Antifeedant activity of botanical crude extracts and their fractions on Bemisia tabaci (Homoptera: Aleyrodidae adults: II. Sechium pittieri (Cucurbitaceae

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Guillermo Flores

2008-12-01

Full Text Available Bemisia tabaci is a key pest of vegetables and other crops worldwide, but it is a particularly serious problem in the tropics, due to its ability to transmit several types of viruses, especially begomoviruses (Geminiviridae. Therefore, a preventive approach to deal with viral epidemics may be the deployment of repellents or phagodeterrents at earlier stages of plant development (critical period. Thus, the crude extract and four fractions thereof (water, water: methanol, methanol, and diethyl ether of wild "tacaco" (Sechium pittieri, Cucurbitaceae, were tested for phagodeterrence to B. tabaci adults under greenhouse conditions, on tomato plants, in Costa Rica. Both restricted-choice and unrestricted-choice experiments showed that the crude extract as well as some fractions exert such effect on the insect. In the former (in sleeve cages, fractions caused deterrence at doses as low as 0.1% (ether and 0.5% (water and water: methanol, with the methanol fraction showing no activity. However, in the latter (plants exposed in a greenhouse no one of the fractions performed well, suggesting that the deterrent principles somehow decomposed under the experimental conditions. Rev. Biol. Trop. 56 (4: 2115-2129. Epub 2008 December 12.Bemisia tabaci es una plaga clave de hortalizas y otros cultivos, mundialmente, y representa un problema particularmente serio en los trópicos, debido a su habilidad para transmitir varios tipos de virus, especialmente begomovirus (Geminiviridae. Por tanto, un enfoque preventivo para enfrentar las epidemias virales podría consistir en la utilización de sustancias repelentes o disuasivas en las eta-pas tempranas del desarrollo de la planta (período crítico. Así, el extracto crudo y cuatro fracciones (agua, agua: metanol, metanol, y éter dietílico de tacaco cimarrón (Sechium pittieri, Cucurbitaceae, fueron evaluadas por su posible actividad fagodisuasiva sobre B. tabaci en un invernadero, utilizando plantas de tomate, en

Antifeedant activity of botanical crude extracts and their fractions on Bemisia tabaci (Homoptera: Aleyrodidae adults: I. Gliricidia sepium (Fabaceae

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Guillermo Flores

2008-12-01

Full Text Available Bemisia tabaci is an important virus vector on a number of crops worldwide. Therefore, a preventive approach to deal with viral epidemics may be the deployment of repellents or phagodeterrents at earlier stages of plant development (critical period. Thus, the crude extract and four fractions thereof (water, water:methanol, methanol, and diethyl ether of mother-of-cocoa (Gliricidia sepium, Fabaceae were tested for phagodeterrence to B. tabaci adults under greenhouse conditions, on tomato plants, in Costa Rica. Both restricted-choice and unrestricted-choice experiments showed that the crude extract and some fractions exerted such effect on the insect. In the former (in sleeve cages, three fractions caused deterrence at doses as low as 0.1% (methanol, 0.5% (water:methanol and 1.5% (diethyl ether. However, in the latter (plants exposed in a greenhouse no one of the fractions performed well, suggesting that the deterrent principles somehow decomposed under the experimental conditions. Rev. Biol. Trop. 56 (4: 2099-2113. Epub 2008 December 12.Mundialmente, Bemisia tabaci es un importante vector de virus en numerosos cultivos. Por tanto, un enfoque preventivo para enfrentar las epidemias virales podría ser el empleo de sustancias repelentes o fagodisuasivas en las etapas tempranas del desarrollo de las plantas (período crítico. Así, tanto el extracto crudo como cuatro fracciones (agua, agua:metanol, metanol y éter dietílico del madero negro (Gliricidia sepium, Fabaceae fueron evaluadas en cuanto a su actividad fagodisuasiva sobre los adultos de B. tabaci en condiciones de invernadero, utilizando plantas de tomate, en Turrialba, Costa Rica. Tanto los experimentos de escogencia restringida como los de escogencia irrestricta revelaron que el extracto crudo y algunas fracciones mostraron dicha actividad. En los primeros experimentos (en jaulas de manga, tres fracciones causaron fagodisuasión a dosis tan bajas como 0.1% (metanol, 0.5% (agua:metanol y

Populations of predators and parasitoids of Bemisia tabaci (Hemiptera: Aleyrodidae) after the application of eight biorational insecticides in vegetable crops.

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Simmons, Alvin M; Shaaban, Abd-Rabou

2011-08-01

The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is an important pest of vegetables and many other crops worldwide. Eight biorational insecticides (based on oil, plant derivatives, insect growth regulator and fungus) were evaluated in the field for their influence on populations of six natural enemies of B. tabaci. Natural populations of two predators [Chrysoperla carnea Stephen (Neuroptera: Chrysopidae) and Orius spp. (Hemiptera: Anthocoridae)] and two genera of parasitoids [Encarsia spp. and Eretmocerus spp. (Hymenoptera: Aphelinidae)] were evaluated in eggplant (Solanum melongena L.). Also, augmented field populations of three predators [C. carnea, Coccinella undecimpunctata L. (Coleoptera: Coccinellidae) and Macrolophus caliginosus (Wagner) (Hemiptera: Miridae)] were evaluated in cabbage (Brassica oleracea var. capitata L.), cucumber (Cucumis sativus L.) and squash (Cucurbita pepo L.). Regardless of natural enemy or crop, jojoba oil, Biovar and Neemix had the least effect on abundance of the natural enemies in comparison with the other insecticides during a 14 day evaluation period. Conversely, Admiral, KZ oil, Mesrona oil, Mesrona oil + sulfur and natural oil had a high detrimental effect on abundance of the natural enemies. These results demonstrate the differential effects of biorational insecticides for whitefly control on predators and parasitoids in the field. This article is a US Government work and is in the public domain in the USA. Published 2011 by John Wiley & Sons, Ltd.

[Phagodeterrent activity of the plants Tithonia diversifolia and Montanoa hibiscifolia (Asteraceae) on adults of the pest insect Bemisia tabaci (Homoptera: Aleyrodidae)].

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Bagnarello, Gina; Hilje, Luko; Bagnarello, Vanessa; Cartín, Victor; Calvo, Marco

2009-12-01

Bemisia tabaci (Gennadius) is a polyphagous, cosmopolitan and worldwide relevant pest, mainly acting as a virus vector on many crops. A sound preventive approach to deal with it would be the application of repellent or deterrent substances hopefully present in tropical plants, which in turn may contribute to take advantage of the remarkable rich Mesoamerican biodiversity. Therefore, extracts of two wild plants belonging to family Asteraceae, titonia (Tithonia diversifolia) and "tora" (Montanoa hibiscifolia), were tested for phagodeterrence to B. tabaci adults. The crude leaf extract of each one, as well as four fractions thereof (hexane, dichlorometane, ethyl acetate, and methanol) were tested under greenhouse conditions; in addition, the extracts were submitted to a phytochemical screening to determine possible metabolites causing phagodeterrence. Both restricted-choice and unrestricted-choice experiments were conducted. In the former ones, each fraction was tested at four doses (0.1, 0.5, 1.0 and 1.5% v/v), which were compared with four control treatments: distilled water, endosulfan, an agricultural oil (Aceite Agricola 81 SC), and the emulsifier Citowett. Tomato plants were sprayed and placed inside sleeve cages, where 50 B. tabaci adults were released. The criterion to appraise phagodeterrence was the number of landed adults on plants at 48h. For the unrestricted-choice experiments, only the two highest doses (1.0 and 1.5%) of the crude extracts of each species were tested, and compared to distilled water and the agricultural oil. The titonia and "tora" crude extracts caused phagodeterrence, and for both plant species the methanol fraction stood out. Results suggest that metabolites causing phagodeterrence are several sesquiterpenic lactones, polyphenolic compounds (flavonoids and tannins) and saponins.

Compatibility of the insect pathogenic fungus Beauveria bassiana with neem against sweetpotato whitefly, Bemisia tabaci, on eggplant

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A study on the compatibility of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) with neem was conducted against sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on eggplant. Initially, three concentrations of B. bassiana (106, 1...

Susceptibility of MED-Q1 and MED-Q3 Biotypes of Bemisia tabaci (Hemiptera: Aleyrodidae) Populations to Essential and Seed Oils.

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Samuel Fogné, Drabo; Olivier, Gnankine; Bassolé, Imael H N; Nébié, Roger Charles; Laurence, Mouton

2017-06-01

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of many agricultural and ornamental crops in tropical and subtropical regions causing damages that result in important economic losses. Insecticides are commonly used in greenhouses or fields to control B. tabaci populations leading to rapid evolution of resistance that render treatments inefficient. Therefore, and for environmental and human health concerns, other approaches must be developed for this pest management. In the present study, we compare, using the leaf dip method, the toxicity of three essential oils (Cymbopogon citratus, Ocimum americanum, and Hyptis spicigera) and three seed oils (Lannea microcarpa, Lannea acida, and Carapa procera) with three chemical insecticides (acetamiprid, deltamethrin, and chlorpyrifos-ethyl) on adults. Two B. tabaci biotypes (MED-Q1 and MED-Q3) belonging to the Mediterranean species and collected in Burkina Faso were used. Essential oils were analyzed by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. We showed that these two biotypes have different levels of resistance to the three insecticides, MED-Q3 being more sensitive than MED-Q1. Moreover, they differ in the frequency of resistance alleles to insecticides, especially for organophosphates, as these alleles are almost fixed in MED-Q1. On the other hand, the two biotypes prove to be more susceptible to the plant extracts than to insecticides except for chlorpyrifos-ethyl, with essential oils that showed the highest insecticidal activities. Monoterpenes content were the most abundant and showed the highest insecticidal activities. Our results indicated that essential oils, but also seed oils, have the potential to constitute an alternative strategy of pest management. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Biología de Eretmocerus mundus (Hymenoptera: Aphelinidae, parasitoide del complejo Bemisia tabaci (Homoptera: Aleyrodidae, en condiciones de laboratorio

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Yerlin CHACÓN CASTRO

2010-01-01

Full Text Available La estimación de los atributos biológicos de un enemigo natural, previa a su empleo en el campo, constituye un aspecto de importancia en todo proyecto de control biológico. El objetivo de este trabajo fue evaluar los principales parámetros biológicos de Eretmocerus mundus Mercet, parasitoide de Bemisia tabaci (Gennadius, bajo condiciones de laboratorio. La emergencia del adulto, longevidad y fecundidad de la hembra, proporción sexual de la descendencia, tasa intrínseca de crecimiento poblacional (r m , tasa neta de reproducción (R o y tiempo generacional (T; se estimaron mediante la técnica de tabla de vida y fecundidad, utilizando el pimiento ( Capsicum annuum L. y el tomate ( Solanum lycopersicum L. como plantas hospederas. Los resultados obtenidos en pimiento y tomate fueron respectivamente: supervivencia pupal: 86.86 ± 1.94 y 83,45 ± 2,13%; longevidad de la hembra: 18,19 ± 1,61 y 17,00 ± 0,92 días; proporción sexual: 0,34 ± 0,06 y 0,47 ± 0,05 hembras/(machos + hembras; l x50 : 21 y 18 días; r m : 0,226 ± 0,061 y 0,228 ± 0,057 ninfas parasitadas/hembra/día; Ro: 189,71 ± 24,25 y 154,65 ± 17,58 ninfas parasitadas/hembra; T: 25,88 ± 0,42 y 24,03 ± 0,34 días. Los resultados obtenidos son una contribución al conocimiento de la población local del parasitoide y su posible papel como agente de control biológico de B. tabaci.

Identifikasi kutukebul (Hemiptera: Aleyrodidae dari beberapa tanaman inang dan perkembangan populasinya

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Purnama Hidayat

2017-02-01

Full Text Available Whiteflies (Hemiptera: Aleyrodidae can cause direct and indirect damages on plants, especially vegetables. There is only limited information regarding taxonomy and population dynamic of whiteflies attacking vegetables in Indonesia. This research is conducted to identify species of whitefly collected from chili pepper, tomato, and soybean, and to study their population dynamic. The information gathered from these studies will be useful to support whitefly management in the field. Based on morphology identification of the puparium collected directly from the host plants, there were four species of whitefly identified from chili pepper, tomato, and soybean in Bogor, Cianjur, and Sukabumi, i.e. Bemisia tabaci, Aleurodicus dispersus, Trialeurodes vaporariorum, and Dialeurodes sp. The presence of B. tabaci on chili pepper and tomato was associated with virus infection that causes yellowing and leaf curl disease. This population of B. tabaci tended to increase along with plant growth and generally reached the highest population when the plant was 60-70 days after planting.

Prey Preference of Predatory mite Amblyseius swirskii (Athias-Henriot (Acari: Phytoseiidae on untreated and Beauveria bassiana-treated of Trialeurodes vaporariorum (Homoptera: Aleyrodidae

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Marjan Seiedy

2018-01-01

Full Text Available Introduction The predator Amblyseius swirskii and entomopathogenic fungus Beauveria bassiana are important biocontrol agents of Trialeurodes vaporariorum. Determination of the host preference of predators in the fields when receiving signals related to either untreated and Beauveria bassiana-treated pest is important. Materials and Methods In this research, the prey preference of adult female (2 days old of A. swirskii was determined on untreated and Beauveria bassiana-treated of Trialeurodes vaporariorum (Homoptera: Aleyrodidae in various treatments base on Manly Index. These different treatments consisted of two time intervals; 24 and 48 h post-inoculation of greenhouse whiteflies with 1×105 conidia /ml of B. bassiana with 13 replicates. 24-h starved predators were added to the leaf discs singly then the number of consumed untreated and B. bassiana-treated T. vaporariorum in each Petri dish was assessed after 24 h. Results and Discussion The results revealed that mean number of consumed B. bassiana-treated T. vaporariorum in two time intervals; 24 and 48 h. after inoculation were 4/15±0/19 and 2.23±0/12, respectively. This investigation showed a significant preference of A. swirskii towards untreated T. vaporariorum in 24 (P< 0.0034 and 48 h. (P

Insecticide resistance in Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) and Anopheles gambiae Giles (Diptera: Culicidae) could compromise the sustainability of malaria vector control strategies in West Africa.

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Gnankiné, Olivier; Bassolé, Imael H N; Chandre, Fabrice; Glitho, Isabelle; Akogbeto, Martin; Dabiré, Roch K; Martin, Thibaud

2013-10-01

Insecticides from the organophosphate (OP) and pyrethroid (PY) chemical families, have respectively, been in use for 50 and 30 years in West Africa, mainly against agricultural pests, but also against vectors of human disease. The selection pressure, with practically the same molecules year after year (mainly on cotton), has caused insecticide resistance in pest populations such as Bemisia tabaci, vector of harmful phytoviruses on vegetables. The evolution toward insecticide resistance in malaria vectors such as Anopheles gambiae sensus lato (s.l.) is probably related to the current use of these insecticides in agriculture. Thus, successful pest and vector control in West Africa requires an investigation of insect susceptibility, in relation to the identification of species and sub species, such as molecular forms or biotypes. Identification of knock down resistance (kdr) and acetylcholinesterase gene (Ace1) mutations modifying insecticide targets in individual insects and measure of enzymes activity typically involved in insecticide metabolism (oxidase, esterase and glutathion-S-transferase) are indispensable in understanding the mechanisms of resistance. Insecticide resistance is a good example in which genotype-phenotype links have been made successfully. Insecticides used in agriculture continue to select new resistant populations of B. tabaci that could be from different biotype vectors of plant viruses. As well, the evolution of insecticide resistance in An. gambiae threatens the management of malaria vectors in West Africa. It raises the question of priority in the use of insecticides in health and/or agriculture, and more generally, the question of sustainability of crop protection and vector control strategies in the region. Here, we review the susceptibility tests, biochemical and molecular assays data for B. tabaci, a major pest in cotton and vegetable crops, and An. gambiae, main vector of malaria. The data reviewed was collected in Benin and Burkina

Genome-Wide Characterization and Expression Profiling of Sugar Transporter Family in the Whitefly, Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae

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Zezhong Yang

2017-05-01

Full Text Available Sugar transporters (STs play pivotal roles in the growth, development, and stress responses of phloem-sucking insects, such as the whitefly, Bemisia tabaci. In this study, 137 sugar transporters (STs were identified based on analysis of the genome and transcriptome of B. tabaci MEAM1. B. tabaci MEAM1 encodes a larger number of STs than other selected insects. Phylogenetic and molecular evolution analysis showed that the 137 STs formed three expanded clades and that the genes in Sternorrhyncha expanded clades had accelerated rates of evolution. B. tabaci sugar transporters (BTSTs were divided into three groups based on their expression profiles across developmental stages; however, no host-specific BTST was found in B. tabaci fed on different host plants. Feeding of B. tabaci adults with feeding diet containing dsRNA significantly reduced the transcript level of the target genes in B. tabaci and mortality was significantly improved in B. tabaci fed on dsRNA compared to the control, which indicates the sugar transporters may be used as potential RNAi targets for B. tabaci bio-control. These results provide a foundation for further studies of STs in B. tabaci.

Preferência de Bemisia tabaci biótipo B em linhagens mutantes de algodoeiro Bemisia tabaci biotype B preference in mutant cotton lines

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Francisco das Chagas Vidal Neto

2008-02-01

Full Text Available Os efeitos de caracteres mutantes morfológicos do algodoeiro (Gossypium hirsutum L. r. latifolium Hutch.: folha okra, bráctea frego e planta vermelha, em relação à resistência à mosca-branca (Bemisia tabaci biótipo B Hemiptera: Aleyrodidae, foram avaliados em experimentos com ou sem chance de escolha. Os experimentos foram conduzidos em casa-de-vegetação, no delineamento de blocos ao acaso, em fatorial 23 + 1, com quatro repetições. O mutante com a característica planta vermelha foi menos atrativo e menos preferido para oviposição, em relação à planta verde, em ambos os ensaios, com ou sem escolha. Não houve preferência quanto à forma da folha e ao tipo de bráctea.The effects of cotton lines (Gossypium hirsutum L. r. latifolium Hutch. with mutants morphologic characteristics: okra leaf, frego bract and red plant in relation to host plant resistance to whitefly (Bemisia tabaci bioyipe B Hemiptera: Aleyrodidae, were evaluated in choice or no choice assays. The assays were carried out in the greenhouse conditions, according to a completely randomized block design, in a 23 + 1 in a factorial arrangement with four replications. The mutant with red plant characteristic was less attractive and less preferred for oviposition than the normal green plant does, in both, whit or without choice tests. It did not have preference in relation to the form of the leaf and bract type.

Detection of resistance, cross-resistance, and stability of resistance to new chemistry insecticides in Bemisia tabaci (Homoptera: Aleyrodidae).

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Basit, Muhammad; Saeed, Shafqat; Saleem, Mushtaq Ahmad; Denholm, Ian; Shah, Maqbool

2013-06-01

Resistance levels in whitefly, Bemisia tabaci (Gennadius) collections from cotton and sunflower (up to four districts) for five neonicotinoids and two insect growth regulators (IGRs) were investigated for two consecutive years. Based on the LC50(s), all collections showed slight to moderate levels of resistance for the tested insecticides compared with the laboratory susceptible population. The data also indicated that cotton and sunflower collections had similar resistance levels. In comparison (four collections), Vehari collections showed higher resistance for acetamiprid, thiacloprid, and nitenpyram compared with those of others. Average resistance ratios for acetamiprid, thiacloprid, and nitenpyram ranged from 5- to 13-, 4- to 8-, and 9- to 13-fold, respectively. Multan and Vehari collections also exhibited moderate levels (9- to 16-fold) of resistance to buprofezin. Furthermore, toxicity of neonicotinoids against immature stages was equal to that of insect growth regulators. The data also suggested that resistance in the field populations was stable. After selection for four generations with bifenthrin (G1 to G4), resistance to bifenthrin increased to 14-fold compared with the laboratory susceptible population. Selection also increased resistance to fenpropathrin, lambdacyhalothrin, imidacloprid, acetamiprid, and diafenthuron. Cross-resistance and stability of resistance in the field populations is of some concern. Rotation of insecticides having no cross-resistance and targeting the control against immature stages may control the resistant insects, simultaneously reducing the selection pressure imposed.

Factors affecting population dynamics of maternally transmitted endosymbionts in Bemisia tabaci.

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Huipeng Pan

Full Text Available While every individual of Bemisia tabaci (Hemiptera: Aleyrodidae harbors the primary symbiont (P-symbiont Portiera, the infection frequencies of the six secondary symbionts (S-symbionts including Hamiltonella, Arsenophonus, Cardinium, Wolbachia, Rickettsia and Fritschea vary greatly among different populations. To characterize the factors influencing the infection dynamics of the six S-symbionts in B. tabaci, gene-specific PCR were conducted to screen for the presence of the P-symbiont Portiera and the six S-symbionts in 61 (17 B and 44 Q biotypes field populations collected from different plant species and locations in China. All individuals of the 61 populations hosted the P-symbiont Portiera, but none of them harbored Arsenophonus and Fritschea. The presence and infection rates of Hamiltonella, Cardinium, Rickettsia, Wolbachia and their co-infections Rickettsia + Hamiltonella (RH, Rickettsia + Cardinium (RC, Hamiltonella + Cardinium (HC and Rickettsia + Hamiltonella + Cardinium (RHC varied significantly among the 61 field populations; and the observed variations can be explained by biotypes, sexes, host plants and geographical locations of these field populations. Taken together, at least three factors including biotype, host plant and geographical location affect the infection dynamics of S-symbionts in B. tabaci.

RESULTS OF THE THREE-YEAR MONITORING (2001.-2003. OF TOBACCO WHITEFLY Bemisia tabaci (Gennadius, 1889, (HOMOPTERA: ALEYRODIDAE IN CROATIA

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Tatjana Masten

2004-06-01

Full Text Available The quarantine pest tobacco whitefly Bemisia tabaci (Gennadius, 1889 was for the first time found in Croatia in 2000 on some culture and weed plants in greenhouses and in the open field in the area from Trogir to Omiš. Monitoring of tobacco whitefly was organized in all counties (21. Eventual presence of tobacco whitefly adults on the plants in glasshouses was established by the hanging of yellow sticky traps. In the course of monitoring the undersides of leaves on host plants were inspected for the purpose of discovering pest nymphal and pupal stages. The plants of poinsettia (Euphorbia pulcherrima produced as pest free plants have been used as catch plants in the conditions of lower infestation of host plants by tobacco whitefly adults. In three-year monitoring it was found out that poinsettia is the most atractive host plant for this pest between 38 host plants being registered during this monitoring. The fact that tobacco whitefly during the summer was found on the vegetables, ornamentals and weeds in the open fields in Dalmatia indicate that tobacco whitefly became domesticated and it can successfully overwinter in mediteranean climate conditions. During the monitoring tobacco whitefly was detected in 13 counties in our country, indicating shows that tobacco whitefly has been spreading progresivly since it was found in Croatia for the first time.

