WorldWideScience

Sample records for citri kuwayana hemiptera

  1. 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.

  2. 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 ...

  3. 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

    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.

  4. 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.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Evaluation of efficacy of 18 strains of entomopathogenic nematodes (Rhabditida) against Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae) under laboratory conditions.

    Science.gov (United States)

    Barbosa Negrisoli, Carla Ruth de Carvalho; Negrisoli Júnior, Aldomario Santo; Botton, Marcos; Garcia, Mauro Silveira; Bernardi, Daniel

    2013-07-01

    Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae) is an important plant virus vector in grapevine crops in Brazil and other countries. The mealybug grows in roots and leaves of the grapes. Entomopathogenic nematodes (EPNs) are efficient control agents against insects associated to the soil and could be applied with the same equipment used for chemical insecticides. The aim of this study was to select effective EPNs for controlling P. citri females in laboratory conditions (25±1°C, UR 60±10%). We tested 17 native [Steinernema rarum (6 strains), Steinernema glaseri, Steinernema feltiae, Steinernema riobrave, Steinernema sp., Heterorhabditis bacteriophora (7 strains)] and only one exotic strain (Steinernema carpocapsae ALL). The bioassays were done on Petri dishes infested with females of P. citri, which were sprayed with EPNs juveniles. The strain with larger pathogenicity and virulence in laboratory was H. bacteriophora RS33 (from 69.0% to 92.2% of mortality), native of Rio Grande do Sul.

  8. 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.

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

  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.

  11. 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...

  12. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

  15. 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.

  16. 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

  17. Polymerase chain reaction-restriction fragment length polymorphism method to distinguish three mealybug groups within the Planococcus citri-P. minor species complex (Hemiptera: Coccoidea: Pseudococcidae).

    Science.gov (United States)

    Rung, A; Miller, D R; Scheffer, S J

    2009-02-01

    The mealybug species Planococcus citri (Risso) and Planococcus minor (Maskell) (Hemiptera: Coccoidea: Pseudococcidae) have special significance to U.S. quarantine and U.S. agriculture. Commonly intercepted at U.S. ports-of-entry, they are difficult to identify based on morphological characters. This study presents a molecular method for distinguishing P. citri, P. minor, and a genetically distinct group that is morphologically identical to P. citri, from Hawaii. This method uses polymerase chain reaction (PCR) followed by restriction fragment polymorphism analysis (RFLP) using the restriction enzymes BspH1, BsmH1, and HpH1. The resulting band patterns can be visualized in a 2% agarose gel and are sufficient to differentiate between the three entities mentioned above. PCR-RFLP diagnostics can be used for all life stages and is cheaper and faster than DNA sequencing.

  18. Desenvolvimento de Planococcus citri (Risso, 1813 (Hemiptera: Pseudococcidae em cafeeiros = Development of Planococcus citri (Risso, 1813 (Hemiptera: Pseudococcidae in coffee trees

    Directory of Open Access Journals (Sweden)

    Lenira Viana Costa Santa-Cecília

    2009-01-01

    Full Text Available A cochonilha Planococcus citri (Risso, 1813 suga a seiva dos botões florais e frutos do cafeeiro, atacando as rosetas desde a floração até a colheita. Embora seja relatada há alguns anos na cafeicultura, são escassas as informações sobre o desenvolvimento dessacochonilha em cafeeiros. Assim, o presente trabalho teve por objetivos avaliar alguns aspectos biológicos da fase ninfal de P. citri em plantas de café. Ovos dessa cochonilha foram retirados de uma criação em laboratório, isolados em placas de Petri contendo discos foliares de Coffea arabica L., das cultivares Acaiá Cerrado, Mundo Novo e Catuaí Vermelho e de C. canephora Pierre & Froenher, cultivar Apoatã. As placas foram mantidas em câmara climatizada a 25 ± 1°C, 70 ± 10% de umidade relativa e 12h de fotofase. Constatou-se que a cultivar Catuaí Vermelho foi a que proporcionou maior duração do período ninfal das fêmeas, porém, não foram constatadas diferenças na mortalidade. Essa cochonilha se desenvolveu satisfatoriamente em todas as cultivares de café estudadas e os resultados não mostraram diferenças claras de susceptibilidade.The citrus mealybug Planococcus citri (Risso, 1813 feeds mainly on flowers and fruits of coffee plants from blooming until harvest. Little is known about its development in coffee although its occurrence is already known for several years. This work aims to study the nymph development of this mealybug in coffee plants.Eggs were isolated from a stock culture kept in laboratory and placed inside Petri dishes containing leaf sections in agar. The tested cultivars were Acaia Cerrado, Mundo Novo, Catuai Vermelho (Coffea arabica and Apoatã (C. canephora. Insects were kept in a climatizedchamber at 25ºC, 70 ± 10% humidity and 12-hour photophase. The longest development period in females was obtained in cultivar Catuai Vermelho. No differences in mortality were found among cultivars. Mealybugs developed in all cultivars and the results

  19. 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)

    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

  20. Daily and seasonal patterns in abdomen color in Diaphoria citri (Hemiptera: Psyllidae)

    Science.gov (United States)

    Diaphorina citri Kuwayama, a psyllid vector of huanglongbing (citrus greening disease), exhibits three more or less distinct abdomen colors in the adult psyllid: gray/brown, blue/green, and orange/yellow. We explored the daily (in individuals in the laboratory) and seasonal (in a field population) p...

  1. Effects of temperature, photoperiod, and rainfall on morphometric variation of Diaphorina citri (Hemiptera: Liviidae)

    Science.gov (United States)

    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 artifi...

  2. Population ecology and phenology of Diaphorina citri (Hemiptera: Psyllidae) in two Florida citrus groves

    Science.gov (United States)

    Studies were conducted during 2005 and 2006 to assess population densities and phenology of the psyllid Diaphorina citri Kuwayama in citrus within east central Florida. Young, irrigated grapefruit and mature, non-irrigated orange trees were sampled weekly for eggs, nymphs and adults on flush shoots;...

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

    Directory of Open Access Journals (Sweden)

    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. Adjuvants to improve aerial control of the citrus mealybug Planococcus citri (Hemiptera: Pseudococcidae) using entomopathogenic nematodes.

    Science.gov (United States)

    van Niekerk, S; Malan, A P

    2015-03-01

    The citrus mealybug, Planococcus citri, is a highly destructive pest of citrus, occurring only in the aerial parts of plants. Humidity will be one of the key factors to consider when using entomopathogenic nematodes (EPN) as biological control agents. Different adjuvants can be added to suspensions of EPNs, to improve control as a foliar application. An aqueous suspension containing Heterorhabditis zealandica and 0.3% Zeba® significantly increased P. citri mortality by 22% at 80% relative humidity (RH) with a temperature cycle starting at 22°C for 14 h and 11°C for 11 h. The same polymer formulation was tested for Steinernema yirgalemense and mortality of P. citri increased by 21% at 60% RH and by 27% at 80% RH. The addition of Nu-Film-P® and Zeba® to H. zealandica suspensions did not significantly retard application run-off on citrus leaves. The combination of Nu-Film-P® and Zeba®, however, was able to significantly retard sedimentation, increasing the average number of nematodes deposited on 2-cm2 leaf discs by 10 nematodes. In an aqueous suspension, nematodes settle rapidly to the bottom, resulting in an uneven distribution of nematodes. Xanthan gum, at a concentration of 0.2%, was highly effective at retarding sedimentation, with 72% of the initial nematode number still in suspension after 1 h. Zeba®, at a concentration of 0.3%, despite not being as effective as Xanthan gum, nevertheless still retarded sedimentation significantly. This is the first report of the potential of Nu-Film-P® and Zeba® to improve EPN performance against P. citri when used above ground in citrus orchards.

  5. 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.

  6. Insecticide sprays, natural enemy assemblages and predation on Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae).

    Science.gov (United States)

    Monzo, C; Qureshi, J A; Stansly, P A

    2014-10-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama is considered a key citrus pest due to its role as vector of 'huanglongbing' (HLB) or citrus greening, probably the most economically damaging disease of citrus. Insecticidal control of the vector is still considered a cornerstone of HLB management to prevent infection and to reduce reinoculation of infected trees. The severity of HLB has driven implementation of intensive insecticide programs against ACP with unknown side effects on beneficial arthropod fauna in citrus agroecosystems. We evaluated effects of calendar sprays directed against this pest on natural enemy assemblages and used exclusion to estimate mortality they imposed on ACP populations in citrus groves. Predator exclusion techniques were used on nascent colonies of D. citri in replicated large untreated and sprayed plots of citrus during the four major flushing periods over 2 years. Population of spiders, arboreal ants and ladybeetles were independently assessed. Monthly sprays of recommended insecticides for control of ACP, adversely affected natural enemy populations resulting in reduced predation on ACP immature stages, especially during the critical late winter/early spring flush. Consequently, projected growth rates of the ACP population were greatest where natural enemies had been adversely affected by insecticides. Whereas, this result does not obviate the need for insecticidal control of ACP, it does indicate that even a selective regimen of sprays can impose as yet undetermined costs in terms of reduced biological control of this and probably other citrus pests.

  7. Roles of olfactory cues, visual cues, and mating status in orientation of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) to four different host plants.

    Science.gov (United States)

    Wenninger, Erik J; Stelinski, Lukasz L; Hall, David G

    2009-02-01

    Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is an important worldwide pest of citrus that vectors bacteria (Candidatus Liberibacter spp.) responsible for huanglongbing (citrus greening disease). We examined the behavioral responses of mated and unmated D. citri of both sexes to odors from host plants in a Y-tube olfactometer, with and without visual cues. The host plants tested were 'Duncan' grapefruit (Citrus paradisi Macfayden), sour orange (Citrus aurantium L.), navel orange (C. sinensis L.), and Murraya paniculata L. Jack. Responses varied by plant species, psyllid sex and mating status, and the presence of a visual cue. Evidence of attraction generally was stronger in females and in mated individuals of both sexes relative to virgins. The presence of a visual cue typically enhanced attractiveness of olfactory cues; in no case did unmated individuals show evidence of attraction to host plant odors in the absence of avisual cue. In the absence of visual cues, mated females and males showed evidence of attraction only to odors from sour orange and navel orange, respectively. Psyllids exhibited anemotactic responses when assayed with plant odors alone but showed strong evidence of attraction only when olfactory and visual cues were combined, suggesting that olfactory cues facilitate orientation to host plants but may be insufficient alone. Antennal responses to citrus volatiles were confirmed by electroantennogram. The results reported here provide evidence that D. citri uses olfactory and visual cues in orientation to host plants and suggest the possibility of using plant volatiles in monitoring and management of this pest.

  8. Use of recombinant tobacco mosaic virus to achieve RNA interference in plants against the citrus mealybug, Planococcus citri (Hemiptera: Pseudococcidae.

    Directory of Open Access Journals (Sweden)

    Arif Muhammad Khan

    Full Text Available The citrus mealybug, Planococcus citri, is an important plant pest with a very broad plant host range. P. citri is a phloem feeder and loss of plant vigor and stunting are characteristic symptoms induced on a range of host plants, but P. citri also reduces fruit quality and causes fruit drop leading to significant yield reductions. Better strategies for managing this pest are greatly needed. RNA interference (RNAi is an emerging tool for functional genomics studies and is being investigated as a practical tool for highly targeted insect control. Here we investigated whether RNAi effects can be induced in P. citri and whether candidate mRNAs could be identified as possible targets for RNAi-based P. citri control. RNAi effects were induced in P. citri, as demonstrated by specific target reductions of P. citri actin, chitin synthase 1 and V-ATPase mRNAs after injection of the corresponding specific double-stranded RNA inducers. We also used recombinant Tobacco mosaic virus (TMV to express these RNAi effectors in Nicotiana benthamiana plants. We found that P. citri showed lower fecundity and pronounced death of crawlers after feeding on recombinant TMV-infected plants. Taken together, our data show that actin, chitin synthase 1 and V-ATPase mRNAs are potential targets for RNAi against P. citri, and that recombinant TMV is an effective tool for evaluating candidate RNAi effectors in plants.

  9. Use of recombinant tobacco mosaic virus to achieve RNA interference in plants against the citrus mealybug, Planococcus citri (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Khan, Arif Muhammad; Ashfaq, Muhammad; Kiss, Zsofia; Khan, Azhar Abbas; Mansoor, Shahid; Falk, Bryce W

    2013-01-01

    The citrus mealybug, Planococcus citri, is an important plant pest with a very broad plant host range. P. citri is a phloem feeder and loss of plant vigor and stunting are characteristic symptoms induced on a range of host plants, but P. citri also reduces fruit quality and causes fruit drop leading to significant yield reductions. Better strategies for managing this pest are greatly needed. RNA interference (RNAi) is an emerging tool for functional genomics studies and is being investigated as a practical tool for highly targeted insect control. Here we investigated whether RNAi effects can be induced in P. citri and whether candidate mRNAs could be identified as possible targets for RNAi-based P. citri control. RNAi effects were induced in P. citri, as demonstrated by specific target reductions of P. citri actin, chitin synthase 1 and V-ATPase mRNAs after injection of the corresponding specific double-stranded RNA inducers. We also used recombinant Tobacco mosaic virus (TMV) to express these RNAi effectors in Nicotiana benthamiana plants. We found that P. citri showed lower fecundity and pronounced death of crawlers after feeding on recombinant TMV-infected plants. Taken together, our data show that actin, chitin synthase 1 and V-ATPase mRNAs are potential targets for RNAi against P. citri, and that recombinant TMV is an effective tool for evaluating candidate RNAi effectors in plants.

  10. Botanicals, selective insecticides, and predators to control Diaphorina citri (Hemiptera: Liviidae) in citrus orchards.

    Science.gov (United States)

    Khan, Azhar A; Afzal, Muhammad; Qureshi, Jawwad A; Khan, Arif M; Raza, Abubakar M

    2014-12-01

    The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama vectors pathogens that cause huanglongbing (HLB) or citrus greening devastating and economically important disease present in most citrus growing regions. Young citrus shoots are required for psyllid reproduction and development. During winter citrus trees produce little or no new growth. Overwintering adults reproduce in spring on newly emerging shoots also attractive to other pests and beneficial insects. Botanicals and relatively selective insecticides could help to conserve beneficial insects and reduce pest resistance to insecticides. Sprays of Azadirachtin (Neem), Tropane (Datura), Spirotetramat, Spinetoram, and broad-spectrum Imidacloprid were evaluated to control ACP in spring and summer on 10-year-old "Kinow" Citrus reticulata Blanco trees producing new growth. Psyllid populations were high averaging 5-9 nymphs or adults per sample before treatment application. Nymphs or adults were significantly reduced to 0.5-1.5 per sample in all treatments for 3 weeks, average 61%-83% reduction. No significant reduction in ladybeetles Adalia bipunctata, Aneglei scardoni, Cheilomenes sexmaculata, and Coccinella septempunctata was observed. Syrphids, spiders and green lacewings were reduced in treated trees except with Tropane. Studies are warranted to assess impact of these predators on ACP and interaction with insecticides. Observed reduction in ACP populations may not be enough considering its reproductive potential and role in the spread of HLB. Follow-up sprays may be required to achieve additional suppression using rotations of different insecticides.

  11. 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 ...

  12. 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.

  13. Temporal response and attraction of Diaphorina citri to visual stimuli

    Science.gov (United States)

    As the vector of the global disease of citrus greening or huanglongbing, Asian citrus pysllids, Diaphorina citri Kuwayama (Hemiptera; Liviidae) are the greatest threat to the worldwide citrus industry. Critical to management of D. citri and huanglongbing, is optimization of surveillance methodologie...

  14. Aspectos biológicos de Chrysoperla externa (Hagen, 1861(Neuroptera: Chrysopidae alimentada com Planococcus citri (Risso, 1813(Hemiptera: Pseudococcidae e Toxoptera citricida (Kirkaldy, 1907 (Hemiptera: Aphididae Bipogical aspects of Chrysoperla externa (Hagen, 1861 (Neuroptera: Chrysopidae fed with Planococcus citri (Risso, 1813 (Hemiptera: Pseudococcidae and Toxoptera citricida (Kirkaldy, 1907 (Hemiptera: Aphididae (Hemiptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Jean Patrick Bonani

    2009-02-01

    Full Text Available O ecossistema citrícola abriga muitas espécies de inimigos naturais, entre eles Chrysoperla externa (Hagen, 1861 que apresenta um grande potencial como agente de controle biológico de pragas. Neste trabalho, objetivou-se avapar o efeito das presas Planococcus citri (Risso, 1813 e Toxoptera citricida (Kirkaldy, 1907 sobre o desenvolvimento das fases de larva e pupa de C. externa. O ensaio foi conduzido em sala cpmatizada a uma temperatura de 25±1ºC, 70±10% UR e fotofase de 12 horas, sendo os tratamentos constituídos pelo fornecimento contínuo e alternado dessas duas presas em cada ínstar do predador, além de ovos de Anagasta kuehniella (Zeller, 1879, utilizados para fins de comparação. Foram avaliados o tempo de vida e a viabilidade das fases de larva, pupa e do período larva-adulto de C. externa. Constatou-se que T. citricida fornecido isoladamente ao longo do desenvolvimento larval ou em dois ínstares consecutivos do predador, não foi uma presa adequada, constatando-se 100% de mortalidade no período larva-adulto. Quando as larvas alimentaram-se de P. citri fornecida em dois ínstares do predador, a viabilidade no período larva-adulto foi semelhante à dieta constituída por apenas ovos de A. kuehniella, exceto quando se alimentaram de T. citricida no primeiro ínstar.The citrus-growing ecosystem houses a great deal of species of natural enemies, among them Chrysoperla externa (Hagen, 1861, which presents a great potential for use in the bipogical contrp of pests. The aim of this work was to evaluate the effects of the preys Planococcus citri (Risso, 1813 and Toxoptera citricida (Kirkaldy, 1907 on the development of larva and pupa of C. externa. The trial was carried out in an accpmatized room at 25±1ºC, 70±10% RH and 12-hour photophase, the treatments consisting of the continuous and alternate supply of those two preys in each instar of the predator, in apition to eggs of Anagasta kuehniella (Zeller, 1879 utilized for

  15. Control químico de Diaphorina citri Kuwayama (Hemíptera: Psyllidae en lima persa Citrus latifolia Tanaka Chemical control of Diaphorina citri Kuwayama (Hemiptera: Psyllidae in Persian lime Citrus latifolia Tanaka

    Directory of Open Access Journals (Sweden)

    Luis Martín Hernández-Fuentes

    2012-06-01

    Full Text Available A nivel mundial, la citricultura representa una actividad de gran importancia. México ocupa el cuarto lugar mundial en producción. Debido a la introducción y dispersión del vector D. citri en todas las zonas citrí colas de México y la reciente detección de la enfermedad conocida como huanglongbing causada por la bacteria Candidatus Liberibacter asiaticus, es necesaria la evaluación de métodos de control de este insecto. En el año 2010 en Nayarit, México, se realizaron pruebas de efectividad técnica en campo y persistencia de productos químicos de diferente mecanismo de acción contra D. citri en lima persa. Se hicieron dos evaluaciones en fechas distintas. En cada ensayo se evaluó número de ninfas por brote y porcentaje de brotes infestados. De los productos evaluados el dimetoato, imidacloprid y la mezcla de imidacloprid más betaciflutrina ejercieron más de 85 % de control de ninfas durante 27 días después de la aplicación. En los árboles tratados con dimetoato e imidacloprid en dosis de 400 mL y 300 mL ha-¹, respectivamente, se observó 100% de brotes libres de ninfas de D. citri a los 27 días después de la aplicación. El aceite agrícola en dosis de dos y tres L ha-1 ejerció menor control de ninfas de D. citri.Citrus crops represent an outstanding activity at worldwide level. Mexico ranks fourth place in production. Due introduction and dispersion of D. citri vector in all citric zones from Mexico and the newly detected disease known as huanglongbing (HLB caused by Candidatus Liberibacter asiaticus bacteria, assessment of control methods for this bug is required. In 2010, technical effectiveness in field and persistence for different action route against Persian lime D. citri chemical products tests were performed in Nayarit, Mexico. Two assessments were made at different dates. The amount of nymphs per shoot and percentage of infested shoots were assessed in each rehearsal. From evaluated products, dimethoate

  16. 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...

  17. Survey of endosymbionts in the Diaphorina citri metegenome and assembly of a Wolbachia wDi draft genome

    Science.gov (United States)

    Diaphorina citri, the Asian citrus psyllid,(Hemiptera) is the insect vector of Candidatus Liberibacter asiaticus, the presumed cause of citrus greening disease, known as huanglongbing. Sequencing of the Diaphorina citri metagenome has been initiated to gain better understanding of the biology of D. ...

  18. Sequencing and annotation of the Wolbachia endosymbiont of Diaphorina citri by the CG-HLB genome resources group reveals candidate sources of interaction with the insect host

    Science.gov (United States)

    Diaphorina citri (Hemiptera: Psyllidae), the Asian citrus psyllid, is the vector of Ca. Liberibacter asiaticus, the causal agent of huanglongbing. The D. citri metagenome has been completed to gain a better understanding of the biology of this organism and the potential roles of other psyllid bacter...

  19. Coccidoxenoides perminutus parasitizing Planococcus citri on vine in Brazil

    Directory of Open Access Journals (Sweden)

    Maria Herlândia de Araújo Fernandes

    2016-07-01

    Full Text Available ABSTRACT: From those of the mealybug family, the citrus mealybug, Planococcus citriRisso, 1813 (Hemiptera: Pseudococcidae is frequently held responsible for various diseases occurring in vineyards. This is a first time report in Brazil, on the occurrence of a parasitoid controlling P. citri. In our search for the natural enemies of P. citri, bunches of grapes with the vine were collected every week for one month, in those regions where table grapes were produced, like Petrolina, Pernambuco, Brazil. In these samples, among the natural pest infestations Coccidoxenoides perminutusGirault, 1915 (Hymenoptera: Encyrtidae was the only natural enemy species reported. In this research, we attempted to study the potential of parasitism as well as the strategies that this natural agent uses in pest control.

  20. Gender differences and effect of photophase on Asian citrus psyllid (Diaphorina citri Kuwayama) feeding behavior

    Science.gov (United States)

    Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), thought to be primarily a phloem-feeding insect, transmits the presumptive pathogen for Huanglongbing, ‘Candidatus Liberibacter asiaticus’. Because this bacterium is restricted to the phloem and bacterial transmission is the res...

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

    Science.gov (United States)

    Huanglongbing (HLB) is the most destructive disease of citrus worldwide. 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. Laboratory and field studies were cond...

  2. 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

    Directory of Open Access Journals (Sweden)

    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

  3. Wolbachia infection density in populations of the Asian citrus psyllid (Hemiptera: Liviidae).

    Science.gov (United States)

    Hoffmann, M; Coy, M R; Kingdom Gibbard, H N; Pelz-Stelinski, K S

    2014-10-01

    The symbiotic relationships between bacteria of the genus Wolbachia (order Rickettsiales) and their arthropod hosts are diverse and can range from mutualism to parasitism. Whereas effects of Wolbachia on host biology are well investigated, little is known about diversity and abundance of Wolbachia in their natural hosts. The phloem-feeding Asian citrus psyllid, Diaphorina citri (Kuwayama) (Hemiptera: Liviidae), is naturally infected with Wolbachia (wDi). In the current study, we calculated the within-host density of Wolbachia in Florida D. citri populations using quantitative polymerase chain reaction for detection of the Wolbachia outer surface protein gene, wsp. Gene quantities were normalized to the D. citri wingless gene (Wg) to estimate Wolbachia abundance in individual D. citri. Using this method, significant geographic differences in Wolbachia densities were detected among Florida D. citri populations, with higher infection levels occurring in male versus female hosts.

  4. Construction and evaluation of yeast two-hybrid cDNA library of Diaphorina citri (Hemiptera: Psyllidae)%柑橘木虱酵母双杂交cDNA文库的构建及评价

    Institute of Scientific and Technical Information of China (English)

    马晓芳; 陈国庆; 张学潮; 徐海君

    2013-01-01

    In order to study the interacting proteins between the Asian citrus psyllid ( Diaphorina citri) and Candidatus Liberibacter asiaticus ( CLas) which is the pathogenic bacterium causing Huanglongbing, yeast two-hybrid cDNA library of D. citri was constructed using the Switching Mechanism at 5' End of the RNA Transcript (SMART) technique. The total RNA was isolated from the citrus psyllid adults bred in the laboratory and subjected to reverse transcription, and the double-strand cDNAs ( ds cDNAs) were synthesized. The ds cDNAs were ligated with homologous adapter and purified by the chromatography column. By using homologous recombination reaction, the ds cDNAs were transformed into the Y187 competent cell with the library plasmid pGADT7-Rec to construct yeast two-hybrid cDNA library. Detection of the library indicated that it contained more than 106 independent clones, the titer of the amplified library was 2. 23 × 10 cfu/mL, and the average size of inserts was above 750 bp in the cDNA library. These results demonstrate that the library meets the requirements of the standard cDNA library. Moreover, two membrane proteins, ORF420 and ORF3420, from ( CLas) were used as bait proteins to screen the interacting proteins in the library, but no positive clone was screened in the tests. The yeast two-hybrid cDNA library of D. citri will be useful for the research on the interaction between insect vectors and C. Liberibacter asiaticus in the future.%为了探索研究柑橘木虱Diaphorina citri与柑橘黄龙病(Huanglongbing,HLB)病原菌的相互作用蛋白,本研究运用RNA转录中5 '末端转换机制(Switching Mechanism at 5'End of the RNA Transcript,SMART)技术构建了柑橘木虱的酵母双杂交cDNA文库.以实验室饲养的柑橘木虱为材料,提取总RNA,经反转录后合成ds cDNA,两端添加同源重组序列,并用层析柱纯化;ds cDNA与文库质粒pGADT7-Rec在酵母Y187感受态细胞内发生同源重组,柑橘木虱cDNA重组到文库质粒

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    Raiinder S.Mann; Russell L.Rouseff; Jack Smoot; Nandikeswara Rao; Wendy L.Meyer; Stephen L.Lapointe; Paul S.Robbins

    2013-01-01

    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.cirri 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).

  7. Attraction of Diaphorina citri (Hemiptera: Liviidae) to colored light

    Science.gov (United States)

    The most devasting disease of citrus, huanglongbing (HLB), is spread by the insect vector the Asian Citrus Psyllid (ACP). Although ACP are known to respond to visual cues, previous studies have not documented the specific wavelengths of light attractive to ACP. The objectives of this study were to...

  8. Proposal to conserve the name Phomopsis citri H.S. Fawc. (Diaporthe citri), with a conserved type, against Phomopsis citri (Sacc.) Traverso & Spessa (Ascomycota, Diaporthales, Diaporthaceae)

    Science.gov (United States)

    The name Diaporthe citri applies to a fungus that causes a disease on Citrus known as melanose or stem end rot of mature fruit after harvest and occurs widely in North America and Asia. Initially described as the illegitimate Phomopsis citri H.S. Fawc. 1912, non P. citri (Sacc.) Traverso & Spessa 19...

  9. Foliar application of biofilm formation-inhibiting compounds enhances control of citrus canker caused by Xanthomonas citri subsp. citri.

    Science.gov (United States)

    Li, Jinyun; Wang, Nian

    2014-02-01

    Citrus canker caused by the bacterium Xanthomonas citri subsp. citri is an economically important disease of citrus worldwide. Biofilm formation plays an important role in early infection of X. citri subsp. citri on host leaves. In this study, we assessed the hypothesis that small molecules inhibiting biofilm formation reduce X. citri subsp. citri infection and enhance the control of citrus canker disease. D-leucine and 3-indolylacetonitrile (IAN) were found to prevent biofilm formation by X. citri subsp. citri on different abiotic surfaces and host leaves at a concentration lower than the minimum inhibitory concentration (MIC). Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis indicated that IAN repressed expression of chemotaxis/motility-related genes in X. citri subsp. citri. In laboratory experiments, planktonic and biofilm cells of X. citri subsp. citri treated with D-leucine and IAN, either alone or in combination, were more susceptible to copper (CuSO4) than those untreated. In greenhouse assays, D-leucine and IAN applied alone or combined with copper reduced both the number of canker lesions and bacterial populations of X. citri subsp. citri on citrus host leaves. This study provides the basis for the use of foliar-applied biofilm inhibitors for the control of citrus canker alone or combined with copper-based bactericides.

  10. Fortunella margarita Transcriptional Reprogramming Triggered by Xanthomonas citri subsp. citri

    Directory of Open Access Journals (Sweden)

    Khalaf Abeer A

    2011-11-01

    Full Text Available Abstract Background Citrus canker disease caused by the bacterial pathogen Xanthomonas citri subsp. citri (Xcc has become endemic in areas where high temperature, rain, humidity, and windy conditions provide a favourable environment for the dissemination of the bacterium. Xcc is pathogenic on many commercial citrus varieties but appears to elicit an incompatible reaction on the citrus relative Fortunella margarita Swing (kumquat, in the form of a very distinct delayed necrotic response. We have developed subtractive libraries enriched in sequences expressed in kumquat leaves during both early and late stages of the disease. The isolated differentially expressed transcripts were subsequently sequenced. Our results demonstrate how the use of microarray expression profiling can help assign roles to previously uncharacterized genes and elucidate plant pathogenesis-response related mechanisms. This can be considered to be a case study in a citrus relative where high throughput technologies were utilized to understand defence mechanisms in Fortunella and citrus at the molecular level. Results cDNAs from sequenced kumquat libraries (ESTs made from subtracted RNA populations, healthy vs. infected, were used to make this microarray. Of 2054 selected genes on a customized array, 317 were differentially expressed (P Conclusion Functional categorization of kumquat Xcc-responsive genes revealed an enhanced defence-related metabolism as well as a number of resistant response-specific genes in the kumquat transcriptome in response to Xcc inoculation. Gene expression profile(s were analyzed to assemble a comprehensive and inclusive image of the molecular interaction in the kumquat/Xcc system. This was done in order to elucidate molecular mechanisms associated with the development of the hypersensitive response phenotype in kumquat leaves. These data will be used to perform comparisons among citrus species to evaluate means to enhance the host immune responses

  11. 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.

  12. 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

    2017-01-23

    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, LD50 values were determined and ranged from 0.10 to 0.53 ng/μl for imidacloprid, fenpropathrin, dimethoate and spinetoram. LD50 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.

  13. Complete Genome Sequences of Six Copper-Resistant Xanthomonas citri pv. citri Strains Causing Asiatic Citrus Canker, Obtained Using Long-Read Technology

    Science.gov (United States)

    Richard, Damien; Boyer, Claudine; Vernière, Christian; Canteros, Blanca I.; Lefeuvre, Pierre

    2017-01-01

    ABSTRACT The gammaproteobacterium Xanthomonas citri pv. citri causes Asiatic citrus canker. Pathotype A strains have a broad host range, which includes most commercial citrus species, and they cause important economic losses worldwide. Control often relies on frequent copper sprays. We present here the complete genomes of six X. citri pv. citri copper-resistant strains. PMID:28336584

  14. 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)

  15. Characterization of a variant of Xanthomonas citri subsp. citri that triggers a host-specific defense response.

    Science.gov (United States)

    Chiesa, María A; Siciliano, María F; Ornella, Leonardo; Roeschlin, Roxana A; Favaro, María A; Delgado, Natalia Pino; Sendín, Lorena N; Orce, Ingrid G; Ploper, L Daniel; Vojnov, Adrian A; Vacas, José Gadea; Filippone, María P; Castagnaro, Atilio P; Marano, María R

    2013-06-01

    Citrus is an economically important fruit crop that is severely afflicted by Asiatic citrus bacterial canker (CBC), a disease caused by the phytopathogen Xanthomonas citri subsp. citri (X. citri). To gain insight into the molecular epidemiology of CBC, 42 Xanthomonas isolates were collected from a range of Citrus spp. across 17 different orchards in Tucumán, Argentina and subjected to molecular, biochemical, and pathogenicity tests. Analysis of genome-specific X. citri markers and DNA polymorphisms based on repetitive elements-based polymerase chain reaction showed that all 42 isolates belonged to X. citri. Interestingly, pathogenicity tests showed that one isolate, which shares >90% genetic similarity to the reference strain X. citri T, has host range specificity. This new variant of X. citri subsp. citri, named X. citri A(T), which is deficient in xanthan production, induces an atypical, noncankerous chlorotic phenotype in Citrus limon and C. paradisi and weak cankerous lesions in C. aurantifolia and C. clementina leaves. In C. limon, suppression of canker development is concomitant with an oxidative burst; xanthan is not implicated in the phenotype induced by this interaction, suggesting that other bacterial factors would be involved in triggering the defense response.

  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. Scientific Opinion on the risk to plant health of Xanthomonas citri pv. citri and Xanthomonas citri pv. aurantifolii for the EU territory

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Plant Health (PLH

    2014-02-01

    Full Text Available The Panel conducted a pest risk assessment for Xanthomonas campestris (all strains pathogenic to Citrus for the EU territory and an assessment of the effectiveness of present EU requirements against Xanthomonas strains pathogenic to citrus. The risk assessment was conducted under the scenario of absence of the current specific EU plant health legislation and the assumption that citrus-exporting countries apply measures to reduce yield and quality losses. Risk reduction options were systematically identified and evaluated. The strains of X. campestris pathogenic to citrus have been reclassified as four distinct infraspecific taxa within two species: X. citri and X. alfalfae. Only two pathovars (X. citri pv. citri and X. citri pv. aurantifolii are responsible for the citrus bacterial canker thatpresents a major risk for the citrus industry in the EU. Seven entry pathways have been identified and evaluated. The likelihood of entry was rated unlikely for fruit, very likely for fruit plants for planting, moderately likely for ornamental plants for planting and unlikely for leaves and twigs. The uncertainty of probability of entry was rated as high. The probability of establishment was rated as moderately likely to likely with a medium uncertainty because host plants are widely present in EU areas where environmental conditions are suitable. Once established, spread would be likely with a low uncertainty. The impact of the disease, even if control measures are applied, was rated as moderate to major with a medium uncertainty. The disease would cause yield losses in areas where citrus is the main crop, increase the need for control measures and create environmental problems.The combined EU regulations have been shown to be effective in preventing the introduction of X. citri pv. citri or X. citri pv. aurantifolii in the EU, as no outbreaks of citrus canker in the EU territory have been reported.

  18. Selection of Small Synthetic Antimicrobial Peptides Inhibiting Xanthomonas citri subsp. citri Causing Citrus Canker

    Science.gov (United States)

    Choi, Jeahyuk; Park, Euiho; Lee, Se-Weon; Hyun, Jae-Wook; Baek, Kwang-Hyun

    2017-01-01

    Citrus canker disease decreases the fruit quality and yield significantly, furthermore, emerging of streptomycin-resistant pathogens threatens the citrus industry seriously because of a lack of proper control agents. Small synthetic antimicrobial peptides (AMPs) could be a promising alternative. Fourteen hexapeptides were selected by using positional scanning of synthetic peptide combinatorial libraries. Each hexapeptide showed different antimicrobial spectrum against Bacillus, Pseudomonas, Xanthomonas, and Candida species. Intriguingly, BHC10 showed bactericidal activity exclusively on Xanthomonas citri subsp. citri (Xcc), while BHC7 was none-active exclusively against two Pseudomonas spp. at concentration of 100 μg/ml suggesting potential selectivity constrained in hexapeptide frame. Three hexapeptides, BHC02, 06 and 11, showed bactericidal activities against various Xcc strains at concentration of 10 μg/ml. When they were co-infiltrated with pathogens into citrus leaves the disease progress was suppressed significantly. Further study would be needed to confirm the actual disease control capacity of the selected hexapeptides. PMID:28167892

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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/.

  1. A protein expression system for tandem affinity purification in Xanthomonas citri subsp. citri

    Directory of Open Access Journals (Sweden)

    Giordanni C. Dantas

    2016-06-01

    Full Text Available Abstract Citrus canker, caused by the Gram-negative bacterium Xanthomonas citri subsp. citri (Xac, is one of the most devastating diseases to affect citrus crops. There is no treatment for citrus canker; effective control against the spread of Xac is usually achieved by the elimination of affected plants along with that of asymptomatic neighbors. An in depth understanding of the pathogen is the keystone for understanding of the disease; to this effect we are committed to the development of strategies to ease the study of Xac. Genome sequencing and annotation of Xac revealed that ∼37% of the genome is composed of hypothetical ORFs. To start a systematic characterization of novel factors encoded by Xac, we constructed integrative-vectors for protein expression specific to this bacterium. The vectors allow for the production of TAP-tagged proteins in Xac under the regulation of the xylose promoter. In this study, we show that a TAP-expression vector, integrated into the amy locus of Xac, does not compromise its virulence. Furthermore, our results also demonstrate that the polypeptide TAP can be overproduced in Xac and purified from the soluble phase of cell extracts. Our results substantiate the use of our vectors for protein expression in Xac thus contributing a novel tool for the characterization of proteins and protein complexes generated by this bacterium in vivo.

  2. treA Codifies for a Trehalase with Involvement in Xanthomonas citri subsp. citri Pathogenicity

    Science.gov (United States)

    Alexandrino, André Vessoni; Goto, Leandro Seiji; Novo-Mansur, Maria Teresa Marques

    2016-01-01

    Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xcc), is a severe disease of citrus. Xcc presents broad spectrum of citrus hosts including economically important species whereas X. fuscans subsp. aurantifolii–type C (XauC) causes a milder disease and only infects Citrus aurantifolia. Trehalase catalyzes hydrolysis of the disaccharide trehalose, a sugar that has been reported to be related to Xcc pathogenicity. We expressed the recombinant gene product and assessed Xcc trehalase structural and kinetics data. The recombinant protein presented 42.7% of secondary structures in α-helix and 13% in β-sheets, no quaternary structure in solution, and Michaelis-Menten constant (KM) of 0.077 mM and Vmax 55.308 μMol glucose.min-1.mg protein-1 for trehalose. A Xcc mutant strain (XccΔtreA) was produced by gene deletion from Xcc genome. Enzymatic activity of trehalase was determined in Xcc, XauC and XccΔtreA cellular lysates, showing the highest values for XauC in in vitro infective condition and no activity for XccΔtreA. Finally, leaves of Citrus aurantifolia infected with XccΔtreA showed much more drenching and necrosis than those infected by wild type Xcc. We concluded that trehalase contributes to alleviate bacterial virulence and that inability for trehalose hydrolysis may promote higher Xcc infectivity. PMID:27611974

  3. Bioactive Organocopper Compound from Pseudomonas aeruginosa Inhibits the Growth of Xanthomonas citri subsp. citri

    Science.gov (United States)

    de Oliveira, Admilton G.; Spago, Flavia R.; Simionato, Ane S.; Navarro, Miguel O. P.; da Silva, Caroline S.; Barazetti, André R.; Cely, Martha V. T.; Tischer, Cesar A.; San Martin, Juca A. B.; de Jesus Andrade, Célia G. T.; Novello, Cláudio R.; Mello, João C. P.; Andrade, Galdino

    2016-01-01

    Citrus canker is a very destructive disease of citrus species. The challenge is to find new compounds that show strong antibiotic activity and low toxicity to plants and the environment. The objectives of the present study were (1) to extract, purify and evaluate the secondary metabolites with antibiotic activity produced by Pseudomonas aeruginosa LV strain in vitro against Xanthomonas citri subsp. citri (strain 306), (2) to determine the potential of semi-purified secondary metabolites in foliar application to control citrus canker under greenhouse conditions, and (3) to identify antibiotic activity in orange leaf mesophyll infected with strain 306, by electron microscopy. Two pure bioactive compounds were isolated, an organocopper antibiotic compound (OAC) and phenazine-1-carboxamide. Phenazine-1-carboxamide did not show any antibiotic activity under the experimental conditions used in this study. The OAC showed a high level of antibiotic activity with a minimum inhibitory concentration of 0.12 μg mL-1. In greenhouse tests for control of citrus canker in orange trees, the semi-purified fraction F3d reduced lesion formation by about 97%. The concentration used was 500 times lower than that for the recommended commercial copper-based product. Electron microscopy showed that F3d altered the exopolysaccharide matrix and caused cell lysis of the pathogen inside the citrus canker lesions. These results suggest that secondary metabolites produced by inducing P. aeruginosa LV strain have a high potential to be used as a bioproduct to control citrus canker. PMID:26903992

  4. 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

    2014-06-01

    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.

  5. Molecular and morphological identification of mealybug species (Hemiptera: Pseudococcidae in Brazilian vineyards.

    Directory of Open Access Journals (Sweden)

    Vitor C Pacheco da Silva

    Full Text Available Mealybugs (Hemiptera: Pseudococcidae are pests constraining the international trade of Brazilian table grapes. They damage grapes by transmitting viruses and toxins, causing defoliation, chlorosis, and vigor losses and favoring the development of sooty mold. Difficulties in mealybug identification remain an obstacle to the adequate management of these pests. In this study, our primary aim was to identify the principal mealybug species infesting the major table grape-producing regions in Brazil, by morphological and molecular characterization. Our secondary aim was to develop a rapid identification kit based on species-specific Polymerase Chain Reactions, to facilitate the routine identification of the most common pest species. We surveyed 40 sites infested with mealybugs and identified 17 species: Dysmicoccus brevipes (Cockerell, Dysmicoccus sylvarum Williams and Granara de Willink, Dysmicoccus texensis (Tinsley, Ferrisia cristinae Kaydan and Gullan, Ferrisia meridionalis Williams, Ferrisia terani Williams and Granara de Willink, Phenacoccus baccharidis Williams, Phenacoccus parvus Morrison, Phenacoccus solenopsis Tinsley, Planococcus citri (Risso, Pseudococcus viburni (Signoret, Pseudococcus cryptus Hempel, four taxa closely related each of to Pseudococcus viburni, Pseudococcus sociabilis Hambleton, Pseudococcus maritimus (Ehrhorn and Pseudococcus meridionalis Prado, and one specimen from the genus Pseudococcus Westwood. The PCR method developed effectively identified five mealybug species of economic interest on grape in Brazil: D. brevipes, Pl. citri, Ps. viburni, Ph. solenopsis and Planococcus ficus (Signoret. Nevertheless, it is not possible to assure that this procedure is reliable for taxa that have not been sampled already and might be very closely related to the target species.

  6. Molecular and morphological identification of mealybug species (Hemiptera: Pseudococcidae) in Brazilian vineyards.

    Science.gov (United States)

    Pacheco da Silva, Vitor C; Bertin, Aline; Blin, Aurélie; Germain, Jean-François; Bernardi, Daniel; Rignol, Guylène; Botton, Marcos; Malausa, Thibaut

    2014-01-01

    Mealybugs (Hemiptera: Pseudococcidae) are pests constraining the international trade of Brazilian table grapes. They damage grapes by transmitting viruses and toxins, causing defoliation, chlorosis, and vigor losses and favoring the development of sooty mold. Difficulties in mealybug identification remain an obstacle to the adequate management of these pests. In this study, our primary aim was to identify the principal mealybug species infesting the major table grape-producing regions in Brazil, by morphological and molecular characterization. Our secondary aim was to develop a rapid identification kit based on species-specific Polymerase Chain Reactions, to facilitate the routine identification of the most common pest species. We surveyed 40 sites infested with mealybugs and identified 17 species: Dysmicoccus brevipes (Cockerell), Dysmicoccus sylvarum Williams and Granara de Willink, Dysmicoccus texensis (Tinsley), Ferrisia cristinae Kaydan and Gullan, Ferrisia meridionalis Williams, Ferrisia terani Williams and Granara de Willink, Phenacoccus baccharidis Williams, Phenacoccus parvus Morrison, Phenacoccus solenopsis Tinsley, Planococcus citri (Risso), Pseudococcus viburni (Signoret), Pseudococcus cryptus Hempel, four taxa closely related each of to Pseudococcus viburni, Pseudococcus sociabilis Hambleton, Pseudococcus maritimus (Ehrhorn) and Pseudococcus meridionalis Prado, and one specimen from the genus Pseudococcus Westwood. The PCR method developed effectively identified five mealybug species of economic interest on grape in Brazil: D. brevipes, Pl. citri, Ps. viburni, Ph. solenopsis and Planococcus ficus (Signoret). Nevertheless, it is not possible to assure that this procedure is reliable for taxa that have not been sampled already and might be very closely related to the target species.

  7. Molecular evidence of polyandry in the citrus mealybug, Planococcus citri (Hemiptera: Pseudococcidae.

    Directory of Open Access Journals (Sweden)

    Sofia G Seabra

    Full Text Available The occurrence of polyandry in Planococcuscitri, presumed by earlier observations of mating behavior, was confirmed using microsatellite genotyping of pools of over 400 eggs resulting from controlled crosses of one female with two males. The genetic contribution of both mated males was confirmed in 13 out of 43 crosses. In three crosses it was possible to determine that only the first male fertilized the eggs, which may be due to sperm competition or unviable sperm supply. The microsatellite analysis also allowed the confirmation of aspects of the chromosomal inheritance detected previously in cytogenetic studies in Planococcuscitri, namely that only one of the alleles is transmitted by the male, indicating that the males are functionally haploid, supporting the observation of Paternal Genome Elimination (PGE in these insects.

  8. Molecular evidence of polyandry in the citrus mealybug, Planococcus citri (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Seabra, Sofia G; Brás, Patricia G; Zina, Vera; Borges da Silva, Elsa; Rebelo, Maria Teresa; Figueiredo, Elisabete; Mendel, Zvi; Paulo, Octávio S; Franco, José Carlos

    2013-01-01

    The occurrence of polyandry in Planococcuscitri, presumed by earlier observations of mating behavior, was confirmed using microsatellite genotyping of pools of over 400 eggs resulting from controlled crosses of one female with two males. The genetic contribution of both mated males was confirmed in 13 out of 43 crosses. In three crosses it was possible to determine that only the first male fertilized the eggs, which may be due to sperm competition or unviable sperm supply. The microsatellite analysis also allowed the confirmation of aspects of the chromosomal inheritance detected previously in cytogenetic studies in Planococcuscitri, namely that only one of the alleles is transmitted by the male, indicating that the males are functionally haploid, supporting the observation of Paternal Genome Elimination (PGE) in these insects.

  9. 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

  10. Non-host defense response in a novel Arabidopsis-Xanthomonas citri subsp. citri pathosystem.

    Directory of Open Access Journals (Sweden)

    Chuanfu An

    Full Text Available Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc, is one of the most destructive diseases of citrus. Progress of breeding citrus canker-resistant varieties is modest due to limited resistant germplasm resources and lack of candidate genes for genetic manipulation. The objective of this study is to establish a novel heterologous pathosystem between Xcc and the well-established model plant Arabidopsis thaliana for defense mechanism dissection and resistance gene identification. Our results indicate that Xcc bacteria neither grow nor decline in Arabidopsis, but induce multiple defense responses including callose deposition, reactive oxygen species and salicylic aicd (SA production, and defense gene expression, indicating that Xcc activates non-host resistance in Arabidopsis. Moreover, Xcc-induced defense gene expression is suppressed or attenuated in several well-characterized SA signaling mutants including eds1, pad4, eds5, sid2, and npr1. Interestingly, resistance to Xcc is compromised only in eds1, pad4, and eds5, but not in sid2 and npr1. However, combining sid2 and npr1 in the sid2npr1 double mutant compromises resistance to Xcc, suggesting genetic interactions likely exist between SID2 and NPR1 in the non-host resistance against Xcc in Arabidopsis. These results demonstrate that the SA signaling pathway plays a critical role in regulating non-host defense against Xcc in Arabidopsis and suggest that the SA signaling pathway genes may hold great potential for breeding citrus canker-resistant varieties through modern gene transfer technology.

  11. Proteome of the phytopathogen Xanthomonas citri subsp. citri: a global expression profile

    Directory of Open Access Journals (Sweden)

    Ferro Jesus A

    2010-11-01

    Full Text Available Abstract Background Citrus canker is a disease caused by Xantomonas citri subsp.citri (Xac, and has emerged as one of the major threats to the worldwide citrus crop because it affects all commercial citrus varieties, decreases the production and quality of the fruits and can spread rapidly in citrus growing areas. In this work, the first proteome of Xac was analyzed using two methodologies, two-dimensional liquid chromatography (2D LC and tandem mass spectrometry (MS/MS. Results In order to gain insight into the metabolism of Xac, cells were grown on two different media (NB - Nutrient Broth and TSE - Tryptone Sucrose broth enriched with glutamic acid, and proteins were proteolyzed with trypsin and examined by 2D LC-MS/MS. Approximately 39% of all predicted proteins by annotation of Xac were identified with their component peptides unambiguously assigned to tandem mass spectra. The proteins, about 1,100, were distributed in all annotated functional categories. Conclusions This is the first proteomic reference map for the most aggressive strain of Xanthomonas pathogen of all orange varieties. The compilation of metabolic pathways involved with bacterial growth showed that Xac expresses a complete central and intermediary metabolism, replication, transcription and translation machineries and regulation factors, distinct membrane transporters (ABC, MFS and pumps and receptors (MCP, TonB dependent and metabolites acquisition, two-component systems (sensor and regulatory components and response regulators. These data corroborate the growth curve in vitro and are the first reports indicating that many of these genome annotated genes are translated into operative in Xac. This proteomic analysis also provided information regarding the influence of culture medium on growth and protein expression of Xac.

  12. 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.

  13. 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.

    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. PMID:27609921

  14. The small and large subunits of carbamoyl-phosphate synthase exhibit diverse contributions to pathogenicity in Xanthomonas citri subsp. citri

    Institute of Scientific and Technical Information of China (English)

    Guo Jing; SonG Xue; Zou Li-fang; Zou Hua-song; CHen Gong-you

    2015-01-01

    Carbamoyl-phosphate synthase plays a vital role in the carbon and nitrogen metabolism cycles. In Xanthomonas citri subsp. citri, carA and carB encode the smal and large subunits of carbamoyl-phosphate synthase, respectively. The deletion mutation of the coding regions revealed that carA did not affect any of the phenotypes, while carB played multiple roles in pathogenicity. The deletion of carB rendered the loss of pathogenicity in host plants and the ability to induce a hyper-sensitive reaction in the non-hosts. Quantitative reverse transcription-PCR assays indicated that 11 hrp genes coding the type III secretion system were suppressed when interacting with citrus plants. The mutation in carB also affected bacterial utilization of several carbon and nitrogen resources in minimal medium MMX and extracel ular enzyme activities. These data demonstrated that only the large subunit of carbamoyl-phosphate synthase was essential for canker development by X. citri subsp. citri.

  15. Comparative ultrastructure of nonwounded Mexican lime and Yuzu leaves infected with the citrus canker bacterium Xanthomonas citri pv. citri.

    Science.gov (United States)

    Lee, In Jung; Kim, Ki Woo; Hyun, Jae Wook; Lee, Yong Hoon; Park, Eun Woo

    2009-07-01

    Ultrastructural aspects of citrus canker development were investigated in nonwounded leaves of citrus species by transmission electron microscopy (TEM). A susceptible species Mexican lime and a resistant species Yuzu were spray-inoculated with a virulent strain of Xanthomonas citri pv. citri. Initial symptoms occurred on Mexican lime approximately 9 days after inoculation, whereas they appeared on Yuzu mostly 11 days after inoculation. In Mexican lime leaves, the bacterial invasion was usually accompanied by host cell wall dissolution and cellular disruption. Fibrillar materials from degenerated cell walls were usually found in intercellular spaces. Damaged host cells with necrotic cytoplasm showed the localized separation of plasma membrane from the cell wall. Bacterial multiplication and electron-transparent capsule-like structures around bacteria were commonly observed. Meanwhile, cell wall protuberances were prominent outside host cell walls in response to bacterial invasion in Yuzu leaves. Occlusion of intercellular spaces was also formed by the fusion of two or more individual cell wall protuberances originated from two adjacent host cells. Papillae-like materials accumulated locally within host cells in close proximity to bacteria. Some bacteria were found to be undergoing degeneration in xylem vessels. Also, the shrunken, inactive bacteria were surrounded by electron-translucent fibrillar materials in intercellular spaces, implying bacterial immobilization. These cellular responses are thought to be the consequences of defense responses of Yuzu leaves to invading bacteria. In both citrus species, X. citri pv. citri contained polyphosphate bodies showing electron-dense and elliptical structures in cytoplasm.

  16. Preparation of Mealybugs (Hemiptera: Pseudococcidae) for Genetic Characterization and Morphological Examination.

    Science.gov (United States)

    Bahder, B W; Bollinger, M L; Sudarshana, M R; Zalom, F G

    2015-01-01

    Mealybugs (Hemiptera: Pseudococcidae) are economically significant agricultural pests on many different crops. Because of their small size and lack of easily visible characters for identification, determination of their taxonomic status is difficult and requires technical competency to prepare a slide-mounted specimen. The standard mounting technique does not allow for analysis of the genome of the specimen. Conversely, preparatory techniques for genetic analysis of mealybugs cause either loss of the entire individual or physical damage that can make morphology-based identification difficult. This study describes a simple protocol that does not impact physical integrity of the specimen for fixation and microscopic examination yet enables simultaneous DNA extraction for DNA-based identification of four mealybug species. All species prepared yielded high quality slide mounts, identified as Planococcus citri Risso, Pseudococcus viburni Signoret, Rhizoecus kondonis Kuwana, or Rhizoecus californicus Ferris. DNA extracted in this manner had higher purity and yield in the final eluate than in samples extracted using standard methods. DNA extracted was successfully amplified by polymerase chain reaction using primers for the cytochrome oxidase I gene and subsequently sequenced for all specimens. This protocol is likely to be applicable to other Hemiptera taxa that are preserved by slide mounting, allowing for both the preparation of a high-quality voucher specimen for morphological identification and simultaneous analysis of DNA for the same specimen. The methods used are technically less challenging than current standard procedures.

  17. Improved real-time PCR diagnosis of citrus stubborn disease by targeting prophage genes of Spiroplasma citri

    Science.gov (United States)

    Spiroplasma citri is a phloem-limited bacterium causing citrus stubborn disease (CSD). Isolation and culturing of S. citri is difficult and time consuming. Current detection methods use polymerase chain reaction (PCR) assays with primers developed from sequences of S. citri house-keeping genes. In c...

  18. 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.

  19. First report of citrus canker caused by Xanthomonas citri in Somalia

    Science.gov (United States)

    Xanthomonas citri, causal agent of citrus canker, has been reported in several countries in Africa, but not Somalia. During 2006 and 2007, hyperplasia-type lesions, often surrounded by a water-soaked margin and yellow halo, typical of citrus canker caused by X. citri, were found on 8-10 year-old gr...

  20. Comparison of Droplet Digital PCR and Quantitative PCR Assays for Quantitative Detection of Xanthomonas citri Subsp. citri.

    Directory of Open Access Journals (Sweden)

    Yun Zhao

    Full Text Available Droplet digital polymerase chain reaction (ddPCR is a novel molecular biology technique providing absolute quantification of target nucleic acids without the need for an external calibrator. Despite its emerging applications in medical diagnosis, there are few reports of its use for the detection of plant pathogens. This work was designed to assess the diagnosis potential of the ddPCR for absolute quantitative detection of Xanthomonas citri subsp. citri, a quarantine plant pathogenic bacterium that causes citrus bacterial canker in susceptible Citrus species. We transferred an established quantitative PCR (qPCR assay for citrus bacterial canker diagnosis directly to the ddPCR format and compared the performance of the two methods. The qPCR assay has a broader dynamic range compared to the ddPCR assay and the ddPCR assay has a significantly higher degree of sensitivity compared to the qPCR assay. The influence of PCR inhibitors can be reduced considerably in the ddPCR assay because the collection of end-point fluorescent signals and the counting of binomial events (positive or negative droplets are associated with a Poisson algorithm. The ddPCR assay also shows lower coefficient of variation compared to the qPCR assay especially in low target concentration. The linear association of the measurements by ddPCR and qPCR assays is strong (Pearson correlation = 0.8633; P<0.001. Receiver operating characteristic analysis indicates the ddPCR methodology is a more robust approach for diagnosis of citrus bacterial canker. In summary, the results demonstrated that the ddPCR assay has the potential for the quantitative detection of X. citri subsp. citri with high precision and accuracy as compared with the results from qPCR assay. Further studies are required to evaluate and validate the value of ddPCR technology in the diagnosis of plant disease and quarantine applications.

  1. 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.

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

    Science.gov (United States)

    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. PMID:28278188

  3. Acaricidal Activity of Boenninghausenia sessilicarpa Against Panonychus citri

    Institute of Scientific and Technical Information of China (English)

    YANG Hui-zhi; HU Jun-hua; LI Qing; LI Hong-jun; LIU Hao-qiang; YAO Ting-shan; RAN Chun; LEI Hui-de

    2009-01-01

    Acaricidal activity of Boenninghausenia sessilicarpa against Panonychus citri was tested in the laboratory.Four solvents were used to prepare crude extracts,petroleum ether,chloroform,ethyl acetate,and ethanol,among which ethanol was the most effective one.The results suggested that ethanol extracts of B.sessilicarpa had eminent acaricidal and ovicidal activities.Concentrated extracts were prepared using petroleum ether,chloroform,ethyl acetate,or distilled water as solvent.Mite mortality rates in the concentrated extracts by petroleum ether,chloroform,or distilled water were significantly lower than those by ethyl acetate.The LC50 values of eggs and female mites were 0.7639 and 1.1033 mg mL-1,respectively.After liquid chromatography and thin layer chromatography,the concentrated extracts were separated into 14 groups of fractions and further tests for their acaricidal and ovicidal activities were conducted.Fraction 2 was found to possess higher acaricidal and ovicidal activities.The mortality of eggs and adult mites were 85.83 and 63.07%,respectively.Moreover,fraction 2 showed moderate oviposition inhibition effect (0.8795) against P.citri when the used dose Was higher than 2.5 mg mL-1.

  4. Closely-related Xanthomonas citri subsp. citri isolates trigger distinct histological and transcriptional responses in Citrus limon

    Directory of Open Access Journals (Sweden)

    Ingrid Georgina Orce

    Full Text Available ABSTRACT Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc, has an important economic impact on the citrus industry. Extensive information is available about the disease but, nevertheless, the study of plant-pathogen interactions could provide new information in the understanding of citrus canker disease. A new isolate has been identified, Xcc AT, which has a high genetic similarity (> 90 % to the virulent Xcc T strain based on genetic clustering analyses of the rep-PCR fingerprinting patterns, but it does not produce cankerous lesions in Citrus limon. In this study, we compared C. limon responses to Xcc AT and to the virulent Xcc T strain at both histological and transcriptional levels. Histologically, leaves inoculated with Xcc AT exhibited neither a typical disordering of the spongy mesophyll, nor a swelling of epidermis. A particular content (undetermined was also found in mesophyll cells near the stomata, together with increased starch accumulation. The transcriptomic profiles were compared by cDNA-AFLP technique. A total of 121 fragments derived from transcript (TDF were either specifically induced or repressed by the isolates, and 62 were sequenced. Analysis of global expression identified different classes of genes known to be involved in plant-pathogen interactions. This study constitutes the first approach of the specific interaction between the avirulent Xcc AT isolate and C. limon.

  5. Effect of X-irradiation on Citrus Canker Pathogen Xanthomonas citri subsp. citri of Satsuma Mandarin Fruits

    Directory of Open Access Journals (Sweden)

    Min-A Song

    2015-12-01

    Full Text Available Citrus canker caused by Xanthomonas citri subsp. citri (Xcc is one of the most important bacterial diseases of citrus. Because citrus canker is not found in many countries including European Union and Australia, Xcc is strictly regulated in order to prevent its spread. In this study, the effects of X-irradiation on Xcc growth either in the suspension or on the surface of citrus fruits were investigated. The suspension containing 1×10⁷ cfu/ml of Xcc was irradiated with different absorbed doses of X-irradiation ranging from 50 to 400 Gy. The results showed that Xcc was fully dead at 400 Gy of X-irradiation. To determine the effect of X-irradiation on quarantine, the Xcc-inoculated citrus fruits were irradiated with different X-ray doses at which Xcc was completely inhibited by an irradiation dose of 250 Gy. The D₁₀ value for Xcc on citrus fruits was found to be 97 Gy, indicating the possibility of direct application on citrus quarantine without any side sterilizer. Beside, presence of Xcc on the surface of asymptomatic citrus fruits obtained from citrus canker-infected orchards was noted. It indicated that the exporting citrus fruits need any treatment so that Xcc on the citrus fruits should be completely eliminated. Based on these results, ionizing radiation can be considered as an alternative method of eradicating Xcc for export of citrus fruits.

  6. The role as inoculum sources of Xanthomonas citri pv. citri surviving on the infected Satsuma mandarin fruits.

    Science.gov (United States)

    Kang, So Young; Kim, Ki Deok; Hong, Jeum Kyu; Hyun, He Nam; Jeun, Yong Chull

    2014-05-01

    Importing citrus fruits infected by Asiatic citrus canker caused by Xanthomonas citri pv. citri (Xcc) can act as an inoculum source for the disease epidemic in citrus canker-free countries. In this study, the pathogenicity of the causal agent of Asiatic citrus canker surviving on infected Satsuma mandarin fruits was evaluated. The washing solution of infected Satsuma mandarin fruits did not cause lesion formation on the citrus leaves. However, a typical citrus canker lesion was formed on the leaves after inoculation with higher concentrations of the inoculum from the washing solution (washing solution II). It indicated that the pathogenicity of the citrus canker surviving on the symptomatic Satsuma mandarin fruits was not changed. Scanning electron microscopic observation showed that the numbers of bacterial cells on the leaves of Satsuma mandarin which inoculated with the washing solution directly (washing solution I) was less compared to those of leaves inoculated with the washing solution II. This result spports that the pathogenicity of Xcc surviving on Satsuma mandarin fruits may not be changed but that the sucessful infection of citrus caker may depend on the concentration of the inoculum.

  7. 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.

  8. Biology of Diaphorina citri (Homoptera: Psyllidae) on four host plants.

    Science.gov (United States)

    Tsai, J H; Liu, Y H

    2000-12-01

    The biology of the citrus psyllid Diaphorina citri Kuwayama was studied at 25 degrees C on four commonly grown citrus and related plants [rough lemon, Citrus jambhiri Lush; sour orange, C aurantium L.; grapefruit, C. paradisi Macfadyen; and orange jessamine, Murraya paniculata (L.) Jack] in the laboratory. The biological characteristics of each life stage are described. The average egg incubation periods on orange jessamine, grapefruit, rough lemon, and sour orange varied very little (4.1-4.2 d). The average nymphal developmental periods on these four host plants were essentially the same except the fifth stadium. Survival of immatures on orange jessamine, grapefruit, rough lemon, and sour orange was 75.4, 84.6, 78.3, and 68.6%, respectively. Female adults lived an average of 39.7, 39.7, 47.6, and 43.7 d on these respective host plants. The average number of eggs laid per female on grapefruit (858 eggs) was significantly more than those on other hosts (P < 0.05). The intrinsic rate of natural increase (r(m)) for D. citri on grapefruit was highest. Jackknife estimates of r(m) varied from 0.188 on grapefruit to 0.162 on orange jessamine and rough lemon. The mean population generation time on these hosts ranged from 31.6 to 34.1 d. The continuous flushes produced by orange jessamine could play an important role in maintaining high populations of this vector when the new flushes are not available in the commercial citrus groves.

  9. Citrus mealybug (Hemiptera: Pseudococcidae) movement and population dynamics in an arbor-trained vineyard.

    Science.gov (United States)

    Cid, M; Pereiro, S; Cabaleiro, C; Segura, A

    2010-06-01

    The citrus mealybug, Planococcus citri (Risso) (Hemiptera: Pseudococcidae), is the main grapevine pest in vineyards in some countries, such as Spain and Brazil. In Galician vineyards (northwestern Spain), mealybug population levels are low because the accumulated degree-days are lower than in other grapevine-growing areas. The main problem caused by mealybugs is the transmission of viruses, even at low infestation levels. The active period of citrus mealybug in the study vineyard lasted from July until December, with an important movement peak at the end of July and August and a lower peak in November. The mealybug mainly moved upward along arbor-trained plants, and there were no important downward movements at the end of the season as has been described for other grapevine mealybugs. The mealybugs were normally restricted to the woody organs and were only present on leaves, branches, and green canes (always close to woody parts) in plants with high infestations. The movement of mealybugs between plants does not seem to take place by contact between green organs. Passive aerial transport and movement of pruning remains may play an important role in mealybug movement and thus in spread of the virus. The number of mealybugs carrying Grapevine leafroll-associated virus 3 (GLRaV-3) was found to represent approximately 75% of mealybugs caught in a GLRaV-3 infected vineyard.

