or reproduce on any B. phoenicis stages tested (egg, larva, adult). The survival and oviposition of R. loxocheles were directly affected by the presence of coffee rust urediniospores, but not by the presence of the prey. Survival and oviposition of the phytoseiid were similar when fed cattail pollen, clover rust and coffee leaf rust but was lower when fed bee pollen. Our results show that R. loxocheles is not a predator of B. phoenicis but it is able to utilize other resources besides coffee leaf rust.

  3. Patogenicidade de Beauveria bassiana ao psilídeo Diaphorina citri e compatibilidade do fungo com produtos fitossanitários

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    Ana Paula Ferreira Pinto

    2012-12-01

    Full Text Available O objetivo deste trabalho foi avaliar a patogenicidade de Beauveria bassiana a ninfas de Diaphorina citri (Hemiptera: Psyllidae e verificar a compatibilidade do fungo com produtos fitossanitários e sua persistência em plantas de citros. Ninfas de D. citri foram pulverizadas com B. bassiana, nas concentrações 5x10(6, 1x10(7, 5x10(7, 1x10(8, 5x10(8 e 1x10(9 conídios mL-1, para determinação da concentração letal. Para avaliação da compatibilidade do fungo com produtos fitossanitários, extrato de nim e cinco inseticidas de quatro grupos químicos diferentes foram incorporados individualmente ao meio de cultura BDA em que o fungo foi cultivado. Avaliaram-se o crescimento vegetativo, a esporulação e a viabilidade do entomopatógeno. Plantas de citros, mantidas em casa de vegetação, foram tratadas primeiramente com os produtos fitossanitários e depois com o entomopatógeno. Avaliaram-se os tempos de exposição de 24 horas e de 7 e 14 dias. O fungo foi patogênico às ninfas de D. citri; a CL50 foi de 0,4x10(7 e a CL90 de 6,7x10(7 conidios mL-1, no décimo dia de avaliação. Em laboratório, os produtos fitosssanitários reduzem o crescimento do fungo. Em casa de vegetação, os produtos não afetam a sobrevivência do fungo nas plantas de citros.

  4. DIVERSIDAD GENÉTICA DE Diaphorina citri EN CULTIVOS CÍTRICOS DEL VALLE DEL CAUCA Y QUINDÍO (COLOMBIA

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    MIGUEL ANGEL MONCAYO-DONOSO

    Full Text Available El psílido asiático Diaphorina citri es el principal vector de la bacteria Candidatus Liberibacter que causa la enfermedad Huanglongbing, considerada devastadora en la citricultura mundial y aún no reportada en Colombia. La variabilidad genética poblacional de D. citri fue estudiadautilizando la técnica de secuenciación del gen COI mitocondrial como marcador molecular. Se realizaron colectas de adultos en zonas productoras de cítricos del Valle del Cauca y el Quindío. La amplificación se realizó con dos parejas de cebadores específicos para hemípteros. Los productos de la PCR fueron secuenciados en Macrogen-Korea obteniéndose un total de 124 secuencias. En el análisis bioinformático se utilizaron los programas Vector NTI 11.5, Arlequín V 3.5, MEGA 5 y MAFFT 6. Los índices de diversidad molecular fueron similares entre poblaciones, mostrando un mismo origen, separación reciente de poblaciones y que no existe diferenciación genética significativa que pueda albergar variantes de la bacteria; sin embargo, el índice de diversidad haplotípica fue más alto que el de diversidad nucleotídica y este último índice presentó bajo número de sitios polimórficos, indicando que las poblaciones de D. citri están en expansión. El estudio de la variabilidad genética del vector representa una herramienta para predecir escenarios probables de propagación de la enfermedad.

  5. Overview of worldwide diversity of Diaphorina citri Kuwayama mitochondrial cytochrome oxidase 1 haplotypes: two Old World lineages and a New World invasion

    Science.gov (United States)

    Boykin, L.M.; De Barro, P.; Hall, D.G.; Hunter, W.B.; McKenzie, C.L.; Powell, C.A.; Shatters, R.G.

    2012-01-01

    Relationships among worldwide collections of Diaphorina citri (Asian citrus psyllid) were analyzed using mitochondrial cytochrome oxidase I (mtCOI) haplotypes from novel primers. Sequences were produced from PCR amplicons of an 821bp portion of the mtCOI gene using D. citri specific primers, derived from an existing EST library. An alignment was constructed using 612bps of this fragment and consisted of 212 individuals from 52 collections representing 15 countries. There were a total of eight polymorphic sites that separated the sequences into eight different haplotypes (Dcit-1 through Dcit-8). Phylogenetic network analysis using the statistical parsimony software, TCS, suggests two major haplotype groups with preliminary geographic bias between southwestern Asia (SWA) and southeastern Asia (SEA). The recent (within the last 15 to 25 years) invasion into the New World originated from only the SWA group in the northern hemisphere (USA and Mexico) and from both the SEA and SWA groups in the southern hemisphere (Brazil). In only one case, Reunion Island, did haplotypes from both the SEA and SWA group appear in the same location. In Brazil, both groups were present, but in separate locations. The Dcit-1 SWA haplotype was the most frequently encountered, including ~50% of the countries sampled and 87% of the total sequences obtained from India, Pakistan and Saudi Arabia. The second most frequently encountered haplotype, Dcit-2, the basis of the SEA group, represented ~50% of the countries and contained most of the sequences from Southeast Asia and China. Interestingly, only the Caribbean collections (Puerto Rico and Guadeloupe) represented a unique haplotype not found in other countries, indicating no relationship between the USA (Florida) and Caribbean introductions. There is no evidence for cryptic speciation for D. citri based on the COI region included in this study. PMID:22717059

  6. Cloning and expressing a highly functional and substrate specific farnesoic acid o-methyltransferase from the Asian citrus psyllid (Diaphorina citri Kuwayama).

    Science.gov (United States)

    Van Ekert, Evelien; Shatters, Robert G; Rougé, Pierre; Powell, Charles A; Smagghe, Guy; Borovsky, Dov

    2015-01-01

    The Asian citrus psyllid, Diaphorina citri, transmits a phloem-limited bacterium, Candidatus 'Liberibacter' asiaticus that causes citrus greening disease. Because juvenile hormone (JH) plays an important role in adult and nymphal development, we studied the final steps in JH biosynthesis in D. citri. A putative JH acid methyltransferase ortholog gene (jmtD) and its cognate cDNA were identified by searching D. citri genome database. Expression analysis shows expression in all life stages. In adults, it is expressed in the head-thorax, (containing the corpora allata), and the abdomen (containing ovaries and male accessory glands). A 3D protein model identified the catalytic groove with catalytically active amino acids and the S-adenosyl methionine (SAM)-binding loop. The cDNA was expressed in Escherichia coli cells and the purified enzyme showed high preference for farnesoic acid (FA) and homoFA (kcat of 0.752 × 10(-3) and 0.217 × 10(-3) s(-1), respectively) as compared to JH acid I (JHA I) (cis/trans/cis; 2Z, 6E, 10cis), JHA III (2E, 6E, 10cis), and JHA I (trans/cis/cis; 2E, 2Z, 10cis) (kcat of 0.081 × 10(-3), 0.013 × 10(-3), and 0.003 × 10(-3) s(-1), respectively). This suggests that this ortholog is a DcFA-o-methyl transferase gene (fmtD), not a jmtD, and that JH biosynthesis in D. citri proceeds from FA to JH III through methyl farnesoate (MF). DcFA-o-MT does not require Ca(2+), Mg(2+) or Zn(2+), however, Zn(2+) (1 mM) completely inhibits the enzyme probably by binding H115 at the active groove. This represents the first purified FA-o-MT from Hemiptera with preferred biological activity for FA and not JHA.

  7. Suppression of greasy spot disease caused by Mycosphaerella citri Whiteside on grapefruit trees in an organic orchard using an aqueous organic mixture of composted cornmeal, humic acid, molasses, and fish oil vs vegetable oil

    Science.gov (United States)

    Greasy spot disease of citrus, caused by the fungus Mycosphaerella citri Whiteside, afflicts citrus trees in all citrus-growing areas of the United States, eastern Mexico, Central America, and the Caribbean islands, causing premature defoliation, blemished fruit, and reduced tree vigor, yield, and f...

  8. RNA interference of two glutathione S-transferase genes, Diaphorina citri DcGSTe2 and DcGSTd1, increases the susceptibility of Asian citrus psyllid (Hemiptera: Liviidae) to the pesticides fenpropathrin and thiamethoxam.

    Science.gov (United States)

    Yu, Xiudao; Killiny, Nabil

    2018-03-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama, is an important agricultural pest of citrus globally. Foliar application of chemical insecticides is the most widely used option for reducing D. citri populations. Knockdown of glutathione S-transferase (GST) in several insect species leads to increased susceptibility to insecticides; however, information about the detoxifying role of GST genes in D. citri is unavailable. Via a sequence homology search, we isolated and characterized three DcGST genes (DcGSTd1, DcGSTe1 and DcGSTe2) from D. citri. Phylogenetic analysis grouped DcGSTd1 into the delta class of GST genes, whereas DcGSTe1 and DcGSTe2 were clustered in the epsilon clade. Gene expression analysis revealed that chlorpyrifos treatment increased the mRNA levels of DcGSTe1 and fenpropathrin enhanced the expression level of DcGSTd1, while DcGSTe2 was significantly up-regulated after exposure to thiamethoxam at a dose of 30% lethal concentration (LC30). RNA interference (RNAi) of DcGSTe2 and DcGSTd1 followed by an insecticide bioassay increased the mortalities of thiamethoxam-treated psyllids by 23.0% and fenpropathrin-treated psyllids by 15.0%. In contrast, knockdown of DcGSTe1 did not significantly increase the susceptibility of D. citri to any of these three insecticides. Further, feeding with double-stranded RNA (dsDcGSTe2-d1) interfusion co-silenced DcGSTe2 and DcGSTd1 expression in D. citri, and led to an increase of susceptibility to both fenpropathrin and thiamethoxam. The findings suggest that DcGSTe2 and DcGSTd1 play unique roles in detoxification of the pesticides thiamethoxam and fenpropathrin. In addition, co-silencing by creating a well-designed dsRNA interfusion against multiple genes was a good RNAi strategy in D. citri. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. [Rapid Identification of Epicarpium Citri Grandis via Infrared Spectroscopy and Fluorescence Spectrum Imaging Technology Combined with Neural Network].

    Science.gov (United States)

    Pan, Sha-sha; Huang, Fu-rong; Xiao, Chi; Xian, Rui-yi; Ma, Zhi-guo

    2015-10-01

    To explore rapid reliable methods for detection of Epicarpium citri grandis (ECG), the experiment using Fourier Transform Attenuated Total Reflection Infrared Spectroscopy (FTIR/ATR) and Fluorescence Spectrum Imaging Technology combined with Multilayer Perceptron (MLP) Neural Network pattern recognition, for the identification of ECG, and the two methods are compared. Infrared spectra and fluorescence spectral images of 118 samples, 81 ECG and 37 other kinds of ECG, are collected. According to the differences in tspectrum, the spectra data in the 550-1 800 cm(-1) wavenumber range and 400-720 nm wavelength are regarded as the study objects of discriminant analysis. Then principal component analysis (PCA) is applied to reduce the dimension of spectroscopic data of ECG and MLP Neural Network is used in combination to classify them. During the experiment were compared the effects of different methods of data preprocessing on the model: multiplicative scatter correction (MSC), standard normal variable correction (SNV), first-order derivative(FD), second-order derivative(SD) and Savitzky-Golay (SG). The results showed that: after the infrared spectra data via the Savitzky-Golay (SG) pretreatment through the MLP Neural Network with the hidden layer function as sigmoid, we can get the best discrimination of ECG, the correct percent of training set and testing set are both 100%. Using fluorescence spectral imaging technology, corrected by the multiple scattering (MSC) results in the pretreatment is the most ideal. After data preprocessing, the three layers of the MLP Neural Network of the hidden layer function as sigmoid function can get 100% correct percent of training set and 96.7% correct percent of testing set. It was shown that the FTIR/ATR and fluorescent spectral imaging technology combined with MLP Neural Network can be used for the identification study of ECG and has the advantages of rapid, reliable effect.

  10. Metabolic alterations in the nymphal instars of Diaphorina citri induced by Candidatus Liberibacter asiaticus, the putative pathogen of huanglongbing.

    Directory of Open Access Journals (Sweden)

    Nabil Killiny

    Full Text Available Currently, huanglongbing is the most damaging disease of citrus causing huge economic losses. The disease is caused by the Gram-negative bacterium Candidatus Liberibacter asiaticus (CLas. The pathogen is transmitted in a persistent propagative circulative manner within its vector, the Asian citrus psyllid, Diaphorina citri. Exploring the metabolic alteration in the vector may lead to a better understanding of the nutritional needs of CLas and to designing an artificial medium for culturing the pathogen. It has been shown that the nymphal stages have a greater role in transmission mainly because they feed on plants more actively than adults. In this study, we carried out an untargeted comparative metabolomic analysis for healthy and CLas-infected 4th / 5th instar nymphs. The metabolic analysis was performed using trimethylsilylation and methyl chloroformate derivatization followed by Gas Chromatography-Mass Spectrometry (GC-MS. Overall, the changes in the nymph metabolism due to the infection with CLas were more pronounced than in adults, as we previously published. Nymphs reared on CLas-infected Valencia sweet orange were higher in many metabolites, mainly those of the TCA cycle, C16 and C18 fatty acids, glucose, sucrose, L-proline, L-serine, pyroglutamic acid, saccharic acid, threonic acid and myo-inositol than those reared on healthy plants. In contrast, CLas-infected nymphs were lower in putrescine, glycine, L -phenylalanine, L -tyrosine, L -valine, and chiro-inositol. The information provided from this study may contribute in acceleration of the availability of CLas in culture and consequent screening of antibacterial compounds to discover a definitive solution for huanglongbing.

  11. Impact of different temperatures on survival and energy metabolism in the Asian citrus psyllid, Diaphorina citri Kuwayama.

    Science.gov (United States)

    El-Shesheny, Ibrahim; Hijaz, Faraj; El-Hawary, Ibrahim; Mesbah, Ibrahim; Killiny, Nabil

    2016-02-01

    Temperature influences the life history and metabolic parameters of insects. Asian citrus psyllid (ACP), Diaphorina citri is a tropical and subtropical pest. ACP invaded new regions around the world and threatened the citrus industry as a vector for Huanglongbing (HLB) disease. ACP is widely distributed and can survive high (up to 45 °C) and low temperatures (as low as -6 °C). The precise mechanism of temperature tolerance in ACP is poorly understood. We investigated adult survival, cellular energy balance, gene expression, and nucleotide and sugar-nucleotide changes under the effect of different temperature regimes (0 °C to 45 °C with 5 °C intervals). The optimum temperatures for survival were 20 and 25 °C. Low temperatures of 0 °C and 5 °C caused 50% mortality after 2 and 4 days respectively, while one day at high temperature (40 °C and 45 °C) caused more than 95% mortality. The lowest quantity of ATP (3.69 ± 1.6 ng/insect) and the maximum ATPase enzyme activities (57.43 ± 7.6 μU/insect) were observed at 25 °C. Correlation between ATP quantities and ATPase activity was negative. Gene expression of hsp 70, V-type proton ATPase catalytic subunit A and ATP synthase α subunit matched these results. Twenty-four nucleotides and sugar-nucleotides were quantified using HPLC in ACP adults maintained at low, high, and optimum temperatures. The nucleotide profiles were different among treatments. The ratios between AMP:ATP and ADP:ATP were significantly decreased and positively correlated to adults survival, whereas the adenylate energy charge was increased in response to low and high temperatures. Exploring energy metabolic regulation in relation with adult survival might help in understanding the physiological basis of how ACP tolerates newly invaded regions. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Metabolic alterations in the nymphal instars of Diaphorina citri induced by Candidatus Liberibacter asiaticus, the putative pathogen of huanglongbing.

    Science.gov (United States)

    Killiny, Nabil; Jones, Shelley E

    2018-01-01

    Currently, huanglongbing is the most damaging disease of citrus causing huge economic losses. The disease is caused by the Gram-negative bacterium Candidatus Liberibacter asiaticus (CLas). The pathogen is transmitted in a persistent propagative circulative manner within its vector, the Asian citrus psyllid, Diaphorina citri. Exploring the metabolic alteration in the vector may lead to a better understanding of the nutritional needs of CLas and to designing an artificial medium for culturing the pathogen. It has been shown that the nymphal stages have a greater role in transmission mainly because they feed on plants more actively than adults. In this study, we carried out an untargeted comparative metabolomic analysis for healthy and CLas-infected 4th / 5th instar nymphs. The metabolic analysis was performed using trimethylsilylation and methyl chloroformate derivatization followed by Gas Chromatography-Mass Spectrometry (GC-MS). Overall, the changes in the nymph metabolism due to the infection with CLas were more pronounced than in adults, as we previously published. Nymphs reared on CLas-infected Valencia sweet orange were higher in many metabolites, mainly those of the TCA cycle, C16 and C18 fatty acids, glucose, sucrose, L-proline, L-serine, pyroglutamic acid, saccharic acid, threonic acid and myo-inositol than those reared on healthy plants. In contrast, CLas-infected nymphs were lower in putrescine, glycine, L -phenylalanine, L -tyrosine, L -valine, and chiro-inositol. The information provided from this study may contribute in acceleration of the availability of CLas in culture and consequent screening of antibacterial compounds to discover a definitive solution for huanglongbing.

  13. Innate and Conditioned Responses to Chemosensory and Visual Cues in Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae, Vector of Huanglongbing Pathogens

    Directory of Open Access Journals (Sweden)

    Joseph M. Patt

    2014-11-01

    Full Text Available Asian citrus psyllid (Diaphorina citri transmits Huanglongbing, a devastating disease that threatens citrus trees worldwide. A better understanding of the psyllid’s host-plant selection process may lead to the development of more efficient means of monitoring it and predicting its movements. Since behavioral adaptations, such as associative learning, may facilitate recognition of suitable host-plants, we examined whether adult D. citri could be conditioned to visual and chemosensory stimuli from host and non-host-plant sources. Response was measured as the frequency of salivary sheaths, the residue of psyllid probing activity, in a line of emulsified wax on the surface of a test arena. The psyllids displayed both appetitive and aversive conditioning to two different chemosensory stimuli. They could also be conditioned to recognize a blue-colored probing substrate and their response to neutral visual cues was enhanced by chemosensory stimuli. Conditioned psyllids were sensitive to the proportion of chemosensory components present in binary mixtures. Naïve psyllids displayed strong to moderate innate biases to several of the test compounds. While innate responses are probably the psyllid’s primary behavioral mechanism for selecting host-plants, conditioning may enhance its ability to select host-plants during seasonal transitions and dispersal.

  14. Simultaneous quantification of coumarins, flavonoids and limonoids in Fructus Citri Sarcodactylis by high performance liquid chromatography coupled with diode array detector.

    Science.gov (United States)

    Chu, Jun; Li, Song-Lin; Yin, Zhi-Qi; Ye, Wen-Cai; Zhang, Qing-Wen

    2012-07-01

    A high performance liquid chromatography coupled with diode array detector (HPLC-DAD) method was developed for simultaneous quantification of eleven major bioactive components including six coumarins, three flavonoids and two limonoids in Fructus Citri Sarcodactylis. The analysis was performed on a Cosmosil 5 C(18)-MS-II column (4.6 mm × 250 mm, 5 μm) with water-acetonitrile gradient elution. The method was validated in terms of linearity, sensitivity, precision, stability and accuracy. It was found that the calibration curves for all analytes showed good linearity (R(2)>0.9993) within the test ranges. The overall limit of detection (LOD) and limit of quantification (LOQ) were less than 3.0 and 10.2 ng. The relative standard deviations (RSDs) for intra- and inter-day repeatability were not more than 4.99% and 4.92%, respectively. The sample was stable for at least 48 h. The spike recoveries of eleven components were 95.1-104.9%. The established method was successfully applied to determine eleven components in three samples from different locations. The results showed that the newly developed HPLC-DAD method was linear, sensitive, precise and accurate, and could be used for quality control of Fructus Citri Sarcodactylis. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Delivery of dsRNA through topical feeding for RNA interference in the citrus sap piercing-sucking hemipteran, Diaphorina citri.

    Science.gov (United States)

    Killiny, Nabil; Kishk, Abdelaziz

    2017-06-01

    RNA interference (RNAi) is a powerful means to study functional genomics in insects. The delivery of dsRNA is a challenging step in the development of RNAi assay. Here, we describe a new delivery method to increase the effectiveness of RNAi in the Asian citrus psyllid Diaphorina citri. Bromophenol blue droplets were topically applied to fifth instar nymphs and adults on the ventral side of the thorax between the three pairs of legs. In addition to video recordings that showed sucking of the bromophenol blue by the stylets, dissected guts turned blue indicating that the uptake was through feeding. Thus, we called the method topical feeding. We targeted the abnormal wing disc gene (awd), also called nucleoside diphosphate kinase (NDPK), as a reporter gene to prove the uptake of dsRNA via this method of delivery. Our results showed that dsRNA-awd caused reduction of awd expression and nymph mortality. Survival and lifespan of adults emerged from treated nymphs and treated adults were affected. Silencing awd caused wing malformation in the adults emerged from treated nymphs. Topical feeding as a delivery of dsRNA is highly efficient for both nymphs and adults. The described method could be used to increase the efficiency of RNAi in D. citri and other sap piercing-sucking hemipterans. © 2017 Wiley Periodicals, Inc.

  16. Innate and Conditioned Responses to Chemosensory and Visual Cues in Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae), Vector of Huanglongbing Pathogens.

    Science.gov (United States)

    Patt, Joseph M; Stockton, Dara; Meikle, William G; Sétamou, Mamoudou; Mafra-Neto, Agenor; Adamczyk, John J

    2014-11-19

    Asian citrus psyllid (Diaphorina citri) transmits Huanglongbing, a devastating disease that threatens citrus trees worldwide. A better understanding of the psyllid's host-plant selection process may lead to the development of more efficient means of monitoring it and predicting its movements. Since behavioral adaptations, such as associative learning, may facilitate recognition of suitable host-plants, we examined whether adult D. citri could be conditioned to visual and chemosensory stimuli from host and non-host-plant sources. Response was measured as the frequency of salivary sheaths, the residue of psyllid probing activity, in a line of emulsified wax on the surface of a test arena. The psyllids displayed both appetitive and aversive conditioning to two different chemosensory stimuli. They could also be conditioned to recognize a blue-colored probing substrate and their response to neutral visual cues was enhanced by chemosensory stimuli. Conditioned psyllids were sensitive to the proportion of chemosensory components present in binary mixtures. Naïve psyllids displayed strong to moderate innate biases to several of the test compounds. While innate responses are probably the psyllid's primary behavioral mechanism for selecting host-plants, conditioning may enhance its ability to select host-plants during seasonal transitions and dispersal.

  17. Infection Density Dynamics of the Citrus Greening Bacterium “Candidatus Liberibacter asiaticus” in Field Populations of the Psyllid Diaphorina citri and Its Relevance to the Efficiency of Pathogen Transmission to Citrus Plants

    Science.gov (United States)

    Ukuda-Hosokawa, Rie; Sadoyama, Yasutsune; Kishaba, Misaki; Kuriwada, Takashi; Anbutsu, Hisashi

    2015-01-01

    Huanglongbing, or citrus greening, is a devastating disease of citrus plants recently spreading worldwide, which is caused by an uncultivable bacterial pathogen, “Candidatus Liberibacter asiaticus,” and vectored by a phloem-sucking insect, Diaphorina citri. We investigated the infection density dynamics of “Ca. Liberibacter asiaticus” in field populations of D. citri with experiments using field-collected insects to address how “Ca. Liberibacter asiaticus” infection density in the vector insect is relevant to pathogen transmission to citrus plants. Of 500 insects continuously collected from “Ca. Liberibacter asiaticus”-infected citrus trees with pathological symptoms in the spring and autumn of 2009, 497 (99.4%) were “Ca. Liberibacter asiaticus” positive. The infections were systemic across head-thorax and abdomen, ranging from 103 to 107 bacteria per insect. In spring, the infection densities were low in March, at ∼103 bacteria per insect, increasing up to 106 to 107 bacteria per insect in April and May, and decreasing to 105 to 106 bacteria per insect in late May, whereas the infection densities were constantly ∼106 to 107 bacteria per insect in autumn. Statistical analysis suggested that several factors, such as insect sex, host trees, and collection dates, may be correlated with “Ca. Liberibacter asiaticus” infection densities in field D. citri populations. Inoculation experiments with citrus seedlings using field-collected “Ca. Liberibacter asiaticus”-infected insects suggested that (i) “Ca. Liberibacter asiaticus”-transmitting insects tend to exhibit higher infection densities than do nontransmitting insects, (ii) a threshold level (∼106 bacteria per insect) of “Ca. Liberibacter asiaticus” density in D. citri is required for successful transmission to citrus plants, and (iii) D. citri attaining the threshold infection level transmits “Ca. Liberibacter asiaticus” to citrus plants in a stochastic manner. These

  18. Repellent activities of dichloromethane extract of Allium sativum (garlic) (Liliaceae) against Hyalomma rufipes (Acari).

    Science.gov (United States)

    Nchu, Felix; Magano, Solomon R; Eloff, Jacobus N

    2016-12-02

    Dichloromethane (DCM) extract of garlic (Allium sativum Linn.) bulbs was assessed for its repellent effect against the hard tick, Hyalomma rufipes (Acari: Ixodidae) using two tick behavioural bioassays; Type A and Type B repellency bioassays, under laboratory conditions. These bioassays exploit the questing behaviour of H. rufipes, a tick that in nature displays ambush strategy, seeking its host by climbing up on vegetation and attaching to a passing host. One hundred microlitres (100 µL) of the test solution containing DCM extract of garlic bulbs and DCM at concentrations of 0.35%, 0.7% or 1.4% w/v were evaluated. DCM only was used for control. Tick repellency increased significantly (R2 = 0.98) with increasing concentration (40.03% - 86.96%) yielding an EC50 of 0.45% w/v in Type B repellency bioassay. At concentration of 1.4% w/v, the DCM extract of garlic bulbs produced high repellency index of 87% (male ticks) and 87.5% (female ticks) in the Type A repellency bioassay. Only 4% avoidance of male ticks or female ticks was recorded in the Type B repellency bioassay. In the corresponding controls, the mean numbers of non-repelled male or female ticks were 80% and 41 males or 38 females of 50 ticks in the Type A and Type B repellency bioassays, respectively. The variations in the results could be attributed to the difference in tick repellent behaviours that were assessed by the two repellency bioassays; the Type A repellency bioassay assessed repellent effect of garlic extracts without discriminating between deterrence and avoidance whereas the Type B repellency bioassay only assessed avoidance response. Generally, DCM extract of garlic was repellent against H. rufipes, albeit weak tick repellency was obtained in the Type B repellency bioassay. Furthermore, this study established that the tick repellent activity of garlic extracts is predominantly by deterrence.

  19. Effects of Insecticides and Fungicides Commonly Used in Tomato Production on Phytoseiulus persimilis (Acari: Phtyoseiidae).

    Science.gov (United States)

    Ditillo, J L; Kennedy, G G; Walgenbach, J F

    2016-12-01

    The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is an important pest of tomatoes in North Carolina. Resident populations of the predatory mite Phytoseiulus persimilis have recently been detected on field-grown tomatoes in central North Carolina, and potentially can be a useful biological control agent against T. urticae Laboratory bioassays were used to assess lethal and reproductive effects of 10 insecticides and five fungicides commonly used in commercial tomato production (chlorantraniliprole, spinetoram, permethrin, imidacloprid, dimethoate, dinotefuran, thiamethoxam, bifenthrin, fenpropathrin, lambda-cyhalothrin, azoxystrobin, chlorothalonil, boscalid, cyazofamid, and mancozeb) on P. persimilis adult females and eggs. Insecticides were tested using concentrations equivalent to 1×, 0.5×, and 0.1× of the recommended field rates. Fungicides were tested at the 1× rate only. Dimethoate strongly impacted P. persimilis with high adult mortality, reduced fecundity, and reduced hatch of eggs laid by treated adults, particularly at high concentrations. The pyrethroids lambda-cyhalothrin, bifenthrin, and fenpropathrin were associated with repellency and reproductive effects at high concentrations. Bifenthrin additionally caused increased mortality at high concentrations. Chlorantraniliprole, dinotefuran, and permethrin did not significantly affect mortality or reproduction. Imidacloprid significantly reduced fecundity and egg viability, but was not lethal to adult P. persimilis Thiamethoxam negatively impacted fecundity at the 1× rate. There were no negative effects associated with fungicide exposure with the exception of mancozeb, which impacted fecundity. Field trials were conducted to explore the in vivo impacts of screened insecticides on P. persimilis populations in the field. Field trials supported the incompatibility of dimethoate with P. persimilis populations. © The Authors 2016. Published by Oxford University Press on behalf

  20. Intercropping Allium tuberosum Rottler ex Sprengel (Amaryllidaceae reduces Tetranychus urticae Koch (Acari: Tetranychidae populations in strawberry

    Directory of Open Access Journals (Sweden)

    Fernando Hata

    2017-12-01

    Efeito do cultivo consorciado de Allium tuberosum Rottlerex Sprengel(Amaryllidaceae em populações de Tetranychus urticae Koch (Acari: Tetranychidae em morangueiro Resumo. O ácaro-rajado, Tetranychus urticae Koch, é uma das mais importantes pragas em casas de vegetação no mundo. Foi avaliado o efeito do consórcio de cebolinha chinesa, cultivada sob as estruturas de madeira que suportam as sacolas para o cultivo de morangueiro (sistema suspenso, em duas casas de vegetação, entre novembro de 2016 e janeiro de 2017. Formas móveis e ovos de ácaros foram contabilizados em folhas de morangueiro. Para as avaliações, cinco plantas foram aleatoriamente selecionadas em cada parcela. Populações de ácaro-rajado em folhas de morangueiro foram avaliadas com lupa de bolso, com 10 x de aumento. Reduções foram observadas em três de oito avaliações de formas móveis de ácaro-rajado. Foram observadas reduções no número de ovos em uma avaliação. Tomando em consideração os dados de ácaros acumulados por dia, foi observado que o consórcio reduziu em 54% a população de ácaros. Por outro lado, o número de ovos não foi alterado.

  1. Effect of Pollen from Different Plant Species on Development of Typhlodromus pyri (Sheuten (Acari: Phytoseiidae Efecto del Polen de Diferentes Especies Vegetales sobre el Desarrollo de Typhlodromus pyri (Sheuten (Acari: Phytoseiidae

    Directory of Open Access Journals (Sweden)

    Paulina Bermúdez

    2010-09-01

    Full Text Available Typhlodromus pyri (Sheuten (Acari: Phytoseiidae is a phytoseiid mite with a high potential in controlling the false Chilean mite (Brevipalpus chilensis Baker; Acari: Tenuipalpidae. The purpose of this study was to determine the effect of different plant species pollen as a complementary food in the development of T. pyri when its prey is in low levels of availability. Mites were individually placed on black plastic boxes with pollen and maintained at a temperature of 26 ± 2 °C, 70 ± 5% relative humidity (RH, and a photoperiod of 16:8 h (L:D. Postembryonic development of T. pyri was studied in 11 pollen species, as well as in a mixed diet of Hirschfeldia incana (L. and B. chilensis. Results show that H. incana was the only pollen in which there was no mortality (P > 0.05 along with the control (Oxalis pes-caprae L.. Mean duration from egg to adult with H. incana was 8.70 ± 1.66 d, protonymph 3.27 ± 0.21 d, and deutonymph 2.90 ± 1.45 d (P > 0.05. The mix feeding of T. pyri did not show any significant differences neither in the mean time from egg to adult, nor in mortality by feeding only with B. chilensis. Survival curves of T. pyri fed only with H. incana pollen, combined with B. chilensis, and only with B. chilensis are higher in the first 14 d of life. The sex ratio was not significantly affected by being fed only with H. incana pollen, B. chilensis, or by a combination of both.Typhlodromus pyri (Sheuten (Acari: Phytoseiidae es un ácaro que presenta un alto potencial de uso para el control de la falsa arañita roja de la vid (Brevipalpus chilensis Baker; Acari: Tenuipalpidae. El objetivo de este estudio fue determinar el efecto del polen de diferentes especies vegetales como alimento complementario para T. pyri cuando escasea su presa. Los parámetros post-embrionarios de T. pyri se estudiaron en 11 especies de polen, en una dieta mixta de polen de Hirschfeldia incana (L. y B. chilensis. Los ácaros se colocaron individualmente sobre

  2. Acari; Tetranychidae

    African Journals Online (AJOL)

    *Corresponding author; E-mail: eziahvin@yahoo.com ... on the Karate®-resistant population showed that the application of these products 1 h before treatment with. Karate® reduce ... tissue, as well as a reduced photosynthetic rate ... Piraneo (2013) was employed to determine ..... toxicity in Norwegian populations of T.