Characterization of Antixenosis in Soybean Genotypes to Bemisia tabaci (Hemiptera: Aleyrodidae) Biotype B.

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Baldin, E L L; Cruz, P L; Morando, R; Silva, I F; Bentivenha, J P F; Tozin, L R S; Rodrigues, T M

2017-08-01

Bemisia tabaci biotype B (Gennadius) is one of the most important soybean pest worldwide. Herein, 15 soybean genotypes were evaluated, to characterize the occurrence of antixenosis to B. tabaci biotype B. Initially, a multiple-choice test with all genotypes was carried out, evaluating the settling and oviposition preference at 3 d after infestation, and the colonization by nymphs after 48 d of infestation. Subsequently, a no-choice test, using 14 genotypes, was conducted with infested plants individually, and the number of eggs was counted after 72 h. Then, 10 genotypes were selected (indicative of resistance and susceptibility), which were evaluated for whitefly settling 24, 48, and 72 h after infestation and for oviposition 72 h after infestation. The trichomes of the leaflets were characterized for density, size, and inclination to establish possible correlations with the settling and oviposition in the genotypes. In the first multiple-choice test, involving 15 genotypes, 'IAC-17,' 'IAC-19,' and UX-2569-159 expressed antixenosis against B. tabaci. 'Jackson,' 'P98Y11,' and PI-229358 exhibited the same behavior in the no-choice test. In the multiple-choice test, 'Jackson,' 'P98Y11,' and 'TMG1176 RR' were the least attractive and least used for oviposition. The antixenosis shown by 'Jackson,' 'P98Y11,' and PI-229358 may be related to the characteristics of the trichomes (lower density and inclined). Based on the experiments carried out, 'IAC-17,' 'IAC-19,' 'Jackson,' 'P98Y11,' PI-229358, TMG1176 RR, and UX-2569-159 are considered promising for resistance to B. tabaci biotype B and may be exploited in soybean breeding programs for resistance to insects. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Densidades y frecuencias de liberación de Encarsia formosa (Hymenoptera: Aphelinidae sobre Trialeurodes vaporariorum (Homoptera: Aleyrodidae en tomate

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Tello Paola

2007-12-01

Full Text Available

La mosca blanca de los invernaderos, Trialeurodes vaporariorum (Westwood (Homoptera: Aleyrodidae es una de las plagas más importantes de cultivos de tomate bajo invernadero en la Sabana de Bogotá. Para su control tradicionalmente se acude a la aplicación de insecticidas. Sin embargo, también son contempladas liberaciones del parasitoide Encarsia formosa (Gahan (Hymenoptera: Aphelinidae. Para estandarizar el proceso de cría masiva de E. formosa, se evaluaron tres densidades diferentes de liberación de las avispas (6, 12 y 18 avispas/planta en tres frecuencias de liberación (1, 2 y 3 veces/semana, sobre plantas de tomate de ocho semanas de edad con tres niveles de infestación (15, 30 y 45 ninfas de mosca blanca/hoja, susceptibles de ser parasitadas. El mayor porcentaje de parasitismo (70% en ninfas de tercer instar se logró cuando se liberaron seis avispas por planta, dosificadas en tres momentos diferentes en la misma semana. El menor porcentaje de parasitismo (50%, se obtuvo cuando se realizó una sola liberación de 6, 12 o 18 avispas. Los resultados anteriores permiten concluir que se puede lograr un porcentaje de parasitismo en torno a un 70% de la infestación de mosca blanca (hasta 45 ninfas/hoja en plantas de tomate con pocas avispas de E. formosa (seis cuando se liberan en tres momentos diferentes.

Two cytochrome P450 genes are involved in imidacloprid resistance in field populations of the whitefly, Bemisia tabaci, in China.

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Yang, Xin; Xie, Wen; Wang, Shao-li; Wu, Qing-jun; Pan, Hui-peng; Li, Ru-mei; Yang, Ni-na; Liu, Bai-ming; Xu, Bao-yun; Zhou, Xiaomao; Zhang, You-jun

2013-11-01

The sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae), is an invasive and damaging pest of field crops worldwide. The neonicotinoid insecticide imidacloprid has been widely used to control this pest. We assessed the species composition (B vs. Q), imidacloprid resistance, and association between imidacloprid resistance and the expression of five P450 genes for 14-17 B. tabaci populations in 12 provinces in China. Fifteen of 17 populations contained only B. tabaci Q, and two populations contained both B and Q. Seven of 17 populations exhibited moderate to high resistance to imidacloprid, and eight populations exhibited low resistance to imidacloprid, compared with the most susceptible field WHHB population. In a study of 14 of the populations, resistance level was correlated with the expression of the P450 genes CYP6CM1 and CYP4C64 but not with the expression of CYP6CX1, CYP6CX4, or CYP6DZ7. This study indicates that B. tabaci Q has a wider distribution in China than previously reported. Resistance to imidacloprid in field populations of B. tabaci is associated with the increased expression of two cytochrome P450 genes (CYP6CM1 and CYP4C64). Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Response of Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) biotype B to genotypes of pepper Capsicum annuum (Solanales: Solanaceae).

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Ballina-Gomez, H; Ruiz-Sanchez, E; Chan-Cupul, W; Latournerie-Moreno, L; Hernández-Alvarado, L; Islas-Flores, I; Zuñiga-Aguilar, J J

2013-04-01

Bemisia tabaci Genn. biotype B is a widely distributed plant pest that represents one of the major constraints for horticultural crop production. The purpose of the present work was to evaluate the oviposition preference, survivorship, and development of B. tabaci biotype B on semi-cultivated genotypes of Capsicum annuum from southeast Mexico. In free-choice experiments to evaluate the oviposition preference, lower number of eggs laid by B. tabaci biotype B was observed in the genotypes Maax and Xcat´ik relative to that in the commercial genotype Parado. Egg hatchability was significantly lower in Pico Paloma, Bolita, Blanco, Chawa, Payaso, and Xcat´ik than in the rest of the genotypes, including the commercial genotype Jalapeño. Likewise, survivorship of nymphs was significantly lower in Pico Paloma, Bolita, and Blanco than in the remaining genotypes. Nymph developmental time and the period of development from egg to adult were the shortest in Amaxito. Therefore, sources of resistance to B. tabaci biotype B by antibiosis (accumulation of plant defense compounds) might be found in the semi-cultivated genotypes Pico Paloma, Bolita, and Blanco.

Morphological characterization of Capsicum annuum L. accessions from southern Mexico and their response to the Bemisia tabaci-Begomovirus complex

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Horacio Ballina-Gomez

2013-12-01

Full Text Available The high diversity of chili pepper (Capsicum annuum L. in Mexico offers an excellent alternative to search for wild and semi-domesticated genotypes as sources of resistance to the complex Bemisia tabaci (Genn. (Hemiptera: Aleyrodidae-Begomovirus, which has caused enormous losses in commercial production of various horticultural crops. The goal of the present work was to characterize ex situ 18 genotypes of C. annuum from southern Mexico through 47 morphological descriptors, and to evaluate its response to the B. tabaci-Begomovirus complex. Morphological characterization showed the variables calyx annular constriction (CAC, number of branch bifurcation (NBB, and calyx pigmentation (CP had the highest variation. Principal components analysis (PCA of 47 morphological characteristics showed that 12 components were selected as meaningful factors. These components explained 94% of the variation. Cluster analysis showed three major clusters and seven sub-clusters. On the other hand, evaluation of the response to B. tabaci-Begomovirus showed that the genotypes have differential susceptibility to this vector-pathogen complex. Genotypes 'Chawa', 'Blanco', 'Maax' and 'X'catic' were into the low susceptibility to B. tabaci and low severity of viral symptoms. Surprisingly, the genotype 'Simojovel' showed high susceptibility to whitefly, but was grouped into genotypes with low symptom severity. This study shows the potential of native germplasm of pepper to explore sources of resistance to the B. tabaci-Begomovirus complex.

Development of a lateral flow test to detect metabolic resistance in Bemisia tabaci mediated by CYP6CM1, a cytochrome P450 with broad spectrum catalytic efficiency.

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Nauen, Ralf; Wölfel, Katharina; Lueke, Bettina; Myridakis, Antonis; Tsakireli, Dimitra; Roditakis, Emmanouil; Tsagkarakou, Anastasia; Stephanou, Euripides; Vontas, John

2015-06-01

Cotton whitefly, Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae) is a major sucking pest in many agricultural and horticultural cropping systems globally. The frequent use of insecticides of different mode of action classes resulted in populations resisting treatments used to keep numbers under economic damage thresholds. Recently it was shown that resistance to neonicotinoids such as imidacloprid is linked to the over-expression of CYP6CM1, a cytochrome P450 monooxygenase detoxifying imidacloprid and other neonicotinoid insecticides when recombinantly expressed in insect cells. However over-expression of CYP6CM1 is also known to confer cross-resistance to pymetrozine, an insecticide not belonging to the chemical class of neonicotinoids. In addition we were able to demonstrate by LC-MS/MS analysis the metabolisation of pyriproxyfen by recombinantly expressed CYP6CM1. Based on our results CYP6CM1 is one of the most versatile detoxification enzymes yet identified in a pest of agricultural importance, as it detoxifies a diverse range of chemical classes used to control whiteflies. Therefore we developed a field-diagnostic antibody-based lateral flow assay which detects CYP6CM1 protein at levels providing resistance to neonicotinoids and other insecticides. The ELISA based test kit can be used as a diagnostic tool to support resistance management strategies based on the alternation of different modes of action of insecticides. Copyright © 2014 Elsevier Inc. All rights reserved.

Efeito inseticida sistêmico de nanoformulações à base de nim sobre Bemisia tabaci (Hemiptera: Aleyrodidae biótipo B em tomateiro

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Sheila Salles de Carvalho

2015-01-01

Full Text Available Este estudo avaliou a ação inseticida sistêmica e o efeito residual de nanoformulações à base de derivados de nim (Azadirachta indica A. Juss, Meliaceae sobre ninfas de Bemisia tabaci biótipo B (Hemiptera: Aleyrodidae, espécie-praga de diversas culturas de importância econômica. Suspensões coloidais contendo nanocápsulas carregadas com produtos derivados de A. indica foram preparadas utilizando polímeros biodegradáveis como poli-ε-caprolactona (PCL e poli-β-hidroxibutirato (PHB. A matriz encapsulada era composta por uma formulação comercial contendo uma quantidade enriquecida e conhecida dos limonoides azadiractina e 3-tigloilazadiractol (Azamax® 1,2 CE. Inicialmente foi estimada a CL50, para ninfas de B. tabaci, de soluções contendo óleo de nim, que foram aplicadas via água de irrigação (solo em tomateiro. Posteriormente, dois lotes de nanoformulações, com variação no tipo e quantidade dos polímeros e na quantidade do óleo comercial, foram testados quanto à ação sistêmica. As nanoformulações NC L5-2 (com nanocápsulas de PCL e NC L6-1 (com nanocápsulas de PHB, as mais eficazes entre as testadas, foram avaliadas quanto ao efeito residual. A CL50 estimada foi de 180,67 mg L–1 de azadiractina. Constatou-se também que a ação sistêmica de óleos e nanoformulações contendo compostos de nim dependem das condições ambientais em que são aplicados. O Azamax® não apresenta efeito deterrente sobre a oviposição, nem age sobre o desenvolvimento embrionário da mosca-branca quando aplicado via água de irrigação no solo no momento da infestação. As nanoformulações selecionadas são bioativas mesmo cerca de 30 dias após a aplicação, não diferindo do produto comercial.

Thermotolerance and Heat-Shock Protein Gene Expression Patterns in Bemisia tabaci (Hemiptera: Aleyrodidae) Mediterranean in Relation to Developmental Stage.

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Jiang, Rui; Qi, Lan-Da; Du, Yu-Zhou; Li, Yuan-Xi

2017-10-01

Temperature plays an important role in the growth, development, and geographic distribution of insects. There is convincing evidence that heat-shock proteins (HSPs) play important roles in helping organisms adapt to thermal stress. To better understand the physiological and ecological influence of thermal stress on the different development stages of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Mediterranean species (MED), nymphs and adults were shocked with temperatures of 35, 38, and 41℃ for 1 and 2 h, respectively, and the survival rate, fecundity, and developmental duration were investigated in the laboratory. The expression levels of the hsp40, hsp70, and hsp90 genes were assessed using real-time PCR. The results indicate that the survival rates of the nymphs and adults decreased with increased temperature. A 2-h heat shock at 41℃ induced a significant reduction in fecundity in adults and an increase in developmental duration in young nymphs. Hsp90 showed higher temperature responses to thermal stress than hsp40 or hsp70. The expression levels of the hsps in the adults were significantly down-regulated by a 2-h heat shock at 41℃ compared with that by a 1-h treatment. A significant decrease in the expression levels of the hsps also occurred in the adults when the temperature increased from 38 to 41℃ for the 2-h treatment, whereas no significant decrease occurred in the nymphs. Compared with previous studies, we provide some evidence indicating that MED has the potential to adapt to a wider temperature range than the Middle East-Asia Minor 1 species. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Distribuição espacial de Aphis gossypii (Glover (Hemiptera, Aphididae e Bemisia tabaci (Gennadius biótipo B (Hemiptera, Aleyrodidae em algodoeiro Bt e não-Bt Spatial distribution of Aphis gossypii (Glover (Hemiptera, Aphididae and Bemisia tabaci (Gennadius biotype B (Hemiptera, Aleyrodidae on Bt and non-Bt cotton

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Tatiana Rojas Rodrigues

2010-03-01

Full Text Available Distribuição espacial de Aphis gossypii (Glover (Hemiptera, Aphididae e Bemisia tabaci (Gennadius biótipo B (Hemiptera, Aleyrodidae em algodoeiro Bt e não-Bt. O estudo da distribuição espacial de adultos de Bemisia tabaci e de Aphis gossypii nas culturas do algodoeiro Bt e não-Bt é fundamental para a otimização de técnicas de amostragens, além de revelar diferenças de comportamento de espécies não-alvo dessa tecnologia Bt entre as duas cultivares. Nesse sentido, o experimento buscou investigar o padrão da distribuição espacial dessas espécies de insetos no algodoeiro convencional não-Bt e no cultivar Bt. As avaliações ocorreram em dois campos de 5.000 m² cada, nos quais se realizou 14 avaliações com contagem de adultos da mosca-branca e colônias de pulgões. Foram calculados os índices de agregação (razão variância/média, índice de Morisita e Expoente k da Distribuição Binomial Negativa e realizados os testes ajustes das classes numéricas de indivíduos encontradas e esperadas às distribuições teóricas de freqüência (Poisson, Binomial Negativa e Binomial Positiva. Todas as análises mostraram que, em ambas as cultivares, a distribuição espacial de B. tabaci ajustou-se a distribuição binomial negativa durante todo o período analisado, indicando que a cultivar transgênica não influenciou o padrão de distribuição agregada desse inseto. Já com relação às análises para A. gossypii, os índices de agregação apontaram distribuição agregada nas duas cultivares, mas as distribuições de freqüência permitiram concluir a ocorrência de distribuição agregada apenas no algodoeiro convencional, pois não houve nenhum ajuste para os dados na cultivar Bt. Isso indica que o algodão Bt alterou o padrão normal de dispersão dos pulgões no cultivo.The study of spatial distribution of the adults of Bemisia tabaci and the colonies of Aphis gossypii on Bt and non-Bt cotton crop is fundamental for

Effectiveness of two insect growth regulators against Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) and Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) and their impact on population densities of arthropod predators in cotton in Pakistan.

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Gogi, Muhammad D; Sarfraz, Rana M; Dosdall, Lloyd M; Arif, Muhammad J; Keddie, Andrew B; Ashfaq, Muhammad

2006-10-01

Field efficacies of two insect growth regulators (IGRs) at two recommended application rates, buprofezin at 370 and 555 g AI ha(-1) and lufenuron at 37 and 49 g AI ha(-1), were determined against the sweet potato whitefly, Bemisia tabaci (Gennadius), and the cotton bollworm, Helicoverpa armigera (Hübner), in experimental plots of cotton at the Directorate of Cotton Research, Faisalabad, Pakistan. Adverse effects of the IGRs on populations of associated arthropod predators, namely geocorids, chrysopids, coccinellids, formicids and arachnids, were also assessed. Both IGRs significantly reduced populations of B. tabaci at each application rate 24, 48 and 72 h after treatment, and higher doses were more effective than lower doses. Buprofezin was not effective against H. armigera at any tested dose for any time of treatment in any spray. Lufenuron applied at 37 and 49 g AI ha(-1) effectively suppressed H. armigera populations, resulting in significant reductions in crop damage. At lower doses, both IGRs appeared safe to predator populations, which did not differ significantly in IGR-treated versus untreated control plots. Population densities of formicids and coccinellids were significantly lower at high concentrations of both IGRs in treatment plots, possibly as a result of reduced prey availability. The potential role of buprofezin and lufenuron for control of B. tabaci and H. armigera in a spray programme and the likelihood of direct toxic effects of IGRs on predatory fauna of cotton are discussed.

Caracterización in silico de las proteínas del choque térmico Hsp70 y Hsp90 deBemisia tabaci (Hemiptera: Aleyrodidae y su posible actividad adaptativa

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Eneida Torres Cabra

2014-06-01

Full Text Available La mosca blanca, Bemisia tabaci (Hemiptera: Aleyrodidae es una de las plagas más destructivas e invasivas en el mundo, ataca una gran cantidad de cultivos. Se adapta fácilmente a plantas hospederas y a nuevas regiones geográficas, lo que sugiere el desarrollo de mecanismos de control a daños producidos por factores estresantes. Las proteínas Hsp se expresanen los organismos como mecanismo de defensa, actúan como chaperonas en el correcto ensamblaje de las proteínas. En este estudio se realizó una caracterizaciónin silico de las proteínas Hsp70 y Hsp90 de B. tabaci, secuencias obtenidas de NCBI. La determinaciónde los perfiles de hidrofobicidad, polaridad, accesibilidady flexibilidad se obtuvieron con “ProScale” de ExPASy, el perfil de antigenicidad con JaMBW. La secuencia aminoacídica se analizó con GOR IV y SOPMA y la composición de aminoácidos con ProtParam. Para analizar el peso molecular, índice deinestabilidad, índice alifático y gradiente hidropático,con GRAVY. La estructura terciaria se obtuvo con HHpred, y ESyPred3D. Para validar las estructuras 3D se utilizó Procheck, What_check y errat. Hsp70 y Hsp90 de B. tabaci presentan valores bajos de hidrofobicidady altos de polaridad, flexibilidad y accesibilidad, características que le permiten a las proteínas extender su capacidad como chaperonas. La Hsp70tiene una estructura secundaria compuesta por 41-45% alfa hélices, 30-43% coil y menos del 6% en hoja plegada y la Hsp90 por 52 y 53% hélices, 26-34% coily 6% hoja plegada. Las Hsp juegan un rol importante en los insectos debido a su tamaño y corto ciclo de vida, pues la temperatura influye en su distribución y abundancia.

The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci

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Xiaobin Shi

2016-06-01

Full Text Available The whitefly Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV. The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles—especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles.

Asymmetric consequences of host plant occupation on the competition between the whiteflies Bemisia tabaci cryptic species MEAM1 and Trialeurodes vaporariorum (Hemiptera: Aleyrodidae).

Science.gov (United States)

Zhang, Gui-Fen; Lövei, Gábor L; Hu, Man; Wan, Fang-Hao

2014-12-01

The two common whitefly species, Bemisia tabaci (Gennadius) MEAM1 and Trialeurodes vaporariorum (Westwood), often co-occur on their host plants. The effect of host plant occupation by one species on later-arriving conspecific individuals or on the other competing species was examined. Resource preoccupied by T. vaporariorum had mostly negative effects on the life history parameters of later-arriving conspecifics. Red-eyed nymph and immature survival of T. vaporariorum decreased when resource was preoccupied by conspecifics, irrespective of the previous occupation scenario. However, resource preoccupied by T. vaporariorum had only minor detrimental effects on the performance of later-arriving B. tabaci MEAM1. In the opposite colonisation sequence, previous occupation by B. tabaci MEAM1 had no significant effects on the life history parameters of later-arriving conspecifics, but severe detrimental effects were observed on the performance of later-arriving T. vaporariorum. Total immature survival of T. vaporariorum decreased in both weak and strong previous occupation situations by B. tabaci MEAM1. The interspecific interactions between B. tabaci MEAM1 and T. vaporariorum were asymmetric, with B. tabaci MEAM1 being the superior competitor. This superiority could partially explain the rapid spread of B. tabaci MEAM1 in China. © 2013 Society of Chemical Industry.

Biological aspects of Bemisia tabaci (Genn.) B biotype (Hemiptera: Aleyrodidae) on six bean genotypes; Aspectos biologicos de Bemisia tabaci (Genn.) biotipo B (Hemiptera: Aleyrodidae) em seis genotipos de feijoeiro

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Oriani, Maria A. de G. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Ecologia e Biologia Evolutiva; Vendramin, Jose D. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. de Entomologia, Fitopatologia e Zoologia Agricola; Brunherotto, Rogerio [Fundacao Municipal de Ensino Superior de Braganca Paulista, SP (Brazil)

2008-03-15

The silverleaf whitefly is one of the most harmful pests that attack bean crops, mainly for extracting large quantities of phloem sap and transmitting the bean golden mosaic virus. Resistant germplasm plants can be an important method for controlling this pest. The biological aspects of Bemisia tabaci B biotype on bean (Phaseolus vulgaris) genotypes were evaluated. The tests were conducted under laboratory conditions, with the following genotypes: Arc 1, Arc 3s, Arc 5s, G13028, G11056 and Porrillo 70. The bean plants in a stage IV-1 were infested during one day with silverleaf white flies. Afterwards the eggs and nymphs were observed until adult emergence. Longevity and fecundity of emerged insects were also evaluated. The longest development time occurred for nymphs fed on Arc 3s genotype (26.5 days), following by G11056 (25.9 days) and G13028 (25.3 days). The development period was 5.5 days longer in Arc 3s when compared with Porrillo 70. Also, the wild genotypes Arc 3s and G11056 showed higher mortality rates (94.7% and 83.1%, respectively), which may suggest antibiosis and/or feeding non preference resistance type. For this reason, although longevity and fecundity were not influenced when the whitefly fed on resistant genotypes (Arc 3s, G11056, G13028 and Arc 5s), those genotypes can be used for bean breeding program towards B. tabaci B biotype. (author)

The Effects of Some Botanical Insecticides and Pymetrozine on Life Table Parameters of Silver Leaf Whitefly Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae

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Reihaneh Barati

2013-01-01

Full Text Available The objective of this research was to assess the effects of extracts of two medicinalplant species: Allium sativum (Linn and Calotropis procera (Aiton, and a formulation containingazadirachtin on life table parameters of silver leaf whitefly (SLW, Bemisia tabaci biotypeB (Gennadius (Hemiptera: Aleyrodidae, grown on greenhouse tomato plants. Theeffects were compared to that of pymetrozine, a synthetic insecticide. Bioassays were carriedout in a greenhouse under controlled conditions of 27 ± 2°C, R.H. of 55 ± 5% and 16:8h (L:D photo period.All treatments significantly affected the survivorship and fertility of SLW female adults,reducing the net reproduction rate, mean generation time and intrinsic rate of increase ofthis insect.The net reproductive rate [R0] values for the populations treated with garlic extract,milkweed extract, pymetrozine, azadirachtin, control for extracts (ethanol + distilled waterand control for pesticides (distilled water were 23.58, 19.32, 10.78, 8.23, 49.66, 57.55; theintrinsic rate of increases [rm] were 0.134, 0.139, 0.110, 0.090, 0.177, 0.178; the mean generationtimes [T] were 23.49, 21.23, 21.66, 23.50, 22.06, 22.69; the doubling times [DT] were 5.14,4.95, 6.27, 7.56, 3.91, 3.87, and the finite rates of increase [λ] were 1.144, 1.149, 1.116, 1.094, 1.193,1.195, respectively. Azadirachtin had the highest effect on the life table parameters of SLW.Our findings indicated that, although herbal extracts were not effective as much asthe chemical insecticides, they can be effective in pest control. Therefore, they are suitablechoices for replacing chemical insecticides and for alternative use with azadirachtin inSLW IPM program.