  10. A multiplex PCR assay for the simultaneous identification of three mealybug species (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Saccaggi, D L; Krüger, K; Pietersen, G

    2008-02-01

    Molecular species identification is becoming more wide-spread in diagnostics and ecological studies, particularly with regard to insects for which morphological identification is difficult or time-consuming. In this study, we describe the development and application of a single-step multiplex PCR for the identification of three mealybug species (Hemiptera: Pseudococcidae) associated with grapevine in South Africa: Planococcus ficus (vine mealybug), Planococcus citri (citrus mealybug) and Pseudococcus longispinus (longtailed mealybug). Mealybugs are pests on many commercial crops, including grapevine, in which they transmit viral diseases. Morphological identification of mealybug species is usually time-consuming, requires a high level of taxonomic expertise and usually only adult females can be identified. The single-step multiplex PCR developed here, based on the mitochondrial cytochrome c oxidase subunit 1 (CO I) gene, is rapid, reliable, sensitive, accurate and simple. The entire identification protocol (including DNA extraction, PCR and electrophoresis) can be completed in approximately four hours. Successful DNA extraction from laboratory and unparasitized field-collected individuals stored in absolute ethanol was 97%. Specimens from which DNA could be extracted were always correctly identified (100% accuracy). The technique developed is simple enough to be implemented in any molecular laboratory. The principles described here can be extended to any organism for which rapid, reliable identification is needed.

  11. Gender- and species-specific characteristics of bacteriomes from three psyllid species (Hemiptera: Psylloidae)

    Science.gov (United States)

    Psyllids (Hemiptera: Pyslloidea) harbor bacterial symbionts in specialized organs called bacteriomes. Bacteriomes may be subject to manipulation to control psyllid pests including Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) and Cacopsylla pyricola (Forster) (Hemiptera: Psyllidae) if the bi...

  12. [Analysis on medication rules of state medical master Yan Zhenghua from prescriptions with citri reticulatae pericarpium based on data mining].

    Science.gov (United States)

    Wu, Jia-Rui; Guo, Wei-Xian; Zhang, Bing; Zhang, Xiao-Meng; Yang, Bing; Sheng, Xiao-Guang

    2014-02-01

    The prescriptions containing pericarpium citri reticulatae that built by Professor. Yan were collected to build a database based on traditional Chinese medicine (TCM) inheritance assist system. After analyzed by data mining, such as apriori algorithm, the frequency of single medicine, the frequency of drug combination, the association rules between drugs and core drug combinations can be get from the database. Through the analysis of 1 027 prescriptions with pericarpium citri reticulatae, these prescriptions were commonly used to treat stomach aches, cough and other syndromes. The most frequency drug combinations were "Citri Reticulatae Pericarpium-Poria", "Paeoniae Radix Rubra-Citri Reticulatae Pericarpium" and so on. The drug association rules that the confidence was 1 were "Glycyrrhizae Radix ex Rhizoma --> Citri Reticulatae Pericarpium", "Paeoniae Alba Radix-Cyperi Rhizoma --> Citri Reticulatae Pericarpium", "Poria --> Citri Reticulatae Pericarpium", and so on. The drugs in the prescriptions containing pericarpium citri reticulatae that built by Professor Yan mostly had the effects of regulating the flow of Qi and invigorate blood circulation, which reflected the clearly thought when making prescriptions.

  13. 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...

  14. A Virulence-Reducing Mutation in the Postharvest Citrus Pathogen Alternaria citri.

    Science.gov (United States)

    Katoh, H; Isshiki, A; Masunaka, A; Yamamoto, H; Akimitsu, K

    2006-09-01

    ABSTRACT Alternaria citri causes Alternaria black rot, a postharvest fruit disease, on a broad range of citrus cultivars. We previously described that an endopolygalacturonase minus mutant of A. citri caused significantly less black rot in citrus fruit. To search for other essential factors causing symptoms in addition to endopolygalacturonase, a random mutation analysis of pathogenicity was performed using restriction enzyme-mediated integration. Three isolates among 1,694 transformants of A. citri had a loss in pathogenicity in a citrus peel assay, and one of these three mutants was a histidine auxotroph. Gene AcIGPD that encodes imidazole glycerol phosphate dehydratase, the sixth enzyme in the histidine biosynthetic pathway, was cloned, and the mutant containing the disrupted target gene, AcIGPD, caused less black rot.

  15. Stylet morphometrics and citrus leaf vein structure in relation to feeding behavior of the Asian citrus psyllid Diaphorina citri, vector of citrus huanglongbing bacterium.

    Science.gov (United States)

    Ammar, El-Desouky; Hall, David G; Shatters, Robert G

    2013-01-01

    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.

  16. 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...

  17. 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 doorgaan

  18. Reduced Susceptibility to Xanthomonas citri in Transgenic Citrus Expressing the FLS2 Receptor From Nicotiana benthamiana.

    Science.gov (United States)

    Hao, Guixia; Pitino, Marco; Duan, Yongping; Stover, Ed

    2016-02-01

    Overexpression of plant pattern-recognition receptors by genetic engineering provides a novel approach to enhance plant immunity and broad-spectrum disease resistance. Citrus canker disease associated with Xanthomonas citri is one of the most important diseases damaging citrus production worldwide. In this study, we cloned the FLS2 gene from Nicotiana benthamiana cDNA and inserted it into the binary vector pBinPlus/ARS to transform Hamlin sweet orange and Carrizo citrange. Transgene presence was confirmed by polymerase chain reaction (PCR) and gene expression of NbFLS2 was compared by reverse transcription quantitative PCR. Reactive oxygen species (ROS) production in response to flg22Xcc was detected in transgenic Hamlin but not in nontransformed controls. Low or no ROS production was detected from nontransformed Hamlin seedlings challenged with flg22Xcc. Transgenic plants highly expressing NbFLS2 were selected and were evaluated for resistance to canker incited by X. citri 3213. Our results showed that the integration and expression of the NbFLS2 gene in citrus can increase canker resistance and defense-associated gene expression when challenged with X. citri. These results suggest that canker-susceptible Citrus genotypes lack strong basal defense induced by X. citri flagellin and the resistance of these genotypes can be enhanced by transgenic expression of the flagellin receptor from a resistant species.

  19. Correlation of an electrical penetration graph waveform with walking by Asian citrus psyllid, Diaphorina citri Kuwayama

    Science.gov (United States)

    Electrical penetration graph (EPG) monitoring is being used to study how feeding behavior of the Asian citrus psyllid (ACP) (Diaphorina citri Kuwayama) changes in response to insecticides, in an effort to improve the efficacy of widespread insecticide treatments against the insect in Florida citrus....

  20. Perspectives to the use of entomopathogenic fungi for biological control of Diaphorina citri in Mexico

    OpenAIRE

    Sánchez-Peña, S. R.; Guizar-Guzmán, L.; Torres-Acosta, R. I.; López-Arroyo, J. I.; Casique-Valdés, R.

    2014-01-01

    Entomopathogenic fungi are natural enemies of D. citri adults in Mexico. Natural prevalence (%) of fungi on live adults in central Veracruz (summer) and southern Tamaulipas (fall) were: Hirsutella citriformis (7-35); Isaria fumosorosea (5-15); Lecanicillium (2 in Tamaulipas), and Beauveria (

  1. Molecular characterization of Wolbachia strains associated with the invasive Asian citrus psyllid Diaphorina citri in Brazil.

    Science.gov (United States)

    Guidolin, A S; Cônsoli, F L

    2013-02-01

    Wolbachia is a symbiont intensively studied due to its ability to interfere with their host's reproduction, and it has been recently proposed as an alternative tool to control insect pests or vectors of diseases. The Asian citrus psyllid Diaphorina citri is an important pest of citrus since it vectors the bacterium that causes the "Huanglongbing" disease in citrus. The frequency and diversity of Wolbachia associated with D. citri is unknown, limiting the utilization of Wolbachia as an alternative strategy for insect management. Thus, we aimed to determine the natural rate of infection, to characterize the Wolbachia strains associated with this psyllid by "multilocus sequencing typing" (MLST) and wsp analysis, and to verify the association of the symbiont to particular genotypes of the host. Analysis indicated Wolbachia infects 100 % of all specimens tested from all 15 sampled populations. MLST revealed the occurrence of five new sequence types (STs) of Wolbachia, while analysis based on the wsp sequences indicated only four different types of Wolbachia. ST-173 was predominant, while the remaining STs were population specific. Analysis of the host-symbiont relationship did not reveal any particular association of Wolbachia and haplotypes or a decrease in nucleotide diversity of D. citri in populations in which more than one ST was recorded. The consequences of the diversity of STs reported are still unknown, but the fact that Wolbachia infection is fixed and that there is one ST with a broad distribution highlights the use of this symbiont as an alternative strategy to control D. citri.

  2. Geïntegreerde bestrijding van citruswolluis Planococcus citri in roos

    NARCIS (Netherlands)

    Pijnakker, J.; Leman, A.; Staaij, van der M.

    2011-01-01

    Referaat Sinds begin 2000 is citruswolluis, Planococcus citri (Risso), een van de belangrijkste plagen geworden in de rozenteelt onder glas. Telers kiezen voor een meer geïntegreerde aanpak om andere plagen onder controle te houden en stoppen met het reguliere gebruik van breedwerkende middelen. Hie

  3. Low incidence of Candidatus Liberibacter asiaticus in Diaphorina citri and its host plant Murraya paniculata

    Science.gov (United States)

    Huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide. Candidatus Liberibacter asiaticus is the prevalent species of three HLB-associated Liberibacter species, which is vectored by the psyllid Diaphorina citri. The vector and the bacteria have host plants outside Citrus, ...

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

    Directory of Open Access Journals (Sweden)

    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

  5. Antifungal Effect of the Aqueous and Ethanolic Avicennia marina Extracts on Alternaria citri and Penicillium digitatum

    Directory of Open Access Journals (Sweden)

    Behrooz Alizadeh Behbahani

    2016-02-01

    Full Text Available Background Plants have a great potential for producing new drugs of great benefit to mankind. There are many approaches to the search for new biologically active principles in higher plants. Objectives The aim of this study was to determine antifungal effect of the aqueous and ethanolic extracts of Avicennia marina on Penicillium digitatum and Alternaria citri in vitro. Materials and Methods In this experimental study, antimicrobial effects of extract were determined by screening antimicrobial activity and disk agar diffusion test in 20, 40, 60 and 80 mg/mL concentration of the extract against P. digitatum and A. citri. Minimum inhibitory concentration (MIC and minimum fungicidal concentration (MFC were determined by incorporating various concentrations of extracts in Sabouraud dextrose agar (SDA in tubes against P. digitatum and A. citri. The data were analyzed using one way analysis of variance (ANOVA using SPSS-17. Results The results indicate that extracts of A. marina mostly had been effective on P. digitatum and have the least impact on A. citri. The results show that the ethanol extract of mangrove leaf with antimicrobial activity method in 2 mg/mL, were inhibited the growth of P. digitatum and A. citri. In disk agar diffusion test the mentioned extract were shown inhibition effect on pathogen molds growth (P < 0.05. Conclusions Ethanolic extract compared to the aqueous extract was more effective and has a greater inhibition effect. The results of this study showed that the extract of A. marina has antifungal properties that justify their traditional use as medicinal plants.

  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. Multimodal cues drive host-plant assessment in Asian citrus psyllid (Diaphorina citri).

    Science.gov (United States)

    Patt, Joseph M; Meikle, William G; Mafra-Neto, Agenor; Sétamou, Mamoudou; Mangan, Robert; Yang, Chenghai; Malik, Nasir; Adamczyk, John J

    2011-12-01

    Asian citrus psyllid (Diaphorina citri) transmits the causal agent of Huanglongbing, a devastating disease of citrus trees. In this study we measured behavioral responses of D. citri to combinations of visual, olfactory, and gustatory stimuli in test arenas. Stimuli were presented to the psyllids in droplets or lines of an emulsified wax formulation in two different arena types in no-choice tests. First, when placed on a colored ring situated halfway between the center and perimeter of a petri dish, D. citri spent more time on yellow versus gray rings; however, this response disappeared when either gray or yellow wax droplets were applied. When the psyllids were presented with droplets scented with terpenes, the response to both scent and color was increased. The addition of a dilute (≍0.1 M) sucrose solution to the wax droplets increased the magnitude of D. citri responses. Next, groups of D. citri were placed on plastic laboratory film covering a sucrose solution, to mimic a leaf surface. Test stimuli were presented via two 'midribs' made from lines of emulsified wax formulation. Probing levels were measured as a function of color saturation and scent composition, and concentration. The test scents were based on qualitatively major volatiles emitted by Murraya paniculata (L.) Jack, Citrus aurantifolia (Christm.) Swingle, and C. sinensis (L.) Osbeck. The highest probing response was observed on the middle concentration (20-μl scent/10 ml wax formulation) of the C. aurantifolia-scented wax lines. Results indicate that there are interactive effects between the different sensory modalities in directing host-plant assessment behavior.

  8. Expressão gênica diferencial de laranja Pêra Rio (Citrus sinensis (L.) Osbeck) e Lima Ácida 'Galego' (Citrus aurantifolia Swingle) em resposta à infecção por Xanthomonas citri subsp. citri

    OpenAIRE

    Cavallini, Juliana da Silva [UNESP

    2013-01-01

    The citrus agribusiness is very important to the Brazilian economy, but the increase of diseases in the last decade has caused great economic losses to the sector. The citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xac), is a serious disease that attacks all citrus species economically important worldwide and there is not an effective method for its control. In this study, RNASeq was used to analyze the transcriptional profiles of two contrasting citrus genotypes regar...

  9. Endosymbiont hunting in the metagenome of Asian citrus psyllid (Diaphorina citri) (7th Annual SFAF Meeting, 2012)

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Surya [Cornell University

    2012-06-01

    Surya Saha on "Endosymbiont hunting in the metagenome of Asian citrus psyllid (Diaphorina citri)" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.

  10. Green Fluorescent Detection of Fungal Colonization and Endopolygalacturonase Gene Expression in the Interaction of Alternaria citri with Citrus.

    Science.gov (United States)

    Isshiki, A; Ohtani, K; Kyo, M; Yamamoto, H; Akimitsu, K

    2003-07-01

    ABSTRACT Alternaria citri, a postharvest pathogen, produces endopolygalacturonase (endoPG) and causes black rot on citrus fruit. We previously described that an endoPG-disrupted mutant of Alternaria citri was significantly reduced in its ability to macerate plant tissue and cause black rot symptoms on citrus. In order to investigate colonization of citrus fruit tissues by Alternaria citri, pTEFEGFP carrying a green fluorescent protein (GFP) gene was introduced into wild-type Alternaria citri and its endoPG-disrupted mutant (M60). Green fluorescence was observed in spores, germ tubes, appressoria, and infection hyphae of transformants G1 (derived from wild type) and GM4 (derived from M60). Hyphae of G1 but not GM4 vertically penetrated the peel, but the hyphae of both G1 and GM4 spread equally in the juice sac area of citrus fruit. Green fluorescence of Alternaria citri transformant EPG7 carrying a GFP gene under control of the endoPG gene promoter of Alternaria citri was induced by pectin in the peel during the infection stage, but repressed completely in the juice sac area, likely by carbon catabolite repression by sugars in the juice.

  11. Novel diagnosis for citrus stubborn disease by detection of a spiroplasma citri-secreted protein.

    Science.gov (United States)

    Shi, Jinxia; Pagliaccia, Deborah; Morgan, Robyn; Qiao, Yongli; Pan, Songqin; Vidalakis, Georgios; Ma, Wenbo

    2014-02-01

    Citrus stubborn disease (CSD), first identified in California, is a widespread bacterial disease found in most arid citrus-producing regions in the United States and the Mediterranean Region. The disease is caused by Spiroplasma citri, an insect-transmitted and phloem-colonizing bacterium. CSD causes significant tree damage resulting in loss of fruit production and quality. Detection of CSD is challenging due to low and fluctuating titer and sporadic distribution of the pathogen in infected trees. In this study, we report the development of a novel diagnostic method for CSD using an S. citri-secreted protein as the detection marker. Microbial pathogens secrete a variety of proteins during infection that can potentially disperse systemically in infected plants with the vascular flow. Therefore, their distribution may not be restricted to the pathogen infection sites and could be used as a biological marker for infection. Using mass spectrometry analysis, we identified a unique secreted protein from S. citri that is highly expressed in the presence of citrus phloem extract. ScCCPP1, an antibody generated against this protein, was able to distinguish S. citri-infected citrus and periwinkle from healthy plants. In addition, the antiserum could be used to detect CSD using a simple direct tissue print assay without the need for sample processing or specialized lab equipment and may be suitable for field surveys. This study provides proof of a novel concept of using pathogen-secreted protein as a marker for diagnosis of a citrus bacterial disease and can probably be applied to other plant diseases.

  12. 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)

  13. Seasonal Population Dynamics of the Asian Citrus Psyllid, Diaphorina citri Kuwayama in Sarawak

    Directory of Open Access Journals (Sweden)

    Stephen L.C. Teck

    2011-01-01

    Full Text Available Problem statement: Effective control of phytophagous pests requires a thorough understanding of their seasonal population dynamics, dispersion behavior, natural enemy activity and climate. To date, although very little detail information had been published on the ecology of Diaphorina citri. The objective of this investigation was to test through field experiment the hypothesis that the major factors influencing local D. citri populations particularly their seasonal population dynamics in Sarawak are (a flushing cycles, (b climate and (c the impact of the primary parasitoids namely Tamarixia radiata and Diaphorencyrtus aligarhensis. Approach: Seasonal abundance D. citri was studied weekly from March 1998 to December 2000 in the 1-ha citrus honey mandarin (Citrus aurantium L. commercial orchard at Jemukan (1° 33'N, 110° 41'E, Kota Samarahan Division, Southwest Sarawak, in Malaysia. Results: Field studies on citrus trees showed that the D. citri population fluctuates throughout the year on citrus honey mandarin in Sarawak. Generations overlapped but adult and egg population peaks for a short period generally coincided with three annual flushing cycles, in August-September, February-March and June-July between March 1998 and December 2000. Conclusion: Psyllid population levels are positively related to the availability of new shoot flushes. Psyllid populations are adversely affected by weather conditions and parasitoids. Adult psyllid populations increased exponentially during periods of flush growth and migration and dispersal of the adults was also related to flushing cycles. Dispersal and colonization of new trees is greatest in September-October, at the onset of the rainy season.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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.

  17. Xanthomonas citri subsp. citri surface proteome by 2D-DIGE: Ferric enterobactin receptor and other outer membrane proteins potentially involved in citric host interaction.

    Science.gov (United States)

    Carnielli, Carolina Moretto; Artier, Juliana; de Oliveira, Julio Cezar Franco; Novo-Mansur, Maria Teresa Marques

    2017-01-16

    Xanthomonas citri subsp. citri (XAC) is the causative agent of citrus canker, a disease of great economic impact around the world. Understanding the role of proteins on XAC cellular surface can provide new insights on pathogen-plant interaction. Surface proteome was performed in XAC grown in vivo (infectious) and in vitro (non-infectious) conditions, by labeling intact cells followed by cellular lysis and direct 2D-DIGE analysis. Seventy-nine differential spots were analyzed by mass spectrometry. Highest relative abundance for in vivo condition was observed for spots containing DnaK protein, 60kDa chaperonin, conserved hypothetical proteins, malate dehydrogenase, phosphomannose isomerase, and ferric enterobactin receptors. Elongation factor Tu, OmpA-related proteins, Oar proteins and some Ton-B dependent receptors were found in spots decreased in vivo. Some proteins identified on XAC's surface in infectious condition and predicted to be cytoplasmic, such as DnaK and 60KDa chaperonin, have also been previously found at cellular surface in other microorganisms. This is the first study on XAC surface proteome and results point to mediation of molecular chaperones in XAC-citrus interaction. The approach utilized here can be applied to other pathogen-host interaction systems and help to achieve new insights in bacterial pathogenicity toward promising targets of biotechnological interest.

  18. Potential of South African entomopathogenic nematodes (Heterorhabditidae and Steinernematidae) for control of the citrus mealybug, Planococcus citri (Pseudococcidae).

    Science.gov (United States)

    van Niekerk, Sonnica; Malan, Antoinette P

    2012-10-01

    Planococcus citri, the citrus mealybug, is the most important species of mealybug known to infest citrus in South Africa. Various laboratory bioassays were conducted to determine the potential of entomopathogenic nematodes to control P. citri. Adult female P. citri were screened for susceptibility to six indigenous nematode species. P. citri was found to be most susceptible to Steinernema yirgalemense and Heterorhabditis zealandica, causing 97% and 91% mortality, respectively. The development of nematodes after infecting adult female P. citri showed both H. zealandica and S. yirgalemense were able to complete their life cycles inside the host. Further bioassays illustrated a linear relationship between mealybug mortality and the concentration of nematodes applied, with the highest level of control using a concentration of 80 infective juveniles (IJs)/insect. As nematodes would be used as an above-ground application to control P. citri in citrus orchards, available water is a major limiting factor. Insecticidal activity proved to be dependent on the available surface moisture after nematode application. The water activity (a(w)) bioassay indicated that S. yirgalemense to be two times more tolerant to lower levels of free water, with a(w50)=0.96 and a(w90)=0.99, compared to H. zealandica with a(w50)=0.98 and a(w)90=1.0. After application, nematodes have a limited time frame in which to locate and infect hosts, as the level of available free water gradually decreases, as trees dry out. S. yirgalemense proved able to locate and infect P. citri quicker than H. zealandica. Nematode activity was not significantly affected when exposed to 15°C, 20°C and 25°C. IJs were able to infect P. citri at an exposure time as short as half an hour. Results also showed that the first 2-4h post application is the most decisive time for establishing successful infection of mealybugs. This is the first report on the potential use of nematodes for the control of P. citri.

  19. Analyses of Numerical Responses and Main Life Parameters for Determining the Suppression of Amblyseius cucumeris on Panonychus citri

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan-xuan; LIN Jian-zhen; JI Jie; CHEN Xie; KANG Yu-mei

    2005-01-01

    In this paper, the numeral response and main parameters of experimental population life table were analyzed for determiningthe suppressing ability of Amblyseius cucumeris on Panonychus citri. The result showed that: (1) Under 21-31 ℃ and 1-9 prey densities/leaf fragment condition, the prey consumptions ofA. cucumeris increased with the temperature or prey density; (2) In 1:3 predator-prey ratio treatment, the suppression ofP. citri (Ro=34.0053; T=19.4369; t=3.8204) was rather weak, it was enhanced as the ratio over 5:30, and the populations ofP. citri in these treatments can be fully controlled within 4-5 days; (3) Under 25±1℃, 80-85% RH and 15L: 9D illumination conditions, the net reproductive rate, mean generation duration and the time for population double increase ofP. citri (Ro=34.0053; T=19.4369; t=3.8204) were higher than those ofA. cucumeris (Ro=21.8750; T=16.8943; t=3.7954). While the intrinsic rate of increase and finite rate of increase of the former (rm=0.1814; λ= 1.1989) were lower than those of the latter (rm=0.1826; λ= 1.2004). These results indicated that A. cucumeris is a desirable bio-control agent to suppress P. citri at lower population stage in citrus orchard.

  20. Expression patterns of genes involved in the defense and stress response of Spiroplasma citri infected Madagascar Periwinkle Catharanthus roseus.

    Science.gov (United States)

    Nejat, Naghmeh; Vadamalai, Ganesan; Dickinson, Matthew

    2012-01-01

    Madagascar periwinkle is an ornamental and a medicinal plant, and is also an indicator plant that is highly susceptible to phytoplasma and spiroplasma infections from different crops. Periwinkle lethal yellows, caused by Spiroplasma citri, is one of the most devastating diseases of periwinkle. The response of plants to S. citri infection is very little known at the transcriptome level. In this study, quantitative real-time PCR (RT-qPCR) was used to investigate the expression levels of four selected genes involved in defense and stress responses in naturally and experimentally Spiroplasma citri infected periwinkles. Strictosidine β-glucosidase involved in terpenoid indole alkaloids (TIAs) biosynthesis pathway showed significant upregulation in experimentally and naturally infected periwinkles. The transcript level of extensin increased in leaves of periwinkles experimentally infected by S. citri in comparison to healthy ones. A similar level of heat shock protein 90 and metallothionein expression was observed in healthy, naturally and experimentally spiroplasma-diseased periwinkles. Overexpression of Strictosidine β-glucosidase demonstrates the potential utility of this gene as a host biomarker to increase the fidelity of S. citri detection and can also be used in breeding programs to develop stable disease-resistance varieties.

  1. Expression Patterns of Genes Involved in the Defense and Stress Response of Spiroplasma citri Infected Madagascar Periwinkle Catharanthus roseus

    Directory of Open Access Journals (Sweden)

    Naghmeh Nejat

    2012-02-01

    Full Text Available Madagascar periwinkle is an ornamental and a medicinal plant, and is also an indicator plant that is highly susceptible to phytoplasma and spiroplasma infections from different crops. Periwinkle lethal yellows, caused by Spiroplasma citri, is one of the most devastating diseases of periwinkle. The response of plants to S. citri infection is very little known at the transcriptome level. In this study, quantitative real-time PCR (RT-qPCR was used to investigate the expression levels of four selected genes involved in defense and stress responses in naturally and experimentally Spiroplasma citri infected periwinkles. Strictosidine β-glucosidase involved in terpenoid indole alkaloids (TIAs biosynthesis pathway showed significant upregulation in experimentally and naturally infected periwinkles. The transcript level of extensin increased in leaves of periwinkles experimentally infected by S. citri in comparison to healthy ones. A similar level of heat shock protein 90 and metallothionein expression was observed in healthy, naturally and experimentally spiroplasma-diseased periwinkles. Overexpression of Strictosidine β-glucosidase demonstrates the potential utility of this gene as a host biomarker to increase the fidelity of S. citri detection and can also be used in breeding programs to develop stable disease-resistance varieties.

  2. Establishment of EMA-PCR detection method of viable cells of Xanthomonas citri subsp.citri%柑橘溃疡病菌EMA-PCR快速活体检测技术的建立

    Institute of Scientific and Technical Information of China (English)

    熊书; 王中康; 卢小林; 殷幼平

    2013-01-01

    传统PCR方法不能诊断柑橘溃疡病菌(Xanthomonas citri subsp.citri Gabriel)的死活状态,往往导致假阳性检测结果.本研究将特异性核酸染料叠氮溴化乙锭(ethidium monoazide bromide,EMA)与PCR技术结合,旨在建立柑橘溃疡病活菌的快速检测技术.根据柑橘溃疡病菌独有的保守蛋白基因设计特异性引物扩增出278 bp的靶带,PCR反应的检测下限为25个细胞/25 μL或2.75 pg/25 μL.EMA-PCR结果表明:当卤钨灯曝光时间1 min,EMA终浓度为1.0 mg/L时,能有效抑制1.0×108 cfu/mL死菌的扩增;当EMA的浓度小于30 mg/L时,EMA对上述相同浓度活菌靶基因的扩增没有明显的抑制.EMA-PCR对死活混合菌的扩增表明,活菌数在6.875×101~6.875×105 cfu/PCR范围时,荧光强度与混合体系中活菌的对数值有线性关系.基于以上建立的EMA-PCR活体检测技术,对疑似带病柑橘材料进行检测,结果发现能降低柑橘溃疡病菌检测过程中的假阳性,有望为柑橘溃疡病的检疫检验提供更科学的技术手段.%Conventional PCR method can not distinguish live cells from dead cells of Xanthononas citri subsp.citri Gabriel,and false positives results can easily be obtained in detection process.Ethidium monoazide bromide (EMA) can selectively inhibit PCR amplification of DNA from dead cells.Therefore,in this study,EMA was combined with PCR to detect viable cells of X.citri subsp.citri.Firstly,primers (Xcc R/Xcc F) specific to X.citri subsp.citri were designed to amplify a 278 bp fragment.The minimum limit of detection was 25 cells/25 μL PCR volume or 2.75 pg/25 μ L PCR volume.The results of EMA-PCR showed that the optimized light exposure time was at least 1 min,allowing crosslinking of DNA by the EMA in dead cells and photolysing the free EMA in solution.The minimum amount of EMA to completely inhibit the PCR amplification of DNA derived from heat-killed cells was 1.0 mg/L.EMA less than 30 mg/L did not inhibit the PCR amplification

  3. Paternal inheritance in mealybugs (Hemiptera: Coccoidea: Pseudococcidae).

    Science.gov (United States)

    Kol-Maimon, Hofit; Mendel, Zvi; Franco, José Carlos; Ghanim, Murad

    2014-10-01

    Mealybugs have a haplodiploid reproduction system, with paternal genome elimination (PGE); the males are diploid soon after fertilization, but during embryogenesis, the male paternal set of chromosomes becomes heterochromatic (HC) and therefore inactive. Previous studies have suggested that paternal genes can be passed on from mealybug males to their sons, but not necessarily by any son, to the next generation. We employed crosses between two mealybug species--Planococcus ficus (Signoret) and Planococcus citri (Risso)--and between two populations of P. ficus, which differ in their mode of pheromone attraction, in order to demonstrate paternal inheritance from males to F2 through F1 male hybrids. Two traits were monitored through three generations: mode of male pheromone attraction (pherotype) and sequences of the internal transcribed spacer 2 (ITS2) gene segment (genotype). Our results demonstrate that paternal inheritance in mealybugs can occur from males to their F2 offspring, through F1 males (paternal line). F2 backcrossed hybrid males expressed paternal pherotypes and ITS2 genotypes although their mother originated through a maternal population. Further results revealed other, hitherto unknown, aspects of inheritance in mealybugs, such as that hybridization between the two species caused absence of paternal traits in F2 hybrid females produced by F1 hybrid females. Furthermore, hybridization between the two species raised the question of whether unattracted males have any role in the interactions between P. ficus and P. citri.

  4. 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.

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

    Science.gov (United States)

    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.

    2017-01-01

    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. PMID:28386418

  6. Structural and Physiological Analyses of the Alkanesulphonate-Binding Protein (SsuA) of the Citrus Pathogen Xanthomonas citri

    Science.gov (United States)

    Tófoli de Araújo, Fabiano; Bolanos-Garcia, Victor M.; Pereira, Cristiane T.; Sanches, Mario; Oshiro, Elisa E.; Ferreira, Rita C. C.; Chigardze, Dimitri Y.; Barbosa, João Alexandre Gonçalves; de Souza Ferreira, Luís Carlos; Benedetti, Celso E.; Blundell, Tom L.; Balan, Andrea

    2013-01-01

    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. PMID:24282519

  7. 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.

  8. The abundant extrachromosomal DNA content of the Spiroplasma citri GII3-3X genome

    Directory of Open Access Journals (Sweden)

    Carrère Sébastien

    2008-04-01

    Full Text Available Abstract Background Spiroplama citri, the causal agent of citrus stubborn disease, is a bacterium of the class Mollicutes and is transmitted by phloem-feeding leafhopper vectors. In order to characterize candidate genes potentially involved in spiroplasma transmission and pathogenicity, the genome of S. citri strain GII3-3X is currently being deciphered. Results Assembling 20,000 sequencing reads generated seven circular contigs, none of which fit the 1.8 Mb chromosome map or carried chromosomal markers. These contigs correspond to seven plasmids: pSci1 to pSci6, with sizes ranging from 12.9 to 35.3 kbp and pSciA of 7.8 kbp. Plasmids pSci were detected as multiple copies in strain GII3-3X. Plasmid copy numbers of pSci1-6, as deduced from sequencing coverage, were estimated at 10 to 14 copies per spiroplasma cell, representing 1.6 Mb of extrachromosomal DNA. Genes encoding proteins of the TrsE-TraE, Mob, TraD-TraG, and Soj-ParA protein families were predicted in most of the pSci sequences, in addition to members of 14 protein families of unknown function. Plasmid pSci6 encodes protein P32, a marker of insect transmissibility. Plasmids pSci1-5 code for eight different S. citri adhesion-related proteins (ScARPs that are homologous to the previously described protein P89 and the S. kunkelii SkARP1. Conserved signal peptides and C-terminal transmembrane alpha helices were predicted in all ScARPs. The predicted surface-exposed N-terminal region possesses the following elements: (i 6 to 8 repeats of 39 to 42 amino acids each (sarpin repeats, (ii a central conserved region of 330 amino acids followed by (iii a more variable domain of about 110 amino acids. The C-terminus, predicted to be cytoplasmic, consists of a 27 amino acid stretch enriched in arginine and lysine (KR and an optional 23 amino acid stretch enriched in lysine, aspartate and glutamate (KDE. Plasmids pSci mainly present a linear increase of cumulative GC skew except in regions presenting

  9. 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

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

    Science.gov (United States)

    Shen, Xiao-Min; Liao, Chong-Yu; Lu, Xue-Ping; Wang, Zhe; Wang, Jin-Jun; Dou, Wei

    2016-08-19

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Responsiveness of different citrus genotypes to the Xanthomonas citri ssp. citri-derived pathogen-associated molecular pattern (PAMP) flg22 correlates with resistance to citrus canker.

    Science.gov (United States)

    Shi, Qingchun; Febres, Vicente J; Jones, Jeffrey B; Moore, Gloria A

    2015-06-01

    The bacterial agent of citrus canker disease (Xanthomonas citri ssp. citri, Xcc) has caused tremendous economic losses to the citrus industry around the world. Pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) is important to plant immunity. In this study, we compared the defence responses of citrus canker-resistant and citrus canker-susceptible genotypes to the Xcc-derived PAMP flg22 (Xflg22) by analysing the expression of 20 citrus defence-associated genes. We showed that, in the most resistant genotype, 'Nagami' kumquat, there was significant induction of several defence genes (EDS1, NDR1, PBS1, RAR1, SGT1, PAL1, NPR2 and NPR3) as early as 6 h and up to 72 h after Xflg22 treatment. At the other end of the spectrum, highly susceptible 'Duncan' grapefruit showed no induction of the same defence genes, even 120 h after treatment. Citrus genotypes with partial levels of resistance showed intermediate levels of transcriptional reprogramming that correlated with their resistance level. Xflg22 also triggered a rapid oxidative burst in all genotypes which was higher and accompanied by the induction of PTI marker genes (WRKY22 and GST1) only in the more resistant genotypes. Pretreatment with Xflg22 prior to Xcc inoculation inhibited bacterial growth in kumquat, but not in grapefruit. A flagellin-deficient Xcc strain (XccΔfliC) showed greater growth increase relative to wild-type Xcc in kumquat than in grapefruit. Taken together, our results indicate that Xflg22 initiates strong PTI in canker-resistant genotypes, but not in susceptible ones, and that a robust induction of PTI is an important component of citrus resistance to canker.

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

    Science.gov (United States)

    Piazza, Ainelén; Zimaro, Tamara; Garavaglia, Betiana S; Ficarra, Florencia A; Thomas, Ludivine; Marondedze, Claudius; Feil, Regina; Lunn, John E; Gehring, Chris; Ottado, Jorgelina; Gottig, Natalia

    2015-05-01

    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.

  14. 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.

  15. 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

  16. Toxicity of insecticidal soaps to the Asian citrus psyllid (Diaphorina citri) and two of its natural enemies

    Science.gov (United States)

    Insecticidal soaps (hereafter “soaps”) are labeled for use by homeowners and also can be used in citrus grown for the organic market. Soaps control some insect pests and therefore might be an alternative to conventional pesticides for control of the Asian citrus psyllid, Diaphorina citri Kuwayama (...

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

    Energy Technology Data Exchange (ETDEWEB)

    Faria, J.N.; Balan, A. [Laboratorio Nacional de Biociencias - LNBIO, Campinas, SP (Brazil); Paes Leme, A.F. [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil)

    2012-07-01

    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)

  18. Species limits in Diaporthe: molecular re-assessment of D. citri, D. cytosporella, D. foeniculina and D. rudis

    NARCIS (Netherlands)

    Udayanga, D.; Castlebury, L.A.; Rossman, A.Y.; Hyde, K.D.

    2014-01-01

    Species of Diaporthe are important plant pathogens of a wide range of hosts worldwide. In the present study the species causing melanose and stem end rot diseases of Citrus spp. are revised. Three species of Diaporthe occurring on Citrus are characterised, including D. citri, D. cytosporella and D.

  19. Complete genome sequence of Spiroplasma citri strain R8-A2T, causal agent of stubborn disease in Citrus spp.

    Science.gov (United States)

    Spiroplasma citri is the causal agent of stubborn disease in Citrus spp., as well as the cause of diseases in numerous other plant genera. Here we report the nucleotide sequence of the 1,599,709 bp circular chromosome and two plasmids of strain R8-A2T. This information will facilitate comparative ...

  20. Identification of differentially expressed genes of Xanthomonas axonopodis pv. citri by representational difference analysis of cDNA

    Directory of Open Access Journals (Sweden)

    Angela Mehta

    2005-03-01

    Full Text Available Xanthomonas axonopodis pv. citri is a phytopathogenic bacterium responsible for citrus canker, a serious disease which causes severe losses in citriculture around the world. In this study we report the differential expression of X. axonopodis pv. citri in response to specific treatments by using Representational Difference Analysis of cDNA (cDNA RDA. cDNAs from X. axonopodis pv. citri cultured in the presence of leaf extract of the host plant (Citrus sinensis, in vivo, as well as in the complex medium were hybridized against cDNA of the bacterium grown in the minimal medium. Sequencing of the difference products obtained after the second and third hybridizations revealed a total of 37 distinct genes identified by homology searches in the genome of X. axonopodis pv. citri. These genes were distributed in different functional categories, including genes that encode hypothetical proteins, genes involved in metabolism, cellular processes and pathogenicity, and mobile genetic elements. Most of these genes are likely related to growth and/or acquisition of nutrients in specific treatments whereas others might be important for the bacterium pathogenicity.

  1. Identification and Characterization of Seven Glutathione S-Transferase Genes from Citrus Red Mite, Panonychus citri (McGregor

    Directory of Open Access Journals (Sweden)

    Chong-Yu Liao

    2013-12-01

    Full Text Available The citrus red mite, Panonychus citri (McGregor, is a global citrus pest, and has developed severe resistance to several types of acaricides. However, the molecular mechanisms of resistance in this mite remain unknown. In this study, seven full-length cDNAs encoding glutathione S-transferases (GSTs genes were identified and characterized in P. citri. The effects of pyridaben and fenpropathrin exposure on the expression of these genes were also investigated. Phylogenetic analysis revealed that the seven GSTs genes in P. citri cloned in this study belong to three different cytosolic classes, including four in mu, two in delta and one in zeta. Among these seven GSTs genes, the relative expression level of PcGSTm1 was significantly higher in adult than in the other life stages (egg, larvae and nymph. Compared with the control, the mRNA levels of the seven GST genes did not change significantly following exposure to pyridaben at LC10. However, RT-qPCR results showed that, when exposed to LC10 of fenpropathrin, six GSTs gene (PcGSTm1, PcGSTm3, PcGSTm4, PcGSTd1, PcGSTd2 and PcGSTz1 transcripts increased in a time-dependent manner. This is the first insight into the molecular characteristics of GSTs gene cDNAs in P. citri. The elevated GSTs gene transcripts following exposure to fenpropathrin might be one of the mechanisms involved in detoxification of this acaricide.

  2. Influence of Host Plant Species and Flush Growth Stage on the Asian Citrus Psyllid, Diaphorina citri Kuwayama

    Directory of Open Access Journals (Sweden)

    Stephen L.C. Teck

    2011-01-01

    Full Text Available Problem statement: In order to establish the important host range of D. citri, the performance of this psyllid on different rutacous host plants was assessed. Apparent regional differences in host preferences of D. citri as noted above and the need for empirical knowledge of its host preferences in Malaysia where it is lacking. Approach: Experiments on host plant preference between citrus, jasmine orange and curry leaf were conducted over a period of 14 days in the field cage in October 1998 at the agricultural research centre, Semonggok, 15 km from Kuching, Kuching Division, Sarawak in Malaysia. Results: A comparative life cycle study of the Asian Citrus Psyllid Diaphorina citri Kuwayama on three different Rutaceous plant hosts namely citrus, jasmine orange and curry leaf plants was conducted inside the temperature controlled growth chamber maintain at 26 ± 1°C temperature, 75-80% relative humidity with artificial illumination intensity of 10,000 lux equipped with a photoperiod of 14:10 h light: dark regime to permit normal growth. Conclusion: The screenhouse studies confirmed that D. citri can colonise and breed on citrus, jasmine orange and curry leaf plant and that jasmine orange is the preferred host. It is also confirmed that females prefer to oviposit on immature flush 3-10 mm in length. In growth chamber experiments the life cycle of the psyllid was 18.5 days on jasmine orange, 19.0 days on citrus and 23.0 days on curry leaf.

  3. Development and reproduction of Panonychus citri (Prostigmata: Tetranychidae) on different species and varieties of citrus plants.

    Science.gov (United States)

    Zanardi, Odimar Zanuzo; Bordini, Gabriela Pavan; Franco, Aline Aparecida; de Morais, Matheus Rovere; Yamamoto, Pedro Takao

    2015-12-01

    The species and varieties of citrus plants that are currently grown can favor the population growth of the citrus red mite Panonychus citri (McGregor) (Prostigmata: Tetranychidae) and alter the pest management programs in citrus groves. In this study we evaluated, in the laboratory, the development and reproduction of P. citri and estimated its life table parameters when reared on four varieties of Citrus sinensis (L.) Osbeck (Valencia, Pera, Natal, and Hamlin), one variety of Citrus reticulata Blanco (Ponkan) and one variety of Citrus limon (L.) Burm. (Sicilian). The incubation period and egg viability were not affected by the host plant. However, the development and survival of the immature stage were significantly lower on Hamlin orange than on Valencia, Pera and Natal oranges, Ponkan mandarin and Sicilian lemon. The fecundity and oviposition period of females were lower on Hamlin orange than on the other hosts. Mites reared on Valencia orange and Sicilian lemon had a higher net reproductive rate (R 0 ), intrinsic growth rate (r) and finite rate of increase (λ), and a shorter interval between generations (T) than on Pera, Natal and Hamlin oranges and Ponkan mandarin. On the other hand, mites reared on Hamlin orange had the lowest R 0 , r and λ and the highest T among the hosts. Based on the results obtained we recommend that for Valencia orange and Sicilian lemon, the mite monitoring programs should be more intense to detect the initial infestation of pest, avoiding the damage in plants and the increase in production costs.

  4. 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)

  5. A novel two-component response regulator links rpf with biofilm formation and virulence of Xanthomonas axonopodis pv. citri.

    Directory of Open Access Journals (Sweden)

    Tzu-Pi Huang

    Full Text Available Citrus bacterial canker caused by Xanthomonas axonopodis pv. citri is a serious disease that impacts citrus production worldwide, and X. axonopodis pv. citri is listed as a quarantine pest in certain countries. Biofilm formation is important for the successful development of a pathogenic relationship between various bacteria and their host(s. To understand the mechanisms of biofilm formation by X. axonopodis pv. citri strain XW19, the strain was subjected to transposon mutagenesis. One mutant with a mutation in a two-component response regulator gene that was deficient in biofilm formation on a polystyrene microplate was selected for further study. The protein was designated as BfdR for biofilm formation defective regulator. BfdR from strain XW19 shares 100% amino acid sequence identity with XAC1284 of X. axonopodis pv. citri strain 306 and 30-100% identity with two-component response regulators in various pathogens and environmental microorganisms. The bfdR mutant strain exhibited significantly decreased biofilm formation on the leaf surfaces of Mexican lime compared with the wild type strain. The bfdR mutant was also compromised in its ability to cause canker lesions. The wild-type phenotype was restored by providing pbfdR in trans in the bfdR mutant. Our data indicated that BfdR did not regulate the production of virulence-related extracellular enzymes including amylase, lipase, protease, and lecithinase or the expression of hrpG, rfbC, and katE; however, BfdR controlled the expression of rpfF in XVM2 medium, which mimics cytoplasmic fluids in planta. In conclusion, biofilm formation on leaf surfaces of citrus is important for canker development in X. axonopodis pv. citri XW19. The process is controlled by the two-component response regulator BfdR via regulation of rpfF, which is required for the biosynthesis of a diffusible signal factor.

  6. A LOV protein modulates the physiological attributes of Xanthomonas axonopodis pv. citri relevant for host plant colonization.

    Directory of Open Access Journals (Sweden)

    Ivana Kraiselburd

    Full Text Available Recent studies have demonstrated that an appropriate light environment is required for the establishment of efficient vegetal resistance responses in several plant-pathogen interactions. The photoreceptors implicated in such responses are mainly those belonging to the phytochrome family. Data obtained from bacterial genome sequences revealed the presence of photosensory proteins of the BLUF (Blue Light sensing Using FAD, LOV (Light, Oxygen, Voltage and phytochrome families with no known functions. Xanthomonas axonopodis pv. citri is a Gram-negative bacterium responsible for citrus canker. The in silico analysis of the X. axonopodis pv. citri genome sequence revealed the presence of a gene encoding a putative LOV photoreceptor, in addition to two genes encoding BLUF proteins. This suggests that blue light sensing could play a role in X. axonopodis pv. citri physiology. We obtained the recombinant Xac-LOV protein by expression in Escherichia coli and performed a spectroscopic analysis of the purified protein, which demonstrated that it has a canonical LOV photochemistry. We also constructed a mutant strain of X. axonopodis pv. citri lacking the LOV protein and found that the loss of this protein altered bacterial motility, exopolysaccharide production and biofilm formation. Moreover, we observed that the adhesion of the mutant strain to abiotic and biotic surfaces was significantly diminished compared to the wild-type. Finally, inoculation of orange (Citrus sinensis leaves with the mutant strain of X. axonopodis pv. citri resulted in marked differences in the development of symptoms in plant tissues relative to the wild-type, suggesting a role for the Xac-LOV protein in the pathogenic process. Altogether, these results suggest the novel involvement of a photosensory system in the regulation of physiological attributes of a phytopathogenic bacterium. A functional blue light receptor in Xanthomonas spp. has been described for the first time, showing

  7. Signalering van citruswolluis (Planococcus citri) in de teelt van diverse potplanten : onderzoek binnen project 41203147 "Verbetering biologische bestrijding van wolluis in diverse potplanten”

    NARCIS (Netherlands)

    Boertjes, B.C.; Bruin, de J.

    2003-01-01

    In 2002 en 2003 is door PPO Glastuinbouw het project “Verbetering biologische bestrijding van wolluis in diverse potplanten” (project 41203147) uitgevoerd. Binnen dit project werd onder meer onderzoek gedaan naar methoden om citruswolluis (Planococcus citri) te signaleren.

  8. A molecular phylogeny of Hemiptera inferred from mitochondrial genome sequences.

    Directory of Open Access Journals (Sweden)

    Nan Song

    Full Text Available Classically, Hemiptera is comprised of two suborders: Homoptera and Heteroptera. Homoptera includes Cicadomorpha, Fulgoromorpha and Sternorrhyncha. However, according to previous molecular phylogenetic studies based on 18S rDNA, Fulgoromorpha has a closer relationship to Heteroptera than to other hemipterans, leaving Homoptera as paraphyletic. Therefore, the position of Fulgoromorpha is important for studying phylogenetic structure of Hemiptera. We inferred the evolutionary affiliations of twenty-five superfamilies of Hemiptera using mitochondrial protein-coding genes and rRNAs. We sequenced three mitogenomes, from Pyrops candelaria, Lycorma delicatula and Ricania marginalis, representing two additional families in Fulgoromorpha. Pyrops and Lycorma are representatives of an additional major family Fulgoridae in Fulgoromorpha, whereas Ricania is a second representative of the highly derived clade Ricaniidae. The organization and size of these mitogenomes are similar to those of the sequenced fulgoroid species. Our consensus phylogeny of Hemiptera largely supported the relationships (((Fulgoromorpha,Sternorrhyncha,Cicadomorpha,Heteroptera, and thus supported the classic phylogeny of Hemiptera. Selection of optimal evolutionary models (exclusion and inclusion of two rRNA genes or of third codon positions of protein-coding genes demonstrated that rapidly evolving and saturated sites should be removed from the analyses.

  9. KatG, the Bifunctional Catalase of Xanthomonas citri subsp. citri, Responds to Hydrogen Peroxide and Contributes to Epiphytic Survival on Citrus Leaves

    Science.gov (United States)

    Tondo, María Laura; Delprato, María Laura; Kraiselburd, Ivana; Fernández Zenoff, María Verónica; Farías, María Eugenia; Orellano, Elena G.

    2016-01-01

    Xanthomonas citri subsp. citri (Xcc) is the bacterium responsible for citrus canker. This bacterium is exposed to reactive oxygen species (ROS) at different points during its life cycle, including those normally produced by aerobic respiration or upon exposition to ultraviolet (UV) radiation. Moreover, ROS are key components of the host immune response. Among enzymatic ROS-detoxifying mechanisms, catalases eliminate H2O2, avoiding the potential damage caused by this specie. Xcc genome includes four catalase genes. In this work, we studied the physiological role of KatG, the only bifunctional catalase of Xcc, through the construction and characterization of a modified strain (XcckatG), carrying an insertional mutation in the katG gene. First, we evaluated the involvement of KatG in the bacterial adaptive response to H2O2. XcckatG cultures exhibited lower catalase activity than those of the wild-type strain, and this activity was not induced upon treatment with sub-lethal doses of H2O2. Moreover, the KatG-deficient mutant exhibited decreased tolerance to H2O2 toxicity compared to wild-type cells and accumulated high intracellular levels of peroxides upon exposure to sub-lethal concentrations of H2O2. To further study the role of KatG in Xcc physiology, we evaluated bacterial survival upon exposure to UV-A or UV-B radiation. In both conditions, XcckatG showed a high mortality in comparison to Xcc wild-type. Finally, we studied the development of bacterial biofilms. While structured biofilms were observed for the Xcc wild-type, the development of these structures was impaired for XcckatG. Based on these results, we demonstrated that KatG is responsible for Xcc adaptive response to H2O2 and a key component of the bacterial response to oxidative stress. Moreover, this enzyme plays an important role during Xcc epiphytic survival, being essential for biofilm formation and UV resistance. PMID:26990197

  10. The gpsX gene encoding a glycosyltransferase is important for polysaccharide production and required for full virulence in Xanthomonas citri subsp. citri

    Directory of Open Access Journals (Sweden)

    Li Jinyun

    2012-03-01

    Full Text Available Abstract Background The Gram-negative bacterium Xanthomonas citri subsp. citri (Xac causes citrus canker, one of the most destructive diseases of citrus worldwide. In our previous work, a transposon mutant of Xac strain 306 with an insertion in the XAC3110 locus was isolated in a screening that aimed at identifying genes related to biofilm formation. The XAC3110 locus was named as bdp24 for biofilm-defective phenotype and the mutant was observed to be affected in extracellular polysaccharide (EPS and lipopolysaccharide (LPS biosynthesis and cell motility. In this study, we further characterized the bdp24 (XAC3110 gene (designated as gpsX using genetic complementation assays and expanded the knowledge about the function of the gpsX gene in Xac pathogenesis by investigating the roles of gpsX in EPS and LPS production, cell motility, biofilm formation on host leaves, stress tolerance, growth in planta, and host virulence of the citrus canker bacterium. Results The gpsX gene encodes a putative glycosyltransferase, which is highly conserved in the sequenced strains of Xanthomonas. Mutation of gpsX resulted in a significant reduction of the amount of EPS and loss of two LPS bands visualized on sodium dodecylsulphate- polyacrylamide gels. Biofilm assays revealed that the gpsX mutation affected biofilm formation by Xac on abiotic and biotic surfaces. The gpsX mutant showed delayed bacterial growth and caused reduced development of disease symptoms in susceptible citrus leaves. The gpsX mutant was more sensitive than the wild-type strain to various stresses, including the H2O2 oxidative stress. The mutant also showed attenuated ability in cell motility but not in flagellar formation. Quantitative reverse transcription-PCR assays indicated that mutation of gpsX did not affect the expression of virulence genes such as pthA in Xac strain 306. The affected phenotypes of the gpsX mutant could be complemented to wild-type levels by the intact gpsX gene

  11. KatG, the Bifunctional Catalase of Xanthomonas citri subsp. citri, Responds to Hydrogen Peroxide and Contributes to Epiphytic Survival on Citrus Leaves.

    Directory of Open Access Journals (Sweden)

    María Laura Tondo

    Full Text Available Xanthomonas citri subsp. citri (Xcc is the bacterium responsible for citrus canker. This bacterium is exposed to reactive oxygen species (ROS at different points during its life cycle, including those normally produced by aerobic respiration or upon exposition to ultraviolet (UV radiation. Moreover, ROS are key components of the host immune response. Among enzymatic ROS-detoxifying mechanisms, catalases eliminate H2O2, avoiding the potential damage caused by this specie. Xcc genome includes four catalase genes. In this work, we studied the physiological role of KatG, the only bifunctional catalase of Xcc, through the construction and characterization of a modified strain (XcckatG, carrying an insertional mutation in the katG gene. First, we evaluated the involvement of KatG in the bacterial adaptive response to H2O2. XcckatG cultures exhibited lower catalase activity than those of the wild-type strain, and this activity was not induced upon treatment with sub-lethal doses of H2O2. Moreover, the KatG-deficient mutant exhibited decreased tolerance to H2O2 toxicity compared to wild-type cells and accumulated high intracellular levels of peroxides upon exposure to sub-lethal concentrations of H2O2. To further study the role of KatG in Xcc physiology, we evaluated bacterial survival upon exposure to UV-A or UV-B radiation. In both conditions, XcckatG showed a high mortality in comparison to Xcc wild-type. Finally, we studied the development of bacterial biofilms. While structured biofilms were observed for the Xcc wild-type, the development of these structures was impaired for XcckatG. Based on these results, we demonstrated that KatG is responsible for Xcc adaptive response to H2O2 and a key component of the bacterial response to oxidative stress. Moreover, this enzyme plays an important role during Xcc epiphytic survival, being essential for biofilm formation and UV resistance.

  12. KatG, the Bifunctional Catalase of Xanthomonas citri subsp. citri, Responds to Hydrogen Peroxide and Contributes to Epiphytic Survival on Citrus Leaves.

    Science.gov (United States)

    Tondo, María Laura; Delprato, María Laura; Kraiselburd, Ivana; Fernández Zenoff, María Verónica; Farías, María Eugenia; Orellano, Elena G

    2016-01-01

    Xanthomonas citri subsp. citri (Xcc) is the bacterium responsible for citrus canker. This bacterium is exposed to reactive oxygen species (ROS) at different points during its life cycle, including those normally produced by aerobic respiration or upon exposition to ultraviolet (UV) radiation. Moreover, ROS are key components of the host immune response. Among enzymatic ROS-detoxifying mechanisms, catalases eliminate H2O2, avoiding the potential damage caused by this specie. Xcc genome includes four catalase genes. In this work, we studied the physiological role of KatG, the only bifunctional catalase of Xcc, through the construction and characterization of a modified strain (XcckatG), carrying an insertional mutation in the katG gene. First, we evaluated the involvement of KatG in the bacterial adaptive response to H2O2. XcckatG cultures exhibited lower catalase activity than those of the wild-type strain, and this activity was not induced upon treatment with sub-lethal doses of H2O2. Moreover, the KatG-deficient mutant exhibited decreased tolerance to H2O2 toxicity compared to wild-type cells and accumulated high intracellular levels of peroxides upon exposure to sub-lethal concentrations of H2O2. To further study the role of KatG in Xcc physiology, we evaluated bacterial survival upon exposure to UV-A or UV-B radiation. In both conditions, XcckatG showed a high mortality in comparison to Xcc wild-type. Finally, we studied the development of bacterial biofilms. While structured biofilms were observed for the Xcc wild-type, the development of these structures was impaired for XcckatG. Based on these results, we demonstrated that KatG is responsible for Xcc adaptive response to H2O2 and a key component of the bacterial response to oxidative stress. Moreover, this enzyme plays an important role during Xcc epiphytic survival, being essential for biofilm formation and UV resistance.

  13. 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.

  14. Overexpression of citrus polygalacturonase-inhibiting protein in citrus black rot pathogen Alternaria citri.

    Science.gov (United States)

    Katoh, Hiroshi; Nalumpang, Sarunya; Yamamoto, Hiroyuki; Akimitsu, Kazuya

    2007-05-01

    The rough lemon (Citrus jambhiri) gene encoding polygalacturonase-inhibiting protein (RlemPGIPA) was overexpressed in the pathogenic fungus Alternaria citri. The overexpression mutant AcOPI6 retained the ability to utilize pectin as a sole carbon source, and the overexpression of polygalacturonase-inhibiting protein did not have any effect on the growth of AcOPI6 in potato dextrose and pectin medium. The pathogenicity of AcOPI6 to cause a black rot symptom in citrus fruits was also unchanged. Polygalacturonase-inhibiting protein was secreted together with endopolygalacturonase into culture filtrates of AcOPI6, and oligogalacturonides were digested from polygalacturonic acid by both proteins in the culture filtrates. The reaction mixture containing oligogalacturonides possessed activity for induction of defense-related gene, RlemLOX, in rough lemon leaves.

  15. Compatibility of Isaria fumosorosea (Hypocreales: Cordycipitaceae Blastospores with Agricultural Chemicals Used for Management of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae

    Directory of Open Access Journals (Sweden)

    Pasco B. Avery

    2013-11-01

    Full Text Available Biorational insecticides are being increasingly emphasized for inclusion in integrated pest management programs for invasive insects. The entomopathogenic fungus, Isaria fumosorosea, can be used to help manage the Asian citrus psyllid with minimal impact on beneficial arthropods, but its effectiveness may be compromised by agrochemicals used to control concurrent arthropod pests and diseases. We evaluated the compatibility of I. fumosorosea blastospores with a range of spray oils and copper-based fungicides registered for use in citrus groves. Results of laboratory and greenhouse tests showed a range of responses of the fungus to the different materials, including compatibility and incompatibility. Overall, I. fumosorosea growth in vitro was reduced least by petroleum-based materials and most by botanical oils and borax, and some of the copper-based fungicides, suggesting that tank mixing of I. fumosorosea with these latter products should be avoided. However, equivalent negative effects of test materials on fungal pathogenicity were not always observed in tests with adult psyllids. We hypothesize that some oils enhanced adherence of blastospores to the insect cuticle, overcoming negative impacts on germination. Our data show that care should be taken in selecting appropriate agrochemicals for tank-mixing with commercial formulations of entomopathogenic fungi for management of citrus pests. The prospects of using I. fumosorosea for managing the invasive Asian citrus psyllid and other citrus pests are discussed.

  16. Chemotactic signal transduction and phosphate metabolism as adaptive strategies during citrus canker induction by Xanthomonas citri.

    Science.gov (United States)

    Moreira, Leandro Marcio; Facincani, Agda Paula; Ferreira, Cristiano Barbalho; Ferreira, Rafael Marine; Ferro, Maria Inês Tiraboshi; Gozzo, Fabio Cesar; de Oliveira, Julio Cezar Franco; Ferro, Jesus Aparecido; Soares, Márcia Regina

    2015-03-01

    The genome of Xanthomonas citri subsp. Citri strain 306 pathotype A (Xac) was completely sequenced more than 10 years; to date, few studies involving functional genomics Xac and its host compatible have been developed, specially related to adaptive events that allow the survival of Xac within the plant. Proteomic analysis of Xac showed that the processes of chemotactic signal transduction and phosphate metabolism are key adaptive strategies during the interaction of a pathogenic bacterium with its plant host. The results also indicate the importance of a group of proteins that may not be directly related to the classical virulence factors, but that are likely fundamental to the success of the initial stages of the infection, such as methyl-accepting chemotaxis protein (Mcp) and phosphate specific transport (Pst). Furthermore, the analysis of the mutant of the gene pstB which codifies to an ABC phosphate transporter subunit revealed a complete absence of citrus canker symptoms when inoculated in compatible hosts. We also conducted an in silico analysis which established the possible network of genes regulated by two-component systems PhoPQ and PhoBR (related to phosphate metabolism), and possible transcriptional factor binding site (TFBS) motifs of regulatory proteins PhoB and PhoP, detaching high degree of conservation of PhoB TFBS in 84 genes of Xac genome. This is the first time that chemotaxis signal transduction and phosphate metabolism were therefore indicated to be fundamental to the process of colonization of plant tissue during the induction of disease associated with Xanthomonas genus bacteria.

  17. Crystal Structure of the FAD-Containing Ferredoxin-NADP+ Reductase from the Plant Pathogen Xanthomonas axonopodis pv. citri

    Directory of Open Access Journals (Sweden)

    María Laura Tondo

    2013-01-01

    Full Text Available We have solved the structure of ferredoxin-NADP(H reductase, FPR, from the plant pathogen Xanthomonas axonopodis pv. citri, responsible for citrus canker, at a resolution of 1.5 Å. This structure reveals differences in the mobility of specific loops when compared to other FPRs, probably unrelated to the hydride transfer process, which contributes to explaining the structural and functional divergence between the subclass I FPRs. Interactions of the C-terminus of the enzyme with the phosphoadenosine of the cofactor FAD limit its mobility, thus affecting the entrance of nicotinamide into the active site. This structure opens the possibility of rationally designing drugs against the X. axonopodis pv. citri phytopathogen.

  18. De novo characterization of the Dialeurodes citri transcriptome: mining genes involved in stress resistance and simple sequence repeats (SSRs) discovery.

    Science.gov (United States)

    Chen, E-H; Wei, D-D; Shen, G-M; Yuan, G-R; Bai, P-P; Wang, J-J

    2014-02-01

    The citrus whitefly, Dialeurodes citri (Ashmead), is one of the three economically important whitefly species that infest citrus plants around the world; however, limited genetic research has been focused on D. citri, partly because of lack of genomic resources. In this study, we performed de novo assembly of a transcriptome using Illumina paired-end sequencing technology (Illumina Inc., San Diego, CA, USA). In total, 36,766 unigenes with a mean length of 497 bp were identified. Of these unigenes, we identified 17,788 matched known proteins in the National Center for Biotechnology Information database, as determined by Blast search, with 5731, 4850 and 14,441 unigenes assigned to clusters of orthologous groups (COG), gene ontology (GO), and SwissProt, respectively. In total, 7507 unigenes were assigned to 308 known pathways. In-depth analysis of the data showed that 117 unigenes were identified as potentially involved in the detoxification of xenobiotics and 67 heat shock protein (Hsp) genes were associated with environmental stress. In addition, these enzymes were searched against the GO and COG database, and the results showed that the three major detoxification enzymes and Hsps were classified into 18 and 3, 6, and 8 annotations, respectively. In addition, 149 simple sequence repeats were detected. The results facilitate the investigation of molecular resistance mechanisms to insecticides and environmental stress, and contribute to molecular marker development. The findings greatly improve our genetic understanding of D. citri, and lay the foundation for future functional genomics studies on this species.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Essential oils as fumigants for bed bugs (Hemiptera: Cimicidae)

    Science.gov (United States)

    In Petri dish assays, fumigation of a pyrethroid-susceptible strain of bed bugs Cimex lectularius L. (Hemiptera: Cimicidae) with various essential oils resulted in mortality that approached or equaled 100%, after 5 days. However, when bed bugs were exposed to the same essential oils in sealed, comme...

  1. Release and establishment of Megamelus scutellaris (Hemiptera: Delphacidae) in Florida

    Science.gov (United States)

    Megamelus scutellaris (Berg) (Hemiptera: Delphacidae) was recently developed as a classical biological control agent for waterhyacinth, Eichhornia crassipes Mart. Solms, and released in Florida. Releases were conducted at 10 sites around the state every 4-6 weeks until late fall then halted until t...

  2. Catalog of the adelgids of the world (Hemiptera: Adelgidae)

    Science.gov (United States)

    A taxonomic and nomenclatural catalog of the adelgids (Hemiptera: Adelgidae) is presented. Six family-group names are listed, five being synonyms of Adelgidae. Twenty-two genus-group names, of which nine are valid and in use, are presented with their type species, etymology, and grammatical gender. ...

  3. Developing resistance for watermelon against whiteflies (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    Host plant resistance is a fundamental component of crop sustainability. The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is a key pest of many crops around the world. It is adaptive to its environment and feeds on an impressive (over 1,000) number of plant species. Watermelon (Cit...

  4. New excised-leaf assay method to test inoculativity of Asian citrus psyllid (Hemiptera: Psyllidae) with Candidatus Liberibacter asiaticus associated with citrus huanglongbing disease.

    Science.gov (United States)

    Ammar, El-Desouky; Walter, Abigail J; Hall, David G

    2013-02-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the primary vector of Candidatus Liberibacter asiaticus (Las) associated with huanglongbing, or citrus greening, the most devastating citrus (Citrus spp.) disease worldwide. Here, we developed a new "excised-leaf assay" that can speed up Las-inoculativity tests on Asian citrus psyllid from the current 3-12 mo (when using whole citrus seedlings for inoculation) to only 2-3 wk. Young adults of Asian citrus psyllid that had been reared on Las-infected plants were caged on excised healthy sweet orange [Citrus sinensis (L.) Osbeck] leaves for a 1-2-wk inoculation access periods (IAP), and then both psyllids and leaves were tested later by quantitative polymerase chain reaction (PCR). When single adults were tested per leaf, percentages of Las-positive leaves averaged 2-6% by using HLBaspr primers and 10-20% by using the more sensitive LJ900 primers. Higher proportions of Las-positive leaves were obtained with 1) higher densities of inoculating psyllids (5-10 adults per leaf), 2) longer IAPs, and 3) incubation of leaves for 1 wk postinoculation before PCR. Logistic regression analysis indicated a positive correlation between Las titer in Asian citrus psyllid adults tested singly and the probability of detecting Las in the inoculated leaves, correlations that can be very useful in epidemiological studies. Comparison between excised leaves and whole seedlings, inoculated consecutively for 1 wk each by one or a group of psyllids, indicated no significant difference between Las detection in excised leaves or whole plants. This new excised-leaf assay method saves considerable time, materials, and greenhouse space, and it may enhance vector relation and epidemiological studies on Las and potentially other Liberibacter spp. associated with huanglongbing disease.