  3. TAMBO VIEJO: UN ASENTAMIENTO FORTIFICADO EN EL VALLE DE ACARÍ, PERÚ (Tambo Viejo: A Fortified Settlement in the Acari Valley, Peru

    Directory of Open Access Journals (Sweden)

    Lidio M. Valdez

    2013-10-01

    Full Text Available La aparición de los asentamientos fortificados y el origen del conflicto violento son temas poco discutidos en el contexto de la arqueología peruana. Considero que es oportuno investigar y determinar cuándo y por qué surgieron los primeros asentamientos fortificados. El propósito central de este artículo está precisamente orientado a responder tales interrogantes y discutir el tema del conflicto violento en el valle de Acarí y, por extensión, en la costa sur del Perú. Las evidencias arqueológicas disponibles señalan que, durante el periodo Intermedio Temprano, Tambo Viejo fue un asentamiento defendido por varias estructuras perimétricas. Otros sitios contemporáneos de Tambo Viejo en Acarí también fueron fortificados. Además, existe en el mismo valle evidencia tangible de violencia en la forma de prisioneros que posteriormente fueron decapitados. En contraste a la evidencia proveniente de Acarí, no existen asentamientos del periodo Intermedio Temprano identificables como fortificaciones, lo que hace de los sitios de Acarí los primeros asentamientos fortificados de toda la costa sur. ENGLISH: The emergence of violent conflict and of fortified settlements is a subject little studied within Peruvian archaeology. However, I consider it vital to investigate and determine the time and the reasons under which fortified settlements were first established. The central aim of this paper is to discuss when and why fortified settlements emerged first in the Acari Valley and, by extension, in the south coast of Peru. Available archaeological evidence indicates that during the Early Intermediate Period, Tambo Viejo was a fortified settlement protected by several massive walls. Other neighbouring sites in Acari were also fortified. Furthermore, in Acari there is conclusive evidence for violence in the form of decapitated individuals. In contrast to evidence coming from Acari, not a single Early Intermediate Period settlement from other

  4. Harşit Vadisi’nin (Türkiye) Caligonellid Akarları (Acari: Raphignathoidea: Caligonellidae)

    OpenAIRE

    DOĞAN, Sibel; DOĞAN, Salih; ERMAN, Orhan

    2018-01-01

    Bu çalışmada, Harşit Vadisi’nden (Türkiye) toplanancaligonellid akarların (Acari: Caligonellidae) iki cinsine ait toplam dört türtespit edildi. Türlerden üçü, Caligonellahumilis (Koch), Neognathusspectabilis (Summers ve Schlinger) ve N.terrestris (Summers ve Schlinger), çalışma alanından ilk defa kaydedildi.Bu türlerin, çeşitli organlarının şekilleri çizildi, ölçümleri alındı vetanımları yapıldı. Ayrıca Türkiye’de ve dünyada yayılışları üzerinde duruldu....

  5. Comparing chemical and biological control strategies for twospotted spider mites (Acari: Tetranychidae) in commercial greenhouse production of bedding plants.

    Science.gov (United States)

    Opit, George P; Perret, Jamis; Holt, Kiffnie; Nechols, James R; Margolies, David C; Williams, Kimberly A

    2009-02-01

    Efficacy, costs, and impact on crop salability of various biological and chemical control strategies for Tetranychus urticae Koch (Acari: Tetranychidae) were evaluated on mixed plantings of impatiens, Impatiens wallerana Hook.f (Ericales: Balsaminaceae), and ivy geranium, Pelargonium peltatum (1.) L'Hér. Ex Aiton (Geraniales: Geraniaceae), cultivars in commercial greenhouses. Chemical control consisting of the miticide bifenazate (Floramite) was compared with two biological control strategies using the predatory mite Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae). Treatments were 1) a single, early application of bifenazate; 2) a single, early release of predatory mites at a 1:4 predator:pest ratio based on leaf samples to estimate pest density; 3) a weekly release of predatory mites at numbers based on the area covered by the crop; and 4) an untreated control. T. urticae populations were monitored for 3 wk after the earliest treatment. When plants were ready for market, their salability was estimated. Bifenazate and density-based P. persimilis treatments effectively reduced T. urticae numbers starting 1 wk after plants had been treated, whereas the scheduled, area-based P. persimilis treatment had little or no effect. The percentage of flats that could be sold at the highest market wholesale price ranged from 15 to 33%, 44 to 86%, 84 to 95%, and 92 to 100%, in the control, weekly area-based P. persimilis, bifenazate, and single density-based P. persimilis treatments, respectively. We have shown that in commercial greenhouse production of herbaceous ornamental bedding plants, estimating pest density to determine the appropriate number of predators to release is as effective and offers nearly the same economic benefit as prophylactic use of pesticides.

  6. Identification of Three Kinds of Citri Reticulatae Pericarpium Based on Deoxyribonucleic Acid Barcoding and High-performance Liquid Chromatography-diode Array Detection-electrospray Ionization/Mass Spectrometry/Mass Spectrometry Combined with Chemometric Analysis

    Science.gov (United States)

    Yu, Xiaoxue; Zhang, Yafeng; Wang, Dongmei; Jiang, Lin; Xu, Xinjun

    2018-01-01

    Background: Citri Reticulatae Pericarpium is the dried mature pericarp of Citrus reticulata Blanco which can be divided into “Chenpi” and “Guangchenpi.” “Guangchenpi” is the genuine Chinese medicinal material in Xinhui, Guangdong province; based on the greatest quality and least amount, it is most expensive among others. Hesperidin is used as the marker to identify Citri Reticulatae Pericarpium described in the Chinese Pharmacopoeia 2010. However, both “Chenpi” and “Guangchenpi” contain hesperidin so that it is impossible to differentiate them by measuring hesperidin. Objective: Our study aims to develop an efficient and accurate method to separate and identify “Guangchenpi” from other Citri Reticulatae Pericarpium. Materials and Methods: The genomic deoxyribonucleic acid (DNA) of all the materials was extracted and then the internal transcribed spacer 2 was amplified, sequenced, aligned, and analyzed. The secondary structures were created in terms of the database and website established by Jörg Schultz et al. High-performance liquid chromatography-diode array detection-electrospray Ionization/mass spectrometry (HPLC-DAD-ESI-MS)/MS coupled with chemometric analysis was applied to compare the differences in chemical profiles of the three kinds of Citri Reticulatae Pericarpium. Results: A total of 22 samples were classified into three groups. The results of DNA barcoding were in accordance with principal component analysis and hierarchical cluster analysis. Eight compounds were deduced from HPLC-DAD-ESI-MS/MS. Conclusions: This method is a reliable and effective tool to differentiate the three Citri Reticulatae Pericarpium. SUMMARY The internal transcribed spacer 2 regions and the secondary structure among three kinds of Citri Reticulatae Pericarpium varied considerablyAll the 22 samples were analyzed by high-performance liquid chromatography (HPLC) to obtain the chemical profilesPrincipal component analysis and hierarchical cluster analysis

  7. A novel disease affecting the predatory mite Phytoseiulus persimilis (Acari, Phytoseiidae): 1. Symptoms in adult females.

    Science.gov (United States)

    Schütte, Conny; Kleijn, Prisca W; Dicke, Marcel

    2006-01-01

    Adult female Phytoseiulus persimilis Athias-Henriot (Acari, Phytoseiidae) of one of our laboratory populations showed a lower degree of attraction to herbivore-induced plant volatiles than other laboratory populations. We hypothesized earlier that this consistent change in foraging behavior is a symptom of a disease, as it is a contagious phenomenon. Here we describe more symptoms by comparing mated females of this population (non-responding (NR) population) with mated females of other populations that are strongly attracted to herbivore-induced plant volatiles (responding populations). The most apparent characteristic of the NR population was the presence of numerous dorso-ventrally flattened females (76% of all females). These females had a normal size after mating but shrank during adulthood. Independent of their age, shrunken females did not reproduce and died a few days after shrinking. In addition to these profound differences in short term performance, females from the NR-population showed behavioral changes, including a lower degree of attraction to herbivore-induced plant volatiles, a higher tendency to leave a prey-patch and a lower predation rate. Moreover, about half of the live females of the NR-population carried birefringent dumbbell-shaped crystals in the legs whereas live females of a responding population carried crystals only in the lumen of the Malpighian tubules and the rectum. The symptom 'crystals in the legs' was correlated with low reproduction. Energy dispersive X-ray diffraction of these crystals revealed that they contain calcium and phosphorus along with carbon and oxygen. Crystals with comparable elemental compositions and the same characteristic concentric layering are well known in insects, where they are thought to play a major role in detoxification of calcium and heavy metals, and in storage of phosphorus. The fraction of predators carrying a white spot in the distal part of the opisthosoma, due to accumulation of excretory

  8. Ticks (Acari: Ixodidae as ectoparasites of Brazilian wild birds and their association with rickettsial diseases

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    Maria Ogrzewalska

    2016-04-01

    Full Text Available Os carrapatos (Acari: Ixodoidea são ectoparasitas obrigatórias de uma variedade de hospedeiros vertebrados e têm um papel importante na ecologia e transmissão de diversos patógenos causadores de doenças em humanos e animais no mundo todo. No Brasil existem 68 espécies de carrapatos e pelo menos 23 espécies são encontradas parasitando aves silvestres. Esse número tem crescido com o advento de novos estudos ressaltando o papel das aves nos ciclos de vida desses artrópodes. Na América do Sul alguns desses carrapatos estão envolvidos na epidemiologia de doenças graves para o ser humano, como a febre maculosa, causada por bactérias do gênero Rickettsia (Rickettsiales: Rickettsiaceae. O alvo desse artigo é apresentar o estado atual de conhecimento sobre a fauna de carrapatos encontrados em aves no Brasil e as associações estabelecidas com as riquetsioses. A literatura disponível sobre carrapatos em aves e ocorrência de riquétsias foi revisada e pôde ser concluído que aves têm um papel importante nos ciclos de vida de várias espécies de carrapatos, sendo especialmente importantes para os estágios imaturos (larvas e ninfas. A maior parte do conhecimento sabrecai na fauna de carrapatos de aves dos biomas Mata Atlântica e Cerrado no sudeste e centro-oeste do Brasil. Já o conhecimento sobre o parasitismo por carrapatos em aves dos outros biomas: Amazônia, Caatinga, Pantanal e Pampas é muito limitado. Além disso, não há estudos sobre o papel de aves como disseminadores de carrapatos entre áreas e também o papel de aves no ciclo de Rickettsia não está totalmente esclarecido.

  9. Impacts of Horticultural Mineral Oils and Two Insecticide Practices on Population Fluctuation of Diaphorina citri and Spread of Huanglongbing in a Citrus Orchard in Sarawak

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    Stephen Chan Teck Leong

    2012-01-01

    Full Text Available Aspects of the incidence and spread of the citrus disease huanglongbing (HLB in relation to the vector Diaphorina citri population fluctuation were studied from January 1999 to December 2001 seasons in a 0.8 ha citrus orchard at Jemukan (1° 33′N, 110° 41′E, Southwest Sarawak in Malaysia. In relation to insecticide and horticultural mineral oils (HMOs use, levels of HLB infection rose quite rapidly over the next 3 years in the unsprayed control and less rapidly in the other treatments such as imidacloprid, nC24HMO, and triazophos/cypermethrin/chlorpyrifos. Levels of HLB as determined by Polymerase Chain Reaction (PCR were 42.2%, 9.4%, 11.4%, and 22.7%, respectively. The effects of nC24HMO and conventional pesticides on the citrus psyllid population and parasitoids in citrus orchard were also determined.

  10. A revision of the family Ameroseiidae (Acari, Mesostigmata), with some data on Slovak fauna

    Science.gov (United States)

    Mašán, Peter

    2017-01-01

    Abstract The family Ameroseiidae Evans, 1961 (Acari: Mesostigmata) includes a total of 12 valid and adequately described genera, namely Afrocypholaelaps Elsen, 1972, Ameroseiella Bregetova, 1977, Ameroseius Berlese, 1904, Asperolaelaps Womersley, 1956, Brontispalaelaps Womersley, 1956, Epicriopsis Berlese, 1916, Hattena Domrow, 1963, Kleemannia Oudemans, 1930, Neocypholaelaps Vitzthum, 1942, Pseudoameroseius gen. n., Sertitympanum Elsen & Whitaker, 1985 and Sinoseius Bai & Gu, 1995. One of these genera includes subgenera, namely Kleemannia (Primoseius) Womersley, 1956. All genera are reviewed and re-diagnosed, and a dichotomous key is provided for their identification. Ameroseius (50 species), Kleemannia (28 species) and Neocypholaelaps (22 species) are the largest genera in the family. Ameroseiella, Kleemannia, Kleemannia (Primoseius) and Sinoseius are considered to be valid taxa and, in presented systematic classification, they are removed from synonymy with Ameroseius. The genus Pseudoameroseius gen. n., with type species Ameroseius michaelangeli Moraza, 2006 (from Canary Islands), is newly erected to further refine broad primary concept of Ameroseius as understood by some former authors (Karg, Bregetova). Asperolaelaps is removed from synonymy with Neocypholaelaps. Three new species are here described, namely Ameroseius renatae sp. n. (based on specimens from Slovakia), Kleemannia dolichochaeta sp. n. (from Spain) and Kleemannia miranda sp. n. (from U.S.A.). The following new junior synonymies are proposed: Ameroseius apodius Karg, 1971 = Ameroseiella macrochelae (Westerboer, 1963); Ameroseius bregetovae Livshits & Mitrofanov, 1975 = Neocypholaelaps favus Ishikawa, 1968; Ameroseius chinensis Khalili-Moghadam & Saboori, 2016 = Ameroseius guyimingi Ma, 1997; Ameroseius crassisetosus Ye & Ma, 1993, Ameroseius qinghaiensis Li & Yang, 2000 and Ameroseius norvegicus Narita, Abduch & Moraes, 2015 = Ameroseius corbiculus (Sowerby, 1806); Ameroseius dubitatus Berlese

  11. A revision of the family Ameroseiidae (Acari, Mesostigmata, with some data on Slovak fauna

    Directory of Open Access Journals (Sweden)

    Peter Mašán

    2017-09-01

    Full Text Available The family Ameroseiidae Evans, 1961 (Acari: Mesostigmata includes a total of 12 valid and adequately described genera, namely Afrocypholaelaps Elsen, 1972, Ameroseiella Bregetova, 1977, Ameroseius Berlese, 1904, Asperolaelaps Womersley, 1956, Brontispalaelaps Womersley, 1956, Epicriopsis Berlese, 1916, Hattena Domrow, 1963, Kleemannia Oudemans, 1930, Neocypholaelaps Vitzthum, 1942, Pseudoameroseius gen. n., Sertitympanum Elsen & Whitaker, 1985 and Sinoseius Bai & Gu, 1995. One of these genera includes subgenera, namely Kleemannia (Primoseius Womersley, 1956. All genera are reviewed and re-diagnosed, and a dichotomous key is provided for their identification. Ameroseius (50 species, Kleemannia (28 species and Neocypholaelaps (22 species are the largest genera in the family. Ameroseiella, Kleemannia, Kleemannia (Primoseius and Sinoseius are considered to be valid taxa and, in presented systematic classification, they are removed from synonymy with Ameroseius. The genus Pseudoameroseius gen. n., with type species Ameroseius michaelangeli Moraza, 2006 (from Canary Islands, is newly erected to further refine broad primary concept of Ameroseius as understood by some former authors (Karg, Bregetova. Asperolaelaps is removed from synonymy with Neocypholaelaps. Three new species are here described, namely Ameroseius renatae sp. n. (based on specimens from Slovakia, Kleemannia dolichochaeta sp. n. (from Spain and Kleemannia miranda sp. n. (from U.S.A.. The following new junior synonymies are proposed: Ameroseius apodius Karg, 1971 = Ameroseiella macrochelae (Westerboer, 1963; Ameroseius bregetovae Livshits & Mitrofanov, 1975 = Neocypholaelaps favus Ishikawa, 1968; Ameroseius chinensis Khalili-Moghadam & Saboori, 2016 = Ameroseius guyimingi Ma, 1997; Ameroseius crassisetosus Ye & Ma, 1993, Ameroseius qinghaiensis Li & Yang, 2000 and Ameroseius norvegicus Narita, Abduch & Moraes, 2015 = Ameroseius corbiculus (Sowerby, 1806; Ameroseius dubitatus Berlese

  12. Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri, vector of Huanglongbing.

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    Joseph M Patt

    Full Text Available Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las. Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri. Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ, a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected 'Valencia' sweet orange (Citrus sinensis trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid

  13. Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri), vector of Huanglongbing.

    Science.gov (United States)

    Patt, Joseph M; Robbins, Paul S; Niedz, Randy; McCollum, Greg; Alessandro, Rocco

    2018-01-01

    Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las). Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri). Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ), a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected 'Valencia' sweet orange (Citrus sinensis) trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA) and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid colonization during

  14. Infection Density Dynamics of the Citrus Greening Bacterium "Candidatus Liberibacter asiaticus" in Field Populations of the Psyllid Diaphorina citri and Its Relevance to the Efficiency of Pathogen Transmission to Citrus Plants.

    Science.gov (United States)

    Ukuda-Hosokawa, Rie; Sadoyama, Yasutsune; Kishaba, Misaki; Kuriwada, Takashi; Anbutsu, Hisashi; Fukatsu, Takema

    2015-06-01

    Huanglongbing, or citrus greening, is a devastating disease of citrus plants recently spreading worldwide, which is caused by an uncultivable bacterial pathogen, "Candidatus Liberibacter asiaticus," and vectored by a phloem-sucking insect, Diaphorina citri. We investigated the infection density dynamics of "Ca. Liberibacter asiaticus" in field populations of D. citri with experiments using field-collected insects to address how "Ca. Liberibacter asiaticus" infection density in the vector insect is relevant to pathogen transmission to citrus plants. Of 500 insects continuously collected from "Ca. Liberibacter asiaticus"-infected citrus trees with pathological symptoms in the spring and autumn of 2009, 497 (99.4%) were "Ca. Liberibacter asiaticus" positive. The infections were systemic across head-thorax and abdomen, ranging from 10(3) to 10(7) bacteria per insect. In spring, the infection densities were low in March, at ∼ 10(3) bacteria per insect, increasing up to 10(6) to 10(7) bacteria per insect in April and May, and decreasing to 10(5) to 10(6) bacteria per insect in late May, whereas the infection densities were constantly ∼ 10(6) to 10(7) bacteria per insect in autumn. Statistical analysis suggested that several factors, such as insect sex, host trees, and collection dates, may be correlated with "Ca. Liberibacter asiaticus" infection densities in field D. citri populations. Inoculation experiments with citrus seedlings using field-collected "Ca. Liberibacter asiaticus"-infected insects suggested that (i) "Ca. Liberibacter asiaticus"-transmitting insects tend to exhibit higher infection densities than do nontransmitting insects, (ii) a threshold level (∼ 10(6) bacteria per insect) of "Ca. Liberibacter asiaticus" density in D. citri is required for successful transmission to citrus plants, and (iii) D. citri attaining the threshold infection level transmits "Ca. Liberibacter asiaticus" to citrus plants in a stochastic manner. These findings provide

  15. Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri), vector of Huanglongbing

    Science.gov (United States)

    Robbins, Paul S.; Niedz, Randy; McCollum, Greg; Alessandro, Rocco

    2018-01-01

    Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las). Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri). Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ), a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected ‘Valencia’ sweet orange (Citrus sinensis) trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA) and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid colonization during

  16. Padrão morfológico e ciclo de vida de Eutetranychus banksi (Acari: Tetranychidae de diferentes locais e hospedeiros Morphological pattern and life cycle of Eutetranychus banksi (Acari: Tetranychidae from different localities and hosts

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    Viviane M. Mattos

    2009-09-01

    Full Text Available Eutetranychus banksi (McGregor, 1914 is a phytophagous, polyphagous and cosmopolitan species recorded on 23 plant families in 24 countries in North, Central and South Americas, Europe, Asia, and Africa. Specimens of E. banksi present morphological variability among individuals of the same population and also among populations from different host species, being commonly referred to as a polytypic species, despite the fact that studies based on meristic comparisons of these populations are lacking. Also, there is no data available in the literature on the biological life tables of E. banksi on different hosts. Specimens collected in Brazil, Guadeloupe, Martinique, Mexico, and Paraguay were investigated in order to recognize morphological patterns among populations from different localities and hosts. A redescription of the species is provided based on data both from literature and new observations. Also, the biological cycle on three hosts, experiments of hosts exchange and the possibility of interbreeding in individuals originating from different populations were evaluated. Significant differences in the morphology of the females of different populations were detected when comparing the different hosts. The length of the dorsal pairs of setae v2, sc2, c1, c3, e1 and h1 differentiated the specimens of the populations collected from Citrus sp. from those of Hevea brasiliensis Muell. Arg. and Pachira aquatica Aubl.. Herein we observed significant variation among the life cycle of this species on the three hosts studied. When a substrate different from the one where the mites were collected was used for the biological cycle essay, significant variation was observed in several parameters such as average oviposition rate, events of arrenothoky, and sex ratio. Interbreeding with populations collected from Citrus sinensis and P. aquatica resulted in no descendants, although mating was observed.

  17. Transcriptome Analysis of the Carmine Spider Mite, Tetranychus cinnabarinus (Boisduval, 1867 (Acari: Tetranychidae, and Its Response to β-Sitosterol

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    Chunya Bu

    2015-01-01

    Full Text Available Tetranychus cinnabarinus (Acari: Tetranychidae is a worldwide polyphagous agricultural pest that has the title of resistance champion among arthropods. We reported previously the identification of the acaricidal compound β-sitosterol from Mentha piperita and Inula japonica. However, the acaricidal mechanism of β-sitosterol is unclear. Due to the limited genetic research carried out, we de novo assembled the transcriptome of T. cinnabarinus using Illumina sequencing and conducted a differential expression analysis of control and β-sitosterol-treated mites. In total, we obtained >5.4 G high-quality bases for each sample with unprecedented sequencing depth and assembled them into 22,941 unigenes. We identified 617 xenobiotic metabolism-related genes involved in detoxification, binding, and transporting of xenobiotics. A highly expanded xenobiotic metabolic system was found in mites. T. cinnabarinus detoxification genes—including carboxyl/cholinesterase and ABC transporter class C—were upregulated after β-sitosterol treatment. Defense-related proteins, such as Toll-like receptor, legumain, and serine proteases, were also activated. Furthermore, other important genes—such as the chloride channel protein, cytochrome b, carboxypeptidase, peritrophic membrane chitin binding protein, and calphostin—may also play important roles in mites’ response to β-sitosterol. Our results demonstrate that high-throughput-omics tool facilitates identification of xenobiotic metabolism-related genes and illustration of the acaricidal mechanisms of β-sitosterol.

  18. Laboratory evaluation of a native strain of Beauveria bassiana for controlling Dermanyssus gallinae (De Geer, 1778) (Acari: Dermanyssidae).

    Science.gov (United States)

    Immediato, Davide; Camarda, Antonio; Iatta, Roberta; Puttilli, Maria Rita; Ramos, Rafael Antonio Nascimento; Di Paola, Giancarlo; Giangaspero, Annunziata; Otranto, Domenico; Cafarchia, Claudia

    2015-09-15

    The poultry red mite, Dermanyssus gallinae (De Geer, 1778) (Acari: Dermanyssidae) is one of the most economically important ectoparasites of laying hens worldwide. Chemical control of this mite may result in environmental and food contamination, as well as the development of drug resistance. High virulence of Beauveria bassiana sensu lato strains isolated from naturally infected hosts or from their environment has been demonstrated toward many arthropod species, including ticks. However, a limited number of studies have assessed the use of B. bassiana for the control of D. gallinae s.l. and none of them have employed native strains. This study reports the pathogenicity of a native strain of B. bassiana (CD1123) against nymphs and adults of D. gallinae. Batches of nymph and adult mites (i.e., n=720 for each stage) for treated groups (TGs) were placed on paper soaked with a 0.1% tween 80 suspension of B. bassiana (CIS, 10(5), 10(7) and 10(9) conidia/ml), whilst 240 untreated control mites for each stage (CG) were exposed only to 0.1% tween 80. The mites in TG showed a higher mortality at all stages (pbassiana suspension containing 10(9) conidia/ml was highly virulent towards nymph and adult stages of D. gallinae, therefore representing a possible promising natural product to be used in alternative or in combination to other acaricidal compounds currently used for controlling the red mite. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Impact of ectohumus application in birch and pine nurseries on the presence of soil mites (Acari, Oribatida in particular

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    Klimek Andrzej

    2016-03-01

    Full Text Available Intensively used forest nurseries are characterised by degradation processes that lead to a drop in the quality of seedlings. The main reason of this problem is a decrease in biological soil diversity. Therefore, an attempt of nursery soil enrichment by introducing ectohumus – as compost and fresh litter – from the pine forest was carried out. The research was carried out in 2009–2011 in the Bielawy forest nursery near the city of Toruń, Poland. The objective of the study was to determine the impact of organic fertilisation (compost made up of forest humus and mulching using fresh ectohumus on the density and community composition of Acari mites and on species composition of oribatid mites (Oribatida in the nurseries of silver birch and Scots pine. Mites, especially oribatid mites, were treated as bioindicators of soil biological activity. Research has shown that mulching using fresh ectohumus caused a multiple increase in the density of mites, especially in saprophagous mites Oribatida. Oribatid mites were clearly more numerous in birch cultivation than in that of pine. Overall, 27 species of oribatid mites were found. Mulching resulted in a significant growth in species diversity in both cultivations. The most numerous oribatid mite in the area under the study was Oribatula tibialis. This species was present in all plots and showed clear preference for birch cultivation. Tectocepheus velatus and Oppiella nova, common and known to be present in a variety of environments, were slightly less numerous.

  20. Compatibility of reduced-risk insecticides with the non-target predatory mite Iphiseius degenerans (Acari: Phytoseiidae).

    Science.gov (United States)

    Döker, İsmail; Pappas, Maria L; Samaras, Konstantinos; Triantafyllou, Anneta; Kazak, Cengiz; Broufas, George D

    2015-09-01

    Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) is a common predatory mite in citrus orchards in some areas of the Mediterranean basin and an important biological control agent of the thrips Frankliniella occidentalis (Pergande) in Integrated Pest Management (IPM) programmes in greenhouse crops. In this study, we evaluated the effects of the 'reduced-risk' insecticides acetamiprid, chlorantraniliprole, flubendiamide, metaflumizone, methoxyfenozide, spinetoram and thiamethoxam on I. degenerans, as a means of testing their compatibility in IPM programmes. Although all pesticides decreased immature survival, high mortality was only recorded for young larvae when exposed to acetamiprid, while metaflumizone, thiamethoxam and spinetoram resulted in intermediate lethal effects. The estimated LC50 values of acetamiprid, spinetoram and thiamethoxam for I. degenerans females were 0.52, 0.84 and 0.16-fold lower than the respective maximum recommended doses of the pesticides for field application. Although all pesticides tested significantly decreased fecundity, highest rates corresponded to the three pesticides already mentioned. Chlorantraniliprole, flubendiamide and methoxyfenozide may preliminarily be included in IPM programmes, whereas the effects of acetamiprid, metaflumizone, spinetoram and thiamethoxam on I. degenerans should be clarified in further field toxicological tests. This information could be useful for rationally planning and implementing pest management on a sustainable basis. © 2014 Society of Chemical Industry.

  1. Community structure variability of Uropodina mites (Acari: Mesostigmata) in nests of the common mole, Talpa europaea, in Central Europe.

    Science.gov (United States)

    Napierała, Agnieszka; Mądra, Anna; Leszczyńska-Deja, Kornelia; Gwiazdowicz, Dariusz J; Gołdyn, Bartłomiej; Błoszyk, Jerzy

    2016-04-01

    Underground nests of Talpa europaea, known as the common mole, are very specific microhabitats, which are also quite often inhabited by various groups of arthropods. Mites from the suborder Uropodina (Acari: Mesostigmata) are only one of them. One could expect that mole nests that are closely located are inhabited by communities of arthropods with similar species composition and structure. However, results of empirical studies clearly show that even nests which are close to each other can be different both in terms of the species composition and abundance of Uropodina communities. So far, little is known about the factors that can cause these differences. The major aim of this study was to identify factors determining species composition, abundance, and community structure of Uropodina communities in mole nests. The study is based on material collected during a long-term investigation conducted in western parts of Poland. The results indicate that the two most important factors influencing species composition and abundance of Uropodina communities in mole nests are nest-building material and depth at which nests are located. Composition of Uropodina communities in nests of moles was also compared with that of other microhabitats (e.g. rotten wood, forest litter, soil) based on data from 4421 samples collected in Poland. Communities of this habitat prove most similar to these of open areas, especially meadows, as well as some forest types.

  2. The international trade in reptiles (Reptilia)--the cause of the transfer of exotic ticks (Acari: Ixodida) to Poland.

    Science.gov (United States)

    Nowak, Magdalena

    2010-05-11

    The problem of the unnatural transfer of exotic ticks (Acari: Ixodida) on reptiles (Reptilia) imported to Poland is presented. In the period from 2003 to 2007, 382 specimens of reptiles belonging to the following genera were investigated: Testudo, Iguana, Varanus, Gongylophis, Python, Spalerosophis, Psammophis. The reptiles most infested with ticks are imported to Poland from Ghana in Africa, and are the commonly bred terrarium reptiles: Varanus exanthematicus and Python regius. As a result of the investigations, the transfer of exotic ticks on reptiles to Poland was confirmed. There were 2104 specimens of the genera Amblyomma and Hyalomma. The following species were found: Amblyomma exornatum Koch, 1844, Amblyomma flavomaculatum (Lucas, 1846), Amblyomma latum Koch, 1844, Amblyomma nuttalli Donitz, 1909, Amblyomma quadricavum (Schulze, 1941), Amblyomma transversale (Lucas, 1844), Amblyomma varanense (Supino, 1897), Amblyomma sp. Koch, 1844, Hyalomma aegyptium (Linnaeus, 1758). All the species of ticks of genus Amblyomma revealed have been discovered in Poland for the first time. During the research, 13 cases of anomalies of morphological structure were confirmed in the ticks A. flavomaculatum, A. latum and H. aegyptium. The expanding phenomenon of the import of exotic reptiles in Poland and Central Europe is important for parasitological and epidemiological considerations, and therefore requires monitoring and wide-ranging prophylactic activities to prevent the inflow of exotic parasites to Poland. (c) 2010 Elsevier B.V. All rights reserved.

  3. Development and reproductive potential of Tyrophagus putrescentiae (Acari: Acaridae) on plant-parasitic nematodes and artificial diets.

    Science.gov (United States)

    Abou El-Atta, Doaa Abd El-Maksoud; Osman, Mohamed Ali

    2016-04-01

    This study investigated development, reproduction and life table parameters of the astigmatid mold mite Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) feeding on egg-masses or adult females of the nematode Meloidogyne incognita, egg-masses of the nematode Rotylenchulus reniformis, ras cheese or yeast at 25 ± 1 °C, 70 ± 10 % RH in the dark. Immature developmental times were shorter when the mite was fed females of M. incognita followed by yeast. Different prey/diet types had no significant effect on longevity and lifespan of both males and females. Daily oviposition rate (eggs/female/day) was highest for mites fed yeast (20.8 ± 1.8 eggs) and lowest for mites fed females of M. incognita (6.6 ± 0.5). Intrinsic rate of natural increase (r m) was highest for mites fed yeast compared to other prey/diet; no significant differences in r m were observed among mites fed on non-yeast diets. This result may suggest a role of T. putrescentiae as biocontrol agent of plant-parasitic nematodes and the yeast may be used for mite mass-production purposes.

  4. Regional factors rather than forest type drive the community structure of soil living oribatid mites (Acari, Oribatida).

    Science.gov (United States)

    Erdmann, Georgia; Scheu, Stefan; Maraun, Mark

    2012-06-01

    Most European forests are managed by humans. However, the manner and intensity of management vary. While the effect of forest management on above-ground communities has been investigated in detail, effects on the below-ground fauna remain poorly understood. Oribatid mites are abundant microarthropods in forest soil and important decomposers in terrestrial ecosystems. Here, we investigated the effect of four forest types (i.e., managed coniferous forests; 30 and 70 years old managed beech forests; natural beech forests) on the density, diversity and community structure of oribatid mites (Acari). The study was replicated at three regions in Germany: the Swabian Alb, the Hainich and the Schorfheide. To relate changes in oribatid mite community structure to environmental factors, litter mass, pH, C and N content of litter, fine roots and C content of soil were measured. Density of oribatid mites was highest in the coniferous forests and decreased in the order 30 years old, 70 years old, and natural beech forests. Mass of the litter layer and density of oribatid mites were strongly correlated indicating that the litter layer is an important factor regulating oribatid mite densities. Diversity of oribatid mites was little affected by forest type indicating that they harbor similar numbers of niches. Species composition differed between the forest types, suggesting different types of niches. The community structure of oribatid mites differed more strongly between the three regions than between the forest types indicating that regional factors are more important than effects associated with forest type.

  5. Efficacy of plant-derived and synthetic compounds on clothing as repellents against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae).