High Level of Nitrogen Makes Tomato Plants Releasing Less Volatiles and Attracting More Bemisia tabaci (Hemiptera: Aleyrodidae)

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Islam, Md. Nazrul; Hasanuzzaman, Abu Tayeb Mohammad; Zhang, Zhan-Feng; Zhang, Yi; Liu, Tong-Xian

2017-01-01

Tomato (Solanum lycopersicum) production is seriously hampered by the infestation of the sweetpotato whitefly, Bemisia tabaci MEAM 1 (Middle East-Asia Minor 1). The infestation behavior of the whiteflies could be affected by the quantity of plant released volatile organic compounds (VOCs) related to nitrogen concentrations of the plant. In this study, we determined the infestation behavior of B. tabaci to the tomato plants that produced different levels of VOCs after application of different levels of nitrogen with a wind tunnel and an olfactometer. We also analyzed the VOCs released from nitrogen-treated tomato plants using solid phase microextraction and gas chromatography-mass spectrometry. The results revealed that the production of eight VOCs (β-pinene, (+)-4-carene, α-terpinene, p-cymene, β-phellandrene, α-copaene, β-caryophyllene, and α-humulene) was reduced after the plants were treated with high levels of nitrogen. However, more whiteflies were attracted to the tomato plants treated with high levels of nitrogen than to the plants treated with normal or below normal levels of nitrogen. These results clearly indicated that nitrogen can change the quality and quantity of tomato plant volatile chemicals, which play important roles in B. tabaci host plant selection. PMID:28408917

Keanekaragaman dan Kelimpahan Musuh Alami Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae pada Pertanaman Cabai Merah di Kecamatan Pakem, Kabupaten Sleman, Daerah Istimewa Yogyakarta

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Hendrival Hendrival

2015-09-01

Full Text Available Research on natural enemies of Bemisia tabaci was conducted in the chili pepper fields in Sub-district of Pakem, District of Sleman, The Special Province of Yogyakarta during the dry season of May-October 2009. The aims of this research were to study the diversity and abundance of parasitoid and predator species associated with B. tabaci. Samplings of insect species were done using yellow pan trap, sweep net, direct observation of insects colonized young leaves, and collection of nymphs for B. tabaci. Measurement of insect diversity was calculated using Shannon’s index diversity and Evenness index. Nine species of insect predator were identified, i.e. Harmonia octomaculata (Fabricius, Menochilus sexmaculata (Fabricius, Scymnus sp., Micraspis inops Mulsant, Coccinella sp. (Coleoptera: Coccinellidae, Paederus fuscipes Curtis (Coleoptera: Staphylinidae, Orius sp. (Hemiptera: Anthocoridae, Linyphiidae sp.1 (Araneae, and Syrphidae sp.1 (Diptera. Eretmocerus sp. (Hymenoptera: Aphelinidae was the only parasitoid found in the nymphs B. tabaci collected and has the potential to control B. tabaci in the red pepper fields.

Oviposition behavior of the silver leaf whitefly Bemisia tabaci biotype B on tomato; Comportamento de oviposicao da mosca-branca Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) biotipo B em tomateiro

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Vendramim, Jose D. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. de Entomologia, Fitopatologia e Zoologia Agricola]. E-mail: jdvendra@esalq.usp.br; Souza, Antonio P. de [Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Dept. de Morfofisiologia. Lab. de Anatomia Humana]. E-mail: apsouza@nin.ufms.br; Ongarelli, Maria das G. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Lab. de Fisiologia e Bioquimica Pos-Colheita]. E-mail: mgong@esalq.usp.br

2009-01-15

The objective of this work was to evaluate the influence of the leaf surface, the insect geotropic behavior and the type of foliar trichome on Bemisia tabaci (Genn.) biotype B oviposition on tomato leaves. Bemisia tabaci females were confined in acrylic boxes in which tomato leaflets were fixed at the bottom and top part of the boxes to allow insects to access the leaf surface to be tested (adaxial and/or abaxial) in both no-choice and free choice tests. Oviposition was always higher when the leaf was offered at the top of the box and preferably at the abaxial leaf surface. The effects of leaf trichomes (glandular and non glandular) on B. tabaci oviposition was evaluated by offering the abaxial surface of tomato leaflets to females after a 70% ethanol wash to remove glandular exsudates against a control treatment (without a ethanol wash). Oviposition was concentrated mostly near to non glandular trichomes, showing whitefly females can discriminate among the trichomes. (author)

Indutores de resistência à mosca-branca Bemisia tabaci Biótipo B (GENN., 1889 (Hemiptera: Aleyrodidae em soja Resistance inducers to the whitefly Bemisia tabaci Biotype B (GENN., 1889 (Hemiptera: Aleyrodidae in soybeans

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Jair Campos Moraes

2009-10-01

Full Text Available Objetivou-se, neste trabalho, avaliar o efeito da aplicação de indutores na resistência de duas cultivares de soja à mosca-branca Bemisia tabaci biótipo B. O experimento foi conduzido no Departamento de Entomologia - UFLA. As sementes de soja, cultivar IAC-19 e MONSOY-8001, foram previamente tratadas com o fungicida captan. Foram testados os seguintes tratamentos: T1- irrigação no solo, ao redor das plantas de cada vaso, de 250 mL de solução de ácido silícico a 1%; T2- pulverização das plantas, até o ponto de escorrimento, com solução a 0,3% de acibenzolar-s-methyl; T3- pulverização das plantas, até o ponto de escorrimento, com calda a 0,24% de pyraclostrobin+epoxiconazole e T4- testemunha. As plantas foram infestadas com 100 adultos da mosca-branca por vaso que liberados oito dias após a aplicação dos tratamentos. Avaliaram-se o número de ovos na face abaxial de cada folha, que foi marcada para posterior avaliação de ninfas; teores de taninos e de lignina; peso seco das raízes e da parte aérea. Não houve diferença para número de ovos e ninfas entre as cultivares de soja, porém, a viabilidade média de B. tabaci foi menor a cultivar IAC-19. O cultivar de soja IAC-19 demonstrou moderada resistência ao biótipo B de B. tabaci. A aplicação de silício ou acibenzolar-s-methyl induz um aumento no teor de lignina na cultivar de soja IAC-19.The objective of this paper was to evaluate the effect of the application of inducers on the resistance of two soybean cultivars to the whitefly B. tabaci Biotype B. The experiment was carried out at the Entomology Department - UFLA. The soybean seeds of cultivars IAC-19 and MONSOY-8001 were previously treated with Captan fungicide. The following treatments were tested: T1- irrigating the soil around the plants of each pot with 250 mL of solution of 1% silicic acid; T2- spraying of the plants, to the 'point of dripping', with a solution of 0.3% acibenzolar-s-methyl; T3- spraying of

Controle químico de ovos e ninfas de Bemisia tabaci biótipo B (Hemiptera: aleyrodidae Chemical control of Bemisia tabaci B biotype (Hemiptera: aleyrodidae eggs and nymphs

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Giuliana Etore do Valle

2002-06-01

Full Text Available Moscas brancas são pragas de diversas culturas, causam redução na produção e na qualidade do produto. Inseticidas, com diferentes modos de ação vêm sendo utilizados, sem muito sucesso. Neste trabalho avaliou-se a eficiência de inseticidas sobre ovos de diferentes idades (1, 3 e 5 dias e de ninfas de 1° ínstar da mosca branca Bemisia tabaci biótipo B. Os experimentos foram realizados em condições de laboratório, sob temperatura de 25 ± 2°C e fotofase de 12 horas. Piriproxifem (75 mg L-1 atuou como excelente ovicida, sendo altamente eficiente, 3 dias de idade. Cartape (500 mg L-1 não teve efeito satisfatório, mas a 1000 mg L-1 foi eficiente em ovos com até 5 dias de idade. Quanto à ação sobre ninfas de 1° ínstar, para pulverizações na face superior das folhas, piriproxifem, a 75 mg L-1, apresentou eficiência na supressão da emergência de adultos, caracterizando presença de ação translaminar; buprofezim, cartape, acefato e fempiroximate não apresentaram eficiência no controle de ninfas. Quando aplicado na face inferior das folhas, buprofezim (375 mg L-1 apresentou eficiência comparável à de piriproxifem, impedindo a emergência de adultos.Whiteflies are pests of many crops, cause severe yield losses and reduce crop quality. Insecticides of different modes of action have been used without success. In this work, the efficiency of five insecticides on Bemisia tabaci B biotype (= B. argentifolii eggs and nymphs was evaluated under laboratory conditions (T = 25 ± 2°C; 12 h photophase. In relation to the ovicidal effect, pyriproxyfen (75 mg L-1 caused egg hatching inhibition up to three day old eggs. Cartap showed efficiency only at the concentration of 1000 mg L-1, supressing the viability of eggs up to five days. Soybean leaves with first instar nymphs were treated in the upper surface with pyriproxyfen (75 mg L-1, buprofezin (375 mg L-1, cartap (1000 mg L-1, acephate (750 mg L-1 and fenpyroximate (100 mg L-1; in

Evaluation of insecticides against cotton whitefly, bemisia tabachi (Genn.) (Homoptera: Aleyrodidae)

International Nuclear Information System (INIS)

Razaq, M.; Aslam, M.; Sharif, K.; Salman, B.; Aleem, F.

2003-01-01

The experiment was conducted to evaluate the efficacy of lmidacloprid (Confidor 200SL), Acetamaprid (Mospilon 20SP), Methamidophos (Tamaron 600SL), Endosulfan (Thioluxon 35EC), Buprofezin (Sitara 25WP), Fenpropathrin (Fenthrin 20EC) and Diafenthiuron (Polo 500 SC) against whitefly, Bemisia tabaci (Genn.) on cotton variety CIM-473 during the crop year 2002. The crop was sprayed twice in September. After seven days of the first spray, the lowest population (0.6/leaf) of whitefly was observed in plots treated with Endosulfan 35EC followed by Acetamaprid 20SP(1.1/leaf), while the plots receiving Buprofezin 25 WP + Fenpropathrin 20 EC, Methamidophos 600SL and Imidacloprid 200SL had population of whitefly statistically similar. Seven days after second spray Acetamaprid 20SP and Diafenthiuron 500SC treated plots had the lowest population (1.4 per leaf) of whitefly followed by Imidacloprid 200SL (1.8 per leaf) and Fenpropathrin 20EC (1.9 per leaf).(author)

Mosca-Branca, Bemisia tabaci (Genn. (Hemiptera: Aleyrodidae em feijoeiro: Características gerais, bioecologia e métodos de controle

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Anderson Silva

2017-04-01

Abstract. Common bean plants are infested by insects, which can ultimately affect the crop production before and after harvest, with estimated losses ranging from 33 to 86%. Among the insect pests infesting the common beans the whitefly Bemisia tabaci (Genn. stands out. This species cause direct injury by feeding on the plants and indirect injury by excreting sugary honeydew that is after colonized by the sooty mold. In addition, the most serious damage caused by B. tabaci is the transmission of virus diseases, especially the common bean golden mosaic, responsible for economic losses varying from 30 to 100%. This review aims at providing information on important aspects of B. tabaci including its geographical distribution, bioecology, population dynamics, host plants, and methods of pest control. We expect that this review can provide valuable subsidies for future studies on the whitefly in common beans.

Bemisia tabaci MED (Q biotype) (Hemiptera: Aleyrodidae)is on the move in Florida to residential landscapes and may impact open field agriculture

Science.gov (United States)

Bemisia tabaci MED (Mediterranean) have been in the United States for approximately a dozen years spreading to 26 states since it was first detected in Arizona at a retail outlet on poinsettia in 2004. Indistinguishable morphologically from silverleaf whitefly (Bemisia tabaci MEAM1 (Middle Eastern A...

Susceptibility of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) to imidacloprid, thiamethoxam, dinotefuran and flupyradifurone in south Florida

Science.gov (United States)

Populations of Bemisa tabaci Middle East Asia Minor 1 (MEAM 1) were established from nineteen locations in south Florida, primarily from commercial tomato fields, and were tested using a cotton leaf petiole systemic uptake method for susceptibility to the nicotinic acetylcholine agonist insecticides...

Biological aspects of Bemisia tabaci (Genn.) B biotype (Hemiptera: Aleyrodidae) on six bean genotypes

International Nuclear Information System (INIS)

Oriani, Maria A. de G.

2008-01-01

The silverleaf whitefly is one of the most harmful pests that attack bean crops, mainly for extracting large quantities of phloem sap and transmitting the bean golden mosaic virus. Resistant germplasm plants can be an important method for controlling this pest. The biological aspects of Bemisia tabaci B biotype on bean (Phaseolus vulgaris) genotypes were evaluated. The tests were conducted under laboratory conditions, with the following genotypes: Arc 1, Arc 3s, Arc 5s, G13028, G11056 and Porrillo 70. The bean plants in a stage IV-1 were infested during one day with silverleaf white flies. Afterwards the eggs and nymphs were observed until adult emergence. Longevity and fecundity of emerged insects were also evaluated. The longest development time occurred for nymphs fed on Arc 3s genotype (26.5 days), following by G11056 (25.9 days) and G13028 (25.3 days). The development period was 5.5 days longer in Arc 3s when compared with Porrillo 70. Also, the wild genotypes Arc 3s and G11056 showed higher mortality rates (94.7% and 83.1%, respectively), which may suggest antibiosis and/or feeding non preference resistance type. For this reason, although longevity and fecundity were not influenced when the whitefly fed on resistant genotypes (Arc 3s, G11056, G13028 and Arc 5s), those genotypes can be used for bean breeding program towards B. tabaci B biotype. (author)

First report and differential colonization of Passiflora species by the B biotype of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in Brazil

International Nuclear Information System (INIS)

Nunes, Endson S.; Vieira, Maria L.C.; Lourencao, Andre L.; Piedade, Sonia M.S.

2008-01-01

This note is the first report of Bemisia tabaci (Gennadius) biotype B colonizing passionvine in Brazil. We examined the colonization of nine Passiflora species by a wild B type population under greenhouse conditions. P. amethystina Mikan was the most preferred species for oviposition and colonization, whereas P. suberosa L., P. coriacea Juss. and two commercially cultivated species, P. alata Curtis and P. edulis Sims f. flavicarpa Degener, were mostly uncolonised. P. morifolia Mast., P. cincinnata Mast., P. foetida L. and P. caerulea L. showed intermediate levels of colonization. Such differential colonization might suggest some degree of resistance by certain Passiflora species or oviposition preference by B. tabaci. (author)

First report and differential colonization of Passiflora species by the B biotype of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in Brazil

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Nunes, Endson S.; Vieira, Maria L.C. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ-USP), Piracicaba, SP (Brazil). Dept. de Genetica]. E-mail: esnunes@carpa.ciagri.usp.br; mlcvieir@esalq.usp.br; Brown, Judith K. [University of Arizona, Tucson, AZ (United States). Dept. of Plant Sciences]. E-mail: jbrown@Ag.arizona.edu; Moreira, Adriana G.; Rezende, Jorge A.M. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ-USP), Piracicaba, SP (Brazil). Dept. de Entomologia, Fitopatologia e Zoologia Agricola]. E-mails: agmoreir@esalq.usp.br; amrezen@esalq.usp.br; Watson, Gillian [California Dept. of Food and Agriculture, Sacramento, CA (United States)]. E-mail: gwatson@cdfa.ca.gov; Lourencao, Andre L. [Instituto Agronomico, Campinas, SP (Brazil). Centro de Pesquisa e Desenvolvimento de Fitossanidade]. E-mail: andre@iac.sp.gov.br; Piedade, Sonia M.S. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ-USP), Piracicaba, SP (Brazil). Dept. de Ciencias Exatas]. E-mail: jsoniamsp@esalq.usp.br

2008-11-15

This note is the first report of Bemisia tabaci (Gennadius) biotype B colonizing passionvine in Brazil. We examined the colonization of nine Passiflora species by a wild B type population under greenhouse conditions. P. amethystina Mikan was the most preferred species for oviposition and colonization, whereas P. suberosa L., P. coriacea Juss. and two commercially cultivated species, P. alata Curtis and P. edulis Sims f. flavicarpa Degener, were mostly uncolonised. P. morifolia Mast., P. cincinnata Mast., P. foetida L. and P. caerulea L. showed intermediate levels of colonization. Such differential colonization might suggest some degree of resistance by certain Passiflora species or oviposition preference by B. tabaci. (author)

Efficiency of neem oil nanoformulations to Bemisia tabaci (GENN. Biotype B (Hemiptera: AleyrodidaeEficiência de nanoformulações a base de óleo de nim sobre Bemisia tabaci (GENN. Biótipo B (Hemiptera: Aleyrodidae

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Sheila Salles Carvalho

2012-04-01

Full Text Available The nanotechnology, through encapsulation of active ingredients, has showed an important way to avoid problems with quickly degradation of the pesticide molecules. Thus, neem (Azadirachta indica oil nanoformulations containing ?-ciclodextrin and poli-?-caprolactone (PCL were tested as to their control efficiency against eggs and nymphs of Bemisia tabaci (Genn. biotype B reared in soybean. The Lethal Concentration (LC50 was estimated using a commercial neem oil (Organic Neem® on first-instar nymphs to establish the adequate volume of the nanoformulations per treatment. After that, they were sprayed on eggs and first-instar nymphs in laboratory and greenhouse and on third-instar nymphs in greenhouse. The commercial neem oil and distilled water were used as controls. Egg viability was not affected by any treatment. Among six nanoformulations, only one was efficient against the first-instar nymphs in laboratory conditions. However, its effective period was not increased as expected. In greenhouse, first-instar nymphs were more affected by two nanoformulations which were significantly different of the commercial neem oil - the most effective one. No mortality differences among the formulations in the third-instar test were observed. The nanoformulations were less efficient to control the B. tabaci biotype B nymphs than the commercial neem oil. A nanotecnologia, através do encapsulamento de ingredientes ativos, tem-se revelado uma importante estratégia para evitar problemas com a rápida degradação de moléculas inseticidas. Assim, nanoformulações à base de óleo de nim (Azadirachta indica utilizando os polímeros ?-ciclodextrina e poli-?-caprolactona (PCL foram testadas quanto a sua eficiência de controle de ovos e ninfas de Bemisia tabaci (Genn. biótipo B mantidas em soja. Foi estimada a CL50 utilizando uma formulação comecial de óleo de nim (Organic Neem® sobre ninfas em 1º ínstar da qual se estipulou o volume das nanoformula

Is agriculture driving the diversification of the Bemisia tabaci species complex (Hemiptera: Sternorrhyncha: Aleyrodidae)?: Dating, diversification and biogeographic evidence revealed.

Science.gov (United States)

Boykin, Laura M; Bell, Charles D; Evans, Gregory; Small, Ian; De Barro, Paul J

2013-10-18

Humans and insect herbivores are competing for the same food crops and have been for thousands of years. Despite considerable advances in crop pest management, losses due to insects remain considerable. The global homogenisation of agriculture has supported the range expansion of numerous insect pests and has been driven in part by human-assisted dispersal supported through rapid global trade and low-cost air passenger transport. One of these pests, is the whitefly, Bemisia tabaci, a cryptic species complex that contains some of the world's most damaging pests of agriculture. The complex shows considerable genetic diversity and strong phylogeographic relationships. One consequence of the considerable impact that members of the B. tabaci complex have on agriculture, is the view that human activity, particularly in relation to agricultural practices, such as use of insecticides, has driven the diversification found within the species complex. This has been particularly so in the case of two members of the complex, Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED), which have become globally distributed invasive species. An alternative hypothesis is that diversification is due to paleogeographic and paleoclimatological changes. The idea that human activity is driving speciation within the B. tabaci complex has never been tested, but the increased interest in fossil whiteflies and the growth in molecular data have enabled us to apply a relaxed molecular clock and so estimate divergence dates for the major lineages within the B. tabaci species complex. The divergence estimates do not support the view that human activity has been a major driver of diversification. Our analysis suggests that the major lineages within the complex arose approximately 60-30 mya and the highly invasive MED and MEAM1 split from the rest of the species complex around 12 mya well before the evolution of Homo sapiens and agriculture. Furthermore, the divergence dates coincide with a period

Understanding biological control of greenhouse whitefly with the parasitoid Encarsia formosa : from individual behaviour to population dynamics

NARCIS (Netherlands)

Roermund, van H.J.W.

1995-01-01

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Homoptera, Aleyrodidae), is a very common, highly polyphagous pest insect all over the world. Biological control of whiteflies with the parasitoid Encarsia formosa Gahan (Hymenoptera, Aphelinidae) was already applied in the 1920s in

Fatores que influenciam o ataque de mosca-branca em jiloeiro Factors affecting attack rate of the whitefly on Solanum gilo

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Germano Leão Demolin Leite

2002-07-01

Full Text Available Este trabalho objetivou determinar os efeitos de pluviosidade e temperatura, predadores e parasitóides, dossel e idade das plantas, tipos e densidades de tricomas foliares, compostos químicos foliares, níveis de N e de K foliares, sobre a intensidade de ataque de mosca-branca Bemisia tabaci (Hemiptera: Aleyrodidae em jiloeiro Solanum gilo var. 'Gigante Portuguesa'. As densidades de ninfas e de adultos de B. tabaci foram maiores nas folhas baixeiras do que nas apicais das plantas de jiloeiro. Com o aumento da temperatura do ar, observou-se incremento na densidade de adultos de B. tabaci nas folhas de jiloeiro.The objective of this study was to determine the effect of rainfall and temperature, predators and parasitoids, height within the canopy and plant age, chemical composition of leaves, levels of nitrogen and potassium in leaves and density of trichomes in leaves, on attack intensity of the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae on Solanum gilo var. 'Portuguese giant'. Densities of nymphs and of adults of B. tabaci were higher on leaves of the lower part than on those of the apical parts of plants of S. gilo. The number of adults of B. tabaci on leaves of S. gilo increased with temperature.