  5. DNA barcodes for Nearctic Auchenorrhyncha (Insecta: Hemiptera.

    Directory of Open Access Journals (Sweden)

    Robert G Foottit

    Full Text Available BACKGROUND: Many studies have shown the suitability of sequence variation in the 5' region of the mitochondrial cytochrome c oxidase I (COI gene as a DNA barcode for the identification of species in a wide range of animal groups. We examined 471 species in 147 genera of Hemiptera: Auchenorrhyncha drawn from specimens in the Canadian National Collection of Insects to assess the effectiveness of DNA barcoding in this group. METHODOLOGY/PRINCIPAL FINDINGS: Analysis of the COI gene revealed less than 2% intra-specific divergence in 93% of the taxa examined, while minimum interspecific distances exceeded 2% in 70% of congeneric species pairs. Although most species are characterized by a distinct sequence cluster, sequences for members of many groups of closely related species either shared sequences or showed close similarity, with 25% of species separated from their nearest neighbor by less than 1%. CONCLUSIONS/SIGNIFICANCE: This study, although preliminary, provides DNA barcodes for about 8% of the species of this hemipteran suborder found in North America north of Mexico. Barcodes can enable the identification of many species of Auchenorrhyncha, but members of some species groups cannot be discriminated. Future use of DNA barcodes in regulatory, pest management, and environmental applications will be possible as the barcode library for Auchenorrhyncha expands to include more species and broader geographic coverage.

  6. The effect of Leptomastix dactylopii parasitism and venom injection on host Planococcus citri

    Directory of Open Access Journals (Sweden)

    D Battaglia

    2014-10-01

    Full Text Available One of the major alterations observed in mealybug Planococcus citri parasitized by Leptomastix dactylopii is a strong reduction of laid eggs, which is evident soon after parasitization. Venom injection in unparasitized hosts determines a drastic reduction of fecundity indicating that this female secretion injected at the oviposition plays a key-role in host regulation. In order to assess the impact of parasitism and venom injection on host reproductive tissues, ovaries were dissected at different time intervals after these treatments and observed by light and transmission electron microscopy. The developing eggs showed clear symptoms of degeneration, already half an hour after parasitization or venom injection. Heat and protease treatments of venom nearly suppressed its effects on host reproduction, indicating that proteins are likely responsible for the observed alterations. The electrophoretic profile of venom proteins covers a wide range of molecular masses between 15 to 200 kDa but five major bands having a molecular mass of about 27, 30, 40, 90 and 120 kDa respectively were more evident. Moreover, to establish any parasitoid preference in host selection, among the adult female mealybugs at different stages of maturation and a possible relation with fecundity reduction in the host, the parasitoid behavior was observed.

  7. Genomic insights into the evolutionary origin of Xanthomonas axonopodis pv. citri and its ecological relatives.

    Science.gov (United States)

    Midha, Samriti; Patil, Prabhu B

    2014-10-01

    Xanthomonas axonopodis pv. citri (Xac) is the causal agent of citrus bacterial canker (CBC) and is a serious problem worldwide. Like CBC, several important diseases in other fruits, such as mango, pomegranate, and grape, are also caused by Xanthomonas pathovars that display remarkable specificity toward their hosts. While citrus and mango diseases were documented more than 100 years ago, the pomegranate and grape diseases have been known only since the 1950s and 1970s, respectively. Interestingly, diseases caused by all these pathovars were noted first in India. Our genome-based phylogenetic studies suggest that these diverse pathogens belong to a single species and these pathovars may be just a group of rapidly evolving strains. Furthermore, the recently reported pathovars, such as those infecting grape and pomegranate, form independent clonal lineages, while the citrus and mango pathovars that have been known for a long time form one clonal lineage. Such an understanding of their phylogenomic relationship has further allowed us to understand major and unique variations in the lineages that give rise to these pathovars. Whole-genome sequencing studies including ecological relatives from their putative country of origin has allowed us to understand the evolutionary history of Xac and other pathovars that infect fruits.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Identification of anti-asthmatic compounds in Pericarpium citri reticulatae and evaluation of their synergistic effects

    Institute of Scientific and Technical Information of China (English)

    Qian SHI; Ze LIU; Yang YANG; Peng GENG; Yuan-yuan ZHU; Qi ZHANG; Fang BAI; Gang BAI

    2009-01-01

    Aim: To investigate the anti-asthmatic mechanisms of the traditional Chinese medicine Pericarpium citri reticulatae (PCR).Methods: The alkaloid section (AS) of PCR was extracted using an ion exchange resin, separated, and purified into different fractions by semi-preparative HPLC. These fractions were screened for beta2-adrenergic receptor (β2AR) agonistic activity using rat β2AR-transfected CHO-CRE-EGFP cells. AS and its isolated components were characterized by ultra-performance liquid chromatography/quadrupole time-of-flight MS (UPLC/Q-Tof MS) and were evaluated for their spasmolytic and antitussive activities both in vitro and in vivo in a guinea pig model.Results: We demonstrated that the AS component responsible for activating β2AR signaling was synephrine. Both AS and synephrine showed significant spasmolytic effects on acetylcholine chloride (ACh)-induced contractions in isolated guinea pig trachea, and they protected against histamine-induced experimental asthma by prolonging the latent period. We further identified stachydrine as the antitussive component that could significantly reduce citric acid-induced coughing. The combination of these two bioactive compounds had a more potent spasmolytic activity in comparison with the single use of synephrine or stachydrine.Conclusion: We conclude that synephrine and stachydrine are the key components of AS that mediate asthma relief due to their synergism when used in combination.

  10. Pathogenic Interactions Between Xanthomonas axonopodis pv. citri and Cultivars of Pummelo (Citrus grandis).

    Science.gov (United States)

    Shiotani, H; Ozaki, K; Tsuyumu, S

    2000-12-01

    ABSTRACT The aggressiveness of strains of Xanthomonas axonopodis pv. citri on seven Citrus species, including Citrus sinensis (navel orange), C. paradisi (grapefruit), C. unshiu (Satsuma mandarin), C. junos (Yuzu), C. aurantifolia ('Mexican' lime), C. tachibana (Tachibana), and C. grandis (pummelo: 'Otachibana', 'Banpeiyu', and 'Anseikan'), were assessed by comparing lesion expansion and growth in planta, using a prick inoculation method. The existence of two groups distinct in aggressiveness was demonstrated on the pummelo cultivars, whereas the remaining species tested were uniformly susceptible. The two groups of strains were distinct in lesion expansion and growth in planta; however, both caused canker lesions on the 'Otachibana' pummelo. The sensitivity of the bacterial strains to phages Cp1 and Cp2 was associated with differences in aggressiveness. Namely, all the strains sensitive to Cp2 but resistant to Cp1 were aggressive to 'Otachibana', whereas all the strains sensitive to Cp1 but resistant to Cp2 were weakly aggressive. When a repetitive sequence-based polymerase chain reaction amplification was carried out by enterobacterial repetitive intergeneric consensus (ERIC) sequences (ERIC1R and ERIC2) as the primers, these two groups were also distinguishable by the presence or absence of a 1.8-kb DNA fragment among otherwise identical fragments. The 1.8-kb fragment was amplified only from the strains aggressive to C. grandis.

  11. Remote Sensing of Low and Mid-Latitude Ionospheric Disturbances During Solar Minimum Using CITRIS and CERTO Measurements of TEC and Radio Scintillation

    Science.gov (United States)

    Siefring, C. L.; Bernhardt, P. A.

    2010-12-01

    Unique data on ionospheric plasma disturbances from the Naval Research Laboratory 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) three-frequency beacons transmitting at 150/400/1067 MHz and 2) the French global network of ground-based DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) beacons transmitting at 401.25 and 2036.25 MHz. CITRIS was operated in a complementary fashion with the C/NOFS satellite during most of its first year of operations; C/NOFS carries CERTO beacon along with in-situ diagnostics. CITRIS and ground receivers can simultaneously measure TEC and scintillations on different paths using CERTO on C/NOFS. When C/NOFS is not in view, CITRIS makes measurements from DORIS beacons and other LEO satellites. Because of the orbits CITRIS will always make measurements at the same longitude within 48 min of C/NOFS. The ability to look at multiple paths is unique and useful for studying the spatial extent and time duration of disturbances. The combination of TEC and scintillation measurements provides information on a range of scale-sizes from >1 km to about 100 m. The joint data set on plasma structures at low-latitudes is a focus of our presentation, with the addition of comparisons to CITRIS data taken at mid-latitude. Several types of irregularities have been studied including Spread-F and the newly discovered dawn-side depletions. The data covers large portions of the Earth (including the Pacific, African and South American sectors) during an unusually quite portion of the most

  12. Endemism analysis of Neotropical Pentatomidae (Hemiptera, Heteroptera

    Directory of Open Access Journals (Sweden)

    Augusto Ferrari

    2010-12-01

    Full Text Available The definition of areas of endemism is central to studies of historical biogeography, and their interrelationships are fundamental questions. Consistent hypotheses for the evolution of Pentatomidae in the Neotropical region depend on the accuracy of the units employed in the analyses, which in the case of studies of historical biogeography, may be areas of endemism. In this study, the distribution patterns of 222 species, belonging to 14 Pentatomidae (Hemiptera genera, predominantly neotropical, were studied with the Analysis of Endemicity (NDM to identify possible areas of endemism and to correlate them to previously delimited areas. The search by areas of endemism was carried out using grid-cell units of 2.5° and 5° latitude-longitude. The analysis based on groupings of grid-cells of 2.5° of latitude-longitude allowed the identification of 51 areas of endemism, the consensus of these areas resulted in four clusters of grid-cells. The second analysis, with grid-cells units of 5° latitude-longitude, resulted in 109 areas of endemism. The flexible consensus employed resulted in 17 areas of endemism. The analyses were sensitive to the identification of areas of endemism in different scales in the Atlantic Forest. The Amazonian region was identified as a single area in the area of consensus, and its southeastern portion shares elements with the Chacoan and Paraná subregions. The distribution data of the taxa studied, with different units of analysis, did not allow the identification of individual areas of endemism for the Cerrado and Caatinga. The areas of endemism identified here should be seen as primary biogeographic hypotheses.

  13. Characterization of bacteriophages Cp1 and Cp2, the strain-typing agents for Xanthomonas axonopodis pv. citri.

    Science.gov (United States)

    Ahmad, Abdelmonim Ali; Ogawa, Megumi; Kawasaki, Takeru; Fujie, Makoto; Yamada, Takashi

    2014-01-01

    The strains of Xanthomonas axonopodis pv. citri, the causative agent of citrus canker, are historically classified based on bacteriophage (phage) sensitivity. Nearly all X. axonopodis pv. citri strains isolated from different regions in Japan are lysed by either phage Cp1 or Cp2; Cp1-sensitive (Cp1(s)) strains have been observed to be resistant to Cp2 (Cp2(r)) and vice versa. In this study, genomic and molecular characterization was performed for the typing agents Cp1 and Cp2. Morphologically, Cp1 belongs to the Siphoviridae. Genomic analysis revealed that its genome comprises 43,870-bp double-stranded DNA (dsDNA), with 10-bp 3'-extruding cohesive ends, and contains 48 open reading frames. The genomic organization was similar to that of Xanthomonas phage phiL7, but it lacked a group I intron in the DNA polymerase gene. Cp2 resembles morphologically Escherichia coli T7-like phages of Podoviridae. The 42,963-bp linear dsDNA genome of Cp2 contained terminal repeats. The Cp2 genomic sequence has 40 open reading frames, many of which did not show detectable homologs in the current databases. By proteomic analysis, a gene cluster encoding structural proteins corresponding to the class III module of T7-like phages was identified on the Cp2 genome. Therefore, Cp1 and Cp2 were found to belong to completely different virus groups. In addition, we found that Cp1 and Cp2 use different molecules on the host cell surface as phage receptors and that host selection of X. axonopodis pv. citri strains by Cp1 and Cp2 is not determined at the initial stage by binding to receptors.

  14. 60Co-γ Irradiation Affects the Enzymatic Antioxidant System of the Citrus Red Mite Panonychus citri (Acari: Tetranychidae

    Directory of Open Access Journals (Sweden)

    Ke Zhang

    2014-05-01

    Full Text Available Radio-(60Co, which emits γ rays, has been used worldwide in pest control. The aim of the present study was to analyze the effect of effective-low-power 60Co-γ irradiation on the enzymatic antioxidant system of the citrus red mite Panonychus citri. One day old female adults were exposed to 0.4 kGy 60Co-γ irradiation and on the, 6th h, 1st day, 2nd day, and 5th day post treatment, the mites were euthanized for biochemical analysis. The activity of superoxide dismutase (SOD, catalase (CAT, peroxidase (POD, phenoloxidase (PO and acetylocholinesterase (AchE were investigated. POD and CAT activities, as well as SOD were higher in the irradiated mites. We found that exposure to 60Co-γ radiation resulted in increased activities of SOD, CAT, POD and decreased AchE activity. When the recovery time lasted till the 5th day, the activities of POD and PO were significantly lower than the control, whereas the SOD, CAT and AchE activities returned to control levels. Cells possess protein repair pathways to rescue oxidized proteins and restore their functions, but if these repair processes fail, oxidized proteins may become cytotoxic. Our results confirm the hypothesis that low dosages of 60Co-γ irradiation increase the level of oxidative stress in P. citri adults in a short time, causing meanwhile damage and sterility. The results of this study also indicate that stress caused by exposure to irradiation could inhibit the cholinergic system in P. citri.

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

    Energy Technology Data Exchange (ETDEWEB)

    Cary; R. Bruce (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.

  16. Determination of Alternaria Brown Spot (Alternaria alternata f.sp. citri) Disease on Minneola Tangelo in Çukurova Region

    OpenAIRE

    ERKILIÇ, Ali; CANIHOŞ, Yeter; BİÇİCİ, Mehmet

    1998-01-01

    In this study, the incidence and severity of Alternaria brown spot disease (Alternaria alternata f.sp. citri) in the Çukurova region were determined. Thirty-five Minneola tangelo orchards, with a total area of 2497 da, in 24 different locations were surveyed for this purpose. Leaf infections in all orchards were observed in the spring flushing period. Disease severity was found to be 0-10 % in 10 orchards, 11-20 % in 10 orchards, 21-30 % in 7 orchards, 31-40 % in 5 orchards, 42.5 % in 1 orch...

  17. An overview on the ecology of Triatominae (Hemiptera:Reduviidae).

    Science.gov (United States)

    Galvão, Cleber; Justi, Silvia A

    2015-11-01

    Chagas disease, the American trypanosomiasis, is an important neglected tropical illness caused by the flagellate protozoan Trypanosoma cruzi (Kinetoplastida, Trypanosomatidae) and transmitted by insects of the subfamily Triatominae (Hemiptera: Reduviidae). Here we provide an overview on the current knowledge about Triatominae ecology, its association with human, T. cruzi infection and the immediate consequences of habitat fragmentation. We also discuss the geographic distribution of the species and the importance of predicting their distributions to control programs.

  18. Catalog of the adelgids of the world (Hemiptera, Adelgidae).

    Science.gov (United States)

    Favret, Colin; Havill, Nathan P; Miller, Gary L; Sano, Masakazu; Victor, Benjamin

    2015-01-01

    A taxonomic and nomenclatural Catalogue of the adelgids (Hemiptera: Adelgidae) is presented. Six family-group names are listed, five being synonyms of Adelgidae. Twenty-two genus-group names, of which nine are subjectively valid and in use, are presented with their type species, etymology, and grammatical gender. One hundred and six species-group names are listed, of which 70 are considered subjectively valid.

  19. Characterization of three linalool synthase genes from Citrus unshiu Marc. and analysis of linalool-mediated resistance against Xanthomonas citri subsp. citri and Penicilium italicum in citrus leaves and fruits.

    Science.gov (United States)

    Shimada, Takehiko; Endo, Tomoko; Fujii, Hiroshi; Rodríguez, Ana; Peña, Leandro; Omura, Mitsuo

    2014-12-01

    Three cDNA clones from Satsuma mandarin (Citrus unshiu Marc.) were isolated and expressed in Escherichia coli. CuSTS3-1 and CuSTS3-2 encode linalool synthases and CuSTS4 encodes a nerolidol/linalool synthase. Transcripts of CuSTS3-1, CuSTS3-2 and CuSTS4 were abundant in young fruit at 60 days after flowering (DAF), flowers and leaves, respectively. Treatments with Xanthomonas citri subsp. citri (XCC), the causal agent of citrus canker and Penicillium italicum (PI), the cause of post-harvest fruit decay, and wounding up-regulated CuSTS3-1 in fruit and mainly CuSTS4 in leaves. Linalool, citral, geraniol and citronellol showed strong antibacterial and antifungal activities against XCC and PI in vitro, while most other mono-and sesquiterpenes, including limonene and gamma-terpinene, did not. Linalool, used at levels similar to those present in resistant Ponkan mandarin (Citrus reticulata Blanco) leaves, was able to inhibit growth of XCC in vitro. Compared to other five citrus types, linalool accumulated at extraordinarily high levels in Ponkan mandarin leaves and was released at high amounts from their leaves, while it was hardly detectable in the most susceptible species, indicating that linalool biosynthesis and accumulation might be involved in plant defense against bacterial and fungal pathogens and be associated with field resistance to citrus canker.

  20. Overexpression of a Gene Encoding a Catabolite Repression Element in Alternaria citri Causes Severe Symptoms of Black Rot in Citrus Fruit.

    Science.gov (United States)

    Katoh, H; Ohtani, K; Yamamoto, H; Akimitsu, K

    2007-05-01

    ABSTRACT A gene (AcCreA) encoding a catabolite repression element (CreA) with (two zinc fingers of the Cys(2)His(2) type was isolated from the postharvest fungal pathogen Alternaria citri. The AcCreA overexpression mutant AcOEC2 of A. citri showed normal growth on pectin medium and on segments of peel or the juice sac area from citrus fruit. Production of endopolygalacturonase, an essential virulence factor of this pathogen, was similar in AcOEC2 and the wild type in pectin-containing media. However, addition of glucose to the medium showed that carbon catabolite repression of endopolygalacturonase gene (Acpg1) expression, as well as endopolygalacturonase production, was lost in AcOEC2. The wild-type strain of A. citri causes rot mainly in the central axis of citrus fruit without development of rotting in the juice sac area; however, AcOEC2 caused severe black rot symptoms in both the central axis and juice sac areas. These results indicate that AcCreA-mediated catabolite repression controls the virulence or infection of this pathogen, and that the wild-type A. citri does not cause symptoms in the juice sac area due to carbon catabolite repression by sugars in the juice of the juice sac area.

  1. 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...

  2. Titers of 'Ca. Liberibacter asiaticus' in Murraya paniculata and Murraya-reared Diaphorina citri are much lower than in citrus and citrus-reared psyllids

    Science.gov (United States)

    Huanglongbing, one of the most devastating diseases of citrus, is associated with the bacterium Candidatus Liberibacter asiaticus vectored by the Asian citrus psyllid, Diaphorina citri, in North America. Murraya paniculata is a common ornamental plant that is an alternate host of Ca. L. asiaticus an...

  3. The complete mitochondrial genome of a spiraling whitefly, Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Ming-Xing, Lu; Zhi-Teng, Chen; Wei-Wei, Yu; Yu-Zhou, Du

    2017-03-01

    We report the complete mitochondrial genome (mitogenome) of a spiraling whitefly, Aleurodicus dispersus (Hemiptera: Aleyrodidae). The 16 170 bp long genome consists of 13 protein-coding genes, 20 transfer RNAs, 2 ribosomal RNAs, and a control region. The A. dispersus mitogenome also includes a cytb-like non-coding region and shows several variations relative to the typical insect mitogenome. A phylogenetic tree has been constructed using the 13 protein-coding genes of 12 related species from Hemiptera. Our results would contribute to further study of phylogeny in Aleyrodidae and Hemiptera.

  4. (HEMIPTERA: ALEYRODIDAE SOBRE FRÍJOL

    Directory of Open Access Journals (Sweden)

    Luisa Fernanda SUAREZ GONZALEZ

    2015-01-01

    Full Text Available La biología y ecología de la mosca blanca de los invernaderos, Trialeurodes vaporariorum (Westwood (Hemiptera: Aleyroridae, se encuentra ampliamente documentada. Sin embargo, hasta el momento no hay reportes acerca de la tasa de consumo de alimento por este fitófago, un parámetro necesario para modelos de simulación. Por tal motivo, el objetivo de esta investigación fue la medición indirecta del consumo de alimento por el adulto e instares inmaduros de T. vaporariorum basado en metodologías encontradas en la literatura científica. La estimación de la tasa de consumo de alimento por adultos se realizó bajo condiciones de laboratorio, utilizando como unidad experimental una planta de fríjol de dos semanas de edad. El experimento consistió de dos tratamientos: (T1 plantas libres de cualquier fitófago y (T2 plantas sometidas a infestaciones con T. vaporariorum , cada tratamiento con 20 repeticiones y una réplica en el tiempo de todo el experimento. Se registró el peso fresco diariamente en ambos tratamientos. Para el caso de los inmaduros, la unidad experimental consistió en una hoja cotiledónea de fríjol, infestada con una población determinada de inmaduros de cada instar de mosca blanca teniendo así cinco tratamientos (Instar I, II, III, IV y Control cada uno con 17 repeticiones. Se registró diariamente el peso fresco de las hojas. Se obtuvo un consumo promedio de alimento por el adulto de 0,277 ± 0,0042 mg.dia -1 . Para los dos primeros instares ninfales se estimó una tasa de consumo de 0,052 mg.dia -1 , en el tercer instar de 0,14 mg.dia -1 , y para el cuarto instar de 0,19 mg.dia -1 . Un adulto de mosca blanca puede consumir en un día seis veces su peso y un inmaduro ocho veces, gracias a su rápido metabolismo y la constante excreción de mielecilla.

  5. Differential expression of pathogenicity- and virulence-related genes of Xanthomonas axonopodis pv. citri under copper stress

    Directory of Open Access Journals (Sweden)

    Ana Carolina Basílio Palmieri

    2010-01-01

    Full Text Available In this study, we used real-time quantitative PCR (RT-qPCR to evaluate the expression of 32 genes of Xanthomonas axonopodis pv. citri related to pathogenicity and virulence that are also involved in copper detoxification. Nearly all of the genes were up-regulated, including copA and copB. Two genes homologous to members of the type II secretion system (xcsH and xcsC and two involved in the degradation of plant cell wall components (pglA and pel were the most expressed in response to an elevated copper concentration. The type II secretion system (xcs operon and a few homologues of proteins putatively secreted by this system showed enhanced expression when the bacteria were exposed to a high concentration of copper sulfate. The enhanced expression of the genes of secretion II system during copper stress suggests that this pathway may have an important role in the adaptative response of X. axonopodis pv. citri to toxic compounds. These findings highlight the potential role of these genes in attenuating the toxicity of certain metals and could represent an important means of bacterial resistance against chemicals used to control diseases.

  6. 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.

  7. 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.

  8. Functional analysis of a chitinase gene during the larval-nymph transition in Panonychus citri by RNA interference.

    Science.gov (United States)

    Xia, Wen-Kai; Shen, Xiao-Min; Ding, Tian-Bo; Niu, Jin-Zhi; Zhong, Rui; Liao, Chong-Yu; Feng, Ying-Cai; Dou, Wei; Wang, Jin-Jun

    2016-09-01

    Chitinases are hydrolytic enzymes that are required for chitin degradation and reconstruction in arthropods. In this study, we report a cDNA sequence encoding a putative chitinase (PcCht1) from the citrus red mite, Panonychus citri. The PcCht1 (564 aa) possessed a signal peptide, a conserver domain, and a chitin-binding domain. Structural and phylogenetic analyses found that PcCht1 had high sequence similarity to chitinases in Tetranychus urticae. Real-time quantitative PCR analyses showed that the transcript levels of PcCht1 peaked periodically in larval and nymph stages. Moreover, significant increase of PcCht1 transcript level in the larvae was observed upon the exposure of diflubenzuron. In contrast, exposures of the larvae to diflubenzuron resulted in the decreased chitin content. Furthermore, through a feeding-based RNA interference approach, we were able to reduce the PcCht1 transcript level by 59.7 % in the larvae, and consequently the treated larvae showed a very low molting rate compared with the control. Our results expanded the understanding of the important role of PcCht1 in the growth and development of P. citri.

  9. Preparing sternorrhynchous insects (Insecta: Hemiptera: Sternorrhyncha) for microscope examination: Hoyer’s mounting medium

    Science.gov (United States)

    Proper identification of aphids, scale insects, psyllids, and whitefles (Hemiptera: Sternorrhyncha) require preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare sternorrhynchous specimens on microscope slides for examination and identi...

  10. Preparing soft-bodied arthropods for arthropods for microscope examination: Armored Scales (Insects: Hemiptera: Diaspididae)

    Science.gov (United States)

    Proper identification of armored scales (Hemiptera: Diaspididae) requires preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare armored scales specimens on microscope slides for examination and identification. Steps ranging from collect...

  11. Preparing soft-bodied arthropods for microscope examination: Whiteflies (Insecta: Hemiptera: Alyrodidae)

    Science.gov (United States)

    Proper identification of whiteflies (Hemiptera:Alyrodidae) requires preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare whitefly specimens on microscope slides for examination and identification. Steps ranging from collection, specimen...

  12. Preparing soft-bodied arthropods for arthropods for microscope examination: Mealybugs (Insects: Hemiptera: Pseudococcidae)

    Science.gov (United States)

    Proper identification of mealybugs (Hemiptera: Pseudococcidae) require preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare mealybug specimens on microscope slides for examination and identification. Steps ranging from collection, spec...

  13. Preparing soft-bodied arthropods for microscope examination: Aphids (Insecta: Hemiptera: Aphididae)

    Science.gov (United States)

    Proper identification of aphids (Hemiptera: Aphididae) require preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare aphid specimens on microscope slides for examination and indentification. Steps ranging from collection, specimen clear...

  14. Variation in male and female genitalia among ten species of North American Anthocoris (Hemiptera: Heteroptera: Anthocoridae)

    Science.gov (United States)

    We compared morphology of internal reproductive anatomy and genitalia among 10 species of North American Anthocoris (Hemiptera: Heteroptera: Anthocoridae). Reproductive structures of males, including internal reproductive organs (testes, seminal vesicles, ejaculatory bulb, phallus), the left parame...

  15. Phylogenetic divergences of the true bugs (Insecta: Hemiptera: Heteroptera), with emphasis on the aquatic lineages

    DEFF Research Database (Denmark)

    Wang, Yan-hui; Cui, Ying; Rédei, Dávid;

    2016-01-01

    Heteroptera are among the most diverse hemimetabolous insects. Seven infraorders have been recognized within this suborder of Hemiptera. Apart from the well-established sister-group relationship between Cimicomorpha and Pentatomomorpha (= Terheteroptera), the two terminal lineages, the relationsh...

  16. Diaspididae (Hemiptera, Coccoidea in sori of two fern species

    Directory of Open Access Journals (Sweden)

    Marcelo Santos

    2015-12-01

    Duas Espécies de Cochonilhas (Hemiptera: Diaspididae Associadas com Soros de Samambaias Resumo. A presente comunicação relata a presença de duas espécies de cochonilhas Hemiberlesia palmae (Cockerell e Pinnaspis strachani (Cooley (Coccoidea, Diaspididae, associadas respectivamente com Asplenium serratum L. (Aspleniaceae e Niphidium crassifolium (L. Lellinger (Polypodiaceae. É o primeiro registro de uma samambaia como planta hospedeira de Hemiberlesia palmae.  Nas duas espécies de samambaias, os diaspidídeos encontravam-se concentrados principalmente ao redor dos soros.

  17. The complete mitochondrial genome of the citrus red mite Panonychus citri (Acari: Tetranychidae: high genome rearrangement and extremely truncated tRNAs

    Directory of Open Access Journals (Sweden)

    Dou Wei

    2010-10-01

    Full Text Available Abstract Background The family Tetranychidae (Chelicerata: Acari includes ~1200 species, many of which are of agronomic importance. To date, mitochondrial genomes of only two Tetranychidae species have been sequenced, and it has been found that these two mitochondrial genomes are characterized by many unusual features in genome organization and structure such as gene order and nucleotide frequency. The scarcity of available sequence data has greatly impeded evolutionary studies in Acari (mites and ticks. Information on Tetranychidae mitochondrial genomes is quite important for phylogenetic evaluation and population genetics, as well as the molecular evolution of functional genes such as acaricide-resistance genes. In this study, we sequenced the complete mitochondrial genome of Panonychus citri (Family Tetranychidae, a worldwide citrus pest, and provide a comparison to other Acari. Results The mitochondrial genome of P. citri is a typical circular molecule of 13,077 bp, and contains the complete set of 37 genes that are usually found in metazoans. This is the smallest mitochondrial genome within all sequenced Acari and other Chelicerata, primarily due to the significant size reduction of protein coding genes (PCGs, a large rRNA gene, and the A + T-rich region. The mitochondrial gene order for P. citri is the same as those for P. ulmi and Tetranychus urticae, but distinctly different from other Acari by a series of gene translocations and/or inversions. The majority of the P. citri mitochondrial genome has a high A + T content (85.28%, which is also reflected by AT-rich codons being used more frequently, but exhibits a positive GC-skew (0.03. The Acari mitochondrial nad1 exhibits a faster amino acid substitution rate than other genes, and the variation of nucleotide substitution patterns of PCGs is significantly correlated with the G + C content. Most tRNA genes of P. citri are extremely truncated and atypical (44-65, 54.1 ± 4.1 bp, lacking

  18. Biocontrol ability and putative mode of action of yeasts against Geotrichum citri-aurantii in citrus fruit.

    Science.gov (United States)

    Ferraz, Luriany Pompeo; Cunha, Tatiane da; da Silva, Aline Caroline; Kupper, Katia Cristina

    2016-01-01

    Sour rot is a major postharvest disease of citrus fruit and is caused by the fungal pathogen Geotrichum citri-aurantii. A lack of chemicals certified for the control of this disease has led to the consideration of alternative methods and strategies, such as the use of yeasts as biocontrol agents. The purpose of the present study was to test the ability of yeasts isolated from leaves, flowers, fruit, and soil, and six Saccharomyces cerevisiae isolates to control citrus sour rot, to assess the mechanisms of action of the yeast isolates that were demonstrated to be effective for biocontrol, and to identify the most effective yeast isolates for the biocontrol of G. citri-aurantii. In in vivo assays, three yeast isolates (ACBL-23, ACBL-44, and ACBL-77) showed a potential for controlling sour rot in citrus fruits, both preventatively and curatively. Most of the eight yeast isolates that were assessed for a mechanism of action did not produce antifungal compounds in an amount sufficient to inhibit the growth of the pathogen. Additionally, nutrient competition among the yeast strains was not found to be a biocontrol strategy. Instead, killer activity and hydrolytic enzyme production were identified as the major mechanisms involved in the biocontrol activity of the yeasts. Isolates ACBL-23, ACBL-44, and ACBL-77, which controlled sour rot most effectively, were identified as Rhodotorula minuta, Candida azyma, and Aureobasidium pullulans, respectively. To our knowledge, this is the first report of the potential of C. azyma as a biological control agent against a postharvest pathogen and its ability to produce a killer toxin.

  19. Molecular Characterization of Vitellogenin and Its Receptor Genes from Citrus Red Mite, Panonychus citri (McGregor

    Directory of Open Access Journals (Sweden)

    Rui Zhong

    2015-03-01

    Full Text Available The production and uptake of yolk protein play an important role in the reproduction of all oviparous organisms. Vitellogenin (Vg is the precursor of vitellin (Vn, which is the major egg storage protein, and vitellogenin receptor (VgR is a necessary protein for the uptake of Vg into developing oocytes. In this paper, we characterize the full-length Vg and VgR, PcVg1 and PcVgR, respectively, of the citrus red mite Panonychus citri (McGregor. The PcVg1 cDNA is 5748 nucleotides (nt with a 5553-nt open reading frame (ORF coding for 1851 amino acids (aa, and the PcVgR is 6090 nt, containing an intact ORF of 5673 nt coding an expected protein of 1891 aa. The PcVg1 aa sequence shows a typical GLCG domain and several K/RXXR cleavage sites, and PcVgR comprises two ligand-binding domains, two epidermal growth factor (EGF-like regions containing YWTD motifs, a transmembrane domain, and a cytoplasmic domain. An analysis of the aa sequences and phylogenetics implied that both genes were genetically distinct from those of ticks and insects. The transcriptional profiles determined by real-time quantitative PCR in different developmental stages showed that both genes present the same expressional tendencies in eggs, larvae, nymphs, and adults. This suggested that the biosynthesis and uptake of PcVg occurs coordinately. The strong reproductive capacity of P. citri has been hypothesized as an important factor in its resistance; consequently, understanding the molecular mechanisms regulating Vg and VgR are fundamental for mite control.

  20. Effects of soil-applied imidacloprid on Asian citrus psyllid (Hemiptera: Psyllidae) feeding behavior

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama is one of the most important pests of citrus due to its status as a vector of Candidatus Liberibacter asiaticus, the bacterium associated with huanglongbing (HLB) disease. The use of insecticides for vector control is the primary method of managing...

  1. Effect of silicon-based fertilizer applications on the reproduction and development of the citrus mealybug (Hemiptera: Pseudococcidae) feeding on green coleus.

    Science.gov (United States)

    Hogendorp, Brian K; Cloyd, Raymond A; Swiader, John M

    2009-12-01

    Mealybugs are major insect pests of greenhouses, interiorscapes, and conservatories because they feed on a wide-range of horticultural crops. Furthermore, mealybugs are difficult to regulate with insecticides due to the presence of a nearly impervious protective waxy covering, which means that alternative management strategies are required. As such, this study, involving two replicated experiments, was designed to determine the value of applying silicon-based fertilizers, as potassium silicate, to coleus, Solenstemon scutellarioides (L.) Codd, plants as a way to prevent outbreaks of the citrus mealybug, Planococcus citri (Risso) (Hemiptera: Pseudococcidae). The first experiment evaluated the effects of different application methods (foliar and drench), at 50 ppm silicon, using the commercially-available product, ProTek 0-0-3 The Silicon Solution. The second experiment entailed applying the silicon-based fertilizer as a drench to the growing medium at different rates (0, 100, 400, 800, and 1,600 ppm silicon). We determined the effects of the silicon-based fertilizer treatments on citrus mealybug life history parameters including number of eggs laid by the adult female, body size, and developmental time from first instar to ovipositing adult female. Furthermore, we used a plant alkaline fusion technique to assess the concentration (milligrams per kilogram or ppm) of silicon in the coleus plant tissues at variable time intervals (days). In general, this technique involved dry-ashing plant tissue in a muffle furnace, followed by alkaline fusion and then colormetric analysis. The silicon-based fertilizer application treatments, in both experiments, did not negatively affect any of the citrus mealybug life history parameters measured. In the first experiment, citrus mealybug female egg load ranged from 199.5 (drench application) to 219.4 (combination spray and drench application), and developmental time (days) from first instar crawler to ovipositing female ranged from

  2. Monitoramento da expressão gênica de Xanthomonas axonopodis pv. citri em diferentes condições ambientais

    OpenAIRE

    2003-01-01

    The bacterium Xanthomonas axonopodis pv. citri is a pathogen causing citric canker that compromises part of the orange production in the State of São Paulo, with negative consequences for the economy of the State and the Country. For the future control of citric canker, several investigators participated in the Xanthomonas Genome Project in order to determine the gene set of this bacterium and to contribute to the identification of the genes involved in its pathogenicity. In this respect, the...

  3. Exposure to Diflubenzuron Results in an Up-Regulation of a Chitin Synthase 1 Gene in Citrus Red Mite, Panonychus citri (Acari: Tetranychidae

    Directory of Open Access Journals (Sweden)

    Wen-Kai Xia

    2014-02-01

    Full Text Available Chitin synthase synthesizes chitin, which is critical for the arthropod exoskeleton. In this study, we cloned the cDNA sequences of a chitin synthase 1 gene, PcCHS1, in the citrus red mite, Panonychus citri (McGregor, which is one of the most economically important pests of citrus worldwide. The full-length cDNA of PcCHS1 contains an open reading frame of 4605 bp of nucleotides, which encodes a protein of 1535 amino acid residues with a predicted molecular mass of 175.0 kDa. A phylogenetic analysis showed that PcCHS1 was most closely related to CHS1 from Tetranychus urticae. During P. citri development, PcCHS1 was constantly expressed in all stages but highly expressed in the egg stage (114.8-fold higher than in the adult. When larvae were exposed to diflubenzuron (DFB for 6 h, the mite had a significantly high mortality rate, and the mRNA expression levels of PcCHS1 were significantly enhanced. These results indicate a promising use of DFB to control P. citri, by possibly acting as an inhibitor in chitin synthesis as indicated by the up-regulation of PcCHS1 after exposure to DFB.

  4. El género Apiococcus Hempel (Hemiptera, Eriococcidae, con redescripción de dos especies The genus Apiococcus Hempel (Hemiptera, Eriococcidae, with redescription of two species

    Directory of Open Access Journals (Sweden)

    Patricia González

    2013-03-01

    Full Text Available The genus Apiococcus Hempel (Hemiptera, Eriococcidae, with redescription of two species. Apiococcus Hempel is a genus from Brazil composed of four gall-inducing species. The adult females of two species, Apiococcus globosus Hempel and A. singularis Hempel, from Brazil, are redescribed and illustrated. Keys to the species of the genus and their galls are given.

  5. Do Scaphoideus titanus (Hemiptera: Cicadellidae) nymphs use vibrational communication?

    Science.gov (United States)

    Chuche, Julien; Thiéry, Denis; Mazzoni, Valerio

    2011-07-01

    Small Auchenorrhyncha use substrate-borne vibrations to communicate. Although this behaviour is well known in adult leafhoppers, so far no studies have been published on nymphs. Here we checked the occurrence of vibrational communication in Scaphoideus titanus (Hemiptera: Cicadellidae) nymphs as a possible explanation of their aggregative distributions on host plants. We studied possible vibratory emissions of isolated and grouped nymphs, as well as their behavioural responses to vibration stimuli that simulated presence of conspecifics, to disturbance noise, white noise and predator spiders. None of our synthetic stimuli or pre-recorded substrate vibrations from nymphs elicited specific vibration responses and only those due to grooming or mechanical contacts of the insect with the leaf were recorded. Thus, S. titanus nymphs showed to not use species-specific vibrations neither for intra- nor interspecific communication and also did not produce alarm vibrations when facing potential predators. We conclude that their aggregative behaviour is independent from a vibrational communication.

  6. Complete mitochondrial genome of Drabescoides nuchalis (Hemiptera: Cicadellidae).

    Science.gov (United States)

    Wu, Yunfei; Dai, Renhuai; Zhan, Hongping; Qu, Ling

    2016-09-01

    The complete mitochondrial genome (mitogenome) of Drabescoides nuchalis (Hemiptera: Cicadellidae) was sequenced. It is 15 309 bp in length with 75.62% (A + T) content and comprises 13 protein-coding genes, 22 transfer RNAs, two ribosomal RNA genes, and a non-coding region (GenBank accession no. KR349344). Gene order is identical to that of the inferred ancestral insect genome. All PCGs start with an ATN codon and terminate with TAA except ND4, which has an incomplete stop codon (T). The anticodons are identical to those of Drosophila yakuba. The phylogenetic tree confirms D. nuchalis and two Cicadellidae species are clustered into a clade, and Cicadellidae is a monophyletic group and provides support for the sister relationship of leafhopper and treehopper.

  7. Effects of irradiation on Planococcus minor (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Ravuiwasa, Kaliova Tavou; Lu, Kuang-Hui; Shen, Tse-Chi; Hwang, Shaw-Yhi

    2009-10-01

    Irradiation has been recognized and endorsed as a potential phytosanitary measure that could be an alternative to current quarantine treatments. Dosages of 50, 100, 150, 200, and 250 Gy were used to irradiate three different life stages (eggs, immatures, and adults) of Planococcus minor (Maskell) (Hemiptera: Pseudococcidae), focusing on females due to its parthenogenesis ability, with an aim to find the most tolerant stage and the most optimal dose to control P. minor. Cobalt 60 was the source of irradiation used. Irradiation of 150-250 Gy has a significant effect on all life stages of P. minor, decreasing its survival rate, percentage of adult reproduction, oviposition, and fertility rate. The adult was the most tolerant life stage in both mortality and fertility rate. All the different irradiated target life stage groups oviposited eggs, but none of the F2 eggs hatched at the most optimal dosage of 150-250 Gy.

  8. Scale Insects (Hemiptera: Coccoidea) on Myrciaria dubia (Myrtaceae) in Brazil.

    Science.gov (United States)

    Wolff, V R S; Kondo, T; Peronti, A L B G; Noronha, A C S

    2016-06-01

    Commercial cultivation of the fruit tree Myrciaria dubia (Myrtaceae) is being developed in Brazil but phytophagous insects, including scale insects (Hemiptera: Coccoidea), can become pests in plantations. The coccids Ceroplastes jamaicensis White, Coccus viridis (Green), Parasaissetia nigra (Nietner), Pseudokermes vitreus (Cockerell) (Coccidae), and the diaspidid Pseudaonidia trilobitiformis (Green) were collected on M. dubia in the municipality of Belém and Tomé-Açu, state of Pará (PA), metropolitan and Northeast Pará mesoregions, Brazil. A key to species of Coccoidea recorded on M. dubia, based on adult females, is provided. Photographs for all scale insects reported on M. dubia are provided. Ceroplastes jamaicensis is recorded for the first time for Brazil and is herein reported for the first time associated with this host.

  9. The complete mitochondrial genome of Bemisia afer (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Wang, Hua-Ling; Xiao, Na; Yang, Jiao; Wang, Xiao-Wei; Colvin, John; Liu, Shu-Sheng

    2016-01-01

    The length of the Bemisia afer (Priesner & Hosny) (Hemiptera: Aleyrodidae) mitochondrial genome (mitogenome) is 14,968 bp and consists of 13 protein coding genes (PCGs), 21 transfer RNAs (tRNA), 2 ribosomal RNAs and 1 control region. Apart from one serine transfer RNA gene (tRNA-Ser) which is absent, the synteny is consistent with the mitogenomes of other whitefly species. The overall base composition of the heavy strand for A, G, T and C is 28.96, 18.97, 36.7 and 15.37%, respectively, with a slight AT bias. Two rare codons (GTG and TTG) are employed as start codons by some PCGs. B. afer is a group of cryptic species. This first mitogenome cloned from African cassava B. afer, therefore, both enrich the whitefly molecular resource and will aid the sequencing of the other species' mitogenomes. It will contribute significantly to resolving the systematics of the B. afer complex.

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

    Science.gov (United States)

    Galdeano, Diogo Manzano; Breton, Michèle Claire; Lopes, João Roberto Spotti; Falk, Bryce W.

    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. PMID:28282380

  11. Construction of EGFP-labeling system for visualizing the infection process of Xanthomonas axonopodis pv. citri in planta.

    Science.gov (United States)

    Liu, Li-Ping; Deng, Zi-Niu; Qu, Jin-Wang; Yan, Jia-Wen; Catara, Vittoria; Li, Da-Zhi; Long, Gui-You; Li, Na

    2012-09-01

    Xanthomonas axonopodis pv. citri (Xac) is the causal agent of citrus bacterial canker, an economically important disease to world citrus industry. To monitor the infection process of Xac in different citrus plants, the enhanced green florescent protein (EGFP) visualizing system was constructed to visualize the propagation and localization in planta. First, the wild-type Xac was isolated from the diseased leaves of susceptible 'Bingtang' sweet orange, and then the isolated Xac was labeled with EGFP by triparental mating. After PCR identification, the growth kinetics and pathogenicity of the transformants were analyzed in comparison with the wild-type Xac. The EGFP-labeled bacteria were inoculated by spraying on the surface and infiltration in the mesophyll of 'Bingtang' sweet orange leaves. The bacterial cell multiplication and diffusion processes were observed directly under confocal laser scanning microscope at different intervals after inoculation. The results indicated that the EGFP-labeled Xac releasing clear green fluorescence light under fluorescent microscope showed the infection process and had the same pathogenicity as the wild type to citrus. Consequently, the labeled Xac demonstrated the ability as an efficient tool to monitor the pathogen infection.

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

    Science.gov (United States)

    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. PMID:28083006

  13. Developing detection and monitoring strategies for Planococcus minor (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Roda, Amy; Millar, Jocelyn G; Rascoe, John; Weihman, Scott; Stocks, Ian

    2012-12-01

    A pheromone-based system to locate and monitor Planococcus minor (Maskell), a pest of over 250 plants including citrus, grape, and cacao, was tested. The difficulty in distinguishing P. minor from the citrus mealybug, P. citri, makes finding and evaluating the impact of the pest challenging. Studies conducted in Puerto Rico determined that synthetic P. minor pheromone lures preaged 120 d in the field caught similar number of males as lures not aged (fresh). Molecular analysis of trapped mealybug males using mitochondrial cytochrome oxidase-1, the internal transcriber space two locus, and 28S-D2 gene showed the pheromone traps to be species specific. Traps baited with P. minor pheromone were used to monitor the pest in south Florida and to locate potential infestations. P. minor males were found at all locations studied in South Florida and were present in low numbers (1.03 +/- 0.69 mean +/- SE/trap/14 d). Over 14,000 terminals, fruit, and flowers were visually inspected over a 6 mo period of peak trap catches before the first adult P. minor female was found. The synthetic pheromone lures proved to be an effective tool to locate and monitor this pest new to the continental United States.

  14. The Effect of Ultraviolet-A Radiation Exposure on the Reproductive Ability, Longevity, and Development of the Dialeurodes citri (Homoptera: Aleyrodidae) F1 Generation.

    Science.gov (United States)

    Tariq, Kaleem; Noor, Mah; Saeed, Shafqat; Zhang, Hongyu

    2015-12-01

    Ultraviolet (UV) light has been used worldwide to monitor and trap insect pests. Whitefly adults show conspicuous positive phototactic behavior toward UV light stimuli; however, knowledge of the effect of UV light exposure on various life-history parameters of Dialeurodes citri remains limited. The present research aimed to investigate the effect of ultraviolet radiation (UV-A; long-wave) exposure on the reproduction and longevity of D. citri adults as well as the development of immature (eggs, larvae, and pupae) flies in the F1 generation. Paired D. citri adults were exposed to UV-A radiation for different periods (0, 1, 4, and 7 h/d) until the end of their life. The results of the experiment revealed that fecundity and oviposition rates increased when adults were irradiated for 1 and 4 h/d, but interestingly, both were significantly decreased compared with those of the controls after the longest exposure time (7 h/d). The longevity of adults of both sexes and the cumulative survival of F1 immatures were decreased with increased exposure time. Exposure to UV-A radiation prolonged the developmental time of immature stages, and a positive correlation was observed with exposure time. Exposure to UV light significantly inhibited egg hatching, larval development, pupation, and adult emergence. To the best of our knowledge, this is the first study describing the effect of UV radiation on a homopteran insect pest. This research may provide a foundation for the scientific community to use UV light in the field as an integrated pest management strategy to control this devastating agricultural pest.

  15. Effect of insect density and host plant quality on wing-form in Megamelus scutellaris (Hemiptera: Delphacidae)

    Science.gov (United States)

    Megamelus scutellaris Berg (Hemiptera: Delphacidae) is a South American species that feeds on waterhyacinth, Eichhornia crassipes Mart. (Solms). This species exhibits significant wing dimorphism whereby fully winged adults (macropters) are capable of flight while those with reduced wings (brachtypt...

  16. In silico identification of potential chaperone genes that belong to type III and type IV secretion systems in Xanthomonas axonopodis pv citri

    Directory of Open Access Journals (Sweden)

    Letícia Khater

    2005-01-01

    Full Text Available The secretion of bacterial virulence factors and flagellar components requires the assistance of specific type III and flagellar chaperones. Standard computational annotation of the genome of Xanthomonas axonopodis pv citri, a plant pathogen that causes citrus canker, initially did not identify any genes belonging to these chaperone categories since the primary sequence homology between them was very low. However, in a search for hypothetical proteins with characteristics similar to these chaperones, we have now identified 30 chromosomal and 10 plasmidial potential genes encoding chaperones belonging to types III/IV, and flagellar secretion systems in this organism. The significance of these findings is discussed.

  17. Identification of mealybug pest species (Hemiptera: Pseudococcidae) in Egypt and France, using a DNA barcoding approach.

    Science.gov (United States)

    Abd-Rabou, S; Shalaby, H; Germain, J-F; Ris, N; Kreiter, P; Malausa, T

    2012-10-01

    Pseudococcidae (mealybugs) is a large taxonomic group, including a number of agronomic pests. Taxonomic identification of mealybug species is a recurrent problem and represents a major barrier to the establishment of adequate pest management strategies. We combined molecular analysis of three DNA markers (28S-D2, cytochrome oxidase I and internal transcribed spacer 2) with morphological examination, for the identification of 176 specimens collected from 40 mealybug populations infesting various crops and ornamental plants in Egypt and France. This combination of DNA and morphological analyses led to the identification of 17 species: seven in Egypt (Planococcus citri (Risso), Planococcus ficus (Signoret), Maconellicoccus hirsutus (Green), Ferrisia virgata (Cockerell), Phenacoccus solenopsis Tinsley, Phenacoccus parvus Morrison and Saccharicoccus sacchari (Cockerell)) and 11 in France (Planococcus citri, Pseudococcus viburni Signoret, Pseudococcus longispinus (Targioni-Tozzetti), Pseudococcus comstocki (Kuwana), Rhizoecus amorphophalli Betrem, Trionymus bambusae (Green), Balanococcus diminutus (Leonardi), Phenacoccus madeirensis Green, Planococcus vovae (Nasonov), Dysmicoccus brevipes (Cockerell) and Phenacoccus aceris Signoret), Pl. citri being found in both countries. We also found genetic variation between populations considered to belong to the same species, justifying further investigation of the possible occurrence of complexes of cryptic taxa.

  18. Biologia e tabela de vida de fertilidade de Planococcus citri em diferentes estruturas vegetativas de cultivares de videira Biology and fertility life table of Planococcus citri in different vegetative structures of grape cultivars

    Directory of Open Access Journals (Sweden)

    Wilson José Morandi Filho

    2008-08-01

    Full Text Available O objetivo deste trabalho foi estudar a biologia e a tabela de vida de fertilidade de Planococcus citri, em folhas de videira das cultivares Cabernet Sauvignon, Itália e Isabel, em bagas de uva 'Itália' e em raízes da 'Isabel' e dos porta-enxertos 101-14 e IAC-572. Os seguintes parâmetros foram avaliados: duração e viabilidade dos estágios de ovo e ninfa; e fecundidade e longevidade dos adultos. Em raízes do porta-enxerto IAC-572, a cochonilha não completou o ciclo biológico. Em bagas de uva 'Itália', o inseto completou a fase de ninfa, porém os adultos foram inférteis. Em folhas das diferentes cultivares, a duração média do período de ovo a adulto dos machos foi de 24,63 dias, com viabilidade de 32%, enquanto as fêmeas duraram 32 dias com viabilidade de 56%. Em raízes, a duração do ciclo biológico de fêmeas e machos foi de 32,45 e 29,50 dias, respectivamente. Em folhas, a fecundidade foi de 67,27, 66,09 e 53,33 ovos por fêmea, nas cultivares Cabernet Sauvignon, Isabel e Itália, respectivamente. Nas raízes foram obtidos 30,4 e 70,0 ovos por fêmea, no porta-enxerto 101-14 e na cultivar Isabel, respectivamente.The objective of this work was to study the biology and fertility life table of Planococcus citri in leaves of the grape cultivars Cabernet Sauvignon, Itália and Isabel, in berries of 'Itália', in roots of 'Isabel' and 101-14 and IAC-572 rootstocks. The following parameters were evaluated: duration and viability of the egg and nymph stages; and fertility and longevity of the adults. On berries of 'Itália', the insect completed the nymph phase, however the adults were infertile. On roots of the rootstock IAC-572, citrus mealybug was unable to develop. On leaves of the grape cultivars, the period of egg to adult males was 24.63 days, with viability of 32%, while females lasted 32 days with viability of 56%. On roots, the duration of the cycle of females and males was 32.45 and 29.50 days, respectively. For females

  19. Inventory and assessment of foliar natural enemies of the soybean aphid (Hemiptera: Aphididae) in South Dakota

    Science.gov (United States)

    Soybean aphid (Aphis glycines Matsumura) (Hemiptera: Aphididae) is a major pest of soybean in northern production regions of North America, and insecticides have been the primary management approach while alternative methods are developed. Knowledge of arthropod natural enemies and their impact on ...

  20. Preparing soft-bodied arthropods for microscope examination: Soft Scales (Insecta: Hemiptera: Coccidae)

    Science.gov (United States)

    Proper identification of soft scales (Hemiptera:Coccidae) requires preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare soft scale specimens on microscope slides for examination and identification. Steps ranging from collection, speci...

  1. Micro-CT study of the anatomy of the Leafhopper Homalodisca vitripennis (Hemiptera: Cicadellidae)

    Science.gov (United States)

    A Digital Anatomy Library, DAL, was produced to the anatomy of the glassy-winged sharpshooter adult, Homalodisca vitripennis (Hemiptera: Cicadellidae), vector of bacteria which cause Pierce’s disease of grapevines. The insect anatomy was elucidated using a high resolution Bruker Skyscan 1172 micro t...

  2. Contributions to the knowledge of Banasa Stål (Hemiptera, Heteroptera, Pentatomidae: Banasa chaca Thomas

    Directory of Open Access Journals (Sweden)

    Thereza de Almeida Garbelotto

    2011-09-01

    Full Text Available Contributions to the knowledge of Banasa Stål (Hemiptera, Heteroptera, Pentatomidae: Banasa chaca Thomas. The male of Banasa chaca Thomas is described with emphasis on external and internal genitalia and the female internal genitalia is described. Banasa chaca is newly recorded from Buenos Aires Province (Argentina.

  3. A redescription of the endemic Madagascan genus Tricompastes (Hemiptera: Heteroptera: Pentatomidae).

    Science.gov (United States)

    Kment, Petr; Baena, Manuel

    2015-11-17

    The endemic Madagascan genus Tricompastes Cachan, 1952 (Hemiptera: Heteroptera: Pentatomidae: Pentatominae: Triplatygini), containing a single species-Tricompastes gigas Cachan, 1952, is redescribed and illustrated, including first descriptions of male and female genitalia. First exact localities of the species are provided. Lectotype of T. gigas is designated.

  4. Effects of founder population size on the performance of Orius laevigatus (Hemiptera: Anthocoridae) colonies

    NARCIS (Netherlands)

    Castañe, C.; Bueno, V.H.P.; Carvalho, L.M.; Lenteren, van J.C.

    2014-01-01

    Orius laevigatus (Hemiptera: Anthocoridae) is a key predator of thrips and is mass reared in large numbers for use in biological control. The aim of this study was to evaluate the effect of founder population size on the biological and behavioral performance of O. laevigatus over time. Laboratory li

  5. Use of pheromones for monitoring phytophagous stink bug (Hemiptera: Pentatomidae) populations

    Science.gov (United States)

    Phytophagous native stink bugs (Hemiptera: Pentatomidae), including Euschistus spp., Nezara viridula (L.), Chinavia hilaris (Say), Plautia stali Scott, Chlorochroa spp., and Thyanta spp., are primary pests responsible for millions of dollars in losses and cost of control in most fruit, vegetable, gr...

  6. Field evaluation of potential pheromone lures for Lygus lineolaris (Hemiptera: Miridae) in the Mid-South

    Science.gov (United States)

    Plant bugs (Hemiptera: Miridae) are phytophagous pests of cultivated plants around the world. In the mid-South region of the United States, Lygus lineolaris is a primary pest of cotton, and causes economic damage. Previously published research about the volatiles produced by members of the genus Lyg...

  7. Attraction of stink bug (Hemiptera: Pentatomidae) nymphs to Euschistus aggregation pheromone in the field

    Science.gov (United States)

    Phytophagous stink bugs (Hemiptera: Pentatomidae) are primary pests in most fruit, vegetable, grain, and row crops worldwide. Pheromones have been identified and synthesized for several species of economically important stink bug pests. When yellow pyramid traps are baited with lures containing thes...

  8. Phylogenetics and evolutionary morphology of the Neotropical true bug genus Epipolops (Hemiptera: Heteroptera: Geocoridae)

    Science.gov (United States)

    Species of Epipolops Herrich-Schaeffer (Hemiptera: Geocoridae), comprising the largest genus of Pamphantinae, are among the most bizarre true bugs because of their striking morphology. To elucidate evolutionary morphology in Epipolops, a phylogenetic analysis was performed using 17 species and 36 ad...

  9. Description of a new coccid (Hemiptera, Coccidae on avocado (Persea americana Mill. from Colombia, South America

    Directory of Open Access Journals (Sweden)

    Takumasa Kondo

    2010-04-01

    Full Text Available A new soft scale insect, Bombacoccus aguacatae Kondo, gen. n. and sp. n. (Hemiptera: Coccidae collected on the branches and twigs of avocado, Persea americana Mill. (Lauraceae in Colombia, is described and illustrated based on the adult female. An updated taxonomic key to closely related genera of the Toumeyella-group is provided.

  10. Gut content analysis of a phloem-feeding insect, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae)

    Science.gov (United States)

    Potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae) is a key pest of potato (Solanum tuberosum L., Solanales: Solanaceae) and a vector of "Candidatus Liberibacter solanacearum," the pathogen associated with zebra chip disease. In addition to its presence on cultivated crops, the p...

  11. First record of Eggplant Mealybug, Coccidohystrix insolita (Hemiptera: Pseudococcidae, on Guam: Potentially a major pest

    Directory of Open Access Journals (Sweden)

    Aubrey Moore

    2014-01-01

    Full Text Available The eggplant mealybug, Coccidohystrix insolita (Green (Hemiptera: Pseudococcidae, is recorded from the island of Guam in the Mariana Islands for the first time. Factors indicating that this introduced mealybug has the potential to become a pest of economic importance for agriculture and horticulture on Guam are discussed.

  12. DNA markers to disentangle complexes of cryptic taxa in mealybugs (Hemiptera: Pseudococcidae)

    Science.gov (United States)

    Mealybugs (Hemiptera: Pseudococcidae) are major pests of a wide range of crops and ornamental plants worldwide. Their high degree of morphological similarity makes them difficult to identify and limits their study and management. We aimed to identify a set of markers for the genetic characterization...

  13. Genes expressed in field-caught pink hibiscus mealybugs, Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae)

    Science.gov (United States)

    We advanced the understanding of the biology of an invasive pest, the pink hibiscus mealybug, PHM, Maconellicoccus hirsutus (Hemiptera: Pseudococcidae) by using a genomics approach to identify genes expressed within field collected PHM. The information produced provides valuable, new and unique info...

  14. First record of Eggplant Mealybug, Coccidohystrixinsolita (Hemiptera: Pseudococcidae), on Guam: Potentially a major pest.

    Science.gov (United States)

    Moore, Aubrey; Watson, Gillian W; Bamba, Jesse

    2014-01-01

    The eggplant mealybug, Coccidohystrixinsolita (Green) (Hemiptera: Pseudococcidae), is recorded from the island of Guam in the Mariana Islands for the first time. Factors indicating that this introduced mealybug has the potential to become a pest of economic importance for agriculture and horticulture on Guam are discussed.

  15. Proteins expressed in the pink hibiscus mealybug, Maconellicoccus hirsutus (Hemiptera: Pseudococcidae)

    Science.gov (United States)

    We produced a dataset of 315 protein sequences which we isolated from the pink hibiscus mealybug, PHM, Maconellicoccus hirsutus (Hemiptera: Pseudococcidae). The dataset was published under accession numbers: EF070444-EF070605 and EF092085-EF091933, in the National Center for Biotechnology Informatio...

  16. Wolbachia infection differs among divergent mitochondrial haplotypes of Bactericera cockerelli (Hemiptera: Triozidae)

    Science.gov (United States)

    Four mitochondrial (cytrochrome oxidase I) haplotypes of the potato psyllid, Bactericera cockerelli (S'ulc) (Hemiptera: Triozidae), have been identified in North America: western, central, northwestern,and southwestern. A recent study found that females of the northwestern haplotype mated by males o...

  17. Phylogeographic analysis of Harrisia cactus mealybug, Hypogeococcus pungens (Hemiptera: Pseudoccidae) populations: work in progress

    Science.gov (United States)

    Harrisia cactus mealybug (HCM), Hypogeococcus pungens (Hemiptera: Pseudoccidae) Granara de Willink (1981) is infesting and killing cacti in the southern coast of Puerto Rico, covering an area of about 1,400 km2. The 13 species of cacti occurring in Puerto Rico are threatened by this new pest; three...

  18. Resistance for watermelon (Citrullus lanatus var. lanatus) against whiteflies (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is an important global pest with and an extensive host range. Watermelon (Citrullus lanatus var. lanatus) is among the crops damaged by this pest. Host plant resistance is the foundation for the management of crops pests in general. ...

  19. Preliminary Observations on Zelus obscuridorsis (Stål) (Hemiptera: Reduviidae) as Predator of the Corn Leafhopper (Hemiptera: Cicadellidae) in Argentina.

    Science.gov (United States)

    Virla, Eduardo G; Melo, Cecilia M; Speranza, Stefano

    2015-06-03

    The corn leafhopper Dalbulus maidis (Hemiptera: Cicadellidae), is an important corn pest in most of tropical and subtropical America. This leafhopper has a rich natural enemy complex of which parasitoids and pathogens are the most studied; knowledge on its predators is limited. We noted the presence of the native assassin bug Zelus obscuridorsis (Hemiptera: Reduviidae) predating diverse motile insects, including the corn leafhopper, on corn plants cultivated in household vegetable gardens in San Miguel de Tucumán (Argentina); in order to verify its predatory actions, we exposed lab-bred individuals of D. maidis to adults of Z. obscuridorsis. The predators were starved for 24 h before trials in which the corn leafhopper in different developmental stages were exposed. Zelus obscuridorsis is highly skilled in catching specimens in motion, but it was not able to prey on eggs. The predator was capable to catch and prey on nymphs and adults.

  20. Preliminary Observations on Zelus obscuridorsis (Stål (Hemiptera: Reduviidae as Predator of the Corn Leafhopper (Hemiptera: Cicadellidae in Argentina

    Directory of Open Access Journals (Sweden)

    Eduardo G. Virla

    2015-06-01

    Full Text Available The corn leafhopper Dalbulus maidis (Hemiptera: Cicadellidae, is an important corn pest in most of tropical and subtropical America. This leafhopper has a rich natural enemy complex of which parasitoids and pathogens are the most studied; knowledge on its predators is limited. We noted the presence of the native assassin bug Zelus obscuridorsis (Hemiptera: Reduviidae predating diverse motile insects, including the corn leafhopper, on corn plants cultivated in household vegetable gardens in San Miguel de Tucumán (Argentina; in order to verify its predatory actions, we exposed lab-bred individuals of D. maidis to adults of Z. obscuridorsis. The predators were starved for 24 h before trials in which the corn leafhopper in different developmental stages were exposed. Zelus obscuridorsis is highly skilled in catching specimens in motion, but it was not able to prey on eggs. The predator was capable to catch and prey on nymphs and adults.

  1. Use of molecular tools for the identification of males of some scale insects (Hemiptera: Coccoidea, in pheromone traps used for monitoring and comparison with females

    Directory of Open Access Journals (Sweden)

    István Tóbiás

    2010-11-01

    Full Text Available Species from Pseudococcidae family were studied. It was determined that the dry males of Planococcus citri, and Pseudococcus comstocki, collected by pheromone traps could be useful for the molecular analyses too. The ITS-2 sequences of males and females in case of Pl.citri, Planococcus ficus and Ps. comstocki were identical. This molecular method could differentiate the two mealybug species and this method can be useful to have idea specimens collected by pheromone traps.

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

    Directory of Open Access Journals (Sweden)

    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

  3. Genome-wide mutagenesis of Xanthomonas axonopodis pv. citri reveals novel genetic determinants and regulation mechanisms of biofilm formation.