    Science.gov (United States)

    Jordan, Robert A; Schulze, Terry L; Dolan, Marc C

    2012-01-01

    We conducted field trials to compare the relative repellent activity of two natural product compounds (nootkatone and carvacrol) with commercially available plant-derived (EcoSMART organic insect repellent) and permethrin-based (Repel Permanone) repellents against adult Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae) by using treated coveralls. One day after treatment, nootkatone and carvacrol provided 100% repellency of I. scapularis adults, with nootkatone maintaining complete protection through 3 d, whereas carvacrol showed steadily declining repellency against I. scapularis during the 7-d course of the trials. Nootkatone was at least as effective against host-seeking A. americanum as against I. scapularis through 3 d. Carvacrol provided little protection against A. americanum adults. Both natural compounds performed well initially in comparison with the commercial products. After 7 d, nootkatone was the most effective against both species followed in order of activity by Permanone, EcoSMART, and carvacrol. Nootkatone seems to have offer considerable potential as a clothing repellent against both I. scapularis and A. americanum.

  6. General Electric : Immelt surve all / Jena McGregor

    Index Scriptorium Estoniae

    McGregor, Jena

    2008-01-01

    Ettevõtte General Electric juht Jeffrey R. Immelt võitleb selle nimel, et taastada usaldus firma vastu, kuna laenukriis ja kehvad aktsiahinnad on tekitanud olukorra, kus investorid avaldavad suurt survet ettevõtte juhile. Lisa: GE kindralid

  7. INSECTICIDAS DE BAJO IMPACTO AMBIENTAL PARA EL CONTROL DE Diaphorina citri (HEMIPTERA:PSYLLIDAE EN LIMÓN PERSA EN “LA FORTUNA”, NAYARIT, MÉXICO

    Directory of Open Access Journals (Sweden)

    Isiordia-Aquino N, Ortiz-Catón M

    2013-07-01

    Full Text Available El psílido asiático Diaphorina citri es transmisor de la principal enfermedad de los cítricos (huanglongbing, causada por la bacteria Candidatus Liberibacter spp., en este contexto se realizó el presente estudio con la finalidad de evaluar la eficacia de thiacloprid (0.2 y 0.3 L•ha-1, abamectin (0.6 y 1 L•ha-1, aceite mineral (1 y 2 % y sales de ácidos grasos (0.75 y 1 % en ninfas del psílido, en una huerta de limón persa en “La Fortuna” Tepic, Nayarit, México. Se encontró que solamente el tratamiento de abamectin a dosis de 1 L•ha-1 mostró diferencias a las dos semanas después de la primera aplicación y una semana después de la segunda aplicación, con una media de tres ninfas por brote y 93.1 % de mortalidad en comparación al muestreo inicial. Sin embargo, los tratamientos: aceite mineral (1 y 2 %, sales de ácidos grasos (0.75 y 1 % y abamectin (0.6 L•ha-1 mostraron porcentajes de control de 75 a 90 %, además de que se observó la presencia de enemigos naturales del psílido en los tratamientos de aceite mineral (1 y 2 %, sales de ácidos grasos (0.75 y 1 % y el testigo, lo que pudo haber contribuido a la disminución del 44.4 % en este último tratamiento. Con base en estos resultados, impacto ambiental y el costo de los tratamientos para implementarlos, se concluye que los tratamientos de aceite mineral (1 y 2 % y sales de ácidos grasos (0.75 y 1 % son los que presentaron mayor control de ninfas de D. citri y menor costo de aplicación.

  8. Toxicity of bifenazate and its principal active metabolite, diazene, to Tetranychus urticae and Panonychus citri and their relative toxicity to the predaceous mites, Phytoseiulus persimilis and Neoseiulus californicus.

    Science.gov (United States)

    Ochiai, Noriaki; Mizuno, Masayuki; Mimori, Norihiko; Miyake, Toshihiko; Dekeyser, Mark; Canlas, Liza Jara; Takeda, Makio

    2007-01-01

    Bifenazate is a novel carbazate acaricide discovered by Uniroyal Chemical (now Chemtura Corporation) for the control of phytophagous mites infesting agricultural and ornamental crops. Its acaricidal activity and that of its principal active metabolite, diazene, were characterized. Bifenazate and diazene had high toxicity and specificity both orally and topically to all life stages of Tetranychus urticae and Panonychus citri. Acute poisoning was observed with no temperature dependency. No cross-resistance was found to mites resistant to several other classes of acaricides, such as tebufenpyrad, etoxazole, fenbutatin oxide and dicofol. Bifenazate remained effective for a long time with only about a 10% loss of efficacy on T. urticae after 1 month of application in the field. All stages of development of the predatory mites, Phytoseiulus persimilis and Neoseiulus californicus, survived treatment by both bifenazate and diazene. When adult females of the two predatory mite species were treated with either bifenazate or diazene, they showed a normal level of fecundity and predatory activity in the laboratory, effectively suppressing spider mite population growth. Even when the predators were fed spider mite eggs that had been treated previously with bifenazate, they survived. These findings indicate that bifenazate is a very useful acaricide giving high efficacy, long-lasting activity and excellent selectivity for spider mites. It is, therefore, concluded that bifenazate is an ideal compound for controlling these pest mites.

  9. UFLC-Q-TOF-MS/MS-Based Screening and Identification of Flavonoids and Derived Metabolites in Human Urine after Oral Administration of Exocarpium Citri Grandis Extract

    Directory of Open Access Journals (Sweden)

    Xuan Zeng

    2018-04-01

    Full Text Available Exocarpium Citri grandis (ECG is an important Traditional Chinese Medicine (TCM for the treatment of cough and phlegm, and the flavonoids contained were considered the main effective components. To date, the systematic chemical profiling of these flavonoids and derived in vivo metabolites in human have not been well investigated. ECG was extracted using boiling water and then provided to volunteers for oral administration. Following the ingestion, urine samples were collected from volunteers over 48 h. The extract and urine samples were analyzed using ultra-fast liquid chromatography/quadrupole-time-of-flight tandem mass spectrometry (UFLC-Q-TOF-MS/MS system to screen and identify flavonoids and derived in vivo metabolites. A total of 18 flavonoids were identified in the ECG extract, and 20 metabolites, mainly glucuronide and sulfate conjugates, were screened in urine samples collected post consumption. The overall excretion of naringenin metabolites corresponded to 5.45% of intake and occurred mainly within 4–12 h after the ingestion. Meanwhile, another 29 phenolic catabolites were detected in urine. Obtained data revealed that flavonoids were abundant in the ECG extract, and these components underwent extensive phase II metabolism in humans. These results provided valuable information for further study of the pharmacology and mechanism of action of ECG.

  10. Multi-criteria optimization for ultrasonic-assisted extraction of antioxidants from Pericarpium Citri Reticulatae using response surface methodology, an activity-based approach.

    Science.gov (United States)

    Zeng, Shanshan; Wang, Lu; Zhang, Lei; Qu, Haibin; Gong, Xingchu

    2013-06-01

    An activity-based approach to optimize the ultrasonic-assisted extraction of antioxidants from Pericarpium Citri Reticulatae (Chenpi in Chinese) was developed. Response surface optimization based on a quantitative composition-activity relationship model showed the relationships among product chemical composition, antioxidant activity of extract, and parameters of extraction process. Three parameters of ultrasonic-assisted extraction, including the ethanol/water ratio, Chenpi amount, and alkaline amount, were investigated to give optimum extraction conditions for antioxidants of Chenpi: ethanol/water 70:30 v/v, Chenpi amount of 10 g, and alkaline amount of 28 mg. The experimental antioxidant yield under the optimum conditions was found to be 196.5 mg/g Chenpi, and the antioxidant activity was 2023.8 μmol Trolox equivalents/g of the Chenpi powder. The results agreed well with the second-order polynomial regression model. This presented approach promised great application potentials in both food and pharmaceutical industries. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Characterization of Chemical Composition of Pericarpium Citri Reticulatae Volatile Oil by Comprehensive Two-Dimensional Gas Chromatography with High-Resolution Time-of-Flight Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Kunming Qin

    2013-01-01

    Full Text Available Pericarpium Citri Reticulatae (Chenpi in Chinese has been widely used as an herbal medicine in Korea, China, and Japan. Chenpi extracts are used to treat indigestion and inflammatory syndromes of the respiratory tract such as bronchitis and asthma. This thesis will analyze chemical compositions of Chenpi volatile oil, which was performed by comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry (GC × GC-HR-TOFMS. One hundred and sixty-seven components were tentatively identified, and terpene compounds are the main components of Chenpi volatile oil, a significant larger number than in previous studies. The majority of the eluted compounds, which were identified, were well separated as a result of high-resolution capability of the GC × GC method, which significantly reduces, the coelution. β-Elemene is tentatively qualified by means of GC × GC in tandem with high-resolution TOFMS detection, which plays an important role in enhancing the effects of many anticancer drugs and in reducing the side effects of chemotherapy. This study suggests that GC × GC-HR-TOFMS is suitable for routine characterization of chemical composition of volatile oil in herbal medicines.

  12. Epigenetic regulation of facultative heterochromatinisation in Planococcus citri via the Me(3)K9H3-HP1-Me(3)K20H4 pathway.

    Science.gov (United States)

    Bongiorni, Silvia; Pasqualini, Barbara; Taranta, Monia; Singh, Prim B; Prantera, Giorgio

    2007-03-15

    Using RNA interference (RNAi) we have conducted a functional analysis of the HP1-like chromobox gene pchet2 during embryogenesis of the mealybug Planococcus citri. Knocking down pchet2 expression results in decondensation of the male-specific chromocenter that normally arises from the developmentally-regulated facultative heterochromatinisation of the paternal chromosome complement. Together with the disappearance of the chromocenter the staining levels of two associated histone modifications, tri-methylated lysine 9 of histone H3 [Me(3)K9H3] and tri-methylated lysine 20 of histone H4 [Me(3)K20H4], are reduced to undetectable levels. Embryos treated with double-stranded RNA (dsRNA) targeting pchet2 also exhibit chromosome abnormalities, such as aberrant chromosome condensation, and also the presence of metaphases that contain 'lagging' chromosomes. We conclude that PCHET2 regulates chromosome behavior during metaphase and is a crucial component of a Me(3)K9H3-HP1-Me(3)K20H4 pathway involved in the facultative heterochromatinisation of the (imprinted) paternal chromosome set.

  13. Localization and dynamics of Wolbachia infection in Asian citrus psyllid Diaphorina citri, the insect vector of the causal pathogens of Huanglongbing.

    Science.gov (United States)

    Ren, Su-Li; Li, Yi-Han; Ou, Da; Guo, Yan-Jun; Qureshi, Jawwad A; Stansly, Philip A; Qiu, Bao-Li

    2018-03-23

    Wolbachia is a group of intracellular bacteria that infect a wide range of arthropods including the Asian citrus psyllid (ACP), Diaphorina citri Kuwayama. This insect is the vector of Candidatus Liberibacter asiaticus (CLas), the causal pathogen of Huanglongbing or citrus greening disease. Here, we investigated the localization pattern and infection dynamics of Wolbachia in different developmental stages of ACP. Results revealed that all developmental stages of ACP including egg, 1st-5th instar nymphs, and adults of both gender were infected with Wolbachia. FISH visualization of an ACP egg showed that Wolbachia moved from the egg stalk of newly laid eggs to a randomly distributed pattern throughout the egg prior to hatching. The infection rate varied between nymphal instars. The titers of Wolbachia in fourth and fifth instar nymphs were significantly higher than those in the first and second instar nymphs. Wolbachia were scattered in all nymphal stages, but with highest intensity in the U-shaped bacteriome located in the abdomen of the nymph. Wolbachia was confined to two symmetrical organizations in the abdomen of newly emerged female and male adults. The potential mechanisms of Wolbachia infection dynamics are discussed. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  14. The weathervane model, a functional and structural organization of the two-component alkanesulfonate oxidoreductase SsuD from Xanthomonas citri

    International Nuclear Information System (INIS)

    Pegos, V.R.; Oliveira, P.S.L.; Balan, A.

    2012-01-01

    Full text: In Xanthomonas citri, the phytopathogen responsible for the canker citrus disease, we identified in the ssuABCDE operon, genes encoding the alkanesulfonate ABC transporter as well as the two enzymes responsible for oxido reduction of the respective substrates. SsuD and SsuE proteins represent a two-component system that can be assigned to the group of FMNH 2 -dependent monooxygenases. How- ever, despite of the biochemical information about SsuD and SsuE orthologs from Escherichia coli, there is no structural information of how the two proteins work together. In this work, we used ultracentrifugation, SAXS data and molecular modeling to construct a structural/functional model, which consists of eight molecules organized in a weathervane shape. Through this model, SsuD ligand-binding site for NADPH 2 and FMN substrates is clearly exposed, in a way that might allow the protein-protein interactions with SsuE. Moreover, based on molecular dynamics simulations of SsuD in apo state, docked with NADPH 2 , FMN or both substrates, we characterized the residues of the pocket, the mechanism of substrate interaction and transfer of electrons from NADPH 2 to FMN. This is the first report that links functional and biochemical data with structural analyses. (author)

  15. Experimental infestation with the immatures of Amblyomma dissimile Koch, 1844 (Acari: Ixodidae on Tropidurus torquatus (Lacertilia: Iguanidae and Oryctolagus cuniculus Infestação experimental com as fases imaturas de Amblyomma dissimile Koch, 1844 (Acari: Ixodidae em Tropidurus torquatus (Lacertilia: Iguanidae e Oryctolagus cuniculus

    Directory of Open Access Journals (Sweden)

    L.H.T. Freitas

    2004-02-01

    Full Text Available Larvas provenientes de duas fêmeas de Amblyomma dissimile Koch, 1844 (Acari: Ixodidae, naturalmente ingurgitadas em uma iguana (Iguana iguana e provenientes do Estado do Mato Grosso, foram utilizadas na infestação experimental de lagartos da espécie Tropidurus torquatus e coelhos domésticos. As larvas alimentadas em ambos os hospedeiros realizaram ecdise para ninfas. As ninfas apenas ingurgitaram no lagarto e mudaram para machos e fêmeas. Este é o primeiro registro do parasitismo de larvas e ninfas de A. dissimile em T. torquatus e de larvas em coelhos.

  16. Seletividade de produtos fitossanitários sobre o ácaro predador Agistemus brasiliensis Matioli, Ueckermann & Oliveira (Acari: Stigmaeidae Selectivity ofthe pesticides tothe predaceous mite Agistemus brasiliensis Matioli,, Ueckermann & Oliveira (Acari: Stigmaeidae

    Directory of Open Access Journals (Sweden)

    Marcos Zatti da Silva

    2009-06-01

    Full Text Available Os ácaros predadores das famílias Phytoseiidae e Stigmaeidae constituem-se nos principais inimigos naturais de Brevipalpus phoenicis (Geijskes em citros. Este ácaro-praga causa sérios prejuízos na produção, devido à transmissão do vírus da leprose dos citros (CiLV. Apesar do grande volume de informações sobre a sensibilidade de ácaros Phytoseiidae a agrotóxicos, praticamente não existem informações sobre o efeito desses compostos em ácaros Stigmaeidae no Brasil. Sendo assim, o trabalho teve por objetivo avaliar o efeito dos principais agrotóxicos utilizados em citros sobre o ácaro predador Agistemus brasiliensis Matioli, Ueckermann & Oliveira (Acari: Stigmaeidae, em condições de laboratório. Arenas de folhas de citros da variedade Pera, contendo 25 fêmeas adultas de A. brasiliensis, foram pulverizadas em torre de Potter. Avaliaram-se as mortalidades dos ácaros 72 horas após a aplicação. O efeito dos produtos na reprodução do acarino e a viabilidade dos ovos também foram avaliados. Quanto à seletividade, conforme proposta da "Organização Internacional para o Controle Biológico" (IOBC, os produtos foram classificados como: classe 1 - inócuo (E99%, calda sulfocálcica, cyhexatin, flufenoxuron, hexythiazox, óxido de fenbutatin, propargite, pyridaben e spirodiclofen. Estudos conduzidos em condições de campo ainda são necessários para se compreender melhor o efeito desses agrotóxicos sobre o ácaro predador.The predaceous mites of the families Phytoseiidae and Stigmaeidae are the most important natural enemies of Brevipalpus phoenicis (Geijskes on citrus. This mite causes serious damages to the yield due to the transmission of Citrus leprosis virus (CiLV. Despite the considerable amount of information on susceptibility of phytoseiids to pesticides, the effect of these compounds is not very known for stigmaeid mites in Brazil. This work was carried out to evaluate the effect of the main pesticides used in

  17. Oviposition Behavior and Survival of Tamarixia radiata (Hymenoptera: Eulophidae), an Ectoparasitoid of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae), on Hosts Exposed to an Entomopathogenic Fungus, Isaria fumosorosea (Hypocreales: Cordycipitaceae), Under Laboratory Conditions.

    Science.gov (United States)

    Chow, Andrew; Dunlap, Christopher A; Jackson, Mark A; Flores, Daniel; Patt, Joseph M; Sétamou, Mamoudou

    2016-10-01

    Antagonistic interactions between the nymphal parasitoid, Tamarixia radiata Waterston (Hymenoptera: Eulophidae), and the ARSEF 3581 strain of the entomopathogenic fungus, Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae), could disrupt biological control of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Three interactions were evaluated under laboratory conditions at 25 °C: 1) parasitoid survival if parasitized hosts were exposed to ARSEF 3581 blastospores before or after host mummification; 2) parasitoid survival if mummies containing larva or pupa were exposed to ARSEF 3581 hyphae; 3) parasitoid oviposition on infected hosts with visible or without visible hyphae. Topical application of blastospore formulation onto the dorsal surfaces of live nymphs parasitized with second-instar wasp larva (3 d after parasitism) reduced host mummification by 50% and parasitoid emergence by 85%. However, parasitoid emergence was not affected by topical application of blastospore formulation onto mummies that contained fourth-instar wasp larva (6 d after parasitism). Parasitoid emergence was reduced by 80% if mummies containing fourth-instar wasp larva were covered with blastospore formulation colonized by fungal hyphae. In comparison, parasitoid emergence was not affected if mummies containing wasp pupa (9 d after parasitism) were covered with formulation colonized by fungal hyphae. Female parasitoids oviposited on infected hosts without visible hyphae but not on infected hosts with visible hyphae. Our findings suggest that I. fumosorosea could detrimentally affect T. radiata, if both natural enemies are simultaneously deployed for biological control of D. citri However, temporal separation of the fungus and parasitoid could reduce antagonism and enhance control of D. citri. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. New records of water mites of the family Torrenticolidae (Acari, Hydrachnidia) with descriptions of two new species from Nanshih River system in Taiwan and redescription of Torrenticola ussuriensis (Sokolow, 1940) from the Russian Far East

    Science.gov (United States)

    Pešić, Vladimir; Semenchenko, Ksenia A.; Chatterjee, Tapas; Yam, Rita S.W.; Chan, Benny K.K.

    2011-01-01

    Abstract New records of torrenticolid water mites (Acari: Hydrachnidia, Torrenticolidae) from Nanshih River, Taiwan, are presented. Two new species are described: Torrenticola nanshihensis and Torrenticola taiwanicus; the latter species is compared with Torrenticola ussuriensis (Sokolow, 1940), a poorly known species which is re-described based on a new material from the Russian Far East; Monatractides cf. circuloides (Halík, 1930)is reported for the first time for Taiwan. PMID:21998497

  19. Distribution and Seasonal Activity of Hard Ticks (Acari: Ixododae Infesting Domestic Ruminants in Famenin County, Hamadan Province, Iran

    Directory of Open Access Journals (Sweden)

    F. Fayazkhoo

    2017-10-01

    Full Text Available Background and Objective: Hard ticks (Acari: Ixodidae are one of the most important obligate ectoparasites of vertebrates, belonging to class Arachnida, which transmit a wide range of pathological agents such as viruses, bacteria, and parasites to humans and animals in Iran and around the world. Identifying the distribution of hard ticks in a region is important to monitor their control program, and thereby prevent disease transmission. Materials and Methods: In this cross-sectional descriptive study, sampling was carried out from different parts of the livestock body during four seasons in four geographical directions and five villages of Famenin County, Hamadan Province, Iran, during 2015-2016. The ticks were initially stimulated by using chloroform solution and then separated from domestic ruminants by forceps. The collected ticks were sent to a laboratory, and then their sex and species were identified by using valid diagnostic keys. Results: We studied 800 domestic ruminants, including cattle, sheep, and goats, and found 150 (18.7% cases of infestation. A total of 274 ticks were collected, 259 of which were hard ticks including four genera of Hyalomma, Dermacentor, Repicephlus, and Haemaphysalis. The greatest diversity of species, including Hyalomma scopens (Hy. deteritum, Hyalomma asiaticum, Hyalomma marginatum, and Hyalomma anatolicum belonged to the genus Hyalomma. The frequency rates of Hyalomma, Dermacentor, Rhipicephalus, and Hemaphysalis genera were 73.74%, 15.05%, 10.03%, and 1.15 %, respectively. The highest abundance of ticks was observed in spring (152. Conclusion: The results of this study indicate the diversity of hard ticks in the region and the highest abundance of ticks in spring. Considering the importance of ticks in disease transmission among humans and domestic ruminants, health authorities and respective organizations should take appropriate health measures to control and combat these external parasites.

  20. Removal of drone brood from Apis mellifera (Hymenoptera: Apidae) colonies to control Varroa destructor (Acari: Varroidae) and retain adult drones.

    Science.gov (United States)

    Wantuch, Holly A; Tarpy, David R

    2009-12-01

    The parasitic mite Varroa destructor Anderson & Trueman (Acari: Varroidae) has plagued European honey bees, Apis mellifera L. (Hymenoptera: Apidae), in the Americas since its introduction in the 1980s. For many years, these mites were sufficiently controlled using synthetic acaricides. Recently, however, beekeepers have experienced increased resistance by mites to chemical pesticides, which are also known to leave residues in hive products such as wax and honey. Thus there has been increased emphasis on nonchemical integrated pest management control tactics for Varroa. Because mites preferentially reproduce in drone brood (pupal males), we developed a treatment strategy focusing on salvaging parasitized drones while removing mites from them. We removed drone brood from colonies in which there was no acaricidal application and banked them in separate "drone-brood receiving" colonies treated with pesticides to kill mites emerging with drones. We tested 20 colonies divided into three groups: 1) negative control (no mite treatment), 2) positive control (treatment with acaricides), and 3) drone-brood removal and placement into drone-brood receiving colonies. We found that drone-brood trapping significantly lowered mite numbers during the early months of the season, eliminating the need for additional control measures in the spring. However, mite levels in the drone-brood removal group increased later in the summer, suggesting that this benefit does not persist throughout the entire season. Our results suggest that this method of drone-brood trapping can be used as an element of an integrated control strategy to control varroa mites, eliminating a large portion of the Varroa population with limited chemical treatments while retaining the benefits of maintaining adult drones in the population.

  1. A novel spotted fever group Rickettsia infecting Amblyomma parvitarsum (Acari: Ixodidae) in highlands of Argentina and Chile.

    Science.gov (United States)

    Ogrzewalska, Maria; Nieri-Bastos, Fernanda A; Marcili, Arlei; Nava, Santiago; González-Acuña, Daniel; Muñoz-Leal, Sebastián; Ruiz-Arrondo, Ignacio; Venzal, José M; Mangold, Atilio; Labruna, Marcelo B

    2016-04-01

    The tick Amblyomma parvitarsum (Acari: Ixodidae) has established populations in Andean and Patagonic environments of South America. For the present study, adults of A. parvitarsum were collected in highland areas (elevation >3500 m) of Argentina and Chile during 2009-2013, and tested by PCR for rickettsial infection in the laboratory, and isolation of rickettsiae in Vero cell culture by the shell vial technique. Overall, 51 (62.2%) out of 82 A. parvitarsum adult ticks were infected by spotted fever group (SFG) rickettsiae, which generated DNA sequences 100% identical to each other, and when submitted to BLAST analysis, they were 99.3% identical to corresponding sequence of the ompA gene of Rickettsia sp. strain Atlantic rainforest. Rickettsiae were successfully isolated in Vero cell culture from two ticks, one from Argentina and one from Chile. DNA extracted from the third passage of the isolates of Argentina and Chile were processed by PCR, resulting in partial sequences for three rickettsial genes (gltA, ompB, ompA). These sequences were concatenated and aligned with rickettsial corresponding sequences available in GenBank. Phylogenetic analysis revealed that the A. pavitarsum rickettsial agent grouped under high bootstrap support in a clade composed by the SFG pathogens R. sibirica, R. africae, R. parkeri, Rickettsia sp. strain Atlantic rainforest, and two unnamed SFG agents of unknown pathogenicty, Rickettsia sp. strain NOD, and Rickettsia sp. strain ApPR. The pathogenic role of this A. parvitarsum rickettsia cannot be discarded, since several species of tick-borne rickettsiae that were considered nonpathogenic for decades are now associated with human infections. Copyright © 2016. Published by Elsevier GmbH.

  2. Phylogeny and species delineation in European species of the genus Steganacarus (Acari, Oribatida) using mitochondrial and nuclear markers.

    Science.gov (United States)

    Kreipe, Victoria; Corral-Hernández, Elena; Scheu, Stefan; Schaefer, Ina; Maraun, Mark

    2015-06-01

    Species of the genus Steganacarus are soil-living oribatid mites (Acari, Phthiracaridae) with a ptychoid body. The phylogeny and species status of the species of Steganacarus are not resolved, some authors group all ten German species of Steganacarus within the genus Steganacarus whereas others split them into three subgenera, Steganacarus, Tropacarus and Atropacarus. Additionally, two species, S. magnus and T. carinatus, comprise morphotypes of questionable species status. We investigated the phylogeny and species status of ten European Steganacarus species, i.e. S. applicatus, S. herculeanus, S. magnus forma magna, S. magnus forma anomala, S. spinosus, Tropacarus brevipilus, T. carinatus forma carinata, T. carinatus forma pulcherrima, Atropacarus striculus and Rhacaplacarus ortizi. We used two molecular markers, a 251 bp fragment of the nuclear gene 28S rDNA (D3) and a 477 bp fragment of the mitochondrial COI region. The phylogeny based on a combined analysis of D3 and COI separated four subgenera (Steganacarus, Tropacarus and Atropacarus, Rhacaplacarus) indicating that they form monophyletic groups. The COI region separated all ten species of the genus Steganacarus and showed variation within some species often correlating with the geographic origin of the species. Resolution of the more conserved D3 region was limited, indicating that radiation events are rather recent. Overall, our results indicate that both genes alone cannot be used for phylogeny and barcoding since variation is too low in D3 and too high in COI. However, when used in combination these genes provide reliable insight into the phylogeny, radiation and species status of taxa of the genus Steganacarus.

  3. Mortalidade do ácaro predador Neoseiulus californicus (Acari: Phytoseiidae em testes de toxicidade residual de inseticidas e acaricidas usuais em pomáceas Mortality of predatory mite Neoseiulus californicus (Acari: Phytoseiidae in residual toxicity persistence tests

    Directory of Open Access Journals (Sweden)

    Marcelo Gustavo Ruiz

    2008-12-01

    Full Text Available Os ácaros fitoseídeos, especialmente Neoseiulus californicus (McGregor, são importantes agentes de controle biológico de ácaros tetraniquídeos-praga nas culturas de pomáceas no "Alto Valle del Río Negro y Neuquén", Argentina. Neste trabalho, avaliou-se a mortalidade de N. californicus quando exposto a resíduos dos inseticidas azimphos-methyl, carbaryl e cyfluthrin, e dos acaricidas cyhexatin e propargite. Os produtos foram aplicados às concentrações recomendadas em plantas de pereira. Um, três, seis e dez dias após a aplicação (DAA, folhas tratadas foram retiradas das plantas para a preparação de unidades experimentais. Cinco adultos de N. californicus, provenientes de criação-estoque, foram transferidos para cada unidade, onde pólen de taboa foi fornecido como alimento. As unidades foram mantidas a 25 ± 2 ºC, 60 ± 10% de umidade relativa e fotoperíodo de 14 h. A mortalidade do ácaro foi avaliada 24 h após o confinamento. As médias de mortalidade foram comparadas pelo teste de Dunnett, a 5% de probabilidade. A progressão do declínio do efeito dos produtos testados foi submetida à análise de regressão. Nas duas primeiras datas de avaliação, todos os produtos apresentaram valores de mortalidade significativamente diferentes da testemunha tratada com água. Seis dias após a aplicação, propargite, cyhexatin e cyfluthrin apresentaram mortalidade de aproximadamente 30%, enquanto a mortalidade nos tratamentos azimphos-methyl e carbaryl apresentou níveis estatisticamente similares aos da testemunha. Dez dias após a aplicação, a mortalidade em todos os tratamentos não diferiu significativamente da testemunha. O efeito de todos os produtos apresentou declínio progressivo ao longo do período de observação, sendo significativa a 1% de probabilidade a regressão linear negativa para os valores obtidos. Os maiores efeitos negativos sobre a sobrevivência de N. californicus corresponderam aos acaricidas testados

  4. Behavioral, Ultrastructural and Chemical Studies on the Honeydew and Waxy Secretions by Nymphs and Adults of the Asian Citrus Psyllid Diaphorina citri (Hemiptera: Psyllidae)

    Science.gov (United States)

    Ammar, El-Desouky; Alessandro, Rocco; Shatters Jr, Robert G.; Hall, David G.

    2013-01-01

    The Asian citrus psyllid (ACP), Diaphorina citri (Hemiptera: Psyllidae) is the primary vector of the bacterium causing citrus huanglongbing (citrus greening), the most serious disease of citrus worldwide. Psyllids and other hemipterans produce large amounts of honeydew, which has been used previously as an indicator of phloem sap composition and insect feeding or metabolism. Behavioral, ultrastructural and chemical studies on ACP, its honeydew and waxy secretions showed important differences between nymphs, males and females, and suggested some mechanisms by which the psyllids, especially nymphs and adult females, can minimize their contamination with honeydew excretions. The anal opening in ACP, near the posterior end of the abdomen, is on the ventral side in nymphs and on the dorsal side in adult males and females. Video recordings showed that adult males produce clear sticky droplets of honeydew gently deposited behind their body on the leaf surface, whereas adult females produce whitish honeydew pellets powerfully propelled away from the female body, probably to get their excretions away from eggs and newly hatched nymphs. ACP nymphs produce long ribbons or tubes of honeydew that frequently stay attached to the exuviae after molting, or drop when feeding on the lower side of citrus leaves. Furthermore, honeydew excretions of both nymphs and adult females are covered with a thin layer of whitish waxy material ultrastructurally composed of a convoluted network of long fine filaments or ribbons. This material is extruded from intricate arrays of wax pores in the circumanal ring (around the anus) that is found in nymphs and females but not in males of ACP or other psyllid species. Infrared microscopy and mass spectroscopy revealed that, in addition to various sugars, honeydew excretions of ACP nymphs and females are covered with a thin layer of wax similar in profile to ester waxes. PMID:23762268

  5. Simultaneous Quantification of Seven Bioactive Flavonoids in Citri Reticulatae Pericarpium by Ultra-Fast Liquid Chromatography Coupled with Tandem Mass Spectrometry.

    Science.gov (United States)

    Zhao, Lian-Hua; Zhao, Hong-Zheng; Zhao, Xue; Kong, Wei-Jun; Hu, Yi-Chen; Yang, Shi-Hai; Yang, Mei-Hua

    2016-05-01

    Citri Reticulatae Pericarpium (CRP) is a commonly-used traditional Chinese medicine with flavonoids as the major bioactive components. Nevertheless, the contents of the flavonoids in CRP of different sources may significantly vary affecting their therapeutic effects. Thus, the setting up of a reliable and comprehensive quality assessment method for flavonoids in CRP is necessary. To set up a rapid and sensitive ultra-fast liquid chromatography coupled with tandem mass spectrometry (UFLC-MS/MS) method for simultaneous quantification of seven bioactive flavonoids in CRP. A UFLC-MS/MS method coupled to ultrasound-assisted extraction was developed for simultaneous separation and quantification of seven flavonoids including hesperidin, neohesperidin, naringin, narirutin, tangeretin, nobiletin and sinensetin in 16 batches of CRP samples from different sources in China. The established method showed good linearity for all analytes with correlation coefficient (R) over 0.9980, together with satisfactory accuracy, precision and reproducibility. Furthermore, the recoveries at the three spiked levels were higher than 89.71% with relative standard deviations (RSDs) lower than 5.19%. The results indicated that the contents of seven bioactive flavonoids in CRP varied significantly among different sources. Among the samples under study, hesperidin showed the highest contents in 16 samples ranged from 27.50 to 86.30 mg/g, the contents of hesperidin in CRP-15 and CRP-9 were 27.50 and 86.30 mg/g, respectively, while, the amount of narirutin was too low to be measured in some samples. This study revealed that the developed UFLC-MS/MS method was simple, sensitive and reliable for simultaneous quantification of multi-components in CRP with potential perspective for quality control of complex matrices. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  6. A plant natriuretic peptide-like molecule of the pathogen Xanthomonas axonopodis pv. citri causes rapid changes in the proteome of its citrus host

    KAUST Repository

    Garavaglia, Betiana S; Thomas, Ludivine; Zimaro, Tamara; Gottig, Natalia; Daurelio, Lucas D; Ndimba, Bongani; Orellano, Elena G; Ottado, Jorgelina; Gehring, Christoph A

    2010-01-01

    Background: Plant natriuretic peptides (PNPs) belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. The citrus pathogen Xanthomonas axonopodis pv. citri possesses a PNP-like peptide (XacPNP) uniquely present in this bacteria. Previously we observed that the expression of XacPNP is induced upon infection and that lesions produced in leaves infected with a XacPNP deletion mutant were more necrotic and lead to earlier bacterial cell death, suggesting that the plant-like bacterial PNP enables the plant pathogen to modify host responses in order to create conditions favorable to its own survival.Results: Here we measured chlorophyll fluorescence parameters and water potential of citrus leaves infiltrated with recombinant purified XacPNP and demonstrate that the peptide improves the physiological conditions of the tissue. Importantly, the proteomic analysis revealed that these responses are mirrored by rapid changes in the host proteome that include the up-regulation of Rubisco activase, ATP synthase CF1 ? subunit, maturase K, and ?- and ?-tubulin.Conclusions: We demonstrate that XacPNP induces changes in host photosynthesis at the level of protein expression and in photosynthetic efficiency in particular. Our findings suggest that the biotrophic pathogen can use the plant-like hormone to modulate the host cellular environment and in particular host metabolism and that such modulations weaken host defence. 2010 Garavaglia et al; licensee BioMed Central Ltd.