Nigerian Journal of Horticultural Science - Vol 13, No 1 (2008)

African Journals Online (AJOL)

Spread of the spiraling white fly Aleurodicus dispersus (Homoptera: Aleyrodidae) and its parasitoids Encarcia species (Hymenoptera: Aphelinidae) on horticultural plants in ... Nutrient release patterns of kola pod husk and pacesetter grade b fertilizer during incubation in the laboratory · EMAIL FULL TEXT EMAIL FULL TEXT

Status of Resistance of Bemisia tabaci (Hemiptera: Aleyrodidae) to Neonicotinoids in Iran and Detoxification by Cytochrome P450-Dependent Monooxygenases.

Science.gov (United States)

Basij, M; Talebi, K; Ghadamyari, M; Hosseininaveh, V; Salami, S A

2017-02-01

Nine Bemisia tabaci (Gennadius) populations were collected from different regions of Iran. In all nine populations, only one biotype (B biotype) was detected. Susceptibilities of these populations to imidacloprid and acetamiprid were assayed. The lethal concentration 50 values (LC 50 ) for different populations showed a significant discrepancy in the susceptibility of B. tabaci to imidacloprid (3.76 to 772.06 mg l -1 ) and acetamiprid (4.96 to 865 mg l -1 ). The resistance ratio of the populations ranged from 9.72 to 205.20 for imidacloprid and 6.38 to 174.57 for acetamiprid. The synergistic effects of piperonylbutoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) were evaluated for the susceptible (RF) and resistant (JR) populations for the determination of the involvement of cytochrome P450-dependent monooxygenase and carboxylesterase, respectively, in their resistance mechanisms. The results showed that PBO overcame the resistance of the JR population to both imidacloprid and acetamiprid, with synergistic ratios of 72.7 and 106.9, respectively. Carboxylesterase, glutathione S-transferase and cytochrome P450-dependent monooxygenase were studied biochemically, for the purpose of measuring the activity of the metabolizing enzymes in order to determine which enzymes are directly involved in neonicotinoid resistance. There was an increase in the activity of cytochrome P450-dependent monooxygenase up to 17-fold in the resistant JR population (RR = 205.20). The most plausible activity of cytochrome P450-dependent monooxygenase correlated with the resistances of imidacloprid and acetamiprid, and this suggests that cytochrome P450-dependent monooxygenase is the only enzyme system responsible for neonicotinoid resistance in the nine populations of B. tabaci.

Resposta de fêmeas de Encarsia formosa Gahan (Hymenoptera: Aphelinidae aos odores do hospedeiro e da planta-hospedeira em olfatômetro de quatro vias Response of female Encarsia formosa Gahan (Hymenoptera: Aphelinidae to host and plant-host odors

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Kátia Maria Medeiros de Siqueira

2003-01-01

Full Text Available A crescente importância da mosca-branca Bemisia tabaci raça B (Hemiptera: Aleyrodidae como praga agrícola tem incentivado a busca de inimigos naturais que possam ser utilizados em programas de controle biológico. Estudou-se a atração de fêmeas de Encarsia formosa (Hymenoptera: Aphelinidae aos odores emanados pelo seu hospedeiro - a mosca-branca B. tabaci raça B - em plantas de tomate, em olfatômetro de quatro vias. O parasitóide não apresentou atração aos odores da planta de tomate nem ao complexo planta de tomate-ninfas de B. tabaci.The increasing importance of the whitefly Bemisia tabaci race B (Hemiptera: Aleyrodidae as one of the major agricultural pest of this century, has resulted in a search for natural enemies that can be used in biological control programs. The response of naive females of Encarsia formosa (Hymenoptera: Aphelinidaeto volatiles from its hostspecies: insect (B. tabacci race B and plant (Lycopersicom esculentum Mill. were tested using 4-nose olfactometre. Parasitoid was not attracted by neither or insect hostspecies volatile.

Assesing Bemisia tabaci (Genn. biotype B resistance in soybean genotypes: Antixenosis and antibiosis Evaluación de la resistencia de genotipos de soya a Bemisia tabaci (Genn. biotipo B: Antixenosis y antibiosis

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José Paulo Gonçalves Franco da Silva

2012-12-01

Full Text Available Since it was first reported in Brazil in the 1990s, the B biotype of silverleaf whitefly (Bemisia tabaci Genn., Hemiptera: Aleyrodidae has been recognized as an important pest in soybeans (Glycine max L., reducing the productivity of this legume species in some areas of the country. As an alternative to chemical control, the use of resistant genotypes represents an important tool for integrated pest management (IPM. This study evaluated the performance of 10 soybean genotypes prior to whitefly infestation, by testing attractiveness and preference for oviposition in the greenhouse and antibiosis in the laboratory. In a multiple-choice test, 'IAC-17' was the least attractive to insects. In a no-choice test, 'IAC-17' was the least attractive for egg deposition, indicating the occurrence of non-preference for oviposition on this genotype. Trichome density was positively correlated with the oviposition site and may be associated with the resistance of 'IAC-17' to infestation. The genotypes 'IAC-PL1', 'IAC-19', 'Conquista', 'IAC-24' and 'IAC-17' extended the insect's life cycle, indicating the occurrence of a small degree of antibiosis and/or non-preference for feeding.Desde que se registró por primera vez en Brasil en la década de 1990, el biotipo B de la mosca-blanca (Bemisia tabaci Genn., Hemiptera: Aleyrodidae, se reconoce como una importante plaga de la soya (Glycine max L. y es lo que reduce la productividad de estas especies de leguminosas en algunas zonas del pais. Como una alternativa al control químico, el uso de genotipos resistentes representa una herramienta importante para la gestión integrada de plagas (MIP. Este trabajo evaluó el comportamiento de 10 genotipos de soya frente al ataque de la mosca-blanca, por medio de ensayos de atractividad y preferencia para ovipostura en invernaderos y antibiosis en laboratorio. En una prueba de elección multiple, 'IAC-17' fue el menos atractivo para los insectos. En una prueba sin elecci

Factors affecting oviposition of Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) in sweet pepper; Fatores que afetam a oviposicao de Bemisia tabaci (Genn.) biotipo B (Hemiptera: Aleyrodidae) em pimentao

Energy Technology Data Exchange (ETDEWEB)

Lima, Larissa C. de; Campos, Alcebiades R. [UNESP, Ilha Solteira, SP (Brazil). Dept. de Fitossanidade, Engenharia Rural e Solos]. E-mail: lclima@aluno.feis.unesp.br; campos@bio.feis.unesp.br

2008-03-15

Bemisia tabaci (Gen.) biotype B is considered a pest of economical importance for several vegetables. The oviposition behaviour of the while fly was evaluated in sweet pepper plants. The trials were carried out under greenhouse condition and in the Laboratory of Entomology of DEFERS/ UNESP, Campus of Ilha Solteira-SP, with the sweet pepper Magali-R genotype. The effect of plant age on the whitefly oviposition was evaluated in free-choice tests, in plants, 25, 30, 35, 40 and 45- day-old, as egg distribution in the plant and on the leaf blade was evaluated in 35-days-old plants. In a no-choice tests, 35-day-old plants were used to evaluate the effect of the densities of 50, 100, 150, 200 and 250 adults per plant on the number of eggs laid by insects. The silver leaf whitefly preferred to oviposition the third to sixth leaflets, of the medium and superior part of plants of sweet pepper; the leaf blade areas, located in the lobes right and left close the base of the leaf were the preferential site for whitefly oviposition. Older plants, 40- and 45-day-old, were preferentially used for oviposition, and 200 and 250 adults per plant were both enough to lay a number of eggs that allowed to differentiate among sweet pepper genotypes with different whitefly resistance levels. (author)

Bioactivity of indigenous medicinal plants against the cotton whitefly, Bemisia tabaci.

Science.gov (United States)

Hammad, E Abou-Fakhr; Zeaiter, A; Saliba, N; Talhouk, S

2014-01-01

Forty-one methanol extracts of 28 indigenous medicinal plant species were tested for their insecticidal bioactivity against cotton whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), adults and second nymphal instars under controlled conditions. This study is within a bioprospection context, in the form of utilizing local plant species as an alternative in sustainable agriculture development. Eighteen and nine plant extracts caused a significant decrease in number of live adult and nymphal whiteflies, respectively, compared to the control. This is the first report for the potential effect on survival of insects for 22 out of 28 tested medicinal plant species. Whole plant extracts of Ranunculus myosuroudes Boiss. and Kotschy (Ranunculaceae), Achillea damascena L. (Asteraceae), and Anthemis hebronica Boiss. and Kotschy (Asteraceae) and leaf extracts of Verbascum leptostychum DC. (Scrophulariaceae) and Heliotropium rotundifolium Boiss. (Borangiaceae) caused both repellent and toxic effects against the adult and second nymphal instars, respectively. Extracts of leaves and stems of Anthemis scariosa Boiss. (Asteraceae) and Calendula palestina Pers. (Asteraceae) were found to be more bioactive against the adult and nymphal instars, respectively, than extracts of other plant parts, such as flowers. Thus, the bioactive extracts of these medicinal plants have the potential to lower whitefly populations in a comprehensive pest management program in local communities, pending cultivation of these medicinal plant species.

Herbivory by Thrips tabaci

Science.gov (United States)

Deborah M. Kendall

1991-01-01

Herbivory by Thrips tabaci (Lindeman) affects both the bulb yield and phytohormone balance in its major host plant, the onion (Alium cepa L.). Seasonal changes in the susceptibility of onion yield to T. tabaci feeding were examined during the three growth stages of onion; prebulbing, bulbing and sizing (Kendall...

Aspectos biológicos de Chrysoperla externa (Hagen, 1861 (Neuroptera: Chrysopidae alimentada com Bemisia tabaci (Gennadius, 1889 biótipo B (Hemiptera: Aleyrodidae criada em três hospedeiros Biological aspects of Chrysoperla externa (Hagen, 1861 (Neuroptera: Chrysopidae fed on Bemisia tabaci (Gennadius, 1889 biotype B (Hemiptera: Aleyrodidae reared in three hosts

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Cláudio Gonçalves Silva

2004-04-01

Full Text Available Estudaram-se alguns aspectos biológicos de adultos de Chrysoperla externa (Hagen oriundos de larvas alimentadas com ninfas da mosca-branca Bemisia tabaci (Gennadius biótipo B, criadas em folhas de pepino (Cucumis sativus var. caipira, couve (Brassica oleraceae var. acephala e na planta invasora leiteiro (Euphorbia heterophylla. Discos foliares dos hospedeiros contendo ninfas de terceiro e quarto estádios da mosca-branca foram acondicionados em placas de Petri contendo ágar-água a 1%. Em cada placa foi colocada uma larva de C. externa recém-eclodida, onde permaneceram até a emergência dos adultos. Foram avaliados o peso logo após a emergência, os períodos de pré-oviposição, oviposição, efetivo de oviposição, pós-oviposição, número total de ovos produzidos por fêmea e longevidade. Avaliaram-se, também, o período embrionário e a viabilidade dos ovos, coletando-se, uma vez por semana, uma amostra de 10% do total de ovos produzidos no dia, ao longo de todo o período reprodutivo. O peso de machos e fêmeas não diferiu significativamente em função do hospedeiro da presa, sendo em média de 4,7 mg. De maneira geral, adultos de C. externa oriundos de larvas alimentadas com ninfas de B. tabaci biótipo B criadas em leiteiro apresentaram performance inferior em relação àqueles oriundos do pepino e da couve. O período de oviposição foi, em média, de 49,5 dias para o pepino e a couve, e de 31,6 dias para o leiteiro. A produção de ovos foi reduzida em aproximadamente 50% em leiteiro, sendo de 293,8 ovos; no pepino e couve, a média foi de 591,3 ovos. Ninfas de B. tabaci biótipo B criadas em leiteiro causaram uma redução da viabilidade dos ovos de C. externa, que foi 62,8% e 57,7% inferior ao verificado para o pepino e a couve, respectivamente.The aim was to study some biological aspects of adults of Chrysoperla externa (Hagen, from larvae fed on nymphs of third and fourth stages of Bemisia tabaci (Gennadius biotype B

Mortality of Bemisia tabaci biotype B (sternorrhyncha: aleyrodidae adults by aliphatic and aromatic synthetic sucrose esters

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Mariangela Alves

2008-12-01

Full Text Available The B-strain of Bemisia tabaci Gennadius is a key pest of several crops and chemical control is the main control method used by growers, although reduction in efficacy due to insecticide resistance has already been reported. The aim of this work was to investigate the insecticidal effect of an array of synthetic sucrose esters with the aliphatic and aromatic groups on whitefly adults. Sucrose butyrate, caprate, octanoate, palmitate, oleate, octaacetate, phthalate, benzoate, and sucrose diacetate hexaisobutyrate were tested. The solutions were prepared and applied on the adults caught on yellow sticky traps using the Potter spray tower. Long-chains sucrose aliphatic esters were more effective against the silverleaf whiteflies and the highest mortality was obtained with sucrose oleate and sucrose octanoate. Since these compounds were tensoactive, sodium dodecylsulphate was also tested for the comparison but no effect was observed. Sucrose butyrate and other aliphatic and aromatic sucrose polyesters showed negligible effect on the silverleaf whiteflies.O biótipo B de B. tabaci Gennadius tem se destacado como uma praga-chave de diversas culturas. O controle químico tem sido a principal tática de controle utilizada, embora já se tenha observado redução na eficiência dos produtos devido ao desenvolvimento de resistência. Assim, o objetivo do presente trabalho foi avaliar o efeito de diversos ésteres de sacarose com grupos alifáticos ou aromáticos sobre adultos de mosca-branca. Butirato de sacarose, caprato, octanoato, palmitato, oleato, actaacetato, ftlato, benzoato e diacetato hexaisobutirato de sacarose foram testados. Soluções de éster de sacarose foram preparadas e aplicadas sobre adultos capturados em armadilhas adesivas utilizando Torre de Potter. Ésteres alifáticos de sacarose com longas cadeias foram mais efetivos contra mosca-branca e as maiores taxas de mortalidade foram obtidas com oleato e octanoato de sacarose. Uma vez que

Bioactivity of indigenous medicinal plants against the cotton whitefly, Bemisia tabaci

Science.gov (United States)

Hammad, E. Abou-Fakhr; Zeaiter, A.; Saliba, N.; Talhouk, S.

2014-01-01

Abstract Forty-one methanol extracts of 28 indigenous medicinal plant species were tested for their insecticidal bioactivity against cotton whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), adults and second nymphal instars under controlled conditions. This study is within a bioprospection context, in the form of utilizing local plant species as an alternative in sustainable agriculture development. Eighteen and nine plant extracts caused a significant decrease in number of live adult and nymphal whiteflies, respectively, compared to the control. This is the first report for the potential effect on survival of insects for 22 out of 28 tested medicinal plant species. Whole plant extracts of Ranunculus myosuroudes Boiss. and Kotschy (Ranunculaceae), Achillea damascena L. (Asteraceae), and Anthemis hebronica Boiss. and Kotschy (Asteraceae) and leaf extracts of Verbascum leptostychum DC. (Scrophulariaceae) and Heliotropium rotundifolium Boiss. (Borangiaceae) caused both repellent and toxic effects against the adult and second nymphal instars, respectively. Extracts of leaves and stems of Anthemis scariosa Boiss. (Asteraceae) and Calendula palestina Pers. (Asteraceae) were found to be more bioactive against the adult and nymphal instars, respectively, than extracts of other plant parts, such as flowers. Thus, the bioactive extracts of these medicinal plants have the potential to lower whitefly populations in a comprehensive pest management program in local communities, pending cultivation of these medicinal plant species. PMID:25204756

Nuevos registros de especies del género Eretmocerus (Hymenoptera: Aphelinidae, parasitoides de Trialeurodes vaporariorum y el complejo Bemisia tabaci (Hemiptera: Aleyrodidae en Argentina New records of species of the genus Eretmocerus (Hymenoptera: Aphelinidae, parasitoids of Trialeurodes vaporariorum and Bemisia tabaci complex (Hemiptera: Aleyrodidae in Argentina

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Silvia N. López

2008-06-01

Full Text Available El objetivo de este trabajo es dar a conocer nuevos registros y distribuciones de las especies del género Eretmocerus Haldeman, parasitoides de las dos especies de mosca blanca que tienen mayor importancia económica en cultivos hortícolas y ornamentales en Argentina. Una especie de Eretmocerus Haldeman fue hallada parasitando a Trialeurodes vaporariorum (Westwood en Santa Fe y Buenos Aires; por sus caracteres morfológicos, se encuentra en el grupo californicus, cercana a corni Haldeman, podría tratarse de una nueva especie. Asimismo, se amplía la distribución geográfica de Eretmocerus mundus Mercet, enemigo natural del complejo Bemisia tabaci (Gennadius, a las provincias de San Juan y Buenos Aires.The objective of this paper is to report new records of species of the genus Eretmocerus Haldeman, parasitoids of the most important whitefly pest species in vegetables and ornamental crops in Argentina. One species was found parasitizing Trialeurodes vaporariorum (Westwood in Santa Fe and Buenos Aires provinces and it is grouped into californicus group near corni Haldeman, due to its morphological characters. It could be a new species. The known distribution of Eretmocerus mundus Mercet, a parasitoid of Bemisia tabaci (Gennadius, is enlarged to include the provinces of San Juan and Buenos Aires of Argentina.

Estudio de la resistencia a Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae en germoplasma cultivado y silvestre de tomate (Solanum lycopersicum L.

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Yeimy García Valencia

2013-12-01

Full Text Available En la Universidad Nacional de Colombia sede Palmira, en condiciones de campo y casa de malla, se evaluaron por preferencia para oviposición y número de ninfas de mosca blanca (Bemisia tabaci (Gennadius varias accesiones silvestres y poblaciones segregantes de tomate resistentes al pasador del fruto, Neoleucinodes elegantalis (Guenée. Se utilizó un diseño de bloques completos al azar con cuatro repeticiones, donde se evaluaron como variables el número de huevos y de ninfas del insecto por hoja. En cada observación se incluyeron tres hojas del tercio superior, medio e inferior del tallo de la planta. Las poblaciones de mosca blanca fueron muy bajas en los dos primeros ciclos de cultivo (en campo debido, probablemente, a las altas precipitaciones. Estas condiciones no permitieron una selección de materiales resistentes o susceptibles a este insecto. En el tercer ciclo de cultivo, bajo condiciones de casa de malla, no se encontraron diferencias significativas entre los retrocruzamientos respecto al testigo susceptible para la variable preferencia por oviposición. El genotipo 4212P4 presentó el menor número de ninfas, mostrando que tiene posiblemente un mecanismo que le confiere menor atracción para B. tabaci. Se encontró que los genotipos menos preferidos para oviposición y con menor número de ninfas fueron PI 134417, PI 134418 y PI 126449 (Solanum habrochaites var. Glabratum S. Knapp y D. M Spooneer.

Biochemical evaluation of interactions between synergistic molecules and phase I enzymes involved in insecticide resistance in B- and Q-type Bemisia tabaci (Hemiptera: Aleyrodidae).

Science.gov (United States)

Panini, Michela; Tozzi, Francesco; Zimmer, Christoph T; Bass, Chris; Field, Linda; Borzatta, Valerio; Mazzoni, Emanuele; Moores, Graham

2017-09-01

Metabolic resistance is an important consideration in the whitefly Bemisia tabaci, where an esterase-based mechanism has been attributed to pyrethroid resistance and over-expression of the cytochrome P450, CYP6CM1, has been correlated to resistance to imidacloprid and other neonicotinoids. In vitro interactions between putative synergists and CYP6CM1, B and Q-type esterases were investigated, and structure-activity relationship analyses allowed the identification of chemical structures capable of acting as inhibitors of esterase and oxidase activities. Specifically, methylenedioxyphenyl (MDP) moieties with a polyether chain were preferable for optimum inhibition of B-type esterase, whilst corresponding dihydrobenzofuran structures were potent for the Q-esterase variation. Potent inhibition of CYP6CM1 resulted from structures which contained an alkynyl chain with a terminal methyl group. Synergist candidates could be considered for field control of B. tabaci, especially to abrogate neonicotinoid resistance. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Whiteflies: Developing host plant resistance in watermelon from wild sources

Science.gov (United States)

The whitefly (Aleyrodidae) Bemisia tabaci causes serious damage to horticultural crops, including watermelon (Citrullus lanatus var. lanatus) and it is known to transmit many plant viruses. This whitefly is highly polyphagous, with over 1,000 known species, and can adapt to the environment. Yet, th...

Factors affecting oviposition of Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) in sweet pepper

International Nuclear Information System (INIS)

Lima, Larissa C. de; Campos, Alcebiades R.

2008-01-01

Bemisia tabaci (Gen.) biotype B is considered a pest of economical importance for several vegetables. The oviposition behaviour of the while fly was evaluated in sweet pepper plants. The trials were carried out under greenhouse condition and in the Laboratory of Entomology of DEFERS/ UNESP, Campus of Ilha Solteira-SP, with the sweet pepper Magali-R genotype. The effect of plant age on the whitefly oviposition was evaluated in free-choice tests, in plants, 25, 30, 35, 40 and 45- day-old, as egg distribution in the plant and on the leaf blade was evaluated in 35-days-old plants. In a no-choice tests, 35-day-old plants were used to evaluate the effect of the densities of 50, 100, 150, 200 and 250 adults per plant on the number of eggs laid by insects. The silver leaf whitefly preferred to oviposition the third to sixth leaflets, of the medium and superior part of plants of sweet pepper; the leaf blade areas, located in the lobes right and left close the base of the leaf were the preferential site for whitefly oviposition. Older plants, 40- and 45-day-old, were preferentially used for oviposition, and 200 and 250 adults per plant were both enough to lay a number of eggs that allowed to differentiate among sweet pepper genotypes with different whitefly resistance levels. (author)

Direct and indirect impacts of infestation of tomato plant by Myzus persicae (Hemiptera: Aphididae on Bemisia tabaci (Hemiptera: Aleyrodidae.

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Xiao-Ling Tan

Full Text Available The impacts of infestation by the green peach aphid (Myzus persicae on sweetpotato whitefly (Bemisia tabaci settling on tomato were determined in seven separate experiments with whole plants and with detached leaves through manipulation of four factors: durations of aphid infestation, density of aphids, intervals between aphid removal after different durations of infestation and the time of whitefly release, and leaf positions on the plants. The results demonstrated that B. tabaci preferred to settle on the plant leaves that had not been infested by aphids when they had a choice. The plant leaves on which aphids were still present (direct effect had fewer whiteflies than those previously infested by aphids (indirect effect. The whiteflies were able to settle on the plant which aphids had previously infested, and also could settle on leaves with aphids if no uninfested plants were available. Tests of direct factors revealed that duration of aphid infestation had a stronger effect on whitefly landing preference than aphid density; whitefly preference was the least when 20 aphids fed on the leaves for 72 h. Tests of indirect effects revealed that the major factor that affected whitefly preference for a host plant was the interval between the time of aphid removal after infestation and the time of whitefly release. The importance of the four factors that affected the induced plant defense against whiteflies can be arranged in the following order: time intervals between aphid removal and whitefly release > durations of aphid infestation > density of aphids > leaf positions on the plants. In conclusion, the density of aphid infestation and time for which they were feeding influenced the production of induced compounds by tomatoes, the whitefly responses to the plants, and reduced interspecific competition.