    Directory of Open Access Journals (Sweden)

    Jinyun Li

    Full Text Available Xanthomonas axonopodis pv. citri (Xac causes citrus canker disease, a major threat to citrus production worldwide. Accumulating evidence suggests that the formation of biofilms on citrus leaves plays an important role in the epiphytic survival of this pathogen prior to the development of canker disease. However, the process of Xac biofilm formation is poorly understood. Here, we report a genome-scale study of Xac biofilm formation in which we identified 92 genes, including 33 novel genes involved in biofilm formation and 7 previously characterized genes, colR, fhaB, fliC, galU, gumD, wxacO, and rbfC, known to be important for Xac biofilm formation. In addition, 52 other genes with defined or putative functions in biofilm formation were identified, even though they had not previously reported been to be associated with biofilm formation. The 92 genes were isolated from 292 biofilm-defective mutants following a screen of a transposon insertion library containing 22,000 Xac strain 306 mutants. Further analyses indicated that 16 of the novel genes are involved in the production of extracellular polysaccharide (EPS and/or lipopolysaccharide (LPS, 7 genes are involved in signaling and regulatory pathways, and 5 genes have unknown roles in biofilm formation. Furthermore, two novel genes, XAC0482, encoding a haloacid dehalogenase-like phosphatase, and XAC0494 (designated as rbfS, encoding a two-component sensor protein, were confirmed to be biofilm-related genes through complementation assays. Our data demonstrate that the formation of mature biofilm requires EPS, LPS, both flagellum-dependent and flagellum-independent cell motility, secreted proteins and extracellular DNA. Additionally, multiple signaling pathways are involved in Xac biofilm formation. This work is the first report on a genome-wide scale of the genetic processes of biofilm formation in plant pathogenic bacteria. The report provides significant new information about the genetic

  4. Effects of temperature on population growth parameters of Cryptolaemus montrouzieri (Coleoptera: Coccinellidae reared on Planococcus citri (Homoptera: Pseudococcidae

    Directory of Open Access Journals (Sweden)

    Negar Saeedi

    2015-09-01

    Full Text Available The effect of temperature on the development, survival, fecundity and population growth parameters of Cryptolaemus montrouzieri Mulsant (Col.: Coccinellidae reared on Planococcus citri Risso (Hom.: Pseudococcidae was determined at five constant temperatures (18, 22, 26, 30 and 32±1°C in the laboratory conditions. Results showed a temperature - dependent development of the coccinellid. The mean total of immature period was estimated 76.6±0.9, 33.9±0.1, 25.8±0.1, 22.6±0.1 and 26.2±1.4 days at 18, 22, 26, 30 and 32°C, respectively. The highest and lowest values of R0, rm and λ were obtained 369.9±50.2 and 2.5±0.8 (female/female/generation, 0.07±0.01 and 0.02±0.01 (female/female/day and 1.08±0.01 and 1.02±0.01 (day-1 at 26 and 32°C, respectively. The lowest values of generation time (T and doubling time (Dt were calculated 42.2±0.9 and 8.9±0.5 days at 32 and 26°C, respectively. The lower and higher developmental threshold of total of immature period were obtained 11.5 and 25.5°C, respectively. The thermal requirement for completion of total of immature period of this predator were estimated 400 DD. These results showed that 26°C and/or adjacent temperature is most suitable for mass rearing of this predator.

  5. Assessment of Prey Preference by the Generalist Predator, Mallada basalis (Walker), When Offered Two Species of Spider Mites, Tetranychus kanzawai Kishida and Panonychus citri (McGregor) on Papaya

    Science.gov (United States)

    We investigated potential prey preference of the generalist predator Mallada basalis (Walker) when offered two mites, Tetranychus kanzawai Kishida and Panonychus citri (McGregor), both important pests on papaya. Laboratory choice tests revealed that none of the three larval instars of M. basalis sho...

  6. Megamelus bellicus (Hemiptera: Delphacidae: immature stages and biology Megamelus bellicus (Hemiptera: Delphacidae: estados inmaduros y biología

    Directory of Open Access Journals (Sweden)

    Roxana Mariani

    2007-12-01

    Full Text Available The immature stages of Megamelus bellicus Remes Lenicov & Sosa (Hemiptera: Delphacidae are described, keyed and illustrated. The description of each stage was based on 24-h hatched nymphs from the laboratory colony. The main characters that distinguish the various stages are: body size, color, number of tarsomeres, espinulation of the metatibia and number of teeth on the spur; presence of sensoria on antennal pedicel. This insect was reared on pieces of water hyacinth, Eichhornia crassipes (Martius Solms Laubach. Biological data based on lab and field observations show that M. bellicus carries out its biological cycle successfully on Pontederiaceae. One to nine eggs per scar are laid deeply into the aerenquima of the petiole, being most frequent 3-4, less frequent 5, 2 and 6 and rarely 1, 7 and 9. Eulophid wasps Aprostocetus (Ootetrastichus sp, known as eggs parasitoid, was registered and quantified. As M. bellicus occupies the same ecological habitat that M. scutellaris Berg, we highlighted some morphological and biological aspects that allow their differentiation.Se describen e ilustran los estados inmaduros de Megamelus bellicus Remes Lenicov & Sosa (Hemiptera: Delphacidae y se presenta una clave para identificarlos. La descripción de cada estadio se realizó sobre la base de ninfas extraidas 24 horas posteriores a la eclosión, de colonias de laboratorio y criadas sobre trozos de hojas de camalote Eichhornia crassipes (Martius Solms Laubach. Los principales caracteres para distinguir los distintos estadios son: tamaño del cuerpo, color, número de tarsómeros, espinulación de la metatibia y número de dientes del calcar y presencia de sensorios en el pedicelo antenal. Datos biológicos basados en observaciones en el laboratorio y en el campo, muestran que M. bellicus realiza su ciclo biológico exitosamente sobre Pontederiaceae. Los huevos, dispuestos de 1 a 9 por postura, son colocados profundamente en el aerénquima del pecíolo; son m

  7. Characterization and functional analysis of a novel glutathione S-transferase gene potentially associated with the abamectin resistance in Panonychus citri (McGregor).

    Science.gov (United States)

    Liao, Chong-Yu; Xia, Wen-Kai; Feng, Ying-Cai; Li, Gang; Liu, Hai; Dou, Wei; Wang, Jin-Jun

    2016-09-01

    The citrus red mite, Panonychus citri (McGregor), a major citrus pest distributed worldwide, has been found to be resistant to various insecticides and acaricides used in China. However, the molecular mechanisms associated with the abamectin resistance in this species have not yet been reported. In this study, results showed over-expression of a novel glutathione S-transferases (GSTs) gene (PcGSTm5) in abamectin-resistant P. citri. Quantitative real-time PCR analysis showed that the transcripts of PcGSTm5 were also significantly up-regulated after exposure to abamectin and the maximum mRNA expression level at nymphal stage. The recombinant protein of PcGSTm5-pET-28a produced by Escherichia coli showed a pronounced activity toward the conjugates of 1-chloro-2,4 dinitrobenzene (CDNB) and glutathione (GSH). The kinetics of CDNB and GSH and its optimal pH and thermal stability were also determined. Reverse genetic study through a new method of leaf-mediated dsRNA feeding further support a link between the expression of PcGSTm5 and abamectin resistance. However, no direct evidence was found in metabolism or inhibition assays to confirm the hypothesis that PcGSTm5 can metabolize abamectin. Finally, it is here speculated that PcGSTm5 may play a role in abamectin detoxification through other pathway such as the antioxidant protection.

  8. Exploration for facultative endosymbionts of glassy-wingedsharpshooter (Hemiptera: Cicadellidae)

    Energy Technology Data Exchange (ETDEWEB)

    Montllor-Curley, C.; Brodie, E.L.; Lechner, M.G.; Purcell, A.H.

    2006-07-01

    Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae),glassy-winged sharpshooter, was collected in California and severalstates in the southeastern United States in 2002 and 2003 and analyzedfor endosymbiotic bacteria. Hemolymph, eggs, and bacteriomes wereexamined for the presence of bacteria by polymerase chain reaction. Asubset of hemolymph and egg samples had their 16S rRNA gene ampliconscloned and sequenced or analyzed by restriction digest patterns ofsamples compared with known bacterial DNA. Baumannia cicadellinicola, oneof the primary symbionts of glassy-winged sharpshooter, was found in themajority of hemolymph samples, although it has been considered until nowto reside primarily inside the specialized host bacteriocytes. Wolbachiasp., a common secondary symbiont in many insect taxa investigated todate, was the second most frequently detected bacterium in hemolymphsamples. In addition, we detected bacteria that were most closely related(by 16S rRNA gene sequence) to Pseudomonas, Stenotrophomonas, andAcinetobacter in hemolymph samples of one and/or two glassy-wingedsharpshooters, but their origin is uncertain.

  9. Egg parasitoids of Megamelus spp. (Hemiptera: Delphacidae in Argentina

    Directory of Open Access Journals (Sweden)

    Serguei V. TRIAPITSYN

    2010-01-01

    Full Text Available Se revisaron los parasitoides oófagos (Hymenoptera: Eulophidae, Mymaridae, y Platygastridae de Megamelus spp. (Hemiptera: Delphacidae de la Argentina, y se presenta una clave para su identificación. Se describen cuatro especies nuevas: Anagrus (Anagrus empanadus Triapitsyn, sp. nov. (Mymaridae, parasitoide de M. scutellaris Berg que se alimenta de camalote, Eichhornia crassipes (Martius Solms-Laubach; Aprostocetus (Ootetrastichus riverplaticus Triapitsyn, sp. nov. (Eulophidae: Tetrastichinae, parasitoide de M. bellicus Marino de Remes Lenicov & Sosa; A. (Ootetrastichus yerbamatei Triapitsyn, sp. nov. (parasitoide de M. bellicus, M. scutellaris y Megamelus sp., todos de la provincia de Buenos Aires (A. (Ootetrastichus yerbamatei también se encuentra en Formosa; y Parascelio sabcli Triapitsyn, sp. nov. (Platygastridae: Scelioninae, parasitoide de M. scutellaris en Formosa, la asociación con el huésped es tentativa. Se incluyen otros parasitoides oófagos conocidos de Megamelus spp. en la Argentina, tales como Kalopolynema (Kalopolynema poema Triapitsyn & Berezovskiy (Mymaridae, parasitoide de M. scutellaris en Buenos Aires y también Cremastobaeus atratus Loiácono & Mulvani (Platygastridae: Scelioninae, parasitoide de M. scutellaris en Formosa, la asociación con el huésped es tentativa.

  10. How will Mahanarva spectabilis (Hemiptera: Cercopidae) Respond to Global Warming?

    Science.gov (United States)

    Fonseca, M G; Auad, A M; Resende, T T; Hott, M C; Borges, C A V

    2016-01-01

    The aim of this study was to determine the favorable constant temperature range for Mahanarva spectabilis(Distant) (Hemiptera: Cercopidae) development as well as to generate geographic distribution maps of this insect pest for future climate scenarios. M. spectabilis eggs were reared on two host plants (Brachiaria ruziziensis(Germain and Edvard) and Pennisetum purpureum(Schumach)), with individual plants kept at temperatures of 16, 20, 24, 28, and 32 °C. Nymphal stage duration, nymphal survival, adult longevity, and egg production were recorded for each temperature*host plant combination. Using the favorable temperature ranges for M. spectabilis development, it was possible to generate geographic distribution. Nymphal survival was highest at 24.4 °C, with estimates of 44 and 8% on Pennisetum and Brachiaria, respectively. Nymphal stage duration was greater on Brachiaria than on Pennisetum at 20 and 24 °C but equal at 28 °C. Egg production was higher on Pennisetum at 24 and 28 °C than at 20 °C, and adult longevity on Pennisetum was higher at 28 °C than at 20 °C, whereas adult longevity at 24 °C did not differ from that at 20 and 28 °C. With these results, it was possible to predict a reduction in M. spectabilis densities in most regions of Brazil in future climate scenarios.

  11. Jurassic Progonocimicidae (Hemiptera) from China and phylogenetic evolution of Coleorrhyncha

    Institute of Scientific and Technical Information of China (English)

    SZWEDO; Jacek

    2009-01-01

    The fossil record of Progonocimicidae of Hemiptera suborder Coleorrhyncha from China is reviewed. Ovicimex laiyangensis Hong et Wang, 1990, from the Lower Cretaceous of Laiyang, is excluded from Coleorrhyncha. The available generic name Mesocimex Hong, 1983 is resurrected from synonymy and proposed for replacement of the preoccupied name and junior homonym Mesoscytina Hong, 1983, non Mesoscytina Tillyard, 1919. It resulted in following new combinations: Mesocimex abditus (Yu. Popov, 1982) comb. n., Mesocimex ambiguus (Yu. Popov, 1985) comb. n., Mesocimex brunneus (Hong, 1983), comb. n., Mesocimex fidus (Yu. Popov, 1982) comb. n., Mesocimex intermedius (Yu. Popov, 1985) comb. n., Mesocimex kuzbasicus (Yu. Popov, 1985) comb. n., Mesocimex liliputus (Yu. Popov, 1988) comb. n., Mesocimex minutus (Yu. Popov, 1982) comb. n., Mesocimex modestus (Yu. Popov, 1985) comb. n., Mesocimex paulinus (Yu. Popov, 1982) comb. n., Mesocimex cognatus (Yu. Popov, 1982) comb. n. An annotated list of species of Mesocimex is given. In addition, a new species, Mesocimex lini sp. nov., is described based on well-preserved specimens with wings and bodies from the Middle Jurassic of Daohugou, China. This discovery supports the Middle Jurassic age of Daohugou Lagerstatte, since all species of Mesocimex are confined to the Lower-Middle Jurassic. The phylogenetic evolution of Coleorrhyncha is discussed: Cicadocorinae, Karabasiinae, Hoploridiinae, and Peloridiidae are monophyletic clades whereas Progonocimicinae and Karabasidae are clearly paraphyletic groups.

  12. Application of RNA interference in triatomine(Hemiptera:Reduviidae)studies

    Institute of Scientific and Technical Information of China (English)

    Rafaela M.M.Paim; Ricardo N.Araujo; Michael J.Lehane; Nelder F.Gontijo; Marcos H.Pereira

    2013-01-01

    Triatomines(Hemiptera: Reduviidae)are obligate hematophagous insects.They are of medical importance because they are vectors of Trypanosoma cruzi,the causative agent of Chagas disease in the Americas.In recent years,the RNA interference (RNAi)technology has emerged as a practical and useful alternative means of studying gene function in insects,including triatomine bugs.RNAi research in triatomines is still in its early stages,several issues still need to be elucidated,including the description of the molecules involved in the RNAi machinery and aspects related to phenotype evaluation and persistence of the knockdown in different tissues and organs.This review considers recent applications of RNAi to triatomine research,describing the major methods that have been applied during the knockdown process such as the double-stranded RNA delivery mechanism(injection,microinjection,or ingestion)and the phenotype characterization (mRNA and target protein levels)in studies conducted with the intent to provide greater insights into the biology of these insects.In addition to the characterization of insect biomolecules,some with biopharmacological potential,RNAi may provide a new view of the interaction between triatomine and trypanosomatids,enabling the development of new measures for vector control and transmission of the parasite.

  13. Weed hosts of cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Vennila, S; Prasad, Y G; Prabhakar, M; Agarwal, Meenu; Sreedevi, G; Bambawale, O M

    2013-03-01

    The exotic cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) invaded India during 2006, and caused widespread infestation across all nine cotton growing states. P. solenopsis also infested weeds that aided its faster spread and increased severity across cotton fields. Two year survey carried out to document host plants of P. solenopsis between 2008 and 2010 revealed 27, 83, 59 and 108 weeds belonging to 8, 18, 10 and 32 families serving as alternate hosts at North, Central, South and All India cotton growing zones, respectively. Plant species of four families viz., Asteraceae, Amaranthaceae, Malvaceae and Lamiaceae constituted almost 50% of the weed hosts. While 39 weed species supported P. solenopsis multiplication during the cotton season, 37 were hosts during off season. Higher number of weeds as off season hosts (17) outnumbering cotton season (13) at Central over other zones indicated the strong carryover of the pest aided by weeds between two cotton seasons. Six, two and seven weed hosts had the extreme severity of Grade 4 during cotton, off and cotton + off seasons, respectively. Higher number of weed hosts of P. solenopsis were located at roadside: South (12) > Central (8) > North (3) zones. Commonality of weed hosts was higher between C+S zones, while no weed host was common between N+S zones. Paper furnishes the wide range of weed hosts of P. solenopsis, discusses their significance, and formulated general and specific cultural management strategies for nationwide implementation to prevent its outbreaks.

  14. The scale insects (Hemiptera: Coccoidea) of the Maltese Archipelago.

    Science.gov (United States)

    Mifsud, David; Mazzeo, Gaetana; Russo, Agatino; Watson, Gillian W

    2014-09-25

    Past works on scale insects (Hemiptera: Coccoidea) from the Maltese Archipelago are reviewed. Based on the literature and contemporary collections, a total of 93 species of scale insects belonging to 12 scale insect families are here reported (Aclerdidae 1 species; Asterolecaniidae 4; Coccidae 17; Diaspididae 46; Eriococcidae 5; Kermesidae 1; Margarodidae 1; Micrococcidae 1; Monophlebidae 2; Pseudoccocidae 11; Putoidae 2 and Rhizoecidae 2). Of these, 17 species represent new distribution records. Ten species are excluded from the scale insect fauna of the Maltese Islands. Of the 93 species present, only 29 (31.18%) are probably indigenous and the rest (68.82%) represent established introductions from elsewhere. More than 65% of the indigenous species are typical Mediterranean in distribution, with a few species having a mainly European chorotype. A quarter of the established aliens originate from Eurasia, followed by an East Asian/ Oriental component (20.31%); European (14.06%); Neotropical (14.06%); cryptogenic (14.06%); African (7.81%) and Australasian (4.70%). Movement of live fruit trees and ornamental plants into the Maltese Archipelago from nearby countries is probably the main route for entry of alien scale insects into the country. Some possible future introductions are discussed.

  15. Systematics of Mepraia (Hemiptera-Reduviidae): cytogenetic and molecular variation.

    Science.gov (United States)

    Calleros, L; Panzera, F; Bargues, M D; Monteiro, F A; Klisiowicz, D R; Zuriaga, M A; Mas-Coma, S; Pérez, R

    2010-03-01

    The haematophagous insects of the subfamily Triatominae (Hemiptera-Reduviidae) have great epidemiological importance as vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Mepraia was originally described as a monotypic genus comprised of Mepraia spinolai, distributed along coastal areas of northern Chile (from Region I to the Metropolitan Region). Recently, some M. spinolai populations have been ranked as a new species named Mepraia gajardoi. Several populations along the distribution range of the genus were sampled, and genetic differentiation was studied based upon the analysis of three molecular markers: cytogenetics (karyotype and chromosome behaviour during meiosis using the C-banding technique), mitochondrial DNA (a cytochrome oxidase I gene fragment), and nuclear ribosomal DNA (intergenic region including the two internal transcribed spacers ITS-1 and ITS-2 and the 5.8S rRNA gene). The data here presented indicate that populations within the Mepraia genus (excluding Region II specimens) can be divided into two separate lineages. One lineage is comprised of specimens from the northernmost Region I and represents M. gajardoi. The other includes samples from the southern III, IV and the Metropolitan Regions, and represents M. spinolai. Region II individuals deserve particular attention as their relationship to the two identified lineages is not clear-cut. While they appear to belong to M. spinolai based on cytogenetics and rDNA markers, COI results indicate a closer relationship to M. gajardoi. This disagreement can be due to mitochondrial DNA introgression or the retention of ancestral polymorphisms.

  16. Cytogenetics and genome evolution in the subfamily Triatominae (Hemiptera, Reduviidae).

    Science.gov (United States)

    Panzera, F; Pérez, R; Panzera, Y; Ferrandis, I; Ferreiro, M J; Calleros, L

    2010-01-01

    The subfamily Triatominae (Hemiptera, Reduviidae), vectors of Chagas disease, includes over 140 species. Karyotypic information is currently available for 80 of these species. This paper summarizes the chromosomal variability of the subfamily and how it may reveal aspects of genome evolution in this group. The Triatominae present a highly conserved chromosome number. All species, except 3, present 20 autosomes. The differences in chromosome number are mainly caused by variation in the number of sex chromosomes, due to the existence of 3 sex systems in males (XY, X(1)X(2)Y and X(1)X(2)X(3)Y). However, inter- and intraspecific differences in the position, quantity and meiotic behavior of constitutive heterochromatin, in the total genome size, and in the location of ribosomal 45S rRNA clusters, have revealed considerable cytogenetic variability within the subfamily. This cytogenetic diversity offers the opportunity to perform cytotaxonomic and phylogenetic studies, as well as structural, evolutionary, and functional analyses of the genome. The imminent availability of the complete genome of Rhodnius prolixus also opens new perspectives for understanding the evolution and genome expression of triatomines. The application of fluorescence in situ hybridization for the mapping of genes and sequences, as well as comparative analyses of genome homology by comparative genomic hybridization will be useful tools for understanding the genomic changes in relation to evolutionary processes such as speciation and adaptation to different environments.

  17. Research of Exocarpium Citri Grandis Fingerprint Based on Self-organization Competitive Neural Network%基于自组织竞争型神经网络的化橘红指纹图谱研究

    Institute of Scientific and Technical Information of China (English)

    陈南迪; 卢丽萍; 汪金玉; 林励

    2012-01-01

    Objective To establish the self-organization competitive neural network method for identifying the species by the fingerprints of different kinds of Exocarpium Citri Grandis(Cirtus grandis Peel). Methods The fingerprints of different species of Exocarpium Citri Grandis were established by fourier transform infrared speetroscopy and high performance liquid chromatogram (HPLC). And then we used the self-organization competitive neural network model to distinguish the different species of Exocarpium Citri Grandis. Results The self-organization competitive neural network for distinguish Exocarpium Citri Grandis of different species was established, and the rate of accuracy for infrared and HPLC fingerprint of the powder and the extract was more than 91.67 % in average. Conclusion The self-organizing competitiveneural network can be used for distinguishing different species of Exocarpium Citri Grandis by their fingerprints.%目的 建立不同品种化橘红指纹图谱的自组织竞争型人工神经网络判别方法.方法 采用傅里叶红外光谱法及HPLC法建立不同品种化橘红的指纹图谱,采用自组织竞争型人工神经网络进行模式识别.结果 自组织竞争型神经网络模型对化橘红粉末、提取物红外及HPLC指纹图谱预测平均准确率达91.67%以上.结论 自组织竞争型人工神经网络可有效用于化橘红品种的识别.

  18. The monofunctional catalase KatE of Xanthomonas axonopodis pv. citri is required for full virulence in citrus plants.

    Directory of Open Access Journals (Sweden)

    María Laura Tondo

    Full Text Available BACKGROUND: Xanthomonas axonopodis pv. citri (Xac is an obligate aerobic phytopathogen constantly exposed to hydrogen peroxide produced by normal aerobic respiration and by the plant defense response during plant-pathogen interactions. Four putative catalase genes have been identified in silico in the Xac genome, designated as katE, catB, srpA (monofunctional catalases and katG (bifunctional catalase. METHODOLOGY/PRINCIPAL FINDINGS: Xac catalase activity was analyzed using native gel electrophoresis and semi-quantitative RT-PCR. We demonstrated that the catalase activity pattern was regulated in different growth stages displaying the highest levels during the stationary phase. KatE was the most active catalase in this phase of growth. At this stage cells were more resistant to hydrogen peroxide as was determined by the analysis of CFU after the exposition to different H(2O(2 concentrations. In addition, Xac exhibited an adaptive response to hydrogen peroxide, displaying higher levels of catalase activity and H(2O(2 resistance after treatment with sub-lethal concentrations of the oxidant. In the plant-like medium XVM2 the expression of KatE was strongly induced and in this medium Xac was more resistant to H(2O(2. A XackatE mutant strain was constructed by insertional mutagenesis. We observed that catalase induction in stationary phase was lost meanwhile the adaptive response to peroxide was maintained in this mutant. Finally, the XackatE strain was assayed in planta during host plant interaction rendering a less aggressive phenotype with a minor canker formation. CONCLUSIONS: Our results confirmed that in contrast to other Xanthomonas species, Xac catalase-specific activity is induced during the stationary phase of growth in parallel with the bacterial resistance to peroxide challenge. Moreover, Xac catalases expression pattern is modified in response to any stimuli associated with the plant or the microenvironment it provides. The catalase Kat

  19. New records of stink bugs (Hemiptera: Pentatomidae) from Colombia.

    Science.gov (United States)

    Castro-Huertas, Valentina; Schwertner, Cristiano F; Fernández, Fernando

    2015-06-18

    New records of genera and species of stink bugs (Hemiptera: Pentatomidae) from Colombia are provided. Two genera are new records for South America: Alathetus and Schraderiellus. Fifteen genera are new record for Colombia: Agaclitus, Boea, Ceratozygum, Euthyrhynchus, Eritrachys, Doesburguedessa, Lopadusa, Marmessulus, Paralincus, Patanius, Peromatus, Phalaecus, Phoeacia, Rio, and Tyrannocoris. Forty-nine species from five subfamiles are recorded for the first time in Colombia. Asopinae: Coryzorhaphis carneolus Erichson, Coryzorhaphis superba Breddin, Euthyrhynchus floridanus (Linnaeus), Podisus sagitta Fabricius, Stiretrus anchorago (Fabricius), Stiretrus cinctellus Germar, Tylospilus peruvianus Horvath, Tyrannocoris nigriceps Thomas. Cyrtocorinae: Ceratozygum horridum (Germar). Discocephalinae: Agaclitus dromedarius Stål, Antiteuchus melanoleucus (Westwood), Antiteuchus sepulcralis (Fabricius), Dinocoris gibbosus (Fallou), Dinocoris variolosus (Linnaeus), Discocephalessa terminalis (Walker), Dryptocephala crenata Ruckes, Dryptocephala dentifrons (Latreille), Eurystethus ovalis Ruckes, Paralcippus dimidiatus (Ruckes), Alathetus rufitarsus Dallas, Eritrachys bituberculata Ruckes, Paralincus bimaculatus (Ruckes), Schraderiellus cinctus (Ruckes), Xynocoris recavus (Garbelotto & Campos). Edessinae: Brachystethus cribus (Fabricius), Brachystethus tricolor Bolívar, Doesburguedessa elongatispina Fernandes and Lopadusa fuscopunctata (Distant). Pentatominae: Banasa fulgida Thomas, Banasa paraexpallescens Thomas, Dichelops divisus (Walker), Dichelops nigrum Bergroth, Euschistus carbonerus Rolston, Mormidea bovilla (Distant), Mormidea triangularis (Walker), Murgantia bifasciata Herrich-Schaeffer, Murgantia violascens (Westwood), Oebalus pugnax (Fabricius), Oebalus ypsilon-griseus (DeGeer), Odmalea concolor (Walker), Patanius vittatus Rolston, Proxys albopunctulatus (Palisot), Proxys punctulatus (Palisot), Rhyncholepta grandicallosa Bergroth, Rio insularis Ruckes, Roferta

  20. Primer Registro para el Perú de Brachycaudus schwartzi (Bórner (Hemiptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Walter Díaz

    2013-04-01

    Full Text Available Se registra por primera vez para el Perú la especie Brachycaudus schwartzi (Bórner (Hemiptera: Aphididae, “pulgón pardo del duraznero”. La especie ha sido colectada en el departamento de Tacna. Material de referencia se encuentra depositado en la Colección Referencial de Insectos de la Unidad del Centro de Diagnóstico de Sanidad Vegetal del SENASA, Lima, Perú.

  1. Seasonal Effects on the Population, Morphology and Reproductive Behavior of Narnia femorata (Hemiptera: Coreidae)

    OpenAIRE

    Lauren A. Cirino; Christine W Miller

    2017-01-01

    Many insects are influenced by the phenology of their host plants. In North Central Florida, Narnia femorata (Hemiptera: Coreidae) spends its entire life cycle living and feeding on Opuntia mesacantha ssp. lata. This cactus begins producing flower buds in April that lead to unripe green fruit in June that ripen into red fruit through December. Many morphological and behavioral characteristics of N. femorata are known to be affected by cactus phenology in a controlled laboratory setting, inclu...

  2. Dopluise (Hemiptera: Coccoidea) geassosieer met die wipstertmier, Crematogaster peringueyi Emery (Hymenoptera: Formicidae)

    OpenAIRE

    Johannes H. Giliomee

    2015-01-01

    Neste van die wipstertmier, Crematogaster peringueyi (Hymenoptera: Formicidae), is op verskeie plekke langs die kus van die Wes-Kaap versamel. Die doel was om vas te stel watter dopluisagtiges (Hemiptera: Coccoidea) in die neste in assosiasie met hierdie miere leef. Dopluise van drie families, naamlik die Pseudococcidae (witluise), Coccidae (sagtedopluise) en Kerriidae (lakdopluise) is in die neste gevind, almal bekend daarvoor dat hulle heuningdou afskei. Hierdie mutualistiese verhoudi...

  3. Scale insect genus-group names and their families (Hemiptera: Sternorrhyncha: Coccoidea).

    Science.gov (United States)

    Williams, Douglas J; Denno, Barbara D

    2014-06-05

    Genus names of the scale insects (Hemiptera: Coccoidea) are listed with their current families. The list includes all generic names that are currently valid with synonyms, unjustified emendations, homonyms, nomia nuda and misspellings. The list has been compiled from many sources as discussed in the introduction. This is the first list to be prepared in recent years of all generic names and it is in alphabetical order.

  4. Novas Plantas Hospedeiras para o Percevejo Fitófago Leptoglossus zonatus (Dallas (Hemiptera: Coreidae

    Directory of Open Access Journals (Sweden)

    Evaldo Pires

    2012-12-01

    Abstract. Leptoglossus zonatus (Dallas (Hemiptera: Coreidae is a phytophagous bug that can be found in several crops due to availability of food and favorable conditions for the development. The aim of this research was to record the occurrence of L. zonatus colonizing plants of Malpighia emarginata Sessé & Moc (Malpighiaceae, Morus nigra Linnaeus (Moraceae, Mangifera indica Linnaeus (Anacardiaceae in Municipality of Sinop, Mato Grosso, Brazil. L. zonatus should be included in monitoring for the Integrated Pest Management (IPM in these plants.

  5. Integrated Pest Management of Aphis spiraecola (Hemiptera: Aphididae) in clementines: enhancing its biological control

    OpenAIRE

    GOMEZ MARCO, FRANCESC

    2016-01-01

    [EN] Aphis spiraecola Patch. (Hemiptera: Aphididae) is a key pest of clementines. Biological control of A. spiraecola is still poorly known and efforts were based on the use and conservation of parasitoids but it did not success. With all this said, the aims of this thesis were: i) to disentangle the reasons behind the low parasitism of A. spiraecola; ii) to determine when and how predators can control A. spiraecola populations; and, finally, iii) to evaluate whether a ground cover of Poaceae...

  6. Comparison of PCR,DIA and Pathogenicity Assay for Detection of Xanthomonas axonopodis pv.citri,the Causal Agent of Citrus Bacterial Canker Disease

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-kang; SUN Xian-yun; YIN You-ping; ZHOU Chang-yong; XIA Yu-xian

    2004-01-01

    Polymerase chain reaction (PCR) approach based on newly designed primers, JYF5/JYR5, was applied for specific detection of Xanthomonas axonopodis pv.citri(Xac). The efficiency and reliability of PCR method were compared with dot immunobinding assay (DIA) and classical pathogenicity test techniques for detecting suspensions of pure cells of Xac and soaking sap of citrus tissues. Detection sensitivity of PCR was about 4.5 cells or 1.56 pg target DNA per reaction which was higher than that of DIA (ca. 450 cells per dot).These three techniques (PCR assay, DIA and Pathogenecity test) could always detect Xac from symptomatic citrus samples. Different performances were obtained from citrus materials without symptoms, and the positive detection frequency was PCR, DIA and pathogenicity test.

  7. 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

    Directory of Open Access Journals (Sweden)

    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.

  8. Xanthomonas axonopodis pv. citri YaeQ structure reveals new compact protein fold built around a variation of the PD-(D/E)XK nuclease motif

    Energy Technology Data Exchange (ETDEWEB)

    Guzzo, Cristiane Rodrigues; Farah, Chuck Shaker [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica. Dept. de Bioquimica; Nagem, Ronaldo Alves Pinto [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Inst. de Ciencias Biologicas. Dept. de Bioquimica e Imunologia; Barbosa, Joao Alexandre Ribeiro Goncalves [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil). Centro de Biologia Molecular Estrutural

    2008-11-15

    The YaeQ family of proteins derives from close to two hundred species of Gram-negative bacteria. Despite their widespread distribution, their molecular and physiological functions are unknown. We used X-ray crystallography and multi-wavelength anomalous dispersion to determine the high resolution structure of the YaeQ protein (XAC2398) from the phytopathogen Xanthomonas axonopodis pv. citri. The novel structure revealed that YaeQ pertains to the PD-(D/E)XK superfamily of metal-dependent endonucleases. The phylogenetic distribution of YaeQ proteins and a detailed comparison of the YaeQ structure with that of other PD-(D/E)XK family members point to specific testable hypotheses regarding YaeQ function. (author)

  9. Influence of insecticide treatments on ant-hemiptera associations in tropical plantations.

    Science.gov (United States)

    Kenne, M; Djiéto-Lordon, C; Orivel, J; Mony, R; Fabre, A; Dejean, A

    2003-04-01

    In this survey conducted in southern Cameroon, we compared ant-Hemiptera associations on plantations treated with insecticides, on plantations 2 years after insecticide treatments ceased, and on control lots that never received insecticide treatments. By eliminating arboreal-nesting ants, insecticides favored the presence of "ecologically dominant" ground-nesting, arboreal-foraging species that occupied the tree crowns. The reinstallation of arboreal ants was slow as 2 yr after insecticide treatment ceased differences with the control lots were significant. This intermediary period also illustrated that arboreal ants can found and develop colonies on trees occupied by ground-nesting species. Certain arboreal species were more frequent during this intermediary period than on the control lots, showing that the period of installation in the trees was followed by competition between arboreal ants. We confirm that ground-nesting ants tend a wide range of hemipteran families, including well known agricultural pests, whereas arboreal ants, particularly dominant species, were mostly associated with Coccidae and Stictococcidae that do not pose problems to the supporting trees. A tree effect was also noted for both ant and hemipteran distribution. We concluded that because of insecticide use, ground-nesting ants pose problems through their associated Hemiptera. On the contrary, dominant arboreal ants, strong predators, benefit their supporting trees by excluding ground-nesting species and tending mostly nonpest Hemiptera. Nevertheless, certain of them, carpenter species or species likely to tend Pseudococcidae, have to be eliminated through integrated management.

  10. Identification and impact of natural enemies of Bactericera cockerelli (Hemiptera: Triozidae) in Southern California.

    Science.gov (United States)

    Butler, Casey D; Trumble, John T

    2012-10-01

    Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) is a major pest of potato, (Solanum tuberosum L.), tomato (Solanum lycopersicum L.), and peppers (Capsicum spp.). The purpose of our research was to identify and determine the impact of natural enemies on B. cockerelli population dynamics. Through 2 yr of field studies (2009-2010) at four different sites and laboratory feeding tests, we identified minute pirate bug, Orius tristicolor (White) (Hemiptera: Anthocoridae); western bigeyed bug, Geocoris pallens Stål (Hemiptera:Geocoridae), and convergent lady beetle, Hippodamia convergens Guérin-Méneville (Coleoptera: Coccinellidae) as key natural enemies of B. cockerelli in southern California potatoes, tomatoes, and bell peppers. In natural enemy exclusion cage experiments in the potato crop and in American nightshade, Solanum americanum Miller, the number of B. cockerelli surviving was significantly greater in the closed cage treatments, thus confirming the affect natural enemies can have on B. cockerelli. We discuss how this information can be used in an integrated pest management program for B. cockerelli.

  11. Nested-quantitative PCR approach with improved sensitivity for the detection of low titer levels of Candidatus Liberibacter asiaticus in the Asian citrus psyllid, Diaphorina citri Kuwayama.

    Science.gov (United States)

    Coy, M R; Hoffmann, M; Kingdom Gibbard, H N; Kuhns, E H; Pelz-Stelinski, K S; Stelinski, L L

    2014-07-01

    Candidatus Liberibacter asiaticus (CLas) is a phloem-limited bacterium transmitted by the Asian citrus psyllid, Diaphorina citri, and the presumptive causal agent of citrus greening disease. The current method of detection for CLas within plant and insect samples is by a presence/absence qPCR assay using the CLas 16S rDNA gene target. Although qPCR is highly sensitive, low bacterial titers or suboptimal qPCR conditions can result in false-negatives. Using a nested qPCR assay, we determined the false-negative rate of the 16S presence/absence qPCR assay was greater than 50%. Studies to determine the performance parameters of the qPCR assays for CLas 16S and Wingless (Wg), the D. citri endogenous gene, using plasmid and psyllid DNA, revealed suboptimal and variable performance of the 16S assay in psyllid samples. Average efficiencies and sensitivity limits of the plasmid assays were 99.0% and 2.7 copies of template for Wg, respectively, and 98.5% and 2.2-22.1 copies for 16S, respectively. Variability in efficiency was significantly greater in psyllid samples for both gene targets compared to the corresponding plasmid assays, and efficiencies as low as 76% were obtained for 16S. A secondary structure analysis revealed the formation of two stem-loop structures that block the forward and probe binding sites in the 16S template, which could hinder amplification. In summary, our results suggest that suboptimal qPCR efficiency is not uncommon for the 16S presence/absence qPCR assay, which combined with lowCLas titers in some samples, could contribute significantly to the under-reporting of CLas infection in psyllid and plant samples.

  12. All five host-range variants of Xanthomonas citri carry one pthA homolog with 17.5 repeats that determines pathogenicity on citrus, but none determine host-range variation.

    Science.gov (United States)

    Al-Saadi, Abdulwahid; Reddy, Joseph D; Duan, Yong P; Brunings, Asha M; Yuan, Qiaoping; Gabriel, Dean W

    2007-08-01

    Citrus canker disease is caused by five groups of Xanthomonas citri strains that are distinguished primarily by host range: three from Asia (A, A*, and A(w)) and two that form a phylogenetically distinct clade and originated in South America (B and C). Every X. citri strain carries multiple DNA fragments that hybridize with pthA, which is essential for the pathogenicity of wide-host-range X. citri group A strain 3213. DNA fragments that hybridized with pthA were cloned from a representative strain from all five groups. Each strain carried one and only one pthA homolog that functionally complemented a knockout mutation of pthA in 3213. Every complementing homolog was of identical size to pthA and carried 17.5 nearly identical, direct tandem repeats, including three new genes from narrow-host-range groups C (pthC), A(w) (pthAW), and A* (pthA*). Every noncomplementing paralog was of a different size; one of these was sequenced from group A* (pthA*-2) and was found to have an intact promoter and full-length reading frame but with 15.5 repeats. None of the complementing homologs nor any of the noncomplementing paralogs conferred avirulence to 3213 on grapefruit or suppressed avirulence of a group A* strain on grapefruit. A knockout mutation of pthC in a group C strain resulted in loss of pathogenicity on lime, but the strain was unaffected in ability to elicit an HR on grapefruit. This pthC- mutant was fully complemented by pthA, pthB, or pthC. Analysis of the predicted amino-acid sequences of all functional pthA homologs and nonfunctional paralogs indicated that the specific sequence of the 17th repeat may be essential for pathogenicity of X. citri on citrus.

  13. 橘全爪螨有螨叶率防治指标的初步研究%Preliminary Study on the Controlling Index of the Leaf Incidence of Panonychus citri

    Institute of Scientific and Technical Information of China (English)

    张志恒; 陈国庆; 陈亦根

    2000-01-01

    @@ 橘全爪螨(Panonychus citri Mcgregor)是为害柑橘的一种主要害虫,常因防治不及时而造成减产和品质下降.如何快速准确地实施虫情调查监测,适时指导药剂防治,是橘全爪螨综合治理的一个重要环节.

  14. Revision of the Neotropical treehopper genus Tolania (Hemiptera, Membracidae

    Directory of Open Access Journals (Sweden)

    Jesse L. Albertson

    2006-12-01

    Full Text Available The treehopper genus Tolania Stål (Hemiptera: Membracidae: Nicomiinae: Nicomiini and 69 valid species (59 new are described and illustrated based on adult morphology. Ten informal species groups are recognized based on a previously published phylogenetic analysis: (1 the dira species group comprising T. calista sp. nov., T. dira sp. nov., T. inca sp. nov., T. macaria sp. nov., T. secoya sp. nov., and T. zaparo sp. nov.; (2 the fasciata species group comprising T. fasciata (Walker, T. gracilis sp. nov., and T. laticlava sp. nov.; (3 the femoralis species group comprising T. femoralis Stål, T. fraterna Stål, and T. roberti sp. nov.; (4 the furcata species group comprising T. furcata sp. nov., T. tryphena sp. nov., and T. venezuelensis sp. nov.; (5 the hispida species group comprising T. alida sp. nov., T. hispida sp. nov., and T. periculosa sp. nov.; (6 the malefica species group comprising T. cactina sp. nov., T. curvata sp. nov., T. grallator sp. nov., T. jocosa sp. nov., T. mackameyi sp. nov., T. malefica sp. nov., T. obliqua (Walker, and T. terencia sp. nov.; (7 the obtusa species group comprising T. obtusa Fowler, T. obunca sp. nov., and T. torosa sp. nov.; (8 the opponens species group comprising T. alvira sp. nov., T. arcuata sp. nov., T. damia sp. nov., T. insolita sp. nov., T. lunata sp. nov., T. lurida sp. nov., T. opponens (Walker, T. oriana sp. nov., T. reflexa sp. nov., T. risa sp. nov., T. sinuata sp. nov., T. trilobata sp. nov., T. tumida sp. nov., T. umbella sp. nov., T. vitocensis sp. nov., T. woodi sp. nov., and T. xantha sp. nov.; (9 the peltacauda species group comprising T. brasiliensis sp. nov., T. iratafelis sp. nov., T. modesta sp. nov., T. peltacauda sp. nov., T. picta sp. nov., and T. thyrea sp. nov.; and (10 the semipellucida species group comprising T. atrata sp. nov., T. fimbriata sp. nov., T. nicia sp. nov., and T. semipellucida Stål. The following new species are not placed in species groups: T. anomala sp. nov

  15. Formic and acetic acids in degradation products of plant volatiles elicit olfactory and behavorial responses from an insect vector

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) vectors the bacterial pathogen presumed to be the etiological agent of citrus greening disease, Huanglongbing (HLB), a major threat to citrus industry worldwide. We studied antennal and behavioral responses of Diaphorina citri...

  16. Morphology of the female reproductive system and physiological age-grading of Megamelus scutellaris (Hemiptera: Delphacidae), a biological control agent of water hyacinth

    Science.gov (United States)

    The morphology of the female reproductive system in Megamelus scutellaris Berg (Hemiptera:Delphacidae), a biocontrol agent of Eichhornia crassipes (Mart.) Solms, was examined using standard light microscopy techniques. Ovaries extracted from individuals dissected in phosphate buffered saline were ex...

  17. Morphology of the first-instar nymph and adult female of Kermes echinatus Balachowsky, with a comparison to K. vermilio Planchon (Hemiptera, Coccoidea, Kermesidae

    Directory of Open Access Journals (Sweden)

    Malkie Spodek

    2012-11-01

    Full Text Available The first-instar nymph and the adult female of Kermes echinatus Balachowsky (Hemiptera, Coccoidea, Kermesidae are described and illustrated. This species is compared with K. vermilio Planchon, a morphologically similar species known in the Palaeractic region.

  18. Potential use of the fungus Beauveria bassiana against the western flower thrips Frankliniella occidentalis without reducing the effectiveness of its natural predator Orius sauteri (Hemiptera: Anthocoridae)

    Science.gov (United States)

    Orius sauteri (Poppius) (Hemiptera: Anthocoridae) is an important predator of western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). Orius sauteri would be directly exposed to the entomopathogenic fungus Beauveria bassiana (Bals.) Vuillemin in the field should the fu...

  19. 湖南柑橘大实蝇对不同柑橘品种的危害特点研究初报%The Damage Characteristics of Tetradacus citri Chen on Different Citrus Varieties in Hunan Province

    Institute of Scientific and Technical Information of China (English)

    林文力; 杨水芝; 潘美山; 陈海玲; 黄泽培; 龙建国; 肖伏莲

    2011-01-01

    采用定点观察和普查的方式对湖南省吉首市、麻阳县柑橘大实蝇的危害特点进行了研究.结果表明:柑橘大实蝇对不同柑橘品种的危害时间由早到晚依次为:脐橙>温洲蜜柑>冰糖橙≥大红甜橙=广柑>椪柑;其危害最严重的品种是脐橙,虫果率达63%,其次是早熟温洲蜜柑和冰糖橙,达22%,再次是椪柑,达6%;同时还发现,柑橘不同品种果皮表面存在产卵假痕迹现象.这些结果可为柑橘大实蝇的防治提供理论参考依据.%The damage characteristics of Tetradacus citri Chen in Mayang County, Jishou City, Hunan Province were investigated by fixed-point observation method and general survey method. The results indicated that the harm time of Tetradacus citri Chen on different varieties of citrus ordered as navel orange>satsuma mandarin>Citrus sinensis ^Citrus sineasis Osbeck cv. Dahong= Citrussinensis (L.) Osbeck >Citrus reticulata Blanco cv. Ponkan; the damage level of Tetradacus citri Chen on different varieties of citrus ordered as navel orange>early mature satsuma mandarin and Citrus sinensis >dtrus reticulata Blanco cv. Ponkan, and the insect infestation ratio of navel orange, early mature satsuma mandarin, Citrus sinensis and Citrus reticulata Blanco cv. Ponkan was 63%, 22%, 22% and 6%, respectively. Meanwhile, the research also showed that there are fake oviposition traces of Tetradacus citri Chen on the Peels of different varieties of citrus. These results above can provide the theory basis for the control of Tetradacus citri Chen.

  20. Biological parameters and thermal requirements of the parasitoid Praon volucre (Hymenoptera: Braconidae) with Macrosiphum euphorbiae (Hemiptera: Aphididae) as host

    NARCIS (Netherlands)

    Conti, De B.F.; Bueno, V.H.P.; Sampaio, M.V.; Lenteren, van J.C.

    2011-01-01

    The effect of temperature on the biology of Praon volucre (Haliday, 1833) (Hymenoptera: Braconidae) in Macrosiphum euphorbiae (Thomas, 1878) (Hemiptera: Aphididae) hosts was studied and the thermal requirements of the parasitoid were determined. Experiments were carried out at 16, 19, 22, 25, and 28

  1. New corological and biological data of the Red Gum Lerp Psyllid, Glycaspis brimblecombei Moore, 1964 in Italy (Hemiptera, Psyllidae

    Directory of Open Access Journals (Sweden)

    Ricardo Jiménez-Peydró

    2011-03-01

    Full Text Available Glycaspis brimblecombei Moore, 1964 is a psyllid (Hemiptera: Psyllidae pest of Eucalyptus, native toAustralia and first recorded in Europe: Spain in 2008 and more recently (2010 in Italy. The present paper dealswith recent research, carried out in central Italy, with new data on the distribution and biology of this species.

  2. Brochosome influence on parasitisation efficiency of Homalodisca coagulata (Say) (Hemiptera: Cicadellidae) egg masses by Gonatocerus ashmeadi Girault (Hymenoptera : Mymaridae)

    NARCIS (Netherlands)

    Velema, H.P.; Hemerik, L.; Hoddle, M.S.; Luck, R.F.

    2005-01-01

    1. Many cicadellid females in the tribe Proconiini (Hemiptera: Cicadellidae) cover their egg masses with specialised, usually rod-shaped, brochosomes as the eggs are being laid. The brochosomes are produced in Golgi complexes in the Malpighian tubules of Cicadellidae. In contrast to the gravid femal

  3. Review of the grassland leafhopper genus Nephotettix Matsumura (Hemiptera: Cicadellidae: Deltocephalinae: Chiasmini) from the Chinese mainland.

    Science.gov (United States)

    Duan, Yani; Zhang, Yalin

    2014-01-01

    The Chinese mainland species of the leafhopper genus Nephotettix Matsumura (Hemiptera: Cicadellidae: Deltocephalinae: Chiasmini) (Nephotettix cincticeps (Uhler), Nephotettix malayanus Ishihara & Kawase, Nephotettix nigropictus (Stål), Nephotettix parvus Ishihara & Kawase rec. n., and Nephotettix virescens (Distant)) are reviewed. This genus is redescribed. Variation is described and illustrated. Keys for their separation are provided together with a worldwide checklist.

  4. Evaluation of a method to quantify glassy-winged sharpshooter (Hemiptera: Cicadellidae) egg maturation during a feeding assay

    Science.gov (United States)

    Methods to improve an assay relating adult feeding to egg maturation by the glassy-winged sharpshooter (Hemiptera: Cicadellidae) were evaluated. The assay consisted of confining adult females to cowpea stems in parafilm enclosures and quantifying adult feeding and egg maturation. Adult feeding was...

  5. A laboratory study of sex- and stage-related mortality and morbidity in bed bugs (hemiptera: cimicidae) exposed to deltamethrin

    Science.gov (United States)

    Exposure of a pyrethroid-susceptible strain of bed bugs, Cimex lectularius L. (Hemiptera: Cimicidae) to varying concentrations of deltamethrin for 24h indicated there was no significant difference in mortality between males, females, and nymphs at 24h or 168h post-exposure. Most bed bugs classified ...

  6. Potential transmission of Pantoea spp. and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) to plants by Lygus hesperus (Hemiptera: Miridae)

    Science.gov (United States)

    Lygus hesperus Knight (Hemiptera: Miridae) is a key agricultural pest in the western United States. In a recent study, proteins from Pantoea ananatis and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) were identified in diet that was stylet-probed and fed upon by L. hesperus adults. P...

  7. A new species of Tamarixia Mercet (Hymenoptera, Eulophidae), parasitoid of Trioza aguacate Hollis & Martin (Hemiptera, Triozidae) in Mexico

    Science.gov (United States)

    Yefremova, Zoya; González-Santarosa, Graciela; Lomeli-Flores, J. Refugio; Bautista-Martínez, Néstor

    2014-01-01

    Abstract Tamarixia aguacatensis Yefremova, sp. n. (Hymenoptera: Eulophidae: Tetrastichinae) is described from Mexico as a parasitoid of the avocado psyllid, Trioza aguacate Hollis & Martin (Hemiptera: Triozidae). Trioza aguacate is a serious pest of avocado, Persea americana Miller. A key to the species of Tamarixia Mercet in Mexico is given. PMID:24478580

  8. A new species of Tamarixia Mercet (Hymenoptera, Eulophidae), parasitoid of Trioza aguacate Hollis & Martin (Hemiptera, Triozidae) in Mexico.

    Science.gov (United States)

    Yefremova, Zoya; González-Santarosa, Graciela; Lomeli-Flores, J Refugio; Bautista-Martínez, Néstor

    2014-01-01

    Tamarixia aguacatensis Yefremova, sp. n. (Hymenoptera: Eulophidae: Tetrastichinae) is described from Mexico as a parasitoid of the avocado psyllid, Trioza aguacate Hollis & Martin (Hemiptera: Triozidae). Trioza aguacate is a serious pest of avocado, Persea americana Miller. A key to the species of Tamarixia Mercet in Mexico is given.

  9. A new species of Tamarixia Mercet (Hymenoptera, Eulophidae, parasitoid of Trioza aguacate Hollis & Martin (Hemiptera, Triozidae in Mexico

    Directory of Open Access Journals (Sweden)

    Zoya Yefremova

    2014-01-01

    Full Text Available Tamarixia aguacatensis Yefremova, sp. n. (Hymenoptera: Eulophidae: Tetrastichinae is described from Mexico as a parasitoid of the avocado psyllid, Trioza aguacate Hollis & Martin (Hemiptera: Triozidae. Trioza aguacate is a serious pest of avocado, Persea americana Miller. A key to the species of Tamarixia Mercet in Mexico is given.

  10. Eriosomatine aphids (Hemiptera, Aphididae, Eriosomatinae) associated with moss and roots of conifer and willow in forests of the Pacific Northwest

    Science.gov (United States)

    Apterous adult morphs of eriosomatine aphids (Hemiptera, Aphididae, Eriosomatinae) associated with moss and/or roots of conifer or willow in forests of the Pacific Northwest including Alaska are described, illustrated, and keyed. In total, seven species (Clydesmithia canadensis Danielsson, Melaphis ...

  11. A new species in the genus Crisicoccus Ferris (Hemiptera: Coccomorpha: Pseudococcidae), with a key to Chinese species.

    Science.gov (United States)

    Zhang, Jiang-Tao; Wu, San-An

    2016-06-01

    A new mealybug, Crisicoccus ziziphus sp. nov. (Hemiptera: Coccomorpha: Pseudococcidae), collected on the leaves and twigs of Ziziphus jujuba (Rhamnaceae), is described from China. All the female developmental stages (adult, third-instar, second-instar and first-instar nymphs) are described and illustrated. Keys are provided to separate the female instars and to identify adult females of Crisicoccus species from China.

  12. Survey of 'Candidatus Liberibacter solanacearum' in carrot crops affected by the psyllid Trioza apicalis (Hemiptera: Triozidae) in Norway

    Science.gov (United States)

    The carrot psyllid Trioza apicalis Förster (Hemiptera: Triozidae) is a serious insect pest of carrot (Daucus carota L.) in northern Europe, where it can cause up to 100% crop loss. Although it was long believed that T. apicalis causes damage to carrot by injection of toxins into the plant, it was re...

  13. Occurrence and control of citrus melanose caused by Diaporthe citri%柑橘黑点病的发病规律和防治

    Institute of Scientific and Technical Information of China (English)

    姜丽英; 徐法三; 黄振东; 黄峰; 陈国庆; 李红叶

    2012-01-01

    近年来,柑橘黑点病(Diaporthe citri)在浙江、江西等柑橘产区普遍发生,逐渐成为柑橘最主要病害之一,严重影响鲜销果实的外观品质和销售价格.2008年以来,通过对该病的症状、发生规律和防治技术开展研究发现,果实整个生长期都能感病,但以果实膨大期最感病;黑点病的严重度与树龄、施肥水平和杀菌剂的使用次数关系密切;以座果后每隔20d使用保护性杀菌剂代森锰锌防治效果较好,代森锰锌中添加0.25%~0.50%矿物油(绿颖)能有效地提高其防效.文章同时结合国内外相关研究,对黑点病症状、病原、发生规律和防治技术作了较为详尽的综述.%Melanose, caused by Diaporthe citri, has become a serious disease on citrus fruits in citrus-growing region of Zhejiang, Jiangxi provinces etc. It deteriorates exterior quality and brings down sale price of citrus fruits for fresh marketing. We have been involved in the investigation of the symptoms, prevalence and control methods of this disease since 2008. It was demonstrated that citrus fruits are susceptible to this disease in whole developmental stage, and especially susceptible during the enlarging stage. The order of melanose severity was closely associated with citrus age, times of fertilization and fungicide application. The best control efficiency could be obtained by application of protective fungicides such as mancozeb (followed the instruction of manufactory) 20 days interval after fruit-setting. Superior efficiency would be even achieved when 0. 25% to 0. 5% mineral oil ( SK spray oil) was mixed with mancozeb. Inter- and intranational information regarding the symptoms, characteristics of pathogen, epidemic factors and disease control of melanose was elaborately integrated in this paper.

  14. 橘全爪螨种群空间分布与危害%Population Spacial Distribution and Harm of Panonychus citri

    Institute of Scientific and Technical Information of China (English)

    甘宗义; 朱红艳; 潭荣荣

    2012-01-01

    The spacial distribution pattern, population dynamics and harm of Panonychus citri McG on citrus tree were studied by test of theoretical distribution and analysis of spacial pattern indexes. The results showed that the population distribution of the mite suits with Negative-binomial distribution in citrus garden, and fits with Neyman distribution-A in lower population density too. The spacial distribution pattern presents loose colonies, in which distribution of the colonies is aggregated and the individuals in the colonies show random distribution. The aggregation intensity of population distribution is changing with changes in the mite population density. The aggregation in low density population is caused by environmental factors; and in highdeasity population it is concerned with their biological activities. When the population density a certain up to a certain harm grade, the spacial volume reaching and outstripping this harm level is not over 30% of the total space in citrus garden, accordingly, the area sprayed with insecticides for controlling the harmful mite should not be over 30% of all the area in the field.%通过理论分布的适合性检验、空间格局指标分析,对橘全爪螨(Panonychus citri McG)在温州蜜柑上的空间分布特征、动态与危害进行了系统研究.结果表明,橘全爪螨田间种群分布符合负二项分布,低密度下偶尔符合Neyman A分布.空间分布的基本成分为疏松的个体群,个体群内成员间的分布为随机分布,个体群间呈聚集分布,聚集强度随种群密度的变化而变化,种群低密度下的聚集主要由环境因素引起,高密度下的聚集与该螨自身生物学特性有关.当田间种群数量达到某一危害级别时,相应级别的危害空间容积不超过总体空间的30%,相应的田间药剂防治面积也不应超过总面积的30%.

  15. Occurrence of the Tamarix Leafhopper, Opsius stactogalus Fieber (Hemiptera: Cicadellidae), in Argentina.

    Science.gov (United States)

    Virla, Eduardo G; Logarzo, Guillermo A; Paradell, Susana L

    2010-01-01

    The paleartic tamarix leafhopper, Opsius stactogalus Fieber (Hemiptera: Cicadellidae), can reduce the growth of tamarisk due to the aggregate feeding imposed by their populations. The species was mentioned for Argentina in Metcalf's catalogue (1967) without locality or region reference, and the contributions on Cicadellidae published by many authors after Metcalf omitted this distributional data. Populations of O. stactogalus on Tamarix sp. were found in 12 sites between 28 degrees 48' to 39 degrees 17' S and 64 degrees 06' to 70 degrees 04' W, located in both the Neotropical and Andean biogeographic regions.

  16. Does cycad aulacaspis scale (Aulacaspis yasumatsui, Hemiptera: Diaspididae) play a direct role in causing soil phytotoxicity?

    Science.gov (United States)

    Watson, Gillian; Marler, Thomas E

    2014-01-01

    Cycad aulacaspis scale (CAS, Aulacaspis yasumatsui, Hemiptera: Diaspididae) was accidentally introduced to Guam in 2003, and has caused acute mortality of the dominant, endemic forest tree Cycas micronesica. A phytotoxic legacy in the soils beneath cycad trees killed by CAS over a period of about three years has been demonstrated. The origin of the toxicity may be large quantities of CAS-encrusted cycad leaf litter. We explore the possibility that a major contribution to this toxic legacy may come from the scale insects, not just from the plant material.

  17. Dopluise (Hemiptera: Coccoidea geassosieer met die wipstertmier, Crematogaster peringueyi Emery (Hymenoptera: Formicidae

    Directory of Open Access Journals (Sweden)

    Johannes H. Giliomee

    2015-02-01

    Full Text Available Neste van die wipstertmier, Crematogaster peringueyi (Hymenoptera: Formicidae, is op verskeie plekke langs die kus van die Wes-Kaap versamel. Die doel was om vas te stel watter dopluisagtiges (Hemiptera: Coccoidea in die neste in assosiasie met hierdie miere leef. Dopluise van drie families, naamlik die Pseudococcidae (witluise, Coccidae (sagtedopluise en Kerriidae (lakdopluise is in die neste gevind, almal bekend daarvoor dat hulle heuningdou afskei. Hierdie mutualistiese verhouding tussen die miere en dopluise, bekend as mirmekofilie, is fakultatief van aard. Die wipstertmier blyk ook nie spesifiek te wees wat betref die plant waarop hulle nes maak nie.

  18. A new species of Dysmicoccus damaging lavender in French Provence (Hemiptera, Sternorrhyncha, Pseudococcidae).

    Science.gov (United States)

    Germain, J-F; Matile-Ferrero, D; Kaydan, M B; Malausa, T; Williams, D J

    2015-07-01

    Une nouvelle espèce de Dysmicoccus nuisible à la lavande en Provence (France) (Hemiptera, Sternorrhyncha, Pseudococcidae). Dysmicoccus lavandulae Germain, Matile-Ferrero & Williams n. sp. est décrite et illustrée. Ses séquences ADN sont présentées. L'espèce vit sur Lavandula x intermedia cultivée pour la production d'essence de lavande en Provence. La liste des espèces de pseudococcines vivant sur les lavandes spontanées en France est dressée. Le statut des 2 genres voisins Trionymus Berg et Dysmicoccus Ferris est discuté.

  19. First report of Idiopterus nephrelepidis Davis, 1909 (Hemiptera: Aphididae from Bulgaria

    Directory of Open Access Journals (Sweden)

    Elena Tasheva-Terzieva

    2011-11-01

    Full Text Available Idiopterus nephrelepidis (Hemiptera: Aphididae is reported for the first time in Bulgaria on ornamental ferns in four greenhouses in Sofia and Varna. Dense colonies of apterous viviparous females and larvae were observed. The established host plants are Nephrolepis exaltata, Asplenium nidus and Pteris cretica. Infested ferns exhibit leaf deformation. The aphids were reared in laboratory conditions for four months. A morphometric study of apterae was carried out. Taking into account the presence of host plants of I. nephrelepidis in Bulgaria which are native to the local flora and the reports of the aphid from the Balkan area, it may spread in the country outdoors.

  20. Records of Natural Enemies of Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) Biotype B in Brazil.

    Science.gov (United States)

    Torres, L C; Lourenção, A L; Costa, V A; Souza, B; Costa, M B; Tanque, R L

    2014-04-01

    Collections of natural enemies of Bemisia tabaci biotype B (Genn.) (Hemiptera: Aleyrodidae) were made in Lavras, state of Minas Gerais, Brazil. In the greenhouse, 6,495 predators and 16,628 parasitoids belonging to three families were collected. In the field, 267 predators and 344 parasitoids belonging to five families were found. For the first time in Brazil, five species of predators associated with this whitefly were reported. Because of the diversity of natural enemies of B. tabaci biotype B recorded, this study points out the importance of these data for studies on integrated pest management.

  1. The genus Arctorthezia Cockerell (Hemiptera, Ortheziidae with the description of a new species

    Directory of Open Access Journals (Sweden)

    Éva Szita

    2015-01-01

    Full Text Available This paper describes a new species of Arctorthezia Cockerell (Hemiptera: Coccoidea: Ortheziidae from the Palaearctic region. The specimens were extracted from forest litter in the collections of Muséum d’histoire Naturelle de Genève, Switzerland, using Berlese funnels. Three further species, A. cataphracta (Olafsen, A. occidentalis (Douglas and A. pseudoccidentalis Morrison, are redescribed and re-illustrated. The genus Arctorthezia now contains five species. An identification key, diagnostic illustrations, photographs of unmounted females and new locality records of the Arctorthezia species currently known are provided.

  2. The Vine Mealybug Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) Damaging Vineyards in Brazil.

    Science.gov (United States)

    Pacheco da Silva, V C; Galzer, E C W; Malausa, T; Germain, J F; Kaydan, M B; Botton, M

    2016-08-01

    In the last decade, the incidence of mealybugs (Hemiptera: Pseudococcidae) in vineyards has increased, especially on crops grown under plastic covering, in the Serra Gaúcha region of southern Brazil where the major Brazilian wineries are concentrated. Eggs, nymphs, and female adults were collected in two highly infested vineyards in Bento Gonçalves City, Rio Grande do Sul, Brazil. Mealybugs were identified by morphological and molecular techniques as the vine mealybug Planococcus ficus (Signoret). This is a principal mealybug pest of vineyards worldwide, and this is the first record of damage from this species in Brazil.

  3. [First record of Platycorypha nigrivirga Burckhardt (Hemiptera: Psylloidea), in Tipuana tipu (Benth.), from Brazil].

    Science.gov (United States)

    Santana, Dalva L Q; Burckhardt, Daniel; Aguiar, António M F

    2006-01-01

    The occurrence of Platycorypha nigrivirga Burckhardt (Hemiptera: Psyllidae, Acizzinae), is reported for the first time, in Brazil. The psyllid was observed causing injuries on leaves and shoots of Tipuana tipu (Benth.), in urban areas of Paraná State. P. nigrivirga are tiny sap-sucking insects that feed on phloem and cause curling, stains and fall of leaves. The excrements of these insects accumulate on the leaves propitiating fungus growth on the leaves, or they fall in great amount on the cars dirtying them as if they were sparkling of white and sticky ink.