  7. A plant natriuretic peptide-like molecule of the pathogen Xanthomonas axonopodis pv. citri causes rapid changes in the proteome of its citrus host

    Directory of Open Access Journals (Sweden)

    Ottado Jorgelina

    2010-03-01

    Full Text Available Abstract Background Plant natriuretic peptides (PNPs belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. The citrus pathogen Xanthomonas axonopodis pv. citri possesses a PNP-like peptide (XacPNP uniquely present in this bacteria. Previously we observed that the expression of XacPNP is induced upon infection and that lesions produced in leaves infected with a XacPNP deletion mutant were more necrotic and lead to earlier bacterial cell death, suggesting that the plant-like bacterial PNP enables the plant pathogen to modify host responses in order to create conditions favorable to its own survival. Results Here we measured chlorophyll fluorescence parameters and water potential of citrus leaves infiltrated with recombinant purified XacPNP and demonstrate that the peptide improves the physiological conditions of the tissue. Importantly, the proteomic analysis revealed that these responses are mirrored by rapid changes in the host proteome that include the up-regulation of Rubisco activase, ATP synthase CF1 α subunit, maturase K, and α- and β-tubulin. Conclusions We demonstrate that XacPNP induces changes in host photosynthesis at the level of protein expression and in photosynthetic efficiency in particular. Our findings suggest that the biotrophic pathogen can use the plant-like hormone to modulate the host cellular environment and in particular host metabolism and that such modulations weaken host defence.

  8. Effect of whole yeast cell product supplementation (CitriStim®) on immune responses and cecal microflora species in pullet and layer chickens during an experimental coccidial challenge.

    Science.gov (United States)

    Markazi, Ashley D; Perez, Victor; Sifri, Mamduh; Shanmugasundaram, Revathi; Selvaraj, Ramesh K

    2017-07-01

    Three separate experiments were conducted to study the effects of whole yeast cell product supplementation in pullets and layer hens. Body weight gain, fecal and intestinal coccidial oocyst counts, cecal microflora species, cytokine mRNA amounts, and CD4+ and CD8+ T-cell populations in the cecal tonsils were analyzed following an experimental coccidial infection. In Experiment I, day-old Leghorn layer chicks were fed 3 experimental diets with 0, 0.1, or 0.2% whole yeast cell product (CitriStim®, ADM, Decatur, IL). At 21 d of age, birds were challenged with 1 × 105 live coccidial oocysts. Supplementation with whole yeast cell product decreased the fecal coccidial oocyst count at 7 (P = 0.05) and 8 (P product and challenged with 1 × 105 live coccidial oocysts on d 25 of whole yeast cell product feeding. Supplementation with whole yeast cell product decreased the coccidial oocyst count in the intestinal content (P product increased relative proportion of Lactobacillus (P product decreased CD8+ T cell percentages (P product and challenged with 1 × 105 live coccidial oocysts on d 66 of whole yeast cell product feeding. At 5 d post-coccidial challenge, whole yeast cell product supplementation down-regulated (P = 0.01) IL-10 mRNA amount. It could be concluded that supplementing whole yeast cell product can help minimize coccidial infection in both growing pullets and layer chickens. © 2017 Poultry Science Association Inc.

  9. A plant natriuretic peptide-like molecule of the pathogen Xanthomonas axonopodis pv. citri causes rapid changes in the proteome of its citrus host

    KAUST Repository

    Garavaglia, Betiana S

    2010-03-21

    Background: Plant natriuretic peptides (PNPs) belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. The citrus pathogen Xanthomonas axonopodis pv. citri possesses a PNP-like peptide (XacPNP) uniquely present in this bacteria. Previously we observed that the expression of XacPNP is induced upon infection and that lesions produced in leaves infected with a XacPNP deletion mutant were more necrotic and lead to earlier bacterial cell death, suggesting that the plant-like bacterial PNP enables the plant pathogen to modify host responses in order to create conditions favorable to its own survival.Results: Here we measured chlorophyll fluorescence parameters and water potential of citrus leaves infiltrated with recombinant purified XacPNP and demonstrate that the peptide improves the physiological conditions of the tissue. Importantly, the proteomic analysis revealed that these responses are mirrored by rapid changes in the host proteome that include the up-regulation of Rubisco activase, ATP synthase CF1 ? subunit, maturase K, and ?- and ?-tubulin.Conclusions: We demonstrate that XacPNP induces changes in host photosynthesis at the level of protein expression and in photosynthetic efficiency in particular. Our findings suggest that the biotrophic pathogen can use the plant-like hormone to modulate the host cellular environment and in particular host metabolism and that such modulations weaken host defence. 2010 Garavaglia et al; licensee BioMed Central Ltd.

  10. Stylet morphometrics and citrus leaf vein structure in relation to feeding behavior of the Asian citrus psyllid Diaphorina citri, vector of citrus huanglongbing bacterium.

    Directory of Open Access Journals (Sweden)

    El-Desouky Ammar

    Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri (Hemiptera: Psyllidae, is the primary vector of the phloem-limited bacterium Candidatus Liberibacter asiaticus (LAS associated with huanglongbing (HLB, citrus greening, considered the world's most serious disease of citrus. Stylet morphometrics of ACP nymphs and adults were studied in relation to citrus vein structure and to their putative (histologically verified feeding sites on Valencia orange leaves. ACP nymphs preferred to settle and feed on the lower (abaxial side of young leaves either on secondary veins or on the sides of the midrib, whereas adults preferred to settle and feed on the upper (adaxial or lower secondary veins of young or old leaves. Early instar nymphs can reach and probe the phloem probably because the distance to the phloem is considerably shorter in younger than in mature leaves, and is shorter from the sides of the midrib compared to that from the center. Additionally, the thick-walled 'fibrous ring' (sclerenchyma around the phloem, which may act as a barrier to ACP stylet penetration into the phloem, is more prominent in older than in younger leaves and in the center than on the sides of the midrib. The majority (80-90% of the salivary sheath termini produced by ACP nymphs and adults that reached a vascular bundle were associated with the phloem, whereas only 10-20% were associated with xylem vessels. Ultrastructural studies on ACP stylets and LAS-infected leaves suggested that the width of the maxillary food canal in first instar nymphs is wide enough for LAS bacteria to traverse during food ingestion (and LAS acquisition. However, the width of the maxillary salivary canal in these nymphs may not be wide enough to accommodate LAS bacteria during salivation (and LAS inoculation into host plants. This may explain the inability of early instar nymphs to transmit LAS/HLB in earlier reports.

  11. Behavioral, ultrastructural and chemical studies on the honeydew and waxy secretions by nymphs and adults of the Asian citrus psyllid Diaphorina citri (Hemiptera: Psyllidae.

    Directory of Open Access Journals (Sweden)

    El-Desouky Ammar

    Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri (Hemiptera: Psyllidae is the primary vector of the bacterium causing citrus huanglongbing (citrus greening, the most serious disease of citrus worldwide. Psyllids and other hemipterans produce large amounts of honeydew, which has been used previously as an indicator of phloem sap composition and insect feeding or metabolism. Behavioral, ultrastructural and chemical studies on ACP, its honeydew and waxy secretions showed important differences between nymphs, males and females, and suggested some mechanisms by which the psyllids, especially nymphs and adult females, can minimize their contamination with honeydew excretions. The anal opening in ACP, near the posterior end of the abdomen, is on the ventral side in nymphs and on the dorsal side in adult males and females. Video recordings showed that adult males produce clear sticky droplets of honeydew gently deposited behind their body on the leaf surface, whereas adult females produce whitish honeydew pellets powerfully propelled away from the female body, probably to get their excretions away from eggs and newly hatched nymphs. ACP nymphs produce long ribbons or tubes of honeydew that frequently stay attached to the exuviae after molting, or drop when feeding on the lower side of citrus leaves. Furthermore, honeydew excretions of both nymphs and adult females are covered with a thin layer of whitish waxy material ultrastructurally composed of a convoluted network of long fine filaments or ribbons. This material is extruded from intricate arrays of wax pores in the circumanal ring (around the anus that is found in nymphs and females but not in males of ACP or other psyllid species. Infrared microscopy and mass spectroscopy revealed that, in addition to various sugars, honeydew excretions of ACP nymphs and females are covered with a thin layer of wax similar in profile to ester waxes.

  12. Detection of Babesia spp. in Dogs and Their Ticks From Peninsular Malaysia: Emphasis on Babesia gibsoni and Babesia vogeli Infections in Rhipicephalus sanguineus sensu lato (Acari: Ixodidae).

    Science.gov (United States)

    Prakash, Batah Kunalan; Low, Van Lun; Vinnie-Siow, Wei Yin; Tan, Tiong Kai; Lim, Yvonne Ai-Lian; Morvarid, Akhavan Rezaei; AbuBakar, Sazaly; Sofian-Azirun, Mohd

    2018-05-12

    Canine babesiosis is an emerging tick-borne disease with a worldwide distribution, including Malaysia. While the prevalence of Babesia has been documented from dogs in Malaysia, occurrence of Babesia has been relatively little studied in their tick vectors. Accordingly, a total of 240 dogs and 140 Rhipicephalus sanguineus sensu lato (s.l.) (Acari: Ixodidae) ticks from Malaysia were molecularly screened for the presence of Babesia protozoa in the present study. Babesia gibsoni was only detected in ticks (1.4%), whereas Babesia vogeli was detected in both ticks (1.4%) and dogs (2.1%). This study highlights the detection of B. gibsoni and B. vogeli for the first time, in both adult and nymphal stages of R. sanguineus s.l. in Malaysia, suggesting the potential role of this tick species in transmitting canine babesiosis.

  13. Expression analysis of Drosophila doublesex, transformer-2, intersex, fruitless-like, and vitellogenin homologs in the parahaploid predator Metaseiulus occidentalis (Chelicerata: Acari: Phytoseiidae).

    Science.gov (United States)

    Pomerantz, Aaron F; Hoy, Marjorie A

    2015-01-01

    Characterization and expression analyses are essential to gain insight into sex-determination pathways in members of the Acari. Little is known about sex determination at the molecular level in the western orchard predatory mite Metaseiulus occidentalis (Arthropoda: Chelicerata: Arachnida: Acari: Phytoseiidae), a parahaploid species. In this study, eight genes previously identified as putative homologs to genes involved in the sex-determination pathway in Drosophila melanogaster were evaluated for sex-specific alternative splicing and sex-biased expression using reverse-transcriptase PCR and quantitative real-time PCR techniques, respectively. The homologs evaluated in M. occidentalis included two doublesex-like genes (Moccdsx1 and Moccdsx2), transformer-2 (Mocctra-2), intersex (Moccix), two fruitless-like genes (MoccBTB1 and MoccBTB2), as well as two vitellogenin-like genes (Moccvg1 and Moccvg2). Single transcripts of equal size were detected in males and females for Moccdsx1, Moccdsx2, Mocctra-2, Moccix, and MoccBTB2, suggesting that their pre-mRNAs do not undergo alternative splicing in a sex-specific manner. Three genes, Moccdsx1, Moccdsx2 and MoccBTB2, displayed male-biased expression relative to females. One gene, Moccix, displayed female-biased expression relative to males. Two genes, Mocctra-2 and MoccBTB1, did not display detectable differences in transcript abundance in males and females. Expression of Moccvg1 and Moccvg2 were detected in females only, and transcript levels were up-regulated in mated females relative to unmated females. To our knowledge, this represents the first attempt to elucidate expression patterns of putative sex-determination genes in an acarine. This study is an initial step towards understanding the sex-determination pathway in the parahaploid M. occidentalis.

  14. Crystallization and preliminary X-ray diffraction analysis of XAC1151, a small heat-shock protein from Xanthomonas axonopodis pv. citri belonging to the α-crystallin family

    Energy Technology Data Exchange (ETDEWEB)

    Hilario, Eduardo; Teixeira, Elaine Cristina; Pedroso, Gisele Audrei; Bertolini, Maria Célia [Departamento de Bioquímica e Tecnologia Química, Instituto de Química, Universidade Estadual Paulista, Araraquara-SP (Brazil); Medrano, Francisco Javier, E-mail: fjmedrano@yahoo.com [Departamento de Cristalografia de Proteínas, Centro de Biologia Molecular Estrutural, Laboratório Nacional de Luz Síncrotron, Caixa Postal 6192, CEP 13084-971, Campinas-SP (Brazil); Departamento de Bioquímica e Tecnologia Química, Instituto de Química, Universidade Estadual Paulista, Araraquara-SP (Brazil)

    2006-05-01

    XAC1151, a small heat-shock protein from X. axonopodis pv. citri belonging to the α-crystallin family, was crystallized using the sitting-drop vapour-diffusion method in the presence of ammonium phosphate. X-ray diffraction data were collected to 1.65 Å resolution using a synchrotron-radiation source. The hspA gene (XAC1151) from Xanthomonas axonopodis pv. citri encodes a protein of 158 amino acids that belongs to the small heat-shock protein (sHSP) family of proteins. These proteins function as molecular chaperones by preventing protein aggregation. The protein was crystallized using the sitting-drop vapour-diffusion method in the presence of ammonium phosphate. X-ray diffraction data were collected to 1.65 Å resolution using a synchrotron-radiation source. The crystal belongs to the rhombohedral space group R3, with unit-cell parameters a = b = 128.7, c = 55.3 Å. The crystal structure was solved by molecular-replacement methods. Structure refinement is in progress.

  15. Novel bacterial pathogen Acaricomes phytoseiuli causes severe disease symptoms and histopathological changes in the predatory mite Phytoseiulus persimilis (Acari, Phytoseiidae).

    Science.gov (United States)

    Schütte, Conny; Gols, Rieta; Kleespies, Regina G; Poitevin, Olivier; Dicke, Marcel

    2008-06-01

    Adult female Phytoseiulus persimilis Athias-Henriot (Acari, Phytoseiidae) of a laboratory population show a set of characteristic symptoms, designated as non-responding (NR) syndrome. Mature predators shrink, cease oviposition and die. They show a lower degree of attraction to herbivore-induced plant volatiles and a greater tendency to leave prey patches carrying ample prey. Moreover, predators may carry excretory crystals in the legs, may cease prey consumption and have a low excretion rate. Here, we satisfy Koch's postulates for a strain of Acaricomes phytoseiuli (DSM 14247) that was isolated from symptomatic female P. persimilis of the NR-population. Adult female P. persimilis were either exposed to a bacterial inoculum suspension (treatment) or to sterile distilled water (control) for a period of 3 days. Control and treated predators were examined for the occurrence of six symptoms characteristic for the NR-syndrome and the presence of A. phytoseiuli after inoculation. The latter was done by re-isolation of A. phytoseiuli from individual predators and predator feces placed on nutrient agar, by PCR-based identification and by histopathological studies of individual predators. The NR-syndrome was clearly induced in those predators that had been exposed to the bacterial inoculum (incubation time=2-5 days, fraction shrunken females=80%), whereas predators exposed to water did not show the NR-syndrome. A. phytoseiuli was never isolated from control predators whereas it could be re-isolated from 60% of the treated predators (N=37) and from feces of 41% of treated predators (N=17). Only one day after exposure A. phytoseiuli could not be re-isolated from treated predators and their feces. Light and electron microscope studies of predators exposed to A. phytoseiuli revealed striking bacterial accumulations in the lumen of the alimentary tract together with extreme degeneration of its epithelium. In addition, bacterial foci also occurred in the fat body. These phenomena

  16. A novel disease affecting the predatory mite Phytoseiulus persimilis (Acari, Phytoseiidae): 2. Disease transmission by adult females.

    Science.gov (United States)

    Schütte, Conny; Poitevin, Olivier; Negash, Tesfaye; Dicke, Marcel

    2006-01-01

    Adult female Phytoseiulus persimilis Athias-Henriot (Acari, Phytoseiidae) of one of our laboratory populations (=NR-population), show the following set of symptoms: predators shrink several days after mating, cease egg production and die several days after shrinking, show a lower degree of attraction to herbivore-induced plant volatiles and a shorter choice time in olfactometer tests, have the tendency to leave a prey patch with ample food, may carry excretory crystals in the legs, may cease prey consumption, and have a lower excretion rate. We hypothesized earlier that this characteristic syndrome, called non-responding (=NR-) syndrome, is caused by a pathogen infecting P. persimilis. To further support this hypothesis we here study several transmission modes of the factor causing the NR-syndrome. In all tests we measured size, short-term fecundity, mortality, predator position, response to plant odors and crystal location, thus including 6 of the 9 symptoms known yet. No evidence was found for vertical transmission from parent to offspring. Eggs from symptomatic females of the NR-population mated by males of the NR-population gave rise to normal-sized, well performing predators, when they had been surface sterilized or transferred to a new leaf. However, such eggs gave rise to shrunken females (17%) when left on the leaf where they had been laid. In the latter case transmission via products deposited on the leaf by the mothers was possible. We therefore tested several modes of horizontal transmission by exposing females of a commercial population that never showed the NR-syndrome (=R1-population) to products related to the symptomatic NR-population. No evidence was found for transmission via food or via squashed adult females. However, symptoms were induced in adult females of the R1-population after a 3-day exposure to a live adult female of the NR-population (incubation period=3-7 days, fraction shrunken females=53%) and after a 1-day exposure to feces and

  17. A TALE of transposition: Tn3-like transposons play a major role in the spread of pathogenicity determinants of Xanthomonas citri and other xanthomonads.

    Science.gov (United States)

    Ferreira, Rafael Marini; de Oliveira, Amanda Carolina P; Moreira, Leandro M; Belasque, José; Gourbeyre, Edith; Siguier, Patricia; Ferro, Maria Inês T; Ferro, Jesus A; Chandler, Michael; Varani, Alessandro M

    2015-02-17

    Members of the genus Xanthomonas are among the most important phytopathogens. A key feature of Xanthomonas pathogenesis is the translocation of type III secretion system (T3SS) effector proteins (T3SEs) into the plant target cells via a T3SS. Several T3SEs and a murein lytic transglycosylase gene (mlt, required for citrus canker symptoms) are found associated with three transposition-related genes in Xanthomonas citri plasmid pXAC64. These are flanked by short inverted repeats (IRs). The region was identified as a transposon, TnXax1, with typical Tn3 family features, including a transposase and two recombination genes. Two 14-bp palindromic sequences within a 193-bp potential resolution site occur between the recombination genes. Additional derivatives carrying different T3SEs and other passenger genes occur in different Xanthomonas species. The T3SEs include transcription activator-like effectors (TALEs). Certain TALEs are flanked by the same IRs as found in TnXax1 to form mobile insertion cassettes (MICs), suggesting that they may be transmitted horizontally. A significant number of MICs carrying other passenger genes (including a number of TALE genes) were also identified, flanked by the same TnXax1 IRs and delimited by 5-bp target site duplications. We conclude that a large fraction of T3SEs, including individual TALEs and potential pathogenicity determinants, have spread by transposition and that TnXax1, which exhibits all of the essential characteristics of a functional transposon, may be involved in driving MIC transposition. We also propose that TALE genes may diversify by fork slippage during the replicative Tn3 family transposition. These mechanisms may play a crucial role in the emergence of Xanthomonas pathogenicity. Xanthomonas genomes carry many insertion sequences (IS) and transposons, which play an important role in their evolution and architecture. This study reveals a key relationship between transposons and pathogenicity determinants in

  18. Ocorrência de Ornithonyssus bursa (Berlese, 1888 (Acari: Macronyssidae em filhotes de Megascops choliba (corujinha-do-mato e Pitangus sulphuratus (bem-te-vi, no Rio Grande do Sul, Brasil Ocurrence of Ornithonyssus bursa (Berlese, 1888 (Acari: Macronyssidae on Megascops choliba (tropical screech-owl and Pitangus sulphuratus (great kiskadee nestlings in the Rio Grande do Sul State, Brazil

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    Carolina S. Mascarenhas

    2009-12-01

    Full Text Available O Núcleo de Reabilitação da Fauna Silvestre e Centro de Triagem de Animais Silvestres da Universidade Federal de Pelotas - RS atendeu dois filhotes de Megascops choliba (corujinha-do-mato (Strigiformes - Strigidae e dois de Pitangus sulphuratus (bem-te-vi (Passeriformes - Tyrannidae intensamente parasitados por ácaros, em maio de 2005 e dezembro de 2006, respectivamente. Os filhotes e o ninho de P. sulphuratus foram recolhidos na zona urbana da cidade de Pelotas - RS após forte temporal. Os ácaros foram removidos, colocados em álcool 70% e levados ao laboratório de parasitologia para identificação. Os espécimes foram clarificados em lactofenol, montados em meio de Hoyer e identificados como Ornithonyssus bursa (Acari - Macronyssidae. Registra-se Megascops choliba e Pitangus sulphuratus como hospedeiros de Ornithonyssus bursa, no Rio Grande do Sul, Brasil.The Center for Rehabilitation of Wildlife and Center for Selection of Wild Animal of the Federal University of Pelotas has attended two nestlings of Megascops choliba (tropical screech-owl (Strigiformes - Strigidae and two of Pitangus sulphuratus (great kiskadee (Passeriformes - Tyrannidae heavily parasitized by mites, in May 2005 and December 2006, respectively. The nestlings and the nest of P. sulphuratus were collected in the Pelotas urban area after severe storms. The mites were removed, clarified in lactofenol, permanently mounted in Hoyer's medium and identified as Ornithonyssus bursa (Acari - Macronyssidae. Megascops choliba and Pitangus sulphuratus are reported as host of Ornithonyssus bursa in Rio Grande do Sul State, Brazil.

  19. Amostragem, caracterização de sintomas e escala diagramática da mancha graxa dos citros (Mycosphaerella citri no Recôncavo Baiano Sampling, characterization of citrus greasy spot (Mycosphaerella citri symptoms in Recôncavo Baiano and development of a diagrammatic scale for assessment of severity

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    Suely Xavier de Brito Silva

    2009-06-01

    Full Text Available O Recôncavo da Bahia é uma região de clima propício à mancha graxa dos citros (Mycosphaerella citri, doença nunca antes estudada no Brasil. Os objetivos deste trabalho foram definir o tamanho mínimo de amostra para quantificar a incidência, caracterizar os sintomas da doença e elaborar uma escala diagramática para a avaliação de sua severidade. A partir de uma amostragem piloto realizada por avaliação de cinco folhas por quadrante, quatro quadrantes por planta e 30 plantas em cada um dos 10 pomares visitados no município de Cruz das Almas, foi determinado que o tamanho mínimo da amostra em quadrantes e folhas seria de quatro e 16 plantas, respectivamente. De 320 folhas coletadas de diferentes plantas em 11 pomares, foi constatada uma grande quantidade de lesões (média de 131 por folha sintomática, em sua maioria diminutas (média de 0,014cm². A severidade variou de 0,15% a 35,85%, com média de 7,3%. Com base na severidade real em campo, foi elaborada uma escala diagramática com seis níveis: 1%, 2%, 5%, 9%, 18% e 36% de área foliar lesionada. Cinqüenta imagens de folhas foram submetidas a avaliadores por duas vezes, os quais estimaram a severidade com e sem a utilização da escala, constatando-se um discreto benefício no grau de precisão e de acurácia das estimativas com o uso da escala.Weather conditions make the Recôncavo Region in the State of Bahia, a favorable region to the occurrence of citrus greasy spot (Mycosphaerella citri, a disease that hadn't been studied before in Brazil. Thus, this research aimed to develop a sampling method to quantify its incidence, to characterize its symptoms, and to develop a diagrammatic scale for assessing disease severity. The minimum sample size to estimate greasy spot incidence in leaves (16 plants was calculated based on a prospective sampling of five leaves per quadrant, four quadrants per tree, and 30 trees per grove, in ten groves. From 320 mature leaves collected in

  20. Aspectos biológicos da fase adulta de Chrysoperla externa (Hagen, 1861 (Neuroptera: Chrysopidae oriunda de larvas alimentadas com Planococcus citri (Risso, 1813 (Hemiptera: Pseudococcidae Biological aspects of the adult stage of Chrysoperla externa (Hagen, 1861 (Neuroptera: Chrysopidae originating from the larvae fed Planococcus citri (Risso, 1813 (Hemiptera: Pseudococcidae

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    Gerane Celly Dias Bezerra

    2006-08-01

    Full Text Available Objetivou-se estudar alguns aspectos biológicos da fase adulta de Chrysoperla externa (Hagen quando as larvas desse predador foram alimentadas com ninfas e fêmeas adultas de Planococcus citri (Risso. O experimento foi conduzido em câmara climatizada regulada a 25 ± 1 ºC, 70 ± 10% de UR e fotofase de 12 horas. Os adultos de C. externa cujas larvas foram alimentadas com ninfas nos três ínstares e fêmeas adultas da cochonilha, foram separados por sexo e 25 casais foram individualizados em gaiolas determinando-se a razão sexual, período de pré-oviposição, capacidade de oviposição diária e total durante 40 dias consecutivos, longevidade, período embrionário e viabilidade de ovos. Constatou-se que as ninfas nos três ínstares e fêmeas adultas fornecidas como alimento, não afetaram a razão sexual, período de pré-oviposição, período embrionário e longevidade dos adultos de C. externa. A produção diária e total de ovos por C. externa foi afetada pelo tipo de alimento fornecido ao predador durante a fase de larva, observando-se uma maior produção quando os casais foram alimentados na fase de larva com fêmeas adultas da cochonilha. Analisando-se a produção de ovos, observou-se uma maior concentração de oviposição nos primeiros dez dias do período reprodutivo, decrescendo nas avaliações seguintes. Foram obtidas porcentagens maiores de ovos viáveis e menores de inviáveis e inférteis, porém, não diferiram em função do alimento fornecido ao predador na fase de larva.It was aimed to study some biological aspects in the adult stage of Chrysoperla externa (Hagen when the larvae of predator were fed both nymphs and adult females of Planococcus citri (Risso. The experiment was conducted in climate chamber at 25 ± 1°C, 70 ± 10% of RH and 12-h photophase. The adults of C. externa whose larvae were fed nymphs at the three instars and adult females of mealybug were separated by sex and 25 couples were individualized

  1. Biological cycle of Tenuipalpus heveae Baker (Acari, Tenuipalpidae on leaflets of three rubber tree clones Ciclo de vida de Tenuipalpus heveae Baker (Acari, Tenuipalpidae em folíolos de três clones de seringueira

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    Reinaldo José Fazzio Feres

    2010-06-01

    Full Text Available Life cycle of Tenuipalpus heveae Baker (Acari, Tenuipalpidae on leaflets from three rubber tree clones. The biological cycle of Tenuipalpus heveae Baker, 1945 (Tenuipalpidae, a potential rubber tree pest mite, was studied by the observation of individuals reared on leaflets of the clones GT 1, PB 235 and RRIM 600, in controlled environmental conditions. Three daily observations were done of 60 eggs on leaflets from each clone in order to verify the development of immature stages and the female oviposition. The fertility life table was constructed based in the collected data. Mites reared on PB 235 had faster rate of development, requiring less time in days, to double its population in number (TD, and had the highest values for egg production, female longevity, net reproductive rate (Ro, intrinsic rate of natural increase (r m and finite rate of increase (λ. Lower reproductive values and the longest time necessary to reach adult stage were recorded for the mites on GT 1. In all studied clones, the deutonymphal phase had the highest viability, while the larval phase had the lowest, highlighted by the survivorship curve that indicated high mortality during this life stage. The clone PB 235 allowed the most suitable conditions for the development of T. heveae, followed by RRIM 600, while GT 1 was the less suitable substratum to rear this mite species.O ciclo de vida de Tenuipalpus heveae Baker, 1945 (Tenuipalpidae, um potencial ácaro-praga da seringueira, foi estudado a partir de indivíduos criados sobre folíolos destacados dos clones GT 1, PB 235 e RRIM 600, em condições controladas. Três observações diárias foram realizadas, acompanhando-se o desenvolvimento de 60 ovos e de sua prole em folíolos de cada um dos clones, para verificação da oviposição das fêmeas e dos estágios de desenvolvimento. A partir dos dados obtidos, foi elaborada uma tabela de vida de fertilidade. Os ácaros criados sobre folíolos de PB 235 apresentaram r

  2. Characterization of the complete mitochondrial genome of the storage mite pest Tyrophagus longior (Gervais) (Acari: Acaridae) and comparative mitogenomic analysis of four acarid mites.

    Science.gov (United States)

    Yang, Banghe; Li, Chaopin

    2016-02-01

    Mites of the genus Tyrophagus are economically important polyphagous pest commonly living on stored products and also responsible for allergic reactions to humans. Complete mitochondrial genomes (mitogenomes) and the gene features therein are widely used as molecular markers in the study of population genetics, phylogenetics as well as molecular evolution. However, scarcity on the sequence data has greatly impeded the studies in these areas pertaining to the Acari (mites and ticks). Information on the Tyrophagus mitogenomes is quite critical for phylogenetic evaluation and molecular evolution of the mitogenomes within Acariformes. Herein, we reported the complete mitogenome of the allergenic acarid storage mite Tyrophagus longior (Astigmata: Acaridae), an important member of stored food pests, and compared with those of other three acarid mites. The complete mitogenome of T. longior was a circular molecule of 13,271 bp. Unexpectedly, only 19 transfer RNA genes (tRNAs) were present, lacking trnF, trnS1 and trnQ. Furthermore, it also contained 13 protein-coding genes (PCGs) and 2 genes for rRNA (rrnS and rrnL) commonly detected in metazoans. The four mitogenomes displayed similar characteristics with respect to the gene content, nucleotide comparison, and codon usages. Yet, the gene order of T. longior was different from that in other Acari. The J-strands of the four mitogenomes possessed high A+T content (67.4-70.0%), and exhibited positive GC-skews and negative AT-skews. Most inferred tRNAs of T. longior were extremely truncated, lacking either a D- or T-arm, as found in other acarid mites. In T. longior mitogenome the A+T-rich region was just 50 bp in length and can be folded as a stable stem-loop structure, whereas in the region some structures of microsatellite-like (AT)n and palindromic sequences was not present. Besides, reconstructing of the phylogenetic relationship based on concatenated amino acid sequences of 13 PCGs supported that monophyly of the family

  3. Diversity of Quill Mites of the Family Syringophilidae (Acari: Prostigmata) Parasitizing Owls (Aves: Strigiformes) With Remarks on the Host-Parasite Relationships.

    Science.gov (United States)

    Skoracki, Maciej; Unsoeld, Markus; Marciniak, Natalia; Sikora, Bozena

    2016-07-01

    The quill mite fauna of the family Syringophilidae (Acari: Prostigmata: Cheyletoidea) associated with owls (Aves: Strigiformes) is reviewed. A new genus is proposed, Neobubophilus Skoracki & Unsoeld gen. nov. It differs from closely related Bubophilus (Bubophilus Philips and Norton, 1978) by the absence of leg setae vsII in the both sexes. In addition, four new species are described: (1) Neobubophilus cunicularius Skoracki & Unsoeld sp. nov. from Athene cunicularia (Molina, 1782) (Strigidae) from Paraguay; (2) Neobubophilus atheneus Skoracki & Unsoeld sp. nov. from Athene noctua (Scopoli, 1769) and Athene brama (Temminck, 1821) (Strigidae), both from India; (3) Bubophilus tytonus Skoracki & Unsoeld sp. nov. from Tyto alba affinis (Blyth, 1862) (Tytonidae) from Cameroon, and (4) Megasyringophilus dalmas Skoracki & Unsoeld sp. nov. from Megascops choliba (Vieillot, 1817) (Strigidae) from Venezuela. The following new host species are given: Bubo bubo (Linnaeus, 1758) (Strigidae) from Nepal for Bubophilus ascalaphus (Philips and Norton 1978) and Strix woodfordii (Smith, 1834) (Strigidae) from Tanzania for Bubophilus aluconis (aluconis Nattress and Skoracki 2009). A key for syringophilid genera and species associated with owls is constructed. The host-parasite relationships of syringophilid mites and owls are discussed. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com Version of Record, first published online May 24, 2016 with fixed content and layout in compliance with Art. 8.1.3.2 ICZN.