Susceptibility of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae to Imidacloprid, Thiamethoxam, Dinotefuran and Flupyradifurone in South Florida

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Hugh A. Smith

2016-10-01

Full Text Available Populations of Bemisa tabaci MEAM1 were established from nineteen locations in south Florida, primarily from commercial tomato fields, and were tested using a cotton leaf petiole systemic uptake method for susceptibility to the nicotinic acetylcholine agonist insecticides imidacloprid, thiamethoxam, dinotefuran and flupyradifurone. Eleven populations produced LC50s for one or more chemicals that were not significantly different from the susceptible laboratory colony based on overlapping fiducial limits, indicating some degree of susceptibility. LC50s more than a 100-fold the laboratory colony were measured in at least one population for each material tested, indicating tolerance. LC50s (ppm from field populations ranged from 0.901–24.952 for imidacloprid, 0.965–24.430 for thiamethoxam, 0.043–3.350 for dinotefuran and 0.011–1.471 for flupyradifurone. Based on overlapping fiducial limits, there were no significant differences in relative mean potency estimates for flupyradifurone and dinotefuran in relation to imidacloprid and thiamethoxam.

Dinâmica populacional de Bemisia tabaci biótipo B em tomate monocultivo e consorciado com coentro sob cultivo orgânico e convencional Population dynamic of Benisua tabaci B biotype in monoculture tomato crop and consortium with coriander in organic and conventional crop system

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Pedro HB Togni

2009-06-01

Full Text Available A mosca-branca Bemisia tabaci Biótipo B (Hemiptera: Aleyrodidae, é um herbívoro de difícil controle devido à alta plasticidade genotípica da espécie. No tomateiro pode causar danos severos principalmente pela transmissão de diversas viroses. O manejo do sistema de produção e o consórcio de culturas podem ter um efeito direto nas populações desse herbívoro, sem que seja necessária a aplicação de inseticidas. Avaliou-se a influência dos sistemas de produção orgânico e convencional e o consórcio tomate-coentro na dinâmica populacional da mosca-branca no campo experimental da Embrapa Hortaliças, de maio a setembro/06. O monitoramento dos adultos da mosca-branca e de seus inimigos naturais foi realizado utilizando-se armadilhas adesivas amarelas fixadas nas bordas e no interior das parcelas experimentais e a amostragem de ninfas foi realizada por observação direta das folhas de tomate no campo. Embora as populações ao redor dos diferentes tratamentos fossem equivalentes, a abundância de adultos de mosca-branca foi significativamente menor nas parcelas de tomate consorciado com coentro, tanto no sistema convencional como orgânico. Apenas o consórcio tomatecoentro em sistema orgânico apresentou redução significativa na quantidade de ninfas por planta em relação aos demais tratamentos. Os inimigos naturais foram significativamente mais abundantes em sistema orgânico e foi verificada uma correlação negativa da abundância dos inimigos naturais e a quantidade de ninfas por planta. A associação tomate-coentro e o manejo orgânico do agroecossistema favoreceram ao controle biológico natural da mosca-branca.Due to its high genotypic plasticity, the control of the silverleaf whitefly Bemisia tabaci B biotype (Hemiptera: Aleyrodidae, is difficult. This insect may cause severe damage to the tomato crop as a vector of several viruses. The management of the production system and the consortium with other crops may have a

Sources of wild germplasm to improve whitefly resistance in commercial watermelon (Citrullus lanatus var. lanatus)

Science.gov (United States)

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

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.

Buprofezin inhibits acetylcholinesterase activity in B-biotype Bemisia tabaci.

Science.gov (United States)

Cottage, Emma L A; Gunning, Robin V

2006-01-01

B-biotype Bemisia tabaci is a severe insect pest worldwide in many ornamental, agricultural, and horticultural industries. Control of this insect is hampered by resistance to many acetylcholinesterase (AChE)-inhibiting insecticides, such as organophosphates and carbamates. Consequently, insect growth regulators such as buprofezin, which act by inhibiting chitin synthesis, are being investigated for use against B-biotype B. tabaci in Australia. This study discusses the effects of buprofezin on B. tabaciAChE.

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 ...

La ruta de señalización del acido salicílico juega un papel importante en la resistencia en tomate a Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) mediada por el gen Mi-1

OpenAIRE

Muñiz, Mariano; Rodriguez, C.I.; Kaloshian, I.; Nombela, Gloria

2009-01-01

Es bien conocido que la resistencia en tomate a Bemisia tabaci (Gennadius), a Macrosiphum euphorbiae (Thomas) y a tres especies de nematodos formadores de nódulos (Meloidogyne spp.) está mediada por el gen Mi-1. Asimismo, está documentado que el ácido salicílico interviene en los mecanismos de resistencia frente a nematodos formadores de nódulos y áfidos. Recientemente se ha descrito que, en Arabidopsis, el biotipo B de B. tabaci induce defensas activadas por este ácido e inhibe las del ácido...

Flatidae (Homoptera: Fulgoroidea) of Indonesia, exclusive of Irian Jaya

NARCIS (Netherlands)

Medler, J.T.

1999-01-01

Taxa of the fulgoroid family Flatidae (Homoptera) occurring in Indonesia exclusive of Irian Jaya are treated. One hundred twenty seven species are recorded under 50 genera. Keys, descriptions, illustrations and collection data are presented. New genera described: Insulume, type species - Insulume

Bemisia tabaci : the whitefly vector of cassava mosaic geminiviruses ...

African Journals Online (AJOL)

The ecology of the Bemisia tabaci/cassava/African cassava mosaic virus (ACMV) pathosystem is reviewed briefly with special attention given to the parameters affecting the pattern of population development of B. tabaci. Significant gaps in our understanding of this system remain, particularly concerning the importance of ...

Studying genetic diversity of whitefly B. tabaci Egyptian isolates in relation to some worldwide isolates

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Inas Farouk Fahmy

2015-06-01

Full Text Available Bemisia tabaci (Gennadius (Hemiptera, Aleyrodidae is considered to be one of the most damaging pests in agriculture, causing severe losses in crops worldwide, affecting the tropical and subtropical regions. Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR was used to assess the genetic diversity between different isolates collected from different regions in Egypt compared with some other worldwide isolates of this insect pest. Out of 12 primers 8 primers from Operon technology have shown to differentiate between 13 collected B. tabaci samples from all over Egypt and some other samples collected from different countries with two other populations representing biotypes A and B collected from the US used for biotype demarcation. Using 13 insect samples, RAPD analysis has produced a total number of 72 markers; about 68 polymorphic markers were revealed. The total number of bands obtained for each primer ranged from 4 to 14 within an average of 9 bands per primer. Of the pair wise combination among fifteen populations Ismailia population showed the highest similarity index (0.947, while US biotype A scored the lowest similarity index (0.326. Two major clusters were formed from the UPGMA dendrogram, which was constructed based on Dice similarity coefficient. RAPD-PCR screening demarcated the whitefly population based on the host species and genetic biotypes. Two major clusters have been revealed as A and B with two other minor clusters A1, A2, and B1, B2. Most of the samples collected from Egypt were clustered together in a minor cluster named A1. A1 group is divided into two sub-groups. A1a comprises the populations from Beni-Sweif in Upper Egypt, Ismailia, Kalyobia, El-Fayoum, Tanta, Kafr El-Sheikh, Alexandria, and A1b comprises Spain and Sudan. Group A1a is clustered together based on their host which belongs to the Cucurbitaceae family while Alexandria was separated individually based on its host which is cauliflower. Through

Plano de amostragem do biótipo B de Bemisia tabaci na cultura do pepino

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Moura Marcelo Fialho de

2003-01-01

Full Text Available A adoção de programas de manejo integrado de pragas permite reduzir a aplicação de inseticidas e os planos convencionais de amostragem representam o ponto inicial na geração desses programas. Assim, o objetivo deste trabalho foi determinar plano de amostragem convencional para o biótipo B da mosca-branca Bemisia tabaci Genn. (Hemiptera: Aleyrodidae na cultura do pepino. Foram avaliadas as densidades de ninfas e de adultos em dez lavouras comerciais de pepino, Tocantins, MG, estudando nove sistemas amostrais formados pela combinação de três técnicas (batida de folha em bandeja de plástico branco, contagem direta dos insetos na face inferior da folha e coleta de folha em sacola de plástico e três unidades amostrais (folha do terço apical, mediano ou basal do espaldeiramento. A contagem direta em folha do terço basal foi o sistema com maior precisão econômica na amostragem de ninfas, mas não possibilitou a geração de plano de amostragem praticável. As batidas, em bandeja, de folha dos terços apicais, medianos ou basais do espaldeiramento foram os sistemas economicamente mais precisos na amostragem de adultos. Desses, apenas a batida de folha do terço mediano em bandeja gerou plano de amostragem praticável, sendo que este plano é composto de 196 amostras/lavoura.

HOST PLANT PREFERENCES OF BEMISIA TABACI GENNADIUS

Institute of Scientific and Technical Information of China (English)

JINGYing; HUANGJian; MARui-yan; HANJu-cai

2003-01-01

The preferences of Bemisia tabaci Gennadius for five host plants:poinsettia, tomato, cabbage,sweet potato and flowering Chinese cabbage, was tested using a Y-tube olfactometer and a desiccator in the labo-ratory. The results show that B. tabaci adults were attracted by the odors of the five plants. The order of prefer-ence was poinsettia > flowering Chinese cabbage > sweet potato > cabbage > tomato. Preference was extremely sig-nificant between poinsettia and the other four plants, and between flowering Chinese cabbage, cabbage and toma-to. There was no significant difference in preference for flowering Chinese cabbage and sweet potato, sweet pota-to, cabbage and tomato or between cabbage and tomato.

Investigating contact toxicity of Geranium and Artemisia essential oils on Bemisia tabaci Gen.

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Fatemeh Yarahmadi

2013-04-01

Full Text Available Objective: Sweet potato whitefly, Bemisia tabaci Gen. (B. tabaci, is one of the most important pests of various greenhouse crops in Iran. Nowadays, chemical insecticides are broadly used for control of the pests that causes risk to consumer's health. For the first time, contact toxicity of Pelargonium roseum Andrews and Artemisia sieberi Besser essential oils on B. tabaci and its possible application against the whitefly was evaluated in 2012. Materials and Methods: Essential oil with concentrations of 2500, 1250, 125, and 12 ppm were used. Infested leaves of greenhouse cucumber were treated by mentioned concentrations. After 24 hours, mortality of B. tabaci was recorded and compared after correcting by Abbot's formula. Results: Results showed that all concentrations of the essential oil could significantly reduce population of B. tabaci compared with the control treatment. Phytotoxicity of the treated leaves were recorded after 24, 48, and 72 hours and compared with the control. Concentrations of 2500, 1250, and 125 ppm caused severe phytotoxicity on greenhouse cucumber leaves and therefore are not suitable for greenhouse application. Phytotoxicity of 12 ppm was relatively low. Conclusions: This data implicated suitable protective effects of the essential oils to the pest infestation. Therefore, essential oils distillated from Geranium and Artemisia could be applied to control B. tabaci in greenhouse cucumber at V/V 12 ppm.

Genetic diversity of Bemisia tabaci (Genn. Populations in Brazil revealed by RAPD markers

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L.H.C. Lima

2002-01-01

Full Text Available Bemisia tabaci (Genn. was considered a secondary pest in Brazil until 1990, despite being an efficient geminivirus vector in beans and soybean. In 1991, a new biotype, known as B. tabaci B biotype (=B. argentifolii was detected attacking weed plants and causing phytotoxic problems in Cucurbitaceae. Nowadays, B. tabaci is considered one of the most damaging whitefly pests in agricultural systems worldwide that transmits more than 60 different plant viruses. Little is known about the genetic variability of these populations in Brazil. Knowledge of the genetic variation within whitefly populations is necessary for their efficient control and management. The objectives of the present study were to use RAPD markers (1 to estimate the genetic diversity of B. tabaci populations, (2 to study the genetic relationships among B. tabaci biotypes and two other whitefly species and (3 to discriminate between B. tabaci biotypes. A sample of 109 B. tabaci female individuals obtained from 12 populations in Brazil were analyzed and compared to the A biotype from Arizona (USA and B biotype from California (USA and Paraguay. Trialeurodes vaporariorum and Aleurodicus cocois samples were also included. A total of 72 markers were generated by five RAPD primers and used in the analysis. All primers produced RAPD patterns that clearly distinguished the Bemisia biotypes and the two other whitefly species. Results also showed that populations of the B biotype have considerable genetic variability. An average Jaccard similarity of 0.73 was observed among the B biotype individuals analyzed. Cluster analysis demonstrated that, in general, Brazilian biotype B individuals are scattered independently in the localities where samples were collected. Nevertheless, some clusters were evident, joining individuals according to the host plants. AMOVA showed that most of the total genetic variation is found within populations (56.70%, but a significant portion of the variation is found

Cross-resistance, inheritance and biochemical mechanisms of imidacloprid resistance in B-biotype Bemisia tabaci.

Science.gov (United States)

Wang, Zhenyu; Yao, Mingde; Wu, Yidong

2009-11-01

The B-type Bemisia tabaci (Gennadius) has become established in many regions in China, and neonicotinoids are extensively used to control this pest. Imidacloprid resistance in a laboratory-selected strain of B-type B. tabaci was characterised in order to provide the basis for recommending resistance management tactics. The NJ-Imi strain of B-type B. tabaci was selected from the NJ strain with imidacloprid for 30 generations. The NJ-Imi strain exhibited 490-fold resistance to imidacloprid, high levels of cross-resistance to three other neonicotinoids, low levels of cross-resistance to monosultap, cartap and spinosad, but no cross-resistance to abamectin and cypermethrin. Imidacloprid resistance in the NJ-Imi strain was autosomal and semi-dominant. It is shown that enhanced detoxification mediated by cytochrome-P450-dependent monooxygenases contributes to imidacloprid resistance to some extent in the NJ-Imi strain. Results from synergist bioassays and cross-resistance patterns indicated that target-site insensitivity may be involved in imidacloprid resistance in the NJ-Imi strain of B. tabaci. Although oxidative detoxification mediated by P450 monooxygenases is involved in imidacloprid resistance in the NJ-Imi strain of B-type B. tabaci, target-site modification as an additional resistance mechanism cannot be ruled out. Considering the high risk of cross-resistance, neonicotinoids should be regarded as a single group when implementing an insecticide rotation scheme in B. tabaci control. (c) 2009 Society of Chemical Industry.

Feasible sampling plan for Bemisia tabaci control decision-making in watermelon fields.

Science.gov (United States)

Lima, Carlos Ho; Sarmento, Renato A; Pereira, Poliana S; Galdino, Tarcísio Vs; Santos, Fábio A; Silva, Joedna; Picanço, Marcelo C

2017-11-01

The silverleaf whitefly Bemisia tabaci is one of the most important pests of watermelon fields worldwide. Conventional sampling plans are the starting point for the generation of decision-making systems of integrated pest management programs. The aim of this study was to determine a conventional sampling plan for B. tabaci in watermelon fields. The optimal leaf for B. tabaci adult sampling was the 6 th most apical leaf. Direct counting was the best pest sampling technique. Crop pest densities fitted the negative binomial distribution and had a common aggregation parameter (K common ). The sampling plan consisted of evaluating 103 samples per plot. This sampling plan was conducted for 56 min, costing US$ 2.22 per sampling and with a 10% maximum evaluation error. The sampling plan determined in this study can be adopted by farmers because it enables the adequate evaluation of B. tabaci populations in watermelon fields (10% maximum evaluation error) and is a low-cost (US$ 2.22 per sampling), fast (56 min per sampling) and feasible (because it may be used in a standardized way throughout the crop cycle) technique. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Effects of Three Insect Growth Regulators on Encarsia formosa (Hymenoptera: Aphelinidae), an Endoparasitoid of Bemisia tabaci (Hemiptera: Aleyrodidae).

Science.gov (United States)

Wang, Q L; Liu, T-X

2016-12-01

Insect growth regulators (IGRs) disrupt the normal activity of the endocrine or hormone system of insects, affecting the development, reproduction, or metamorphosis of the target insects, and normally causing less detrimental effects to beneficial insects. The effects of three IGRs (pyriproxyfen, fenoxycarb, and buprofezin) on Encarsia formosa Gahan, an endoparasitoid of whiteflies, were determined using B. tabaci as a host. We assessed the effects of the IGRs on parasitoid's larval development, pupation, emergence, and contact effects of the dry residues on plant leaf and glass vial surface on adult mortality and parasitism. When the three IGRs were applied at larval stage, no or few larvae pupated in the pyriproxyfen treatments and the highest concentration of fenoxycarb, and a majority of larvae pupated in the buprofezin treatments; of those pupated, 62.3-88.1% became adults. When the IGRs were applied at the pupal stage, 2.3-17.5% developed to adults in the pyriproxyfen treatments, 59.7-89.0% in the fenoxycarb treatments, and 58.4-83.6% in the buprofezin treatments. The leaf residues of the IGRs had no appreciable effects on adults, whereas the residues on glass vial caused significantly lower adult survival than on plant leaves. The residues of pyriproxyfen and fenoxycarb slightly reduced parasitism as compared with buprofezin and controls. However, the rates of parasitoids that became adults were significantly lower, especially in the pyriproxyfen treatments. According to the standards of International Organization of Biological Control (IOBC), pyriproxyfen was harmful, while fenoxycarb and buprofezin were slightly or moderately harmful to larvae and harmless to E. formosa pupae. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Genome-wide analysis of ATP-binding cassette (ABC) transporters in the sweetpotato whitefly, Bemisia tabaci.

Science.gov (United States)

Tian, Lixia; Song, Tianxue; He, Rongjun; Zeng, Yang; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

2017-04-26

ABC transporter superfamily is one of the largest and ubiquitous groups of proteins. Because of their role in detoxification, insect ABC transporters have gained more attention in recent years. In this study, we annotated ABC transporters from a newly sequenced sweetpotato whitefly genome. Bemisia tabaci Q biotype is an emerging global invasive species that has caused extensive damages to field crops as well as ornamental plants. A total of 55 ABC transporters containing all eight described subfamilies (A to H) were identified in the B. tabaci Q genome, including 8 ABCAs, 3 ABCBs, 6 ABCCs, 2 ABCDs, 1 ABCE, 3 ABCFs, 23 ABCGs and 9 ABCHs. In comparison to other species, subfamilies G and H in both phloem- and blood-sucking arthropods are expanded. The temporal expression profiles of these 55 ABC transporters throughout B. tabaci developmental stages and their responses to imidacloprid, a neonicotinoid insecticide, were investigated using RNA-seq analysis. Furthermore, the mRNA expression of 24 ABC transporters (44% of the total) representing all eight subfamilies was confirmed by the quantitative real-time PCR (RT-qPCR). Furthermore, mRNA expression levels estimated by RT-qPCR and RNA-seq analyses were significantly correlated (r = 0.684, p analysis of the entire repertoire of ABC transporters in B. tabaci. The identification of these ABC transporters, their temporal expression profiles during B. tabaci development, and their response to a neonicotinoid insecticide lay the foundation for functional genomic understanding of their contribution to the invasiveness of B. tabaci.

Toxicity of insecticides to the sweetpotato whitefly (Hemiptera: Aleyrodidae) and its natural enemies.

Science.gov (United States)

Bacci, Leandro; Crespo, André L B; Galvan, Tederson L; Pereira, Eliseu J G; Picanço, Marcelo C; Silva, Gerson A; Chediak, Mateus

2007-07-01

Efficient chemical control is achieved when insecticides are active against insect pests and safe to natural enemies. In this study, the toxicity of 17 insecticides to the sweetpotato whitefly, Bemisia tabaci (Gennadius), and the selectivity of seven insecticides to natural enemies of this insect pest were evaluated. To determine the insecticide toxicity, B. tabaci adults were exposed to abamectin, acephate, acetamiprid, cartap, imidacloprid, malathion, methamidophos, bifenthrin, cypermethrin, deltamethrin, esfenvalerate, fenitrothion, fenpropathrin, fenthion, phenthoate, permethrin and trichlorphon at 50 and 100% of the field rate (FR), and to water (untreated control). To determine the insecticide selectivity, adults of Encarsia sp., Acanthinus sp., Discodon sp. and Lasiochilus sp. were exposed to abamectin, acephate, acetamiprid, cartap, imidacloprid, malathion and methamidophos at 50 and 100% FR, and to water. Groups of each insect species were exposed to kale leaves preimmersed in each treatment under laboratory conditions. Mortality of exposed individuals was recorded 24 h after treatment. Cartap and imidacloprid at 50 and 100% FR and abamectin and acetamiprid at 100% FR showed insecticidal activity to B. tabaci adults. Abamectin at 50 and 100% FR was the least insecticidal compound to the natural enemies Acanthinus sp., Discodon sp. and Lasiochilus sp. The present results suggest that abamectin at 100% FR may decrease B. tabaci field populations but can still be harmless to predators. Implications of these results within an integrated pest management context are discussed. Copyright (c) 2007 Society of Chemical Industry.

Survival of Bemisia tabaci and activity of plant defense-related enzymes in genotypes of Capsicum annuum L.

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Luis Latournerie-Moreno

2015-03-01

Full Text Available The whitefly Bemisia tabaci (Gennadius, 1889 is a major plant pest of horticultural crops from the families Solanaceae, Fabaceae and Cucurbitaceae in Neotropical areas. The exploration of host plant resistance and their biochemical mechanisms offers an excellent alternative to better understand factors affecting the interaction between phytophagous insect and host plant. We evaluated the survival of B. tabaci in landrace genotypes of Capsicum annuum L., and the activity of plant defense-related enzymes (chitinase, polyphenoloxidase, and peroxidase. The landrace genotypes Amaxito, Tabaquero, and Simojovel showed resistance to B. tabaci, as we observed more than 50% nymphal mortality, while in the commercial susceptible genotype Jalapeño mortality of B. tabaci nymphs was not higher than 20%. The activities of plant defense-related enzymes were significantly different among pepper genotypes (P < 0.05. Basal activities of chitinase, polyphenoloxidase and peroxidase were significantly lower or equal in landrace genotypes than that of the commercial genotype Jalapeño. The activity of plant enzymes was differential among pepper genotypes (P < 0.05. For example, the activity of chitinase enzyme generally was higher in non-infested plants with B. tabaci than those infested. Instead polyphenoloxidase ('Amaxito' and 'Simojovel' and peroxidase enzymes activities ('Tabaquero' increased in infested plants (P < 0.05. We conclude that basal activities of plant defense-related enzymes could be act through other mechanism plant induction, since plant defense-related enzymes showed a different induction response to B. tabaci. We underlined the role of polyphenoloxidase as plant defense in the pepper genotype Simojovel related to B. tabaci.