  4. Cicadidae types (Hemiptera-Cicadomorpha) housed at the Museo de La Plata entomological collection (Argentina).

    Science.gov (United States)

    De Remes Lenicov, Ana M Marino; Maciá, Arnaldo; Pianzola, Bruno

    2015-06-23

    A catalog of the 161 type specimens of species of Hemiptera Cicadidae housed in the collection of the Entomology Division of the Museo de La Plata is presented. This collection represents 52 species grouped in 19 genera. For each species the original and current names, bibliographic references, type category, number of specimens, gender, Museo de La Plata code numbers, and transcription of data from labels (country, province, locality, date of collection, collector's name, and hosts) are given. Information about the state of preservation of the specimens in each series and photographs of each type species are also provided.

  5. The structure of integument and wax glands of Phenacoccus fraxinus (Hemiptera: Coccoidea: Pseudococcidae)%The structure of integument and wax glands of Phenacoccus fraxinus (Hemiptera:Coccoidea:Pseudococcidae)

    Institute of Scientific and Technical Information of China (English)

    Yanfeng ZHANG; Yingping XIE; Jiaoliang XUE; Xiaohong FU; Weimin LIU

    2012-01-01

    Using scanning electron microscopy and optical microscopy,we studied the structure of the integument and wax glands of the mealybug,Phenacoccus fraxinus Tang (Hemiptera:Coccoidea:Pseudococcidae).We observed the ultrastructure of four wax pores including trilocular,quinquelocular,and multilocular pores as well as tubular ducts,recording characteristics of their structure,size and distribution.We found that that the integument of the mealybug consists of three main layers—the procuticle,epidermis and basement membrane—and four sub-layers of the procuticle—the epicuticle,exocuticle,endocuticle and formation zone.The waxsecreting gland cells were closely arranged in epidermis.All of them were complex and composed of one central cell and two or more lateral cells.These complex cells possess a large common reservoir for collection and storage.Synthesized by the glandular cells,the wax is excreted outside integument through canals.

  6. Fungal flora of the digestive tract of Triatoma infestans (Hemiptera: Reduviidae from Argentina Flora fúngica de tractos digestivos en Triatoma infestans (Hemiptera: Reduviidae en Argentina

    Directory of Open Access Journals (Sweden)

    G. A. Marti

    Full Text Available A survey of the fungal microbiota of the digestive tract of Triatoma infestans (Klug (Hemiptera: Reduviidae adults was carried out. Insects captured in the field from different provinces in Argentina, as well as individuals reared in artificial colonies, were used for dissection. Axenic cultures of the fungal species were identified and were deposited with mycological collections at La Plata , Argentina. A total of 33 fungal species, with the exception of three that were mycelia sterilia, belonging to 11 genera were identified. Thirty two species belonged to Ascomycota (Eurotiomycetes and Sordariomycetes and one to Zygomycota (Zygomycetes. The genera with the greatest number of species were Penicillium (15, Aspergillus (5, and Cladosporium (2. Among the isolated fungi, some of the species were entomopathogenic or pathogens of humans and other animals.En el presente estudio se realizó un relevamiento de la flora fúngica microbiana en tractos digestivos de adultos de Triatoma infestans (Klug (Hemiptera: Reduviidae. Se disecaron insectos capturados del campo en diferentes provincias Argentinas, así como también se utilizaron individuos de una colonia artificial. Fueron realizados cultivos axénicos de las especies fúngicas aisladas, los que fueron identificados y luego depositados en las colecciones de hongos entomopatógenos del CEPAVE La Plata , Argentina. Fueron identificadas 33 especies fúngicas perteneciente a 11 géneros. Treinta y dos especies pertenecen a Ascomycota (Eurotiomycetes y Sordariomycetes y una a Zygomycota (Zygomycetes. Los géneros con mayor número de especies fueron Penicillium (15, Aspergillus (5, y Cladosporium (2. Entre los aislamientos fúngicos, algunas de las especies encontradas son entomopatogénicas o patógenas de humanos y otros animales.

  7. Primeiro registro da cochonilha Pendularia paraguariensis Granara de Willink, 1999 (Hemiptera: Coccidae no Brasil First record of Pendularia paraguariensis Granara de Willink, 1999 (Hemiptera: Coccidae in Brazil

    Directory of Open Access Journals (Sweden)

    Adriano Luiz Kussler

    2004-08-01

    Full Text Available Pendularia paraguariensis Granara de WillinK, 1999 (Hemiptera: Coccidae foi registrada atacando plantas de erva-mate, pela primeira vez no Brasil, no município de Chapecó (27°05’47"S, 52°37’06"W,SC de setembro de 2002 a janeiro de 2003, mas outros 32 ervais não apresentaram a ocorrência desse inseto. Esta cochonilha pode causar danos como a degeneração dos ramos primários devido a constante sucção de seiva. O contorno do corpo é oval arredondado (2,68mm x 2,60mm com antenas curtas e robustas com sete segmentos. Esta espécie é caracterizada pela presença e distribuição de poros preoperculares e setas hipopigiais.The presence of Pendularia paraguariensis Granara de WillinK, 1999 (Hemiptera: Coccidae was reported for the first time in Brazil in the town of Chapecó, Santa Catarina State (27°05’47"S, 52°37’06"W, attacking Paraguay tea plants (Ilex paraguariensis, from September 2002 to January 2003. Other 32 Paraguay tea plantations were inspected and there was not occurrence of this insect. This cochineal can cause degeneration of the branches where they are due to the constant suction of the sap. The contour of the body is rounded oval (2.68mm x 2.60mm and it has short and robust antennas with seven segments. This species is characterized by the presence and distribution of preoperculary pores and hypopygial arrows.

  8. Detection of citrus huanglongbing-associated 'Candidatus Liberibacter asiaticus' in citrus and Diaphorina citri in Pakistan, seasonal variability, and implications for disease management.

    Science.gov (United States)

    Razi, Muhammad F; Keremane, Manjunath L; Ramadugu, Chandrika; Roose, Mikeal; Khan, Iqrar A; Lee, Richard F

    2014-03-01

    We report the detection of the huanglongbing (HLB)-associated bacterium 'Candidatus Liberibacter asiaticus' from both plants and insects in Pakistan and the seasonal variability in the numbers of 'Ca. L. asiaticus'-positive psyllid vector, Diaphorina citri. Our studies showed that 'Ca. L. asiaticus' was detectable from trees in areas with maximum temperatures reaching nearly 50°C (average maximum of 42°C). However, the bacterium was present at very low levels in psyllids both in summer (June to August) and autumn (September to November) in contrast to reports from Florida, where the bacterium was detectable at very high levels during October to November. We hypothesize that hot summer temperatures in Pakistan may interfere with acquisition and replication of 'Ca. L. asiaticus' in psyllids and may lead to dead or non transmissible 'Ca. L. asiaticus' in plants. Psyllid counts were very low in both summer and winter, showed a population peak ('Ca. L. asiaticus'-positive vectors) in spring, and showed a larger peak ('Ca. L. asiaticus'-free psyllids) in autumn. Natural thermotherapy during hot summers and a low vector population during environmental extremes may have played a major role in long-term survival of the citrus industry in Pakistan. These results may be useful in developing management strategies for U.S. citrus industries in Texas and California.

  9. The filamentous phage XacF1 causes loss of virulence in Xanthomonas axonopodis pv. citri, the causative agent of citrus canker disease

    Directory of Open Access Journals (Sweden)

    Abdelmonim Ali Ahmad

    2014-07-01

    Full Text Available In this study, filamentous phage XacF1, which can infect Xanthomonas axonopodis pv. citri (Xac strains, was isolated and characterized. Electron microscopy showed that XacF1 is a member of the family Inoviridae and is about 1000 nm long and 16 nm in width. The genome of XacF1 is 7325 nucleotides in size, containing 13 predicted open reading frames (ORFs, some of which showed significant homology to Ff-like phage proteins such as ORF1 (pII, ORF2 (pV, ORF6 (pIII, and ORF8 (pVI. XacF1 showed a relatively wide host range, infecting seven out of 11 strains tested in this study. Frequently, XacF1 was found to be integrated into the genome of Xac strains. This integration occurred at the host dif site (attB and was mediated by the host XerC/D recombination system. The attP sequence was identical to that of Xanthomonas phage Cf1c. Interestingly, infection by XacF1 phage caused several physiological changes to the bacterial host cells, including lower levels of extracellular polysaccharide production, reduced motility, slower growth rate, and a dramatic reduction in virulence. In particular, the reduction in virulence suggested possible utilization of XacF1 as a biological control agent against citrus canker disease.

  10. The weathervane model, a functional and structural organization of the two-component alkanesulfonate oxidoreductase SsuD from Xanthomonas citri

    Energy Technology Data Exchange (ETDEWEB)

    Pegos, V.R. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Oliveira, P.S.L.; Balan, A. [Laboratorio Nacional de Biociencias - LNBIO, Campinas, SP (Brazil)

    2012-07-01

    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{sub 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{sub 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{sub 2}, FMN or both substrates, we characterized the residues of the pocket, the mechanism of substrate interaction and transfer of electrons from NADPH{sub 2} to FMN. This is the first report that links functional and biochemical data with structural analyses. (author)

  11. Repellent Activity of Extracts of Wild Rice Species against Panonychus citri and Aphis citricola in Associated with Esterase Isoenzyme in Insests

    Institute of Scientific and Technical Information of China (English)

    WAN Shu-qing; LIU Xiang-fa; FENG Guo-zhong; PAN Da-jian

    2006-01-01

    Six species of wild rice with different ecophenotypes including Oryza grandiglumis (E6-1, E6-3 / 6-4), O. minuta (E13-9,E13-13), O. officinalis (E15-8, E15-13), O. punctata (E16-1, E16-3, E1 6-13), O. granulata (E7-4), and O. latifolia (101392, E9-1, E9-10)were extracted with methnol and the repellent activity of the extracts against the two insects Aphis citricola and Panonychus citri were studied. The extracts of O. officinalis E15-8 showed higher repellent rate to the two insects than those of the other species. The repellent rates of the extracts of E15-8 to P. citriand A. citricola were 83.26% and 87.86% at 5×104 μg/mL in 24 h and 87.95% and 82.43% in 48 h, respectively. The extracts of O. officinalis E15-8 had the effect of inhibition to the esterase of the two insects.

  12. Evaluation of suitable reference genes for quantitative RT-PCR during development and abiotic stress in Panonychus citri (McGregor) (Acari: Tetranychidae).

    Science.gov (United States)

    Niu, Jin-Zhi; Dou, Wei; Ding, Tian-Bo; Yang, Li-Hong; Shen, Guang-Mao; Wang, Jin-Jun

    2012-05-01

    Quantitative real time reverse transcriptase polymerase chain reaction (RT-qPCR) is preferred for gene expression analysis in living organisms. Currently, it is a valuable tool for biological and ecological studies as it provides a relatively straightforward way to assess the relevance of transcriptional regulation under developmental and stress tolerance conditions. However, studies have shown that some commonly used reference genes varied among different experimental treatments, thus, systematic evaluation of reference genes is critical for gene expression profiling, which is often neglected in gene expression studies of arthropods. The aim of this study is to identify the suitable reference genes for RT-qPCR experiments involving various developmental stages and/or under abiotic stresses in citrus red mite Panonychus citri, a key pest in citrus orchards worldwide. GeNorm, NormFinder, and Bestkeeper software analysis indicates that elongation factor-1 alpha (ELF1A), RNA polymerase II largest subunit, alpha tublin, and glyceraldhyde-3-phosphate dehydrogenase (GAPDH) are the most stable reference genes in various developmental stages, meanwhile, ELF1A and GAPDH were the most stable reference genes under various abiotic stresses. Furthermore, this study will serve as a resource to screen reference genes for gene expression studies in any other spider mite species.

  13. Population Dynamics of Empoasca fabae (Hemiptera: Cicadellidae) in Central Iowa Alfalfa Fields.

    Science.gov (United States)

    Weiser Erlandson, L A; Obrycki, J J

    2015-01-01

    Adults and nymphs of Empoasca fabae Harris (Hemiptera: Cicadellidae) and adults of predatory species in the families Coccinellidae, Anthocoridae, Nabidae, Chrysopidae, and Hemerobiidae were sampled in Iowa alfalfa fields from June to September in 1999 and 2000. The relationship between each predatory taxa and E. fabae was examined using regression analysis. In 2000, all predators were found to be positively correlated with the presence of E. fabae during all periods sampled and most likely contributed to mortality. Orius insidiosus (Say) (Hemiptera: Anthoridae) was the most numerous insect predatory species; population numbers ranged from 0 to 1 and 0.1 to 3.7 adults per 0.25 m(2) in 1999 and 2000, respectively. Partial life tables were constructed for E. fabae nymphs for two alfalfa-growing periods. Nymphs were grouped into three age intervals: first and second, third and fourth, and fifth instars. For the first alfalfa growing period examined, E. fabae nymphal mortality was 70% in 1999 and 49% in 2000. During the last growing period of each season (August-September), total nymphal mortality was relatively low (<25%). Adult E. fabae density ranged from 5.4 to 25.6 and 1.4-9.2 per 0.25 m(2) in 1999 and 2000, respectively. E. fabae population peaks were similar for each age interval in all growing periods. This study provides further information on the population dynamics of E. fabae and its relationship with select predatory species in Iowa alfalfa fields.

  14. Bionomics of Asian citrus psyllid (Hemiptera: Liviidae) associated with orange jasmine hedges in southest central Florida, with special reference to biological control by Tamarixia radiata

    Science.gov (United States)

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is an important pest in Florida because it vectors bacteria responsible for citrus huanglongbing disease. In addition to infesting citrus, orange jasmine (Murraya paniculata) is one of ACP’s favorite host plants and is widely grown as an orn...

  15. Optimization of Extraction Technology for Inositol from Exocarpium Citri Grandis%正交试验法优选化橘红中肌醇提取工艺

    Institute of Scientific and Technical Information of China (English)

    陈地灵; 陈振兴; 林励; 吴泽青; 吴俊生

    2012-01-01

    [目的]优选化橘红中肌醇最佳提取工艺.[方法]以乙醇浓度、料液比和提取温度为考察因素,采用高效液相一蒸发光散射检测器(HPLC-ELSD)色谱法测定化橘红中肌醇含量,采用正交试验法优选化橘红中肌醇最优提取工艺.[结果]化橘红中肌醇最佳提取工艺为体积分数70%乙醇、料液比1∶20、提取温度100℃、每次时间45 min、提取2次.[结论]本研究优选得到的提取工艺稳定、提取率高,可用于化橘红中肌醇的提取.%Objective To optimize the extraction technology for the inositol from Exocarpium Citri Grandis. Methods With ethanol concentration, the ratio of material to solvent and extracting temperature as factors, the extraction technology for the inositol from Exocarpium Citri Crandis was optimized by orthogonal design and through the determination of inositol content by high performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD). Results The optimal extraction technology was as follows; 70% ethanol, the ratio of material to solvent being 1:20, extraction at 100℃, for 45 min and extraction twice. Conclusion The extraction technology is steady, extraction percentage is higher and the technology is suitable for the extraction of inositol from Exocarpium Citri Crandis.

  16. Advances in Biological Control of Citrus Psyllid Diaphorina citri, a Vector Insect of Citrus Huanglongbing Disease%黄龙病媒介昆虫柑橘木虱生物防治新进展

    Institute of Scientific and Technical Information of China (English)

    代晓彦; 任素丽; 周雅婷; 任顺祥; 邱宝利

    2014-01-01

    The citrus psyllid, Diaphorina citri Kuwayama, is the primary vector of citrus Huanglongbing disease, Candidatus Liberibacter asiaticus, which has the huge potential threats to the development of citrus industry in China. Based on the comprehensive understanding of D. citri control technologies, we reviewed the latest advances in biological control of D. citri and forecasted its future prospects. The main biological control resources of citrus psyllid currently are natural enemy insects and entomopathogenic fungi, among which predatory ladybeetles, lacewings, spiders and hover flies are the dominant species of predator, while Tamarixia radiata and Diaphorencyrtus aligarhensis are the two dominant parasitoids in China. Several representative entomopathogenic fungi include Lecanicillium lecanii, Isaria fumosorosea, Beauveria bassiana and Hirsutella citriformis have been reported with high virulence to citrus psyllid. This current review is expected to provide technical support and theoretical reference for efficient and sustainable control of citrus psyllid in the future.%柑橘木虱Diaphorina citri Kuwayama是柑橘黄龙病的重要媒介昆虫,对我国柑橘产业的健康发展潜在着巨大的威胁。本文在综合国内柑橘木虱防控技术的基础上,对近年来柑橘木虱生物防治的最新研究进展进行了综述,并且对其生物防治的发展前景给予了展望。目前应用于柑橘木虱生物防治的天敌资源主要是天敌昆虫及昆虫病原真菌,其中捕食性天敌主要包括瓢虫、食蚜蝇、草蛉和蜘蛛,寄生性天敌昆虫主要包括啮小蜂和跳小峰;昆虫病原真菌主要包括蜡蚧轮枝菌、拟青霉、白僵菌、桔形被毛孢等。期望通过对柑橘木虱生物防治工作的综述,为我国今后柑橘木虱的科学、高效防控及其可持续治理提供参考,不断推动我国柑橘产业的健康发展。

  17. Efeito do meio de cultura, temperatura, fotoperíodo e fungicidas no crescimento micelial e no controle de Alternaria alternata f. sp. citri, causador da mancha marrom do tangor murcote

    OpenAIRE

    Colturato,Adimara Bentivoglio

    2006-01-01

    A mancha marrom de alternaria, causada pela Alternaria alternata f. sp. citri, afeta o tangor murcote causando lesões em folhas, ramos e frutos, acarretando em desfolha e manchas que depreciam o fruto comercialmente. Os objetivos deste trabalho foram verificar o efeito do meio de cultura no isolamento, da temperatura e do fotoperíodo no crescimento micelial do patógeno, avaliar a sensibilidade do patógeno à fungicidas in vitro e estabelecer o melhor produto e dose para o controle da doença no...

  18. 基于电子舌技术对不同年份的化橘红的识别%Discrimination of Exocarpium Citri Grandis in Different Years Based on Electronic Tongue Techniques

    Institute of Scientific and Technical Information of China (English)

    熊萧萧; 王鲁峰; 徐晓云; 潘思轶; 王可兴

    2012-01-01

    不同年份的化橘红功效和价格均存在差异,为了快速识别未知橘红样品的年份,采用电子舌对2001~2010年的10个样品和一个盲样进行了分析.对原始数据采用主成分分析和判别因子分析.结果表明:主成分分析可以将不同年份的样品进行有效的区分,判别因子分析可以更好地区分不同年份的样品,并能进行盲样识别.在模式识别中,判别因子分析法的识别结果均优于主成分分析法,前者2个判别因子的累计方差贡献量达到了99.929%.电子舌可以较好地区分不同年份的化橘红,改进后有望应用于化橘红的快速检测.%The effect and price vary in Exocarpium Citri Grandis of different years. Ten samples of Exocarpium Citri Grandis produced from 2001 to 2010 were analyzed with electronic tongue to discriminate their ages. The study shows that both Principal Component Analysis (PCA) and Discriminant Factor Analysis (DFA) can be used to discriminate samples of different years with the latter mathod being more accurate. In the pattern recognition, the result of DFA is also more accurate than PCA with the fact that its conmulative contribution of 2-dimentional principal component reached as high as 99.929%. In conclusion, electronic tongue can be utilized as an effective way to discriminate the age level of Exocarpium Citri Grandis. The results of this study suggest the possibility of application of the propsed method in the rapid detection and analysis of Exocarpium Citri Grandis in the process of production, sales, and other related fields.

  19. Studies on Growth and Decline Law and Chemical Control of Panonychus citri in Lemon Orchard in Ruili%瑞丽柠檬园红蜘蛛消长规律及药剂防治研究

    Institute of Scientific and Technical Information of China (English)

    王自然; 段惠芬; 彭满秀; 郭俊; 赵俊; 潘黎; 高俊燕

    2014-01-01

    The growth and decline law and chemical control of Panonychus citri in lemon orchard are studied in Ruili city , Yunnan province .The results indicate that Panonychus citri occurs mainly from November to the next January , and its population density reaches a peak (2500~3000 heads per plant) in middle January;the occurrence quantity of this mite is more in the north and south of lemon crown;the occurrence and damage of Panonychus citri in lemon orchard are closely related with temperature , hu-midity, food, fertilization, chemical control and so on;among the tested 7 kinds of pesticides, 4%Spirodiclofen SC, 1.8%Abam-ectin EC and 73%Propargite EC have better control effects on Panonychus citri, and they are safe and harmless to the young shoots , flowers and young fruits of lemon .%在云南省瑞丽市进行了柠檬园红蜘蛛的消长规律及药剂防治研究。结果表明:柠檬红蜘蛛主要在11月至次年1月发生,其发生量在1月中旬达到高峰(2500~3000头/株);红蜘蛛在树冠北方、南方的发生量较多;柠檬园红蜘蛛的发生和为害与温度、湿度、食料、施肥、施药等因素关系密切;在7种供试药剂中,以4%螺螨酯悬浮剂、1.8%阿维菌素乳油和73%炔螨特乳油对红蜘蛛的防治效果较好,且对柠檬的嫩梢、花和幼果安全无害。

  20. Occurrence of Aleurocanthus woglumi Ashby, 1915 (Hemiptera: Aleyrodidae at Rio de Janeiro State = Ocorrência de Aleurocanthus woglumi Ashby, 1915 (Hemiptera: Aleyrodidae no Estado do Rio de Janeiro.

    Directory of Open Access Journals (Sweden)

    Márcio Coutinho de Almeida

    2014-12-01

    Full Text Available Citrus Blackfly’s, Aleurocanthus woglumi (Hemiptera: Aleyrodidae, is considered by the National Plant Protection Organization/Brazilian Ministry of Agriculture (NPPO/MAPA as a present quarantine pest (List A2, which occurs in 20 Brazilian States. The aim of this study is to report its occurrence in the Rio de Janeiro State, since its first notification in 2010. = A Mosca-Negra-dos-Citros, Aleurocanthus woglumi (Hemiptera: Aleyrodidae, é considerada pela Organização Nacional de Proteção Fitossanitária/Ministério da Agricultura (ONPF/MAPA, como praga quarentenária presente (Lista A2, com registros oficiais de ocorrência em 20 Estados brasileiros. O objetivo deste trabalho foi registrar sua ocorrência no Rio de Janeiro desde a sua primeira notificação, no ano de 2010.

  1. First record of occurrence of mosca-negra-dos-citrus, Aleurocanthus woglumi Ashby, 1915 (Hemiptera: Sternorrhyncha: Aleyrodidae) in Roraima, Brazil = Primeiro registro da ocorrência de mosca-negra-dos-citros, Aleurocanthus woglumi Ashby, 1915 (Hemiptera: Aleyrodidae) em Roraima

    OpenAIRE

    Francisco Clemilto da Silva Maciel; Marcos Wanderley da Silva; Anderson Gonçalves da Silva; Ruy Guilherme Correia; Paulo Roberto Silva Farias; Antonio Cesar Silva Lima

    2011-01-01

    The Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) is an important pest of citrus. Originated in Asia, this pest was detected in Brazil for the first time in the State of Para, Brazil in 2001. In the culture of citrus fruits the black fly carries direct and indirect damage, impeding the development and production of plants. In addition to restricting trade in local areas from its occurrence to the presence of the plague, since the A. woglumi quarantine pest is considered present (A2) of...

  2. Bioactivity of the latex from Parahancornia amapa (Apocynaceae on the development of Rhodnius nasutus (Hemiptera, Reduviidae, Triatominae under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Marcio B. P. Lopes

    2014-12-01

    Full Text Available Bioactivity of the latex from Parahancornia amapa (Apocynaceae on the development of Rhodnius nasutus (Hemiptera, Reduviidae, Triatominae under laboratory conditions. The aim of this study was to verify the effects of the methanolic fraction of the latex from Parahancornia amapa (Apocynaceae (PALAM on individuals of the species Rhodnius nasutus Stål (Hemiptera, Triatominae. Many of the insects treated with the substance presented deformities and these may interfere in the feeding and possibly hinder the reproductive capacity. They also presented significant mortality during the molt when compared to the control group, noting a gradual increase in mortality. The treated insects also presented delayed nymphal development (5th instar and higher adult longevity.

  3. 柑橘木虱对柑橘不同品种的趋性%Diaphorina citri's Gost Preference on Thirteen Citrus Varieties

    Institute of Scientific and Technical Information of China (English)

    陈建利; 阮传清; 刘波; 范国成; 段永平; D.HALL

    2011-01-01

    用2种方法测定了柑橘木虱Diaphorina citri Kuw.成虫对13个柑橘品种离体嫩梢的选择性.结果表明,对不同品种进行两两组合的选择性试验,柑橘木虱停靠在处理组合早金和四季斑叶橘的虫量占总虫量的23%和1%,停靠在处理组合台湾玫瑰橙和纽荷尔脐橙上的虫量分别占总虫量的33%和20%,停靠在处理组合日辉和佩奇甜橙上虫量分别占总虫量的38%和15%,两两之间差异显著.将13个品种组合在一起进行选择性试验,结果表明柑橘木虱停靠在纽荷尔、福橘和佩奇甜橙上的成虫数量为每梢3.2~6.6只·d-1,显著高于木虱在其余10个品种枝梢上的停靠数量.福橘是柑橘黄龙病高发品种的原因是其对柑橘木虱的吸引力较强.%Under laboratory conditions, preference of adult Asian Citrus Psyllid (ACP), Diaphorina citri Kuw, for infestation among 13 citrus varieties was determined with two experimentations. Experiment A applied every 2 detached shoots of different citrus varieties and put together for choice. Experiment B used the detached shoots of all tested citrus varieties and put together for choice. The results of Experiment A revealed that the percentage of ACP adults on each shoot of Citrus sinensis (L.) Osbeck cv. Earlygold and C. medurensis (C. mitis) cv. Varigated Calamondin were 23 % and 1 %, respectively, which was significantly different from each other. The percentage on C. sinensis Osbeck cv. Taiwanmeiguicheng (33%) and cv. Newhall Navel Orange (20%) were also significantly different from each other. Significant different percentages of ACP adults were also observed between C. reticulata C. paradisi cv. Rihui (38%) and C. reticulata C. grandis cv. Page (15%). In Experiment B, the number of ACP on the shoots of C. sinensis Osbeck cv. Newhall Navel Orange, C. tangerina Tanaka cv. Fuju and C. reticulata Citrusgrandis cv. Page was 3.2-6.6 adults · shoot-day-1 , which were significantly higher than that

  4. 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.

  5. 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.

  6. Effect of temperature on life history and population growth parameters of Planococcus citri (Homoptera, Pseudococcidae on coleus [Solenostemon scutellarioides (L. Codd.

    Directory of Open Access Journals (Sweden)

    Goldasteh Shila

    2009-01-01

    Full Text Available The development, life history, reproduction, and population growth parameters of Planococcus citri Risso on coleus [Solenostemon scutellarioides (L. Codd.] were studied at various temperatures ranging from 10 to 37ºC, 70±10% RH, and photoperiod length of 16: 8 h (L: D. Females and males successfully developed into adults at from 15 to 32ºC and 18 to 32ºC, respectively. All first instars died at 10, 12, and 37ºC. Lower temperatures (10, 12, and 15ºC caused higher egg mortality than did higher temperatures (32, 35, and 37ºC. At all temperatures (except 15ºC, the highest percentage of nymphal mortality was observed in the first instar. The sex ratio was female-biased between 15 and 30ºC, but there was a slightly higher number of males at 32ºC. The highest adult longevities of females and males were obtained at 18 and 25°C, respectively. The pre-oviposition, oviposition, and post-oviposition periods were significantly different at various temperatures. The highest fecundity was observed at 23ºC. The shortest and longest oviposition periods occurred at 32 and 18ºC, respectively. Maximum values of the intrinsic rate of natural increase (rm, net reproduction rate (R0, and finite rate of increase (λ and the shortest mean generation time (T and doubling time (DT were obtained at 25ºC. Our findings showed citrus mealybug performances to be highly affected by temperature.

  7. Development and validation of a Xanthomonas axonopodis pv. citri DNA microarray platform (XACarray generated from the shotgun libraries previously used in the sequencing of this bacterial genome

    Directory of Open Access Journals (Sweden)

    Zaini Paulo A

    2010-05-01

    Full Text Available Abstract Background From shotgun libraries used for the genomic sequencing of the phytopathogenic bacterium Xanthomonas axonopodis pv. citri (XAC, clones that were representative of the largest possible number of coding sequences (CDSs were selected to create a DNA microarray platform on glass slides (XACarray. The creation of the XACarray allowed for the establishment of a tool that is capable of providing data for the analysis of global genome expression in this organism. Findings The inserts from the selected clones were amplified by PCR with the universal oligonucleotide primers M13R and M13F. The obtained products were purified and fixed in duplicate on glass slides specific for use in DNA microarrays. The number of spots on the microarray totaled 6,144 and included 768 positive controls and 624 negative controls per slide. Validation of the platform was performed through hybridization of total DNA probes from XAC labeled with different fluorophores, Cy3 and Cy5. In this validation assay, 86% of all PCR products fixed on the glass slides were confirmed to present a hybridization signal greater than twice the standard deviation of the deviation of the global median signal-to-noise ration. Conclusions Our validation of the XACArray platform using DNA-DNA hybridization revealed that it can be used to evaluate the expression of 2,365 individual CDSs from all major functional categories, which corresponds to 52.7% of the annotated CDSs of the XAC genome. As a proof of concept, we used this platform in a previously work to verify the absence of genomic regions that could not be detected by sequencing in related strains of Xanthomonas.

  8. Description of Sangeeta sinuomacula sp. nov. (Hemiptera: Cicadellidae: Megophthalminae: Agalliini) from Yunnan Province of Southwest China.

    Science.gov (United States)

    Li, Hu; Dai, Ren-Huai; Li, Zi-Zhong

    2015-01-01

    A new species, Sangeeta sinuomacula Li, Dai & Li sp. nov., of tribe Agalliini of subfamily Megophthalminae (Hemiptera: Cicadellidae) is described and illustrated from Yunnnan Province of Southwest China. The new species is easily distinguished from other Sangeeta species by the aedeagal shaft with a pair of slender processes instead of lamelliform lateral expansions. A key to Sangeeta species and updated checklist with distribution are provided.

  9. Studies on idiocerine leafhoppers with descriptions of Chinaocerus gen. nov. and three new species from China (Hemiptera: Cicadomorpha: Cicadellidae).

    Science.gov (United States)

    Dang, Li-Hong; Zhang, Bin; Li, Zi-Zhong

    2016-01-01

    A new leafhopper genus of the tribe Idiocerini (Hemiptera: Cicadomorpha: Cicadellidae), Chinaocerus, is described from the southwest China together with three new species, C. kangdingensis Zhang & Li sp. nov. (Sichuan Province), C. bispinatus Zhang & Li sp. nov. (Yunnan Province) and C. shii Zhang & Li sp. nov. (Sichuan Province). Descriptions and illustrations of these three new species are provided, and a key for their separation is also given.

  10. A revision of the tribe Coelidiini of the Oriental, Palearctic and Australian biogeographical regions (Hemiptera: Cicadellidae: Coelidiinae)

    OpenAIRE

    Nielson, Mervin W.

    2016-01-01

    Within the tribe Coelidiini, subfamily Coelidiinae (Cicadellidae: Hemiptera), fragmentation of the genera Calodia Nielson, Olidiana McKamey and Taharana Nielson established the following 13 new genera: Cladolidia, type-species, Lodiana cladopenis Zhang; Creberulidia, type-species, Calodia paucita Nielson; Glaberana, type-species, Glaberana spadix, sp. nov.; Hamusolidia, type-species, Hamusolidia introrsa, sp. nov.; Hiatusorus, typespecies, Taharana schonhorsti Nielson; Laosolidia, type-specie...

  11. Portanus Ball: descrição de uma espécie nova (Hemiptera, Cicadellidae, Xestocephalinae

    Directory of Open Access Journals (Sweden)

    Adenomar Neves de Carvalho

    2004-01-01

    Full Text Available Portanus dubius sp. nov. é descrita e ilustrada a partir de espécimens que foram coletados com armadilha Malaise durante um levantamento entomológico no Estado do Paraná, Brasil (PROFAUPAR.Portanus Ball: description of a new species (Hemiptera, Cicadellidae, Xestocephalinae. Portanus dubius sp. nov. is described and illustrated. The specimens were collected with Malaise trap during an entomological inventory in Paraná State, Brazil (PROFAUPAR.

  12. The cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae as a new insect pest on tomato plants in Egypt

    Directory of Open Access Journals (Sweden)

    Ibrahim Samah Sayed

    2015-01-01

    Full Text Available Recently, the mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae was recorded as a new pest on tomato plants (Lycopersicon esculentum Mill growing in Egypt. The mealybugs specimens were collected from tomato plants in the Qalyoubia governorate during summer season of 2014. The mealybug was identified as P. solenopsis based on the morphological characters and taxonomic key of this species. This study represents the first record of P. solenopsis as a new insect pest attacking tomato plants in Egypt

  13. Coccophagus scutellaris (Hymenoptera: Aphelinidae): A Highly Effective Biological Control Agent of Soft Scale Insects (Hemiptera: Coccidae) in Egypt

    OpenAIRE

    Shaaban Abd-Rabou

    2011-01-01

    About 953000 individuals of the cosmopolitan parasitoid, Coccophagus scutellaris (Dalman) (Hymenoptera: Aphelinidae), were released and evaluated during 2009-2010 for the control of the following soft scale insects (Hemiptera: Coccidae) infesting the following economic crops in Egypt: Ceroplastes rusci on citrus in Beni Seuf, Ceroplastes floridensis Comstock on citrus in Gharbiya, Coccus hesperidum L. on guava in Giza, Pulvinaria floccifera (Westwood) on mango in Sharqiya, Pulvinaria psidii...

  14. Comparative biology of the two sister species of Triatominae (Hemiptera: Reduviidae Biologia comparativa de duas espécies irmãs de Triatominae (Hemiptera: Reduviidae

    Directory of Open Access Journals (Sweden)

    Ana Laura Carbajal de la Fuente

    2010-02-01

    Full Text Available INTRODUCTION: Triatoma pseudomaculata and T. wygodzinskyi (Hemiptera: Reduviidae: Triatominae are two Brazilian vectors of Chagas disease. The first is an arboricolous species in sylvatic environment and considered a vector of T. cruzi in peridomestic structures; the second, a rupicolous species in the wild environment of no epidemiological importance. In order to test the assumption that sister species share biological traits, comparative studies of their development cycle and blood ingestion were conducted. METHODS: Eggs laid by five field females of each species were randomly selected. The nymphs were observed daily and fed on mice weekly. The time required to pass through the different stages to adulthood was recorded in days. The triatomines were weighed individually before and after feeding. The mortality rate according to each nymphal stage was calculated. RESULTS AND CONCLUSIONS: Analysis of the results shows that they display only minor biological differences even though they exhibit a distinct ecology. This suggests that the biological traits are important criteria to determine the relationship between species.INTRODUÇÃO: Triatoma pseudomaculata e T. wygodzinskyi (Hemiptera: Reduviidae: Triatominae são dois vetores Brasileiros da doença de Chagas. A primeira é uma espécie arborícola em ambiente silvestre e considerada vetor do T. cruzi em estruturas peridomesticas. A segunda é rupícola em ambientes silvestres e sem importância epidemiológica. Com o objetivo de testar a hipótese que espécies irmãs compartilham características semelhantes, realizamos um estudo comparativo do ciclo biológico e ingesta alimentar. MÉTODOS: Ovos pertencentes a cinco fêmeas de cada espécie provenientes do campo foram selecionados aleatoriamente. As ninfas foram observadas diariamente e alimentadas com camundongos semanalmente. O tempo requerido para passar até o estágio adulto foi registrado em dias. Os triatomíneos foram pesados

  15. Desenvolvimento de Dysmicoccus brevipes (Cockerell (Hemiptera:Pseudococcidae em duas cultivares de abacaxi Development of the pineapple mealybug Dysmicoccus brevipes (Cockerell (Hemiptera: Pseudococcidae on two pineapple cultivars

    Directory of Open Access Journals (Sweden)

    Lenira Viana Costa Santa-Cecília

    2004-10-01

    Full Text Available A cochonilha Dysmicoccus brevipes (Cockerell (Hemiptera: Pseudococcidae é uma das principais pragas em cultivos de abacaxi e os estudos biológicos desse inseto em diferentes cultivares são uma necessidade. Objetivou-se com este trabalho avaliar o desenvolvimento dessa cochonilha em duas cultivares de abacaxi, Pérola e Cayenne. O experimento foi conduzido em câmara climatizada a 25 ± 1ºC, 70 ± 10% UR e fotofase de 12 horas. As plantas de abacaxi foram reproduzidas in vitro, transplantadas para vasos (250 mL e aclimatadas em casa-de-vegetação. Ninfas com até um dia de vida foram confinadas em gaiolas de PVC (1 cm de diâmetro, e fixadas em folhas de ambas as cultivares. Não foram detectadas diferenças no desenvolvimento de D. brevipes nos dois substratos alimentares utilizados. O desenvolvimento ninfal de fêmeas e machos de D. brevipes foi 39,9 e 32,0 dias na cv. Pérola e 38,5 e 32,4 dias na cv. Cayenne, respectivamente. A sobrevivência da fase ninfal foi 32,3 e 40,5%; a razão sexual, 0,39 e 0,33; e a longevidade de fêmeas, 20,3 e 26,1 dias nas cvs. Pérola e Cayenne, respectivamente.The pineapple mealybug Dysmicoccus brevipes (Cockerell (Hemiptera: Pseudococcidae is the main pest on pineapple crops and biological studies of this insect are necessary on different cultivars. The objective of this work was to evaluate the development time of this mealybug on the pineapple cultivars Pérola and Cayenne. The experiment was performed in climated chambers at 25 ± 1ºC, 70 ± 10% RH and 12 h photophase. Pinneapple plants were reproduced in vitro, transplanted to pots (250 mL and kept in greenhouse. One-day-old nymphs were kept inside a clipcage (1 cm diameter fixed on the plants. No differences in development of D. brevipes among the cultivars were found. Development times of females and males, respectively, were 39.9 and 32 days on cv. Pérola and 38.5 and 32.4 days on cv. Cayenne. Nymphs survivals were 32.3 and 40.5%, sexual rates

  16. Rapid screening and identification of compounds with DNA-binding activity from Folium Citri Reticulatae using on-line HPLC-DAD-MS(n) coupled with a post column fluorescence detection system.

    Science.gov (United States)

    Fu, Qingrong; Zhang, Cangman; Lin, Zongtao; Sun, Hongyang; Liang, Yi; Jiang, Haixiu; Song, Zhiling; Wang, Hong; Chen, Shizhong

    2016-02-01

    To study the interactions between natural compounds and deoxyribonucleic acid (DNA), a method has been established combining a high-performance liquid chromatography-diode array detector-multi-stage mass spectrometer with a fluorescence detector (HPLC-DAD-MS(n)-FLD). The FLD was used to monitor fluorescence intensity of the ethidium bromide-DNA (EB-DNA) complex when a compound separated by HPLC was introduced. This novel method was used to simultaneously obtain the HPLC fingerprint, UV spectra, MS(n) fragments and DNA-binding activity profile of various components in Folium Citri Reticulatae. As a result, 35 compounds were identified, of which 25 were found in the extract of Folium Citri Reticulatae for the first time, and 33 compounds showed DNA-binding activities, with the most active being feruloylhexaric and p-coumaroylhexaric acids. In addition, the precision, stability and reproducibility of this method were validated by two positive controls, quercetin and hesperidin. This new on-line method is accurate, precise and reliable for further high-throughput screening of DNA-binding compounds from food samples and other complex matrices.

  17. Advances in the use of the RNA interference technique in Hemiptera

    Institute of Scientific and Technical Information of China (English)

    Jie Li; Xiao-Ping Wang; Man-Qun Wang; Wei-Hua Ma; Hong-Xia Hua

    2013-01-01

    RNA interference(RNAi)suppresses the expression of target genes by posttranscriptional regulation.Because double-stranded RNA(dsRNA)mediated gene silencing is a conserved mechanism in many eukaryotes,RNAi has become a valuable tool for unveiling gene function in many model insects.Recent research has also shown that RNAi can also be effective in the downregulation of target genes in Hemiptera.In this review,we discuss the use of the RNAi technique in gene functional analysis in hemipterans,highlighting the methods of dsRNA uptake by these insects and discuss the knock-down efficiency of these techniques.Although the RNAi technique has disadvantages,our primary goal here is to determine whether it can be exploited further in the discovery of new gene functions,and as a pest control strategy,in some important Hemipteran pests.

  18. Phylogenetic signals from Nepomorpha (Insecta: Hemiptera: Heteroptera) mouthparts: stylets bundle, sense organs, and labial segments.

    Science.gov (United States)

    Brożek, Jolanta

    2014-01-01

    The present study is a cladistic analysis of morphological characters focusing on the file of the mandible, the apices of the maxillae, the rupturing device on the maxillae, the internal structures of the mouthparts, and the external morphology of the labial segments as well as the distribution of labial sensilla in true water bugs (Hemiptera: Heteroptera, infraorder Nepomorpha). The study is based on data referring to sixty-two species representing all nepomorphan families (Heteroptera), together with one outgroup species representing the infraorders Gerromorpha (Mesoveliidae). The morphological data matrix consists of forty-eight characters. The present hypothesis supports the monophyly of the Nepomorpha and the monophyly of all families. The new modification in the systematic classification has been proposed: ((Nepidae + Belostomatidae), (Diaprepocoridae + Corixidae + Micronectidae), (Ochteridae + Gelastocoridae), Aphelocheiridae, Potamocoridae, Naucoridae, Notonectidae, and (Pleidae + Helotrephidae)).

  19. Phylogenetic Signals from Nepomorpha (Insecta: Hemiptera: Heteroptera Mouthparts: Stylets Bundle, Sense Organs, and Labial Segments

    Directory of Open Access Journals (Sweden)

    Jolanta Brożek

    2014-01-01

    Full Text Available The present study is a cladistic analysis of morphological characters focusing on the file of the mandible, the apices of the maxillae, the rupturing device on the maxillae, the internal structures of the mouthparts, and the external morphology of the labial segments as well as the distribution of labial sensilla in true water bugs (Hemiptera: Heteroptera, infraorder Nepomorpha. The study is based on data referring to sixty-two species representing all nepomorphan families (Heteroptera, together with one outgroup species representing the infraorders Gerromorpha (Mesoveliidae. The morphological data matrix consists of forty-eight characters. The present hypothesis supports the monophyly of the Nepomorpha and the monophyly of all families. The new modification in the systematic classification has been proposed: ((Nepidae + Belostomatidae, (Diaprepocoridae + Corixidae + Micronectidae, (Ochteridae + Gelastocoridae, Aphelocheiridae, Potamocoridae, Naucoridae, Notonectidae, and (Pleidae + Helotrephidae.

  20. Survival and fecundity of two strains of Cimex lectularius (Hemiptera: Heteroptera).

    Science.gov (United States)

    Barbarin, Alexis M; Barbarin, Alexis M; Barbu, Corentin M; Gebhardtsbauer, Ron; Rajotte, Edwin G

    2014-09-01

    Knowledge of development of the bed bug Cimex lectularius L. (Hemiptera: Heteroptera) under specific environmental conditions could lead to improved management techniques. Developmental rates, age-, and stage-specific life tables were compared for a laboratory strain and a field strain of bed bugs reared on human blood. Both strains were then crossed reciprocally to produce four F1 generations and subsequent age- and stage-specific life tables were constructed. No significant differences were found in the overall survival of the parental strains, but significant differences were found in development rate within various instars based on strain. Parallel results were derived from the F1 generation hybrids. Stable age distribution calculations predict that 80% of bedbugs within exponentially growing populations will be immature.

  1. Leaf Damaged by Nymph of Cardiaspina albitextura and Cardiaspina retator (Hemiptera: Psyllidae

    Directory of Open Access Journals (Sweden)

    NISMAH

    2008-06-01

    Full Text Available Cardispina (Hemiptera: Pshyllidae is one of the most important genera of the Australian Psyllidae, owing to the spectacular damage to Eucalyptus spp. The increase of C. albitextura and C. retator populations in high numbers caused severe damage on leaves of Eucalyptus camaldulensis. Both species have similarities, i.e. they occur on the same host plant and prefer mature leaves of E. camaldulensis for oviposition and feeding sites. They might thus be more likely to show competition than the less closely related taxa. The purpose of the study was to examine degree of the resource use by measuring the area of leaves damaged by the nymphs of C. albitextura and C. retator. The results indicated that the nymph of C. retator caused damage twice more damages than that of C. albitextura. The leaves area damaged by the females of both species was greater than that by the males.

  2. Egg parasitoids of Taosa spp. (Hemiptera: Dictyopharidae in Formosa, Argentina, with descriptions of two new species

    Directory of Open Access Journals (Sweden)

    Serguei V. TRIAPITSYN

    2011-01-01

    Full Text Available Se revisaron los parasitoides oófagos (Hymenoptera: Eulophidae y Platygastridae de Taosa (Cuernavaca longula Remes Lenicov (Hemiptera: Dictyopharidae y se presenta una clave para su identificación. Este dictiofárido se alimenta de camalote, Eichhornia crassipes (Martius Solms-Laubach, y fue colectado en Formosa, Argentina, donde algunos de sus huevos estaban parasitados. Se describen dos especies nuevas: Aprostocetus (Ootetrastichus taosae Triapitsyn, sp. nov. (Eulophidae: Tetrastichinae y Telenomus formosanus Triapitsyn, sp. nov. (Platygastridae: Telenominae. La última especie, que pertenece al grupo crassiclava de especies de Telenomus Haliday, también ataca los huevos de Taosa sp. sobre Pontederia subovata (Seubert Lowden. Estos son los primeros parasitoides oófagos registrados para el género Taosa Distant.

  3. An annotated update of the scale insect checklist of Hungary (Hemiptera, Coccoidea

    Directory of Open Access Journals (Sweden)

    Ferenc Kozár

    2013-06-01

    Full Text Available The number of scale insect species (Hemiptera: Coccoidea known from Hungary has increased in the last 10 years by 39 (16.6 %, to a total of 274 species belonging to 112 genera in10 families. The family Pseudococcidae is the most species rich, with 101 species in 34 genera; Diaspididae contains 59 species in 27 genera; Coccidae contains 54 species in 27 genera; and the Eriococcidae contains 33 species in 8 genera. The other 6 coccoid families each contain only a few species: Asterolecaniidae (7 species in 3 genera; Ortheziidae (7 species in 4 genera; Margarodidae sensu lato (5 species in 5 genera; Cryptococcidae (3 species in 2 genera; Kermesidae (4 species in 1genus; and Cerococcidae (1 species. Of the species in the check list, 224 were found in outdoor conditions, while 50 species occurred only in indoor conditions. This paper contains 22 species recorded for the first time in the Hungarian fauna.

  4. Are Phenacoccus solani Ferris and P. defectus Ferris (Hemiptera: Pseudococcidae) distinct species?

    Science.gov (United States)

    Chatzidimitriou, Evangelia; Simonato, Mauro; Watson, Gillian W; Martinez-Sañudo, Isabel; Tanaka, Hirotaka; Zhao, Jing; Pellizzari, Giuseppina

    2016-03-24

    Among the Nearctic species of Phenacoccus (Hemiptera: Pseudococcidae), Phenacoccus solani Ferris and P. defectus Ferris are morphologically similar and it can be difficult to separate them on the basis of microscopic morphological characters of the adult female alone. In order to resolve their identity, a canonical variates morphological analysis of 199 specimens from different geographical origins and host plants and a molecular analysis of the COI and 28S genes were performed. The morphological analysis supported synonymy of the two species, as although the type specimens of the "species" are widely separated from each other in the canonical variates plot, they are all part of a continuous range of variation. The molecular analysis showed that P. solani and P. defectus are grouped in the same clade. On the basis of the morphological and molecular analyses, P. defectus is synonymized under the senior name P. solani, syn. n.

  5. The structure of integument and wax glands of Phenacoccus fraxinus (Hemiptera: Coccoidea: Pseudococcidae).

    Science.gov (United States)

    Zhang, Yanfeng; Xie, Yingping; Xue, Jiaoliang; Fu, Xiaohong; Liu, Weimin

    2012-06-01

    Using scanning electron microscopy and optical microscopy, we studied the structure of the integument and wax glands of the mealybug, Phenacoccus fraxinus Tang (Hemiptera: Coccoidea: Pseudococcidae). We observed the ultrastructure of four wax pores including trilocular, quinquelocular, and multilocular pores as well as tubular ducts, recording characteristics of their structure, size and distribution. We found that that the integument of the mealybug consists of three main layers-the procuticle, epidermis and basement membrane-and four sub-layers of the procuticle-the epicuticle, exocuticle, endocuticle and formation zone. The wax-secreting gland cells were closely arranged in epidermis. All of them were complex and composed of one central cell and two or more lateral cells. These complex cells possess a large common reservoir for collection and storage. Synthesized by the glandular cells, the wax is excreted outside integument through canals.

  6. Chirality and bioactivity of the sex pheromone of Madeira mealybug (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Ho, Hsiao-Yung; Ko, Chi-Hung; Cheng, Chao-Chih; Su, Yu-Ting; Pola, Someshwar

    2011-06-01

    Two compounds (trans-1R,3R-chrysanthemyl R-2-methylbutanoate and R-lavandulyl R-2-methylbutanoate) identified from aeration extracts of virgin female Madeira mealybug, Phenacoccus madeirensis Green (Hemiptera: Pseudococcidae), were synthesized and tested in field bioassays in northern Taiwan over a 1-mo period. In total, 1,492 male P. madeirensis were captured in sticky traps. Our results showed that 1 microg of synthetic trans-1R,3R-chrysanthemyl R-2-methylbutanoate released from a plastic tube dispenser was attractive to the mealybugs. Different stereoisomers of chrysanthemyl 2-methylbutanoate also were tested. The insect-produced stereoisomer was the most attractive of all the isomers tested, and the stereochemistry of the acid moiety proved to be more critical than that of the alcohol moiety. The minor component found in extracts, R-lavandulyl R-2-methylbutanoate, alone was not attractive to male Madeira mealybugs nor did it act synergistically or additively with the main component.

  7. A survey of scale insects in soil samples from Europe (Hemiptera, Coccomorpha).

    Science.gov (United States)

    Kaydan, Mehmet Bora; Benedicty, Zsuzsanna Konczné; Kiss, Balázs; Szita, Éva

    2016-01-01

    In the last decades, several expeditions were organized in Europe by the researchers of the Hungarian Natural History Museum to collect snails, aquatic insects and soil animals (mites, springtails, nematodes, and earthworms). In this study, scale insect (Hemiptera: Coccomorpha) specimens extracted from Hungarian Natural History Museum soil samples (2970 samples in total), all of which were collected using soil and litter sampling devices, and extracted by Berlese funnel, were examined. From these samples, 43 scale insect species (Acanthococcidae 4, Coccidae 2, Micrococcidae 1, Ortheziidae 7, Pseudococcidae 21, Putoidae 1 and Rhizoecidae 7) were found in 16 European countries. In addition, a new species belonging to the family Pseudococcidae, Brevennia larvalis Kaydan, sp. n. and a new species of Ortheziidae, Ortheziola editae Szita & Konczné Benedicty, sp. n. are described and illustrated based on the adult female stage. Revised keys to the adult females of Brevennia and Ortheziola are presented.

  8. Genome sequence of "Candidatus Walczuchella monophlebidarum" the flavobacterial endosymbiont of Llaveia axin axin (Hemiptera: Coccoidea: Monophlebidae).

    Science.gov (United States)

    Rosas-Pérez, Tania; Rosenblueth, Mónica; Rincón-Rosales, Reiner; Mora, Jaime; Martínez-Romero, Esperanza

    2014-03-01

    Scale insects (Hemiptera: Coccoidae) constitute a very diverse group of sap-feeding insects with a large diversity of symbiotic associations with bacteria. Here, we present the complete genome sequence, metabolic reconstruction, and comparative genomics of the flavobacterial endosymbiont of the giant scale insect Llaveia axin axin. The gene repertoire of its 309,299 bp genome was similar to that of other flavobacterial insect endosymbionts though not syntenic. According to its genetic content, essential amino acid biosynthesis is likely to be the flavobacterial endosymbiont's principal contribution to the symbiotic association with its insect host. We also report the presence of a γ-proteobacterial symbiont that may be involved in waste nitrogen recycling and also has amino acid biosynthetic capabilities that may provide metabolic precursors to the flavobacterial endosymbiont. We propose "Candidatus Walczuchella monophlebidarum" as the name of the flavobacterial endosymbiont of insects from the Monophlebidae family.

  9. An annotated checklist of scale insects (Hemiptera: Coccoidea) of Saint Lucia, Lesser Antilles .

    Science.gov (United States)

    Malumphy, Chris

    2014-07-31

    An annotated list of 83 scale insect species (Hemiptera: Sterorrhyncha: Coccoidea) recorded from Saint Lucia is presented, based on data gathered from UK quarantine interceptions, samples collected in an urban coastal habitat in the North West of the Island in 2013, and published records. Thirty-three species (40%) are recorded for the first time for the country, including Dysmicoccus joannesiae (Costa Lima), a South American mealybug, and Poliaspoides formosana (Takahashi), an Asian armoured scale insect pest of bamboo, which are new for the Caribbean region. The economic, environmental and social impacts caused by introduced exotic species of scale insect are discussed. Two predatory midges Diadiplosis ?coccidivora (Felt) and Diadiplosis multifila (Felt) (Diptera: Cecidomyiidae) are recorded for the first time from Saint Lucia. The latter species was observed causing 90% mortality of a large infestation of passion vine mealybug Planococcus minor (Maskell) on soursop fruit. 

  10. An annotated update of the scale insect checklist of Hungary (Hemiptera, Coccoidea).

    Science.gov (United States)

    Kozár, Ferenc; Benedicty, Zsuzsanna Konczné; Fetykó, Kinga; Kiss, Balázs; Szita, Eva

    2013-01-01

    The number of scale insect species (Hemiptera: Coccoidea) known from Hungary has increased in the last 10 years by 39 (16.6 %), to a total of 274 species belonging to 112 genera in10 families. The family Pseudococcidae is the most species rich, with 101 species in 34 genera; Diaspididae contains 59 species in 27 genera; Coccidae contains 54 species in 27 genera; and the Eriococcidae contains 33 species in 8 genera. The other 6 coccoid families each contain only a few species: Asterolecaniidae (7 species in 3 genera); Ortheziidae (7 species in 4 genera); Margarodidaesensu lato (5 species in 5 genera); Cryptococcidae (3 species in 2 genera); Kermesidae (4 species in 1genus); and Cerococcidae (1 species). Of the species in the check list, 224 were found in outdoor conditions, while 50 species occurred only in indoor conditions. This paper contains 22 species recorded for the first time in the Hungarian fauna.

  11. On dorsal prothoracic appendages in treehoppers (Hemiptera: Membracidae and the nature of morphological evidence.

    Directory of Open Access Journals (Sweden)

    István Mikó

    Full Text Available A spectacular hypothesis was published recently, which suggested that the "helmet" (a dorsal thoracic sclerite that obscures most of the body of treehoppers (Insecta: Hemiptera: Membracidae is connected to the 1st thoracic segment (T1; prothorax via a jointed articulation and therefore was a true appendage. Furthermore, the "helmet" was interpreted to share multiple characteristics with wings, which in extant pterygote insects are present only on the 2nd (T2 and 3rd (T3 thoracic segments. In this context, the "helmet" could be considered an evolutionary novelty. Although multiple lines of morphological evidence putatively supported the "helmet"-wing homology, the relationship of the "helmet" to other thoracic sclerites and muscles remained unclear. Our observations of exemplar thoraces of 10 hemipteran families reveal multiple misinterpretations relevant to the "helmet"-wing homology hypothesis as originally conceived: 1 the "helmet" actually represents T1 (excluding the fore legs; 2 the "T1 tergum" is actually the anterior dorsal area of T2; 3 the putative articulation between the "helmet" and T1 is actually the articulation between T1 and T2. We conclude that there is no dorsal, articulated appendage on the membracid T1. Although the posterior, flattened, cuticular evagination (PFE of the membracid T1 does share structural and genetic attributes with wings, the PFE is actually widely distributed across Hemiptera. Hence, the presence of this structure in Membracidae is not an evolutionary novelty for this clade. We discuss this new interpretation of the membracid T1 and the challenges of interpreting and representing morphological data more broadly. We acknowledge that the lack of data standards for morphology is a contributing factor to misinterpreted results and offer an example for how one can reduce ambiguity in morphology by referencing anatomical concepts in published ontologies.

  12. On dorsal prothoracic appendages in treehoppers (Hemiptera: Membracidae) and the nature of morphological evidence.

    Science.gov (United States)

    Mikó, István; Friedrich, Frank; Yoder, Matthew J; Hines, Heather M; Deitz, Lewis L; Bertone, Matthew A; Seltmann, Katja C; Wallace, Matthew S; Deans, Andrew R

    2012-01-01

    A spectacular hypothesis was published recently, which suggested that the "helmet" (a dorsal thoracic sclerite that obscures most of the body) of treehoppers (Insecta: Hemiptera: Membracidae) is connected to the 1st thoracic segment (T1; prothorax) via a jointed articulation and therefore was a true appendage. Furthermore, the "helmet" was interpreted to share multiple characteristics with wings, which in extant pterygote insects are present only on the 2nd (T2) and 3rd (T3) thoracic segments. In this context, the "helmet" could be considered an evolutionary novelty. Although multiple lines of morphological evidence putatively supported the "helmet"-wing homology, the relationship of the "helmet" to other thoracic sclerites and muscles remained unclear. Our observations of exemplar thoraces of 10 hemipteran families reveal multiple misinterpretations relevant to the "helmet"-wing homology hypothesis as originally conceived: 1) the "helmet" actually represents T1 (excluding the fore legs); 2) the "T1 tergum" is actually the anterior dorsal area of T2; 3) the putative articulation between the "helmet" and T1 is actually the articulation between T1 and T2. We conclude that there is no dorsal, articulated appendage on the membracid T1. Although the posterior, flattened, cuticular evagination (PFE) of the membracid T1 does share structural and genetic attributes with wings, the PFE is actually widely distributed across Hemiptera. Hence, the presence of this structure in Membracidae is not an evolutionary novelty for this clade. We discuss this new interpretation of the membracid T1 and the challenges of interpreting and representing morphological data more broadly. We acknowledge that the lack of data standards for morphology is a contributing factor to misinterpreted results and offer an example for how one can reduce ambiguity in morphology by referencing anatomical concepts in published ontologies.

  13. Effects of temperature and food on the development of Dysdercus maurus Distant (Hemiptera, Pyrrhocoridae); Efeitos da temperatura e do alimento no desenvolvimento de Dysdercus maurus Distant (Hemiptera, Pyrrhocoridae)

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Fabio Souto [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Dept. de Ciencias Ambientais], e-mail: fbio_almeida@yahoo.com.br; Goncalves, Lenicio [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Dept. de Biologia Animal. Area de Biologia], e-mail: lencygon@globo.com

    2007-10-15

    Dysdercus maurus Distant, 1901 (Hemiptera, Pyrrhocoridae) is an important pest on Gossypium spp. (cotton tree), Citrus sinensis Osbeck (Rutaceae) and Citrus reticulata Blanco (Rutaceae) crops. This insect also feeds on seeds of Chorisia speciosa St. Hil. (Bombacaceae). This work aimed to evaluate the effects of temperature and food on the development of D. maurus. Eight treatments were carried out, in six of them bugs were fed with seeds of C. speciosa and kept at 15, 18, 20, 25 and 30 {+-} 1 deg C, 80 {+-} 3% RH and 12h photo phase or in laboratory conditions (23.5 {+-} 2.6 deg C, 73.3 {+-} 9.9 % RH), and in the other two treatments bugs were fed with seeds of cotton variety IAC-22 and kept at 25 or 30 deg C. In all treatments five immature stages were observed. The increase of temperature caused reduction in the developmental time. The temperature of 15 deg C disabled nymphal eclosion and was also lethal to those nymphs ecloded at other temperatures. The lower mortality of nymphs occurred in the temperature of 25 deg C with cotton as food (24.07%). The lower threshold temperature (Tb) occurred for the first instar (11.54 deg C) and the higher for the second instar (15.33 deg C). The females of D. maurus required more degree-days (329.93 degree-days) than males (300.49 degree-days) until adult emergence. (author)

  14. First report and morphological redescription of Teleonemia morio (Stål (Hemiptera, Tingidae in Annona squamosa L. (Annonaceae in Brazil

    Directory of Open Access Journals (Sweden)

    Sônia M. F. Broglio

    2012-03-01

    Full Text Available First report and morphological redescription of Teleonemia morio (Stål (Hemiptera, Tingidae in Annona squamosa L. (Annonaceae in Brazil. This is the first report of a severe attack of Teleonemia morio (Stål, 1855 (Hemiptera, Heteroptera, Tingidae on Annona squamosa L. (custard apple, causing up to 80% of losses of infested trees. In order to facilitate the identification of this insect pest, the adult female of T. morio is redescribed based on specimens collected in Palmeira dos Índios, Alagoas, Brazil.

  15. Study on Infrared Fingerprint of Exocarpium Citri Grandis with Different Species%化橘红药材红外指纹图谱的研究

    Institute of Scientific and Technical Information of China (English)

    卢丽萍; 林励; 黄爱华; 欧立娟; 汪金玉

    2011-01-01

    Objective To provide theoretical basis and practical methods for the rapid identification of Exocarpium Citri Grandis (ECG) with different species. Methods The fingerprints were established by fourier transform ifrared spectroscopy(FTIR), and then were analyzed by Spectrum v5.0.1 software. Results With normalization of the selected points between 1,820 cm-1 and 950 cm-1 on the FTIR fingerprints of ECG powder, significant differences were shown, and the second derivative spectra of the two different species between 1,800 cm-1 and 700 cm-1 had significant differences, which can be taken as one of the major identical characteristics to distinguish the two species. Conclusion The FTIR fingerprints is effective and feasible for the identification of the two species of ECG.%目的 建立化橘红药材的红外指纹图谱,通过考察不同品种化橘红药材的红外指纹图谱差异,为化橘红药材的快速鉴别提供理论依据和实用方法.方法 采用傅里叶红外光谱法(FTIR)建立不同品种化橘红药材红外指纹图谱,应用Spectrum v5.0.1红外软件对实验数据进行处理.结果 FTIR图谱在1820~950 cm-1范围内选点归一化处理后毛橘红和光橘红差异显著,其在1800~700 cm-1范围内二阶导数谱差异亦显著,可作为两者主要鉴别特征,经处理后的FTIR指纹图谱能有效鉴别两类化橘红药材.结论 红外指纹图谱法鉴别化橘红快速、简便、可行,可有效区分毛橘红和光橘红.

  16. 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

    Directory of Open Access Journals (Sweden)

    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

  17. Complete Genome Sequences of the Obligate Symbionts "Candidatus Sulcia muelleri" and "Ca. Nasuia deltocephalinicola" from the Pestiferous Leafhopper Macrosteles quadripunctulatus (Hemiptera: Cicadellidae).

    Science.gov (United States)

    Bennett, Gordon M; Abbà, Simona; Kube, Michael; Marzachì, Cristina

    2016-01-01

    Two bacterial symbionts of the European pest leafhopper, Macrosteles quadripunctulatus (Hemiptera: Cicadellidae), were fully sequenced. "Candidatus Sulcia muelleri" and "Ca. Nasuia deltocephalinicola" represent two of the smallest known bacterial genomes at 190 kb and 112 kb, respectively. Genome sequences are nearly identical to strains reported from the closely related host species, M. quadrilineatus.

  18. First record of the leafhopper genus Zyginopsis Ramakrishnan & Menon (Hemiptera: Cicadellidae: Typhlocybinae: Erythroneurini) from China, with descriptions of two new species.

    Science.gov (United States)

    Jiang, Hao; Zhang, Yalin

    2016-01-01

    The erythroneurine leafhopper genus Zyginopsis Ramakrishnan & Menon (Hemiptera: Cicadellidae: Typhlocybinae) is reported for the first time from China, with descriptions and illustrations of two new species, Zyginopsis paraverticalis and Zyginopsis gracilis spp. nov., and one newly recorded species from China, Zyginopsis verticalis Ahmed n. rec. A key for identification of Chinese species (adult males) is provided.

  19. Characterization of EPG waveforms for the tea green leafhopper, Empoasca vitis Göthe (Hemiptera: Cicadellidae), on tea plants and their correlation with stylet activities

    Science.gov (United States)

    Stylet probing activities of the tea green leafhopper, Empoasca vitis Göthe (Hemiptera: Cicadellidae), were studied using the DC electrical penetration graph (EPG) technique. Seven different EPG waveforms (i.e., Np, E1, E2, E3, E4, E5 and E6) were identified and characterized on susceptible tea leav...