  4. Toxicological evaluation of genetically modified cotton (Bollgard) and Dipel WP on the non-target soil mite Scheloribates praeincisus (Acari: Oribatida).

    Science.gov (United States)

    Oliveira, Anibal R; Castro, Thiago R; Capalbo, Deise M F; Delalibera, Italo

    2007-01-01

    Insecticides derived from the bacterium Bacillus thuringiensis (Bt) and plants genetically modified (GM) to express B. thuringiensis toxins are important alternatives for insect pest control worldwide. Risk assessment of B. thuringiensis toxins to non-target organisms has been extensively studied but few toxicological tests have considered soil invertebrates. Oribatid mites are one of the most diverse and abundant arthropod groups in the upper layers of soil and litter in natural and agricultural systems. These mites are exposed to the toxic compounds of GM crops or pesticides mainly when they feed on vegetal products incorporated in the soil. Although some effects of B. thuringiensis products on Acari have been reported, effects on oribatid mites are still unknown. This study investigated the effects of the ingestion of Bt cotton Bollgard and of the B. thuringiensis commercial product Dipel WP on the pantropical species Scheloribates praeincisus (Scheloribatidae). Ingestion of Bollgard and Dipel did not affect adult and immature survivorship and food consumption (estimated by number of fecal pellets produced daily) or developmental time of immature stages of S. praeincisus. These results indicate the safety of Bollgard and Dipel to S. praeincisus under field conditions where exposition is lower and other food sources besides leaves of Bt plants are available. The method for toxicological tests described here can be adapted to other species of Oribatida, consisting on a new option to risk assessment studies.

  5. Dinâmica populacional de Calepitrimerus vitis (Nalepa (Acari: eriophyidae em cultivares de videira na região da campanha do Rio Grande do Sul

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    Paulo Ricardo Ebert Siqueira

    2013-06-01

    Full Text Available Na Região da Campanha do Rio Grande do Sul, o ácaro-da-ferrugem-da-videira, Calepitrimerus vitis (Nalepa (Acari: Eriophyidae, é encontrado com frequência em vinhedos de cultivares europeias, desde a safra de 2004/2005, causando bronzeamento nas folhas. A dinâmica populacional de C. vitis nas cultivares Chardonnay e Merlot foi avaliada em vinhedo comercial localizado no município de Dom Pedrito, na região da Campanha, durante os anos agrícolas de 2005/2006 e 2006/2007, por meio de amostragem realizada em folhas das posições basal, intermediária e apical de ramos de produção. O pico populacional de C. vitis ocorre entre o final de fevereiro e o início de março, sendo seguido de forte declínio populacional. A infestação variou de intensidade entre as cultivares de acordo com o ano, sendo a cultivar Chardonnay mais infestada no primeiro ano, e Merlot, no segundo. Folhas na posição basal, mediana e apical apresentam níveis similares de infestação. Uma correlação positiva foi encontrada entre o número de C. vitis na face abaxial das folhas e o percentual de folhas com infestação.

  6. Toxicidade diferencial de produtos à base de abamectina ao ácaro Brevipalpus phoenicis (Geijskes, 1939 (Acari: Tenuipalpidae em citros Differential toxicity of abamectin based products over Brevipalpus phoenicis (Geijskes, 1939 (Acari: Tenuipalpidae mite in citrus

    Directory of Open Access Journals (Sweden)

    Daniel Júnior de Andrade

    2010-03-01

    Full Text Available O ácaro Brevipalpus phoenicis é uma das principais pragas dos citros por ser vetor do "Citrus Leprosis Virus" (CiLV, agente causal da leprose, uma das mais graves doenças da citricultura. Objetivou-se avaliar o efeito tóxico de produtos à base de abamectina sobre o ácaro B. phoenicis. Foram realizados um experimento de ação direta e três de ação residual no Laboratório de Acarologia do Departamento de Proteção de Plantas (Fitossanidade da FCAV - UNESP, Jaboticabal-SP. O delineamento adotado nos bioensaios foi o inteiramente casualizado, onde 10 tratamentos foram repetidos 7 vezes, sendo cada repetição composta por um fruto de laranja. Os tratamentos estudados (mL p.c./100 L de água foram: Acaramik a 20; 30; 40 e 50 mL; Vertimec a 30 e 40 mL; Abamectin Nortox a 30 e 40 mL; Tricofol a 77 mL e uma testemunha sem aplicação. Utilizaram-se frutos com presença de verrugose, que foram lavados e parcialmente parafinados, deixando-se uma área sem parafina, que foi circundada com cola entomológica para contenção dos ácaros. Transferiram-se 20 ácaros adultos B. phoenicis para cada fruto. No bioensaio de ação direta, a transferência foi realizada antes das aplicações e, nos bioensaios de ação residual, aos 5; 10 e 15 dias após a aplicação dos produtos. A aplicação dos produtos sobre os frutos foi realizada em Torre de Potter. Os resultados obtidos nos bioensaios evidenciaram que os melhores tratamentos foram: Tricofol a 77 mL, Acaramik a 40 e 50 mL e Vertimec a 40 mL. De forma geral, os produtos testados podem ser utilizados no controle do ácaro B. phoenicis.The mite Brevipalpus phoenicis (Geijskes, 1939 (Acari: Tenuipalpidae is one of the most important pests in Brazil citrus plantation, because it is the virus "Citrus Leprosis Virus" (CiLV vector, one of the most serious citrus plantation diseases. The purpose of this experiment was to evaluate the toxical effect of abamectin in the mite B. phoenicis. It was performed

  7. Elenco y biogeografía de los ácaros acuáticos (Acari, Parasitengona, Hydrachnidia de Sudamérica

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    Rosso de Ferradás, B.

    2005-12-01

    Full Text Available Checklist and catalog publications demonstrate a clear connection between basic taxonomy and biodiversity issues. According to some estimates, only 10-30% of all global species have been named. As in other fields, catalogs provide an important source of information concerning species diversity in freshwater ecology.

    South America is a continent dominated by freshwater ecosystems. The tremendous habitat diversity created by this landscape supports a high number of arthropods, including water mites, which belong to the hyperdiverse group Acari. South America has a substantial task ahead in cataloging its biodiversity.

    Much has been published on water mites in South America. In fact, according to Besch, water mites were the most studied with the exception of Europe up until the 1960’s. Most of the collections were conducted by two acarologists (Lundblad and Karl Viets during the 1940’s. Today, the collection, identification and description process of water mites is slower. In the 1980’s, the north-american acarologist D. R. Cook produced two lengthy papers about neotropical water mites in four regions of South America. Recently, several Argentine acarologists have published papers on water mites from diverse habitats and regions in South America.

    The catalog presented here includes information regarding 6 superfamilies, including 23 families in 118 genera of true water mites (Hydrachnidia, Parasitengona, Acari. It also includes the references concerning the species, distribution in various regions of South America and –as far as known– habitat.

    At present, there are 916 species from several authors cataloged in 11 countries in South America. The degree of knowledge varies greatly from country to country, with numerous entries for Brazil and none for French Guiana.

    Las publicaciones de catálogos y listados de especies determinan una clara conexión entre taxonomía básica y temas

  8. Long-Term Effects of Berberis thunbergii (Ranunculales: Berberidaceae) Management on Ixodes scapularis (Acari: Ixodidae) Abundance and Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) Prevalence in Connecticut, USA.

    Science.gov (United States)

    Williams, Scott C; Linske, Megan A; Ward, Jeffrey S

    2017-12-08

    Japanese barberry (Berberis thunbergii de Candolle; Ranunculales: Berberidaceae) is an exotic invasive shrub that escaped cultivation in the United States and is now permanently established in many eastern and midwestern states. This study examined the long-term impacts of Japanese barberry management on blacklegged tick (Ixodes scapularis Say; Acari: Ixodidae) abundances and associated prevalence of Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner; Spirochaetales: Spirochaetaceae), the etiologic agent of Lyme disease. At six locations across Connecticut, adult I. scapularis were sampled for up to 10 yr. At each location, we sampled an area where barberry infestations were unmanipulated, adjacent areas where barberry was virtually nonexistent, and areas where barberry was managed utilizing a variety of techniques. Barberry management reduced B. burgdorferi-infected adult I. scapularis (BBIAIS) abundances (191/ha ± 64 SE) over 6 yr to statistically indifferent from that of no barberry areas (140/ha ± 47 SE; P = 0.080) and significantly less than intact barberry stands (458/ha ± 80 SE; P = 0.026). Over 9 yr, BBIAIS abundances in managed barberry remained lower than intact barberry stands (P = 0.037), but increased to be significantly greater than no barberry areas (P = 0.007) as cover increased over time. Longer-term data further document that Japanese barberry infestations are favorable habitat for I. scapularis. Control of Japanese barberry and other invasives should be at least on a 5-yr rotation to maintain low levels of invasive cover and eliminate humidity refugia to expose juvenile I. scapularis to more hostile environmental conditions in the interest of public health. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Ability of two natural products, nootkatone and carvacrol, to suppress Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) in a Lyme disease endemic area of New Jersey.

    Science.gov (United States)

    Dolan, Marc C; Jordan, Robert A; Schulze, Terry L; Schulze, Christopher J; Manning, Mark Cornell; Ruffolo, Daniel; Schmidt, Jason P; Piesman, Joseph; Karchesy, Joseph J

    2009-12-01

    We evaluated the ability of the natural, plant-derived acaricides nootkatone and carvacrol to suppress Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae). Aqueous formulations of 1 and 5% nootkatone applied by backpack sprayer to the forest litter layer completely suppressed I. scapularis nymphs through 2 d. Thereafter, the level of reduction gradually declined to nootkatone was less effective, but at a 5% concentration, the level of control was similar or greater to that observed with I. scapularis through 21 d postapplication. Initial applications of 0.05% carvacrol were ineffective, but a 5% carvacrol formulation completely suppressed nymphs of both species through 2 d and resulted in significant reduction in I. scapularis and A. americanum nymphs through 28 and 14 d postapplication, respectively. Backpack sprayer applications of 5% nootkatone to the shrub and litter layers resulted in 100% control of I. scapularis adults through 6 d, but the level of reduction declined to 71.5% at 28 d postapplication. By contrast, high-pressure applications of 2% nootkatone to the litter layer resulted in 96.2-100% suppression of both I. scapularis and A. americanum nymphs through 42 d, whereas much lower control was obtained from the same formulation applied by backpack sprayer. Backpack sprayer application of a 3.1% nootkatone nanoemulsion resulted in 97.5-98.9 and 99.3-100% reduction in I. scapularis and A. americanum nymphs, respectively, at 1 d postapplication. Between 7 d and 35 d postapplication, the level of control varied between 57.1% and 92.5% for I. scapularis and between 78.5 and 97.1% for A. americanum nymphs. The ability of natural products to quickly suppress and maintain significant control of populations of these medically important ticks at relatively low concentrations may represent a future alternative to the use of conventional synthetic acaricides.

  10. Suppression of host-seeking Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) nymphs after dual applications of plant-derived acaricides in New Jersey.

    Science.gov (United States)

    Jordan, Robert A; Dolan, Marc C; Piesman, Joseph; Schulze, Terry L

    2011-04-01

    We evaluated the ability of dual applications of natural, plant-derived acaricides to suppress nymphal Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae) in a Lyme disease endemic area of New Jersey. An aqueous formulation of 2% nootkatone provided >90% control of I. scapularis through 7 d. Control declined to 80.9% at 14 d, and a second application was made that provided >95% control through the remaining 4 wk of the nymphal season. Nootkatone provided >90% control of A. americanum through 35 d postapplication. Applications of 2% carvacrol and EcoTrol T&O resulted in rapid knockdown of both tick species, but control declined significantly to 76.7 and 73.7%, respectively, after 14 d when a second application was made that extended control of both tick species to between 86.2 and 94.8% at 21 d. Subsequently, control declined steadily in all plots by 42 d postapplication except for I. scapularis in carvacrol-treated plots, where levels of control >90% were observed through 35 d. Of the three compounds tested, 2% nootkatone provided the most consistent results, with 96.5 and 91.9% control of I. scapularis and A. americanum through 42 and 35 d, respectively. The ability of plant-derived natural products to quickly suppress and maintain significant control of populations of these medically important ticks may represent a future alternative to the use of conventional synthetic acaricides. In addition, the demonstrated efficacy of properly-timed backpack sprayer application may enable homeowner access to these minimal-risk acaricides.

  11. A review of the ticks (Acari, Ixodida of Brazil, their hosts and geographic distribution - 1. The State of Rio Grande do Sul, Southern Brazil

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    Evans DE

    2000-01-01

    Full Text Available A review of the ticks (Acari, Ixodida of the State of Rio Grande do Sul, southern Brazil, was completed as a step towards a definitive list (currently indicated as 12 of such species, their hosts and distribution. The ticks: Argas miniatus (poultry, Ixodes loricatus (opossums, Amblyomma aureolatum (dogs, A. calcaratum (anteaters, A. cooperi (capybaras, A. nodosum (anteaters, A. tigrinum (dogs (Neotropical and Rhipicephalus sanguineus (dogs (introduced, cosmopolitan, Afrotropical were confirmed as present, in addition to the predominant, Boophilus microplus (cattle (introduced, pan-tropical, Oriental. Of the further 18 species thus far reported in the literature as present in the state, but unavailable for examination: only Ornithodoros brasiliensis (humans and their habitations (Neotropical, Ixodes affinis (deer (Nearctic/Neotropical and I. auritulus (birds (Nearctic/Neotropical/Afrotropical/ Australasian are considered likely; 13 species would benefit from corroborative local data but the majority appear unlikely; reports of A. maculatum (Nearctic/Neotropical, but circum-Caribbean are considered erroneous; the validity of A. fuscum is in doubt. The very recent, first known report of the tropical Anocentor nitens (horses(Nearctic/Neotropical, but still apparent absence of the tropical A. cajennense (catholic (Nearctic/Neotropical and the sub-tropical/temperate Ixodes pararicinus (cattle (Neotropical in Rio Grande do Sul are important for considerations on their current biogeographical distribution and its dynamics in South America. The state has relatively long established, introduced ("exotic", Old World tick species (B. microplus, R. sanguineus that continue to represent significant pests and disease vectors to their traditional, introduced domestic animal hosts, cattle and urban dogs. There are also indigenous, New World ticks (A. miniatus, O. brasiliensis, A. aureolatum, A. nitens, as both long established and possibly newly locally

  12. Chemicalome and metabolome profiling of polymethoxylated flavonoids in Citri Reticulatae Pericarpium based on an integrated strategy combining background subtraction and modified mass defect filter in a Microsoft Excel Platform.

    Science.gov (United States)

    Zeng, Su-Ling; Duan, Li; Chen, Bai-Zhong; Li, Ping; Liu, E-Hu

    2017-07-28

    Detection of metabolites in complex biological matrixes is a great challenge because of the background noise and endogenous components. Herein, we proposed an integrated strategy that combined background subtraction program and modified mass defect filter (MMDF) data mining in a Microsoft Excel platform for chemicalome and metabolome profiling of the polymethoxylated flavonoids (PMFs) in Citri Reticulatae Pericarpium (CRP). The exogenously-sourced ions were firstly filtered out by the developed Visual Basic for Applications (VBA) program incorporated in the Microsoft Office. The novel MMDF strategy was proposed for detecting both target and untarget constituents and metabolites based on narrow, well-defined mass defect ranges. The approach was validated to be powerful, and potentially useful for the metabolite identification of both single compound and homologous compound mixture. We successfully identified 30 and 31 metabolites from rat biosamples after oral administration of nobiletin and tangeretin, respectively. A total of 56 PMFs compounds were chemically characterized and 125 metabolites were captured. This work demonstrated the feasibility of the integrated approach for reliable characterization of the constituents and metabolites in herbal medicines. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. A specific interdomain interaction preserves the structural and binding properties of the ModA protein from the phytopathogen Xanthomonas citri domain interaction and transport in ModA.

    Science.gov (United States)

    Santacruz-Perez, Carolina; Pegos, Vanessa Rodrigues; Honorato, Rodrigo V; Verli, Hugo; Lindahl, Erik; Barbosa, João Alexandre Ribeiro Gonçalves; Balan, Andrea

    2013-11-01

    The periplasmic-binding proteins in ATP-binding cassette systems (ABC Transporters) are responsible for the capture and delivery of ligands to their specific transporters, triggering a series of ATP-driven conformational changes that leads to the transport of the ligand. Structurally consisting of two lobes, the proteins change conformation after interaction with the ligand. The structure of the molybdate-binding protein (ModA) from Xanthomonas citri, bound to molybdate, was previously solved by our group and an interdomain interaction, mediated by a salt bridge between K127 and D59, apparently supports the binding properties and keeps the domains closed. To determinate the importance of this interaction, we built two ModA mutants, K127S and D59A, and analysed their functional and structural properties. Based on a set of spectroscopic experiments, crystallisation trials, structure determination and molecular dynamics (MD) simulations, we showed that the salt bridge is essential to maintain the structure and binding properties. Additionally, the MD simulations revealed that this mutant adopted a more compact structure that packed down the ligand-binding pocket. From the closed bound to open structure, the positioning of the helices forming the dipole and the salt bridge are essential to induce an intermediate state. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Chelicerata: Acari II

    NARCIS (Netherlands)

    Di Sabatino, A.; Gerecke, R.; Gledhill, T.; Smit, H.

    2010-01-01

    Chelicerata are a basically terrestrial group of invertebrates, including many clades whose representatives have never found an evolutionary way to aquatic live. An exception is made by some spiders and the highly diverse aquatic mites which in inland water habitats are represented by members of

  15. The effect of pre spring spray to reduce of citrus important pests.

    Science.gov (United States)

    Hashemi, B; Damavandian, M R; Shoushtaril, R Vafaei; Tafaghodynia, B

    2008-10-01

    The importance of pre spring spray against citrus aphids, Pulvinaria aurantii Cockerell and Panonychus citri McGregor that are the most important pest of citrus during spring was tested. In this research, 150 trees ten years old sweet orange (Thomson navel on Citrus aurantium (root stocks)) in a citrus orchard approximately three hectares sampled. The experiment was laid out in a totally randomized (one-way) design replicated five times. According to the results, the pre spring spray do not effect on population density of citrus aphids and P. aurantii during March, April, May and June. However, the P. citri population decreased. Therefore, it seems the pre spring spray in citrus orchards is not necessary, but if P. citri is observed, the pre spring spray should be recommended.

  16. Effects of powdery mildew fungicide programs on twospotted spider mite (Acari: Tetranychidae), hop aphid (Hemiptera: Aphididae), and their natural enemies in hop yards.

    Science.gov (United States)

    Gent, D H; James, D G; Wright, L C; Brooks, D J; Barbour, J D; Dreves, A J; Fisher, G C; Walton, V M

    2009-02-01

    Twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), and hop aphid, Phorodon humuli (Schrank) (Hemiptera: Aphididae), are the most important arthropod pests of hop (Humulus lupulus L.) in the Northern Hemisphere. A potential barrier for greater adoption of conservation biological control strategies for spider mites and hop aphid is the extensive use of fungicides for management of hop powdery mildew, Podosphaera macularis (Wallr.:Fr.) U. Braun & S. Takamatsu. Field studies conducted in experimental plots in Oregon and Washington in 2005 and 2006 quantified the effects of powdery mildew fungicide programs (i.e., sulfur, paraffinic oil, and synthetic fungicides) on arthropod pests and natural enemies on hop. Fungicide treatment significantly affected spider mite populations in all four studies. Multiple applications of sulfur fungicides applied before burr development resulted in 1.4-3.3-fold greater spider mite populations during summer. Near the cessation of the sulfur applications, or after a lag of 20-30 d, spider mite populations increased significantly faster on sulfur treated plants compared with water-treated plants in three of four experiments. The effect of paraffinic oil on spider mites was varied, leading to exacerbation of spider mites in Oregon and Washington in 2005, suppression of mites in Oregon in 2006, and no significant effect compared with water in Washington in 2006. Significant relative treatment effects for cone damage due to spider mite feeding were detected in Oregon in 2005 in plots treated with sulfur and paraffinic oil compared with water and synthetic fungicides. Mean populations of hop aphids were similar among treatments in Oregon, although sulfur treatment suppressed hop aphid populations in Washington in 2005 and 2006. Populations of individual predacious insect species and cumulative abundance of macropredators were not consistently suppressed or stimulated by treatments in all trials. However, predatory mite

  17. Differences in Stylet Sheath Occurrence and the Fibrous Ring (Sclerenchyma) between xCitroncirus Plants Relatively Resistant or Susceptible to Adults of the Asian Citrus Psyllid Diaphorina citri (Hemiptera: Liviidae)

    Science.gov (United States)

    Ammar, El-Desouky; Richardson, Matthew L.; Abdo, Zaid; Hall, David G.; Shatters, Robert G.

    2014-01-01

    The Asian citrus psyllid (ACP, Diaphorina citri, Hemiptera: Liviidae), is the principal vector of the phloem-limited bacteria strongly associated with huanglongbing (HLB), the world’s most serious disease of citrus. Host plant resistance may provide an environmentally safe and sustainable method of controlling ACP and/or HLB. Two xCitroncirus accessions (hybrids of Poncirus trifoliata and Citrus spp.), that are relatively resistant (UN-3881) or relatively susceptible (Troyer-1459) to ACP adults with regard to adult longevity, were compared in relation to ACP feeding behavior and some structural features of the leaf midrib. The settling (putative feeding/probing) sites of ACP adults on various parts of the leaf were not influenced primarily by plant accession. However, fewer ACP stylet sheaths were found in the midrib and fewer stylet sheath termini reached the vascular bundle (phloem and/or xylem) in UN-3881 compared to Troyer-1459 plants. Furthermore, in midribs of UN-3881 leaves the fibrous ring (sclerenchyma) around the phloem was significantly wider (thicker) compared to that in midribs of Troyer-1459 leaves. Our data indicate that feeding and/or probing by ACP adults into the vascular bundle is less frequent in the more resistant (UN-3881) than in the more susceptible (Troyer-1459) accessions. Our results also suggest that the thickness of the fibrous ring may be a barrier to stylet penetration into the vascular bundle, which is important for successful ACP feeding on the phloem and for transmitting HLB-associated bacteria. These results may help in the development of citrus plants resistant to ACP, which in turn could halt or slow the spread of the HLB-associated bacteria by this vector. PMID:25343712

  18. Differences in stylet sheath occurrence and the fibrous ring (sclerenchyma between xCitroncirus plants relatively resistant or susceptible to adults of the Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae.

    Directory of Open Access Journals (Sweden)

    El-Desouky Ammar

    Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri, Hemiptera: Liviidae, is the principal vector of the phloem-limited bacteria strongly associated with huanglongbing (HLB, the world's most serious disease of citrus. Host plant resistance may provide an environmentally safe and sustainable method of controlling ACP and/or HLB. Two xCitroncirus accessions (hybrids of Poncirus trifoliata and Citrus spp., that are relatively resistant (UN-3881 or relatively susceptible (Troyer-1459 to ACP adults with regard to adult longevity, were compared in relation to ACP feeding behavior and some structural features of the leaf midrib. The settling (putative feeding/probing sites of ACP adults on various parts of the leaf were not influenced primarily by plant accession. However, fewer ACP stylet sheaths were found in the midrib and fewer stylet sheath termini reached the vascular bundle (phloem and/or xylem in UN-3881 compared to Troyer-1459 plants. Furthermore, in midribs of UN-3881 leaves the fibrous ring (sclerenchyma around the phloem was significantly wider (thicker compared to that in midribs of Troyer-1459 leaves. Our data indicate that feeding and/or probing by ACP adults into the vascular bundle is less frequent in the more resistant (UN-3881 than in the more susceptible (Troyer-1459 accessions. Our results also suggest that the thickness of the fibrous ring may be a barrier to stylet penetration into the vascular bundle, which is important for successful ACP feeding on the phloem and for transmitting HLB-associated bacteria. These results may help in the development of citrus plants resistant to ACP, which in turn could halt or slow the spread of the HLB-associated bacteria by this vector.

  19. Primera aproximacion a la Paleoentomología de los yacimientos de la Sierra de Atapuerca (Burgos, España: la fauna subfósil de Oribátidos (Acari, Oribatida

    Directory of Open Access Journals (Sweden)

    Arroyo, J.

    2007-06-01

    Full Text Available The Atapuerca Quaternarian sites are of worldwide interest due to the presence of human remains belonging to the last million years. The oribatid mites (Acari, Oribatida found in several archaeological samples extracted from the Atapuerca Quaternarian deposits, have been analyzed during the 2003 excavation campaign to study the Palaeoentomology of the site. The oribatid mite fauna consists of 7 individuals, 6 of which were obtained from Gran Dolina site (about 300.000 years old and belong to families Cosmochthoniidae, Scheloribatidae, Oribatulidae and Hemileiidae. Most of the taxa were identified to species level. The results obtained were used as a basis to reconstruct the paleo-environments of the site in correspondence with the biological and ecological preferences of the taxa.

    Los yacimientos cuaternarios de la Sierra de Atapuerca ofrecen interés mundial por haber hospedado varias especies de homínidos que vivieron en el último millón de años. En este contexto, durante la campaña de excavaciones de 2003 se realizó un muestreo puntual en algunos de sus yacimientos para obtener los primeros datos de restos de artrópodos que pudieran conservarse en los mismos. En este trabajo se presentan los resultados obtenidos de ácaros subfósiles pertenecientes al suborden de los oribátidos (Acari, Oribatida. Después de procesar los sedimentos, se obtuvieron un total de 7 individuos en el conjunto de los yacimientos muestreados, de los cuales 6 aparecieron en Gran Dolina en un nivel con datación en torno a los 300.000 años. Los ejemplares, identificados en su mayoría a nivel taxonómico de especie, pertenecen a las familias Cosmochthoniidae, Scheloribatidae, Oribatulidae y Hemileiidae. Dado el conocimiento que se dispone de la biología de los taxones encontrados, que pertenecen a géneros y especies presentes en la actualidad, se han realizado inferencias sobre los ambientes pretéritos en que los animales vivieron.

  20. Chlorotic spots on Clerodendrum, a disease caused by a nuclear type of Brevipalpus (Acari:Tenuipalpidae transmitted virus Mancha clorótica do Clerodendrum, uma enfermidade causada por um vírus do tipo nuclear, transmitido pelo ácaro Brevipalpus phoenicis (Acari:Tenuipalpidae

    Directory of Open Access Journals (Sweden)

    Elliot Watanabe Kitajima

    2008-02-01

    Full Text Available Chlorotic spots have been observed in plants of Clerodendrum x speciosum growing in residential gardens and parks in Piracicaba, SP, Brazil. Thin sections of diseased tissues revealed characteristic cytopathic effects of the nuclear type of the Brevipalpus (Acari: Tenuipalpidae mite-transmitted viruses (BTrV. Brevipalpus mites, identified as B. phoenicis, infesting symptomatic C. x speciosum plants transmitted the pathogen to healthy C. x speciosum and to C. thomsonae, Gomphrena globosa, Hibiscus cannabinus, H. coccineus, H. schizopetalus, Salvia leucantha, Spathiphyllum wallasi and Tetragonia expansa causing chlorotic spots on their leaves. Mechanical inoculation using leaf extracts from infected C. x speciosum resulted in chlorotic spots on inoculated C. x speciosum, Chenopodium quinoa, C. amaranticolor, G. globosa, H. cannabinus, H. coccineus and T. expansa leaves. C. amaranticolor and C. quinoa kept at 28 - 30°C became systemically infected. The same cytopathic effects caused by the nuclear type of BTrV were seen in tissues from all infected test plants by electron microscopy. The virus was purified from systemically infected leaves of C. amaranticolor and C. quinoa. A polyclonal antiserum obtained from an immunized rabbit presented a strong reaction with the homologous antigen in ELISA tests. The results suggest that this chlorotic spot disease of C. x speciosum is caused by a new species of the nuclear type of BTrV, tentatively named Clerodendrum chlorotic spot virus (ClCSV.Manchas cloróticas e necróticas foram observadas em folhas de várias plantas de coração-sangrento (Clerodendrum x speciosum cultivadas em parques e jardins em Piracicaba, SP, associadas à infestação pelo ácaro tenuipalpídeo Brevipalpus phoenicis. Exames preliminares de secções de tecido das manchas cloróticas ao microscópio eletrônico revelaram a ocorrência de efeitos citopáticos característicos dos induzidos pelos vírus do tipo nuclear, transmitido

  1. Influence de l'usage préventif des pesticides sur les acariens Tetranychus urticae et Phytoseiulus persimilis (Acari : Tetranychidae, Phytoseiidae présents en cultures de fraisiers du Nord du Maroc

    Directory of Open Access Journals (Sweden)

    Lagziri, M.

    2015-01-01

    Full Text Available Influence of previous pesticide use on Tetranychus urticae and Phytoseiulus persimilis (Acari: Tetranychidae, Phytoseiidae from strawberry crops in the north of Morocco. Description of the subject. Effects of recommended doses of five common pesticides in the strawberries of Loukkos area (Morocco were tested on the two-spotted spider mite Tetranychus urticae and its predatory mite Phytoseiulus persimilis. Laboratory study assessed the contact toxicity of one avermectin miticide (abamectin, two pyrethrinoid insecticide-acaricides (bifenthrin and lambda-cyalothrin, and two fungicides: firstly, mancozeb, which belongs to the dithiocarbamates family of chemicals and secondly, hexaconazole, of the triazole family. Objectives. The aim of the present study was to test in laboratory conditions the effect of five pesticides on the two-spotted spider mite, T. urticae and its predatory mite, P. persimilis. The five pesticides tested were those most frequently applied for at least two years on strawberries at the experimental site. Method. Bioassays were performed with populations of mites originating from different plots with various crop protection backgrounds. The first group of plots had been repeatedly treated with the five tested pesticides during a two-year period, the second group had been moderately treated, and the third had been treated once with the tested pesticides. Results. Our results showed that the tested pesticides provided effective control of T. urticae but that they were not compatible with use on the predatory mite P. persimilis, as these particular mites did not usually come into contact with these products. On the other hand, in plots where pesticides had been used for a long time, the susceptibility of P. persimilis populations to these products was significantly reduced. Conclusions. If the tested pesticides are to be considered for integrated pest control programs in plots where they have been used for a long time and where P

  2. Chemical composition and acaricidal activity of the essential oil of Baccharis dracunculifolia De Candole (1836) and its constituents nerolidol and limonene on larvae and engorged females of Rhipicephalus microplus (Acari: Ixodidae).

    Science.gov (United States)

    de Assis Lage, Tiago Coelho; Montanari, Ricardo Marques; Fernandes, Sergio Antonio; de Oliveira Monteiro, Caio Márcio; de Oliveira Souza Senra, Tatiane; Zeringota, Viviane; da Silva Matos, Renata; Daemon, Erik

    2015-01-01

    Baccharis dracunculifolia DC (common name "alecrim-do-campo" in Brazil) is a plant with widespread distribution in South America that is the botanical origin of green propolis. The aim of this study was to evaluate the chemical composition and acaricidal activity of the essential oil of B. dracunculifolia and its constituents nerolidol and limonene on unengorged larvae and engorged females of Rhipicephalus microplus (Acari: Ixodidae). The essential oil yield was 0.8% of dry mass and the major constituents were nerolidol (22.3%), germacrene D (7.2%), limonene (6.9%), β-pinene (6.7) and bicyclogermacrene (6.5%). The acaricidal activity of the essential oil and the pure compounds nerolidol and (R)-(+)-limonene were assessed in the laboratory through the modified larval packet test (LPT) and the female immersion test (FIT). In the LPT, the essential oil and nerolidol were both active, causing more than 90% mortality at concentrations from 15.0 and 10.0 mg mL(-1), respectively, whereas (R)-(+)-limonene was not active. In the FIT, the oil and nerolidol caused reduction in the quantity and quality of eggs produced, with control percentages of 96.3% and 90.3% at concentrations of 60.0 and 50.0 mg mL(-1), respectively. It can be concluded that the essential oil obtained from the aerial parts of B. dracunculifolia and its major component nerolidol have high activity on R. microplus larvae and engorged females. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Nouvelle technique d'élevage de l'acarien phyllophage Tetranychus urticae Koch (Acari : Tetranychidae et son application à l'étude de l'efficacité de quelques acaricides sur pomme de terre (Solarium tuberosum L.

    Directory of Open Access Journals (Sweden)

    Badegana, AM.