Lack of resistance development in Bemisia tabaci to Isaria fumosorosea after multiple generations of selection

Science.gov (United States)

Gao, Tianni; Wang, Zhaolei; Huang, Yü; Keyhani, Nemat O.; Huang, Zhen

2017-02-01

The emergence of insecticide resistant insect pests is of significant concern worldwide. The whitefly, Bemisia tabaci, is an important agricultural pest and has shown incredible resilience developing resistance to a number of chemical pesticides. Entomopathogenic fungi such as Isaria fumosorosea offer an attractive alternative to chemical pesticides for insect control, and this fungus has been shown to be an effective pathogen of B. tabaci. Little is known concerning the potential for the development of resistance to I. fumosorosea by B. tabaci. Five generations of successive survivors of B. tabaci infected by I. fumosorosea were assayed with I. fumosorosea. No significant differences in susceptibility to I. fumosorosea, number of ovarioles, or ovipostioning were seen between any of the generations tested. Effects of I. fumosorosea and cell-free ethyl acetate fractions derived from the fungus on the B. tabaci fat body, ovary, and vitellogenin were also investigated. These data revealed significant deformation and degradation of ovary tissues and associated vitellogenin by the fungal mycelium as well as by cell-free ethyl acetate fungal extracts. These data indicate the lack of the emergence of resistance to I. fumosorosea under the conditions tested and demonstrate invasion of the insect reproductive tissues during fungal infection.

Biological parameters of onion thrips, Thrips tabaci Lindeman on onion cultivars

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Moraiet Maher Ahmed

2017-06-01

Full Text Available Biological parameters of the onion thrips, Thrips tabaci Lindeman were studied on the following onion (Allium cepa L. cultivars: Nasik Red Plus N-53, Onion Dr-301 (Krishna, Onion White, and Nasik Red, at 25±1°C and 65±5% RH. Significant (p < 0.05 differences were found in the life stages and fertility life tables on different cultivars except in the pupal stages. More information about the biological parameters of T. tabaci on onion cultivars can help in designing Integrated Pest Management programs for onion thrips.

Whitefly Pest Species (Homoptera: Aleyrodidae) on Citrus Trees

OpenAIRE

Katja Žanić; Sonja Kačić; Miro Katalinić

2000-01-01

Today, the Citrus whitefly, Dialeurodes citri (Ashmead), is a very important pest on all Citrus species throughout the citrus growing areas in Croatia. It causes direct damage by sucking the plant juice from the leaves. Furthermore, immatures excrete honeydew that stimulates sooy mold. The presence of sooty mold on contaminated leaves interferes with the photosynthesis of plants. Citrus fruits coated by sooty mold lose its market value. Because Dialeurodes citri is poorly known in Croatia, th...

Effectiveness of BPMC Application against Bemisia tabaci (Gennadius Population and CMMV Disease Incidence on Soybean

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Wartono Wartono

2015-09-01

Full Text Available Control of whitefly (Bemisia tabaci (Gennadius is the starting point in suppressing the CMMV disease (cowpea mild mottle virus. This study aims to determine the influence of applications BPMC (500 g a.i./l against B. tabaci populations and disease incidence of CMMV on soybean plants. Research was conducted in the field with randomized complete block design consisting of 5 treatments i.e. five concentration levels: 0.75, 1.50,2.25, and 3.00 ml/l including control (untreated with 5 replications. The results showed that BPMC is effective in suppressing the adult population of B. tabaci and disease incidence of CMMV.

Estadísticos vitales de Bemisia tabaci biotipo B en frijol e interacción con el parasitoide Amitus fuscipennis: Life history parameters and absence of hostparasitoid interaction with Amitus fuscipennis Bemisia tabaci biotype B in bean

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María del Rosario Manzano Martínez

2009-10-01

Full Text Available Se determinaron los estadísticos vitales de la mosca blanca Bemisia tabaci biotipo B en condiciones de laboratorio (26 °C ± 2 °C y 80 ± 5 % de HR en fríjol cultivar ICA-Pijao. Los valores promedios fueron: longevidad 34 ± 1.64 días, fecundidad de 211.4 ± 15.1 huevos/hembra y tasa de oviposición de 6.1 ± 0.28 huevos/día. La tasa neta reproductiva fue de 137.8. El tiempo generacional de 43.8 días y la tasa intrínseca de crecimiento poblacional (r m de 0.125. Estos valores son coincidentes con los reportados en la literatura e indicaron la utilidad del frijol (Phaseolus vulgaris L ICA-Pijao para la multiplicación de B. tabaci. No se logró la reproducción de Amitus fuscipennis en B. tabaci. Estudios de comportamiento mostraron que el parasitoide permaneció solo 617.3 seg en promedio en foliolos infestados con la mosca blanca, la mayor parte del tiempo lo invirtió en caminar (46.4%, limpiarse el cuerpo (35.6% y permanecer quieta (16.7%. A. fuscipennis solo tocó una vez accidentalmente una ninfa de B. tabaci, pero no la examinó con las antenas ni la ovipositó. Los resultados indican que A. fuscipennis no es un enemigo natural potencial de B. tabaci biotipo B.Life-history parameters of the whitefly Bemisia tabaci biotipo B were determined at laboratory conditions at 26 °C ± 2 °C y 80 ± 5 % de RH on bean ICA-Pijao. Mean longevity of the whitefly was 34 ± 1,64 days, mean total fecundity was 211,4 ± 15,1 eggs per female with a daily oviposition rate of 6,1 ± 0,28 eggs per day. Net reproduction rate was 137,8. Generation Time was 43,8 days and the intrinsic rate of population increase r m was 0,125. These values are according to previous ones reported and support usefulness of ICA-Pijao bean for B. tabaci rearing. It was not possible to rear Amitus fuscipennis from B. tabaci. Behaviour studies showed that the parasitoid stayed only average 617,3 s on whitefly infested leaflets. It invested most of the time walking (46

Compatibility of the entomopathogenic fungus Lecanicillium muscarium and insecticides for eradication of sweetpotato whitefly, Bemisia tabaci.

Science.gov (United States)

Cuthbertson, Andrew G S; Walters, Keith F A; Deppe, Carola

2005-08-01

The compatibility of the entomopathogenic fungus Lecanicillium muscarium and chemical insecticides used to control the second instar stages of the sweetpotato whitefly, Bemisia tabaci, was investigated. The effect on spore germination of direct exposure for 24 h to the insecticides imidacloprid, buprofezin, teflubenzuron and nicotine was determined. Only exposure to buprofezin was followed by acceptable spore germination. However, all chemicals significantly reduced spore germination when compared to a water control. Infectivity of L. muscarium in the presence of dry residues of buprofezin, teflubenzuron and nicotine (imidacloprid is a systemic pesticide) on foliage were also investigated. No significant detrimental effects on the level of control of B. tabaci was recorded when compared with fungi applied to residue free foliage on either tomato or verbena plants. Fungi in combination with imidacloprid gave higher B. tabaci mortality on verbena foliage compared to either teflubenzuron or nicotine and fungi combinations. Use of these chemical insecticides with L. muscarium in integrated control programmes for B. tabaci is discussed.

Pyrosequencing the Bemisia tabaci transcriptome reveals a highly diverse bacterial community and a robust system for insecticide resistance.

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Wen Xie

Full Text Available BACKGROUND: Bemisia tabaci (Gennadius is a phloem-feeding insect poised to become one of the major insect pests in open field and greenhouse production systems throughout the world. The high level of resistance to insecticides is a main factor that hinders continued use of insecticides for suppression of B. tabaci. Despite its prevalence, little is known about B. tabaci at the genome level. To fill this gap, an invasive B. tabaci B biotype was subjected to pyrosequencing-based transcriptome analysis to identify genes and gene networks putatively involved in various physiological and toxicological processes. METHODOLOGY AND PRINCIPAL FINDINGS: Using Roche 454 pyrosequencing, 857,205 reads containing approximately 340 megabases were obtained from the B. tabaci transcriptome. De novo assembly generated 178,669 unigenes including 30,980 from insects, 17,881 from bacteria, and 129,808 from the nohit. A total of 50,835 (28.45% unigenes showed similarity to the non-redundant database in GenBank with a cut-off E-value of 10-5. Among them, 40,611 unigenes were assigned to one or more GO terms and 6,917 unigenes were assigned to 288 known pathways. De novo metatranscriptome analysis revealed highly diverse bacterial symbionts in B. tabaci, and demonstrated the host-symbiont cooperation in amino acid production. In-depth transcriptome analysis indentified putative molecular markers, and genes potentially involved in insecticide resistance and nutrient digestion. The utility of this transcriptome was validated by a thiamethoxam resistance study, in which annotated cytochrome P450 genes were significantly overexpressed in the resistant B. tabaci in comparison to its susceptible counterparts. CONCLUSIONS: This transcriptome/metatranscriptome analysis sheds light on the molecular understanding of symbiosis and insecticide resistance in an agriculturally important phloem-feeding insect pest, and lays the foundation for future functional genomics research of the

Phylogenetic analysis and inflow route of Tomato yellow leaf curl virus (TYLCV) and Bemisia tabaci in Korea.

Science.gov (United States)

Lee, Hyejung; Song, Woogeun; Kwak, Hae-Ryun; Kim, Jae-Deok; Park, Jungan; Auh, Chung-Kyoon; Kim, Dae-Hyun; Lee, Kyeong-Yeoll; Lee, Sukchan; Choi, Hong-Soo

2010-11-01

Tomato yellow leaf curl virus (TYLCV) is a member of the genus Begomovirus of the family Geminiviridae, members of which are characterized by closed circular single-stranded DNA genomes of 2.7-2.8 kb in length, and include viruses transmitted by the Bemisia tabaci whitefly. No reports of TYLCV in Korea are available prior to 2008, after which TYLCV spread rapidly to most regions of the southern Korean peninsula (Gyeongsang-Do, Jeolla-Do and Jeju-Do). Fifty full sequences of TYLCV were analyzed in this study, and the AC1, AV1, IR, and full sequences were analyzed via the muscle program and bayesian analysis. Phylogenetic analysis demonstrated that the Korea TYLCVs were divided into two subgroups. The TYLCV Korea 1 group (Masan) originated from TYLCV Japan (Miyazaki) and the TYLCV Korea 2 group (Jeju/Jeonju) from TYLCV Japan (Tosa/Haruno). A B. tabaci phylogenetic tree was constructed with 16S rRNA and mitochondria cytochrome oxidase I (MtCOI) sequences using the muscle program and MEGA 4.0 in the neighbor-joining algorithm. The sequence data of 16S rRNA revealed that Korea B. tabaci was closely aligned to B. tabaci isolated in Iran and Nigeria. The Q type of B. tabaci, which was originally identified as a viruliferous insect in 2008, was initially isolated in Korea as a non-viruliferous insect in 2005. Therefore, we suggest that two TYLCV Japan isolates were introduced to Korea via different routes, and then transmitted by native B. tabaci.

Tomato yellow vein streak virus: relationship with Bemisia tabaci biotype B and host range Tomato yellow vein streak virus: interação com a Bemisia tabaci biótipo B e gama de hospedeiros

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Ana Carolina Firmino

2009-12-01

Full Text Available The Tomato yellow vein streak virus (ToYVSV is a putative species of begomovirus, which was prevalent on tomato crops in São Paulo State, Brazil, until 2005. The objectives of this study were to evaluate the interaction between ToYVSV and its vector Bemisia tabaci biotype B and to identify alternative hosts for the virus. The minimum acquisition and inoculation access periods of ToYVSV by B. tabaci were 30 min and 10 min, respectively. Seventy five percent of tomato-test plants were infected when the acquisition and inoculation access periods were 24 h. The latent period of the virus in the insect was 16 h. The ToYVSV was retained by B. tabaci until 20 days after acquisition. First generation of adult whiteflies obtained from viruliferous females were virus free as shown by PCR analysis and did not transmit the virus to tomato plants. Out of 34 species of test-plants inoculated with ToYVSV only Capsicum annuum, Chenopodium amaranticolor, C. quinoa, Datura stramonium, Gomphrena globosa, Nicotiana clevelandii and N. tabacum cv. TNN were susceptible to infection. B. tabaci biotype B was able to acquire the virus from all these susceptible species, transmitting it to tomato plants.O Tomato yellow vein streak virus (ToYVSV é uma espécie putativa de begomovirus que infecta o tomateiro (Solanum lycopersicon em diversas regiões do Brasil onde se cultiva essa solanácea, sendo a espécie prevalente no estado de São Paulo até 2005. Estudou-se a interação do ToYVSV com a Bemisia tabaci biótipo B e identificaram-se hospedeiras alternativas deste vírus. Os períodos de acesso mínimo de aquisição (PAA e de inoculação (PAI foram de 30 min e 10 min, respectivamente. A porcentagem de plantas infectadas chegou até cerca de 75% após um PAA e PAI de 24 h. O período de latência do vírus no vetor foi de 16 horas. O ToYVSV foi retido pela B. tabaci até 20 dias após a aquisição do vírus. Não foi detectada transmissão do vírus para prog

Oviposition behavior of the silver leaf whitefly Bemisia tabaci biotype B on tomato

International Nuclear Information System (INIS)

Vendramim, Jose D.; Souza, Antonio P. de; Ongarelli, Maria das G.

2009-01-01

The objective of this work was to evaluate the influence of the leaf surface, the insect geotropic behavior and the type of foliar trichome on Bemisia tabaci (Genn.) biotype B oviposition on tomato leaves. Bemisia tabaci females were confined in acrylic boxes in which tomato leaflets were fixed at the bottom and top part of the boxes to allow insects to access the leaf surface to be tested (adaxial and/or abaxial) in both no-choice and free choice tests. Oviposition was always higher when the leaf was offered at the top of the box and preferably at the abaxial leaf surface. The effects of leaf trichomes (glandular and non glandular) on B. tabaci oviposition was evaluated by offering the abaxial surface of tomato leaflets to females after a 70% ethanol wash to remove glandular exsudates against a control treatment (without a ethanol wash). Oviposition was concentrated mostly near to non glandular trichomes, showing whitefly females can discriminate among the trichomes. (author)

Transcriptomic dissection of sexual differences in Bemisia tabaci, an invasive agricultural pest worldwide.

Science.gov (United States)

Xie, Wen; Guo, Litao; Jiao, Xiaoguo; Yang, Nina; Yang, Xin; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

2014-02-14

Sex difference involving chromosomes and gene expression has been extensively documented. In this study, the gender difference in the sweetpotato whitefly Bemisia tabaci was investigated using Illumina-based transcriptomic analysis. Gender-based RNAseq data produced 27 Gb reads, and subsequent de novo assembly generated 93,948 transcripts with a N50 of 1,853 bp. A total of 1,351 differentially expressed genes were identified between male and female B. tabaci, and majority of them were female-biased. Pathway and GO enrichment experiments exhibited a gender-specific expression, including enriched translation in females, and enhanced structural constituent of cuticle in male whiteflies. In addition, a putative transformer2 gene (tra2) was cloned, and the structural feature and expression profile of tra2 were investigated. Sexually dimorphic transcriptome is an uncharted territory for the agricultural insect pests. Molecular understanding of sex determination in B. tabaci, an emerging invasive insect pest worldwide, will provide potential molecular target(s) for genetic pest control alternatives.

Lack of resistance development in Bemisia tabaci to Isaria fumosorosea after multiple generations of selection

OpenAIRE

Tianni Gao; Zhaolei Wang; Yü Huang; Nemat O. Keyhani; Zhen Huang

2017-01-01

The emergence of insecticide resistant insect pests is of significant concern worldwide. The whitefly, Bemisia tabaci, is an important agricultural pest and has shown incredible resilience developing resistance to a number of chemical pesticides. Entomopathogenic fungi such as Isaria fumosorosea offer an attractive alternative to chemical pesticides for insect control, and this fungus has been shown to be an effective pathogen of B. tabaci. Little is known concerning the potential for the dev...

Bemisia tabaci : the whitefly vector of cassava mosaic geminiviruses ...

African Journals Online (AJOL)

Significant gaps in our understanding of this system remain, particularly concerning the importance of interactions of B. tabaci with other arthropod pests of cassava and the influence of ecological factors such as soil nutrients indirectly through their effects upon cassava. An holistic ecological approach to future work on B.

Hubungan Antara Populasi Kutu Kebul (bemisia tabaci Genn) dan Keterjadian Penyakit Kuning Pada Tanaman Cabai (Capsicum annum l.) di Dataran Rendah

OpenAIRE

Singarimbun, Monica Angela

2016-01-01

Yellow disease is one of disease that attack chili plants caused by pests vector B. Tabaci. The objective of this research was to find out the relationship between population of B. Tabaci and yellow disease incidence of chili that was conducted in lowland. This research was conducted in lowland in March – April 2016. The result showed that the population of B. tabaci affected the yellow disease incidence correlation value 0,866. The average percentage of the yellow disease incidence in lowlan...

Migration, trapping and local dynamics of whiteflies (Homoptera: Aleyrodidae)

DEFF Research Database (Denmark)

Riis, Lisbeth; Nachman, Gösta

2006-01-01

to population growth. 4 A model for changes in whitefly density during an entire bean (Phaseolus vulgaris L.) crop cycle, including an immigration parameter, was also developed. 5 Non-attractant window traps surrounding an annual field crop were assumed to intercept whiteflies immigrating into and emigrating...

Resposta à mosca-branca (Bemisia tabaci e ao Tomato severe rugose virus de acessos de Solanum subgênero Leptostemonum Reaction to whitefly (Bemisia tabaci and Tomato severe rugose virus of Solanum subgenus Leptostemonum accessions

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Miguel Michereff-Filho

2012-09-01

Full Text Available A mosca-branca (Bemisia tabaci e a infecção por espécies de Begomovirus são dois graves problemas fitossanitários que afetam a produção e qualidade do tomateiro (Solanum lycopersicum e de outras solanáceas de importância econômica. O presente trabalho foi conduzido sob condições controladas, em casa de vegetação, visando avaliar a resposta ao Tomato severe rugose virus (ToSRV e à mosca-branca (B. tabaci biótipo B de 36 acessos de espécies relacionadas ao gênero Solanum subgênero Leptostemonum (= grupo das solanáceas providas de espinhos. A inoculação de ToSRV foi realizada em mudas (43 dias após o semeio utilizando-se um colônia virulífera de B. tabaci biótipo B. Duas cultivares de tomateiro foram incluídas como testemunhas suscetíveis. A avaliação ao ToSRV foi feita de acordo com uma escala de severidade de sintomas e a presença de infecção sistêmica foi verificada via reação em cadeia da polimerase (PCR com 'primers' universais para espécies de Begomovirus. A maioria dos acessos apresentou uma resposta do tipo resistência ou quase imunidade ao ToSRV, não apresentando sintomas evidentes e nenhum indício de infecção sistêmica ou acumulação viral. Um grupo reduzido de acessos de S. stramonifolium, S. asperolanatum e S. jamaiscense apresentou uma resposta do tipo tolerância, caracterizada por baixa acumulação viral e sintomas suaves. O acesso S. mammosum 'CNPH 035', embora tolerante, foi o único que apresentou sintomas mais evidentes de infecção viral e acumulação de ToSRV. O mesmo grupo de 36 acessos foi avaliado em relação à colonização por B. tabaci em testes de livre escolha. Diferenças significativas foram observadas entre acessos para oviposição e o número de ninfas no quarto instar, indicando a presença de fatores de resistência ao inseto. Dez acessos de S. asperolanatum, S. stramonifolium, S. paniculatum e S. syssimbriifolium se mostraram completamente livres de oviposi

Salicylic acid is required for Mi-1-mediated resistance of tomato to whitefly Bemisia tabaci, but not for basal defense to this insect pest.

Science.gov (United States)

Rodríguez-Álvarez, C I; López-Climent, M F; Gómez-Cadenas, A; Kaloshian, I; Nombela, G

2015-10-01

Plant defense to pests or pathogens involves global changes in gene expression mediated by multiple signaling pathways. A role for the salicylic acid (SA) signaling pathway in Mi-1-mediated resistance of tomato (Solanum lycopersicum) to aphids was previously identified and its implication in the resistance to root-knot nematodes is controversial, but the importance of SA in basal and Mi-1-mediated resistance of tomato to whitefly Bemisia tabaci had not been determined. SA levels were measured before and after B. tabaci infestation in susceptible and resistant Mi-1-containing tomatoes, and in plants with the NahG bacterial transgene. Tomato plants of the same genotypes were also screened with B. tabaci (MEAM1 and MED species, before known as B and Q biotypes, respectively). The SA content in all tomato genotypes transiently increased after infestation with B. tabaci albeit at variable levels. Whitefly fecundity or infestation rates on susceptible Moneymaker were not significantly affected by the expression of NahG gene, but the Mi-1-mediated resistance to B. tabaci was lost in VFN NahG plants. Results indicated that whiteflies induce both SA and jasmonic acid accumulation in tomato. However, SA has no role in basal defense of tomato against B. tabaci. In contrast, SA is an important component of the Mi-1-mediated resistance to B. tabaci in tomato.

Pengelolaan Kutu Kebul (Bemisia tabaci Gen. dengan Sistem Barier pada Tanaman Tembakau

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Tri Maruto Aji

2015-07-01

Full Text Available Since 2009, the leaf curl disease was observed on tobacco plants grown under net shadow of PTPN X (Persero and has caused yield losses up to 70%. The disease was likely to be associated with the existence of a high population of the sweet potato whitefly (Bemisia tabaci Gen. and the symptoms resembled that reported for Begomovirus infection on eggplant and tomatoes. This study aimed to know the effectiveness of physical barriers in combination with a biological barrier to avoid B. tabaci in infesting the farm. The research was done by monitoring tobacco diseases to measure the diseases intensity. Research for the management of insect vectorsB. tabaci were done based on two pretexts: (1 physical barrier using the type of net; and (2 combinations of a net with a plant (corn belt. The result showed that an effective control was obtained using a net with higher mesh size rather than using a standard net with low mesh size which was presently used by PTPN X (Persero. Corn barrier did not effective to control B. tabaci except as a wind breaker. INTISARI Peningkatan populasi kutu kebul (B. tabaci Gen. di daerah Klaten, Jawa Tengah pada tahun 2009 ternyata menjadi penyebab mewabahnya penyakit kerupuk pada tanaman Solanaceae di wilayah tersebut. Tanaman tembakau cerutu Vorstenlanden milik PTPN X (Persero yang ditanam di area bawah naungan (TBN yang berada di wilayah tersebut turut terjangkit wabah penyakit kerupuk setelah sebelumnya terindikasi terjadi peningkatan jumlah kutu kebul. Wabah penyakit kerupuk pada tembakau cerutu Vorstenlanden milik PTPN X (Persero telah menurunkan hasil hingga 70%. Gejala penyakit pada tembakau berupa penyakit kerupuk. Penelitian ini bertujuan untuk mengetahui efektivitas penerapan barier fisik sebagai langkah awal untuk mengendalikan populasi kutu kebul pada pertanaman tembakau cerutu milik PTPN X (Persero. Penelitian dimulai dengan memonitoring populasi kutu kebul dan peningkatan intensitas penyakit kerupuk pada tanaman

Toxicological and biochemical basis of synergism between the entomopathogenic fungus Lecanicillium muscarium and the insecticide matrine against Bemisia tabaci (Gennadius)

Science.gov (United States)

Ali, Shaukat; Zhang, Can; Wang, Zeqing; Wang, Xing-Min; Wu, Jian-Hui; Cuthbertson, Andrew G. S.; Shao, Zhenfang; Qiu, Bao-Li

2017-04-01

The sweetpotato whitefly Bemisia tabaci (Gennadius) was challenged with different combinations of matrine (insecticide) and Lecanicillium muscarium (entomopathogenic fungus). Our results revealed a synergistic relationship between matrine and L. muscarium on mortality and enzyme activities of B. tabaci. To illustrate the biochemical mechanisms involved in detoxification and immune responses of B. tabaci against both control agents, activities of different detoxifying and antioxidant enzymes were quantified. After combined application of matrine and L. muscarium, activities of carboxylestrease (CarE), glutathione-s-transferase (GSTs) and chitinase (CHI) decreased during the initial infection period. Acetylcholinestrase (AChE) activities increased during the entire experimental period, whereas those of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) decreased during the later infection period. The increased mortality and suppression of enzymatic response of B. tabaci following matrine and L. muscarium application suggests a strong synergistic effect between both agents. The strong synergistic effect is possibly related to the disturbance of acetylcholine balance and changes in AchE activities of the whitefly as both matrine and L. muscarium target insect acetylcholine (Ach) receptors which in turn effects AchE production. Therefore, our results have revealed the complex biochemical processes involved in the synergistic action of matrine and L. muscarium against B. tabaci.