  20. Knockdown and lethal effects of eight commercial nonconventional and two pyrethroid insecticides against moderately permethrin-resistant adult bed bugs, Cimex lectularius (L.) (Hemiptera: Cimicidae)

    Science.gov (United States)

    The common bed bug, Cimex lectularius (L.) (Hemiptera: Cimicidae) is undergoing a rapid resurgence in the United States during the last decade which has created a notable pest management challenge largely because the pest has developed resistance against DDT, organophosphates, carbamates, and pyreth...

  1. Can we predict brown stink bug (Hemiptera: Pentatomidae) abundance in corn using previous pheromone trap capture and early season weather data?

    Science.gov (United States)

    Brown stink bug, Euschistus servus (Say) (Hemiptera: Pentatomidae), is a serious economic pest of corn production in the southern US. Scouting stink bugs in corn is time consuming and could be improved if scouts were aware of conditions that favored imminent stink bug infestations. Changes in seas...

  2. Praon volucre (Hymenoptera: Braconidae: Aphidiinae), a natural enemy of Macrosiphum euphorbiae (Hemiptera: Aphididae): Life table and intrinsic rate of population increase

    NARCIS (Netherlands)

    Lins, J.C.; Bueno, V.H.P.; Silva, D.B.; Sampaio, M.V.; Lenteren, van J.C.

    2011-01-01

    Life table data of natural enemies are often used to understand their population dynamics and estimate their potential role in the biological control of pests. Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae) is an important pest of several crops and its intrinsic rate of population increase (

  3. A study of the scale insect genera Puto Signoret (Hemiptera: Sternorrhyncha: Coccoidea: Putoidae) and Ceroputo Šulc (Pseudococcidae) with a comparison to Phenacoccus Cockerell (Pseudococcidae)

    Science.gov (United States)

    For almost a century, the scale insect genus Puto Signoret (Hemiptera: Sternorrhyncha: Coccoidea) was considered to belong to the family Pseudococcidae (the mealybugs), but recent consensus accords Puto its own family, the Putoidae. This paper reviews the taxonomic history of Puto and family Putoida...

  4. Use of Electrical Penetration Graph Technology to Examine Transmission of ‘Candidatus Liberibacter solanacearum’ to Potato by Three Haplotypes of Potato Psyllid (Bactericera cockerelli; Hemiptera: Triozidae)

    Science.gov (United States)

    The potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae), is a vector of the phloem-limited bacterium ‘Candidatus Liberibacter solanacearum’ (Lso), the putative causal agent of zebra chip disease of potato. Little is known about how potato psyllid transmits Lso to potato. We used ele...

  5. Pre shipping dip treatments using soap, natural oils, and Isaria fumosorosea: potential biopesticides for mitigating the spread of whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) invasive insects on ornamental plants

    Science.gov (United States)

    The whitefly Bemisia tabaci (Hemiptera: Aleyodidae) is an invasive insect pest affecting different crops including vegetables, fruits, cereals, and ornamentals. The efficacy of some products such as commercial soap, natural oils and Preferal® (based on the entomopathogenic fungus Isaria fumosorosea ...

  6. Characterization of twelve novel microsatellite markers of Sogatella furcifera (Horváth) (Hemiptera: Delphacidae) identified from next generation sequence data

    Science.gov (United States)

    The white-backed planthopper, Sogatella furcifera (Horváth) (Hemiptera: Delphacidae), is a major pest of rice and has long-range migratory behavior in Asia. Microsatellite markers (simple sequence repeats, SSRs) have been widely used to determine the origins and genetic diversity of insect pests. ...

  7. Repellency of mustard (Brassica juncea) and arugula (Eruca sativa) plants, and plant oils against the sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an economic complex of at least 36 cryptic species, comprising a highly polyphagous and serious pest of vegetable, fiber and ornamental crops. Sustainable alternative measures such as cultural controls can be effective ...

  8. Investigation on the resistance of different varieties of citrus to Xanthomonas citri%不同柑橘品种对柑橘溃疡病的抗性调查

    Institute of Scientific and Technical Information of China (English)

    宋盛英; 杨光兰; 潘盛勇; 赵春穆; 石安鸠

    2002-01-01

    通过柑橘Citrus sp.4类10个品种对柑橘溃疡病Xanthomonas citri(Hasse)Dowson抗病性的调查发现,不同的柑橘品种对柑橘溃疡病的抗病程度有明显差异,甜橙类、脐橙类普遍容易感病,属高度感病品种;宽皮橘类的抗病性最强;而柚类感病轻重不一,以台湾白柚抗病性最强,而沙田柚抗病性较弱.

  9. First occurrence of Alcaeorrhynchus grandis (Dallas) (Hemiptera: Pentatomidae) preying on defoliating caterpillars of oil palm in the state of Para, Brazil; Primeira ocorrencia de Alcaeorrhynchus grandis (Dallas) (Hemiptera: Pentatomidae) predando lagartas desfolhadoras do dendezeiro no estado do Para, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Rafael C.; Lemos, Walkymario P.; Muller, Antonio A. [EMBRAPA Amazonia Oriental, Belem, PA (Brazil). Lab. de Entomologia], e-mail: rafaufra@yahoo.com.br, e-mail: wplemos@cpatu.embrapa.br; Muller, Antonio A. [Embrapa Amazonia Oriental, Belem, PA (Brazil). Lab. de Entomologia; Bernardino, Aline S.; Buecke, Joel [Grupo Agropalma S/A., Tailandia, PA (Brazil)

    2010-01-15

    The oil palm Elaeis guineensis is usually attacked by pests, particularly, defoliating caterpillars. Between 2004 and 2006 a stinkbug predator (Asopinae) was registered preying on caterpillars of Brassolis sophorae L., Opsiphanes invirae Hubner (Lepidoptera: Nymphalidae) and Sibine spp. (Lepidoptera: Limacodidae), reducing their populations in commercial oil palm plantations in the State of Para, Brazil. Specimens of the natural enemy were collected, mounted, and identified as Alcaeorrhynchus grandis (Dallas) (Hemiptera: Pentatomidae), corresponding to the first report of the occurrence of this stinkbug attacking defoliating caterpillars of oil palm in Brazil. (author)

  10. 柑橘全爪螨微卫星位点鉴定与信息分析%Analysis of Microsatellite Loci fromPanonychus citri Based on Enriched Microsatellite Library and Transcriptome Dataset

    Institute of Scientific and Technical Information of China (English)

    魏丹丹; 刘燕; 杜洋; 李刚; 李婷; 袁明龙; 王进军

    2016-01-01

    重复类型,占总数的53.86%;其次为两碱基核心重复类型,占总数的43.36%;而四、五、六碱基重复类型以及复合型的SSR数量均较少,且数量差异不大,共占EST-SSR总数的2.78%。柑橘全爪螨EST-SSR核心重复次数主要集中在5—10次。【结论】采用磁珠富集法,并将酶切、接头连接一步化,可提高个体微小的螨类及微小昆虫SSR的富集效率。柑橘全爪螨gSSR核心重复次数要远多于从转录组数据库获得的EST-SSR。总体而言,gSSR和EST-SSR中的三碱基重复SSR具有更好的优化率。此外,柑橘全爪螨gSSR具有微卫星家族现象。%Objective] The objective of this study is to construct the microsatellite-enriched libraries, and identify genomic- microsatellite (gSSR) from the genome of the citrus red mite,Panonychus citri. Meanwhile, a large number of gene-microsatellite (EST-SSR) markers were also indentified from the transcriptome database ofP. citri. Based on these SSR sequences, the selected SSR primer pairs were validated.[Method]On the basis of isolating high quality genomic DNA ofP. citri, enriched microsatellite libraries were constructed by streptavidin-coated magnetic beads utilizing methodologies that exploit the strong affinity between biotin and the protein streptavidin. A fast and easy protocol was proposed through a combination of two different published methods. Briefly, genomic DNA was digested by the restriction enzyme and then ligated to designed adaptors. Microsatellite-containing DNA fragments were captured by streptavidin-coated magnetic beads. The beads affinity capture of microsatellite repeats using biotinylated oligonucleotide probes. Subsequently, PCR was used to amplify the captured molecules for transferring single strand DNA to double strand DNA. The PCR products were then ligated to pGEM-T Easy vector and transformed into Trans5α competent cells. Then, clones from these libraries were screened for microsatellite content. Meanwhile

  11. Organization of the mitochondrial genomes of whiteflies, aphids, and psyllids (Hemiptera, Sternorrhyncha

    Directory of Open Access Journals (Sweden)

    Baumann Paul

    2004-08-01

    Full Text Available Abstract Background With some exceptions, mitochondria within the class Insecta have the same gene content, and generally, a similar gene order allowing the proposal of an ancestral gene order. The principal exceptions are several orders within the Hemipteroid assemblage including the order Thysanoptera, a sister group of the order Hemiptera. Within the Hemiptera, there are available a number of completely sequenced mitochondrial genomes that have a gene order similar to that of the proposed ancestor. None, however, are available from the suborder Sternorryncha that includes whiteflies, psyllids and aphids. Results We have determined the complete nucleotide sequence of the mitochondrial genomes of six species of whiteflies, one psyllid and one aphid. Two species of whiteflies, one psyllid and one aphid have mitochondrial genomes with a gene order very similar to that of the proposed insect ancestor. The remaining four species of whiteflies had variations in the gene order. In all cases, there was the excision of a DNA fragment encoding for cytochrome oxidase subunit III(COIII-tRNAgly-NADH dehydrogenase subunit 3(ND3-tRNAala-tRNAarg-tRNAasn from the ancestral position between genes for ATP synthase subunit 6 and NADH dehydrogenase subunit 5. Based on the position in which all or part of this fragment was inserted, the mitochondria could be subdivided into four different gene arrangement types. PCR amplification spanning from COIII to genes outside the inserted region and sequence determination of the resulting fragments, indicated that different whitefly species could be placed into one of these arrangement types. A phylogenetic analysis of 19 whitefly species based on genes for mitochondrial cytochrome b, NADH dehydrogenase subunit 1, and 16S ribosomal DNA as well as cospeciating endosymbiont 16S and 23S ribosomal DNA indicated a clustering of species that corresponded to the gene arrangement types. Conclusions In whiteflies, the region of the

  12. The GC-MS analysis of volatile oil from Atractylodes Macrocephala Koidz,Pericarpium Citri Reticulate and their mixed samples%药对白术-陈皮挥发油成分GC-MS分析

    Institute of Scientific and Technical Information of China (English)

    杨小红; 罗琼; 胡剑卓; 陈文; 谭敏

    2012-01-01

    Objective To analysis the volatile components in herbal pair Atractylodes Macrocephala -Pericarpium Citri Reticulatae (HP AM-PCR), single herb Atractylodes Macrocephala(AM) and Pericarpium Citri Reticulatae (PCR) quantitatively. Methods Volatile oil from above materials were obtained with water reflux condensation method;oil composition was detected by gas - mass spectrometry (GC-MS) and the data was analyzed with heuristic evolving latent projection (HELP); Comparing the difference between chromatographys to identify the main chemical constituents. Results There was no new compound found in herbal pair. The compounds were from single herbs. Conclusion Chemical changes in herbal pair AM -PCR were physical compatibility.%目的:定性、定量分析药对白术-陈皮、单味药白术和陈皮的主要挥发油成分,探讨药对和单味药挥发油成分变化.方法:共水回流冷凝法分别提取单味白术、陈皮及药对挥发油、气相-质谱(GC-MS)检测,直观推导式演进特征投影(HEIP)法解析所得GC-MS数据,比较图谱差异,鉴别主要化学成分.结果:药对白术-陈皮主要组分中未发现新的结构类型化合物,挥发油化合物来源于单味药材,且主要为白术挥发油.结论:药对白术-陈皮挥发油化学成分变化属于物理配伍变化.

  13. A two-in-one superhydrophobic and anti-reflective nanodevice in the grey cicada Cicada orni (Hemiptera)

    Energy Technology Data Exchange (ETDEWEB)

    Dellieu, Louis, E-mail: louis.dellieu@unamur.be; Sarrazin, Michaël, E-mail: michael.sarrazin@unamur.be; Simonis, Priscilla; Deparis, Olivier; Vigneron, Jean Pol [Research Center in Physics of Matter and Radiation (PMR), Department of Physics, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur (Belgium)

    2014-07-14

    Two separated levels of functionality are identified in the nanostructure which covers the wings of the grey cicada Cicada orni (Hemiptera). The upper level is responsible for superhydrophobic character of the wing, while the lower level enhances its anti-reflective behavior. Extensive wetting experiments with various chemical species and optical measurements were performed in order to assess the bi-functionality. Scanning electron microscopy imaging was used to identify the nanostructure morphology. Numerical optical simulations and analytical wetting models were used to prove the roles of both levels of the nanostructure. In addition, the complex refractive index of the chitinous material of the wing was determined from measurements.

  14. First Report of Citrus Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae in the State of Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Rúbia de Oliveira Molina

    2014-08-01

    Full Text Available The citrus blackfly Aleroucanthus woglumi Ashby, (Hemiptera Aleyrodidae is an important pest that occurs in citrus groves, native to south-east Asia. In Brazil, according to the Ministry of Agriculture, this is a quarantine pest (A2 under official control IN 52, 2007 (MAPA and is not widespread in the country. The insect can infest more than 300 host plants, including cultivated plants, ornamentals and weeds, but mostly occurs in the plants of the genus citrus. This paper is the first report of citrus blackfly in the State of Paraná.

  15. A new Anagyrus (Hymenoptera: Encyrtidae) from Argentina, parasitoid of Hypogeococcus sp. (Hemiptera: Pseudococcidae) on Harrisia pomanensis (Cactaceae).

    Science.gov (United States)

    Triapitsyn, Serguei V; Aguirre, María B; Logarzo, Guillermo A

    2016-05-26

    A new species of Anagyrus Howard (Hymenoptera: Encyrtidae), A. lapachosus sp. n., is described from Salta Province of Argentina as a parasitoid of Hypogeococcus sp. (Hemiptera: Pseudococcidae) on Harrisia pomanensis cactus (Cactaceae). It is a candidate "new association" biological control agent for quarantine evaluation and possible following introduction to Puerto Rico (USA) against another Hypogeococcus sp., commonly called the Harrisia cactus mealybug and often misidentified as H. pungens Granara de Willink (according to our unpublished data the latter attacks only Amaranthaceae), which devastates or threatens the native cacti there and also in some other Caribbean islands (Triapitsyn, Aguirre et al. 2014; Carrera-Martínez et al. 2015).

  16. [Triatoma delpontei Romaña & Abalos, 1947 (Hemiptera, Tratominae) in the Brazilian State of Rio Grande do Sul].

    Science.gov (United States)

    Salvatella Agrelo, R; Basmadjian, Y; Rosa, R; Puime, A

    1993-01-01

    Triatoma delpontei (Romaña & Abalos, 1947) (Hemiptera, Triatominae) is an ornithophilic sylvatic with a particular association to the psittacid Myiopsitta monachus (Boaddert, 1783). It is found in the continental biogeographical province of the Chaco, where it inhabits the nests or M. monachus, in subtropical xerophytic forests. The authors report the first finding of T. delpontei in Brasil, in the "campanha" region of the State or Rio Grande do Sul (Barra do Quarai, Uruguaiana), on the right bank of the River Cuareim, not far from de Uruguayan border.

  17. Hallazgo de Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae) en el estado brasileño de "Rio Grande do Sul"

    OpenAIRE

    Salvatella,Roberto; Basmadjián,Yester; Rosa,Raquel; Martínez, María; Mendaro,Gabriela; Civila,Eduardo

    1991-01-01

    Triatoma platensis Neiva 1913 (Hemiptera, Triatominae), especie ornitófila, con área de dispersión conocida en Argentina, Bolivia, Paraguay y Uruguay es notificada en un primer registro para Brasil. Hallada en el municipio de Uruguaiana (Río Grande do Sul) en nidos de Anumbius annumbi (Vieillot, 1817) (Passeriformes, Furnariidae) donde cohabitaba con cricétidos de la especie Orizomys flavescens. Ningún ejemplar de los siete colectados se presentó infectado por Trypanosoma cruzi.

  18. Mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) attacking Hibiscus rosa-sinensis L. in Malaysia, with two new country records

    Science.gov (United States)

    Sartiami, Dewi; Watson, Gillian W.; Mohamad Roff, M. N.; Idris, A. B.

    2016-11-01

    A survey of mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) attacking the national flower of Malaysia, Hibiscus rosa-sisnensis L. and Hibiscus spp. (Malvaceae) was conducted in Selangor and Kuala Lumpur, Malaysia, from January to March 2016. Adult females were mounted on microscope slides in Canada balsam. The five species identified were Ferrisia dasylirii (Cockerell), Maconellicoccus hirsutus (Green), Paracoccus marginatus Williams and Granara de Willink, Phenacoccus solenopsis (Tinsley) and Pseudococcus jackbeardsleyi Gimpel & Miller. Two of these, the invasive species Ferrisia dasylirii and P. solenopsis were introduced and first recorded in Malaysia.

  19. An annotated checklist of the scale insects of Iran (Hemiptera, Sternorrhyncha, Coccoidea with new records and distribution data

    Directory of Open Access Journals (Sweden)

    Masumeh Moghaddam

    2013-09-01

    Full Text Available A list of scale insects (Hemiptera: Sternorrhyncha: Coccoidea of Iran is present based mainly on the literature records since 1902. In total, 13 families and 275 species have been recorded and these are listed along with their locality data and host plants. The families are as follows: Asterolecaniidae, Cerococcidae, Coccidae, Diaspididae, Eriococcidae, Kermesidae, Margarodidae, Monophlebidae, Ortheziidae, Phoenicococcidae, Pseudococcidae, Putoidae and Rhizoecidae. The following ten species are recorded for the first time from Iran: Diaspidiotus lenticularis (Lindinger, D. wuenni (Lindinger, Fiorinia proboscidaria Green, Koroneaspis lonicerae Borchsenius, Eriococcus cingulatus Kiritchenko, E. pamiricus (Bazarov, E. reynei Schmutterer, E. sanguinairensis Goux and E. saxidesertus (Borchsenius and Porphyrophora victoriae Jashenko.

  20. An annotated checklist of the scale insects of Iran (Hemiptera, Sternorrhyncha, Coccoidea) with new records and distribution data.

    Science.gov (United States)

    Moghaddam, Masumeh

    2013-01-01

    A list of scale insects (Hemiptera: Sternorrhyncha: Coccoidea) of Iran is present based mainly on the literature records since 1902. In total, 13 families and 275 species have been recorded and these are listed along with their locality data and host plants. The families are as follows: Asterolecaniidae, Cerococcidae, Coccidae, Diaspididae, Eriococcidae, Kermesidae, Margarodidae, Monophlebidae, Ortheziidae, Phoenicococcidae, Pseudococcidae, Putoidae and Rhizoecidae. The following ten species are recorded for the first time from Iran: Diaspidiotus lenticularis (Lindinger), Diaspidiotus wuenni (Lindinger), Fiorinia proboscidaria Green, Koroneaspis lonicerae Borchsenius, Eriococcus cingulatus Kiritchenko, Eriococcus pamiricus (Bazarov), Eriococcus reynei Schmutterer, Eriococcus sanguinairensis Goux and Eriococcus saxidesertus (Borchsenius) and Porphyrophora victoriae Jashenko.

  1. Description of a new soft scale insect of the genus Pulvinaria Targioni Tozzetti (Hemiptera, Coccoidea, Coccidae) from Bogota, Colombia.

    Science.gov (United States)

    Tanaka, Hirotaka; Kondo, Takumasa

    2015-01-01

    A new soft scale (Hemiptera: Coccoidea: Coccidae) species, Pulvinariacaballeroramosae Tanaka & Kondo, sp. n., is described from specimens collected on twigs of Ficussoatensis Dugand (Moraceae) in Bogota, Colombia. The new species resembles Pulvinariadrymiswinteri Kondo & Gullan, described from Chile on Drimyswinteri J.R. Forst. & G. Forst. (Winteraceae), but differs in the distribution of preopercular pores on the dorsum, the presence of dorsal tubular ducts, dorsal microducts, and reticulation on the anal plates; and in its feeding habits, i.e., Pulvinariacaballeroramosae feeds on the twigs whereas Pulvinariadrymiswinteri feeds on the leaves of its host. A key to the Colombian species of Pulvinaria Targioni Tozzetti is provided.

  2. Three new species of Baeoentedon Girault (Hymenoptera: Eulophidae) from China, with the first record of whitefly host association (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Wang, Zhu-Hong; Huang, Jian; Polaszek, Andrew

    2014-07-01

    Three new species of Baeoentedon Girault (Hymenoptera: Eulophidae) are described from China, Baeoentedon balios Wang, Huang & Polaszek sp. nov., Baeoentedon bouceki Wang, Huang & Polaszek sp. nov. and Baeoentedon virgatus Wang, Huang & Polaszek sp. nov. Both female and male of Baeoentedon balios were reared from the whitefly Pealius spina (Singh) (Hemiptera: Aleyrodidae) on the bodhi tree Ficus religiosa L. (Urticales: Moraceae). The male and the whitefly host association of Baeoentedon are recorded for the first time. A key is also provided to females of the world species of the genus.

  3. Sampling Methods for Detection and Monitoring of the Asian Citrus Psyllid (Hemiptera: Psyllidae).

    Science.gov (United States)

    Monzo, C; Arevalo, H A; Jones, M M; Vanaclocha, P; Croxton, S D; Qureshi, J A; Stansly, P A

    2015-06-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama is a key pest of citrus due to its role as vector of citrus greening disease or "huanglongbing." ACP monitoring is considered an indispensable tool for management of vector and disease. In the present study, datasets collected between 2009 and 2013 from 245 citrus blocks were used to evaluate precision, sensitivity for detection, and efficiency of five sampling methods. The number of samples needed to reach a 0.25 standard error-mean ratio was estimated using Taylor's power law and used to compare precision among sampling methods. Comparison of detection sensitivity and time expenditure (cost) between stem-tap and other sampling methodologies conducted consecutively at the same location were also assessed. Stem-tap sampling was the most efficient sampling method when ACP densities were moderate to high and served as the basis for comparison with all other methods. Protocols that grouped trees near randomly selected locations across the block were more efficient than sampling trees at random across the block. Sweep net sampling was similar to stem-taps in number of captures per sampled unit, but less precise at any ACP density. Yellow sticky traps were 14 times more sensitive than stem-taps but much more time consuming and thus less efficient except at very low population densities. Visual sampling was efficient for detecting and monitoring ACP at low densities. Suction sampling was time consuming and taxing but the most sensitive of all methods for detection of sparse populations. This information can be used to optimize ACP monitoring efforts.

  4. Feeding preference ofNezara viridula (Hemiptera: Pentatomidae and attractiveness of soybean genotypes

    Directory of Open Access Journals (Sweden)

    Efrain de Santana Souza

    2013-12-01

    Full Text Available Nezara viridula (L. (Hemiptera: Pentatomidae is a cosmopolitan insect that causes economic damages to several cultures, in particular soybeans (Glycine max [L.] Merr. Among the techniques that involve Integrated Pest Management, the resistance of plants is pointed as a tool of great value and can contribute to the reduction of populations of insects. The feeding preferences of adults of southern green stink bug (N. viridula, and the attractiveness of soybean genotypes were evaluated under laboratory conditions to detect the most resistant material against attack from this insect. A choice test, using mature grains and green pods of the genotypes was carried out, in which the number of individuals attracted in different periods was counted. Feeding preference was evaluated in the choice tests using green pods and the number of pricks and the average time spent feeding by pricks were evaluated. In addition, texture and trichome density in the green pods were evaluated. The mature grains of 'TMG 117RR' and 'TMG 121RR' were less attractive to the adults of N. viridula. Regarding the green pods, 'IAC 17' and PI 227687 were less attractive; 'IAC 17' and 'IAC PL1' were less consumed, indicating the feeding non-preference as a resistance mechanism. 'IAC 17', 'TMG-117RR' and PI 227687 presented high levels of trichome density, and in 'IAC 17' this morphological characteristic was considered to be the main resistance factor against N. viridula. These results may be useful for breeding programs that focus on the resistance of soybeans to insects.

  5. Ecology and Management of Kudzu Bug (Hemiptera: Plataspidae) in Southeastern Soybeans

    Science.gov (United States)

    Lahiri, Sriyanka

    2016-01-01

    Kudzu bug, Megacopta cribraria Fabricius (Hemiptera: Plataspidae), is an invasive exotic pest of soybeans that has been present in the southeastern United States since 2009 and has been rapidly spreading through soybean-producing states. Their primary reproductive hosts in the United States are soybean, kudzu, pigeon pea, black eye pea, lima bean, pinto bean, wisteria, white sweet clover, white clover, red clover, alfalfa, perennial peanut, and American joint vetch. In soybeans, the kudzu bug feeds on vascular fluids at the stem, petiole, and nodes, causing yield losses of up to 60%. The current management recommendation for this pest includes spraying of pyrethroids such as bifenthrin, but this method is not environmentally friendly, as this negatively impacts beneficial insect populations. Sustainable management tactics, including the development of economic thresholds for insecticide sprays, assessing the spatial and temporal distribution of this pest, manipulating cultivation practices, use of biological control, and host plant resistance, are currently being explored. We present an overview of the ecology of the kudzu bug in soybeans and available management tactics to assist with the management of this potentially devastating pest of soybeans as it spreads westward.

  6. First record of Triatoma maculata (Erichson, 1848 (Hemiptera: Reduviidae: Triatomini in Riohacha, La Guajira – Colombia

    Directory of Open Access Journals (Sweden)

    Edith Natalia Gómez-Melendro

    2014-11-01

    Full Text Available Introduction. Knowledge of vector insect species, their habitat and geographical distribution is crucial for determining the risk of transmission of the etiologic agents that cause disease in humans, which allows defining strategies for prevention, surveillance and control in line with the characteristics of each area. Objective. To determine the presence and public health importance of vectors of Chagas disease in the indigenous settlements of Marbacella and El Horno of the Wayúu ethnic group in the municipality of Riohacha, La Guajira, Colombia. Materials and methods. From active search, installation and inspection of biosensors and occasional catches, Hemiptera: Reduviidae: Triatomini were collected intra and in the peridomicile housing of the indigenous settlements of El Horno and Marbacella of the the Wayúu ethnic group. Indices of intra and peridomestic infestation, colonization, density, dispersion and natural infection with Trypanosoma cruzi Chagas, 1909 were calculated. Results. 79.6% (n = 90 of the specimens were collected around the homes and 20.3% (n = 23 inside the homes, all corresponding to Triatoma maculata (Erichson, 1848. The natural infection indices with T. cruzi accounted for 43.5% for Marbacella and 36% for El Horno. Conclusion. This is the first reported capture of individuals of T. maculata, considered a secondary vector of Chagas disease in Colombia, naturally infected with T. cruzi in the municipality of Riohacha expanding the geographical distribution of the species in the department of La Guajira.

  7. Molecular characterization and gene functional analysis of Dicer-2 gene from Nilaparvata lugens(Hemiptera:Geometroidea)

    Institute of Scientific and Technical Information of China (English)

    Xiao-Yi Zhang; Kai Lu; Jia-Liang Zhou; Qiang Zhou

    2013-01-01

    Nilaparvata lugens(St((A)l)(Hemiptera: Geometroidea),a serious rice pest in many countries of Asia,causes a great loss in rice production every year.RNA interference (RNAi)is a powerful technology for gene function study in insects and a potential tool for pest control.As a core component of RNAi pathway,Dicer-2(Dcr-2)protein determines the production of small interfering RNA(siRNA)and is crucial for the efficiency of RNAi.In this study,the full-length complementary DNA(cDNA)ofN.lugens Dcr-2(NlDcr-2)was first cloned and analyzed,and then the RNAi experiment was conducted to explore the function of NIDcr-2 gene.The complete Dcr-2 cDNA ofN.lugens was 4971 bp in length with an open reading frame(ORF)of 1,656 amino acids.Phylogenetic and protein domain analysis showed that the predicted NlDcr-2 protein was similar to Tribolium castaneum.In the RNAi experiment,the messenger RNA level of NIDcr-2 was significantly reduced by NlDcr-2double-stranded RNA(dsRNA)(dsDcr-2).Fifty-five per cent decrease of NlDcr-2 was found after 4 days of unremitting feeding.No significant effect was observed on the development ofN.lugens after dsRNA ingestion.

  8. Inter- and intraspecific variation in defensive compounds produced by five neotropical stink bug species (Hemiptera: Pentatomidae).

    Science.gov (United States)

    Pareja, Martín; Borges, Miguel; Laumann, Raúl A; Moraes, Maria C B

    2007-07-01

    The differences in composition of defensive secretions between nymphs, adult males and adult females of Chinavia impicticornis (=Acrosternum impicticorne), Chinavia ubica (=Acrosternum ubicum), Euschistus heros, Dichelops melacanthus and Piezodorus guildinii (Hemiptera, Pentatomidae) were analysed within and between species using compositional log-ratio statistics and canonical variates analysis. Differences in composition between nymphs, males and females were found for all species, as well as when all species were pooled. In particular, tetradecanal appears to be a predominantly nymphal compound in D. melacanthus, E. heros and P. guildinii. In the two Chinavia species 4-oxo-(E)-2-hexenal and an unknown compound were more dominant in nymphs. The interspecific analysis revealed a good separation of defensive compounds according to their taxonomic relationship. Thus, the two Chinavia species grouped together, with (E)-2-decenal and (E)-2-hexenyl acetate, contributing to this separation. The other three species also differed from each other, with (E)-2-octenal associated to D. melacanthus, (E)-2-hexenal to P. guildinii and (E,E)-2,4-decadienal and tetradecanal to E. heros. The pooled analysis of stage ignoring species revealed tetradecanal and 4-oxo-(E)-2-decenal (tentative identification) strongly associated to nymphs. Thus, there are predictable differences between stages, and many of the differences are conserved between species. Consideration of these differences could prove to be important in understanding stink bug-natural enemy interactions, and in optimising biocontrol efforts.

  9. Anagrus turpanicus sp. n. (Hymenoptera: Mymaridae) from China, an egg parasitoid of Arboridia kakogowana (Hemiptera: Cicadellidae).

    Science.gov (United States)

    Hu, Hong-Ying; Triapitsyn, Serguei V

    2016-01-01

    A new Palaearctic species of Anagrus Haliday (Hymenoptera: Mymaridae), A. turpanicus Triapitsyn & Hu sp. n., is described and illustrated from Xinjiang Uyghur Autonomous Region of China. It was reared from parasitized eggs of the leafhopper Arboridia kakogowana (Matsumura) (Hemiptera: Cicadellidae) (Fig. 10) on cultivated table grapes from Turpan, which had been previously misidentified there as Erythroneura apicalis (Nawa) (e.g., Wang et al. 2004, 2011; Luan et al. 2006). This leafhopper has been an important economic pest in Turpan area since 1998, causing serious damage to the cultivated grapevines (Wang et al. 2004; Luan et al. 2006). Wang et al. (2011) reported that the mite Leptus sp. (Erythraeidae) and several unidentified spider species were the main natural enemies of Erythroneura apicalis in and around Turpan. This is the first record of A. kakogowana from China; it was not included in the key to the Chinese species of the genus Arboridia Zachvatkin by Song & Li (2015). Arboridia kakogowana is native to the eastern Palaearctic region (Japan, Korea, and Far East of Russia), and has been recently recorded as an invasive pest of cultivated grapes in southern Russia (Gnezdilov et al. 2008).

  10. Relative Infestation Level and Sensitivity of Grapevine Cultivars to the Leafhopper Empoasca vitis (Hemiptera: Cicadellidae).

    Science.gov (United States)

    Fornasiero, D; Pavan, F; Pozzebon, A; Picotti, P; Duso, C

    2016-02-01

    The leafhopper Empoasca vitis (Göthe) (Hemiptera: Cicadellidae) feeds on veins of grapevine leaves, mainly on the phloem, causing physiological injury, color change and drying of leaf margins, yield and sugar content reduction. The relative infestation level (i.e., the probability that a plant is attacked by herbivores) of E. vitis on different grapevine cultivars and their sensitivity (i.e., the incidence of symptoms expression in response to herbivore feeding or other stimuli) to this pest were studied over four years in two vineyards located in northeastern Italy. Some cultivars (e.g., Carménère and Sauvignon Blanc) were usually more infested than others (e.g., Cabernet Sauvignon and Pinot Gris), although some differences were observed among years and sites. The sensitivity varied among cultivars, i.e., some of them showed more symptoms than expected on the basis of infestation levels (e.g., Carménère and Merlot), in contrast with others (e.g., Rhine Riesling and Chardonnay). Information obtained can be used within the framework of integrated pest management in vineyards. Action thresholds should differ on the basis of sensitivity. Sampling must first be carried out on the most susceptible cultivar and, if the action threshold is exceeded, it should be extended to the remaining cultivars based on their decreasing relative infestation level.

  11. Evaluation of digital photography for quantifying Cryptococcus fagisuga (Hemiptera: Eriococcidae) density on American beech trees.

    Science.gov (United States)

    Wieferich, D J; Hayes, D B; McCullough, D G

    2013-06-01

    Beech scale (Cryptococcus fagisuga Lindinger) (Hemiptera: Eriococcidae) is an invasive forest insect established in the eastern United States and Canada. It predisposes American beech (Fagus grandifolia Ehrhart) trees to infection by Neonectria spp. Fungi causing beech bark disease. White wax secreted by the diminutive scales obscures individual insects, making it difficult to accurately quantify beech scale density. Our goals were to 1) evaluate the relationship between the area of wax and number of beech scales on bark samples, 2) determine whether digital photos of bark could accurately quantify beech scale density, and 3) compare efficiency and utility of a qualitative visual estimate and using the quantitative digital photo technique to assess beech scale populations. We visually estimated beech scale abundance and photographed designated areas on the trunk of 427 trees in 40 sites across Michigan. Photos were analyzed using a binary threshold technique to quantify the area of beech scale wax on each photo. We also photographed and then collected 104 bark samples from 45 additional beech trees in ten sites. We removed the wax, counted individual scales on each sample using a microscope, and assessed the linear relationship between wax area and scale counts. Area of wax explained approximately 80% of the variability in scale density. We could typically quantify beech scale density on 15 photographs per hour. Qualitative visual assessments of beech scale in the field corresponded with estimates derived from photos of bark samples for 79% of trees.

  12. Probing behaviors of Sitobion avenae (Hemiptera: Aphididae on enhanced UV-B irradiated plants

    Directory of Open Access Journals (Sweden)

    Hu Zu-Qing

    2013-01-01

    Full Text Available UV-B induced changes in plants can influence sap-feeding insects through mechanisms that have not been studied. Herein the grain aphid, Sitobion avenae (Fabricius (Hemiptera: Aphididae, was monitored on barley plants under the treatments of control [0 kJ/ (m2.d], ambient UV-B [60 kJ/ (m2.d], and enhanced UV-B [120 kJ/ (m2.d] irradiation. Electrical penetration graph (EPG techniques were used to record aphid probing behaviors. Enhanced UV-B irradiated plants negatively affected probing behaviors of S. avenae compared with control plants. In particular, phloem factors that could diminish sieve element acceptance appeared to be involved, as reflected by smaller number of phloem phase, shorter phloem ingestion, and fewer aphids reaching the sustained phloem ingestion phase (E2>10min. On the other hand, factors from leaf surface, epidermis, and mesophyll cannot be excluded, as reflected by higher number of non-probing, longer non-probing and pathway phase, and later the time to first probe.

  13. Genetic variability of Triatoma flavida and Triatoma bruneri (Hemiptera: Reduviidae by RAPD-PCR technique

    Directory of Open Access Journals (Sweden)

    Jorge Fraga

    2011-02-01

    Full Text Available The Triatominae (Hemiptera:Reduviidae contains the principal and potential Chagas disease vectors present in Mexico, Central America and South America. Triatoma flavida and T. bruneri are Cuban species. These species are closely related according to morphology and were considered synonyms until 1981, when they were separated on the grounds of external characters of the body and the morphology of male genitalia. The present study seeks to analyze genetic polymorphism of T. flavida and T. bruneri populations using RAPD techniques, and to assess the genetic relationship between these species. Ten random primers were used to evaluate the genetic variability among species using RAPD-PCR. The genetic flow among them was calculated. The dendrogram based on calculated Jaccard distances showed two clearly distinguishable clusters which coincided with the studied species. Within each species, moderate genetic differentiation (Fst 0.05-0.15 and migration rates (N > 1 were found among populations, that reveal gene flow and genetic homogeneity. Between species, the Fst value showed a high genetic differentiation and the migration rate was insufficient to maintain genetic homogeneity, and confirmed the absence of gene flow between them. Our results confirm the genetic variability among T. flavida and T. bruneri species.

  14. Genetic variability of Triatoma flavida and Triatoma bruneri (Hemiptera: Reduviidae) by RAPD-PCR technique.

    Science.gov (United States)

    Fraga, Jorge; Rodriguez, Jinnay; Fuentes, Omar; Hernández, Yenin; Castex, Mayda; Gonzalez, Raul; Fernández-Calienes, Aymé

    2011-01-01

    The Triatominae (Hemiptera:Reduviidae) contains the principal and potential Chagas disease vectors present in Mexico, Central America and South America. Triatoma flavida and T. bruneri are Cuban species. These species are closely related according to morphology and were considered synonyms until 1981, when they were separated on the grounds of external characters of the body and the morphology of male genitalia. The present study seeks to analyze genetic polymorphism of T. flavida and T. bruneri populations using RAPD techniques, and to assess the genetic relationship between these species. Ten random primers were used to evaluate the genetic variability among species using RAPD-PCR. The genetic flow among them was calculated. The dendrogram based on calculated Jaccard distances showed two clearly distinguishable clusters which coincided with the studied species. Within each species, moderate genetic differentiation (Fst 0.05-0.15) and migration rates (N > 1) were found among populations, that reveal gene flow and genetic homogeneity. Between species, the Fst value showed a high genetic differentiation and the migration rate was insufficient to maintain genetic homogeneity, and confirmed the absence of gene flow between them. Our results confirm the genetic variability among T. flavida and T. bruneri species.

  15. The genus Lycoderides Sakakibara, stat. nov., its composition and descriptions of new species (Hemiptera, Membracidae, Stegaspidinae

    Directory of Open Access Journals (Sweden)

    Albino M. Sakakibara

    2013-09-01

    Full Text Available The genus Lycoderides Sakakibara, stat. nov. , its composition and descriptions of new species (Hemiptera, Membracidae, Stegaspidinae.The subgenus Lycoderes (Lycoderides Sakakibara, 1972 is raised to the genus category - Lycoderides stat. nov.. - : and it now includes: Lycoderides amazonicus (Sakakibara, 1991, comb. nov. , Lycoderides brevilobus (Sakakibara, 1972, comb. nov. , Lycoderides burmeisteri (Fairmaire, 1846, comb. nov. , Lycoderides cultratus (Sakakibara, 1991, comb. nov. , Lycoderides fernandezi (Strümpel, 1988, comb. nov. , Lycoderides fuscus (Amyot & Serville, 1843, comb. nov. , Lycoderides gradatus (Sakakibara, 1972, comb. nov. , Lycoderides hippocampus (Fabricius, 1803, comb. nov. , Lycoderides luteus (Funkhouser, 1940, comb. nov. , Lycoderides marginalis (Walker, 1851, comb. nov. , Lycoderides nathanieli (Cryan, 1999, comb. nov. , Lycoderides obtusus (Sakakibara, 1991, comb. nov. , Lycoderides pennyi (Sakakibara, 1991, comb. nov. , Lycoderides phasianus (Fowler, 1896, comb. nov. (= Enchenopa minamen Buckton, 1901,SYN. NOV: , Lycoderides protensus (Sakakibara, 1991, comb. nov. , Lycoderides serraticornis (Fowler, 1896, comb. nov. , and Lycoderides strumpeli (Sakakibara, 1991, comb. nov. The following new species are described: Lycoderides abditus, sp. nov. , Lycoderides brulei,SP. NOV. (: both from French Guiana, Lycoderides capixaba, sp. nov. (from Brazil, Espírito Santo, Lycoderides cavichiolii, sp. nov. (from Brazil, Rio de Janeiro, Lycoderides meloi, sp. nov. (from Brazil, Bahia, and Lycoderides oliviae, sp. nov. (from Brazil, Minas Gerais. Other nomenclatural change: Stegaspis bracteata (Fabricius, 1787 = Lycoderes capitata Buckton, 1903, syn. nov. New records of geographical distribution and a key to the species are provided.

  16. Laboratory Evaluation of Different Insecticides against Hibiscus Mealybug, Maconellicoccus hirsutus (Hemiptera: Pseudococcidae

    Directory of Open Access Journals (Sweden)

    Samman Fatima

    2016-01-01

    Full Text Available Hibiscus mealybug, Maconellicoccus hirsutus (Hemiptera: Pseudococcidae, is the major pest of many vegetables, fruits, crops, and ornamental plants causing losses to the farmers and its control has been an issue of significance in the pest management. This study was aimed at evaluating different concentrations (0.06%, 0.1%, and 0.14% of Telsta, Advantage, Talstar, Imidacloprid, and their mixtures against hibiscus mealybug in the Laboratory of Systematics and Pest Management at University of Gujrat, Pakistan. The toxic effect was evaluated in the laboratory bioassay after 24 and 48 h of the application of insecticides. The highest mortality (95.83% was shown by Talstar and Talstar + Imidacloprid at the concentration of 0.14% after 48 h followed by Advantage + Talstar with 87.50% mortality at 0.14% concentration after 48 h of application. The study also showed that the least effective treatment observed was Advantage + Telsta with no mortality after 24 h and 25% mortality after 48 h at 0.14% concentration. The study revealed that the concentration 0.14% was highly effective in lowering the mealybug population and insecticide mixtures were effective in reducing mealybug density. The study emphasizes the use of such insecticide mixtures to develop better management strategy for mealybug populations attacking ornamental plants. However effects of such insecticide mixtures on other organisms and biological control agents should be checked under field conditions.

  17. Harmonic radar tagging for tracking movement of Nezara viridula (Hemiptera: Pentatomidae).

    Science.gov (United States)

    Pilkay, Grant L; Reay-Jones, Francis P F; Greene, Jeremy K

    2013-10-01

    Harmonic radar tagging was investigated as a method for monitoring the movement of the southern green stink bug, Nezara viridula (L.) (Hemiptera: Pentatomidae). Because adhesive toxicity and tag weight limit the use of this technology, initial efforts focused on selection of the optimal adhesive and design of harmonic radar tags to reduce impact on the movement of stink bugs. A design consisting of a 6-cm-long 0.10-mm-thick silver-plated copper monopole on the anode terminal of a three-contact Schottky barrier diode attached with Gorilla super glue provided a compromise between unimpaired movement and tracking range, adding an additional 8% to the weight of the stink bug while not significantly (P > 0.05) reducing walking or flying mobility in the laboratory. Recovery of tagged stink bugs in cotton, Gossypium hirsutum (L.), and fallow fields ranged from 10 to 75% after 24 h, whereas marked stink bugs were recovered at rates of 0-35% by using sweep net or drop cloth sampling. The distance dispersed in the field was not impacted (P > 0.05) by crop, tagged status, or gender of the insect. Future research should examine possible improvements to the harmonic radar transceiver and the wire antenna to decrease encumbrance.

  18. Effect of population structure and size on aggregation behavior of Cimex lectularius (Hemiptera: Cimicidae).

    Science.gov (United States)

    Pfiester, Margie; Koehler, Philip G; Pereira, Roberto M

    2009-09-01

    The bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), occurs in aggregations until the conditions are no longer beneficial, leading to dispersal. Active and passive bed bug dispersal causes migrations from main aggregations either within a room, from room to room within a building, or from building to building. Because bed bug movement is an important factor in the spread of infestations, we wanted to determine how population structure and size affect bed bug aggregations. Engorged bed bugs were placed in glass petri dish arenas at varying densities, sex ratios, and population compositions. Nymphs had a high tendency to aggregate, varying between 94 and 98%, and therefore were not the likely dispersal stage of the bed bug. At densities of 10 and 40 adults at a 1:1 sex ratio, there were significantly more lone females than lone males. When the population composition was varied, the percentage of lone females was significantly higher than that of males and nymphs at population compositions of 40 and 80% adults. When the sex ratio of adults was varied, there were significantly more lone females than males in arenas with 20, 50, and 80% males. Females, being found away from aggregations significantly more often than any other life stage, are potentially the dispersal stage of the bed bug. Active female dispersal away from main aggregations can potentially lead to treatment failures and should be taken into account when using control methods.

  19. Effects of fertilizer and low rates of imidacloprid on Adelges tsugae (Hemiptera: Adelgidae).

    Science.gov (United States)

    Joseph, S V; Hanula, J L; Braman, S K; Byrne, F J

    2011-06-01

    Healthy hemlock trees, Tsuga canadensis (L.) Carrière, and hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), populations should favor retention and population growth of adelgid predators such as Laricobius nigrinus Fender (Coleoptera: Derodontidae) and Sasajiscymnus tsugae (Sasaji & McClure) (Coleoptera: Coccinellidae). Eastern hemlock trees between 15 and 38 cm diameter at breast height (dbh) were treated with 0, 10, or 25% of 1.5 g imidacloprid (Merit 75 WP) per 2.5 cm dbh and were either fertilized or not, in a 3 by 2 factorial design. After 2 yr, imidacloprid reduced the numbers of ovisacs and eggs found on trees in a dosage-dependent manner, while enhancing tree growth parameters such as new shoots or needles and the length of new shoots. Fertilized trees had greater adelgid fecundity, which was positively correlated with total foliar N in both winter generations. In February 2009 (27 mo after imidacloprid treatment), higher imidacloprid dosages to unfertilized trees resulted in reduced adelgid fecundity. Concentrations of N, P, and K were higher in the foliage of trees treated with insecticide, whereas foliar aluminum concentrations were consistently lower in trees with higher insecticide dosages. Trees treated with low rates of imidacloprid were healthier than untreated trees, but only trees treated with the 0.1 x dosage had sufficient adelgids to possibly sustain predators over extended periods.

  20. Effects of gamma irradiation on different stages of mealybug Dysmicoccus neobrevipes (Hemiptera: Pseudococcidae)

    Energy Technology Data Exchange (ETDEWEB)

    The, Doan Thi, E-mail: doanthithe@yahoo.com [Research and Development Center for Radiation Technology, Vietnam Atomic Energy Institute, 202A Street 11, Linh Xuan Ward, Thu Duc District, Ho Chi Minh City (Viet Nam); Khanh, Nguyen Thuy; Lang, Vo Thi Kim; Van Chung, Cao [Research and Development Center for Radiation Technology, Vietnam Atomic Energy Institute, 202A Street 11, Linh Xuan Ward, Thu Duc District, Ho Chi Minh City (Viet Nam); An, Tran Thi Thien; Thi, Nguyen Hoang Hanh [Agriculture and Forestry University, Linh Trung Ward, Thu Duc District, Ho Chi Minh City (Viet Nam)

    2012-01-15

    Utilization of phytosanitary irradiation as a potential treatment to disinfest agricultural commodities in trade has expanded rapidly in the recent years. Cobalt-60 gamma ray target doses of 100, 150, 200 and 250 Gy were used to irradiate immatures and adults of Dysmicoccus neobrevipes (Beardsley) (Hemiptera: Pseudococcidae) infesting dragon fruits to find the most tolerant stage and the most optimal dose range for quarantine treatment. In general, irradiation affected significantly all life stages of D. neobrevipes mortality and adult reproduction. The pattern of tolerance to irradiation in D. neobrevipes was 1st instars<2nd instars<3rd instars Gamma Co-60 irradiation as a potential phytosanitary for quarantine treatments. > Reproduction ability of D. neobrevipes has been efficiently inhibited at low dose. > Pattern of tolerance to irradiation was 1st<2nd<3rd instars Doses from 200 to 250 Gy could be efficient to prevent the reproduction of mealybug.

  1. Biology and systematics of gall-inducing triozids (Hemiptera: Psylloidea) associated with Psidium spp. (Myrtaceae).

    Science.gov (United States)

    Carneiro, René G S; Burckhardt, Daniel; Isaias, Rosy M S

    2013-01-01

    Psidium myrtoides (Myrtaceae) shelters the gall inducer Nothotrioza myrtoidis gen. et sp. n. (Hemiptera: Psylloidea) which is described and illustrated here. Nothotrioza belongs to the family Triozidae and is probably most closely related to Neolithus, a monotypic Neotropical genus associated with Sapiun (Euphorbiaceae). Three species are recognized within Nothotrioza: the type species N. myrtoidis sp. n. associated with Psidium myrtoides, N. cattleiani sp. n. (misidentified by Butignol & Pedrosa-Macedo as Neotrioza tavaresi) with Psidium cattleianum, and N. tavaresi (Crawford) comb. n. (from Neotrioza) with an unidentified species of Malpighiaceae, respectively. A lectotype is designated here for Neotrioza tavaresi. Also, the diversity of insect galls associated with P. myrtoides and the biology of N. myrtoidis were examined. N. myrtoidis presents five instars and an annual life cycle synchronised with the phenology of P. myrtoides. Gall size was proportional to the insect developmental stages, and rates of parasitism and mortality were 15.7 % and 29.8 %, respectively. The red colour is an important macroscopic diagnostic feature of the gall that could be associated with parasite-free condition of the galling insect. The biological features presented by the system Psidium myrtoides--Nothotrioza myrtoidis are in accordance with other systems involving sucking galling insects, however, it is exceptional by its univoltine life cycle associated with a perennial plant in the Neotropics. The galls induced by the three known Nothotrioza spp. are morphologically similar, i.e. closed, globoid and unilocular, as well as the opening mechanism for releasing the adults.

  2. Taxonomic corrections to species of Rhyparochromidae (Hemiptera: Heteroptera) described by Carl Peter Thunberg.

    Science.gov (United States)

    Kondorosy, Előd; Rédei, Dávid; Mejlon, Hans

    2014-07-22

    Types of Rhyparochromidae (Hemiptera: Heteroptera: Lygaeoidea) species described by Carl Peter Thunberg, deposited in the Museum of Evolution (formerly Zoologiska Institut), Uppsala University, Uppsala, Sweden, were reexamined and the taxonomic and nomenclatural problems that existed among those species discussed and resolved as required. Lectotypes are designated for Cimex caffer Thunberg, 1784, Lygaeus ater Thunberg, 1822, Lygaeus biguttatus Thunberg, 1822, and Pendulinus guttatus Thunberg, 1825. The lectotype of Pendulinus (now Metochus) guttatus is designated as neotype of Pendulinus (now Metochus) uniguttatus Thunberg, 1822; as a result the former name becomes junior objective synonym of the latter. The following taxonomic changes are proposed: Lethaeus ater (Thunberg, 1822), new combination (from Lygaeus); Migdilybs biguttatus (Thunberg, 1822), new combination (from Lygaeus) = Migdilybs furcifer Hesse, 1925, new subjective synonym; Metochus uniguttatus (Thunberg, 1822) = Metochus bengalensis (Dallas, 1852), confirmed subjective synonym = Metochus yeh (Dohrn, 1860), confirmed subjective synonym; Raglius alboacuminatus (Goeze, 1778) = Cimex caffer Thunberg, 1874, confirmed subjective synonym. Lethaeus barberi Slater, 1964 does not belong to Lethaeus Dallas, 1852 but currently it cannot be placed with confidence in any existing genus. 

  3. Effects of selected fertilizers on the life history of Bemisia tabaci (Hemiptera: Aleyrodidae) biotype B.

    Science.gov (United States)

    England, K M; Sadof, C S; Cañnas, L A; Kuniyoshi, C H; Lopez, R G

    2011-04-01

    We tested the effects among a purportedly sustainable water-soluble fertilizer, a conventional water-soluble fertilizer, an alternation of these, a controlled-release fertilizer, and a clear water control on the life-history traits of sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae; =Bemisia argentifolii Bellows & Perring) biotype B reared on poinsettia (Euphorbia pulcherrima Willdenow ex Klotzch). Free amino acids in petioles were measured to estimate plant nutrient assimilation and phloem nutritional quality for B. tabaci biotype B. The sustainable fertilizer produced plants with the highest concentration of amino acids. In contrast, fecundity of whiteflies was lowest in plants treated with the sustainable fertilizer and the water control. The relationship between total amino acids in phloem and survival was significantly quadratic, with the highest survival at intermediate levels. Fecundity, however, was negatively correlated with total amino acid content of the maternal host plant. Variation in total amino acid concentration in petioles of plants treated within fertilizer treatments makes it difficult to predict whether a particular fertilizer will produce plants with enough amino acids to deleteriously affect both survivorship and fecundity and yet yield a plant of good quality. Despite this limitation, we can conclude that the use of this sustainable fertilizer will not cause increases in whitefly populations relative to plants fertilized with water-soluble and slow-release fertilizers that deliver the same level of nitrogen to the plant.

  4. Dose-response relationships of clothianidin, imidacloprid, and thiamethoxam to Blissus occiduus (Hemiptera: Blissidae).

    Science.gov (United States)

    Stamm, M D; Baxendale, F P; Heng-Moss, T M; Siegfried, B D; Blankenship, E E; Gaussoin, R E

    2011-02-01

    The western chinch bug, Blissus occiduus Barber (Hemiptera: Blissidae), has emerged as a serious pest of buffalograss, Buchlod dactyloides (Nuttall) Engelmann. In general, neonicotinoid insecticides effectively control a variety of turfgrass insects, particularly phloem-feeding pests. However, because of well documented inconsistencies in control, these compounds are generally not recommended for chinch bugs. This study was designed to document the contact and systemic toxicity of three neonicotinoid insecticides (clothianidin, imidacloprid, and thiamethoxam) to B. occiduus. In contact bioassays, thiamethoxam was approximately 20-fold less toxic than clothianidin or imidacloprid to B. occiduus nymphs and three-fold more toxic to adults. In adult systemic bioassays, thiamethoxam was up to five-fold more toxic than clothianidin or imidacloprid. Interestingly, thiamethoxam was significantly more toxic to adults than to nymphs in both contact and systemic bioassays. This was not observed with clothianidin or imidacloprid. Bifenthrin, used for comparative purposes, exhibited 1844-fold and 122-fold increase in toxicity to nymphs and adults, respectively. These results provide the first documentation of the relative toxicity of these neonicotinoid insecticides to B. occiduus.

  5. Susceptibility of twolined spittlebug (Hemiptera: Cercopidae) life stages to entomophagous arthropods in turfgrass.

    Science.gov (United States)

    Nachappa, Punya; Guillebeau, L P; Braman, S K; All, J N

    2006-10-01

    Prosapia bicincta (Say) (Hemiptera: Cercopidae), the twolined spittlebug, is an economic pest of turfgrass in the southeastern United States. No data concerning natural enemies of P. bicincta in turfgrass have been reported previously. We compared predation of spittlebug eggs, nymphs, and adults in the laboratory by potential generalist predators commonly found in turfgrass: bigeyed bugs Geocoris uliginosus Say and Geocoris punctipes Say; red imported fire ant, Solenopsis invicta Buren; wolf spiders (Lycosa sp. Walckenaer); carabid beetles Harpalaus pensylvanicus DeGeer and Calosoma sayi Dejean; and tiger beetles Megacephala carolina carolina L. Eggs were readily consumed by generalist predators. S. invicta consumed 100% of the eggs offered. H. pensylvanicus and C. sayi were also significant predators of P. bicincta eggs. Nymphs live in spittlemasses that protect them from attack by predators, but exposed nymphs were susceptible to attack when mechanically removed from their spittlemasses. S. invicta and M. carolina carolina caused significant mortality of exposed nymphs. P. bicincta adults are aposematic and have the ability to reflex bleed; however, reflex bleeding did not prevent attack by predators. S. invicta and M. carolina carolina killed 100% of the adult spittlebugs offered in laboratory bioassays. Lycosa sp. are less voracious predators of adults. Sound background knowledge about P. bicincta and its potential natural enemy complex is important for the development and implementation of a detailed, site-specific, biologically based pest management program in turfgrass.

  6. Biotypic diversity in greenbug (Hemiptera: Aphididae): microsatellite-based regional divergence and host-adapted differentiation.

    Science.gov (United States)

    Weng, Yiqun; Perumal, Azhaguvel; Burd, John D; Rudd, Jackie C

    2010-08-01

    Nineteen isolates of the cereal aphid pest greenbug, Schizaphis graminum (Rondani) (Hemiptera: Aphididae), were collected from wheat, Triticum aestivum L.; barley, Hordeum vulgare L.; or noncultivated grass hosts in five locations from Colorado and Wyoming. Parthenogenetic colonies were established. Biotypic profiles of the 19 isolates were determined based on their abilities to damage a set of host plant differentials, and 13 new biotypes were identified. Genetic diversity among the 19 isolates and five previously designated greenbug biotypes (E, G, H, I, and K) was examined with 31 cross-species transferable microsatellite (simple sequence repeat) markers. Neighbor-joining clustering analysis of marker data revealed host-adapted genetic divergence as well as regional differentiation of greenbug populations. Host associated biotypic variation seems to be more obvious in "agricultural biotypes," whereas isolates collected from noncultivated grasses tend to show more geographic divergence. It seems that the biotype sharing the most similar biotypic profiles and the same geographic region with current prevailing one may have the greatest potential to become the new prevailing biotype. Close monitoring of greenbug population dynamics especially biotypic variation on both crop plants and noncultivated grasses in small grain production areas may be a useful strategy for detecting potentially new prevailing virulent biotypes of the greenbug.

  7. Seasonal phenology, spatial distribution, and sampling plan for the invasive mealybug Phenacoccus peruvianus (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Beltrá, A; Garcia-Marí, F; Soto, A

    2013-06-01

    Phlenacoccus peruvianus Granara de Willink (Hemiptera: Pseudococcidae) is an invasive mealybug of Neotropical origin. In recent years it has invaded the Mediterranean Basin causing significant damages in bougainvillea and other ornamental plants. This article examines its phenology, location on the plant and spatial distribution, and presents a sampling plan to determine P. peruvianus population density for the management of this mealybug in southern Europe. Six urban green spaces with bougainvillea plants were periodically surveyed between March 2008 and September 2010 in eastern Spain, sampling bracts, leaves, and twigs. Our results show that P. peruvianus abundance was high in spring and summer, declining to almost undetectable levels in autumn and winter. The mealybugs showed a preference for settling on bracts and there were no significant migrations between plant organs. P. peruvianus showed a highly aggregated distribution on bracts, leaves, and twigs. We recommend abinomial sampling of 200 leaves and an action threshold of 55% infested leaves for integrated pest management purposes on urban landscapes and enumerative sampling for ornamental nursery management and additional biological studies.

  8. Molecular Characterization and Expression Profiles of Polygalacturonase Genes in Apolygus lucorum (Hemiptera: Miridae.

    Directory of Open Access Journals (Sweden)

    Lili Zhang

    Full Text Available Polygalacturonase (PG is an enzyme in the salivary glands of piercing-sucking mirid bugs (Hemiptera: Miridae that plays a key role in plant feeding and injury. By constructing a full-length cDNA library, we cloned and characterized 14 PG genes from the salivary glands of Apolygus lucorum, a pestiferous mirid bug in cotton, fruit trees and other crops in China. BLAST search analysis showed that the amino acid sequences deduced from transcripts of the PG genes were closely related to PGs from other mirid bugs. Phylogenetic analysis showed that the PGs of mirid bugs had six main branches, PG1-PG6 (Genbank accession numbers: KF881899~KF881912. We investigated the mRNA expression patterns of the A. lucorum PG genes using real-time PCR. All 14 PGs were expressed significantly higher in the salivary glands than in other tissues (head, thorax, abdomen, leg and wing. For eggs and nymphs, the expression levels of these PGs were much higher in the 5th instar stage than in the egg, and 1st and 3rd instar stages. The PG expression levels in 1-day-old adults were very low, and increased in 5, 20 and 30-day-old adults. Additionally, PG expression levels were generally similar between males and females. The possible physiological functions of PGs in A. lucorum were discussed.

  9. Life table parameters of three Mirid Bug (Adelphocoris species (Hemiptera: Miridae under contrasted relative humidity regimes.

    Directory of Open Access Journals (Sweden)

    Hongsheng Pan

    Full Text Available The genus Adelphocoris (Hemiptera: Miridae is a group of important insect pests of Bt cotton in China. The three dominant species are A. lineolatus, A. suturalis, and A. fasciaticollis, and these species have different population dynamics. The causal factors for the differences in population dynamics have not been determined; one hypothesis is that humidity may be important for the growth of Adelphocoris populations. In the laboratory, the demographic parameters of the three Adelphocoris species were compared when the mirid bugs were subjected to various levels of relative humidity (40, 50, 60, 70 and 80% RH. Middle to high levels of RH (60, 70 and 80% were associated with higher egg and nymph survival rates and increased adult longevity and female fecundity. Lower humidity levels (40 and 50% RH had negative effects on the survival of nymphs, adult longevity and fecundity. The intrinsic rate of increase (rm, the net reproductive rate (R0 and the finite rate of increase (λ for each Adelphocoris species increased with increasing RH. Significant positive relationships were found between RH and the life table parameters, rm, R0 and λ for the three Adelphocoris species. These results will help to better understand the phenology of the three Adelphocoris species, and the information can be used in population growth models to optimize pest forecasting and management strategies for these key pests.

  10. Plant Essential Oils Synergize and Antagonize Toxicity of Different Conventional Insecticides against Myzus persicae (Hemiptera: Aphididae.

    Directory of Open Access Journals (Sweden)

    Nicoletta Faraone

    Full Text Available Plant-derived products can play an important role in pest management programs. Essential oils from Lavandula angustifolia (lavender and Thymus vulgaris (thyme and their main constituents, linalool and thymol, respectively, were evaluated for insecticidal activity and synergistic action in combination with insecticides against green peach aphid, Myzus persicae (Sulzer (Hemiptera: Aphididae. The essential oils and their main constituents exerted similar insecticidal activity when aphids were exposed by direct sprays, but were non-toxic by exposure to treated leaf discs. In synergism experiments, the toxicity of imidacloprid was synergized 16- to 20-fold by L. angustifolia and T. vulgaris essential oils, but far less synergism occurred with linalool and thymol, indicating that secondary constituents of the oils were probably responsible for the observed synergism. In contrast to results with imidacloprid, the insecticidal activity of spirotetramat was antagonized by L. angustifolia and T. vulgaris essential oils, and linalool and thymol. Our results demonstrate the potential of plant essential oils as synergists of insecticides, but show that antagonistic action against certain insecticides may occur.

  11. Characterization of resistance to adult spittlebugs (Hemiptera: Cercopidae) in Brachiaria spp.

    Science.gov (United States)

    Aguirre, Lina M; Cardona, César; Miles, John W; Sotelo, Guillermo

    2013-08-01

    Nymphs and adults of several spittlebug (Hemiptera: Cercopidae) species are key pests of forage brachiariagrasses (Brachiaria spp.) in tropical America. To support current breeding programs, a series of experiments aimed at characterizing the mechanisms of resistance to adult feeding damage were carried out. Five genotypes were used: two susceptible checks (CIAT 0606 and CIAT 0654) and three nymph-resistant genotypes (CIAT 36087, CIAT 6294, and SX01NO/0102). Test insects were Aeneolamia varia (F.), A. reducta (Lallemand), and Zulia carbonaria (Lallemand). The nymph-resistant genotypes showed tolerance to all spittlebug species tested. Tolerance in these genotypes can be classified as only moderate given the extent of losses (60-80%) caused by both female and male adults. None of the nymph-resistant genotypes had antibiotic effects on adults feeding on foliage. The results also indicated that antixenosis for feeding is not a plausible explanation for lower damage scores and less biomass losses in resistant genotypes. The fact that adult longevity (usually 8 d) was not affected when the adults were forced to feed on roots of a genotype with strong antibiotic resistance to nymphs is regarded as additional evidence that resistances to nymphs and to adults in Brachiaria are largely independent.