    2000-01-01

    Full Text Available A New Rearing Technique of Phytophagous Mite Tetranychus urticae Koch (Acari : Tetranychida and its Application in the Study of the Efficacy of some Acaricides on Potato [Solanum tuberosum L.. A 5 cm diameter leaf disc of potato or another host plant (or four on 2.5 cm diameter was used in a Petri dish of 9 cm diameter for the rearing technique. This leaf disc, pierced in its centre, slides along a rustproof pin and floats on a 1 mm thick lamina of demineralized fresh water. Water is a "strong barrier" which confines the tetranychid mites on the leaf disc, even if this one does not corne from a host plant (tetranychid mites deprived of food. This rearing technique was used as a bioassay to test the effectiveness of acaricides (pyrimiphos-methyl, bromopropylate, fenpropathrin, dienochlor on the developmental stages of Tetranychus urticae. The ovicidal activity against the eggs of one, three, seven days old (the eggs incubation duration being 8.1 ±0.15 days was also studied. The results obtained show that bromopropylate, fenpropathrin and dienochlor have an ovicidal activity against the eggs of the different ages, but dienochlor has the highest efficiency (90 % mortality. Pyrimiphos-methyl is only active against the seven-day old eggs and bromopropylate has a high efficiency only on the one-day old eggs. Concerning the other developmental stages such as chrysalis (protochrysalis, deu-tochrysalis, teleiochrysalis and mobile stages (larva, protonymph, deutonymph and adult female, pyrimiphos-methyl has de highest efficiency (90 % mortality ; dienochlor also, except mobile stages. Bromopropylate has no activity against the chrysalis and mobile stages and fenpropathrin has a remarkable repulsive effect.

  4. The type III protein secretion system contributes to Xanthomonas citri subsp. citri biofilm formation

    KAUST Repository

    Zimaro, Tamara; Thomas, Ludivine; Marondedze, Claudius; Sgro, Germá n G; Garofalo, Cecilia G; Ficarra, Florencia A; Gehring, Christoph A; Ottado, Jorgelina; Gottig, Natalia

    2014-01-01

    Background: Several bacterial plant pathogens colonize their hosts through the secretion of effector proteins by a Type III protein secretion system (T3SS). The role of T3SS in bacterial pathogenesis is well established but whether this system

  5. New Neoribates (Acari, Oribatida, Parakalummidae) from Vietnam

    Czech Academy of Sciences Publication Activity Database

    Ermilov, S.G.; Starý, Josef

    2017-01-01

    Roč. 4303, č. 1 (2017), s. 51-72 ISSN 1175-5326 Institutional research plan: CEZ:AV0Z60660521 Institutional support: RVO:60077344 Keywords : Oripodoidea * morphology * systematics * Tam Dao National Park * Oriental region Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 0.972, year: 2016

  6. New Protoribates (Acari, Oribatida, Haplozetidae) from Vietnam

    Czech Academy of Sciences Publication Activity Database

    Ermilov, S.G.; Starý, Josef

    2017-01-01

    Roč. 4258, č. 6 (2017), s. 501-524 ISSN 1175-5326 Institutional research plan: CEZ:AV0Z60660521 Institutional support: RVO:60077344 Keywords : Oripodoidea * morphology * systematics * new species * Tam Dao National Park * Oriental region Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 0.972, year: 2016

  7. fabricius (acari: ixodidae en equinos y bovinos

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    Víctor Álvarez C.

    2007-01-01

    Full Text Available Con el objetivo de ampliar el conocimiento sobre el comportamiento de los adultos y las ninfas de Amblyomma en equinos y bovinos, se desarrolló un estudio en San Pablo de Turrubares, provincia de San José. Para el trabajo de campo se empleó 3 métodos: revisión de los animales seleccionados, el arrastre por medio de bandera, y el trampeo con CO2. Los equinos demostraron ser la especie más susceptible para A. cajennense, seguidos por B. taurus. Las ninfas de A. cajennense se concentran en la época seca y a nivel de laboratorio muestran indicadores que colocan a estas garrapatas como individuos con una gran capacidad para sobrevivir sin alimento, lo que dificulta su control. No se encontró correlación entre la precipitación y los niveles de garrapatas; sin embargo, durante la época que incluye la mayoría de los meses lluviosos se encontró una mayor cantidad de garrapatas. Se observó sitios de preferencia por parte de A. cajennense para fijarse al cuerpo de los animales.

  8. A revision of the Plateremaeidae (Acari: Oribatei

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    Adilson D. Paschoal

    1986-01-01

    Full Text Available The family Plateremaeidae is revised, and includes the following taxa: Plateremaeus Berlese, with the only species P. ornatissimus (Berlese, from Brazil; Allodamaeus Banks, with the species ewingi (Banks, from the USA, coralgablensis, sp. n. (type-locality: USA, Flórida, Coral Gables, and ornatos Balogh & Csiszár, from Argentina; Lophoremaeus, gen. n., with two species: mirabilis Csiszár, from Bulgaria, the type-species, and laminipes (Berlese, n. comb., from Italy; Paralopheremaeus, gen. n., with the species legendrei (Balogh, n. comb., from Madagascar; Calipteremaeus, gen. n., with the species yaginumai (Aoki, n. comb., from Japan; the following species are considered incertae sedis: Plateremaeus carinulatus (Berlese, from Brasil, P. complanatus (Berlese, from Chile, P. rotundatus Berlese, from Japan, and P. tunicatus ( Balogh, from Zaire.A família Plateremaeidae é revista, e inclui os seguintes táxons: Plateremaeus Berlese, com a única espécie P. ornatissimus (Berlese, do Brazil; Allodamaeus Banks, com as espécies ewingi (Banks, dos Estados Unidos, coralgablensis, sp. n. (localidade-tipo: Estados Unidos, Flórida, Coral Gables e ornatos Balogh & Csziszár, da Argentina; Lophoremaeus, gen. n., com duas espécies: mirabilis Csiszár, da Bulgária, espécie-tipo, e laminipes (Berlese, n. comb., da Itália; Paralopheremaeus, gen. n., com a espécie legendrei (Balogh, n. comb., de Madagascar; Calipteremaeus. gen. n., com a espécie yaginumai (Aoki, n. comb., do Japão; as seguintes espécies são consideradas incertae sedis: Plateremaeus carinulatus (Berlese, do Brasil, P. complanatus (Berlese, do Chile, P. rotundatus Berlese, do Japão, e P. tunicatus (Balogh, do Zaire.

  9. Diurnal temperature variations affect development of a herbivorous arthropod pest and its predators.

    Directory of Open Access Journals (Sweden)

    Dominiek Vangansbeke

    Full Text Available The impact of daily temperature variations on arthropod life history remains woefully understudied compared to the large body of research that has been carried out on the effects of constant temperatures. However, diurnal varying temperature regimes more commonly represent the environment in which most organisms thrive. Such varying temperature regimes have been demonstrated to substantially affect development and reproduction of ectothermic organisms, generally in accordance with Jensen's inequality. In the present study we evaluated the impact of temperature alternations at 4 amplitudes (DTR0, +5, +10 and +15°C on the developmental rate of the predatory mites Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus McGregor (Acari: Phytoseiidae and their natural prey, the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae. We have modelled their developmental rates as a function of temperature using both linear and nonlinear models. Diurnally alternating temperatures resulted in a faster development in the lower temperature range as compared to their corresponding mean constant temperatures, whereas the opposite was observed in the higher temperature range. Our results indicate that Jensen's inequality does not suffice to fully explain the differences in developmental rates at constant and alternating temperatures, suggesting additional physiological responses play a role. It is concluded that diurnal temperature range should not be ignored and should be incorporated in predictive models on the phenology of arthropod pests and their natural enemies and their performance in biological control programmes.

  10. Diurnal Temperature Variations Affect Development of a Herbivorous Arthropod Pest and its Predators

    Science.gov (United States)

    Vangansbeke, Dominiek; Audenaert, Joachim; Nguyen, Duc Tung; Verhoeven, Ruth; Gobin, Bruno; Tirry, Luc; De Clercq, Patrick

    2015-01-01

    The impact of daily temperature variations on arthropod life history remains woefully understudied compared to the large body of research that has been carried out on the effects of constant temperatures. However, diurnal varying temperature regimes more commonly represent the environment in which most organisms thrive. Such varying temperature regimes have been demonstrated to substantially affect development and reproduction of ectothermic organisms, generally in accordance with Jensen’s inequality. In the present study we evaluated the impact of temperature alternations at 4 amplitudes (DTR0, +5, +10 and +15°C) on the developmental rate of the predatory mites Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus McGregor (Acari: Phytoseiidae) and their natural prey, the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae). We have modelled their developmental rates as a function of temperature using both linear and nonlinear models. Diurnally alternating temperatures resulted in a faster development in the lower temperature range as compared to their corresponding mean constant temperatures, whereas the opposite was observed in the higher temperature range. Our results indicate that Jensen’s inequality does not suffice to fully explain the differences in developmental rates at constant and alternating temperatures, suggesting additional physiological responses play a role. It is concluded that diurnal temperature range should not be ignored and should be incorporated in predictive models on the phenology of arthropod pests and their natural enemies and their performance in biological control programmes. PMID:25874697

  11. Insights into xanthomonas axonopodis pv. Citri biofilm through proteomics

    KAUST Repository

    Zimaro, Tamara; Thomas, Ludivine; Marondedze, Claudius; Garavaglia, Betiana S; Gehring, Christoph A; Ottado, Jorgelina; Gottig, Natalia

    2013-01-01

    in adherence were over-expressed, while a polynucleotide phosphorylase that was demonstrated to negatively control biofilm formation in E. coli was down-regulated. In addition, several proteins involved in protein synthesis, folding and stabilization were up

  12. Artificial Neural Network Analysis of Xinhui Pericarpium Citri ...

    African Journals Online (AJOL)

    Methods: Artificial neural networks (ANN) models, including general regression neural network (GRNN) and multi-layer ... N-hexane (HPLC grade) was purchased from. Fisher Scientific. ..... Simultaneous Quantification of Seven Flavonoids in.

  13. In vitro control of Alternaria citri using antifungal potentials of ...

    African Journals Online (AJOL)

    msc06-08

    2012-05-24

    May 24, 2012 ... black-pod disease (Phytophthora palmivora) of cacao. Biol. Control,. 50:143-149. Hanhong B (2011). Trichoderma species as abiotic and biotic stress · quenchers in plants. Res. J. Biotechnol., 6(3): 73-79. Harman GE (2000). Myths and dogmas of biocontrol: Changes in perceptions derived from research ...

  14. Caracterização de um vírus baciliforme isolado de Solanum violaefolium transmitido pelos ácaros Brevipalpus phoenicis e Brevipalpus obovatus (Acari: Tenuipalpidae Characterization of a bacilliform virus isolated from Solanum violaefolium transmitted by the tenuipalpid mites Brevipalpus phoenicis and Brevipalpus obovatus

    Directory of Open Access Journals (Sweden)

    Paulo de Tarso Oliveira Ferreira

    2007-09-01

    Full Text Available Solano-violeta (Solanum violaefolium é uma planta ornamental rasteira usada para cobrir solos de áreas sombreadas. Um vírus que induz manchas anelares nas folhas desta planta, tentativamente designado Solanum violaefolium ringspot virus - SvRSV, transmitido pelo ácaro Brevipalpus phoenicis (Acari: Tenuipalpidae foi encontrado em Piracicaba, SP. Trata-se de um vírus baciliforme que se assemelha a outros vírus do tipo citoplasmático transmitidos por Brevipalpus sp. Este trabalho teve como objetivo relatar propriedades biológicas e estabelecer uma caracterização molecular parcial do SvRSV. O vírus pode ser transmitido mecanicamente a várias outras espécies botânicas, causando lesões localizadas. Entre as espécies avaliadas, Datura stramonium mostrou-se a melhor hospedeira experimental. Observou-se também a manifestação de sintomas nestas plantas após infestação das mesmas por B. obovatus previamente alimentado em lesões de SvRSV, confirmando esta outra espécie de ácaro como vetor do vírus. Suas propriedades físicas in vitro foram: temperatura de inativação 40-45 ºC; ponto final de diluição 10-3-10-4; longevidade in vitro 12 dias. Em secções ultrafinas, as partículas do SvRSV mostraram-se levemente mais delgadas e mais longas que as de outros vírus do mesmo grupo. A partir do dsRNA do SvRSV foi construída uma biblioteca de cDNA e foram identificadas duas possíveis regiões codificadoras das proteínas de movimento e replicase viral. Baseado nestas regiões foram desenhados "primers" para amplificação do RNA do SvRSV por RT-PCR. Sondas baseadas nas seqüências obtidas hibridizaram com ss- e dsRNA de D. stramonium infectadas pelo vírus. Ensaios preliminares de RT-PCR e hibridização não resultaram em reação com o vírus da leprose dos citros, tipo citoplasmático (CiLV-C.Solanum violaefolium is an ornamental plant, with prostrate, trailing growth habit and is cultivated in shaded areas. A virus that causes

  15. Toxicity of plant essential oils to Tetranychus urticae (Acari: Tetranychidae) and Phytoseiulus persimilis (Acari: Phytoseiidae).

    Science.gov (United States)

    Choi, Won-Il; Lee, Sang-Geui; Park, Hyung-Man; Ahn, Young-Joon

    2004-04-01

    Fifty-three plant essential oils were tested for their toxicity against eggs and adults of Tetranychus urticae Koch as well as adults of Phytoseiulus persimilis Athias-Henriot, by using a filter paper diffusion bioassay without allowing direct contact. Responses varied according to oil type and dose, and mite species. In a plastic container (4.5 by 9.5 cm) bioassay at 14 x 10(-3) microl/ml air, caraway seed, citronella java, lemon eucalyptus, pennyroyal, and peppermint oils gave > 90% mortality against adult T. urticae, whereas 82 and 81% mortality was observed with sage and spearmint oils, respectively. With the exception of sage oil, the other six essential oils were highly effective against T. urticae eggs at 9.3 x 10(-3) microl/ml air. Against adult P. persimilis, these six test oils caused > 90% mortality at 7.1 x 10(-3) microl/ml air. Particularly peppermint oil at 4.7 x 10(-3) microl/ml air was highly toxic. In an acrylic cage (30 by 30 by 40 cm ) test, lemon eucalyptus, pennyroyal, peppermint, and spearmint oils were highly effective against adult T. urticae at 1.4 x 10(-3) microl/ml air. These results indicate that the mode of delivery of these essential oils was largely a result of action in the vapor phase via the respiratory system. The essential oils described herein merit further study as potential fumigants for T. urticae control.

  16. Motivation Theories of Maslow, Herzberg, McGregor & McClelland. A Literature Review of Selected Theories Dealing with Job Satisfaction and Motivation.

    Science.gov (United States)

    Pardee, Ronald L.

    Job satisfaction, motivation, and reward systems are included in one area of organizational theory. The strongest influence in this area is motivation because it overlaps into both of the other two components. A review of the classical literature on motivation reveals four major theory areas: (1) Maslow's Hierarchy of Needs; (2) Herzberg's…

  17. Toxicidade de extratos de nim (Azadirachta indica ao ácaro-vermelho-do-cafeeiro Oligonychus ilicis Toxicity of neem extracts (Azadirachta indica to the coffee red mite Oligonychus ilicis

    Directory of Open Access Journals (Sweden)

    Sheila Abreu Mourão

    2004-08-01

    Full Text Available O objetivo deste trabalho foi estudar a toxicidade aguda e crônica de extratos de óleo de torta, de sementes e de folhas de Azadirachta indica A. Juss (nim a fêmeas do ácaro-vermelho-do-cafeeiro Oligonychus ilicis (McGregor (Acari: Tetranychidae. A mortalidade e a taxa instantânea de crescimento populacional de fêmeas adultas desse ácaro foram avaliadas em discos de folhas de cafeeiro com 3,5 cm de diâmetro, impregnados com resíduo seco dos extratos de nim e flutuando em água. As concentrações dos extratos de óleo de torta, sementes e folhas de nim que mataram 50% e 99% dos indivíduos de O. ilicis, após 72 horas de exposição, foram de 0,02, 15,9 e 121,4 mg/mL e de 10,9, 520,9 e 277,4 mg/mL, respectivamente. A taxa instantânea de crescimento populacional de O. ilicis diminuiu, linearmente, com o aumento da concentração dos extratos de óleo de torta, sementes e folhas de nim até 0,075, 15 e 144 mg/mL, respectivamente, a partir das quais as populações desse ácaro foram extintas.The objective of this work was to study the toxicity of extracts of oil cake, seeds and leaves of Azadirachta indica A. Juss (neem to the coffee red mite Oligonychus ilicis (McGregor (Acari: Tetranychidae. Concentration-mortality and instantaneous rate of populational growth were determined for adult females of the red mite on disks of coffee with 3.5 cm diameter, floating on water and impregnated with dry residues of the neem extracts. Concentrations of these extracts which caused 50% mortality of the individuals of O. ilicis were 0.02, 15.9 and 121.4 mg/mL; while 99% mortality of this mite was reached with 10.9, 520.9 and 277.4 mg/mL for oil cake, seeds and leaves extracts, respectively. The instantaneous rate of populational growth of O. ilicis dropped as the extract doses increased up to 0.075, 15 and 144 mg/mL for oil cake, seeds and leaves extracts, respectively.

  18. THE INFLUENCE OF VARIABLE TEMPERATURE AND HUMIDITY ON THE PREDATION EFFICIENCY OF P. PERSIMILIS, N. CALIFORNICUS AND N. FALLACIS.

    Science.gov (United States)

    Audenaert, J; Vangansbeke, D; Verhoeven, R; De Clercq, P; Tirry, L; Gobin, B

    2014-01-01

    Predatory mites like Phytoseiulus persimilis Athias-Henriot, Neoseiulus californicus McGregor and N. fallacis (Garman) (Acari: Phytoseiidae) are essential in sustainable control strategies of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) in warm greenhouse cultures to complement imited available pesticides and to tackle emerging resistance. However, in response to high energy prices, greenhouse plant breeders have recently changed their greenhouse steering strategies, allowing more variation in temperature and humidity. The impact of these variations on biological control agents is poorly understood. Therefore, we constructed functional response models to demonstrate the impact of realistic climate variations on predation efficiency. First, two temperature regimes were compared at constant humidity (70%) and photoperiod (16L:8D): DIF0 (constant temperature) and DIF15 (variable temperature with day-night difference of 15°C). At mean temperatures of 25°C, DIF15 had a negative influence on the predation efficiency of P. persimilis and N. californicus, as compared to DIF0. At low mean temperatures of 15°C, however, DIF15 showed a higher predation efficiency for P. persimilis and N. californicus. For N. fallacis no difference was observed at both 15°C and 25°C. Secondly, two humidity regimes were compared, at a mean temperature of 25°C (DIFO) and constant photoperiod (16L:8D): RHCTE (constant 70% humidity) and RHALT (alternating 40% L:70%D humidity). For P. persimilis and N. fallacis RHCTE resulted in a higher predation efficiency than RHALT, for N. californicus this effect was opposite. This shows that N. californicus is more adapted to dry climates as compared to the other predatory mites. We conclude that variable greenhouse climates clearly affect predation efficiency of P. persimilis, N. californicus and N. fallacis. To obtain optimal control efficiency, the choice of predatory mites (including dose and application frequency

  19. Múltiple natural enemies do not improve two spotted spider mite and flower western thrips control in strawberry tunnels

    Directory of Open Access Journals (Sweden)

    Gemma Albendín

    2015-03-01

    Full Text Available Biological control techniques are commonly used in many horticultural crops in Spain, however the application of these techniques to Spanish strawberries are relatively recent. In this study the effectiveness of augmentative biological control techniques to control the two main strawberry (Fragaria xananassa Duchesne pest: the two-spotted spider mite (TSSM, Tetranychus urticae Koch (Acari: Tetranychidae, and the western flower thrips (WFT, Frankliniella occidentalis (Pergande (Thysanoptera: Thripidae, through releases of the predatory mites Phytoseiulus persimilis Athias-Henriot, Neoseiulus californicus (McGregor, Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae, and Orius laevigatus (Fieber (Heteroptera: Anthocoridae were tested. Two-year results on the performance of treatments using combinations of these biocontrol agents are presented. In both years, all treatments resulted in the reduction of TSSM numbers; but no treatment was better than the release of P. persimilis alone (P < 0.05. TSSM suppression varied among crop phases being greater early in the season. None of the treatments reduced significantly WFT numbers (P < 0.05, and the established economic injury level (EIL was surpassed from March to late April in both years. However, EIL was surpassed less times when treatment included O. laevigatus (2009: 20.7%; 2010: 22.7% of samples. No effect of A. swirskii was observed when this mite was released. Results corroborate that biological control techniques for TSSM and WFT are feasible for high-plastic tunnel strawberries. Under the conditions in our study no additive effects were observed, and there was not advantage in the release of multiple natural enemies.

  20. Ontogenetic shifts in intraguild predation on thrips by phytoseiid mites: the relevance of body size and diet specialization.

    Science.gov (United States)

    Walzer, A; Paulus, H F; Schausberger, P

    2004-12-01

    In greenhouse agroecosystems, a guild of spider mite predators may consist of the oligophagous predatory mite Phytoseiulus persimilis Athias-Henriot, the polyphagous predatory mite Neoseiulus californicus McGregor (both Acari: Phytoseiidae) and the primarily herbivorous but facultatively predatory western flower thrips Frankliniella occidentalis Pergande (Thysanoptera: Thripidae). Diet-specialization and the predator body size relative to prey are crucial factors in predation on F. occidentalis by P. persimilis and N. californicus. Here, it was tested whether the relevance of these factors changes during predator ontogeny. First, the predator (protonymphs and adult females of P. persimilis and N. californicus): prey (F. occidentalis first instars) body size ratios were measured. Second, the aggressiveness of P. persimilis and N. californicus towards F. occidentalis was assessed. Third, survival, development and oviposition of P. persimilis and N. californicus with F. occidentalis prey was determined. The body size ranking was P. persimilis females > N. californicus females > P. persimilis protonymphs > N. californicus protonymphs. Neoseiulus californicus females were the most aggressive predators, followed by highly aggressive N. californicus protonymphs and moderately aggressive P. persimilis protonymphs. Phytoseiulus persimilis females did not attack thrips. Frankliniella occidentalis larvae are an alternative prey for juvenile N. californicus and P. persimilis, enabling them to reach adulthood. Females of N. californicus but not P. persimilis sustained egg production with thrips prey. Within the guild studied here, N. californicus females are the most harmful predators for F. occidentalis larvae, followed by N. californicus and P. persimilis juveniles. Phytoseiulus persimilis females are harmless to F. occidentalis.

  1. Origins of asexuality in Bryobia mites (Acari: Tetranychidae)

    NARCIS (Netherlands)

    Ros, V.I.D.; Breeuwer, J.A.J.; Menken, S.B.J.

    2008-01-01

    Background Obligate asexual reproduction is rare in the animal kingdom. Generally, asexuals are considered evolutionary dead ends that are unable to radiate. The phytophagous mite genus Bryobia contains a large number of asexual species. In this study, we investigate the origin and evolution of

  2. Vectorial role of some dermanyssoid mites (Acari, Mesostigmata, Dermanyssoidea

    Directory of Open Access Journals (Sweden)

    Valiente Moro C.

    2005-06-01

    Full Text Available Among transmissible diseases, vectorial diseases represent a major problem for public health. In the group of acarina, while ticks are the most commonly implicated vectors, other arthropods and notably Dermanyssoidea are also involved in the transmission of pathogenic agents. Since the role of this superfamily is at present largely unknown, we have reviewed the vectorial role of these mites in the appearance, survival and propagation of pathogens. Various authors have shown that Dermanyssoidea are implicated in the transmission of both bacteria (Salmonella, Spirocheta, Rickettsia or Pasteurella and viruses (equine encephalitis viruses, West Nile virus, Fowl pox virus, the virus causing Newcastle disease and tick borne encephalitis viruses or hantaviruses. Finally, some authors have also shown their role in the transmission of some protozoa and filaria. As the vectorial character of such mites has been more clearly demonstrated (Dermanyssus gallinae, Ornithonyssus bacoti and Allodermanyssus sanguineus, it would be interesting to continue studies to better understand the role of this superfamily in the epidemiology of certain zoonoses.

  3. Six new species of ptyctimous mites (Acari: Oribatida) from Madagascar

    Czech Academy of Sciences Publication Activity Database

    Niedbala, W.; Starý, Josef

    2016-01-01

    Roč. 56, č. 4 (2016), s. 485-496 ISSN 0044-586X Institutional research plan: CEZ:AV0Z60660521 Institutional support: RVO:60077344 Keywords : Euphthiracaroidea * Madagascar * morphology * new species * ptyctimous mites * taxonomy Subject RIV: EG - Zoology Impact factor: 0.667, year: 2016

  4. Assessing hygienic behavior and attraction to Varroa mite (Acari ...

    African Journals Online (AJOL)

    user

    2011-02-07

    Feb 7, 2011 ... treatment and then the selected 5th instar larva were transferred to fundamental colonies with 10 to 12 ... Key words: Varroa mite, hygienic behavior (uncapping and .... into a container containing hot water and detergent.

  5. Biology of Dermacentor marginatus (Acari: Ixodidae under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Darvishi

    2014-02-01

    Full Text Available Objective: To investigate and survey the biology of Dermacentor marginatus (D. marginatus under laboratory conditions. Methods: In this investigation, D. marginatus adult ticks were collected from sheep in Semnan province. Then various developmental stages of D. marginatus including larvae, nymphs and adult males and females under laboratory condition were bred and their biology was scrutinized. Results: The requisite time to complete the life cycle of D. marginatus under controlled laboratory conditions for larvae (26 °C, 75% relative humidity and nymph (26 °C, 95% relative humidity moulting, was on average 92 d (range 75-104 d, including preoviposition and egg incubation (22.5 d, larvae incubation (20.5 d, nymphal stage (28 d along with male maturation (21 d. The index of conversion efficiency and the index of reproduction efficiency in females were 0.397 and 8.300, respectively. Conclusions: Although in this investigation, there was no meaningful correlation between preoviposition period and the weight of female ticks which were laid successfully. The significant linear relationship was fully observed between the weight of engorged female of D. marginatus and the number of eggs laid. The mean of preoviposition period from 5.4 d in autumn to 34.2 d in spring increased. The minimum weight of ticks with laying capacity was 69 mg and lighter ticks (21 mg either did not lay or if they did their eggs did not hatch.

  6. Relative humidity and activity patterns of Ixodes scapularis (Acari: Ixodidae)

    Science.gov (United States)

    Berger, K.A.; Ginsberg, Howard S.; Gonzalez, L.; Mather, T.N.

    2014-01-01

    Laboratory studies have shown clear relationships between relative humidity (RH) and the activity and survival of Ixodes scapularis Say (blacklegged tick). However, field studies have produced conflicting results. We examined this relationship using weekly tick count totals and hourly RH observations at three field sites, stratified by latitude, within the state of Rhode Island. Records of nymphal tick abundance were compared with several RH-related variables (e.g., RH at time of sampling and mean weekly daytime RH). In total, 825 nymphs were sampled in 2009, a year of greater precipitation, with a weighted average leaf litter RH recorded at time of sampling of 85.22%. Alternatively, 649 nymphs were collected in 2010, a year of relatively low precipitation, and a weighted average RH recorded at time of sampling was 75.51%. Negative binomial regression analysis of tick count totals identified cumulative hours <82% RH threshold as a significant factor observed in both years (2009: P = 0.0037; 2010: P < 0.0001). Mean weekly daytime RH did not significantly predict tick activity in either year. However, mean weekly daytime RH recorded with 1-wk lag before sample date was a significant variable (P = 0.0016) in 2010. These results suggest a lag effect between moisture availability and patterns of tick activity and abundance. Differences in the relative importance of each RH variable between years may have been due to abnormally wet summer conditions in 2009.

  7. Parasites and pathogens of ticks ( Rhipicephalus species Acari ...

    African Journals Online (AJOL)

    The interaction of ticks with its environment as well as its natural hosts predisposes it to acquiring pathogens that could pose animal and human health risks. Identifying these pathogens could alert dog owners and others to reassess the predisposing factors and ensure control. The aim of the study was to identify the species ...

  8. The ticks (Acari: Ixodida: Argasidae, Ixodidae) of Bolivia.

    Science.gov (United States)

    Mastropaolo, Mariano; Beltrán-Saavedra, L Fabián; Guglielmone, Alberto A

    2014-03-01

    The tick species reported in Bolivia are reviewed here as (1) endemic or established: Ornithodoros echimys, O. guaporensis, O. hasei, O. kohlsi, O. mimon, O. peropteryx, O. rostratus, Otobius megnini, Amblyomma auricularium, A. cajennense, A. calcaratum, A. coelebs, A. dubitatum, A. humerale, A. incisum, A. longirostre, A. naponense, A. nodosum, A. oblongoguttatum, A. ovale, A. parvitarsum, A. parvum, A. pecarium, A. pseudoconcolor, A. rotundatum, A. scalpturatum, A. tigrinum, A. triste, Dermacentor nitens, Haemaphysalis juxtakochi, H. leporispalustris, I. boliviensis, I. cooleyi, I. luciae, Rhipicephalus microplus, R. sanguineus, and (2) erroneously reported: Ornithodoros puertoricensis, O. talaje, O. turicata, Amblyomma americanum, A. maculatum, A. multipunctum, Ixodes ricinus, I. scapularis, Rhipicephalus annulatus. Many of these records are lacking locality and/or host, and some of them need new findings for confirmation. Some of the species recorded may represent a threat for human and animal health, therefore would be of great value to make a countrywide survey of ticks in order to update the information presented in this work. Copyright © 2013 Elsevier GmbH. All rights reserved.

  9. Oribatid mites from the Vohimana Reserve, Madagascar (Acari: Oribatida, II

    Directory of Open Access Journals (Sweden)

    Mahunka, S.

    2009-11-01

    Full Text Available Further studies on the oribatid species collected from the Vohimana Reserve (Madagascar are presented. Altogether 13 species are listed, of them two represent new genera (Rugocepheus gen. nov. and Madabelba gen. nov., furthermore seven species are new to science. The other six species were earlier mentioned from different regions of the island, they are however little known.

  10. Contribution to the Uropodina mites of Peru (Acari: Mesostigmata).

    Science.gov (United States)

    Kontschán, Jenő; Friedrich, Stefan

    2017-02-27

    Soil dwelling Uropodina mites were collected from a primary lowland rainforest in Amazonian Peru. The species found belong to three different families. A new diagnosis and the type genus of Tetrasejaspidae fam. nov. are given, and the family is recorded from Peru for the first time on the basis of Tetrasejaspis sellnicki Hirschmann, 1973. Two rotundabaloghid mites were collected (Rotundabaloghia (Circobaloghia) magna Hirschmann, 1992 and Rotundabaloghia (Circobaloghia) iquitosensis Hirschmann, 1992), both already reported from Peru. A new species (Origmatrachys peruensis sp. nov.) from the family Trachyuropodidae was collected in large numbers from soil, and is described on the basis of females, males, nymphs and larvae. This is the first description of the protonymphs and larvae of Origmatrachys. The new species differs from the previously described ones in the basis of sculptural pattern of dorsal, ventral, sternal shields and the length of the setae in the central part of the dorsal shield. A new key to the known adults and deutonymphs of Origmatrachys is given.

  11. Heavy metal sensitivity and bioconcentration in oribatid mites (Acari, Oribatida)

    Energy Technology Data Exchange (ETDEWEB)

    Skubala, Piotr, E-mail: piotr.skubala@us.edu.pl [Department of Ecology, University of Silesia, Bankowa 9, 40-007 Katowice (Poland); Zaleski, Tomasz [Department of Soil Science and Soil Protection, Agricultural University in Krakow, Mickiewicza 21, 31-120 Cracow (Poland)

    2012-01-01

    In this study we aimed to identify different reactions of oribatid species to heavy metal pollution and to measure concentrations of cadmium, zinc and copper in oribatid species sampled along a gradient. Oribatid mites were sampled seasonally during two years in five meadows located at different distances from the zinc smelter in the Olkusz District, southern Poland. Oribatids were shown to withstand critical metal concentration and established comparatively abundant and diverse communities. The highest abundance and species richness of oribatids were recorded in soils with moderate concentrations of heavy metals. Four different responses of oribatid species to heavy metal pollution were recognized. Heavy metals (Zn, Pb, Cd, Ni) and various physical (bulk density, field capacity, total porosity) and chemical (K{sub av}, P{sub av}, N, C, pH) factors were recognized as the structuring forces that influence the distribution of oribatid species. Analysis by atomic absorption spectrophotometry revealed large differences in metal body burdens among species. None of the species can be categorized as accumulators or non-accumulators of the heavy metals - the pattern depends on the metal. The process of bioconcentration of the toxic metal (regulated) and essential elements (accumulated) was generally different in the five oribatid species studied. - Highlights: Black-Right-Pointing-Pointer Responses of oribatid mites to metal contamination along a gradient in meadow soils were studied. Black-Right-Pointing-Pointer Small concentrations of heavy metals positively influenced the abundance of oribatid mites. Black-Right-Pointing-Pointer Four different responses of oribatid species to heavy metal pollution were recognised. Black-Right-Pointing-Pointer Bioaccumulation of the toxic metal and essential elements proceeded differently in oribatid species. Black-Right-Pointing-Pointer Five studied oribatid species were deconcentrators of cadmium.