Bemisia tabaci MED Population Density as Affected by Rootstock-Modified Leaf Anatomy and Amino Acid Profiles in Hydroponically Grown Tomato

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Katja Žanić

2018-02-01

Full Text Available Bemisia tabaci is one of the most devastating pests in tomato greenhouse production. Insecticide resistance management for B. tabaci requires a novel approach that maximizes non-chemical methods for pest control. The aim of this study was to test the effects of rootstocks on B. tabaci populations in hydroponically grown tomato plants. In order to contribute to the better understanding of the mechanisms defining the attractiveness of plant to the aerial pest, the effects of rootstocks on leaf anatomy and the amino acid composition of phloem sap were assessed. A two-factorial experimental design was adopted using cultivars (rootstock cultivars and Clarabella grown as either non-grafted or grafted with cultivar Clarabella as a scion. The rootstock cultivars included Arnold, Buffon, Emperador, and Maxifort. A reduction in B. tabaci density was observed using all rootstock cultivars. The number of adult individuals per leaf was 2.7–5.4 times lower on rootstock cultivars than on Clarabella. The number of large nymphs per square centimeter was at least 24% higher on non–grafted Clarabella compared with all other treatments. The leaf lamina thickness and mesophyll thickness were lower in self-grafted Clarabella than in non-grafted or in one grafted on rootstock cultivars; however, the extent of this reduction depended on the rootstock. The leaves with thinner laminae were generally less attractive to B. tabaci. Eighteen amino acids were detected in the exudates of phloem sap. In all treatments, the most abundant amino acid was γ-aminobutyric acid (GABA, followed by proline, serine, alanine, and histidine. The scion cultivar Clarabella was the most attractive to B. tabaci and had a higher content of leucine than did rootstock cultivars, and a higher content of lysine compared to Buffon and Maxifort. The features modified by rootstock such are changes in leaf anatomy can affect the attractiveness of plants to B. tabaci. Thus, the grafting of tomato

Effects of insecticides used in Bemisia tabaci (Gennadius biotype B control and their selectivity to natural enemies in soybean cropEfeitos dos inseticidas utilizados no controle de Bemisia tabaci (Gennadius biótipo B e sua seletividade aos inimigos naturais na cultura da soja

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Simone Silva Vieira

2012-10-01

Full Text Available In recent crop seasons, the whitefly, Bemisia tabaci biotype B has become a serious pest in soybean crops due to high infestations and its control difficulties. Therefore, it is important to search control alternatives in the integrated pest management approach. Thus, it was evaluated in this study the efficacy of the whitefly control using different insecticides in greenhouse conditions and their selectivity to the parasitoids Encarsia formosa, Trichogramma pretiosum and Telenomus remus. Buprofezin 150 g. a.i.ha-1 + mineral oil 0.2% v/v and pyriproxyfen 100 g. a.i.ha-1 were considered the best options for the whitefly management due to combine good pest control efficacy with higher selectivity to the parasitoids except Encarsia formosa for which no treatment was classified as harmless. Betacyflutrin 9.375 + imidacloprid 75 g. i.a. ha-1 was efficient on controlling whiteflies nymphs but was not harmless to the studied natural enemies. In general, the treatments including pyretroids compounds (betacyflutrin 9.375 + imidacloprid 75 + spiromesifen 60, betacyflutrin 9.375 + imidacloprid 75 and lambda-cyhalothrin 26.5 + thiametoxan 35.25 g. a.i. ha-1 were the most harmful to the evaluated parasitoids and therefore it use should be avoid whenever possible. Nas últimas safras a mosca-branca, Bemisia tabaci biótipo B (Hemiptera: Aleyrodidae tornou-se praga de importância econômica para a cultura da soja devido à ocorrência de altas infestações e à dificuldade de controle desta praga. Sendo assim, é importante buscar alternativas de manejo com base em um programa de manejo integrado de pragas. Assim, avaliaram-se neste trabalho a eficiência de diferentes inseticidas no controle da mosca-branca em casa-de-vegetação e a seletividade destes aos parasitoides Encarsia formosa, Trichogramma pretiosum e Telenomus remus. Buprofezina 150 g i.a. ha-1 + óleo mineral 0,2% v/v e piriproxifem 100 g. i.a. ha-1 foram consideradas as melhores opções para

Colonization of Onions by Endophytic Fungi and Their Impacts on the Biology of Thrips tabaci

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Muvea, Alexander M.; Meyhöfer, Rainer; Subramanian, Sevgan; Poehling, Hans-Michael; Ekesi, Sunday; Maniania, Nguya K.

2014-01-01

Endophytic fungi, which live within host plant tissues without causing any visible symptom of infection, are important mutualists that mediate plant–herbivore interactions. Thrips tabaci (Lindeman) is one of the key pests of onion, Allium cepa L., an economically important agricultural crop cultivated worldwide. However, information on endophyte colonization of onions, and their impacts on the biology of thrips feeding on them, is lacking. We tested the colonization of onion plants by selected fungal endophyte isolates using two inoculation methods. The effects of inoculated endophytes on T. tabaci infesting onion were also examined. Seven fungal endophytes used in our study were able to colonize onion plants either by the seed or seedling inoculation methods. Seed inoculation resulted in 1.47 times higher mean percentage post-inoculation recovery of all the endophytes tested as compared to seedling inoculation. Fewer thrips were observed on plants inoculated with Clonostachys rosea ICIPE 707, Trichoderma asperellum M2RT4, Trichoderma atroviride ICIPE 710, Trichoderma harzianum 709, Hypocrea lixii F3ST1 and Fusarium sp. ICIPE 712 isolates as compared to those inoculated with Fusarium sp. ICIPE 717 and the control treatments. Onion plants colonized by C. rosea ICIPE 707, T. asperellum M2RT4, T. atroviride ICIPE 710 and H. lixii F3ST1 had significantly lower feeding punctures as compared to the other treatments. Among the isolates tested, the lowest numbers of eggs were laid by T. tabaci on H. lixii F3ST1 and C. rosea ICIPE 707 inoculated plants. These results extend the knowledge on colonization of onions by fungal endophytes and their effects on Thrips tabaci. PMID:25254657

Diversity analysis of Bemisia tabaci biotypes: RAPD, PCR-RFLP and sequencing of the ITS1 rDNA region

OpenAIRE

Rabello, Aline R.; Queiroz, Paulo R.; Simões, Kenya C.C.; Hiragi, Cássia O.; Lima, Luzia H.C.; Oliveira, Maria Regina V.; Mehta, Angela

2008-01-01

The Bemisia tabaci complex is formed by approximately 41 biotypes, two of which (B and BR) occur in Brazil. In this work we aimed at obtaining genetic markers to assess the genetic diversity of the different biotypes. In order to do that we analyzed Bemisia tabaci biotypes B, BR, Q and Cassava using molecular techniques including RAPD, PCR-RFLP and sequencing of the ITS1 rDNA region. The analyses revealed a high similarity between the individuals of the B and Q biotypes, which could be distin...

Comparative susceptibility of bemisia tabaci to imidacloprid in field- and laboratory-based bioassays

Science.gov (United States)

Bemisia tabaci biotype B is a resistance-prone pest of protected and open agriculture. Systemic uptake bioassays used in resistance monitoring programs have provided important information on susceptibility to neonicotinoid insecticides, but have remained decoupled from field performance. Simultaneou...

Evidence of diversity and recombination in Arsenophonus symbionts of the Bemisia tabaci species complex

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Mouton Laurence

2012-01-01

Full Text Available Abstract Background Maternally inherited bacterial symbionts infecting arthropods have major implications on host ecology and evolution. Among them, the genus Arsenophonus is particularly characterized by a large host spectrum and a wide range of symbiotic relationships (from mutualism to parasitism, making it a good model to study the evolution of host-symbiont associations. However, few data are available on the diversity and distribution of Arsenophonus within host lineages. Here, we propose a survey on Arsenophonus diversity in whitefly species (Hemiptera, in particular the Bemisia tabaci species complex. This polyphagous insect pest is composed of genetic groups that differ in many ecological aspects. They harbor specific bacterial communities, among them several lineages of Arsenophonus, enabling a study of the evolutionary history of these bacteria at a fine host taxonomic level, in association to host geographical range and ecology. Results Among 152 individuals, our analysis identified 19 allelic profiles and 6 phylogenetic groups, demonstrating this bacterium's high diversity. These groups, based on Arsenophonus phylogeny, correlated with B. tabaci genetic groups with two exceptions reflecting horizontal transfers. None of three genes analyzed provided evidence of intragenic recombination, but intergenic recombination events were detected. A mutation inducing a STOP codon on one gene in a strain infecting one B. tabaci genetic group was also found. Phylogenetic analyses of the three concatenated loci revealed the existence of two clades of Arsenophonus. One, composed of strains found in other Hemiptera, could be the ancestral clade in whiteflies. The other, which regroups strains found in Hymenoptera and Diptera, may have been acquired more recently by whiteflies through lateral transfers. Conclusions This analysis of the genus Arsenophonus revealed a diversity within the B. tabaci species complex which resembles that reported on the

Small RNAs from Bemisia tabaci are transferred to Solanum lycopersicum phloem during feeding

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Paula J.M. Van Kleeff

2016-11-01

Full Text Available The phloem-feeding whitefly Bemisia tabaci is a serious pest to a broad range of host plants, including many economically important crops such as tomato. These insects serve as a vector for various devastating plant viruses. It is known that whiteflies are capable of manipulating host-defense responses, potentially mediated by effector molecules in the whitefly saliva. We hypothesized that, beside putative effector proteins, small RNAs (sRNA are delivered by B. tabaci into the phloem, where they may play a role in manipulating host plant defenses. There is already evidence to suggest that sRNAs can mediate the host-pathogen dialogue. It has been shown that Botrytis cinerea, the causal agent of gray mold disease, takes advantage of the plant sRNA machinery to selectively silence host genes involved in defense signaling.Here we identified sRNAs originating from B. tabaci in the phloem of tomato plants on which they are feeding. sRNAs were isolated and sequenced from tomato phloem of whitefly-infested and control plants as well as from the nymphs themselves, control leaflets and from the infested leaflets. Using stem-loop RT-PCR, three whitefly sRNAs have been verified to be present in whitefly-infested leaflets that were also present in the whitefly-infested phloem sample. Our results show that whitefly sRNAs are indeed present in tomato tissues upon feeding, and they appear to be mobile in the phloem. Their role in the host-insect interaction can now be investigated.

Self-protection of Pseudomonas syringae pv. tabaci from its toxin, tabtoxinine-β-lactam

International Nuclear Information System (INIS)

Knight, T.J.; Durbin, R.D.; Langston-Unkefer, P.J.

1987-01-01

An extracellular toxin, tabtoxinine-β-lactam (TβL), is produced by Pseudomonas syringae pv. tabaci. This toxin irreversibly inhibits its target, glutamine synthetase; yet P. syringae pv. tabaci retains significant amounts of glutamine synthetase activity during toxin production in culture. As part of our investigation of the self-protection of P. syringae pv. tabaci, the authors compared the effects of TβL on Tox + (TβL-producing, insensitive to TβL) and Tox - (TβL nonproducing, sensitive to TΛ) strains. The extent of protection afforded to the Tox - strain when induced to adenylylate glutamine synthetase was tested. It was concluded that an additional protection mechanism was required. A detoxification activity was found in the Tox + strain which opens the ε-lactam ring to TβL to produce the inactive, open-chain form, tabtoxinine. Whole cells of the Tox + strain incubated for 24 h with [ 14 C]TβL (0.276 μmol/3 x 10 10 cells) contained [ 14 C]tabtoxinine (0.056 μmol), and the medium contained TβL (0.226 μmol). Extracts of spheroplasts of the Tox + stain also converted TβL to tabtoxinine, whereas extracts of the Tox - strain did not alter TβL. The conversion was time dependent and stoichiometric and was destroyed by boiling for 30 min or by the addition of 5mM EDTA. Penicillin, a possible substrate and competitive inhibitor of this lactamase activity, inhibited the conversion of TΛ to tabtoxinine. Periplasmic fluid did not catalyze the conversion of TβL

Effect of Iranian Bt cotton on life table of Bemisia tabaci (Hemiptera: Alyrodidae and Cry 1Ab detection in the whitefly honeydew

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Solmaz Azimi

2016-09-01

Full Text Available Transgenic cotton expressing the Cry 1Ab protein of Bacillus thuringiensis developing against Helocoverpa armigera may be affect on secondary pest such as Bemisia tabaci. In this study effects of Bt cotton on demographic parameters of B. tabaci were assessed and the data analyzed using the age specific, two-sex life table parameters. Results showed that getting to the adulthood stage, was faster on non-Bt cotton in comparison with Bt cotton. Also the fecundity was higher on non-Bt cotton than that on Bt cotton. Some of the population parameters (r, R0 and T of B. tabaci were affected by the Bt cotton significantly. The intrinsic rate of increase (r on Bt and non-Bt cotton was 0.07 day-1 and 0.1 day-1 , respectively. The net reproductive rate (R0 was 20.68 and 15.04 offspring/individual on Bt and non-Bt cotton, respectively. Mean generation time (T in non-Bt cotton was 27.22 and 34.62 days in Bt cotton. The results indicated that the life history of B. tabaci in the laboratory condition was influenced by host plant quality and Bt cotton was not a suitable host for B. tabaci. The western immunoblot method showed that the Cry protein detection in honeydew was positive which indicated that the Cry protein was ingested. Results revealed that the transgenic cotton could adversely affect the secondary pest and the natural enemies which feed on such pests as a host or their honeydew as a food source should be considered.

Treehoppers (Homoptera, Membracidae in southeastern Brazil: use of host plants

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Benedito C. Lopes

1995-09-01

Full Text Available A survey on the use of host plants by treehoppers in plants in cerrado (savanna vegetation at Moji-Guaçu (São Paulo, Southeastern Brazil was made. Fifty-two species of treehoppers were recorded in association with 40 host plant species from October 1980 to February 1982. The families Araliaceae, Asteraceae, Leguminosae, Malpighiaceae, Myrtaceae and Nyctaginaceae were the most commonly used for oviposition. Byrsonima intermedia A. Juss. (Malpighiaceae had the highest number of associated treehopper species (10 species. The abundance of treehopper individuals was related to the hot and rainy season (from October to February, while during the cold and dry season (from March to September there was a decrease in the number of these Homoptera. After the occurrence of a frost, few adults and nymphs were observed on the host plants for one to two months.

Incidence of begomoviruses and climatic characterisation of Bemisia tabaci-geminivirus complex in soybean and bean in Argentina Incidencia de begomovirus y caracterización climática del complejo Bemisia tabaci-geminivirus en soja y poroto en Argentina

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V. Alemandri

2012-06-01

Full Text Available Since the 1990s geminiviruses have emerged as devastating pathogens in tropical and subtropical regions as well as in temperate regions. Recent studies accomplished molecular hybridization-based detection of three begomoviruses infecting soybean and bean crops in Argentina, Bean golden mosaic virus (BGMV, Soybean blistering mosaic virus (SbBMV and Tomato yellow spot virus (ToYSV. The aims of the present study were to determine incidence and prevalence of the three known geminiviruses in soybean and bean crops in Argentina following the same procedure and to characterize the sites where Bemisia tabaci-geminivirus complex was found based on climate data. The highest incidence values were observed in Salta province. BGMV exhibited the highest prevalence and incidence values in the bean crop, followed by SbBMV. In the soybean crop, SbBMV showed the highest prevalence and incidence values, followed by ToYSV. One hundred and three soybean and bean plots distributed in Argentina, where the Bemisia tabaci-geminivirus complex was detected, were characterized employing a Geographic Information System (GIS. The complex was found in warm and low rainfall areas; these climatic characteristics are consistent with those identified in a previously described model. A map with the probability of occurrence of B. tabaci-geminivirus, based on the climatic characteristics, was obtained.Desde la década de 1990, los geminivirus han emergido como patógenos devastadores en regiones tropicales, subtropicales y templadas. En estudios recientes, se ha desarrollado un método de detección de tres begomovirus infectando cultivos de soja y poroto en la Argentina, Bean golden mosaic virus (BGMV, Soybean blistering mosaic virus (SbBMV y Tomato yellow spot virus (ToYSV. El objetivo del presente estudio fue determinar la incidencia y prevalencia de estos tres geminivirus y caracterizar los sitios donde se encontró el complejo Bemisia tabaci-geminivirus basándose en datos

EFICIÊNCIA AGRONÔMICA DE INSETICIDAS NO CONTROLE DO Thrips tabaci LIND., 1888 (THYSANOPTERA, THRIPIDAE NA CULTURA DO ALHO AGRONOMIC EFFICIENCY OF INSECTICIDES IN THE CONTROL OF Thrips tabaci LIND., 1888 (THYSANOPTERA, THRIPIDAE ON GARLIC

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Vinícius Caetano Braz

2007-09-01

Full Text Available

O trabalho foi conduzido em Goiânia, Goiás, Brasil, entre maio e agosto de 2000, com o objetivo de determinar a eficiência agronômica dos inseticidas thiacloprid 480 SC, methiocarb 500 SC, imidacloprid 200 SC, betacyflutrin 50 EC, thiametoxan 25 WG e chlorpirifos 450 EC no controle de tripés (Thrips tabaci, na cultura do alho. Os produtos foram aplicados três vezes consecutivas a partir do surgimento do inseto, com intervalos de dez dias. As avaliações foram realizadas aos dois, sete e quinze dias após a terceira pulverização. Concluiu-se que, com exceção do chlorpirifos 450 EC, todos os demais inseticidas foram eficientes no controle do tripes, até quinze dias após a última aplicação. Destacaram-se o methiocarb nas duas dosagens avaliadas, 250 e 375 g.ha^-1 do ingrediente ativo, que apresentaram, em média, 95% e 97,3% de eficiência, respectivamente, e o betacyflutrin 50 EC, com 95,7% de eficiência média.

PALAVRAS-CHAVE: Insecta; tripes; controle químico.

A trial was carried out in Goiânia, Goiás, Brazil, to test the efficiency of insecticides in controlling onion thrips (Thrips tabaci on garlic. The treatments applied were thiacloprid 480 SC; methiocarb 500 SC; imidacloprid 200 SC; betacyfluthrin 50 EC; thiametoxan 25 WG; chlorpiriphos 450 EC, plus an untreated check. The insecticides were sprayed three times at ten-day intervals. Data showed that thiacloprid, methiocarb, imidacloprid, betacyfluthrin and thiametoxan were efficient in controlling the T. tabaci up to 15 days after treatment application. Chlorpiriphos with the tested dosage did not control the T. tabaci efficiently.

KEY-WORDS: Insecta; thrips; chemical control.

EVALUATION DE LA SENSIBILITE A Bemisia tabaci (GEN) DE 13 ...

African Journals Online (AJOL)

AISA

champ, le comportement de 13 variétés de tomate contre la pression de Bemisia tabaci (Gen), une mouche vecteur du virus de la jaunisse en cuillère des ... en saison sèche il y a une vingtaine d'années atteignaient 100 % et les pertes de production ... semaines. Le semis s'est effectué sur une planche de 9 m2 (9 x 1 m2).

Whitefly (Bemisia tabaci genome project: analysis of sequenced clones from egg, instar, and adult (viruliferous and non-viruliferous cDNA libraries

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Czosnek Henryk

2006-04-01

Full Text Available Abstract Background The past three decades have witnessed a dramatic increase in interest in the whitefly Bemisia tabaci, owing to its nature as a taxonomically cryptic species, the damage it causes to a large number of herbaceous plants because of its specialized feeding in the phloem, and to its ability to serve as a vector of plant viruses. Among the most important plant viruses to be transmitted by B. tabaci are those in the genus Begomovirus (family, Geminiviridae. Surprisingly, little is known about the genome of this whitefly. The haploid genome size for male B. tabaci has been estimated to be approximately one billion bp by flow cytometry analysis, about five times the size of the fruitfly Drosophila melanogaster. The genes involved in whitefly development, in host range plasticity, and in begomovirus vector specificity and competency, are unknown. Results To address this general shortage of genomic sequence information, we have constructed three cDNA libraries from non-viruliferous whiteflies (eggs, immature instars, and adults and two from adult insects that fed on tomato plants infected by two geminiviruses: Tomato yellow leaf curl virus (TYLCV and Tomato mottle virus (ToMoV. In total, the sequence of 18,976 clones was determined. After quality control, and removal of 5,542 clones of mitochondrial origin 9,110 sequences remained which included 3,843 singletons and 1,017 contigs. Comparisons with public databases indicated that the libraries contained genes involved in cellular and developmental processes. In addition, approximately 1,000 bases aligned with the genome of the B. tabaci endosymbiotic bacterium Candidatus Portiera aleyrodidarum, originating primarily from the egg and instar libraries. Apart from the mitochondrial sequences, the longest and most abundant sequence encodes vitellogenin, which originated from whitefly adult libraries, indicating that much of the gene expression in this insect is directed toward the production

Implication of the Whitefly Bemisia tabaci Cyclophilin B Protein in the Transmission of Tomato yellow leaf curl virus.