  12. Heterochromatin base pair composition and diversification in holocentric chromosomes of kissing bugs (Hemiptera, Reduviidae)

    Science.gov (United States)

    Bardella, Vanessa Bellini; Pita, Sebastián; Vanzela, André Luis Laforga; Galvão, Cleber; Panzera, Francisco

    2016-01-01

    The subfamily Triatominae (Hemiptera, Reduviidae) includes 150 species of blood-sucking insects, vectors of Chagas disease or American trypanosomiasis. Karyotypic information reveals a striking stability in the number of autosomes. However, this group shows substantial variability in genome size, the amount and distribution of C-heterochromatin, and the chromosome positions of 45S rDNA clusters. Here, we analysed the karyotypes of 41 species from six different genera with C-fluorescence banding in order to evaluate the base-pair richness of heterochromatic regions. Our results show a high heterogeneity in the fluorescent staining of the heterochromatin in both autosomes and sex chromosomes, never reported before within an insect subfamily with holocentric chromosomes. This technique allows a clear discrimination of the heterochromatic regions classified as similar by C-banding, constituting a new chromosome marker with taxonomic and evolutionary significance. The diverse fluorescent patterns are likely due to the amplification of different repeated sequences, reflecting an unusual dynamic rearrangement in the genomes of this subfamily. Further, we discuss the evolution of these repeated sequences in both autosomes and sex chromosomes in species of Triatominae. PMID:27759763

  13. A laboratory and field condition comparison of life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Hosseini-Tabesh Behnaz

    2015-01-01

    Full Text Available Life table studies are essential tools for understanding population dynamics. The life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae feeding on the host plant, Hibiscus syriacus L. were studied under laboratory (25±1°C and relative humidity of 65±5% and a photoperiod of 16L : 8D h and field conditions (23-43°C, and relative humidity of 27-95%. The data were analysed using the age-stage, two-sex life table theory. The life table studies were started with 50 and 40 nymphs in laboratory and field conditions, respectively. Under laboratory conditions, A. gossypii reared on H. syriacus had a higher survival rate, fecundity, and longevity than those reared under field conditions. When reared under field conditions, A. gossypii had a longer nymphal developmental time, shorter adult longevity, and lower fecundity than those reared under laboratory conditions. The intrinsic rate of increase (r, net reproductive rate (R0, and the finite rate of increase (λ under laboratory conditions, were higher than those obtained under field conditions. Nevertheless, there were no significant differences in the mean generation time T (days between field and laboratory conditions. In the present study, the results clearly showed that life table parameters of A. gossypii were significantly different under field and laboratory conditions. These results could help us to understand the A. gossypii population dynamics under field conditions. The results could also help us make better management decisions for economically important crops

  14. Within-plant distribution and binomial sampling of Pentalonia nigronervosa (Hemiptera: Aphididae) on banana.

    Science.gov (United States)

    Robson, Jacqueline D; Wright, Mark G; Almeida, Rodrigo P P

    2006-12-01

    The banana aphid, Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae), infests banana (Musa spp.) worldwide. Pentalonia nigronervosa is the vector of Banana bunchy top virus (family Nanoviridae, genus Babuvirus) the etiological agent of Banana bunchy top disease (BBTD). BBTD is currently the most serious problem affecting banana in Hawaii. Despite the importance of this vector species, little is known about its biology or ecology. There are also no sampling plans available for P. nigronervosa. We conducted field surveys to develop a sampling plan for this pest. Ten plots were surveyed on seven commercial banana farms on the island of Oahu, HI, for the presence of P. nigronervosa on banana plantlets. We found aphids more frequently near the base of plants, followed by the newest unfurled leaf at the top of the plant. Aphids were least likely to be located on leaves in between the top and bottom of the plant. Aphid infestation on surveyed plots ranged from 8 to 95%. We developed a sequential binomial sampling plan based on our surveys. We also discovered that the within-plant distribution of P. nigronervosa is an important factor to consider when sampling for this pest. Our sampling plan will assist in the development of sustainable management practices for banana production.

  15. Life History of the Camelthorn Gall Leafhopper, Scenergates viridis (Vilbaste (Hemiptera, Cicadellidae

    Directory of Open Access Journals (Sweden)

    Roman Rakitov

    2012-01-01

    Full Text Available The world’s only member of Hemiptera Auchenorrhyncha known to form true galls, the leafhopper Scenergates viridis (Vilbaste (Cicadellidae, transforms leaves of camelthorn (Alhagi maurorum Medikus, Fabaceae into pod-like chambers, up to 35 mm long, inside which individual leafhoppers develop, mate, and lay eggs. At the study site 40 km SE of Bukhara (Uzbekistan, two generations develop annually. First-instar nymphs cause young leaves to fold along the midrib. The subsequent development takes place inside the tightly closed growing gall, plugged at both ends with a mixture of leafhopper excrement, brochosomes, and crushed exuviae. These plugs act as mechanical barriers and sticky traps for intruders. The inner surface of the gall, lined with brochosomes and wax platelets, is hydrophobic. Adult males emerge from their galls and squeeze into female galls. Fertilized females insert an average of 146 eggs under the gall’s inner epidermis and remain inside, possibly protecting the brood, until they die. The walls of the galls containing eggs are approximately three times thicker than regular leaves. The galls are subject to predation by Gelechiidae caterpillars; the eggs of the leafhopper are parasitized by two species of Trichogrammatidae and one Mymaridae (Hymenoptera, and its larvae by one species of Pipunculidae (Diptera.

  16. Seasonal variation of Hemiptera community of a temple pond of Cachar District, Assam, northeastern India

    Directory of Open Access Journals (Sweden)

    K. Das

    2012-09-01

    Full Text Available The study records seven families, 11 genera and 14 species of hemipteran insect community in different seasons in a temple pond near Silchar, Cachar District, Assam, northeastern India. The pond is very rich in macrophytes like Nelumbo nucifera (Water Lotus, Hygrorhiza aristata (Indian Lotus, Cynodon dactylon (Bermuda Grass, Philotria sp. etc. The hemipteran families recorded in the system were Corixidae, Gerridae, Aphididae, Mesoveliidae, Notonectidae, Nepidae and Belostomatidae. The species were Micronecta haliploides, Micronecta (Basileonecta scutellaris scutellaris (Stål (Corixidae; Neogerris parvula (Stål, Limnogonus nitidus (Mayr, Tenagogerris sp., Rhagadotarsus sp. (Gerridae; Enithares ciliata (Fabricius, Anisops lundbladiana Landsbury, (Notonectidae; Diplonychus rusticus (Fabricius and Diplonychus annulatus (Fabricius (Belostomatidae, Rhopalosiphum nymphaeae (Linnaeus (Aphididae, Ranatra elongata (Fabricius, Ranatra varipes varipes (Stål (Nepidae and Mesovelia vittigera Horváth (Mesoveliidae. The highest population of Hemiptera was recorded during the post-monsoon followed by the pre-monsoon and the monsoon periods. The lowest was recorded in the winter. Shannon Weiner diversity index (H/ and evenness index (J/ showed the highest diversity and evenness during the post monsoon period. Berger Parker index of dominance (d was found highest in winter. In winter both diversity and density were the lowest. The study revealed the presence of four dominant species and three sub-dominant species in the pond. Insect diversity did not show any significant relationship with the environmental variables.

  17. The foraging behavior of Diaeretiella rapae (Hymenoptera: Braconidae on Diuraphis noxia (Hemiptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Tazerouni Zahra

    2011-01-01

    Full Text Available Host stage preference, functional response and mutual interference of Diaeretiella rapae (McIntosh (Hymenoptera: Braconidae: Aphidiinae on Diuraphis noxia (Mordvilko (Hemiptera: Aphididae were investigated under defined laboratory conditions (20±1°C; 60±5% relative humidity; 16 h light/8 h dark photoperiod. Nicholson’s model and linear regression were used to determine per capita search-efficiency and the interference coefficient, respectively. There was a significant difference between the rates of parasitism on different stages of D. noxia. The highest parasitism percentage was observed on the third instar nymphs of D. noxia in both choice and no-choice preference tests. Results of logistic regression revealed a type II functional response. The estimated values of search-efficiency (a and handling time (Th were 0.072 h-1 and 0.723 h, respectively. The maximum attack rate was calculated to be 33.22. The per capita search-efficiency decreased from 0.011 to 0.004 (h-1 as parasitoid densities increased from 1 to 8. Therefore, different host-parasitoid ratios can affect the efficacy of D. rapae.

  18. Impact of Feeding on Contaminated Prey on the Life Parameters of Nesidiocoris Tenuis (Hemiptera: Miridae) Adults

    Science.gov (United States)

    Wanumen, Andrea Carolina; Sánchez-Ramos, Ismael; Viñuela, Elisa; Medina, Pilar; Adán, Ángeles

    2016-01-01

    Insecticide selectivity to natural enemies is an important concern in integrated pest management programs. Although there is a wide range of information concerning pesticide lethal and sublethal effects on contaminated surfaces, little is known when the route of exposure occurs at a trophic level. This study evaluates this route of pesticide intake on the omnivorous predator Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) for the first time. Under laboratory conditions, prey treated with six insecticides (flubendiamide, spirotetramat, deltamethrin, flonicamid, metaflumizone, and sulfoxaflor) were offered to N. tenuis adults for 3 days. Mortality (24, 48, and 72 h after treatment), offspring production (third until eighth day) and longevity were documented. Metaflumizone and sulfoxaflor were classified as moderately harmful products because although the percentage of mortality was only 28 and 36%, respectively, both products caused a severe decrease in offspring production and longevity. Flonicamid and flubendiamide were classified as slightly harmful products; although they did not have a lethal effect, sublethal impact was important on the parameters studied. Spirotetramat and deltamethrin were insecticides categorized as harmless. This information could be useful for selecting the most appropriate insecticides to control pests in tomato crops in which N. tenuis is a relevant biological control agent. PMID:27694345

  19. Solenopsis invicta (Hymenoptera: Formicidae), defend Phenacoccus solenopsis (Hemiptera: Pseudococcidae) against its natural enemies.

    Science.gov (United States)

    Zhou, Aiming; Lu, Yongyue; Zeng, Ling; Xu, Yijuan; Liang, Guangwen

    2013-04-01

    Mutualism is a common and important ecological phenomenon characterized by beneficial interaction between two species. Red imported fire ants, Solenopsis invicta Buren, tend honeydew-producing hemipteran insects and reduce the activity of these insects' enemies. Ant-hemipteran interactions frequently exert positive effects on the densities of hemipterans. We tested the hypothesis that ant tending can increase the densities of the mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), and reduce the densities of the mealybug's predatory and parasitic enemies, the lady beetle, Menochilus sexmaculata Fabricius (Coleoptera: Coccinellidae), and the parasitoid wasp, Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae). We found that more ants foraged on mealybug-infested hibiscus plants than on mealybug-free plants. The number of foraging ants on plants infested with high densities of mealybugs (62.5 ants per plant) was nearly six times that on mealybug-free plants (10.2 ants per plant). Experiment results showed that ant tending significantly increased the survival of mealybugs: if predatory and parasitic enemies were present, the survival of mealybugs tended by fire ants was higher than that in the absence of tending ants. Furthermore, this tending by fire ants significantly decreased the survival of lady beetle larvae. However, no apparent effect was observed on the survival of parasitoid.

  20. Development and Life Table Parameters of Phenacoccus madeirensis Green (Hemiptera: Pseudococcidae) on Four Ornamental Plants.

    Science.gov (United States)

    Tok, B; Kaydan, M B; Mustu, M; Ulusoy, M R

    2016-08-01

    The development, reproduction, and life table parameters of the Phenacoccus madeirensis Green (Hemiptera: Pseudococcidae) on four ornamental plant species, namely Pelargonium zonale (Geraniaceae), Hibiscus rosa-sinensis, Hibicus syriacus (Malvaceae), and Cestrum nocturnum (Solanaceae) were investigated under controlled conditions (25 ± 2°C, 60 ± 10% R.H., and 16 h photophase). Life table data were analyzed by using an age-stage two-sex life table. The shortest total immature developmental time of females and males for P. madeirensis was obtained on C. nocturnum (20.42 and 21.90 days, respectively). The highest fecundities were 233 and 232 eggs on C. nocturnum and H. syriacus, respectively. The intrinsic rate of increase (r  = 0.1511 day(-1)) and finite rate of increase (λ  =  1.1631 day(-1)) were the greatest when mealybugs were reared on C. nocturnum. Net reproductive rate (R 0  =  129.5 offspring) was the greatest when reared on H. syriacus, but this value was not statistically different from that on C. nocturnum. The shortest mean generation time (T  =  31.3 days) was calculated on C. nocturnum. These results indicate that C. nocturnum and H. syriacus are more suitable hosts than H. rosa-sinensis and P. zonale for P. madeirensis.

  1. Phenotypic variation and identification of Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) in China.

    Science.gov (United States)

    Zhao, Jing; Watson, Gillian W; Sun, Yang; Tan, Yongan; Xiao, Liubin; Bai, Lixin

    2014-05-23

    Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is an invasive mealybug that seriously damages cotton and other important crops. In previous studies in China, the presence of two submedian longitudinal lines of pigmented spots on the dorsum of adult females frequently has been used to identify this species. However, the present study records the occasional absence of pigmented spots in a sample from Guangxi province, China. Specimens without pigmented spots showed all the molecular and morphological characters that separate P. solenopsis from the similar species P. solani Ferris, especially the distribution of multilocular disc pores. In different geographic populations of P. solenopsis in China, mitochondrial COI and nuclear 28SrDNA genes are very similar (99.8-100%), indicating that they are conspecific. For COI, the genetic distance between P. solenopsis and P. solani is more than 3%. A map of the distribution of P. solenopsis in China is given. To help identify both pigmented and non-pigmented P. solenopsis accurately, an identification key to the 16 species of Phenacoccus found in China is provided. The key also identifies five potentially invasive Phenacoccus species not yet established in China, in case they get introduced there.

  2. Ultralow oxygen treatment for control of Planococcus ficus (Hemiptera: Pseudococcidae) on grape benchgrafts.

    Science.gov (United States)

    Liu, Yong-Biao; Bettiga, Larry J; Daane, Kent M

    2010-04-01

    Controlled atmosphere treatments with ultralow oxygen (ULO treatments) were developed successfully for control of vine mealybug, Planococcusflcus Signoret (Hemiptera: Pseudococcidae), on dormant grape (Vitis spp.) benchgrafts. At 30 ppm oxygen, 3-d ULO treatment at 25 degrees C and 4-d ULO treatment at 150C achieved complete control of all life stages of P. ficus. At a much lower oxygen level (<1 ppm), the two ULO treatments with the same exposure periods of 3 d at 25 degrees C and 4 d at 15 degrees C were tested on six table and wine grape cultivars grafted on rootstocks along with P. ficus. The benchgrafts were then potted in a greenhouse, together with untreated controls, to determine treatment effects on rootstock viability. Both ULO treatments achieved complete control of P. ficus and did not have any negative effects on vine growth, compared with the control. Results indicate that ULO treatments can be used to control P. ficus on dormant grape benchgrafts. The advantages of the ULO treatments are also discussed with respect to hot water treatments.

  3. Laboratory Evaluation of Different Insecticides against Hibiscus Mealybug, Maconellicoccus hirsutus (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Fatima, Samman; Hussain, Mubashar; Shafqat, Shama; Faheem Malik, Muhammad; Abbas, Zaheer; Noureen, Nadia; Ul Ane, Noor

    2016-01-01

    Hibiscus mealybug, Maconellicoccus hirsutus (Hemiptera: Pseudococcidae), is the major pest of many vegetables, fruits, crops, and ornamental plants causing losses to the farmers and its control has been an issue of significance in the pest management. This study was aimed at evaluating different concentrations (0.06%, 0.1%, and 0.14%) of Telsta, Advantage, Talstar, Imidacloprid, and their mixtures against hibiscus mealybug in the Laboratory of Systematics and Pest Management at University of Gujrat, Pakistan. The toxic effect was evaluated in the laboratory bioassay after 24 and 48 h of the application of insecticides. The highest mortality (95.83%) was shown by Talstar and Talstar + Imidacloprid at the concentration of 0.14% after 48 h followed by Advantage + Talstar with 87.50% mortality at 0.14% concentration after 48 h of application. The study also showed that the least effective treatment observed was Advantage + Telsta with no mortality after 24 h and 25% mortality after 48 h at 0.14% concentration. The study revealed that the concentration 0.14% was highly effective in lowering the mealybug population and insecticide mixtures were effective in reducing mealybug density. The study emphasizes the use of such insecticide mixtures to develop better management strategy for mealybug populations attacking ornamental plants. However effects of such insecticide mixtures on other organisms and biological control agents should be checked under field conditions.

  4. Plant Essential Oils Synergize and Antagonize Toxicity of Different Conventional Insecticides against Myzus persicae (Hemiptera: Aphididae).

    Science.gov (United States)

    Faraone, Nicoletta; Hillier, N Kirk; Cutler, G Christopher

    2015-01-01

    Plant-derived products can play an important role in pest management programs. Essential oils from Lavandula angustifolia (lavender) and Thymus vulgaris (thyme) and their main constituents, linalool and thymol, respectively, were evaluated for insecticidal activity and synergistic action in combination with insecticides against green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae). The essential oils and their main constituents exerted similar insecticidal activity when aphids were exposed by direct sprays, but were non-toxic by exposure to treated leaf discs. In synergism experiments, the toxicity of imidacloprid was synergized 16- to 20-fold by L. angustifolia and T. vulgaris essential oils, but far less synergism occurred with linalool and thymol, indicating that secondary constituents of the oils were probably responsible for the observed synergism. In contrast to results with imidacloprid, the insecticidal activity of spirotetramat was antagonized by L. angustifolia and T. vulgaris essential oils, and linalool and thymol. Our results demonstrate the potential of plant essential oils as synergists of insecticides, but show that antagonistic action against certain insecticides may occur.

  5. Rapid molecular identification of armored scale insects (Hemiptera: Diaspididae) on Mexican 'Hass' avocado.

    Science.gov (United States)

    Rugman-Jones, Paul F; Morse, Joseph G; Stouthamer, Richard

    2009-10-01

    'Hass' avocado, Persea americana Mill., fruit imported into California from Mexico are infested with high levels of armored scale insects (Hemiptera: Diaspididae), constituting several species. The paucity and delicate nature of morphological characters traditionally used to diagnose armored scales often require careful preparation of slide-mounted specimens and expert knowledge of the group, for their accurate identification. Here, we present a simple, quick, and accurate means to identify armored scales on Mexican avocados, based on amplification of the internal transcribed spacer two of ribosomal DNA, by using the polymerase chain reaction (PCR). This region seems to show a high level of intraspecific conformity among scale specimens originating from different localities. A suite of species-specific reverse PCR primers are combined in a single reaction, with a universal forward primer, and produce a PCR product of a unique size, that after standard gel electrophoresis, allows the direct diagnosis of six diaspidid species: Abgrallaspis aguacatae Evans, Watson & Miller; Hemiberlesia lataniae (Signoret); Hemiberlesia sp. near latania; Hemiberlesia rapax (Comstock); Acutaspis albopicta (Cockerell); and Pinnaspis strachani (Cooley). Two additional species, Diaspis miranda (Cockerell) and Diaspis sp. near miranda, also are separated from the others by using this method and are subsequently diagnosed by secondary digestion of the PCR product with the restriction endonuclease smaI.

  6. Fitness of Encarsia sophia(Hymenoptera: Aphelinidae)parasitizing Trialeurodes vaporariorum and Bemisia tabaci (Hemiptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    Chen Luo; Tong-Xian Liu

    2011-01-01

    Fitness and efficacy of Encarsia sophia(Girault & Dodd)(Hymenoptera:Aphelinidae)as a biological control agent was compared on two species of whitefly(Hemiptera: Aleyrodidae)hosts,the relatively smaller sweetpotato whitefly,Bemisia tabaci(Gennadius)biotype 'B',and the larger greenhouse whitefly,Trialeurodes vaporariorum(Westwood).Significant differences were observed on green bean(Phaseolus vulgaris L.)in the laboratory at 27± 2℃,55% ± 5% RH,and a photoperiod of 14 : 10 h(L : D).Adult parasitoids emerging from T.vaporariorum were larger than those emerging from B.tabaci,and almost all biological parameters of E.sophia parasitizing the larger host species were superior except for the developmental times of the parasitoids that were similar when parasitizing the two host species.Furthermore,parasitoids emerging from T.vaporariorum parasitized more of these hosts than did parasitoids emerging from B.tabaci.We conclude that E.sophia reared from larger hosts had better fitness than from smaller hosts.Those from either host also preferred the larger host for oviposition but were just as effective on smaller hosts.Therefore,larger hosts tended to produce better parasitoids than smaller hosts.

  7. [Characterization of the behavioral and vibrational signals in Euthyrhynchus floridanus (Hemiptera: Pentatomidae) during courtship and copulation].

    Science.gov (United States)

    Briceño, R Daniel

    2014-03-01

    Euthyrhynchus floridanus (Linnaeus) (Hemiptera: Pentatomidae) is a neotropical species belonging to the family Pentatomidae with over 4 000 species described, and is distributed from Florida to Brazil. This study describes the sexual behavior and reported for the first time the production of substrate vibrations by males and females during copulatory behavior and mating. Courtship and copulatory behavior, as well as the diverse signals, were recorded with a phonographic cartridge connected to a video camera. Female vibrations were reproduced in the absence of females and the responses by males were recorded. At least three types of substrate vibrations were distinguished in males and one in females, and these signals were characterized by their low frequency, varying from 127 to 180Hz. The sounds of E. floridianus males were significantly different in frequency, duration and number of pulses, both in courtship and in copulation, for the purring and drumming sounds. The production of sounds in this species is associated principally with mechanical, stimulatory behavior during courtship and copulation. Patterns of behavior and their relation to substrate vibrations suggest that these signals are important for the males in the context of mate location and sexual selection.

  8. Effect of vermicompost and cucumber cultivar on population growth attributes of the melon aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Razmjou, J; Mohammadi, M; Hassanpour, M

    2011-08-01

    Worldwide, the developing industry of cucumbers (Cucumis sativus L.) grown in greenhouses is threatened by damage from sucking pests, especially aphids. Among these, the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is the most serious. We tested the effect of two cucumber cultivars ('Royal' and'Storm') and three vermicompost concentrations (0 [control], 20, and 30%) in field soil on the development and fecundity rates of A. gossypii, by using a randomized complete block design with four replicates as a factorial experiment. The developmental times of nymphs reared on plants grown into the three vermicompost concentrations ranged from 5.5 (0%) to 8.7 (30%) d (on Storm) and from 4.3 (0%) to 7 (30%) d (on Royal). The developmental time of melon aphid's nymphs was greatest on plants grown in the culture medium with 30% vermicompost rate and least on plants reared in the soil without vermicompost. The intrinsic rate of natural increase (r,,) of A. gossypii ranged from 0.204 d(-1) on plants grown in the soil amended with 30% vermicompost rate (on Storm seedlings) to 0.458 d(-1) on plants grown in the soil without vermicompost (on Royal seedlings). Accordingly, our findings confirm that a combination of a low level of vermicompost and a partially resistant cucumber cultivar might play an important role in managing this aphid on cucumbers in greenhouses.

  9. Gammaproteobacteria as essential primary symbionts in the striped shield bug, Graphosoma Lineatum (Hemiptera: Pentatomidae)

    Science.gov (United States)

    Karamipour, Naeime; Mehrabadi, Mohammad; Fathipour, Yaghoub

    2016-01-01

    Many members of suborder Heteroptra harbor heritable symbiotic bacteria. Here we characterize the gut symbiotic bacterium in Graphosoma lineatum (Hemiptera: Pentatomidae) by using molecular phylogeny, real-time PCR analysis as well as light and electron microscopy observations. The microscopy observations revealed the presence of a large number of rod-shaped bacterial cells in the crypts. A very high prevalence (98 to 100%) of the symbiont infection was found in the insect populations that strongly supports an intimate association between these two organisms. Real-time PCR analysis also showed that the Gammaproteobacteria dominated the crypts. The sequences of 16sr RNA and groEL genes of symbiont showed high levels of similarity (93 to 95%) to Pantoea agglomeranse and Erwinia herbicola Gammaproteobacteria. Phylogenetic analyses placed G. lineatum symbiont in a well-defined branch, divergent from other stink bug bacterial symbionts. Co-evolutionary analysis showed lack of host-symbiont phylogenetic congruence. Surface sterilization of eggs resulted in increased pre-adult stage in the offspring (aposymbionts) in comparison to the normal. Also, fecundity, longevity, and adult stage were significantly decreased in the aposymbionts. Therefore, it seems that the symbiont might play a vital function in the host biology, in which host optimal development depends on the symbiont. PMID:27609055

  10. The hemiptera (insecta of Canada: constructing a reference library of DNA barcodes.

    Directory of Open Access Journals (Sweden)

    Rodger A Gwiazdowski

    Full Text Available DNA barcode reference libraries linked to voucher specimens create new opportunities for high-throughput identification and taxonomic re-evaluations. This study provides a DNA barcode library for about 45% of the recognized species of Canadian Hemiptera, and the publically available R workflow used for its generation. The current library is based on the analysis of 20,851 specimens including 1849 species belonging to 628 genera and 64 families. These individuals were assigned to 1867 Barcode Index Numbers (BINs, sequence clusters that often coincide with species recognized through prior taxonomy. Museum collections were a key source for identified specimens, but we also employed high-throughput collection methods that generated large numbers of unidentified specimens. Many of these specimens represented novel BINs that were subsequently identified by taxonomists, adding barcode coverage for additional species. Our analyses based on both approaches includes 94 species not listed in the most recent Canadian checklist, representing a potential 3% increase in the fauna. We discuss the development of our workflow in the context of prior DNA barcode library construction projects, emphasizing the importance of delineating a set of reference specimens to aid investigations in cases of nomenclatural and DNA barcode discordance. The identification for each specimen in the reference set can be annotated on the Barcode of Life Data System (BOLD, allowing experts to highlight questionable identifications; annotations can be added by any registered user of BOLD, and instructions for this are provided.

  11. A preliminary molecular phylogeny of planthoppers (Hemiptera: Fulgoroidea based on nuclear and mitochondrial DNA sequences.

    Directory of Open Access Journals (Sweden)

    Nan Song

    Full Text Available The planthopper superfamily Fulgoroidea (Insecta: Hemiptera is one of the most dominant groups of phytophagous insects. It comprises about 20 families, containing a total of 9000 species worldwide. Despite several recent studies, the phylogeny of Fulgoroidea is not yet satisfactorily resolved and the phylogenetic positions of several key families, especially Cixiidae, Delphacidae, Tettigometridae, Nogodinidae, Acanaloniidae and Issidae, are contentious. Here, we expand upon recent phylogenetic work using additional nuclear (18S and 28S and novel mitochondrial (16S and cytb markers. Maximum likelihood and Bayesian analyses yielded robust phylogenetic trees. In these topologies, a group containing Cixiidae and Delphacidae is recovered as the sister group to the remaining taxa. Tettigometridae is placed in a more nested position and is grouped with Caliscelidae. Sister relationships are found between Flatidae and Ricaniidae, and between Dictyopharidae and Fulgoridae. Nogodinidae and Issidae are confirmed to be non-monophyletic families. For major nodes of interest, divergence date estimates are generally older than those from the fossil record.

  12. The Spread of Nezara viridula (Hemiptera:Pentatomidae Species from its First Occurrence in Romania

    Directory of Open Access Journals (Sweden)

    Ioana Grozea

    2016-11-01

    Full Text Available Lately in horticultural agroecosystems from Romania joined several insect species autochthonous. Among these is a species of bugs known as southern green stink bugs or Nezara viridula L. (Insecta: Hemiptera: Pentatomidae. Unlike other new entrants this bug species has a diversified polifagism being present in many plants but obvious damage produce only tomato fruit. The causes are unknown. Can be found in gardens, green spaces and parks. Often is observed in vegetable gardens where populations comprise all stages (egg, larva/nymph, adult. Although it has African origins of a warm area is interesting installation and survival in temperate zones like those in Europe. Presence in Europe appears to be more random which excludes primarily spread through the neighborhood. By observations made in west of Romania, during 2010-2015 we wanted to watch the evolution of the insect from the first point of occurrence (Timișoara, 2010. Also, were monitored tomato crops and ornamentals in gardens and green spaces from 5 counties. Only in four monitored counties it was observed this species. Most adults and larvae were registered in Timis county (5-6 adults or 7-8 larvae/tomato plant and 10 -11 adults or 15-20 larvae/ornamental shrub. In our country the insect has proven to be capable of a rapid spread in a relatively short time interval including surrounding counties.

  13. Spatial Distribution of Adults of Triozoida limbata (Enderlein) (Hemiptera: Triozidae) in Guava Plants.

    Science.gov (United States)

    Marcelino, M C S; Barbosa, J C

    2016-04-01

    The psyllid Triozoida limbata (Enderlein) (Hemiptera: Triozidae) is a major pest in guava, feeding primarily on new shoots. Despite its importance, there are no studies on the spatial distribution of T. limbata on guava. Such studies are needed to establish sequential sampling plans for decision making in pest control. Thus, an experiment was carried out in a 9-year-old commercial guava orchard divided into 100 sampling units or plots. Double-sided yellow sticky traps were placed on one plant per plot (sample unit) to capture and monitor T. limbata adults from April 2011 to May 2012. To determine the insect distribution in the area, we calculated the variance-to-mean ratio index (I), the Morisita index (I δ ), Green's coefficient (Cx), and the k exponent of the negative binomial distribution. Most of the samples showed that the adults had a moderate to highly aggregated distribution. Statistical models were also used to study the pest spatial distribution by fitting the number of adults captured to the Poisson and negative binomial distributions. The negative binomial distribution model best fitted the data of the number of adult psyllids captured by the traps, which is consistent with an aggregated distribution.

  14. Characterization of a newly discovered symbiont of the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Bing, Xiao-Li; Yang, Jiao; Zchori-Fein, Einat; Wang, Xiao-Wei; Liu, Shu-Sheng

    2013-01-01

    Bemisia tabaci (Hemiptera: Aleyrodidae) is a species complex containing >28 cryptic species, some of which are important crop pests worldwide. Like many other sap-sucking insects, whiteflies harbor an obligatory symbiont, "Candidatus Portiera aleyrodidarum," and a number of secondary symbionts. So far, six genera of secondary symbionts have been identified in B. tabaci. In this study, we report and describe the finding of an additional bacterium in the indigenous B. tabaci cryptic species China 1 (formerly known as B. tabaci biotype ZHJ3). Phylogenetic analysis based on the 16S rRNA and gltA genes showed that the bacterium belongs to the Alphaproteobacteria subdivision of the Proteobacteria and has a close relationship with human pathogens of the genus Orientia. Consequently, we temporarily named it Orientia-like organism (OLO). OLO was found in six of eight wild populations of B. tabaci China 1, with the infection rate ranging from 46.2% to 76.8%. Fluorescence in situ hybridization (FISH) of B. tabaci China 1 in nymphs and adults revealed that OLOs are confined to the bacteriome and co-occur with "Ca. Portiera aleyrodidarum." The vertical transmission of OLO was demonstrated by detection of OLO at the anterior pole end of the oocytes through FISH. Quantitative PCR analysis of population dynamics suggested a complex interaction between "Ca. Portiera aleyrodidarum" and OLO. Based on these results, we propose "Candidatus Hemipteriphilus asiaticus" for the classification of this symbiont from B. tabaci.

  15. The controlling role of Panonychus citri by "Lümanyuan" in the filed and the measurement of its acute toxicity to Carassius auratus%“绿满园”对柑桔红蜘蛛的田间防治效果及对金鱼的毒性测定

    Institute of Scientific and Technical Information of China (English)

    乔虎平; 王金亮; 江庆红; 云月利; 王维; 彭宇

    2013-01-01

    测定“绿满园”水剂对柑桔红蜘蛛Panonychus citri的田间防治效果及对非靶标生物金鱼Carassius auratus 的急性毒性.结果表明,64%“绿满园”水剂800倍和1 000倍稀释液在施药后7d和15d对柑桔红蜘蛛的防治效果均极显著地高于对照杀螨剂:15%扫螨净和57%炔螨特,其中以800倍稀释液防治效果最好,15d的防效达97.21%,800倍和1 000倍稀释液的防治效果差异不明显.金鱼的死亡率随“绿满园”浓度的升高和染毒时间的延长逐渐增加.“绿满园”水剂对金鱼的急性毒性小于阿维菌素.%The controlling role of Panonychus citri by "Lumanyuan" in the filed and the measurement of its acute toxicity to Carassius auratus were carried out. The results showed that, 15 days after spraying, the controlling roles of 800 folds and 1 000 folds dilution of 64% "Lumanyuan" to P. citri was obviously higher than 15% pyridaben and 57% propargite. 800 fold dilution of "Lumanyuan" had the best controlling role to P. citri and the controlling effect was 97. 21%. There was no significant difference on controlling effects between 800 folds and 1 000 folds dilution of "Lumanyuan" to P. citri. The mortalities of C. auratus increased with the rise of the concentration and treatment time of "Lumanyuan" and "Lumanyuan" has lower acute toxicity to C. auratus than avermectin.

  16. Estados de desarrollo y biología de tres especies de Lygaeinae (Hemiptera-Heteroptera: Lygaeoidea: Lygaeidae Life stages and biology of three species of Lygaeinae (Hemiptera-Heteroptera: Lygaeoidea: Lygaeidae

    Directory of Open Access Journals (Sweden)

    Luis Cervantes-Peredo

    2007-12-01

    Full Text Available Se describen los estados de desarrollo (huevo, ninfas y adulto de 3 especies de Lygaeinae (Hemiptera-Heteroptera: Lygaeoidea: Lygaeidae, Anochrostomus formosus (Blanchard principalmente asociada con especies de Asteraceae y Convolvulaceae, y Lygaeus reclivatus reclivatus(Say y Oncopeltus (Oncopeltus sexmaculatus (Stål asociadas con Asclepiadaceae. Las descripciones están basadas en ejemplares colectados en los estados de Oaxaca y Guerrero (México y criados en el laboratorio. Se ilustra cada uno de los estadios y se incluyen notas acerca de su biología y plantas huéspedes.The life stages (egg, nymphs, and adult of 3 species of Lygaeinae (Hemiptera-Heteroptera: Lygaeoidea: Lygaeidae are described. Anochrostomus formosus (Blanchard is mainly associated with species of Asteraceae and Convolvulaceae, whereas Lygaeus reclivatus reclivatus (Say and Oncopeltus (Oncopeltus sexmaculatus (Stål are associated with Asclepiadaceae. Descriptions are based on individuals collected in the states of Oaxaca and Guerrero (Mexico, and reared in laboratory. Illustrations of each instar are also included, as well as notes about their biology and host plants.

  17. Nuevos registros de Hesperolabops nigriceps Reuter (Hemiptera: Miridae en el oriente del Estado de México New records of Hesperolabops nigriceps Reuter (Hemiptera: Miridae in the east of Mexico State

    Directory of Open Access Journals (Sweden)

    Marina Ruiz-Machuca

    Full Text Available El nopal tunero (Opuntia spp. se cultiva en todo el país, pero sólo en el Estado de México se concentra cerca de 35% de la producción nacional de tuna. Opuntia ficus-indica L. (Miller, es la especie predominante en la obtención de tunas, pero se carece de información que identifiquen taxonómicamente algunas plagas del cultivo; tal es el caso de la chinche roja (Hemiptera: Miridae. se realizaron colectas sistemáticas de este insecto sobre nopales (Opuntia spp., en diferentes municipios del Estado de México en 2008 y se encontraron 20 nuevos registros de Hesperolabops nigriceps Reuter.The prickly pear nopal (Opuntia spp. is cultivated throughout entire country, but 35% of the national production is found only within State of Mexico. Opuntia ficus-indica L. (Miller is the predominant species for obtaining prickly pears, but there is not any information available that would taxonomically identify some plagues particular to this crop; such is the case of red bug (Hemiptera: Miridae. Some of these insects were gathered from prickly pear nopal (Opuntia spp. in different municipalities of State of Mexico in 2008 and 20 new cases of Hesperolabops nigriceps Reuter were found.

  18. Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton

    Directory of Open Access Journals (Sweden)

    Martin D. Oliveira

    2014-03-01

    Full Text Available Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton. The striped mealybug, Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae, is a widely distributed and polyphagous pest species, which naturally occurs on cotton plants in Brazil. This study evaluated the establishment and population growth as well as the within-plant distribution of F. virgata on four cotton cultivars: CNPA 7H (white fibers, BRS Verde, BRS Safira, and BRS Rubi (colored fibers. The experiment was conducted in a complete randomized design with four treatments (cultivars and 18 replications of each. Thus, cotton plants of each cultivar were infested with 100 newly hatched nymphs of F. virgata. The number of adult female mealybugs and the total number of mealybugs per plant were quantified, respectively, at 25 and 50 days after infestation. The developmental and pre-reproductive periods were also determined. Furthermore, we verified the distribution of F. virgata on the plant parts at 25 and 50 days after infestation. Ferrisia virgata showed similar growth of 412-fold in the four cotton cultivars studied. Also, the nymphs were spread on infested leaves; the secondgeneration nymphs were spread and established in all plant parts. Our results characterize F. virgata as having much potential as an important cotton pest in Brazil.

  19. OCORRÊNCIA DE Gryon gallardoi (BRETHES (HYMENOPTERA: SCELIONIDAE PARASITANDO OVOS DE Leptoglossus zonatus (DALLAS (HEMIPTERA: COREIDAE EM ITUMBIARA, GOIÁS, BRASIL OCCURRENCE OF Gryon gallardi (BRETHES (HYMENOPTERA: SCELIONIDAE PARASITING EGGS OF Leptoglossus zonatus (DALLAS (HEMIPTERA: COREIDAE IN ITUMBIARA, GOIÁS, BRAZIL

    Directory of Open Access Journals (Sweden)

    Carlos Henrique Marchiori

    2007-09-01

    Full Text Available

    Este trabalho relata a primeira ocorrência, em Goiás, de Gryon gallardoi (Bréthes (Hymenoptera: Scelionidae parasitando ovos de Leptoglossus zonatus (Dallas (Hemiptera: Coreidae, em milho cultivar Dekalb 601, no município de Itumbiara, Goiás, Brasil.

    PALAVRAS-CHAVE: Hymenoptera; Hemiptera; parasitóides; controle natural.

    This work reports the first occurrence in Itumbiara, Goiás, Brazil, of Gryon gallardoi (Bréthes (Hymenoptera: Scelionidae parasitizing eggs of Leptoglossus zonatus (Dallas (Hemiptera: Coreidae in maize.

    KEY-WORDS: Hymenoptera; Hemiptera; parasitoids; natural controle.

  20. Regular LAMP and fast LAMP for the detection of Xanthomonas axonopodis pv.citri%柑橘溃疡病菌的普通LAMP及快速LAMP检测方法的建立

    Institute of Scientific and Technical Information of China (English)

    张仑; 殷幼平; 吴瑜佳; 王中康

    2013-01-01

    This study is aimed to establish the regular LAMP and fast LAMP for the detection of Xanthomonas axonopodis pv.citri and make it useful for the grassroots quarantine departments.A specific region of the genome of X.axonopodis pv.citri was used for the design of regular LAMP and fast LAMP primers; the regular LAMP and fast LAMP detection system were established by optimization of reaction conditions; the specificity of the system was verified using genomic DNA of several reference strains and healthy citrus leaves by using a series of gradient dilution of DNA solution of X.axonopodis pv.citri and bacterial suspension.Bacterial suspension and DNA sensitivity of regular LAMP system reached 2.25 × 104 cfu and 2.03× 10-1 ng,respectively,while those of fast LAMP system reached 2.25 cfu and 2.03× 10-5 ng,respectively.In the specificity test,both regular LAMP and fast LAMP system showed high and identical specificity.The total time for the fast LAMP reaction was within 30 minutes,only half of that for the regular LAMP,greatly improving the efficiency of the analysis.The fast LAMP system was ten thousand times as sensitive as the regular LAMP system.Regular LAMP and fast LAMP for the detection of X.axonopodis pv.citri was successfully established.Regular LAMP and fast LAMP system provide a new,fast and easy way for the detection of X.axonopodis pv.citri.%建立柑橘溃疡病菌的普通LAMP和快速LAMP检测方法,使其能应用于基层检验检疫部门对病害的快速检测.利用柑橘溃疡病菌基因组特有的保守区域设计LAMP引物,通过优化反应条件,建立柑橘溃疡病菌的普通LAMP检测体系;在普通LAMP引物的基础上设计一对环引物,建立柑橘溃疡病菌的快速LAMP检测体系,并以多种参比菌DNA以及健康柑橘叶片基因组DNA为模板对普通LAMP和快速LAMP检测体系的特异性进行了验证,利用柑橘溃疡病菌菌液和DNA溶液梯度稀释液对普通LAMP和快速LAMP检测体系的灵敏度进

  1. Phylogenetic analysis of the true water bugs (Insecta: Hemiptera: Heteroptera: Nepomorpha: evidence from mitochondrial genomes

    Directory of Open Access Journals (Sweden)

    Xie Qiang

    2009-06-01

    Full Text Available Abstract Background The true water bugs are grouped in infraorder Nepomorpha (Insecta: Hemiptera: Heteroptera and are of great economic importance. The phylogenetic relationships within Nepomorpha and the taxonomic hierarchies of Pleoidea and Aphelocheiroidea are uncertain. Most of the previous studies were based on morphological characters without algorithmic assessment. In the latest study, the molecular markers employed in phylogenetic analyses were partial sequences of 16S rDNA and 18S rDNA with a total length about 1 kb. Up to now, no mitochondrial genome of the true water bugs has been sequenced, which is one of the largest data sets that could be compared across animal taxa. In this study we analyzed the unresolved problems in Nepomorpha using evidence from mitochondrial genomes. Results Nine mitochondrial genomes of Nepomorpha and five of other hemipterans were sequenced. These mitochondrial genomes contain the commonly found 37 genes without gene rearrangements. Based on the nucleotide sequences of mt-genomes, Pleoidea is not a member of the Nepomorpha and Aphelocheiroidea should be grouped back into Naucoroidea. Phylogenetic relationships among the superfamilies of Nepomorpha were resolved robustly. Conclusion The mt-genome is an effective data source for resolving intraordinal phylogenetic problems at the superfamily level within Heteroptera. The mitochondrial genomes of the true water bugs are typical insect mt-genomes. Based on the nucleotide sequences of the mt-genomes, we propose the Pleoidea to be a separate heteropteran infraorder. The infraorder Nepomorpha consists of five superfamilies with the relationships (Corixoidea + ((Naucoroidea + Notonectoidea + (Ochteroidea + Nepoidea.

  2. Recilia banda Kramer (Hemiptera: Cicadellidae), a vector of Napier stunt phytoplasma in Kenya

    Science.gov (United States)

    Obura, Evans; Midega, Charles A. O.; Masiga, Daniel; Pickett, John A.; Hassan, Mohamed; Koji, Shinsaku; Khan, Zeyaur R.

    2009-10-01

    Napier grass ( Pennisetum purpureum) is the most important fodder crop in smallholder dairy production systems in East Africa, characterized by small zero-grazing units. It is also an important trap crop used in the management of cereal stemborers in maize in the region. However, production of Napier grass in the region is severely constrained by Napier stunt disease. The etiology of the disease is known to be a phytoplasma, 16SrXI strain. However, the putative insect vector was yet unknown. We sampled and identified five leafhopper and three planthopper species associated with Napier grass and used them as candidates in pathogen transmission experiments. Polymerase chain reaction (PCR), based on the highly conserved 16S gene, primed by P1/P6-R16F2n/R16R2 nested primer sets was used to diagnose phytoplasma on test plants and insects, before and after transmission experiments. Healthy plants were exposed for 60 days to insects that had fed on diseased plants and acquired phytoplasma. The plants were then incubated for another 30 days. Nested PCR analyses showed that 58.3% of plants exposed to Recilia banda Kramer (Hemiptera: Cicadellidae) were positive for phytoplasma and developed characteristic stunt disease symptoms while 60% of R. banda insect samples were similarly phytoplasma positive. We compared the nucleotide sequences of the phytoplasma isolated from R. banda, Napier grass on which these insects were fed, and Napier grass infected by R. banda, and found them to be virtually identical. The results confirm that R. banda transmits Napier stunt phytoplasma in western Kenya, and may be the key vector of Napier stunt disease in this region.

  3. What is the economic threshold of soybean aphids (Hemiptera: Aphididae) in enemy-free space?

    Science.gov (United States)

    McCarville, M T; Kanobe, C; MacIntosh, G C; O'Neal, M

    2011-06-01

    Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a serious pest of soybean, Glycine max (L.) Merr., in the North Central United States. Current management recommendations rely on the application of insecticides based on an economic threshold (ET) of 250 aphids per plant. Natural enemies are important in slowing the increase of aphid populations and can prevent them from reaching levels that can cause economic losses. However, biological control of A. glycines is inconsistent and can be affected negatively by the intensity of agricultural activity. We measured the impact of a natural-enemy-free environment on the capacity of the current ET to limit yield loss. In 2008 and 2009, caged microplots were assigned to one of three treatments: plants kept aphid-free (referred to as the control), plants that experienced a population of 250 aphids per plant (integrated pest management [IPM]), and plants that experienced unlimited aphid population growth (unlimited). The population growth rate of aphids in the unlimited treatment for the 10 d after the application of insecticides to the IPM treatment was calculated using linear regression. The linear equation was solved to determine the mean number of days between the ET and the EIL for an aphid population in absence of predators. The number of days was determined to be 6.97 +/- 1.11 d. The 2-yr average yield for the IPM treatment was 99.93% of the control treatment. Our study suggests the current soybean aphid ET of 250 aphids per plant can effectively protect yield even if the impact of natural enemies is reduced.

  4. Seasonal Effects on the Population, Morphology and Reproductive Behavior of Narnia femorata (Hemiptera: Coreidae).

    Science.gov (United States)

    Cirino, Lauren A; Miller, Christine W

    2017-01-17

    Many insects are influenced by the phenology of their host plants. In North Central Florida, Narnia femorata (Hemiptera: Coreidae) spends its entire life cycle living and feeding on Opuntia mesacantha ssp. lata. This cactus begins producing flower buds in April that lead to unripe green fruit in June that ripen into red fruit through December. Many morphological and behavioral characteristics of N. femorata are known to be affected by cactus phenology in a controlled laboratory setting, including the degree of sexual dimorphism and mating behavior. Our goal with this study was to determine if similar phenotypic changes of N. femorata occurred over time in the wild, and the extent to which these changes were concordant with phenological changes in its host plant. Further, we investigate the length of the insect mouthparts (beak) over time. Ongoing work has suggested that beak length may change across cohorts of developing insects in response to feeding deep within cactus fruit where seed and pulp depth decrease as the fruit ripens. Our results revealed a drop in cactus fruit abundance between the months of July through October 2015 as cactus fruits turned red and ripened. Simultaneously, the average body size of both males and females of N. femorata declined at two sampled sites. Male hind femora (a sexually-selected weapon) decreased disproportionately in size over time so that males later in the year had relatively smaller hind femora for their body size. The sex-specific patterns of morphological change led to increased sexual-size dimorphism and decreased sexual dimorphism for hind femora later in the year. Further, we found that beak length decreased across cohorts of insects as cactus fruit ripened, suggesting phenotypic plasticity in mouthpart length. Behavioral studies revealed that female readiness to mate increased as the season progressed. In sum, we found pronounced changes in the phenotypes of these insects in the field. Although this study is far from

  5. Early-season host switching in Adelphocoris spp. (Hemiptera: Miridae of differing host breadth.

    Directory of Open Access Journals (Sweden)

    Hongsheng Pan

    Full Text Available The mirid bugs Adelphocoris suturalis (Jakovlev, Adelphocoris lineolatus (Goeze and Adelphocoris fasciaticollis (Reuter (Hemiptera: Miridae are common pests of several agricultural crops. These three species have vastly different geographical distributions, phenologies and abundances, all of which are linked to their reliance on local plants. Previous work has shown notable differences in Adelphocoris spp. host use for overwintering. In this study, we assessed the extent to which each of the Adelphocoris spp. relies on some of its major overwinter hosts for spring development. Over the course of four consecutive years (2009-2012, we conducted population surveys on 77 different plant species from 39 families. During the spring, A. fasciaticollis used the broadest range of hosts, as it was found on 35 plant species, followed by A. suturalis (15 species and A. lineolatus (7 species. Abundances of the species greatly differed between host plants, with A. fasciaticollis reaching the highest abundance on Chinese date (Ziziphus jujuba Mill., whereas both A. suturalis and A. lineolatus preferred alfalfa (Medicago sativa L.. The host breadths of the three Adelphocoris spp. differed greatly between subsequent spring and winter seasons. The generalist species exhibited the least host fidelity, with A. suturalis and A. lineolatus using 8 of 22 and 4 of 12 overwinter host species for spring development, respectively. By contrast, the comparative specialist A. fasciaticollis relied on 9 of its 11 overwinter plants as early-season hosts. We highlight important seasonal changes in host breadth and interspecific differences in the extent of host switching behavior between the winter and spring seasons. These findings benefit our understanding of the evolutionary interactions between mirid bugs and their host plants and can be used to guide early-season population management.

  6. Jumping performance of flea hoppers and other mirid bugs (Hemiptera, Miridae).

    Science.gov (United States)

    Burrows, M; Dorosenko, M

    2017-02-13

    The order Hemiptera includes jumping insects with the fastest take-off velocities, all generated by catapult mechanisms. It also contains the large family Miridae or plant bugs. Here we analysed the jumping strategies and mechanisms of six mirid species from high speed videos and from the anatomy of their propulsive legs and conclude that they use a different mechanism in which jumps are powered by the direct contractions of muscles. Three strategies were identified. First, jumping was propelled only by movements of the middle and hind legs which were respectively 140% and 190% longer than the front legs. In three species with masses ranging from 3.4 to 12.2 mg, depression of the coxo-trochanteral and extension of femoro-tibial joints accelerated the body in 8-17 ms to take-off velocities of 0.5 to 0.8 m s(- 1) The middle legs lost ground contact 5-6 ms before take-off so that the hind legs generated the final propulsion. The power requirements could be met by the direct muscle contractions so that catapult mechanisms are not implicated. Second, other species combined the same leg movements with wing beating to generate take-off during a wing downstroke. In the third strategy, up to four wing beat cycles preceded take-off and were not assisted by leg movements. Take-off velocities were reduced and acceleration times lengthened. Other species from the same habitat did not jump. The lower take-off velocities achieved by powering jumping by direct muscle contractions may be offset by eliminating the time taken to load catapult mechanisms.

  7. Seasonal Effects on the Population, Morphology and Reproductive Behavior of Narnia femorata (Hemiptera: Coreidae)

    Science.gov (United States)

    Cirino, Lauren A.; Miller, Christine W.

    2017-01-01

    Many insects are influenced by the phenology of their host plants. In North Central Florida, Narnia femorata (Hemiptera: Coreidae) spends its entire life cycle living and feeding on Opuntia mesacantha ssp. lata. This cactus begins producing flower buds in April that lead to unripe green fruit in June that ripen into red fruit through December. Many morphological and behavioral characteristics of N. femorata are known to be affected by cactus phenology in a controlled laboratory setting, including the degree of sexual dimorphism and mating behavior. Our goal with this study was to determine if similar phenotypic changes of N. femorata occurred over time in the wild, and the extent to which these changes were concordant with phenological changes in its host plant. Further, we investigate the length of the insect mouthparts (beak) over time. Ongoing work has suggested that beak length may change across cohorts of developing insects in response to feeding deep within cactus fruit where seed and pulp depth decrease as the fruit ripens. Our results revealed a drop in cactus fruit abundance between the months of July through October 2015 as cactus fruits turned red and ripened. Simultaneously, the average body size of both males and females of N. femorata declined at two sampled sites. Male hind femora (a sexually-selected weapon) decreased disproportionately in size over time so that males later in the year had relatively smaller hind femora for their body size. The sex-specific patterns of morphological change led to increased sexual-size dimorphism and decreased sexual dimorphism for hind femora later in the year. Further, we found that beak length decreased across cohorts of insects as cactus fruit ripened, suggesting phenotypic plasticity in mouthpart length. Behavioral studies revealed that female readiness to mate increased as the season progressed. In sum, we found pronounced changes in the phenotypes of these insects in the field. Although this study is far from

  8. Resistance of Dusky Cotton Bug, Oxycarenus hyalinipennis Costa (Lygaidae: Hemiptera), to Conventional and Novel Chemistry Insecticides.

    Science.gov (United States)

    Ullah, Saif; Shad, Sarfraz Ali; Abbas, Naeem

    2016-02-01

    The dusky cotton bug, Oxycarenus hyalinipennis Costa (Lygaidae: Hemiptera), is polyphagous in nature and has become one of the severe sucking pests of cotton in Pakistan. O. hyalinipennis has the potential to develop resistance to a number of insecticides, and as a result, O. hyalinipennis outbreaks occur. There is no previous study from Pakistan regarding O. hyalinipennis resistance to insecticides. Therefore, the aim of this study was to assess the resistance of different field populations of O. hyalinipennis to conventional (bifenthrin, deltamethrin, lambda-cyhalothrin, profenofos, triazophos) and novel chemistry (emamectin benzoate, spinosad, chlorfenapyr, imidacloprid, and nitenpyram) insecticides. Five populations of O. hyalinipennis, collected from Multan, Khanewal, Muzaffargarh, Lodhran, and Bahawalpur, were tested for resistance to selected insecticides by the leaf dip method. For three pyrethroids, the resistance ratios were in the range of 14- to 30-fold for bifenthrin, 2.14- to 8.41-fold for deltamethrin, and 9.12- to 16-fold for lambda-cyhalothrin, compared with the laboratory susceptible strain (Lab-PK). For two organophosphates, the range of resistance ratios was 12- to 14-fold for profenofos and 9.04- to 15-fold for triazophos. For five novel chemistry insecticides, the range of resistance ratios was 4.68- to 9.83-fold for emamectin benzoate, 6.38- to 17-fold for spinosad, 16- to 46-fold for chlorfenapyr, 11- to 22-fold for imidacloprid, and 1.32- to 11-fold for nitenpyram. Regular assessment of resistance to insecticides and integrated management plans like judicious use of insecticides and rotation of insecticides along with different modes of action are required to delay resistance development in O. hyalinipennis.

  9. Sequencing and Characterization of the Invasive Sycamore Lace Bug Corythucha ciliata (Hemiptera: Tingidae) Transcriptome.

    Science.gov (United States)

    Li, Fengqi; Wang, Ran; Qu, Cheng; Fu, Ningning; Luo, Chen; Xu, Yihua

    2016-01-01

    The sycamore lace bug, Corythucha ciliata (Hemiptera: Tingidae), is an invasive forestry pest rapidly expanding in many countries. This pest poses a considerable threat to the urban forestry ecosystem, especially to Platanus spp. However, its molecular biology and biochemistry are poorly understood. This study reports the first C. ciliata transcriptome, encompassing three different life stages (Nymphs, adults female (AF) and adults male (AM)). In total, 26.53 GB of clean data and 60,879 unigenes were obtained from three RNA-seq libraries. These unigenes were annotated and classified by Nr (NCBI non-redundant protein sequences), Nt (NCBI non-redundant nucleotide sequences), Pfam (Protein family), KOG/COG (Clusters of Orthologous Groups of proteins), Swiss-Prot (A manually annotated and reviewed protein sequence database), and KO (KEGG Ortholog database). After all pairwise comparisons between these three different samples, a large number of differentially expressed genes were revealed. The dramatic differences in global gene expression profiles were found between distinct life stages (nymphs and AF, nymphs and AM) and sex difference (AF and AM), with some of the significantly differentially expressed genes (DEGs) being related to metamorphosis, digestion, immune and sex difference. The different express of unigenes were validated through quantitative Real-Time PCR (qRT-PCR) for 16 randomly selected unigenes. In addition, 17,462 potential simple sequence repeat molecular markers were identified in these transcriptome resources. These comprehensive C. ciliata transcriptomic information can be utilized to promote the development of environmentally friendly methodologies to disrupt the processes of metamorphosis, digestion, immune and sex differences.

  10. Experimental Infection of Rhodnius prolixus (Hemiptera, Triatominae with Mycobacterium leprae Indicates Potential for Leprosy Transmission.

    Directory of Open Access Journals (Sweden)

    Arthur da Silva Neumann

    Full Text Available Leprosy is a chronic dermato-neurological disease caused by infection with Mycobacterium leprae. In 2013 almost 200,000 new cases of leprosy were detected around the world. Since the first symptoms take from years to decades to appear, the total number of asymptomatic patients is impossible to predict. Although leprosy is one of the oldest records of human disease, the mechanisms involved with its transmission and epidemiology are still not completely understood. In the present work, we experimentally investigated the hypothesis that the mosquitoes Aedes aegypti and Culex quinquefasciatus and the hemiptera Rhodnius prolixus act as leprosy vectors. By means of real-time PCR quantification of M. leprae 16SrRNA, we found that M. leprae remained viable inside the digestive tract of Rhodnius prolixus for 20 days after oral infection. In contrast, in the gut of both mosquito species tested, we were not able to detect M. leprae RNA after a similar period of time. Inside the kissing bug Rhodnius prolixus digestive tract, M. leprae was initially restricted to the anterior midgut, but gradually moved towards the hindgut, in a time course reminiscent of the life cycle of Trypanosoma cruzi, a well-known pathogen transmitted by this insect. The maintenance of M. leprae infectivity inside the digestive tract of this kissing bug is further supported by successful mice footpad inoculation with feces collected 20 days after infection. We conclude that Rhodnius prolixus defecate infective M. leprae, justifying the evaluation of the presence of M. leprae among sylvatic and domestic kissing bugs in countries endemic for leprosy.

  11. Experimental Infection of Rhodnius prolixus (Hemiptera, Triatominae) with Mycobacterium leprae Indicates Potential for Leprosy Transmission

    Science.gov (United States)

    Neumann, Arthur da Silva; Dias, Felipe de Almeida; Ferreira, Jéssica da Silva; Fontes, Amanda Nogueira Brum; Rosa, Patricia Sammarco; Macedo, Rafael Enrique; Oliveira, José Henrique; Teixeira, Raquel Lima de Figueiredo; Pessolani, Maria Cristina Vidal; Moraes, Milton Ozório; Suffys, Philip Noel; Oliveira, Pedro L.; Sorgine, Marcos Henrique Ferreira; Lara, Flavio Alves

    2016-01-01

    Leprosy is a chronic dermato-neurological disease caused by infection with Mycobacterium leprae. In 2013 almost 200,000 new cases of leprosy were detected around the world. Since the first symptoms take from years to decades to appear, the total number of asymptomatic patients is impossible to predict. Although leprosy is one of the oldest records of human disease, the mechanisms involved with its transmission and epidemiology are still not completely understood. In the present work, we experimentally investigated the hypothesis that the mosquitoes Aedes aegypti and Culex quinquefasciatus and the hemiptera Rhodnius prolixus act as leprosy vectors. By means of real-time PCR quantification of M. leprae 16SrRNA, we found that M. leprae remained viable inside the digestive tract of Rhodnius prolixus for 20 days after oral infection. In contrast, in the gut of both mosquito species tested, we were not able to detect M. leprae RNA after a similar period of time. Inside the kissing bug Rhodnius prolixus digestive tract, M. leprae was initially restricted to the anterior midgut, but gradually moved towards the hindgut, in a time course reminiscent of the life cycle of Trypanosoma cruzi, a well-known pathogen transmitted by this insect. The maintenance of M. leprae infectivity inside the digestive tract of this kissing bug is further supported by successful mice footpad inoculation with feces collected 20 days after infection. We conclude that Rhodnius prolixus defecate infective M. leprae, justifying the evaluation of the presence of M. leprae among sylvatic and domestic kissing bugs in countries endemic for leprosy. PMID:27203082

  12. The biology and thermal requirements of the fennel aphid Hyadaphis foeniculi (Passerini (Hemiptera: Aphididae.

    Directory of Open Access Journals (Sweden)

    José B Malaquias

    Full Text Available The relationship between the insect development rate and temperature was established very early and represents an important ecological variable for modeling the population dynamics of insects. The accurate determination of thermal constant values and the lower and upper developmental thresholds of Hyadaphis foeniculi (Passerini (Hemiptera: Aphididae on fennel (Foeniculum vulgare Miller (Apiales: Apiaceae crops would obviously benefit the effective application of control measures. This paper is a study of the biology and thermal requirements of H. foeniculi. Winged insects were collected from fennel crops at the Embrapa Algodão in Campina Grande, Paraíba. Nymphs (age ≤24 h produced by winged insects were subjected to constant temperatures of 15, 20, 25, 28, 30 or 33°C, a photophase of 12 h and a relative humidity of 70±10%. The results of the study showed that at temperatures between 15 and 30°C, H. foeniculi nymphs were able to develop normally. The four instars were found at all temperatures tested. However, temperatures of 3 and 33°C were lethal to the nymphs. The nymph stage development time varied from 5 (30°C to 19 (15°C days. The influence of temperature on the development time is dependent on the instar. The base temperature (Tb and the thermal constant (K for the nymph stage were estimated at 11.2°C and 107.5 degree-days, respectively. The shortest nymph development stage was observed at 30°C, and the highest nymph viability (85.0% was observed at 28°C. This information can be used for developing phenological models based on the temperature and development rate relationships so that outbreaks of H. foeniculi in the fennel crop can be predicted, therefore improving the application of control programs targeting this fennel pest.

  13. Crop Loss Relationships and Economic Injury Levels for Ferrisia gilli (Hemiptera: Pseudococcidae) Infesting Pistachio in California.

    Science.gov (United States)

    Haviland, David R; Beede, Robert H; Daane, Kent M

    2015-12-01

    Ferrisia gilli Gullan (Hemiptera: Pseudococcidae) is a new pest in California pistachios, Pistacea vera L. We conducted a 3-yr field study to determine the type and amount of damage caused by F. gilli. Using pesticides, we established gradients of F. gilli densities in a commercial pistachio orchard near Tipton, CA, from 2005 to 2007. Each year, mealybug densities on pistachio clusters were recorded from May through September and cumulative mealybug-days were determined. At harvest time, nut yield per tree (5% dried weight) was determined, and subsamples of nuts were evaluated for market quality. Linear regression analysis of cumulative mealybug-days against fruit yield and nut quality measurements showed no relationships in 2005 and 2006, when mealybug densities were moderate. However, in 2007, when mealybug densities were very high, there was a negative correlation with yield (for every 1,000 mealybug-days, there was a decrease in total dry weight per tree of 0.105 kg) and percentage of split unstained nuts (for every 1,000 mealybug-days, there was a decrease in the percentage of split unstained of 0.560%), and a positive correlation between the percentage of closed kernel and closed blank nuts (for every 1,000 mealybug-days, there is an increase in the percentage of closed kernel and closed blank of 0.176 and 0.283%, respectively). The data were used to determine economic injury levels, showing that for each mealybug per cluster in May there was a 4.73% reduction in crop value associated with quality and a 0.866 kg reduction in yield per tree (4.75%).

  14. Identification of Aphis gossypii Glover (Hemiptera: Aphididae Biotypes from Different Host Plants in North China.

    Directory of Open Access Journals (Sweden)

    Li Wang

    Full Text Available The cotton-melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae, is a polyphagous species with a worldwide distribution and a variety of biotypes. North China is a traditional agricultural area with abundant winter and summer hosts of A. gossypii. While the life cycles of A. gossypii on different plants have been well studied, those of the biotypes of North China are still unclear.Host transfer experiments showed that A. gossypii from North China has two host-specialized biotypes: cotton and cucumber. Based on complete mitochondrial sequences, we identified a molecular marker with five single-nucleotide polymorphisms to distinguish the biotypes. Using this marker, a large-scale study of biotypes on primary winter and summer hosts was conducted. All A. gossypii collected from three primary hosts-hibiscus, pomegranate, and Chinese prickly ash-were cotton biotypes, with more cotton-melon aphids found on hibiscus than the other two species. In May, alate cotton and cucumber biotypes coexisted on cotton and cucumber seedlings, but each preferred its natal host. Both biotypes existed on zucchini, although the cucumber biotype was more numerous. Aphids on muskmelon were all cucumber biotypes, whereas most aphids on kidney bean were cotton biotypes. Aphids on seedlings of potato and cowpea belong to other species. In August, aphids on cotton and cucumber were the respective biotypes, with zucchini still hosting both biotypes as before. Thus, the biotypes had different fitnesses on different host plants.Two host-specialized biotypes (cotton and cucumber are present in North China. Hibiscus, pomegranate, and Chinese prickly ash can serve as winter hosts for the cotton biotype but not the cucumber biotype in North China. The fitnesses of the two host-specialized biotypes differ on various summer hosts. When alate aphids migrate to summer hosts, they cannot accurately land on the corresponding plant.

  15. Effects of thiamethoxam seed treatments on soybean aphid (Hemiptera: Aphididae) feeding behavior.

    Science.gov (United States)

    Stamm, M D; Heng-Moss, T M; Baxendale, F P; Reese, J C; Siegfried, B D; Hunt, T E; Gaussoin, R E; Blankenship, E E

    2013-12-01

    Since its discovery in North America in 2000, the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), has rapidly become an important pest of soybean [Glycine max (L.) Merrill], sometimes resulting in significant yield losses. Previous research has documented the toxicity of neonicotinoid seed treatments to soybean aphids, but control under field conditions has been inconsistent. Imidacloprid, a popular neonicotinoid insecticide, has been shown to exhibit antifeedant effects on aphids. Antifeedant activity has not been demonstrated for other neonicotinoids, including thiamethoxam. This research investigated the effects of a thiamethoxam seed treatment on soybean aphid feeding behavior by using electronic penetration graphs (EPG) to visualize stylet penetration behavior. Soybean aphid feeding behavior was assessed for 9 h on thiamethoxam-treated and untreated soybeans (V2 and V4 stages). Because results were inconclusive from initial experiments, a study was conducted to document the effects of thiamethoxam-treated soybeans on soybean aphid survival. The seed treatment was shown to negatively affect aphid survival at 4, 8, and 11 d after aphid introduction. A subsequent EPG study then was designed to document soybean aphid feeding behavior for 15 h, after an initial exposure of 9 h to thiamethoxam-treated soybeans. In this study, the exposed aphids exhibited significant differences in feeding behavior compared with those aphids feeding on untreated soybeans. Soybean aphids on thiamethoxam-treated soybeans spent significantly less time feeding in the sieve element phase, with a greater duration of nonprobing events. These studies suggest soybean aphids are unable to ingest phloem sap, which may be another important element in seed treatment protection.