  12. Widespread Rickettsia spp. Infections in Ticks (Acari: Ixodoidea) in Taiwan.

    Science.gov (United States)

    Kuo, Chi-Chien; Shu, Pei-Yun; Mu, Jung-Jung; Lee, Pei-Lung; Wu, Yin-Wen; Chung, Chien-Kung; Wang, Hsi-Chieh

    2015-09-01

    Ticks are second to mosquitoes as the most important disease vectors, and recent decades have witnessed the emergence of many novel tick-borne rickettsial diseases, but systematic surveys of ticks and tick-borne rickettsioses are generally lacking in Asia. We collected and identified ticks from small mammal hosts between 2006 and 2010 in different parts of Taiwan. Rickettsia spp. infections in ticks were identified by targeting ompB and gltA genes with nested polymerase chain reaction. In total, 2,732 ticks were collected from 1,356 small mammals. Rhipicephalus haemaphysaloides Supino (51.8% of total ticks), Haemaphysalis bandicota Hoogstraal & Kohls (28.0%), and Ixodes granulatus Supino (20.0%) were the most common tick species, and Rattus losea Swinhoe (44.7% of total ticks) and Bandicota indica Bechstein (39.9%) were the primary hosts. The average Rickettsia infective rate in 329 assayed ticks was 31.9% and eight Rickettsia spp. or closely related species were identified. This study shows that rickettsiae-infected ticks are widespread in Taiwan, with a high diversity of Rickettsia spp. circulating in the ticks. Because notifiable rickettsial diseases in Taiwan only include mite-borne scrub typhus and flea-borne murine typhus, more studies are warranted for a better understanding of the real extent of human risks to rickettsioses in Taiwan. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Ixodid Ticks (Acari, Ixodidae in Urban Landscapes. A review

    Directory of Open Access Journals (Sweden)

    Akimov I. А.

    2016-04-01

    Full Text Available This study presents the results of content analysis of published works on ixodid ticks in urban conditions in order to determine the species diversity, the vectors of research interests at various stages. Information about ticks in the cities up to the 1980s is incidental, to the point of exclusive, after this point there is targeted research in urban landscapes. There are 106 or 15 % of hard ticks of the world fauna registered in the urban territory, 26 species or 3.7 % being the most abundant. Of the urban hard tick species, 23 (88.5 % can attack humans, and 12 species are the most adapted to the urban landscape: Ixodes ricinus, I. persulcatus, Dermacentor reticulatus, D. marginatus, I. pavlovskyi, I. scapularis (dammini, Amblyomma cajennense, Haemaphysalis longicornis, I. hexagonus, Hyalomma marginatum, Am. americanum, and Rhipicephalus sanguineus. It was determined that the most likely causes of the growing number of publications on ixodids urban landscapes are: global accelerating urbanization, the development of recreational areas, the development of green tourism, the growth of the prestige of outdoor recreation, the creation of new, especially of the landscape parks and a tendency to preserve the native landscape in the cities, a significant increase in the density of populations of common species of hard ticks adapted to living in urban environment. The vectors of further work in urban landscapes will be directed to exact planning of monitoring studies of ixodids and associated tick-borne infections.

  14. A Proteomic Analysis of Sarcoptes scabiei (Acari: Sarcoptidae)

    Science.gov (United States)

    Morgan, Marjorie S.; Arlian, Larry G.; Rider, S. Dean; Grunwald, William C.; Cool, David R.

    2016-01-01

    The pruritic skin disease scabies is caused by the burrowing of the itch mite Sarcoptes scabiei (De Geer). It is difficult to diagnose this disease because its symptoms often resemble those of other skin diseases. No reliable blood or molecular diagnostic test is available. The aim of this project was to begin to characterize the scabies proteome to identify scabies mite proteins, including those that may be useful in the development of a diagnostic test or vaccine. Various scabies mite extracts were separated by two-dimensional electrophoresis, and 844 Coomassie Blue-stained protein spots were excised, subjected to trypsin digestion, and analyzed by Matrix Assisted Laser Desorption/Ionization Time-Of-Flight/Time-Of-Flight (MALDI-TOF/TOF) mass spectrometry (MS). Tryptic fragment sequences determined by MS were searched against the recently completed S. scabiei annotated genome, leading to the identification of >150 proteins. Only 10 proteins hit to previously identified scabies proteins including actin, tropomyosin, and several ABC transporters. Thirteen proteins had homology to dust mite allergens (members of groups 8, 10, 13, 17, 20, 25, and 28). Most other sequences showed some homology to proteins in other mites and ticks including homologs of calmodulin, calreticulin, lipocalin, and glutathione-S-transferase. These data will now allow the identification of the proteins to which scabies patients produce antibodies, including those that may be good candidates for inclusion in a diagnostic test and vaccine. PMID:26792847

  15. The ticks (Acari: Ixodida: Argasidae, Ixodidae) of Paraguay

    Science.gov (United States)

    2007-01-01

    20u209S, 60u209W Parque Defensores del Chaco 20u149S, 60u129W ALTO PARANÁ Ciudad del Este 25u329S, 54u379W BOQUERÓN Colonia Fernheim 22u149S, 59u509W...female, host unknown, Parque Defensores del Chaco, 5 December 1981, coll. J. A. Kochalka), RML 119014 (two males and one female, ex Catagonus wagneri...Moro, 22 June 2002, coll. M. Cunningham), RML 123661 (one female, ex Pa. onca, Parque Defensores del Chaco, 16 July 2003, coll. M. Cunningham), RML

  16. Assessing hygienic behavior and attraction to Varroa mite (Acari ...

    African Journals Online (AJOL)

    Three days later, the number of female Varroa in the capped cells were counted as attraction criteria for each treatment separately. ... The negative correlation between 2 major resistance traits (hygienic behavior and attraction traits) in the breeding stock deems that selection for resistance against Varroa mite and improved ...

  17. Resistance of the predacious mite, euseius kenyae (acari ...

    African Journals Online (AJOL)

    This study was carried out to assess whether the predacious phytoseiid mite, Euseius kenyae (Swirski and Ragusa), commonly found in major coffee growing regions in Kenya has developed resistance to Chlorpyrifos. Mite populations were collected from coffee farms harbouring E. kenyae and where Chlorpyrifos or other ...

  18. Listado de oribátidos (Acari, Oribatida de Túnez

    Directory of Open Access Journals (Sweden)

    Subías, L. S.

    2015-12-01

    Full Text Available The oribatid mites of several Tunisian soil samples were studied. 113 species were obtained, 95 of which are recorded for the first time from Tunisia. A systematic check-list with the 136 species known up to now is included, and their geographical distribution is given. Most of them, 77 (56%, have a typical Mediterranean distribution and 16 are recorded for the first time from North Africa.Se han estudiado los ácaros oribátidos de una serie de muestras de suelo de Túnez y se han identificado 113 especies, 95 de las cuales se citan por primera vez en Túnez. Se ha elaborado un listado sistemático en el que se incluyen las 136 especies conocidas hasta el momento y su distribución geográfica. La mayoría, 77 (56 %, presentan características típicamente mediterráneas, y 16 se citan por primera vez en el norte de África.

  19. A supplementary description of Brevipalpus californicus (Acari: Trombidiformes: Tenuipalpidae

    Directory of Open Access Journals (Sweden)

    Mohammad Raissi Ardali

    2015-10-01

    Full Text Available The false spider mite Brevipalpus californicus from the family Tenuipalpidae was collected from Caucasian alnus, White willow, Persian raspberry and a wild Chrysanthemum bush in Mazandaran province. This species is reported as a new record to the false spider mites-fauna of Iran here. Reviewing literatures revealed that it was briefly described in the original paper without any measures. So, a completed description is presented based on the Iranian specimens and different body segments are drawn for B. californicus. In addition, the above plants are new host records for B. californicus.

  20. Can Euseius alatus DeLeon (Acari: Phytoseiidae) prey on Aceria guerreronis Keifer (Acari: Eriophyidae) in coconut palm?; Pode Euseius alatus DeLeon (Acari: Phytoseiidae) predar Aceria guerreronis Keifer (Acari: Eriophyidae) em coqueiro?

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Jose W. da S.; Domingos, Cleiton A.; Gondim Junior, Manoel G.C. [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Dept. de Agronomia. Area de Fitossanidade]. E-mail: mguedes@depa.ufrpe.br; Moraes, Gilberto J. de [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. de Entomologia, Fitopatologia e Zoologia Agricola]. E-mail: gjmoraes@carpa.ciagri.usp.br

    2009-01-15

    Mites of the genus Euseius are generally considered specialist as pollen feeders. Euseius alatus DeLeon is one of the six species of phytoseiid mites most commonly found on coconut plants in northeast Brazil associated with Aceria guerreronis Keifer. Although the morphology of E. alatus does not favor the exploitation of the meristematic area of the fruit inhabited by A. guerreronis, the predator may have some role in the control of this eriophyid during the dispersion process. The objective of this work was to evaluate the development and reproduction of E. alatus on the following diets: A. guerreronis, Ricinus communis pollen (Euphorbiaceae), and Tetranychus urticae Koch (Tetranychidae) + R. communis pollen + honey solution 10%. Euseius alatus developed slightly faster and had slightly higher oviposition rate when feeding on the diet composed of T. urticae + pollen + honey. However, life table parameters were very similar on all diets, suggesting that E. alatus may contribute in reducing the population of A. guerreronis in the field. (author)

  1. The dual nature of trehalose in citrus canker disease: a virulence factor for Xanthomonas citri subsp. citri and a trigger for plant defence responses

    KAUST Repository

    Piazza, A.; Zimaro, T.; Garavaglia, B. S.; Ficarra, F. A.; Thomas, L.; Marondedze, C.; Feil, R.; Lunn, J. E.; Gehring, Christoph A; Ottado, J.; Gottig, N.

    2015-01-01

    and proteomic analyses of infected leaves showed that infection with XccΔotsA triggered only weak defence responses in the plant compared with infection with Xcc, and had less impact on the host plant's metabolism than the wild-type strain. These results

  2. Inhibition of Xanthomonas citri subsp. citri, causal agent of citrus canker, by a strain of Zymomonas mobilis mobilis isolated from sugarcane

    OpenAIRE

    Romero, María E.; Ramallo, C. Jacqueline; Ploper, L. Daniel

    2008-01-01

    Zymomonas mobilis mobilis (Zm) produce factores antimicrobianos que actúan sobre un amplio espectro de microorganismos patógenos para el hombre, animales y plantas. Un problema importante a resolver en los tratamientos con antimicrobianos, es el desarrollo de resistencia a compuestos empleados actualmente, no siendo las bacterias fitopatógenas una excepción. En el presente trabajo se realizaron ensayos de antagonismo con células (pruebas de estrías cruzadas) y sobrenadantes concentrados (Sc) ...

  3. Plant species modifies the functional response of Phytoseiulus persimilis (Acari: Phytoseiidae) to Tetranychus urticae (Acari: Tetranychidae): implications for biological control.

    Science.gov (United States)

    Skirvin, D J; Fenlon, J S

    2001-02-01

    The functional response of the predatory mite Phytoseiulus persimilis Athias-Henriot to eggs of its prey, the spider mite Tetranychus urticae Koch was examined on three plant species. Experiments were done to determine whether differences in the functional response on the three plant species were due to the morphological features of the crop directly on the predator or through an effect of the plant species on the prey. The results show that crop morphology is the only factor influencing the predatory ability of P. persimilis on the three plant species. Fewer eggs were eaten on Ceanothus thyrsiflorus var. 'Autumnal Blue', the plant species with hairy leaves, and greater numbers of prey consumed on Choisya ternata, a species with smooth leaves. However, similarly few eggs were eaten on the smooth, but waxy leaved Euonymus japonicus as on Ceanothus thyrsiflorus, demonstrating that morphological characters of leaves other than the possession of hairs and trichomes may affect the rates of predation. The implications of these results for the tritrophic interactions between plant, predator and prey, and the development of suitable biological control strategies are discussed.

  4. Alternating temperatures affect life table parameters of Phytoseiulus persimilis, Neoseiulus californicus (Acari: Phytoseiidae) and their prey Tetranychus urticae (Acari: Tetranychidae).

    Science.gov (United States)

    Vangansbeke, Dominiek; De Schrijver, Lien; Spranghers, Thomas; Audenaert, Joachim; Verhoeven, Ruth; Nguyen, Duc Tung; Gobin, Bruno; Tirry, Luc; De Clercq, Patrick

    2013-11-01

    Increasing energy costs force glasshouse growers to switch to energy saving strategies. In the temperature integration approach, considerable daily temperature variations are allowed, which not only have an important influence on plant growth but also on the development rate of arthropods in the crop. Therefore, we examined the influence of two constant temperature regimes (15 °C/15 °C and 20 °C/20 °C) and one alternating temperature regime (20 °C/5 °C, with an average of 15 °C) on life table parameters of Phytoseiulus persimilis and Neoseiulus californicus and their target pest, the two-spotted spider mite Tetranychus urticae at a 16:8 (L:D) h photoperiod and 65 ± 5 % RH. For females of both predatory mites the alternating temperature regime resulted in a 25-30 % shorter developmental time as compared to the corresponding mean constant temperature regime of 15 °C/15 °C. The immature development of female spider mites was prolonged for 7 days at 15 °C/15 °C as compared to 20 °C/5 °C. With a daytime temperature of 20 °C, no differences in lifetime fecundity were observed between a nighttime temperature of 20 and 5 °C for P. persimilis and T. urticae. The two latter species did show a higher lifetime fecundity at 20 °C/5 °C than at 15 °C/15 °C, and their daily fecundity at the alternating regime was about 30 % higher than at the corresponding mean constant temperature. P. persimilis and T. urticae showed no differences in sex ratio between the three temperature regimes, whereas the proportion of N. californicus females at 15 °C/15 °C (54.2 %) was significantly lower than that at 20 °C/5 °C (69.4 %) and 20 °C/20 °C (67.2 %). Intrinsic rates of increase were higher at the alternating temperature than at the corresponding mean constant temperature for both pest and predators. Our results indicate that thermal responses of the studied phytoseiid predators to alternating temperature regimes used in energy saving strategies in glasshouse crops may have consequences for their efficacy in biological control programs.

  5. Olfactory response of Phytoseiulus persimilis (Acari: Phytoseiidae) to untreated and Beauveria bassiana-treated Tetranychus urticae (Acari: Tetranychidae).

    Science.gov (United States)

    Seiedy, Marjan; Saboori, Alireza; Zahedi-Golpayegani, Azadeh

    2013-06-01

    Determination of attraction and avoidance behavior of predators is important in concomitant use of multiple natural enemies to control a pest. The olfactory response of the predatory mite Phytoseiulus persimilis was studied to odors related to Tetranychus urticae adults infected by Beauveria bassiana DEBI008 in 0, 24, 48 and 72 h intervals, both in absence and in presence of plants. In plant-present experiments, P. persimilis attraction was neither towards adults of T. urticae infected by 0.02 % Tween 80 (as control), nor to the ones infected by B. bassiana for 0 or 24 h, whereas significant attraction towards the control was observed when tested against T. urticae infected by B. bassiana for 48 or 72 h. In absence of plants, P. persimilis displayed significant avoidance of T. urticae infected by B. bassiana for 48 or 72 h, when their alternative option was 0.02 % Tween 80-infected T. urticae adults. These results indicate that P. persimilis can recognize the presence of B. bassiana and that the predator avoids the fungus. This suggests that the two natural enemy species can be used together in biological control programmes.

  6. Effects of azadirachtin on Tetranychus urticae (Acari: Tetranychidae) and its compatibility with predatory mites (Acari: Phytoseiidae) on strawberry.

    Science.gov (United States)

    Bernardi, Daniel; Botton, Marcos; da Cunha, Uemerson Silva; Bernardi, Oderlei; Malausa, Thibaut; Garcia, Mauro Silveira; Nava, Dori Edson

    2013-01-01

    The spider mite, Tetranychus urticae, is the major strawberry pest in Brazil. The main strategies for its control comprise synthetic acaricides and predatory mites. The recent register of a commercial formula of azadirachtin (Azamax(®) 12 g L(-1) ) can be viable for control of T. urticae. In this work, the effects of azadirachtin on T. urticae and its compatibility with predatory mites Neoseiulus californicus and Phytoseiulus macropilis in the strawberry crop were evaluated. Azadirachtin was efficient against T. urticae, with a mortality rate similar to that of abamectin. In addition, the azadirachtin showed lower biological persistence (7 days) than abamectin (21 days). Azadirachtin did not cause significant mortality of adult predatory mites (N. californicus and P. macropilis), but it did reduce fecundity by 50%. However, egg viability of the azadirachtin treatments was similar to that of the control (>80% viability). The use of azadirachtin and predatory mites is a valuable tool for controlling T. urticae in strawberry crop. Azadirachtin provided effective control of T. urticae and is compatible with the predatory mites N. californicus and P. macropilis. It is an excellent tool to be incorporated into integrated pest management for strawberry crop in Brazil. Copyright © 2012 Society of Chemical Industry.

  7. Can Euseius alatus DeLeon (Acari: Phytoseiidae) prey on Aceria guerreronis Keifer (Acari: Eriophyidae) in coconut palm?

    International Nuclear Information System (INIS)

    Melo, Jose W. da S.; Domingos, Cleiton A.; Gondim Junior, Manoel G.C.; Moraes, Gilberto J. de

    2009-01-01

    Mites of the genus Euseius are generally considered specialist as pollen feeders. Euseius alatus DeLeon is one of the six species of phytoseiid mites most commonly found on coconut plants in northeast Brazil associated with Aceria guerreronis Keifer. Although the morphology of E. alatus does not favor the exploitation of the meristematic area of the fruit inhabited by A. guerreronis, the predator may have some role in the control of this eriophyid during the dispersion process. The objective of this work was to evaluate the development and reproduction of E. alatus on the following diets: A. guerreronis, Ricinus communis pollen (Euphorbiaceae), and Tetranychus urticae Koch (Tetranychidae) + R. communis pollen + honey solution 10%. Euseius alatus developed slightly faster and had slightly higher oviposition rate when feeding on the diet composed of T. urticae + pollen + honey. However, life table parameters were very similar on all diets, suggesting that E. alatus may contribute in reducing the population of A. guerreronis in the field. (author)

  8. Ocorrência de Brevipalpus phoenicis (Geijskes (Acari, Tenuipalpidae, Tetranychus urticae (Koch (Acari, Tetranychidae e Polyphagotarsonemus latus (Banks (Acari, Tarsonemidae sobre folhas de Ipomoea cairica (Linnaeus Sweet (Solanales, Convolvulaceae Occurrence of Brevipalpus phoenicis (Geijskes (Acari, Tenuipalpidae, Tetranychus urticae (Koch (Acari, Tetranychidae and Polyphagotarsonemus latus (Banks (Acari, Tarsonemidae on leaves of I. cairica (Linnaeus Sweet (Solanales, Convolvulaceae

    Directory of Open Access Journals (Sweden)

    Ozana M. de A. Maia

    2006-09-01

    Full Text Available A ocorrência de três espécies acarinas fitófagas é relatada pela primeira vez sobre folhas de Ipomoea cairica. As espécies Brevipalpus phoenicis (Geijskes, Tetranychus urticae (Koch e Polyphagotarsonemus latus (Banks, foram coletadas sobre folhas de I. cairica nas imediações da Universidade Federal do Paraná, Curitiba, Paraná, Brasil, em 20 de janeiro de 2005.The first occurrence of three phytophagus mites on Ipomoea cairica, is reported. The species Brevipalpus phoenicis (Geijskes, Tetranychus urticae (Koch and Polyphagotarsonemus latus (Banks were caught on leaves of I. cairica, around Universidade Federal do Paraná, Curitiba, Paraná, Brazil, in January 20th, 2005.

  9. Suspension of Egg Hatching Caused by High Humidity and Submergence in Spider Mites.

    Science.gov (United States)

    Ubara, Masashi; Osakabe, Masahiro

    2015-08-01

    We tested the effects of high humidity and submergence on egg hatching of spider mites. In both the high humidity and submergence treatments, many Tetranychus and Panonychus eggs did not hatch until after the hatching peak of the lower humidity or unsubmerged controls. However, after humidity decreased or water was drained, many eggs hatched within 1-3 h. This was observed regardless of when high humidity or submergence treatments were implemented: either immediately after oviposition or immediately before hatching was due. Normal eyespot formation was observed in most eggs in the high humidity and submergence treatments, which indicates that spider mite embryos develop even when eggs are underwater. Therefore, delays in hatching are not caused by delayed embryonic development. A delay in hatching was always observed in Panonychus citri (McGregor) but was more variable in Tetranychus urticae Koch and Tetranychus kanzawai Kishida. The high humidity and submergence treatments affected but did not suppress larval development in these species. In contrast, many Oligonychus eggs died following the high humidity treatments. In Tetranychus and Panonychus spider mites, suspension of egg hatching may mitigate the adverse effects of rainfall. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Differential effects of exposure to ambient vanilla and citris aromas on mood, arousal and food choice

    NARCIS (Netherlands)

    Wijk, de R.A.; Zijlstra, S.

    2012-01-01

    Background Aromas have been associated with physiological, psychological affective and behavioral effects. We tested whether effects of low-level exposure to two ambient food-related aromas (citrus and vanilla) could be measured with small numbers of subjects, low-cost physiological sensors and

  11. Putative sex pheromone of the Asian citrus psyllid, Diaphorina citri, breaks down into an attractant.

    Science.gov (United States)

    Zanardi, Odimar Z; Volpe, Haroldo X L; Favaris, Arodi P; Silva, Weliton D; Luvizotto, Rejane A G; Magnani, Rodrigo F; Esperança, Victoria; Delfino, Jennifer Y; de Freitas, Renato; Miranda, Marcelo P; Parra, José Roberto P; Bento, José Mauricio S; Leal, Walter S

    2018-01-11

    Under laboratory conditions, mating activity in Asian citrus psyllid (ACP) started 4 days after emergence, peaked at day 7, and showed a clear window of activity starting 8 h into the photophase and extending through the first hour of the scotophase. We confirmed that ACP males are attracted to emanations from conspecific females. Traps loaded with a candidate compound enriched with female extract, lignoceryl acetate (24Ac), at various doses were active only after being deployed for several weeks in the field, suggesting that a degradation product, not the test compound, was the active ingredient(s). Lignocerol, a possible product of 24Ac degradation, was not active, whereas acetic acid, another possible degradation product, was found in the airborne volatile collections from lures matured under field conditions and detected in higher amounts in volatiles collected from females at the peak of mating activity than in male samples. Acetic acid elicited dose-dependent electroantennographic responses and attracted ACP males, but not females, in Y-type and 4-way olfactometers. Field tests showed that acetic acid-baited traps captured significantly more males than control traps. Surprisingly, captures of females in acetic acid-baited traps were also higher than in control traps, possibly because of physical stimuli emitted by captured males.

  12. H NMR analyses of Citrus macrophylla subjected to Asian citrus psyllid (Diaphorina citri Kuwayama) feeding

    Science.gov (United States)

    The Asian citrus psyllid (ACP) is a phloem feeding insect that can host and transmit the bacterium Candidatus Liberibacter asiaticus (CLas), which is the putative causative agent of the economically important citrus disease, Huanglongbing (HLB). ACP are widespread in Florida, and are spreading in Ca...

  13. 〈研究ノート〉文献解題 Warren J McGregor: Liabilities─The Neglected Element : A Conceptual Analysis of the Financial Reporting of Liabilities(AASB Occasional Paper No. 1)

    OpenAIRE

    赤塚, 尚之

    2015-01-01

    The aim of this paper is to introduce the proposals of AASB Occasional Paper No. 1 in the Japanese language. This Occasional Paper focuses on the accounting for liabilities( definition, recognition, measurement, and disclosure issues) neglected until recently. As far as I know, there are no materials in Japan that focus on the Occasional Paper itself except ASBJ( 2013) prepared for the ASAF meeting held on December 2013.  Occasional Paper No. 1 leads the proposals of accounting for liabiliti...

  14. 76 FR 4859 - Availability of an Environmental Assessment and Finding of No Significant Impact for a Biological...

    Science.gov (United States)

    2011-01-27

    ... (Diaphorina citri Kuwayama). The environmental assessment considers the effects of, and alternatives to, the...) for the Biological Control of Asian Citrus Psyllid (Diaphorina citri Kuwayama) in the Continental...

  15. Nuevas citas de ácaros oribátidos (Acari: Oribatida para la Argentina New records of oribatids (Acari: Oribatida for Argentina

    Directory of Open Access Journals (Sweden)

    Ana Salazar Martínez

    2006-12-01

    Full Text Available En la presente nota se citan, por primera vez para la Argentina , cuatro especies de ácaros oribátidos: Epilohmannia pallida americana Balogh & Mahunka, 1981, Protoribates (Triangius praeoccupatus (Pérez-Iñigo & Baggio, 1980, Scheloribates curvialatus Hammer, 1961 y Galumna innexa Pérez-Iñigo & Baggio, 1986. Los ejemplares fueron hallados en muestras de suelo recolectadas en La Plata , Provincia de Buenos Aires (34º 54'S, 57º 55´ W, en ambientes sometidos a intervención antrópica: bosques urbanos, huertas orgánicas y pastizales.Four species of oribatid mites are recorded from Argentina for the first time: Epilohmannia pallida americana Balogh & Mahunka, 1981, Protoribates (Triangius praeoccupatus (Pérez-Iñigo & Baggio, 1980, Scheloribates curvialatus Hammer, 1961 and Galumna innexa Pérez-Iñigo & Baggio, 1986. The specimens were collected in soil samples in La Plata , Buenos Aires Province (34º 54' S, 57º 55´ W in sites exposed to different degrees of human intervention: urban forest, organic orchards and pastures.

  16. The influence of sublethal deposits of agricultural mineral oil on the functional and numerical responses of Phytoseiulus persimilis (Acari: Phytoseiidae) to its prey, Tetranychus urticae (Acari: Tetranychidae).

    Science.gov (United States)

    Xue, Yingen; Meats, Alan; Beattie, G Andrew C; Spooner-Hart, Robert; Herron, Grant A

    2009-08-01

    Occasional pesticide application in integrated pest management to at least part of a crop requires that any biological control agents must re-invade previously sprayed areas in order that resurgent pests can be constrained. The ability of the phytoseiid predatory mite Phytoseiulus persimilis to feed on adult two-spotted spider mite (TSSM) Tetranychus urticae on excised leaf discs in both control conditions and in a treatment with a sub lethal residue of agricultural mineral oil (AMO) was assessed. The predator exhibited a Type II functional response with the asymptote significantly higher in the AMO conditions due to the fact that the prey grew slower and reached a smaller size in this treatment. In terms of prey volume eaten, the satiation level of the predator was unchanged by the AMO deposits. The numbers of eggs produced by adult P. persimilis females at densities of 4, 8 and 16 TSSM adult females/disc in the control were significantly higher than those in the AMO treatment, but were similar for the higher density levels, 32 and 64 prey per disc. Thus the functional response in terms of volume of prey eaten explained the numerical response in terms of predator eggs produced. The presence of AMO deposits when the prey were at high density had no effect on predator efficiency (volume eaten) but resulted in a lower intake than that in control conditions when there was a greater distance between prey.

  17. The effect of indoxacarb and five other insecticides on Phytoseiulus persimilis (Acari: Phytoseiidae), Amblyseius fallacis (Acari: Phytoseiidae) and nymphs of Orius insidiosus (Hemiptera: Anthocoridae).

    Science.gov (United States)

    Bostanian, Noubar J; Akalach, Mohammed

    2006-04-01

    A laboratory study assessed the contact toxicity of indoxacarb, abamectin, endosulfan, insecticidal soap, S-kinoprene and dimethoate to Amblyseius fallacis (Garman), Phytoseiulus persimilis Athias-Henriot and nymphs of Orius insidiosus (Say). Amblyseius fallacis is a predacious phytoseiid mite and an integral part of integrated pest management (IPM) programmes in North American apple orchards. The other two beneficials are widely used in greenhouses to manage various arthropod pests infesting vegetable and ornamental crops. Indoxacarb is a slow-acting insecticide, so toxicity data were recorded 7 days post-treatment when the data had stabilised. It showed no toxicity to O. insidiosus nymphs or to A. fallacis or P. persimilis adults. The LC50 values for O. insidiosus nymphs and P. persimilis could not be estimated with their associated confidence limits, because the g values were greater than 0.5 and under such circumstances the lethal concentration would lie outside the limits. The LC50 for A. fallacis was 7.6x the label rate. The fecundity of P. persimilis was reduced by 26.7%. The eclosion of treated eggs from both species of beneficial mites was not affected adversely. Among the other pest control products, S-kinoprene and endosulfan affected adversely at least one species of the predators, whereas dimethoate, abamectin and insecticidal soap were very toxic to all three beneficials. Indoxacarb should be evaluated as a pest control product in IPM programmes. Copyright (c) 2006 Crown in the right of Canada.

  18. The effect of chrysanthemum leaf trichome density and prey spatial distribution on predation of Tetranychus urticae (Acari: Tetranychidae) by Phytoseiulus persimilis (Acari: Phytoseiidae).

    Science.gov (United States)

    Skirvin, D J; Stavrinides, M C; Skirvin, D J

    2003-08-01

    The effect of plant architecture, in terms of leaf hairiness, and prey spatial arrangement, on predation rate of eggs of the spider mite, Tetranychus urticae Koch, by the predatory mite Phytoseiulus persimilis Athias-Henriot was examined on cut stems of chrysanthemums. Three levels of leaf hairiness (trichome density) were obtained using two different chrysanthemum cultivars and two ages within one of the cultivars. The number of prey consumed by P. persimilis was inversely related to trichome density. At low prey densities (less than ten eggs per stem), prey consumption did not differ in a biologically meaningful way between treatments. The effect of prey spatial arrangement on the predation rate of P. persimilis was also examined. Predation rates were higher in prey patches on leaves adjacent to the release point of P. persimilis, but significantly greater numbers of prey were consumed in higher density prey patches compared to low density patches. The predators exhibited non-random searching behaviour, spending more time on leaves closest to the release point. The implications of these findings for biological control and predator-prey dynamics are discussed.

  19. Ritmo de queda de Rhipicephalus sanguineus (Acari: Ixodidae de cães artificialmente infestados Drop off rhythm of Rhipicephalus sanguineus (Acari: Ixodidae of artificially infested dogs

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    Gustavo F. Paz

    2008-09-01

    Full Text Available O ritmo de queda de Rhipicephalus sanguineus (Latreille foi avaliado para duas populações do Brasil; uma de Monte Negro, Estado de Rondônia, e outra de Belo Horizonte, Estado de Minas Gerais. Infestações artificiais com carrapatos das duas populações foram realizadas em cães domésticos mantidos em laboratório, sob o regime de luz: escotofase de 12:12 h. O padrão de queda de larvas ingurgitadas do hospedeiro se caracterizou pelo desprendimento de quantidades semelhantes de carrapatos em períodos de luz e de escotofase ou com um predomínio de queda durante o período de luz. No caso de ninfas e fêmeas ingurgitadas, a maioria dos carrapatos se desprendeu dos cães durante o período de escotofase, em todos os casos observados. Desta forma, é possível que em condições naturais, a maioria das ninfas e fêmeas adultas de R. sanguineus tendem a se desprender dos cães durante o período noturno, ao passo que larvas ingurgitadas se desprendem em proporções maiores durante o período diurno. Com base nestes dados, sugere-se que os locais onde os cães freqüentam durante a noite (onde possivelmente estará a maior parte da população de vida livre de R. sanguineus sejam priorizados com os tratamentos ambientais utilizando-se produtos carrapaticidas.The present study evaluated the drop-off rhythm of Rhipicephalus sanguineus (Latreille ticks from two populations from Brazil, one from Monte Negro, state of Rondônia, and another from Belo Horizonte, state of Minas Gerais. Artificial infestations with ticks were performed on dogs in the laboratory, held in a light: scotophase regimen of 12:12 h. Larval drop-off rhythm was characterized by similar number of engorged larvae detaching during both periods of light and scotophase, or by a larger number of larvae detaching during the light period. In contrast, most of the engorged nymphs and females detached from dogs during the scotophase period. These results indicate that under natural conditions, most of R. sanguineus engorged nymphs and females detach from dogs during the night period, whereas engorged larvae detach in higher proportions during daytime. Based on these data, tick control measures, encompassing environmental treatments with acaricide, should be indicated. The control measures are especially indicated in places where dogs spend or visit during the night period, since these places possibly harbor most of the free-living stages of R. sanguineus.

  20. A gallery of the key characters to ease identification of Dermanyssus gallinae (Acari: Gamasida: Dermanyssidae and allow differentiation from Ornithonyssus sylviarum (Acari: Gamasida: Macronyssidae

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    Di Palma Antonella

    2012-05-01

    Full Text Available Abstract Background Dermanyssus gallinae (poultry red mite is a major threat for the poultry industry and is of significant interest for public health. Identification of D. gallinae can be difficult for scientists not familiar with mite morphology and terminology especially when trying to use identification keys. Moreover, this species may easily be confused with another dermanyssoid mite, Ornithonyssus sylviarum (northern fowl mite, which often shares the same hosts and environment. Methods Specimens of D. gallinae were collected at poultry farms in the Puglia and performed for light and scanning electron microscopy observations, identification and micrographs. Moreover specimens of O. sylviarum were collected separately macerated and mounted on slides for light microscopy observations, identification and pictures. Results The micrographs used in this study, based on LM and SEM observations, highlight the following important identifying characters of D. gallinae: the prominent shoulders of the dorsal shield and the jagged edges of the shield reticulations, the position of setae j1, s1 and the epigynal pores, and the presence on tibia IV pl of one seta. Additional micrographs highlighting the shape of the dorsal (abruptly narrowed posteriorly and epigynal (narrowly rounded posteriorly shields and the chelicera (elongate, with distinct digits of O. sylviarum enable its differentiation from D.gallinae. Conclusion The photographic support provided here (both LM and SEM pictures can be considered a practical tool for scientists who are not well acquainted with the morphology of D.gallinae, and who are involved with classical and molecular systematics, veterinary and human health aspects of poultry red mites.

  1. Suscetibilidade de Oligonychus yothersi (Acari: Tetranychidae ao fungo Beauveria bassiana Susceptibility of Oligonychus yothersi (Acari: Tetranychidae to the fungus Beauveria bassiana

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    Renato Cassol de Oliveira

    2002-03-01

    Full Text Available A cultura da erva-mate (Ilex paraguariensis é uma importante atividade econômica no Sul do Brasil. Com o aumento de consumo nos anos oitenta, cresceram também as áreas de monocultura, gerando condições favoráveis para o aumento populacional de insetos e ácaros fitófagos, entre eles o ácaro vermelho Oligonychus yothersi. Este estudo avaliou a suscetibilidade do ácaro vermelho O. yothersi a vários isolados do fungo Beauveria bassiana. O experimento foi conduzido em Cascavel, PR. Discos foliares de erva-mate (2,2 cm² foram previamente infestados com 20 fêmeas adultas. Alíquotas de 1 mL de cada suspensão de conídios dos diferentes isolados de B. bassiana, ajustadas na concentração de 1,0x10(8 conídios mL-1 foram pulverizadas, separadamente, sobre um conjunto de 5 discos. Os discos foliares foram mantidos flutuando em água destilada, em caixas plásticas (3 cm de diâmetro, sob condições controladas. Diariamente, os ácaros mortos foram transferidos para câmara úmida, para confirmação de mortalidade causada pelo fungo. A mortalidade total variou entre 77 e 98% (6 dias após a aplicação, não permitindo diferenciar os isolados quanto à virulência (P>0,05. Já a mortalidade confirmada variou entre 19 e 75%, permitindo diferenciá-los (PThe Paraguay tea (Ilex paraguariensis crop is an important economical activity in Southern Brazil. With the increase of tea consumption in the 80s, the number of monoculture crops also increased, creating favorable conditions for the development of phytophagous insect and mite populations, such as the red mite Oligonychus yothersi. The objective of this study was to evaluate the susceptibility of the red mite O. yothersi to the several strains of the Beauveria bassiana fungus. The experiments were carried out in Cascavel, PR, Brazil. Leaf disks of Paraguay tea (2.2 cm² were previously infested with 20 adult females. Five disks were inoculated with 1 mL of each conidial suspension of B. bassiana strains (1x10(8 conidia per mL. Disks were kept afloat on distilled water in plastic boxes (3 cm diameter, under controlled conditions. Dead mites were transferred to a humid chamber on a daily basis to confirm the mortalities rate by the fungus. All the strains were pathogenic, with total mortality varying from 77 to 98%, 6 days after application. It was not possible to differentiate virulence levels between strains (P<0.05 by total mortality. However, confirmed mortality varied from 19 to 75%, 8 days after application, allowing for a differentiation in virulence levels between strains (P<0.05. This study concluded that the O. yothersi red mite is susceptible, at different levels, to B. bassiana tested strains.

  2. Environmentally associated ticks (Acari: Ixodidae in Campo Grande, Mato Grosso do Sul, Brazil Carrapatos (Acari: Ixodidae associados com o ambiente em Campo Grande, Mato Grosso do Sul, Brasil

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    Marcos Valério Garcia

    2013-03-01

    Full Text Available Herein, we report tick species found on wild and domestic animals and in the environment during a one-year sampling period at the Brazilian Farming Research Company beef cattle unit (Embrapa Beef Cattle, which is located within the urban area of Campo Grande, Mato Grosso do Sul, Brazil. From 55 wild hosts including six different species (Nasua nasua, Cebus spp., Cerdocyon thous, Myrmecophaga tridactyla, Tamandua tetradactyla and Dasyprocta aguti, 323 ticks were collected. Amblyomma ovale ticks were found solely on coatis, and Amblyomma nodosum was identified solely on anteaters. No ticks were found on capuchin monkeys. However, Amblyomma cajennense was found on all parasitized host species with the exception of capuchin monkeys. Giant anteaters displayed the highest infestation abundance, with a mean of 53 ticks∕animal. Environmental sampling yielded 166 adult A. cajennense ticks. The tick species found on domestic animals (Rhipicephalus (Boophilus microplus, R. sanguineus, Dermacentor nitens and A. cajennense were those typically found on these hosts in Brazil. The most prevalent tick species, A. cajennense, was found on both wild and domestic animals and was also prevalent in the environment. Thus, this tick species is the primary vector that allows pathogens to bridge wild and domestic animals in the Cerrado.Neste trabalho são descritas as espécies de carrapatos de animais selvagens e domésticos e do ambiente coletados por um ano na EMBRAPA Gado de Corte localizado na área urbana de Campo Grande, Mato Grosso do Sul, Brasil. Dos 55 hospedeiros selvagens de seis espécies diferentes (Nasua nasua, Cebus spp., Cerdocyon thous, Myrmecophaga tridactyla, Tamandua tetradactyla e Dasyprocta aguti foram coletados 323 carrapatos. Amblyomma ovale foi encontrado apenas em quatis e Amblyomma nodosum apenas sobre tamanduás. Nenhum carrapato foi encontrado sobre macacos-prego. Por outro lado, Amblyomma cajennense foi encontrado em todos os hospedeiros com exceção dos macacos-pregos. A maior abundancia de infestação foi aquela em tamanduás-bandeira com média de 53 carrapatos∕animal. No ambiente foram capturados 166 carrapatos, todos da espécie A. cajennense. As espécies de carrapatos em animais domésticos (Rhipicephalus (Boophilus microplus, Rhipicephalus sanguineus, Dermacentor nitens e A. cajennense foram aquelas características nestes hospedeiros no Brasil. De forma geral a espécie de carrapato A. cajennense foi a mais prevalente sendo encontrada em animais domésticos e selvagens bem como no ambiente. Portanto, esta é a principal espécie de vetor a estabelecer uma ponte para bioagentes patogênicos entre animais domésticos e selvagens.

  3. Selection of Entomopathogenic Fungi to Control Varroa destructor (Acari: Varroidae Selección de Hongos Entomopatógenos para el Control de Varroa destructor (Acari: Varroidae

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    Marta Rodríguez

    2009-12-01

    Full Text Available The aim of this work was select entomopathogenic fungi tolerant to temperatures inside the brood area of honey bees (Apis mellifera for to control Varroa destructor. For this purpose, 50 Beauveria bassiana (Balsamo Vuillemin and 48 Metarhizium anisopliae (Metschn. Sorokin isolates were evaluated at 30 and 35 ºC. For each isolate, colony discs of 5 mm with mycelium were placed in the center of a Petri dish with Sabouraud dextrose agar (SDA medium. The dishes were incubated at 30 and 35 °C, without light. Radial growth of each colony was measured daily. All the B. bassiana and M. anisopliae isolates presented a lineal growth rate at a temperature of 30 ºC. However, at 35 ºC, most of the isolates did not grow, except three B. bassiana and 14 M. anisopliae isolates (P El objetivo de este trabajo fue seleccionar hongos entomopatógenos tolerantes a las temperaturas del nido de cría de las abejas (Apis mellifera, para ser utilizados en el control de Varroa destructor. Se evaluaron 50 aislamientos de Beauveria bassiana (Balsamo Vuillemin y 48 de Metarhizium anisopliae (Metschn. Sorokin a temperaturas de 30 y 35 ºC. Discos de agar de 5 mm de diámetro con micelio de colonias de cada aislamiento, se depositaron en el centro de placas Petri con medio agar Sabouraud dextrosa (ASD. Las placas fueron incubadas a 30 y 35 °C y oscuridad y diariamente se midió el radio de cada colonia. Todos los aislamientos de B. bassiana y M. anisopliae var. anisopliae presentaron una tendencia lineal a través del tiempo a temperaturas de incubación de 30 °C. A 35 °C la mayoría de los aislamientos no crecieron, excepto tres aislamientos de B. bassiana y 14 de M. anisopliae (p < 0,001. Estos aislamientos fueron seleccionados para realizar pruebas de patogenicidad sobre V. destructor, aplicando una suspensión de 10(7 conidias mL-1. El aislamiento más efectivo fue Qu-M845 de M. anisopliae (p = 0,0033, produjo una mortalidad de 85%. La capacidad patogénica de este aislamiento en V. destructor y su tolerancia a las condiciones ambientales a las que sería expuesto, permite considerar esta cepa como una alternativa de control para esta plaga.

  4. Fitoseídeos (Acari: Phytoseiidae associados a cafezais e fragmentos florestais vizinhos Phytoseiids (Acari: Phytoseiidae associated to coffee plantations and adjacent forest fragments

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    Ester Azevedo Silva

    2010-10-01

    Full Text Available Existem poucas informações sobre a fauna de ácaros predadores (Phytoseiidae em ambientes naturais brasileiros adjacentes a agroecossistemas cafeeiros (Coffea spp. ou sobre a influência que essa vegetação exerce como reservatório de ácaros predadores. Neste estudo, objetivou-se avaliar a diversidade destes organismos em cafeeiros e fragmentos florestais adjacentes. Coletaram-se amostras das espécies Calyptranthes clusiifolia (Miq. O. Berg (Myrtaceae, Esenbeckia febrifuga (A. St.-Hil. A. Juss. ex Mart. (Rutaceae, Metrodorea stipularis Mart. (Rutaceae e Allophylus semidentatus (Miq. Radlk. (Sapindaceae, em oito fragmentos florestais, de 5 a 51 ha, e cafezais adjacentes, nos meses de junho (final período chuvoso e outubro (final período seco nos anos 2004 e 2005, na região Sul do Estado de Minas Gerais. Ácaros foram extraídos das folhas, utilizando o método de lavagem e, em seguida, montados em lâminas de microscopia em meio de Hoyer, para identificação específica. No total foram identificados 2.348 fitoseídeos, sendo 2.090 nos fragmentos florestais e 258 espécimes nos cafezais adjacentes, pertencentes a 38 espécies. Servindo-se de análise faunística, a espécie Iphiseiodes zuluagai Denmark & Muma, 1972 apresentou os melhores índices no agroecossistema cafeeiro, sendo muito frequente e constante nas épocas estudadas. Nos fragmentos florestais Amblyseius herbicolus Chant, 1959, Iphiseiodes affs. neonobilis Denmark & Muma, 1978, Leonseius regularis DeLeon, 1965 e Euseius alatus DeLeon, 1966 foram dominantes, muito abundantes, muito frequentes e constantes nas épocas estudadas. Podemos concluir que a vegetação nativa abriga ácaros predadores, inimigos naturais de ácaros-praga, que ocorrem na cultura cafeeira, possibilitando o desenvolvimento de programas de manejo ecológico com áreas de vegetação natural e agroecossistemas cafeeiros adjacentes.There is little information about the fauna of predatory mites (Phytoseiidae in Brazilian natural environments, adjacent to coffee agroecosystems (Coffea spp., or about the influence exerted by neighbor vegetation as a reservoir of predatory mites. The objective of this study was to evaluate the diversity of these organisms in coffee plantations and adjacent forest fragments. Samples of the species Calyptranthes clusiifolia (Miq. O. Berg (Myrtaceae, Esenbeckia febrifuga (A. St.-Hil. A. Juss. ex Mart., Metrodorea stipularis Mart. (Rutaceae and Allophylus semidentatus (Miq. Radlk. (Sapindaceae were collected in eight forest fragments, from 5 to 51ha, adjacent to coffee plantations, in June (end of the rainy season and October (end of the dry season in the years of 2004 and 2005, in the Southern region of State of Minas Gerais. Leaf mites were extracted using the wash method, mounted in microscopy slides with Hoyer's medium for identification. A total of 2.348 phytoseiids was collected, being 2.090 in the forest fragments and 258 in adjacent coffee plantations, belonging to 38 species. According to fauna analysis, Iphiseiodes zuluaguai Denmark & Muma, the year of 1972 presented the best indexes in the coffee agroecosystem, being very frequent and constant in those periods. In the forest fragments, Amblyseius herbicolus Chant, 1959, Iphiseiodes affs. neonobilis Denmark & Muma, 1978, Leonseius regularis DeLeon, 1965 and Euseius alatus DeLeon, 1966 were dominant, very abundant, very frequent and constant in those periods. One may conclude that the native vegetation shelters predator mite, natural enemies of mite-pests that still occur in coffee culture, making possible ecological management program development involving areas of natural vegetation and adjacent coffee agroecosystems.

  5. Distribuição espacial e plano de amostragem de Calacarus heveae (Acari em seringueira Spatial distribution and sampling plan for Calacarus heveae (Acari on rubber trees

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    Noeli Juarez Ferla

    2007-12-01

    Full Text Available Calacarus heveae Feres, 1992 é um eriofídeo descrito de espécimes coletados em plantas de seringueira (Hevea brasiliensis, Euphorbiaceae na região noroeste do Estado de São Paulo. Esse ácaro prefere a face adaxial dos folíolos e pode causar a perda do brilho, amarelecimento, bronzeamento dessa região e a subseqüente queda prematura das folhas. O objetivo deste trabalho foi analisar a distribuição de C. heveae em seringueira, selecionar a unidade de amostragem mais representativa e desenvolver um plano de amostragem para o estudo de sua flutuação populacional. O trabalho foi conduzido com os clones PB 260 e IAN 873, respectivamente nos municípios de Itiquira e de Pontes e Lacerda, ambos no Mato Grosso. Em Itiquira, diferenças significativas foram observadas em quatro ocasiões em relação ao número médio de ácaros por folha nos diferentes estratos das plantas. Nas amostragens realizadas em Pontes e Lacerda, nenhuma diferença significativa foi encontrada entre os estratos em relação àquele parâmetro. Apenas em Itiquira, em uma ocasião de amostragem, foi verificada diferença entre os três estratos, em relação à proporção de folhas infestadas. Nenhuma diferença significativa foi verificada em relação ao número médio de ácaros por folha e proporção de folhas infestadas por C. heveae a diferentes distâncias da periferia da copa. Calacarus heveae exibe distribuição agregada no campo. Para estimar a densidade de C. heveae, um plano numérico e um plano binomial de amostragem foram desenvolvidos.Calacarus heveae Feres, 1992 (Eriophyidae is a mite described from specimens collected on rubber tree (Hevea brasiliensis, Euphorbiaceae in the northwest region of the state of São Paulo. This mite prefers the adaxial face of the folioles which it can turn dry, yellowish and brownish; it can also cause leaf fall. The aim of this work was to analyze the distribution of C. heveae on rubber trees, to select the most representative sampling unit and to develop a sampling plan to determine the populational fluctuation. This study was conducted with clones PB 260 and IAN 873, in Itiquira and Pontes e Lacerda, respectively, both in the state of Mato Grosso. In Itiquira, significant differences were observed in four occasions in relation to the average number of mites per leaf in the different plant strata. In the samplings carried out in Pontes e Lacerda, no significant differences were observed between strata in relation to that parameter. Only in Itiquira, in one occasion, a significant difference between strata was verified in relation to the proportion of infested leaves. No significant differences were verified in relation to the average number of mites per leaf and proportion of leaves infested by C. heveae at different depths in the canopy. Calacarus heveae exhibits aggregated distribution in the field. To estimate the density of C. heveae, numeric and sampling plans were developed.

  6. Nuevos registros de ácaros oribátidos (Acari: Oribatida para la Argentina New records of oribatid mites (Acari: Oribatida for Argentina

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    Cecilia Accattoli

    2010-12-01

    Full Text Available Esta publicación constituye un aporte al conocimiento del elenco oribatológico en suelos de Argentina, basado en relevamientos realizados en un parque urbano de la ciudad de La Plata, Buenos Aires. Se informan dos nuevas citas de géneros, una de subgénero y siete de especies para el país. Además, cinco de las especies halladas serían nuevas para la ciencia. Se incorporan ocho géneros y siete especies a las registradas para la Provincia de Buenos Aires.This paper is a contribution to the knowledge of assemblages of oribatid mites in soils of Argentina. The study is based on samples from an urban forest in the city of La Plata, Buenos Aires. New records for the country are provided for two genera, one subgenus and seven species. Furthermore, five of the species found are possibly new to science. Eight genera and seven species are incorporated to the record of the Buenos Aires province.

  7. Application of droplet digital PCR for quantitative detection of Spiroplasma citri in comparison with real time PCR

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    Droplet digital Polymerase chain reaction (ddPCR) is a unique approach to measure the absolute copy number of nucleic acid targets without the need of external standards. It is a promising DNA quantification technology for medical diagnostics but there are only a few reports of its use for plant pat...

  8. Compatibility and efficacy of Isaria fumosorosea with horticultural oils for mitigation of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae)

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    Horticultural oils are an important component of integrated management programs of several phytophagous arthropods, and pathogens affecting fruit, ornamental and vegetables in greenhouse and field production systems. Although effective against the target pest, their incompatibility with biological c...

  9. Efficacy of an autodisseminator of an entomopathogenic fungus, Isaria fumosorosea, to suppress Asian citrus psyllid, Diaphorina citri, under greenhouse conditions

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    The Asian citrus psyllid (ACP), transmits the causative agents of citrus greening disease or huanglongbing (HLB), the most devastating disease of citrus trees in the world today. ACP dwelling in noncommercial citrus (neighborhoods, commercial landscapes, etc.) can stymie area-wide management program...

  10. EFFECTIVENESS OF HUANGLONGBING VECTOR (DIAPHORINA CITRI KUWAYAMA CONTROL IN CITRUS GROWER GROUP BASED IN SAMBAS REGENCY OF WEST KALIMANTAN, INDONESIA

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    Supriyanto A.

    2017-12-01

    Full Text Available The purpose of this study was to determine the effectiveness of Huanglongbing vector control based on Citrus Grower Group recommendation. Studies have been carried out in 2010 in Tebas Sungai village, Sambas district, with 11 tangerine groves owned by growers in the Citrus grower Association of Sambas district. The tangerine grove that been used are, one grower's orchard as a demonstration plot in a particular citrus grower group (orchard I; five other citrus orchards with different ownership at the same citrus grower Group (orchard II, as well as five other citrus orchard with different ownership which each of them spreads over five different citrus grower groups outside the farm demonstration plots (orchard III. The recommendation technology for controlling Huanglongbing vector which applied in this experiment, included bark painting by systemic insecticide of imidacloprid for two each 1.5-month and spray using contact insecticide with dimethoate to the plant crown which application time been alternated after bark painting application. The effectiveness of technology implementation is measured by a decrease psyllid populations found in citrus samples in adult stage, nymphs and eggs that were observed at regular intervals every two weeks during the flushing to the 14th week after the first treatment. The results showed that recommended treatment technology were absolutely proven to reduce Huanglongbing vector population in significant, namely in the orchard I, II, and III respectively at 95.3%, 84.7%, and 72% for stage adult; 97.3 %, 80%, and 100% for stage nymphs; and 98.5%, 100% and 100% for the egg stage.

  11. Evaluation of systemic neonicotinoid insecticides for the management of the Asian citrus psyllid Diaphorina citri on containerized citrus.

    Science.gov (United States)

    Byrne, Frank J; Daugherty, Matthew P; Grafton-Cardwell, Elizabeth E; Bethke, James A; Morse, Joseph G

    2017-03-01

    Studies were conducted to evaluate uptake and retention of three systemic neonicotinoid insecticides, dinotefuran, imidacloprid and thiamethoxam, in potted citrus nursery plants treated at standard label rates. Infestation of these plants placed at a field site with moderate levels of Asian citrus psyllid (ACP) was monitored for 14 weeks following treatments, and insecticide residues in leaf tissue were quantified using enzyme-linked immunosorbent assay (ELISA). Bioassays were conducted using leaves harvested on various dates post-treatment to compare the efficacies of residues against adult ACP. Residues of the three neonicotinoids were detected in leaf tissues within 1 week after treatment. Peak concentrations established at 1 week for imidacloprid and dinotefuran and at 2 weeks for thiamethoxam. Imidacloprid and thiamethoxam outperformed the control and dinotefuran treatments at protecting trees from infestations by ACP eggs and nymphs. For a given insecticide concentration in leaf tissue, thiamethoxam induced the highest mortality of the three insecticides, and dinotefuran was the least toxic. If the time needed to achieve effective thresholds of a systemic neonicotinoid is known, treatments at production facilities could be scheduled that would minimize unnecessary post-treatment holding periods and ensure maximum retention of effective concentrations after the plants have shipped to retail outlets. The rapid uptake of the insecticides and retention at effective concentrations in containerized citrus suggest that the current 30 day post-treatment shipping restriction from production facilities to retail outlets outside of quarantine could be shortened to 14 days. Thiamethoxam should be added to the list of approved nursery treatments. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  12. Silencing abnormal wing disc gene of the Asian citrus psyllid, Diaphorina citri disrupts adult wing development and increases nymph mortality.

    Directory of Open Access Journals (Sweden)

    Ibrahim El-Shesheny

    Full Text Available Huanglongbing (HLB causes considerable economic losses to citrus industries worldwide. Its management depends on controlling of the Asian citrus Psyllid (ACP, the vector of the bacterium, Candidatus Liberibacter asiaticus (CLas, the causal agent of HLB. Silencing genes by RNA interference (RNAi is a promising tool to explore gene functions as well as control pests. In the current study, abnormal wing disc (awd gene associated with wing development in insects is used to interfere with the flight of psyllids. Our study showed that transcription of awd is development-dependent and the highest level was found in the last instar (5(th of the nymphal stage. Micro-application (topical application of dsRNA to 5(th instar of nymphs caused significant nymphal mortality and adult wing-malformation. These adverse effects in ACP were positively correlated with the amounts of dsRNA used. A qRT-PCR analysis confirmed the dsRNA-mediated transcriptional down-regulation of the awd gene. Significant down-regulation was required to induce a wing-malformed phenotype. No effect was found when dsRNA-gfp was used, indicating the specific effect of dsRNA-awd. Our findings suggest a role for awd in ACP wing development and metamorphosis. awd could serve as a potential target for insect management either via direct application of dsRNA or by producing transgenic plants expressing dsRNA-awd. These strategies will help to mitigate HLB by controlling ACP.

  13. CHECKLIST OF THE ERIOPHYOID MITE FAUNA OF MONTENEGRO (ACARI: PROSTIGMATA: ERIOPHYOIDEA

    OpenAIRE

    Jočić, Ivona; Petanović, Radmila

    2012-01-01

    Accounts are given of the eriophyoid fauna of Montenegro. Based on the literature records, a total of 156 mite species are listed from 130 host species of 42 plant families. The families Phytoptidae, Eriophidae and Diptilomiopidae are represented by 6, 138 and 12 species, respectively. Fifteen new species for science have been described from this area.

  14. New and little known species of ptyctimous mites (Acari, Oribatida) from Cameroon

    Czech Academy of Sciences Publication Activity Database

    Niedbala, W.; Starý, Josef

    2014-01-01

    Roč. 3889, č. 1 (2014), s. 31-57 ISSN 1175-5326 Institutional research plan: CEZ:AV0Z60660521 Institutional support: RVO:60077344 Keywords : ptyctimous mites * new species * taxonomy * morphology * Cameroon Subject RIV: EG - Zoology Impact factor: 0.906, year: 2014

  15. New and little known species of ptyctimous mites (Acari, Oribatida) from Costa Rica

    Czech Academy of Sciences Publication Activity Database

    Niedbala, W.; Starý, Josef

    2014-01-01

    Roč. 40, č. 4 (2014), s. 320-327 ISSN 0164-7954 Institutional research plan: CEZ:AV0Z60660521 Institutional support: RVO:60077344 Keywords : Oribatida * ptyctimous mites * taxonomy * descriptions * tritonymph Subject RIV: EG - Zoology Impact factor: 0.949, year: 2014

  16. Diversity and significance of eriophyoid mites (Acari: Eriophyoidea associated with coniferous trees in Poland: a review

    Directory of Open Access Journals (Sweden)

    Kiedrowicz Agnieszka

    2016-06-01

    Full Text Available Among the approximately 200 eriophyoid mite species associated with coniferous trees worldwide, 33 species (of the families Eriophyidae and Phytoptidae infest conifers in Poland, and 24 of them can cause visible feeding symptoms. In this paper we discuss the importance of eriophyoid mites to coniferous plants in Poland and their potential impact on the decorative value of ornamental plants. We emphasize the general lack of knowledge about the diversity of eriophyoid mites associated with coniferous trees and its role in the management and control of this economically important mite group.

  17. Detection of Leishmania (V guyanensis in Rhipicephalus (Boophilus microplus (Acari: Ixodidae collected from Pecari tajacu

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    Jesús E. Rojas-Jaimes

    2017-03-01

    Conclusion: The results showed the presence of L. (V guyanensis DNA in R. microplus possibly acquired after biting a collarde peccary. Therefore, it is important to design future studies to clarify R. microplus involvement in the transmission of leishmaniasis.

  18. Preliminary survey of ticks (Acari : Ixodidae on cattle in northern Sudan

    Directory of Open Access Journals (Sweden)

    D.A. Salih

    2004-11-01

    Full Text Available In a cross sectional survey conducted during the period June 2001 to July 2002, the geographical distribution of ticks on cattle in the Sudan was determined. Seventeen locations were surveyed from Northern, Central, Eastern, Western, Blue Nile and White Nile Provinces. Total body collections of ticks were made from 20 cattle at each location. Four tick genera and 11 species were identified. The tick species collected included Amblyomma lepidum, Amblyomma variegatum, Boophilus decoloratus, Hyalomma anatolicum anatolicum, Hyalomma dromedarii, Hyalomma impeltatum, Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus evertsi evertsi, Rhipicephalus sanguineus group and Rhipicephalus simus simus. Major ecological changes have occurred due to extensive animal movement, deforestation, desertification and establishment of large mechanized agricultural schemes. These factors have certainly affected the distribution of ticks and tick-borne diseases in the Sudan. The absence of A. variegatum and A. lepidum in northern Sudan was not surprising, since these tick species are known to survive in humid areas and not in the desert and semi-desert areas of northern Sudan. The absence of B. annulatus in northern and central Sudan is in accordance with the finding that this tick species is restricted to the southern parts of the central Sudan. The presence of H. anatolicum anatolicum in Um Benin in relatively high abundance is an interesting finding. The present finding may indicate that the southern limit of this species has changed and moved southwards to latitude 13o N. It is concluded that major changes in tick distribution have taken place in the Sudan

  19. Dermatophagoides pteronyssinus (Trouessart, 1897) in mattress and floor dust in a temperate climate (Acari : Pyroglyphidae)

    NARCIS (Netherlands)

    Bronswijk, van J.E.M.H.

    1973-01-01

    The arthropod fauna of mattress dust, bedroom dust and living-room dust was sampled during a 1-year period in a center for asthmatic children (near Nijmegen, The Netherlands) with the aid of a vacuum cleaner, Berlese funnels and a flotation method. Dermatophagoides pteronyssinus was most abundant;

  20. Toxicity and efficacy of selected pesticides and new acaricides to stored product mites (Acari : Acaridida)

    Czech Academy of Sciences Publication Activity Database

    Hubert, J.; Stejskal, V.; Münzbergová, Zuzana; Hajšlová, J.; Arthur, H. F.

    2007-01-01

    Roč. 42, č. 4 (2007), s. 283-290 ISSN 0168-8162 Grant - others:GA MŠk(CZ) 2B06099 Institutional research plan: CEZ:AV0Z60050516 Keywords : allergens * pesticide s * food Subject RIV: EF - Botanics Impact factor: 1.260, year: 2007

  1. Divergent methylation pattern in adult stage between two forms of Tetranychus urticae (Acari: Tetranychidae).

    Science.gov (United States)

    Yang, Si-Xia; Guo, Chao; Zhao, Xiu-Ting; Sun, Jing-Tao; Hong, Xiao-Yue

    2017-02-19

    The two-spotted spider mite, Tetranychus urticae Koch has two forms: green form and red form. Understanding the molecular basis of how these two forms established without divergent genetic background is an intriguing area. As a well-known epigenetic process, DNA methylation has particularly important roles in gene regulation and developmental variation across diverse organisms that do not alter genetic background. Here, to investigate whether DNA methylation could be associated with different phenotypic consequences in the two forms of T. urticae, we surveyed the genome-wide cytosine methylation status and expression level of DNA methyltransferase 3 (Tudnmt3) throughout their entire life cycle. Methylation-sensitive amplification polymorphism (MSAP) analyses of 585 loci revealed variable methylation patterns in the different developmental stages. In particular, principal coordinates analysis (PCoA) indicates a significant epigenetic differentiation between female adults of the two forms. The gene expression of Tudnmt3 was detected in all examined developmental stages, which was significantly different in the adult stage of the two forms. Together, our results reveal the epigenetic distance between the two forms of T. urticae, suggesting that DNA methylation might be implicated in different developmental demands, and contribute to different phenotypes in the adult stage of these two forms. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  2. Two new Anoplocheylus species (Acari: Trombidiformes: Pseudocheylidae) from Kurdistan province of Iran.

    Science.gov (United States)

    Khanjani, Mohammad; Hoseini, Mohammad Ahmad; Amini, Fatemeh

    2014-09-12

    Two new species of the genus Anoplocheylus Berlese, 1910 are described: Anoplocheylus marivaniensis sp. nov. collected from soil and rotten leaves under oak trees and Anoplocheylus qorvehiensis sp. nov. from soil under Astragalus sp. bushes in Kurdistan province, Iran. A key to females of all known species of Anoplocheylus is provided, based on original descriptions and other literature.

  3. How do Neoseiulus californicus (Acari: Phytoseiidae) females penetrate densely webbed spider mite nests?

    Science.gov (United States)

    Montserrat, M; de la Peña, F; Hormaza, J I; González-Fernández, J J

    2008-02-01

    The persea mite Oligonychus perseae is a pest of avocado trees that builds extremely dense webbed nests that protect them against natural enemies, including phytoseiid mites. Nests have one or two marginal entrances that are small and flattened. The predatory mite Neoseiulus californicus co-occurs with O. perseae in the avocado orchards of the south-east of Spain. Penetration inside nests through the entrances by this predator is thought to be hindered by its size and its globular-shaped body. However, in the field it has repeatedly been found inside nests that were clearly ripped. Perhaps penetration of the nests has been facilitated by nest wall ripping caused by some other species or by unfavourable abiotic factors. However, to assess whether N. californicus is also able to enter the nest of O. perseae by itself, we carried out laboratory experiments and made a short film. They show how this predator manages to overcome the webbed wall, and that it can penetrate and forage inside nests of O. perseae.

  4. A new species of the genus Epidamaeus (Acari, Oribatida, Damaeidae from China

    Directory of Open Access Journals (Sweden)

    Lixia Xie

    2011-07-01

    Full Text Available The oribatid mite genus Epidamaeus Bulanova-Zachvatkina, 1957 from China is reviewed, and a list and key to all known species from China are provided. A new species, Epidamaeus conjungenus, sp. n. is identified, and its morphological descriptions and illustrations are also given. The distinct characteristics of E. conjungenus sp. n. is the coterminous ridge connected to the base of the notogastral setae. Pseudanal setae undulating attenuate, the proximal half with obvious, thorn-like barbs, the distal half smooth.

  5. Complementary data on Haplozetes fusifer (Berlese, 1908 (Acari, Oribatida, Haplozetidae collected from Iran

    Directory of Open Access Journals (Sweden)

    Akrami, M. A.

    2013-12-01

    Full Text Available An oribatid mite of the family Haplozetidae, Haplozetes fusifer (Berlese, 1908 is redescribed on the basis of Iranian materials, including the first detailed descriptions of the gnathosoma and legs.Se redescribe un ácaro oribátido de la familia Haplozetidae, Haplozetes fusifer (Berlese, 1908, sobre la base de material iraní, incluyendo las primeras descripciones detalladas del gnatosoma y las patas.

  6. New and little known species of ptyctimous mites (Acari, Oribatida) from Madagascar

    Czech Academy of Sciences Publication Activity Database

    Niedbala, W.; Starý, Josef

    2016-01-01

    Roč. 4103, č. 6 (2016), s. 587-599 ISSN 1175-5326 Institutional research plan: CEZ:AV0Z60660521 Institutional support: RVO:60077344 Keywords : taxonomy * ptyctimous mites * new species * morphology * Madagascar Subject RIV: EG