  16. The biology and thermal requirements of the fennel aphid Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae).

    Science.gov (United States)

    Malaquias, José B; Ramalho, Francisco S; Lira, Aline C S; Oliveira, Flávia Q; Fernandes, Francisco S; Godoy, Wesley A C; Zanuncio, José C

    2014-01-01

    The relationship between the insect development rate and temperature was established very early and represents an important ecological variable for modeling the population dynamics of insects. The accurate determination of thermal constant values and the lower and upper developmental thresholds of Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae) on fennel (Foeniculum vulgare Miller (Apiales: Apiaceae)) crops would obviously benefit the effective application of control measures. This paper is a study of the biology and thermal requirements of H. foeniculi. Winged insects were collected from fennel crops at the Embrapa Algodão in Campina Grande, Paraíba. Nymphs (age ≤24 h) produced by winged insects were subjected to constant temperatures of 15, 20, 25, 28, 30 or 33°C, a photophase of 12 h and a relative humidity of 70±10%. The results of the study showed that at temperatures between 15 and 30°C, H. foeniculi nymphs were able to develop normally. The four instars were found at all temperatures tested. However, temperatures of 3 and 33°C were lethal to the nymphs. The nymph stage development time varied from 5 (30°C) to 19 (15°C) days. The influence of temperature on the development time is dependent on the instar. The base temperature (Tb) and the thermal constant (K) for the nymph stage were estimated at 11.2°C and 107.5 degree-days, respectively. The shortest nymph development stage was observed at 30°C, and the highest nymph viability (85.0%) was observed at 28°C. This information can be used for developing phenological models based on the temperature and development rate relationships so that outbreaks of H. foeniculi in the fennel crop can be predicted, therefore improving the application of control programs targeting this fennel pest.

  17. Methyl salicylate attracts natural enemies and reduces populations of soybean aphids (Hemiptera: Aphididae) in soybean agroecosystems.

    Science.gov (United States)

    Mallinger, Rachel E; Hogg, David B; Gratton, Claudio

    2011-02-01

    Methyl salicylate, an herbivore-induced plant volatile, has been shown to attract natural enemies and affect herbivore behavior. In this study, methyl salicylate was examined for its attractiveness to natural enemies of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), and for its direct effects on soybean aphid population growth rates. Methyl salicylate lures were deployed in plots within organic soybean [Glycine max (L.) Merr.] fields. Sticky card traps adjacent to and 1.5 m from the lure measured the relative abundance of natural enemies, and soybean aphid populations were monitored within treated and untreated plots. In addition, exclusion cage studies were conducted to determine methyl salicylate's effect on soybean aphid population growth rates in the absence of natural enemies. Significantly greater numbers of syrphid flies (Diptera: Syrphidae) and green lacewings (Neuroptera: Chrysopidae) were caught on traps adjacent to the methyl salicylate lure, but no differences in abundance were found at traps 1.5 m from the lure. Furthermore, abundance of soybean aphids was significantly lower in methyl salicylate-treated plots. In exclusion cage studies, soybean aphid numbers were significantly reduced on treated soybean plants when all plants were open to natural enemies. When plants were caged, however, soybean aphid numbers and population growth rates did not differ between treated and untreated plants suggesting no effect of methyl salicylate on soybean aphid reproduction and implicating the role of natural enemies in depressing aphid populations. Although aphid populations were reduced locally around methyl salicylate lures, larger scale studies are needed to assess the technology at the whole-field scale.

  18. Relationship of soybean aphid (Hemiptera: Aphididae) to soybean plant nutrients, landscape structure, and natural enemies.

    Science.gov (United States)

    Noma, Takuji; Gratton, Claudio; Colunga-Garcia, Manuel; Brewer, Michael J; Mueller, Emily E; Wyckhuys, Kris A G; Heimpel, George E; O'Neal, Matthew E

    2010-02-01

    In the north central United States, populations of the exotic soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), are highly variable across space, complicating effective aphid management. In this study we examined relationships of plant nutrients, landscape structure, and natural enemies with soybean aphid abundance across Iowa, Michigan, Minnesota, and Wisconsin, representing the range of conditions where soybean aphid outbreaks have occurred since its introduction. We sampled soybean aphid and its natural enemies, quantified vegetation land cover and measured soybean nutrients (potassium [K] and nitrogen [N]) in 26 soybean sites in 2005 and 2006. Multiple regression models found that aphid abundance was negatively associated with leaf K content in 2005, whereas it was negatively associated with habitat diversity (Simpson's index) and positively associated with leaf N content in 2006. These variables accounted for 25 and 27% of aphid variability in 2005 and 2006, respectively, suggesting that other sources of variability are also important. In addition, K content of soybean plants decreased with increasing prevalence of corn-soybean cropland in 2005, suggesting that landscapes that have a high intensification of agriculture (as indexed by increasing corn and soybean) are more likely to have higher aphid numbers. Soybean aphid natural enemies, 26 species of predators and parasitoids, was positively related to aphid abundance; however, enemy-to-aphid abundance ratios were inversely related to aphid density, suggesting that soybean aphids are able to escape control by resident natural enemies. Overall, soybean aphid abundance was most associated with soybean leaf chemistry and landscape heterogeneity. Agronomic options that can ameliorate K deficiency and maintaining heterogeneity in the landscape may reduce aphid risk.

  19. Biology and harmfulness of Planococcus vovae (Nassonov (Hemiptera: Pseudococcidae in Belgrade area

    Directory of Open Access Journals (Sweden)

    Draga Graora

    2014-03-01

    Full Text Available Planococcus vovae (Nassonov (Hemiptera: Pseudococcidae is an important pest on plants of the family Cupressaceae. Its numerous populations have been present in recent years on Juniperus spp. in Belgrade. Feeding by sap-sucking on all aboveground plant organs, it causes growth stagnation, chlorosis, drying of needles and branches, and even of entire plants under heavy infestation. Additionally, the scale excretes large quantities of honeydew, on which sooty mold develops, reducing photosynthesis and causing faster plant deterioration. Throughout 2007 and 2008, P. vovae was recorded on Juniperus spp. in 12 localities in Belgrade, and on Thuja sp. in a single locality. The pest was found to develop three generations per year and overwinter on branches at the egg or second instar stages. The first generation adults were observed at the end of May, the second generation at the beginning of August, while the third generation was recorded at the beginning of October. Different overwintering modes, and variable oviposition, embryonic and larval development periods led to an overlapping of generations and continuous presence of all developmental stages on plants. In different localities the infestation of plants varied in abundance from a few individual specimens to very large colonies. The highest infestation intensity was recorded in the localities Bežanija, Dorćol and Voždovac. The predatory species Chrysoperla carnea (Stephens (Neuroptera: Chrysopidae and Nephus bipunctatus (Kugelann (Coleoptera: Coccinelidae were found in the scale colonies. Regarding N. bipunctatus, this was its first record as a new species in the Serbian fauna.

  20. Mating disruption of Planococcus ficus (Hemiptera: Pseudococcidae) in vineyards using reservoir pheromone dispensers.

    Science.gov (United States)

    Cocco, Arturo; Lentini, Andrea; Serra, Giuseppe

    2014-10-15

    Mating disruption field experiments to control the vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), were carried out in 2008 and 2009 in two commercial vineyards in Sardinia (Italy). The effectiveness of mating disruption was evaluated by testing reservoir dispensers loaded with 100 mg (62.5 g/ha) and 150 mg (93.8 g/ha) of the sex pheromone in 2008 and 2009, respectively. The number of males captured in pheromone traps, the P. ficus population density and age structure, the parasitism rate, the percentage of ovipositing females, and the crop damage were compared between disrupted and untreated plots. In both field trials, the number of males captured in mating disruption plots was significantly reduced by 86% and 95%, respectively. Mating disruption at the initial dose of 62.5 g/ha of active ingredient gave inconclusive results, whereas the dose of 93.8 g/ha significantly lowered the mealybug density and modified the age structure, which showed a lower percentage of ovipositing females and a higher proportion of preovipositing females. Mating disruption did not affect negatively the parasitism rate, which was higher in the disrupted than in the control plots (>1.5-fold). Crop damage at harvest was very low in both field trials and did not differ between treatments. Mating disruption was effective in wide plots protected with dispensers loaded with 150 mg of the sex pheromone, showing its potential to be included in the overall integrated control programs in Mediterranean wine-growing regions.

  1. Comparison of sex pheromone traps for monitoring pink hibiscus mealybug (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Vitullo, Justin; Wang, Shifa; Zhang, Aijun; Mannion, Catharine; Bergh, J Christopher

    2007-04-01

    The pink hibiscus mealybug, Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae), is a highly polyphagous pest that invaded Florida in 2002 and has recently been reported from several locations in Louisiana. Although identification of its sex pheromone in 2004 improved monitoring capabilities tremendously, the effectiveness and efficiency of different pheromone trap designs for capturing males has not been evaluated. We deployed green Delta, Pherocon IlB, Pherocon V, Jackson, and Storgard Thinline traps in Homestead, FL, and compared the number of male M. hirsutus captured per trap, the number captured per unit of trapping surface area, the amount of extraneous material captured, and the time taken to count trapped mealybugs. Pheromone-baited traps with larger trapping surfaces (green Delta, Pherocon IIB, and Pherocon V) captured more males per trap than those with smaller surfaces (Jackson and Storgard Thinline), and fewest males were captured by Storgard Thinline traps. However, Jackson traps captured as many or more males per square centimeter of trapping surface as those with larger surfaces, and the time required to count males in Jackson traps was significantly less than in green Delta, Pherocon IIB, and Pherocon V traps. Although all trap designs accumulated some debris and nontarget insects, it was rated as light to moderate for all designs. Based on our measures of effectiveness and efficiency, the Jackson trap is most suitable for monitoring M. hirsutus populations. Additionally, unlike the other traps evaluated, which must be replaced entirely or inspected in the field and then redeployed, only the sticky liners of Jackson traps require replacement, enhancing the efficiency of trap servicing.

  2. Effect of temperature on the life history of the mealybug Paracoccus marginatus (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Amarasekare, Kaushalya G; Chong, Juang-Horng; Epsky, Nancy D; Mannion, Catharine M

    2008-12-01

    Effect of temperature on the life history of the mealybug Paracoccus marginatus Williams & Granara de Willink (Hemiptera: Pseudococcidae) was investigated in the laboratory. P. marginatus was able to develop and complete its life cycle at 18, 20, 25, and 30 +/- 1 degrees C. At 15, 34, and 35 degrees C, the eggs hatched after 27.5, 5.9, and 5.5 d of incubation, respectively, but further development of the first-instar nymphs was arrested. No eggs hatched at 37 degrees C. The developmental time for egg to adult was the longest at 18 degrees C for both males and females. Approximately 80-90% of the eggs survived between 20 and 30 degrees C. The highest fecundity was at 25 degrees C with each female producing an average of 300 eggs. Adult longevity, and preoviposition and oviposition periods increased with decreasing temperature up to 25 degrees C. The proportion of females was approximately 42% at 25 degrees C and was between 70 and 80% at 18, 20, and 30 degrees C. Adult males and females required 303.0 and 294.1 degree-days (DD), respectively, to complete their development. The estimated minimum temperature thresholds for the adult males and females were 14.5 and 13.9 degrees C, respectively. For adult males, the estimated optimum and maximum temperature thresholds were 28.7 and 31.9 degrees C; and for adult females, they were 28.4 and 32.1 degrees C, respectively. The ability of P. marginatus to develop, survive, and reproduce successfully between 18 and 30 degrees C suggests that it has the capability to develop and establish in areas within this temperature range.

  3. Pheromone-based mating disruption of Planococcus ficus (Hemiptera: Pseudococcidae) in California vineyards.

    Science.gov (United States)

    Walton, Vaughn M; Daane, Kent M; Bentley, Walter J; Millar, Jocelyn G; Larsen, Thomas E; Malakar-Kuenen, Raksha

    2006-08-01

    Experiments were conducted to test a mating disruption program for the mealybug Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) in California vineyards. The sprayable, microencapsulated formulation of the racemic sex pheromone lavandulyl senecioate was applied with an air-blast sprayer, using three and four applications in 2003 and 2004, respectively. Mating disruption was combined with an application of buprofezin (2004) in June. Compared with a no-pheromone control, there were significantly lower season-long trap catches of adult males, season-long mealybug densities (2003 only), and crop damage in mating disruption plots. The amount of mealybug reduction and mechanisms that resulted in lower crop damage in mating disruption plots is discussed. In samples taken during the growing season (April to September), mealybug density was only 12.0 +/- 15.6 and 31.1 +/- 11.6% lower in the mating disruption plots than in control plots in 2003 and 2004, respectively. In the mating disruption treatment, mealybug egg production was significantly lower (2003 only), as were the proportion of ovisacs and crawlers produced. There was no treatment impact on percentage of parasitism. Mealybug density influenced treatment impact. In 2004, vines were categorized as having low, medium, or high mealybug densities during a preapplication survey. After treatment application, mealybug density was reduced by 86.3 +/- 6.3% on vines in the low mealybug density category, but it was unchanged on vines in the high density category. Another factor that reduced treatment impact was the relatively short effective lifetime of the sprayable formulation.

  4. DNA barcoding of common soft scales (Hemiptera: Coccoidea: Coccidae) in China.

    Science.gov (United States)

    Wang, X-B; Deng, J; Zhang, J-T; Zhou, Q-S; Zhang, Y-Z; Wu, S-A

    2015-10-01

    The soft scales (Hemiptera: Coccoidea: Coccidae) are a group of sap-sucking plant parasites, many of which are notorious agricultural pests. The quarantine and economic importance of soft scales necessitates rapid and reliable identification of these taxa. Nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene (barcoding region) and 28S rDNA were generated from 340 individuals of 36 common soft scales in China. Distance-based [(best match, Automated Barcode Gap Discovery (ABGD)], tree-based (neighbor-joining, Bayesian inference), Klee diagrams, and general mixed Yule coalescent (GMYC) models were used to evaluate barcoding success rates in the data set. Best match showed that COI and 28S sequences could provide 100 and 95.52% correct identification, respectively. The average interspecific divergences were 19.81% for COI data and 20.38% for 28S data, and mean intraspecific divergences were 0.56 and 0.07%, respectively. For COI data, multiple methods (ABGD, Klee, and tree-based methods) resulted in general congruence with morphological identifications. However, GMYC analysis tended to provide more molecular operational taxonomic units (MOTUs). Twelve MOTUs derived from five morphospecies (Rhodococcus sariuoni, Pulvinaria vitis, Pulvinaria aurantii, Parasaissetia nigra, and Ceroplastes rubens) were observed using the GMYC approach. In addition, tree-based methods showed that 28S sequences could be used for species-level identification (except for Ceroplastes ceriferus - Ceroplastes pseudoceriferus), even with low genetic variation (<1%). This report demonstrates the robustness of DNA barcoding for species discrimination of soft scales with two molecular markers (COI and 28S) and provides a reliable barcode library and rapid diagnostic tool for common soft scales in China.

  5. Utilizing immunomarking techniques to track Halyomorpha halys (Hemiptera: Pentatomidae movement and distribution within a peach orchard

    Directory of Open Access Journals (Sweden)

    Brett R. Blaauw

    2016-05-01

    Full Text Available In this study we focus on the invasive brown marmorated stink bug, Halyomorpha halys (Stål (Hemiptera: Pentatomidae, which has a strong dispersal capacity and has had a significant impact on several cropping systems, including peach (Prunus persica (L.. Management of H. halys has relied on intensive insecticide use, and thus a better understanding of its dispersal behavior may assist in developing improved management strategies. In order to investigate H. halys movement and distribution patterns within a peach orchard we applied ecologically safe, food protein markers to the trees along the orchard border (chicken egg albumin in the form of liquid egg whites and to the trees within the orchard interior (bovine casein in the form of cow’s milk. We used enzyme-linked immunosorbent assays (ELISA to assess whether collected H. halys were “marked” with either of the two protein markers, revealing where in the orchard the bugs had visited. From the density data we determined that H. halys is a perimeter-driven pest in peaches, with a significantly higher density of bugs collected along the orchard border. Interestingly, this trend is primarily driven by the distribution of male bugs. The protein marking data revealed that a small proportion of male H. halys move equally between the orchard border and interior, while a small proportion of females move predominately to the border after visiting the interior. The verification of a strong edge-effect, although potentially sex-specific, implies that H. halys displays a dispersal behavior that may also be exploited for management, which may help growers more efficiently and more effectively manage H. halys.

  6. Lack of fitness costs associated with acetamiprid resistance in Bemisia tabaci (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Basit, Muhammad; Sayyed, Ali H; Saeed, Shafqat; Saleem, Mushtaq A

    2012-08-01

    Sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is a devastating pest that can cause severe damage to a range of crops by direct feeding and by plant virus transmission. Because of indiscriminate use of insecticides, this whitefly has developed resistance to several insecticides, including neonicotinoids. Our objectives were to determine fitness components affected by acetamiprid resistance in B. tabaci. Assay results showed that selection with acetamiprid had removed heterozygotes from the field population because the survival rate of the resistant population was significantly greater than that of the field population at a very high dose. Comparison of various life traits between the acetamiprid-selected (Aceta-SEL) population and three other populations showed that the numbers of eggs laid by acetamiprid Aceta-SEL population were significantly lower compared with that of other populations but that the proportions of eggs hatched were significantly higher. However, the time taken by nymphal stages of the Aceta-SEL population to develop was significantly higher than that of the susceptible populations. The intrinsic rate of increase, net reproductive rate, mean generation time, and doubling time of Aceta-SEL was significantly higher than Lab-PK and UNSEL populations, but the growth index was similar for all populations. The growth index and high intrinsic value of Aceta-SEL population suggest that the resistance allele may not have detrimental impact. The lack of fitness costs in B. tabaci could promote the rapid development of resistance to acetamiprid and other neonicotinoids. This resistance could threaten the sustainability of whitefly management program on genetically engineered cotton (Gossypium hirsutum L.) where neonicotinoids are being sprayed to manage sucking pests in the field.

  7. Seasonal Effects on the Population, Morphology and Reproductive Behavior of Narnia femorata (Hemiptera: Coreidae

    Directory of Open Access Journals (Sweden)

    Lauren A. Cirino

    2017-01-01

    Full Text Available Many insects are influenced by the phenology of their host plants. In North Central Florida, Narnia femorata (Hemiptera: Coreidae spends its entire life cycle living and feeding on Opuntia mesacantha ssp. lata. This cactus begins producing flower buds in April that lead to unripe green fruit in June that ripen into red fruit through December. Many morphological and behavioral characteristics of N. femorata are known to be affected by cactus phenology in a controlled laboratory setting, including the degree of sexual dimorphism and mating behavior. Our goal with this study was to determine if similar phenotypic changes of N. femorata occurred over time in the wild, and the extent to which these changes were concordant with phenological changes in its host plant. Further, we investigate the length of the insect mouthparts (beak over time. Ongoing work has suggested that beak length may change across cohorts of developing insects in response to feeding deep within cactus fruit where seed and pulp depth decrease as the fruit ripens. Our results revealed a drop in cactus fruit abundance between the months of July through October 2015 as cactus fruits turned red and ripened. Simultaneously, the average body size of both males and females of N. femorata declined at two sampled sites. Male hind femora (a sexually-selected weapon decreased disproportionately in size over time so that males later in the year had relatively smaller hind femora for their body size. The sex-specific patterns of morphological change led to increased sexual-size dimorphism and decreased sexual dimorphism for hind femora later in the year. Further, we found that beak length decreased across cohorts of insects as cactus fruit ripened, suggesting phenotypic plasticity in mouthpart length. Behavioral studies revealed that female readiness to mate increased as the season progressed. In sum, we found pronounced changes in the phenotypes of these insects in the field. Although this

  8. Characterization of Paecilomycescinnamomeus from the camellia whitefly, Aleurocanthus camelliae (Hemiptera: Aleyrodidae), infesting tea in Japan.

    Science.gov (United States)

    Saito, Tsutomu; Takatsuka, Jun; Shimazu, Mitsuaki

    2012-05-01

    The whitefly, Aleurocanthus camelliae Kanmiya and Kasai (Hemiptera: Aleyrodidae), is an invasive species in Japan that was first discovered in 2004 on tea in Kyoto. Soon after its arrival epizootics of an entomopathogenic fungus were observed in populations of the whitefly in many tea-growing regions. Here we identify this fungus as Paecilomyces cinnamomeus (Petch) Samson and W. Gams (Hypocreales: Clavicipitaceae) based on morphological characteristics and molecular analyses. This is the first record of P. cinnamomeus in Japan and also the first time it has been recorded from the genus Aleurocanthus. A isolate of P. cinnamomeus caused greater than 50% and 90% infection in whitefly nymphs at 1×10(6) and 1×10(7)conidia/ml respectively, while the commercial mycoinsecticides Preferd® (Isaria fumosorosea) and Mycotal® (Lecanicillium muscarium) caused <10% infection at their recommended field rates (5×10(6) and 9×10(6)conidia/ml, respectively), suggesting that P. cinnamomeus may be more useful as a control agent than the currently available mycoinsecticides. Optimum and upper limit temperatures for in vitro growth of P. cinnamomeus isolates were 22.5-25°C and 32.5°C, respectively. At field rates, the fungicide thiophanate-methyl caused some inhibition of in vitro growth of P. cinnamomeus isolates, and the bactericide copper oxychloride and the insecticides tolfenpyrad and methidathion were strongly inhibitory. The findings obtained in this study will be useful in the development of microbial control programs using P. cinnamomeus against A. camelliae.

  9. Ecology and management of the woolly whitefly (Hemiptera: Aleyrodidae), a new invasive citrus pest in Ethiopia.

    Science.gov (United States)

    Belay, Difabachew K; Zewdu, Abebe; Foster, John E

    2011-08-01

    Distribution and importance of woolly whitefly (Aleurothrixus floccosus) (Maskell) (Hemiptera: Aleyrodidae), was studied in Ethiopia with an evaluation of treatments against it. Results showed that the pest is distributed in most citrus-growing parts of the country equally infesting all types of citrus crops. Only one pupal parasitoid, Amitus sp., was recorded at Melkaoba. During 2006-2007, eight treatments gave better control of woolly whitefly compared with the control: endod (Phytolacca dodecandra L'Herit) berry extract, white oil 80%, neem oil, omo detergent soap, band application of gasoline, cyhalothrin (karate) 5% EC, selecron (profenofos) 500 EC, and rimon (novaluron) 10 EC. Treatments were applied on 6-8 yr-old orange trees at Melkaoba and Nazareth. At Melkaoba, application of cyhalothrin, selecron, white oil, and Neem gave better control of woolly whitefly compared with the control. All the treatments resulted in a lower number of ants than the control. Ants disrupt biocontrol agents of honeydew-secreting pests, including woolly whiteflies. Mean infestation score was higher in the control than the rest of the treatments. Similarly, at Nazareth, woolly whitefly numbers were lower recorded on cyhalothrin-treated plants. However, the numbers of eggs were significantly higher in endod extract-sprayed plants than the control. All treatments controlled ants better than the control except endod. Infestation scores were lower on endod- and cyhalothrin-treated plants than the control. Mean number of adult woolly whiteflies and eggs were significantly higher on newly grown leaves than older leaves. In general, the number of live adult woolly whiteflies showed a decreasing trend at both sites after treatment applications compared with the control.

  10. 阿维菌素与印楝油对柑桔红蜘蛛的增效作用%Synergistic Effect of Abamectin and Neem Oil Against Panonychus citri Me Gregor

    Institute of Scientific and Technical Information of China (English)

    熊忠华; 李保同; 熊件妹; 张纪利

    2012-01-01

    Toxicity of abamectin and neem oil against Panonychus citri and the synergistic effect of their mixture were evaluated in the lab. It was showed that, for the contact toxicity of abamectin and neem oil to adult famales of Panonychus citri, the LCX value was 0.01 jig/mL and 6 579.87 u.g/mL, respectively, after 24 h treatment. The optimal mixture ratio of abamectin with neem oil was determined by co-toxicity factor and eo-toxicity coefficient method. The results indicated that, among the 6 combinations of theses two active ingredients, the co-toxicity factor of combination at the ratios of 1 : 100 and 1 : 125 for abamectin vs neem oil was 24.50 and 31.08, respectively. Furthermore, combination at the ratio of 1 : 125 showed the highest synergism with a co-toxicity coefficient of 160.76.%室内测定阿维菌素与印楝油对柑桔红蜘蛛的毒力及其复配组合的联合作用.毒力测定结果表明,阿维菌素与印楝油对柑桔红蜘蛛雌成螨处理后24 h的LC50分别为0.01 μg/mL和6579.87 μg/mL.以共毒因子法评价阿维菌素与印楝油6种复配组合的联合作用,结果显示,二者以1∶100和1∶125两种比例复配对柑桔红蜘蛛雌成螨的共毒因子分别为24.50和31.08,具增效作用;进一步以共毒系数法确定阿维菌素与印楝油以1∶125的比例复配增效作用最为显著,共毒系数为160.76.

  11. Pheromone-baited traps for assessment of seasonal activity and population densities of mealybug species (Hemiptera: Pseudococcidae) in nurseries producing ornamental plants.

    Science.gov (United States)

    Waterworth, Rebeccah A; Redak, Richard A; Millar, Jocelyn G

    2011-04-01

    Operational parameters of traps baited with the pheromones of three mealybug species were optimized in nurseries producing ornamental plants. All pheromone doses (1-320 microg) attracted Pseudococcus longispinus (Targioni Tozzetti) and Pseudococcus viburni (Signoret) males, with the lowest dose (1 microg) attracting the fewest males for both species. Doses of 3.2-100 microg were as attractive to male P. longispinus as the highest dose (320 microg); doses from 10 to 320 microg were equally attractive for P. viburni males. Lures containing 25-microg doses of either pheromone had effective field lifetimes of at least 12 wk. Experiments were performed to test the efficacy of combining multiple pheromones to attract several species of mealybugs simultaneously. Lures loaded with a mixture of the pheromones of P. longispinus, P. viburni, and Planococcus citri (Risso) were as attractive to P. viburni and P. citri as lures with their individual pheromones. Response of P. longispinus to the blend was decreased by 38% compared with its pheromone as a single component. A subsequent trial with two-component blends showed that the pheromone ofP. citri was responsible for this modest decrease in P. longispinus response. This should not affect the overall efficacy of using these lures for monitoring the presence of all three mealybug species simultaneously. Pheromone traps were used to detect infestations of P. longispinus throughout the season and to track population cycles. When pheromone-baited traps for P. longispinus were compared with manual sampling, trap counts of male mealybugs were significantly correlated with mealybugs counted on plants in the vicinity of the traps.

  12. POPULATION FLUCTUATION OF Empoasca sp. (HEMIPTERA: CICADELLIDAE IN A PHYSIC NUT CROP IN MATO GROSSO DO SUL

    Directory of Open Access Journals (Sweden)

    Denisar Paggioli de Carvalho

    2015-11-01

    Full Text Available ABSTRACTPhysic nut (Jatropha curcas L. is an oilseed, semi-evergreen shrub or small tree of the Euphorbiaceae family, whose seeds contain oil that can be processed into a high quality biofuel. However, there have been reports of arthropods feeding from its leaves, including the green leafhopper Empoasca sp. (Hemiptera: Cicadellidae. The large numbers of this insect, observed in certain periods of the year in many regions of Brazil, are causing damage to the oilseed crops. This study aims at evaluating the fluctuation in green leafhopper population in a physic nut crop in Dourados, Mato Grosso do Sul, to assess possible correlations with rainfall, maximum, average and minimum temperatures. This evaluation was conducted between March 2011 and July 2012. The largest Empoasca sp. populations were recorded in May and June, 2011, and between February and May, 2012. No significant correlation was observed between the weather parameters analyzed and the fluctuation in the Hemiptera population, but there was a trend toward higher population density during the warmer and rainier months.RESUMENEl piñón manso (Jatropha curcas L. es una oleaginosa de la familia Euphorbiaceae que se destaca por la producción de semillas cuyo aceite tiene características deseables para la producción de biocombustibles. Sin embargo, hay informes de algunos artrópodos que usan la planta como fuente de alimento, incluyendo la cigarrita verde Empoasca sp. (Hemiptera: Cicadellidae. La alta incidencia de este insecto se comprueba en varias regiones del Brasil, en ciertas épocas del año, causando lesiones a esta oleaginosa. El objetivo de este estudio fue evaluar la fluctuación de la cigarrita verde en una plantación de piñón manso en Dourados, Mato Grosso do Sul, y la búsqueda de posibles correlaciones con las precipitaciones y las temperaturas máximas, medias y mínimas. Esta evaluación se realizó entre los meses de marzo 2011 hasta julio 2012. Poblaciones mayores

  13. First record of the leafhopper genus Sweta Viraktamath & Dietrich (Hemiptera, Cicadellidae,Typhlocybinae from China, with description of one new species feeding on bamboo

    Directory of Open Access Journals (Sweden)

    Lin Yang

    2012-04-01

    Full Text Available Sweta bambusana sp. n. (Hemiptera: Cicadellidae: Typhlocybinae: Dikraneurini, a new bamboo-feeding species, is described and illustrated from Guizhou and Guangdong of China. This represents the first record of the genus Sweta Viraktamath & Dietrich from China and the second known species of the genus. The new taxon extends the range of the genus Sweta, previously known only from northeast India and Thailand, considerably eastwards. A key for separation of the species of Sweta is given.

  14. Efektifitas Insektisida Nabati Lengkuas (Languas galangal L.) dan Serai (Andropogon nardus L.) dalam Mengendalikan Kepik Penghisap Polong Kedelai Riptortus linearis Fabr. (Hemiptera : Alydidae) di Rumah Kasa

    OpenAIRE

    Nainggolan, Shierly Parupa

    2016-01-01

    Shierly Parupa Nainggolan. 2015. “Effectivity of Botanical Insecticides Galanga (Alpinia galangal L.) and Lemon Grass (Andropogon nardus L.) against Soybean Pod Sucking Bugs (Riptortus linearis Fabr.) (Hemiptera : Alydidae) in Screen House“ supervised by Syahrial Oemry and Lisnawita. The objective of the research was to study the effectivity of botanical insecticides galangal and lemongrass to infect the adult soybean pod sucking bugs (Riptortus linearis Fabr.) in screen ...

  15. Primer registro de Acerophagus griseus (Hymenoptera: Encyrtidae como parasitoide de Pseudococcus viburni (Hemiptera: Pseudococcidae en el Alto Valle de Río Negro, Argentina

    Directory of Open Access Journals (Sweden)

    Daniel A. AQUINO

    2013-01-01

    Full Text Available Se cita por primera vez la presencia de Acerophagus griseus (De Santis (Hymenoptera: Encyrtidae como parasitoide de ninfas y adultos de Pseudococcus viburni (Signoret (Hemiptera: Pseudococcidae y se registra la zona de Alto Valle de Río Negro como nuevo registro de distribución en Argentina. Se brinda una diagnosis y se ilustran los caracteres morfológicos de A. griseus.

  16. Complete Genome Sequences of the Obligate Symbionts “Candidatus Sulcia muelleri” and “Ca. Nasuia deltocephalinicola” from the Pestiferous Leafhopper Macrosteles quadripunctulatus (Hemiptera: Cicadellidae)

    Science.gov (United States)

    Abbà, Simona; Kube, Michael; Marzachì, Cristina

    2016-01-01

    Two bacterial symbionts of the European pest leafhopper, Macrosteles quadripunctulatus (Hemiptera: Cicadellidae), were fully sequenced. “Candidatus Sulcia muelleri” and “Ca. Nasuia deltocephalinicola” represent two of the smallest known bacterial genomes at 190 kb and 112 kb, respectively. Genome sequences are nearly identical to strains reported from the closely related host species, M. quadrilineatus. PMID:26798106

  17. Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål (Hemiptera, Pentatomidae? A agressividade da presa altera o comportamento de ataque do predador Supputius cincticeps (Stål (Hemiptera, Pentatomidae?

    Directory of Open Access Journals (Sweden)

    Rafael Braga da Silva

    2012-06-01

    Full Text Available Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål (Hemiptera, Pentatomidae? The stink bug Supputius cincticeps (Stål (Hemiptera, Pentatomidae is a predator found in several Brazilian regions, which possesses desirable attributes as a natural control agent and in biological control programs. The aim of this study was to test if the attack behavior and predation success of S. cincticeps were affected by prey species. Larvae of Tenebrio molitor (L. (Coleoptera, Tenebrionidae, Spodoptera frugiperda (J. E. Smith (Lepidoptera, Noctuidae, and Thyrinteina arnobia (Stoll (Lepidoptera, Geometridae were offered to S. cincticeps in laboratory bioassays where predatory attack and prey defensive behaviors were observed for 2-hour periods. The attack behavior of S. cincticeps changed with the prey species offered. More than 25% of T. molitor and S. frugiperda larvae were immediately attacked, but T. arnobia was not immediately attacked by S. cincticeps. Successful attack (i.e., successful insertion of the predator stylets into the prey depends on the region of the body attacked, with a greater proportion of successful attacks in the anterior than in the median or posterior regions. Larvae of T. arnobia and S. frugiperda displayed a sequence of abrupt head and body movements in response to S. cincticeps attack. Attempts of predation were more successful on T. molitor and S. frugiperda than on T. arnobia. Information about the differential attack behavior of S. cincticeps on different prey species is important for designing successful biological control programs using this hemipteran predator.A agressividade da presa altera o comportamento de ataque do predador Supputius cincticeps (Stål (Hemiptera, Pentatomidae? O percevejo Supputius cincticeps (Stål (Hemiptera, Pentatomidae é um predador encontrado em várias regiões brasileiras, que possui atributos desejáveis como agente de controle natural ou em

  18. Hallazgo de Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae en el estado brasileño de "Rio Grande do Sul" Finding of Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae in the Brazilian State of "Rio Grande do Sul"

    Directory of Open Access Journals (Sweden)

    Roberto Salvatella

    1991-02-01

    Full Text Available Triatoma platensis Neiva 1913 (Hemiptera, Triatominae, especie ornitófila, con área de dispersión conocida en Argentina, Bolivia, Paraguay y Uruguay es notificada en un primer registro para Brasil. Hallada en el municipio de Uruguaiana (Río Grande do Sul en nidos de Anumbius annumbi (Vieillot, 1817 (Passeriformes, Furnariidae donde cohabitaba con cricétidos de la especie Orizomys flavescens. Ningún ejemplar de los siete colectados se presentó infectado por Trypanosoma cruzi.Triatoma platensis, an ornitophilic species, found in Argentina, Bolivia, Paraguay and Uruguay is reported for the first time in Brazil. It was found in the county of Uruguaiana (Rio Grande do Sul in nests of Anumbius annumbi (Vieillot, 1817 (Passeriformes, Furnariidae where it cohabited with cricetids belonging to the species Orizomys flavescens. None of the seven individuals collected were infected by Trypanosoma cruzi.

  19. First record of occurrence of mosca-negra-dos-citrus, Aleurocanthus woglumi Ashby, 1915 (Hemiptera: Sternorrhyncha: Aleyrodidae in Roraima, Brazil = Primeiro registro da ocorrência de mosca-negra-dos-citros, Aleurocanthus woglumi Ashby, 1915 (Hemiptera: Aleyrodidae em Roraima

    Directory of Open Access Journals (Sweden)

    Francisco Clemilto da Silva Maciel

    2011-12-01

    Full Text Available The Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae is an important pest of citrus. Originated in Asia, this pest was detected in Brazil for the first time in the State of Para, Brazil in 2001. In the culture of citrus fruits the black fly carries direct and indirect damage, impeding the development and production of plants. In addition to restricting trade in local areas from its occurrence to the presence of the plague, since the A. woglumi quarantine pest is considered present (A2 of high alert in accordance with Instruction No 23, April 29, 2008, established by the Ministério da Agricultura, Pecuária e Abastecimento of the Brazil. The objective of this paper was to record the first occurrence of Aleurocanthus woglumi in the State of Roraima, Brazil.= A mosca-negra-dos-citros, Aleurocanthus woglumi Ashb, (Hemiptera: Aleyrodidae é uma importante praga dos citros. De origem asiática, esta praga foi detectada no Brasil pela primeira vez no estado do Pará no ano de 2001. Na cultura dos citros a mosca-negra acarreta danos diretos e indiretos, prejudicando o desenvolvimento e produção das plantas. Além de restringir o comércio de locais de sua ocorrência para áreas livres da presença da praga, visto que o A. woglumi é considerado praga quarentenária presente (A2 de alerta máximo de acordo com a instrução normativa No 23, de 29 de abril de 2008; estabelecida pelo Ministério da Agricultura, Pecuária e Abastecimento. Objetivou-se com o presente trabalho registrar a primeira ocorrência de mosca-negra-dos-citros no estado de Roraima.

  20. Screening of Metarhizium anisopliae (Metsch. Sorok. strains against Mahanarva fimbriolata (Stal, 1854 (Hemiptera: Cercopidae/ Seleção de isolados de Metarhizium anisopliae (Metsch. Sorok. a Mahanarva fimbriolata (Stal, 1854 (Hemiptera: Cercopidae

    Directory of Open Access Journals (Sweden)

    Solange Aparecida Vieira

    2006-06-01

    Full Text Available The mechanized harvest of sugarcane results in accumulation of mulch on the soil and promotes favorable temperature and moist to development of sugarcane root spittlebug, Mahanarva fimbriolata (Stal, 1854 (Hemiptera: Cercopidae. High populations of this pest causes serious damages to plants and high costs with insecticides. This research work tested strains of Metarhizium anisopliae (Metsch. Sorok. pathogenic to sugarcane root spittlebug using a new methodology. The selection was carried out in laboratory conditions. Nymphs were sprayed with 2 mL of a suspension containing 5x107 conidia/mL and maintained in roots of sugarcane. The corrected mortality was evaluated five days after pulverization and ranged from 10.5 to 60% and the more pathogenic strains caused mortality from 46.5 to 59.7%.A colheita mecanizada de cana-de-açúcar, sem a queima da palhada, proporciona acúmulo de matériaorgânica no solo tornando o ambiente favorável ao desenvolvimento da cigarrinha-da-raiz, Mahanarva fimbriolata (Stal, 1854 (Hemiptera: Cercopidae. Em elevadas infestações essa praga tem causado prejuízos devido aos grandes danos nas plantas e aos gastos com agrotóxicos. O objetivo da pesquisa foi selecionar isolados de Metarhizium anisopliae (Metsch. Sorok. patogênicos para cigarrinha-da-raiz, usando uma nova metodologia. A seleção foi feita em condições de laboratório, utilizando-se ninfas coletadas a campo que foram pulverizadas com o fungo e mantidas em raiz de mudas de cana-de-açúcar. A mortalidade corrigida ao quinto dia após a inoculação variou de 10,5 a 60%, sendo que os isolados mais patogênicos causaram mortalidades de 46,5 a 59,7%.

  1. A new species of the genus Eurhadina Haupt (Hemiptera: Auchenorrhyncha: Cicadellidae: Typhlocybinae) from Korea, with a key to Korean species.

    Science.gov (United States)

    Oh, Sumin; Lim, Jongok; Jung, Sunghoon

    2016-01-01

    The leafhopper genus Eurhadina Haupt, 1929 belongs to the tribe Typhlocybini of subfamily Typhlocybinae (Hemiptera: Auchenorrhyncha: Cicadellidae). Currently, genus Eurhadina includes 3 subgenera, Eurhadina Haupt 1929, Singhardina Mahmood 1967, Zhihadina Yang & Li 1991. A total of 20 valid species of subgenus Eurhadina have been described in the Nearctic and Palaearctic region and the subgenus Singhardina includes 57 species in the Oriental and Palaearctic region (Huang & Zhang 1999, Dworakowska 2002). The subgenus Zhihadina includes only 1 species from China (Yang & Lee, 1991). So far, four species of subgenus Eurhadina were recorded in the Korean Peninsula (Kwon & Huh 2001): Eurhadina (Eurhadina) betularia Anufriev, 1969, E. (E.) koreana Dworakowska, 1971, E. (E.) pulchella (Fallen, 1806), and E. (E.) wagneri Dworakowska, 1969. The majority of species belonging to the subgenus Eurhadina are difficult to distinguish by external appearance because the color patterns of the forewings are very similar among species.

  2. First Findings in the Route of the Maize Bushy Stunt Phytoplasma Within Its Vector Dalbulus maidis (Hemiptera: Cicadellidae).

    Science.gov (United States)

    González, J García; Ossamu Tanaka, F A; Spotti Lopes, J R

    2016-04-01

    In the pathosystem of Dalbulus madis (DeLong & Wolcott) (Hemiptera: Cicadellidae), a vector of maize bushy stunt phytoplasma (MBSP), the interactions occurring during the passage, invasion, and multiplication of the phytoplasma inside the vector body have been generalized from other pathosystems, with a poor understanding of the specific interactions. With the aim to understand MBSP movement and potential specific interactions with its vector, D. maidis adults were dissected to obtain the intestine and salivary gland of both infected (acquisition access period=4 d; latent period=23 d) and noninfected individuals. The organs were processed for visualization with transmission electronic microscopy. Images of phytoplasma cells were observed in the alimentary canal, epithelium of the mesenteron, hemocele, and salivary gland of the vector, and were confirmed through observation of similar cells in maize roots with advanced disease symptoms. The study of the MBSP movement within its vector shows novel findings between the synergy of the MBSP phytoplasma and D. maidis.

  3. Three new species of mealybug (Hemiptera, Coccomorpha, Pseudococcidae) on persimmon fruit trees (Diospyros kaki) in southern Brazil.

    Science.gov (United States)

    Pacheco da Silva, Vitor C; Kaydan, Mehmet Bora; Germain, Jean-François; Malausa, Thibaut; Botton, Marcos

    2016-01-01

    Brazil has the greatest insect diversity in the world; however, little is known about its scale insect species (Hemiptera: Coccomorpha). Mealybugs (Pseudococcidae) have been found in at least 50% of persimmon orchards Diospyros kaki L. in the southern part of the country. In this study three new mealybug species on persimmon trees located in the Serra Gaúcha Region, RS, Brazil, namely, Anisococcus granarae Pacheco da Silva & Kaydan, sp. n., Ferrisia kaki Kaydan & Pacheco da Silva, sp. n. and Pseudococcus rosangelae Pacheco da Silva & Kaydan, sp. n. are described. In addition, an identification key for the genera occurring on fruit orchards and vineyards in Brazil is provided, together with illustrations and molecular data for the new species.

  4. Predation potential of Chilocorus cacti (Coleoptera: Coccinellidae) to the prickly pear cacti pest Dactylopius opuntiae (Hemiptera: Dactylopiidae).

    Science.gov (United States)

    Flores, A; Olvera, H; Rodríguez, S; Barranco, J

    2013-08-01

    Functional response of the predator Chilocorus cacti (Linnaeus) (Coleoptera: Coccinellidae) on five densities of Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae) female adults was assessed under laboratory conditions. The searching efficiency of C. cacti significantly decreased as prey density increased. The logistic regression for the predator had a negative and significant linear parameter indicating a type II functional response. Non-linear regression for Holling predator equation estimated a handling time of 1.79 ± 0.129 h and attack rate coefficient of 0.1003 ± 0.030. Most of this handling time was because the predator spent a lot of time removing the waxy coating that protects adult females of D. opuntiae. Chilocorus cacti consumes females of D. opuntiae in their reproductive stage; therefore, it could be an effective natural enemy to suppress or regulate low density populations of D. opuntiae, preventing them to reach high densities.

  5. First report of Lecanodiaspis dendrobii Douglas, 1892 (Hemiptera: Lecanodiaspididae and the associated parasitoid Cephaleta sp. (Hymenoptera: Pteromalidae in Brazil

    Directory of Open Access Journals (Sweden)

    A. L. Marsaro Júnior

    Full Text Available Abstract Lecanodiaspis dendrobii Douglas, 1892 (Hemiptera: Coccoidea: Lecanodiaspididae and the associated parasitoid Cephaleta sp. (Hymenoptera: Pteromalidae are reported for the first time in Brazil. Specimens of this scale insect were collected on branches and stems of Acacia mangium Willd., Leucaena leucocephala (Lam. de Wit (Fabaceae, Morus nigra L. (Moraceae, Citrus reticulata Blanco (Rutaceae, Tectona grandis L. f. (Verbenaceae, Anacardium occidentale (Anacardiaceae, Annona squamosa L. and Xylopia aromatica (Lam. Mart. (Annonaceae, in three municipalities of the Roraima state. All plants here mentioned are recorded for the first time as a host for L. dendrobii. Morphological characters of L. dendrobii and symptoms presented by the host plants infested by this pest are included in this work.

  6. Host plant preference of harlequin bug (Hemiptera: Pentatomidae), and evaluation of a trap cropping strategy for its control in collard.

    Science.gov (United States)

    Wallingford, Anna K; Kuhar, Thomas P; Pfeiffer, Douglas G; Tholl, Dorothea B; Freeman, Joshua H; Doughty, Hélène B; Schultz, Peter B

    2013-02-01

    Harlequin bug, Murgantia histrionica (Hahn) (Hemiptera: Pentatomidae), is a piercing-sucking pest of cole crops, causing cosmetic damage in low populations, while heavy pest pressure can kill plants or entire fields. Field studies were conducted to evaluate a trap crop for control of harlequin bug in collard. Field-cage choice tests found that potential trap crop plant species, mustard (Brassica juncea 'Southern Giant Curled'), rapeseed (B. napus 'Athena'), rapini (B. rapa), and arugula (Eruca satica) attracted more harlequin bugs than collard (B. oleracea 'Champion') and a nonbrassica control, bean (Phaseolus vulgaris'Bronco'). Mustard was the most consistently selected by harlequin bug over collard in choice tests, and was found to be an effective trap crop for reducing feeding injury on collard at two experimental sites. Augmentation of the mustard trap crop with a systemic, neonicotinoid insecticide provided no added control of harlequin bug for the 10 wk duration in the spring season.

  7. Morphology of the European species of the aphid genus Eulachnus (Hemiptera: Aphididae: Lachninae) - A SEM comparative and integrative study.

    Science.gov (United States)

    Kanturski, Mariusz; Karcz, Jagna; Wieczorek, Karina

    2015-09-01

    Scanning electron microscopy (SEM) methods were used for the first time to elucidate the external morphology of the European species of the genus Eulachnus (Hemiptera: Aphididae: Lachninae), a representative genus of the conifer-feeding aphids tribe Eulachnini. We examined and compared the external morphology of apterous and alate viviparous females from the parthenogenetic generation as well as oviparous females and alate males belonging to the sexual generation. FE-SEM images based on HMDS and cryo-SEM preparation techniques revealed better image quality than the CPD technique in regard to surface tension and morphological signs of cell deteriorations (i.e., existence of depressions, drying artifacts and membrane blebs). Three morphologically different species groups "agilis", "brevipilosus" and "cembrae" were proposed due to the differences in head, antennae, legs and dorsal chaetotaxy as well as dorsal sclerotization. The most characteristic features and differences of representatives of these groups are presented and discussed.

  8. Description of a new soft scale insect of the genus Pulvinaria Targioni Tozzetti (Hemiptera, Coccoidea, Coccidae from Bogota, Colombia

    Directory of Open Access Journals (Sweden)

    Hirotaka Tanaka

    2015-03-01

    Full Text Available A new soft scale (Hemiptera: Coccoidea: Coccidae species, Pulvinaria caballeroramosae Tanaka & Kondo, sp. n., is described from specimens collected on twigs of Ficus soatensis Dugand (Moraceae in Bogota, Colombia. The new species resembles P. drymiswinteri Kondo & Gullan, described from Chile on Drimys winteri J.R. Forst. & G. Forst. (Winteraceae, but differs in the distribution of preopercular pores on the dorsum, the presence of dorsal tubular ducts, dorsal microducts, and reticulation on the anal plates; and in its feeding habits, i.e., P. caballeroramosae feeds on the twigs whereas P. drymiswinteri feeds on the leaves of its host. A key to the Colombian species of Pulvinaria Targioni Tozzetti is provided.

  9. Nuclear rDNA-based molecular clock of the evolution of triatominae (Hemiptera: Reduviidae, vectors of Chagas disease

    Directory of Open Access Journals (Sweden)

    Bargues MD

    2000-01-01

    Full Text Available The evolutionary history and times of divergence of triatomine bug lineages are estimated from molecular clocks inferred from nucleotide sequences of the small subunit SSU (18S and the second internal transcribed spacer (ITS-2 of the nuclear ribosomal DNA of these reduviids. The 18S rDNA molecular clock rate in Triatominae, and Prosorrhynchan Hemiptera in general, appears to be of 1.8% per 100 million years (my. The ITS-2 molecular clock rate in Triatominae is estimated to be around 0.4-1% per 1 my, indicating that ITS-2 evolves 23-55 times faster than 18S rDNA. Inferred chronological data about the evolution of Triatominae fit well with current hypotheses on their evolutionary histories, but suggest reconsideration of the current taxonomy of North American species complexes.

  10. 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.

  11. Microwave-based Method for Genomic DNA Extraction and Rapid Detection Method from Xanthomonas axonopodis pv.citri%柑桔溃疡病菌基因组DNA的微波法抽提及快速检测

    Institute of Scientific and Technical Information of China (English)

    姚廷山; 周常勇; 胡军华; 冉春; 李鸿筠; 刘浩强; 肖田

    2012-01-01

    利用微波热震惊提取固体表面柑桔溃疡病基因组DNA并加以优化,所得到的基因组DNA可作为PCR反应的模板进行16SrDNA基因有效扩增.与柑桔溃疡病基园组DNA其他抽提方法相比较,微波法更适用于该病的快速检测,具有快速、筒便、费用低廉等特点,且对设备的要求不高,用特异性引物XCF/XCR可实现柑桔溃疡病菌的快速鉴定.%The optimized microwave extraction was conducted to attract the genome of citrus canker disease. The genome extraction method was fast,easy to handle with low cost The extracted DNA was suitable for PCR. The microwave-based method was suitable for fast identification compare to other methods. The method was effective, easy and fast, so it was recommended that the extraction method was applied for the detection of Xanthomonas oxonopodit pv. citri using primers XCF/XCR.

  12. Synergistic Effect of Three Substances on Paris polyphylla Smith against Panoychus citri McGregor%3种物质对七叶一枝花防治柑桔全爪螨的增效作用

    Institute of Scientific and Technical Information of China (English)

    周顺玉; 蒋春先; 杨群芳; 李庆

    2007-01-01

    研究了邻苯二酚、氮酮和硫酸钙3种化学物质对七叶一枝花(Paris polyphylla Smith)提取物防治柑桔全爪螨(Panoychus citri McGregor)的增效作用.结果表明:七叶一枝花乙醇、氯仿、乙酸乙酯提取物单用对柑桔全爪螨的致死中浓度(LC50)分别为1 588.537、1480.071、1 402.954 μg/ml;邻苯二酚对七叶一枝花乙醇、氯仿、乙酸乙酯提取物均有显著增效作用,LC50分别为284.506、582.295、897.323 μg/ml,分别增效5.6、2.5和1.6倍;氮酮仅对七叶一枝花乙醇提取物有增效作用,增效2.1倍;硫酸钙对七叶一枝花氯仿、乙酸乙酯提取物均有增效作用,分别增效1.4和2.1倍.

  13. 防治橘臀纹粉蚧药剂的室内筛选%Insecticide Screening for the control of Planococcus citri(Risso)(Homoptera: Pseudococcidae) in the laboratory

    Institute of Scientific and Technical Information of China (English)

    郭莹; 刘长明; 吴梅香; 杨广

    2012-01-01

    为有效地控制橘臀纹粉蚧Planococcus citri(Risso)发生,测定了6种农药在田间使用浓度下对该虫的致死效果.结果表明,在室内条件下,吡虫啉、烯啶虫胺、啶虫脒、阿维菌素和高效氯氰菊酯对1龄若虫的防治效果较好,用药后72 h校正死亡率均在80.0%以上,而杀扑磷仅74.8%.在防治应用中,建议推荐吡虫啉,烯啶虫胺,啶虫脒3种药剂,同时应针对不同虫态适当调整用药浓度和施药时间,以达到理想的防治效果.

  14. Investigation on Chelidonium citri attacking Murraya paniculata and its control%橘光绿天牛危害九里香绿化球调查及防治

    Institute of Scientific and Technical Information of China (English)

    刘有莲; 黄寿昌

    2003-01-01

    九里香绿化球受橘光绿天牛Chelidonium citri Grressitt为害3~4 a后,受害株率90.7%,枝枯株率74.1%,虫口密度2.11,危害度31.5%.危害造成枝枯形成空洞平均宽度为61 cm,占树冠平均周长的14.4%;枝枯形成空洞平均深度为68.4 cm,占平均树高50.8%.植株受害与方向的关系为:植株东向受害最多,占受害总株数30%;中部枝枯形成空洞平均宽度占树冠平均周长比率最大,为22.9%;西南方向枝枯形成空洞平均深度最深,占平均高度的90.9%.植株周围阴湿,虫口密度大.

  15. Comparison of Relative Bias, Precision, and Efficiency of Sampling Methods for Natural Enemies of Soybean Aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Bannerman, J A; Costamagna, A C; McCornack, B P; Ragsdale, D W

    2015-06-01

    Generalist natural enemies play an important role in controlling soybean aphid, Aphis glycines (Hemiptera: Aphididae), in North America. Several sampling methods are used to monitor natural enemy populations in soybean, but there has been little work investigating their relative bias, precision, and efficiency. We compare five sampling methods: quadrats, whole-plant counts, sweep-netting, walking transects, and yellow sticky cards to determine the most practical methods for sampling the three most prominent species, which included Harmonia axyridis (Pallas), Coccinella septempunctata L. (Coleoptera: Coccinellidae), and Orius insidiosus (Say) (Hemiptera: Anthocoridae). We show an important time by sampling method interaction indicated by diverging community similarities within and between sampling methods as the growing season progressed. Similarly, correlations between sampling methods for the three most abundant species over multiple time periods indicated differences in relative bias between sampling methods and suggests that bias is not consistent throughout the growing season, particularly for sticky cards and whole-plant samples. Furthermore, we show that sticky cards produce strongly biased capture rates relative to the other four sampling methods. Precision and efficiency differed between sampling methods and sticky cards produced the most precise (but highly biased) results for adult natural enemies, while walking transects and whole-plant counts were the most efficient methods for detecting coccinellids and O. insidiosus, respectively. Based on bias, precision, and efficiency considerations, the most practical sampling methods for monitoring in soybean include walking transects for coccinellid detection and whole-plant counts for detection of small predators like O. insidiosus. Sweep-netting and quadrat samples are also useful for some applications, when efficiency is not paramount.

  16. Nymphal and adult performance of Euschistus heros (Fabr.) (Hemiptera: Pentatomidae), as a potential alternative host for egg parasitoids multiplication

    Energy Technology Data Exchange (ETDEWEB)

    Peres, Wilsimar A.A. [Universidade Federal do Parana, Curitiba, PR (Brazil). Dept. de Zoologia; Correa-Ferreira, Beatriz S. [EMBRAPA, Londrina, PR (Brazil). Centro Nacional de Pesquisa de Soja

    2001-12-15

    This research aimed to evaluate the potential of Euschistus heros (Fabr.) (Hemiptera: Pentatomidae) as host for multiplication of egg parasitoids, by determining the nymphal and adult performance of E. heros from laboratory and the field, comparing with Nezara viridula (L.) (Hemiptera: Pentatomidae), under mass conditions. One hundred eggs of E. heros and N. viridula were placed among the leaves of soybean plants contained in cages (50x50x70 cm) and observation were made until adult emergence. The nymphs fed on soybean pods, dry soybean and peanuts seeds. The number of nymphs that reached adulthood and the development time were calculated. The survivorship and reproduction performance of laboratory and field populations of E. heros and N. viridula were evaluated during 13 weeks in February-May 1999. The number of eggs produced by 100 pairs of stink bugs per cage containing the same diet was recorded. Nymphal development time of E. heros and N. viridula was 33.0 and 34.0 days and 65.0% and 71.3% of nymphs reached adulthood, respectively. Adults of E. heros reared under laboratory conditions produced 2.5 times more eggs (5547.0 eggs/cage) than those collected in the field (2262.7 eggs/cage). The adult field population of E. heros had reduced reproduction and longevity due to parasitism by Hexacladia smithii Ash. (Hymenoptera: Encyrtidae). The N. viridula adults collected in the field produced 1.7 times more eggs (6304.9 eggs/cage) than those reared in the laboratory (3609.2 eggs/cage). E. heros laboratory reared is a promising host for egg parasitoids multiplication when compared with N. viridula collected in the field. (author)

  17. A new iranian species of Uroleucon Mordvilko, 1914 (Hemiptera, Aphididae from specimens in the Natural History Museum collection

    Directory of Open Access Journals (Sweden)

    Nieto Nafría, Juan M.

    2014-06-01

    Full Text Available Uroleucon (Uromelan helichrysi sp. n. (Hemiptera, Aphididae, Aphidinae: Macrosiphini is established from Iranian apterous and alate viviparous females caught on Helichrysum sp. (Asteraceae and preserved in the collection of the Natural History Museum (BMNH in London. The number of setae on the first tarsal segments (5, the number of caudal setae (20 to 28, the presence of abdominal marginal tubercles on abdominal segments 2 to 4, and the size of the cells of the siphuncular reticulation (relatively small allow the new species to be distinguished from other Palaeartic species of the subgenus Uromelan. Blackman and Eastop’s key to apterae on Helichrysum is modified to include the new species. urn:lsid:zoobank.org:pub:E2B89D59-05FD-4A9E-AD78-B3C302219A10Se establece la especie Uroleucon helichrysi n. sp. (Hemiptera: Aphididae: Aphidinae: Macrosiphini con la descripción de sus hembras vivíparas ápteras y aladas recogidas en Irán sobre Helichrysum sp. (Asteraceae, conservadas en la colección del Natural History Museum de Londres. La nueva especie se diferencia de otras especies paleárticas del subgénero Uromelan por la cantidad de setas en el primer segmento tarsal (5, la cantidad de setas caudales (20 a 28, por el tamaño de las celdillas de la reticulación cornicular (que son relativamente pequeñas y por la presencia de papilas marginales (presentes en los segmentos abdominales 2 a 4 Se incluye una modificación a la clave de Blackman and Eastop para las ápteras que viven sobre Helichrysum. urn:lsid:zoobank.org:pub:E2B89D59-05FD-4A9E-AD78-B3C302219A10

  18. Temperature-Dependent Fecundity and Life Table of the Fennel Aphid Hyadaphis foeniculi (Passerini (Hemiptera: Aphididae.

    Directory of Open Access Journals (Sweden)

    Francisco S Ramalho

    Full Text Available Hyadaphis foeniculi (Passerini (Hemiptera: Aphididae is a cosmopolitan species and the main pest of fennel in northeastern Brazil. Understanding the relationship between temperature variations and the population growth rates of H. foeniculi is essential to predict the population dynamics of this aphid in the fennel crop. The aim of this study was to measure the effect of constant temperature on the adult prereproductive period and the life table fertility parameters (infinitesimal increase ratio (rm, gross reproduction rate (GRR, net reproduction rate (R0, finite increase ratio (λ, generation time (GT, the time required for the population to double in the number of individuals (DT, and the reproduction value (RVx of the fennel pest H. foeniculi. The values of lx (survival of nymphs at age x increased as the temperature rose from 15 to 28°C and fell at 30°C, whereas mx (number of nymphs produced by each nymph of age x increased from 15 to 25°C and fell at 28 and 30°C. The net reproduction rates (R0 of populations of H. foeniculi increased with temperature and ranged from 1.9 at 15°C to 12.23 at 28°C for each generation. The highest population increase occurred with the apterous aphids at 28°C. The rate of population increase per unit time (rm (day ranged from 0.0033 (15°C to 0.1995 (28°C. The highest values of rm were recorded at temperatures of 28°C and 30°C. The rm values were a good fit to the models tested, with R2 > 0.91 and R2adj > 0.88. The models tested (Davidson, Sharpe and DeMichele modified by Schoolfield et al., Logan et al., Lamb, and Briere et al. were very good fits for the rm values observed, with R2 > 0.91 and R2adj > 0.88. The only exception was the Davidson model. Of the parameters studied, the reproductive capacity was higher in the apterous aphids, with the unique exception of daily fecundity at 28°C, which was higher in the alate aphids of H. foeniculi. Parameters relating to the age-specific fertility table for

  19. Inventory and assessment of foliar natural enemies of the soybean aphid (Hemiptera: Aphididae) in South Dakota.

    Science.gov (United States)

    Hesler, Louis S

    2014-06-01

    Soybean aphid (Aphis glycines Matsumura) (Hemiptera: Aphididae) is a major pest of soybean in northern production regions of North America, and insecticides have been the primary management approach while alternative methods are developed. Knowledge of arthropod natural enemies and their impact on soybean aphid is critical for developing biological control as a management tool. Soybean is a major field crop in South Dakota, but information about its natural enemies and their impact on soybean aphid is lacking. Thus, this study was conducted in field plots in eastern South Dakota during July and August of 2004 and 2005 to characterize foliar-dwelling, arthropod natural enemies of soybean aphid, and it used exclusion techniques to determine impact of natural enemies and ants (Hymenoptera: Formicidae) on soybean aphid densities. In open field plots, weekly soybean aphid densities reached a plateau of several hundred aphids per plant in 2004, and peaked at roughly 400 aphids per plant in 2005. Despite these densities, a relatively high frequency of aphid-infested plants lacked arthropod natural enemies. Lady beetles (Coleoptera: Coccinellidae) were most abundant, peaking at 90 and 52% of all natural enemies sampled in respective years, and Harmonia axyridis Pallas was the most abundant lady beetle. Green lacewings (Neuroptera: Chrysopidae) were abundant in 2005, due mainly to large numbers of their eggs. Abundances of arachnids and coccinellid larvae correlated with soybean aphid densities each year, and chrysopid egg abundance was correlated with aphid density in 2005. Three-week cage treatments of artificially infested soybean plants in 2004 showed that noncaged plants had fewer soybean aphids than caged plants, but abundance of soybean aphid did not differ among open cages and ones that provided partial or total exclusion of natural enemies. In 2005, plants within open cages had fewer soybean aphids than those within cages that excluded natural enemies, and aphid

  20. Temperature-Dependent Fecundity and Life Table of the Fennel Aphid Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae).

    Science.gov (United States)

    Ramalho, Francisco S; Malaquias, José B; Lira, Aline C S; Oliveira, Flávia Q; Zanuncio, José C; Fernandes, Francisco S

    2015-01-01

    Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae) is a cosmopolitan species and the main pest of fennel in northeastern Brazil. Understanding the relationship between temperature variations and the population growth rates of H. foeniculi is essential to predict the population dynamics of this aphid in the fennel crop. The aim of this study was to measure the effect of constant temperature on the adult prereproductive period and the life table fertility parameters (infinitesimal increase ratio (rm), gross reproduction rate (GRR), net reproduction rate (R0), finite increase ratio (λ), generation time (GT), the time required for the population to double in the number of individuals (DT), and the reproduction value (RVx)) of the fennel pest H. foeniculi. The values of lx (survival of nymphs at age x) increased as the temperature rose from 15 to 28°C and fell at 30°C, whereas mx (number of nymphs produced by each nymph of age x) increased from 15 to 25°C and fell at 28 and 30°C. The net reproduction rates (R0) of populations of H. foeniculi increased with temperature and ranged from 1.9 at 15°C to 12.23 at 28°C for each generation. The highest population increase occurred with the apterous aphids at 28°C. The rate of population increase per unit time (rm) (day) ranged from 0.0033 (15°C) to 0.1995 (28°C). The highest values of rm were recorded at temperatures of 28°C and 30°C. The rm values were a good fit to the models tested, with R2 > 0.91 and R2adj > 0.88. The models tested (Davidson, Sharpe and DeMichele modified by Schoolfield et al., Logan et al., Lamb, and Briere et al.) were very good fits for the rm values observed, with R2 > 0.91 and R2adj > 0.88. The only exception was the Davidson model. Of the parameters studied, the reproductive capacity was higher in the apterous aphids, with the unique exception of daily fecundity at 28°C, which was higher in the alate aphids of H. foeniculi. Parameters relating to the age-specific fertility table for H