Science.gov (United States)

Kanakala, Surapathrudu; Ghanim, Murad

2016-01-01

Tomato yellow leaf curl virus (TYLCV) is a single-stranded (ssDNA) begomoviruses that causes severe damage to tomato and several other crops worldwide. TYLCV is exclusively transmitted by the sweetpotato whitefly, Bemisia tabaci in a persistent circulative and propagative manner. Previous studies have shown that the transmission, retention, and circulation of TYLCV in its vector involves interaction with insect and endosymbiont proteins, which aid in the transmission of the virus, or have a protective role in response to the presence of the virus in the insect body. However, only a low number of such proteins have been identified. Here, the role of B. tabaci Cyclophilin B (CypB) in the transmission of TYLCV protein was investigated. Cyclophilins are a large family of cellular prolyl isomerases that have many molecular roles including facilitating protein-protein interactions in the cell. One cyclophilin protein has been implicated in aphid-luteovirus interactions. We demonstrate that the expression of CypB from B. tabaci is altered upon TYLCV acquisition and retention. Further experiments used immunocapture-PCR and co-immunolocalization and demonstrated a specific interaction and colocalization between CypB and TYLCV in the the midgut, eggs, and salivary glands. Membrane feeding of anti-CypB antibodies and TYLCV-infected plants showed a decrease in TYLCV transmission, suggesting a critical role that CypB plays in TYLCV transmission. Further experiments, which used membrane feeding with the CypB inhibitor Cyclosporin A showed decrease in CypB-TYLCV colocalization in the midgut and virus transmission. Altogether, our results indicate that CypB plays an important role in TYLCV transmission by B. tabaci .

Implication of the whitefly Bemisia tabaci Cyclophilin B protein in the transmission of Tomato yellow leaf curl virus

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Surapathrudu Kanakala

2016-11-01

Full Text Available Tomato yellow leaf curl virus (TYLCV is a single-stranded (ssDNA begomoviruses that causes severe damage to tomato and several other crops worldwide. TYLCV is exclusively transmitted by the sweetpotato whitefly, Bemisia tabaci in a persistent circulative and propagative manner. Previous studies have shown that the transmission, retention and circulation of TYLCV in its vector involves interaction with insect and endosymbiont proteins, which aid in the transmission of the virus, or have a protective role in response to the presence of the virus in the insect body. However, only a low number of such proteins have been identified. Here, the role of B. tabaci Cyclophilin B (CypB in the transmission of TYLCV protein was investigated. Cyclophilins (Cyps are a large family of cellular prolyl isomerases that have many molecular roles including facilitating protein-protein interactions in the cell. One cyclophilin protein has been implicated in aphid-luteovirus interactions. We demonstrate that the expression of CypB from B. tabaci is altered upon TYLCV acquisition and retention. Further experiments used immunocapture-PCR and co-immunolocalization and demonstrated a specific interaction and colocalization between CypB and TYLCV in the the midgut, eggs and salivary glands. Membrane feeding of anti-CypB antibodies and TYLCV infected plants showed a decrease in TYLCV transmission, suggesting a critical role that CypB plays in TYLCV transmission. Further experiments, which used membrane feeding with the CypB inhibitor Cyclosporin A (CsA showed decrease in CypB-TYLCV colocalization in the midgut and virus transmission. Altogether, our results indicate that CypB plays an important role in TYLCV transmission by B. tabaci.

Transovarial Transmission of Rickettsia spp. and Organ-Specific Infection of the Whitefly Bemisia tabaci

Science.gov (United States)

Brumin, Marina; Levy, Maggie

2012-01-01

The whitefly Bemisia tabaci is a cosmopolitan insect pest that harbors Portiera aleyrodidarum, the primary obligatory symbiotic bacterium, and several facultative secondary symbionts. Secondary symbionts in B. tabaci are generally associated with the bacteriome, ensuring their vertical transmission; however, Rickettsia is an exception and occupies most of the body cavity, except the bacteriome. The mode of Rickettsia transfer between generations and its subcellular localization in insect organs have not been investigated. Using electron and fluorescence microscopy, we show that Rickettsia infects the digestive, salivary, and reproductive organs of the insect; however, it was not observed in the bacteriome. Rickettsia invades the oocytes during early developmental stages and resides in follicular cells and cytoplasm; it is mostly excluded when the egg matures; however, some bacterial cells remain in the egg, ensuring their transfer to subsequent generations. Rickettsia was localized to testicles and the spermatheca, suggesting a horizontal transfer between males and females during mating. The bacterium was further observed at large amounts in midgut cells, concentrating in vacuole-like structures, and was located in the hemolymph, specifically at exceptionally large amounts around bacteriocytes and in fat bodies. Organs further infected by Rickettsia included the primary salivary glands and stylets, sites of possible secretion of the bacterium outside the whitefly body. The close association between Rickettsia and the B. tabaci digestive system might be important for digestive purposes. The vertical transmission of Rickettsia to subsequent generations occurs via the oocyte and not, like other secondary symbionts, the bacteriome. PMID:22660706

Transmission of tomato spotted wilt tospovirus by Thrips tabaci populations originating from leek

NARCIS (Netherlands)

Chatzivassiliou, E.K.; Nagata, T.; Katis, N.I.; Peters, D.

1999-01-01

The transmission of tomato spotted wilt tospovirus (TSWV) by Thrips tabaci collected from leek was studied using the petunia local-lesion leaf-disc assay. After an acquisition-access period of 72 h given to newborn larvae up to 8 h old, the efficiency of transmission by adults was determined in

Detection of Cucurbit chlorotic yellows virus from Bemisia tabaci captured on sticky traps using reverse transcription loop-mediated isothermal amplification (RT-LAMP) and simple template preparation.

Science.gov (United States)

Okuda, Mitsuru; Okuda, Shiori; Iwai, Hisashi

2015-09-01

Cucurbit chlorotic yellows virus (CCYV) of the genus Crinivirus within the family Closteroviridae is an emerging infectious agent of cucurbits leading to severe disease and significant economic losses. Effective detection and identification methods for this virus are urgently required. In this study, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed to detect CCYV from its vector Bemisia tabaci. LAMP primer sets to detect CCYV were evaluated for their sensitivity and specificity, and a primer set designed from the HSP70h gene with corresponding loop primers were selected. The RT-LAMP assay was applied to detect CCYV from viruliferous B. tabaci trapped on sticky traps. A simple extraction procedure using RNAsecure™ was developed for template preparation. CCYV was detected in all of the B. tabaci 0, 1, 7 and 14 days after they were trapped. Although the rise of turbidity was delayed in reactions using RNA from B. tabaci trapped for 7 and 14 days compared with those from 0 and 1 day, the DNA amplification was sufficient to detect CCYV in all of the samples. These findings therefore present a simple template preparation method and an effective RT-LAMP assay, which can be easily and rapidly performed to monitor CCYV-viruliferous B. tabaci in the field. Copyright © 2015 Elsevier B.V. All rights reserved.

A landscape genetic analysis of important agricultural pest species in Tunisia: The whitefly Bemisia tabaci.

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Ahmed Ben Abdelkrim

Full Text Available Combining landscape ecology and genetics provides an excellent framework to appreciate pest population dynamics and dispersal. The genetic architectures of many species are always shaped by environmental constraints. Because little is known about the ecological and genetic traits of Tunisian whitefly populations, the main objective of this work is to highlight patterns of biodiversity, genetic structure and migration routes of this pest. We used nuclear microsatellite loci to analyze B. tabaci populations collected from various agricultural areas across the country and we determine their biotype status. Molecular data were subsequently interpreted in an ecological context supplied from a species distribution model to infer habitat suitability and hereafter the potential connection paths between sampling localities. An analysis of landscape resistance to B. tabaci genetic flow was thus applied to take into account habitat suitability, genetic relatedness and functional connectivity of habitats within a varied landscape matrix. We shed light on the occurrence of three geographically delineated genetic groups with high levels of genetic differentiation within each of them. Potential migration corridors of this pest were then established providing significant advances toward the understanding of genetic features and the dynamic dispersal of this pest. This study supports the hypothesis of a long-distance dispersal of B. tabaci followed by infrequent long-term isolations. The Inference of population sources and colonization routes is critical for the design and implementation of accurate management strategies against this pest.

A landscape genetic analysis of important agricultural pest species in Tunisia: The whitefly Bemisia tabaci.

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Ben Abdelkrim, Ahmed; Hattab, Tarek; Fakhfakh, Hatem; Belkadhi, Mohamed Sadok; Gorsane, Faten

2017-01-01

Combining landscape ecology and genetics provides an excellent framework to appreciate pest population dynamics and dispersal. The genetic architectures of many species are always shaped by environmental constraints. Because little is known about the ecological and genetic traits of Tunisian whitefly populations, the main objective of this work is to highlight patterns of biodiversity, genetic structure and migration routes of this pest. We used nuclear microsatellite loci to analyze B. tabaci populations collected from various agricultural areas across the country and we determine their biotype status. Molecular data were subsequently interpreted in an ecological context supplied from a species distribution model to infer habitat suitability and hereafter the potential connection paths between sampling localities. An analysis of landscape resistance to B. tabaci genetic flow was thus applied to take into account habitat suitability, genetic relatedness and functional connectivity of habitats within a varied landscape matrix. We shed light on the occurrence of three geographically delineated genetic groups with high levels of genetic differentiation within each of them. Potential migration corridors of this pest were then established providing significant advances toward the understanding of genetic features and the dynamic dispersal of this pest. This study supports the hypothesis of a long-distance dispersal of B. tabaci followed by infrequent long-term isolations. The Inference of population sources and colonization routes is critical for the design and implementation of accurate management strategies against this pest.

Density and Seasonal Dynamics of Bemisia tabaci (Gennadius) Mediterranean on Common Crops and Weeds around Cotton Fields in Northern China

DEFF Research Database (Denmark)

Zhang, Xiao-ming; Yang, Nian-wan; Wan, Fang-hao

2014-01-01

theophrasti Medicus), sunflower (Helianthus annuus L.), sweet potato (Ipomoea batatas L.), soybean (Glycine max L.), and maize (Zea mays L.). The whitefly species identity was repeatedly tested and confirmed; seasonal dynamics on the various host plants was standardized by the quartile method. B. tabaci MED......The density seasonal dynamics of Bemisia tabaci MED were evaluated over two-years in a cotton-growing area in Langfang, Hebei Province, northern China on cotton (Gossypium hirsutum L.) and six other, co-occurring common plants: common ragweed (Ambrosia artemisiifolia L.), piemarker (Abutilon...

Global Population Structure of a Worldwide Pest and Virus Vector: Genetic Diversity and Population History of the Bemisia tabaci Sibling Species Group

Science.gov (United States)

2016-01-01

The whitefly Bemisia tabaci sibling species (sibsp.) group comprises morphologically indiscernible lineages of well-known exemplars referred to as biotypes. It is distributed throughout tropical and subtropical latitudes and includes the contemporary invasive haplotypes, termed B and Q. Several well-studied B. tabaci biotypes exhibit ecological and biological diversity, however, most members are poorly studied or completely uncharacterized. Genetic studies have revealed substantial diversity within the group based on a fragment of the mitochondrial cytochrome oxidase I (mtCOI) sequence (haplotypes), with other tested markers being less useful for deep phylogenetic comparisons. The view of global relationships within the B. tabaci sibsp. group is largely derived from this single marker, making assessment of gene flow and genetic structure difficult at the population level. Here, the population structure was explored for B. tabaci in a global context using nuclear data from variable microsatellite markers. Worldwide collections were examined representing most of the available diversity, including known monophagous, polyphagous, invasive, and indigenous haplotypes. Well-characterized biotypes and other related geographic lineages discovered represented highly differentiated genetic clusters with little or no evidence of gene flow. The invasive B and Q biotypes exhibited moderate to high levels of genetic diversity, suggesting that they stemmed from large founding populations that have maintained ancestral variation, despite homogenizing effects, possibly due to human-mediated among-population gene flow. Results of the microsatellite analyses are in general agreement with published mtCOI phylogenies; however, notable conflicts exist between the nuclear and mitochondrial relationships, highlighting the need for a multifaceted approach to delineate the evolutionary history of the group. This study supports the hypothesis that the extant B. tabaci sibsp. group contains

Extended survival of spiders (Aranaeae) feeding on whitefly (Homoptera: Aleyrodidae) honeydew

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Honeydew produced by homopteran insects such as aphids, whiteflies and mealybugs, can be abundant in some crops and may represent an important food resource for spiders and other honeydew feeding natural enemies. Woolly whiteflies are common in south Texas citrus, and spiders consistently make up a...

Identification of an alternative knockdown resistance (kdr)-like mutation, M918L, and a novel mutation, V1010A, in the Thrips tabaci voltage-gated sodium channel gene.

Science.gov (United States)

Wu, Meixiang; Gotoh, Hiroki; Waters, Timothy; Walsh, Douglas B; Lavine, Laura Corley

2014-06-01

Knockdown resistance (kdr) has been identified as a main mechanism against pyrethroid insecticides in many arthropod pests including in the onion thrips, Thrips tabaci. To characterize and identify pyrethroid-resistance in onion thrips in Washington state, we conducted insecticide bioassays and sequenced a region of the voltage gated sodium channel gene from several different T. tabaci populations. Field collected Thrips tabaci were found to have large variations in resistance to the pyrethroid insecticide lambda-cyhalothrin. We identified two single nucleotide substitutions in our analysis of a partial sequence of the T. tabaci voltage-gated sodium channel gene. One mutation resulted in the non-synonymous substitution of methionine with leucine (M918L), which is well known to be responsible for super knockdown resistance in some pest species. Another non-synonymous substitution, a valine (GTT) to alanine (GCT) replacement at amino acid 1010 (V1010A) was identified in our study and was associated with lambda-cyhalothrin resistance. We have characterized a known kdr mutation and identified a novel mutation in the voltage-gated sodium channel gene of Thrips tabaci associated with resistance to lambda-cyhalothrin. This gene region and these mutations are expected to be useful in the development of a diagnostic test to detect kdr resistance in many onion thrips populations. © 2013 Society of Chemical Industry.

Genome sequencing of the sweetpotato whitefly Bemisia tabaci MED/Q.

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Xie, Wen; Chen, Chunhai; Yang, Zezhong; Guo, Litao; Yang, Xin; Wang, Dan; Chen, Ming; Huang, Jinqun; Wen, Yanan; Zeng, Yang; Liu, Yating; Xia, Jixing; Tian, Lixia; Cui, Hongying; Wu, Qingjun; Wang, Shaoli; Xu, Baoyun; Li, Xianchun; Tan, Xinqiu; Ghanim, Murad; Qiu, Baoli; Pan, Huipeng; Chu, Dong; Delatte, Helene; Maruthi, M N; Ge, Feng; Zhou, Xueping; Wang, Xiaowei; Wan, Fanghao; Du, Yuzhou; Luo, Chen; Yan, Fengming; Preisser, Evan L; Jiao, Xiaoguo; Coates, Brad S; Zhao, Jinyang; Gao, Qiang; Xia, Jinquan; Yin, Ye; Liu, Yong; Brown, Judith K; Zhou, Xuguo Joe; Zhang, Youjun

2017-05-01

The sweetpotato whitefly Bemisia tabaci is a highly destructive agricultural and ornamental crop pest. It damages host plants through both phloem feeding and vectoring plant pathogens. Introductions of B. tabaci are difficult to quarantine and eradicate because of its high reproductive rates, broad host plant range, and insecticide resistance. A total of 791 Gb of raw DNA sequence from whole genome shotgun sequencing, and 13 BAC pooling libraries were generated by Illumina sequencing using different combinations of mate-pair and pair-end libraries. Assembly gave a final genome with a scaffold N50 of 437 kb, and a total length of 658 Mb. Annotation of repetitive elements and coding regions resulted in 265.0 Mb TEs (40.3%) and 20 786 protein-coding genes with putative gene family expansions, respectively. Phylogenetic analysis based on orthologs across 14 arthropod taxa suggested that MED/Q is clustered into a hemipteran clade containing A. pisum and is a sister lineage to a clade containing both R. prolixus and N. lugens. Genome completeness, as estimated using the CEGMA and Benchmarking Universal Single-Copy Orthologs pipelines, reached 96% and 79%. These MED/Q genomic resources lay a foundation for future 'pan-genomic' comparisons of invasive vs. noninvasive, invasive vs. invasive, and native vs. exotic Bemisia, which, in return, will open up new avenues of investigation into whitefly biology, evolution, and management. © The Author 2017. Published by Oxford University Press.

Repelência e deterrência na oviposição de Bemisia tabaci biótipo B pelo uso de extratos vegetais em Cucurbita pepo L Repellence and deterrence on oviposition of Bemisia tabaci biotype B by the use of vegetal extracts in Cucurbita pepo L

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J.P.G.F. Silva

2012-01-01

Full Text Available Bemisia tabaci biótipo B é um dos principais insetos-praga na cultura da abobrinha (Cucurbita pepo L.. O manejo dessa mosca-branca tornou-se grande desafio aos agricultores, uma vez que esta apresenta rápida capacidade de desenvolver resistência a diferentes classes de inseticidas. Como alternativa vem sendo investigado o uso de extratos vegetais com atividades inseticida e/ou insetistática, os quais têm revelado resultados promissores no combate a inseto. O presente trabalho teve por objetivo avaliar os possíveis efeitos de sete extratos provenientes de cinco espécies vegetais, Ruta graveolens L. (folhas, Azadirachta indica A. Juss. (folhas + ramos, Trichilia pallida Swartz (ramos, T. pallida (folhas, A. indica (amêndoas, Chenopodium ambrosioides L. (inflorescências + ramos+ folhas e Mentha pulegium L. (folhas, sobre Bemisia tabaci biótipo B em abobrinha, por meio de testes de repelência e deterrência para oviposição. Em teste com chance de escolha, avaliou-se a atratividade e determinou-se o índice de repelência após 6, 24 e 48 horas da aplicação dos extratos. A oviposição foi verificada após a terceira contagem do número de adultos. O extrato à base de folhas de M. pulegium mostrou repelência e deterrência à oviposição de B. tabaci biótipo B, podendo ser recomendado como alternativa para o manejo do inseto.Bemisia tabaci biotype B is one of the main pests in squash (Cucurbita pepo L.. The management of this whitefly has become a major challenge to growers, since they have the ability to quickly develop resistance to different classes of insecticides. Alternatively, the use of plant extracts with insecticide and/or insectistatic activities has been investigated, showing promising results for the whitefly control. The present study evaluated the possible effects of seven extracts from five plant species, Ruta graveolens L. (leaves, Azadirachta indica A. Juss. (leaves + branches, Trichilia pallida Swartz (branches

Implication of the Bacterial Endosymbiont Rickettsia spp. in Interactions of the Whitefly Bemisia tabaci with Tomato yellow leaf curl virus

Science.gov (United States)

Kliot, Adi; Cilia, Michelle; Czosnek, Henryk

2014-01-01

ABSTRACT Numerous animal and plant viruses are transmitted by arthropod vectors in a persistent, circulative manner. Tomato yellow leaf curl virus (TYLCV) is transmitted by the sweet potato whitefly Bemisia tabaci. We report here that infection with Rickettsia spp., a facultative endosymbiont of whiteflies, altered TYLCV-B. tabaci interactions. A B. tabaci strain infected with Rickettsia acquired more TYLCV from infected plants, retained the virus longer, and exhibited nearly double the transmission efficiency compared to an uninfected B. tabaci strain with the same genetic background. Temporal and spatial antagonistic relationships were discovered between Rickettsia and TYLCV within the whitefly. In different time course experiments, the levels of virus and Rickettsia within the insect were inversely correlated. Fluorescence in situ hybridization analysis of Rickettsia-infected midguts provided evidence for niche exclusion between Rickettsia and TYLCV. In particular, high levels of the bacterium in the midgut resulted in higher virus concentrations in the filter chamber, a favored site for virus translocation along the transmission pathway, whereas low levels of Rickettsia in the midgut resulted in an even distribution of the virus. Taken together, these results indicate that Rickettsia, by infecting the midgut, increases TYLCV transmission efficacy, adding further insights into the complex association between persistent plant viruses, their insect vectors, and microorganism tenants that reside within these insects. IMPORTANCE Interest in bacterial endosymbionts in arthropods and many aspects of their host biology in agricultural and human health systems has been increasing. A recent and relevant studied example is the influence of Wolbachia on dengue virus transmission by mosquitoes. In parallel with our recently studied whitefly-Rickettsia-TYLCV system, other studies have shown that dengue virus levels in the mosquito vector are inversely correlated with

The Whitefly Bemisia tabaci Knottin-1 Gene Is Implicated in Regulating the Quantity of Tomato Yellow Leaf Curl Virus Ingested and Transmitted by the Insect

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Aliza Hariton Shalev

2016-07-01

Full Text Available The whitefly Bemisia tabaci is a major pest to agricultural crops. It transmits begomoviruses, such as Tomato yellow leaf curl virus (TYLCV, in a circular, persistent fashion. Transcriptome analyses revealed that B. tabaci knottin genes were responsive to various stresses. Upon ingestion of tomato begomoviruses, two of the four knottin genes were upregulated, knot-1 (with the highest expression and knot-3. In this study, we examined the involvement of B. tabaci knottin genes in relation to TYLCV circulative transmission. Knottins were silenced by feeding whiteflies with knottin dsRNA via detached tomato leaves. Large amounts of knot-1 transcripts were present in the abdomen of whiteflies, an obligatory transit site of begomoviruses in their circulative transmission pathway; knot-1 silencing significantly depleted the abdomen from knot-1 transcripts. Knot-1 silencing led to an increase in the amounts of TYLCV ingested by the insects and transmitted to tomato test plants by several orders of magnitude. This effect was not observed following knot-3 silencing. Hence, knot-1 plays a role in restricting the quantity of virions an insect may acquire and transmit. We suggest that knot-1 protects B. tabaci against deleterious effects caused by TYLCV by limiting the amount of virus associated with the whitefly vector.

Avaliação de extratos vegetais no controle de mosca-branca, Bemisia tabaci biótipo B em abóbora Evaluation of plant extracts in the control of whitefly Bemisia tabaci biotype B in squash

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Bruno Marcus Freire Vieira Lima

2013-09-01

Full Text Available A abóbora (Cucurbita moschata Duch. é uma cultura de importância para a agricultura familiar da região Nordeste do Brasil. No entanto, a ocorrência do prateamento das folhas da aboboreira ocasionado pela mosca-branca, Bemisia tabaci biótipo B limita sua produção, causando prejuízos aos agricultores. O objetivo deste trabalho foi avaliar a eficiência de extratos vegetais sobre o nível populacional de ninfas de mosca-branca em abóbora cv. Jacarezinho. O experimento foi instalado em campo experimental, em blocos casualizados, constituído de seis tratamentos e três repetições. As aplicações dos extratos vegetais foram feitas com intervalo de sete dias, fazendo-se uso de substâncias extraídas das seguintes plantas: canudo (Ipomoea carnea subsp. fistulosa, mamona (Ricinus communis L., tinguí (Mascagnia rigida Griseb, cardo-santo (Argemone mexicana L., e o óleo comercial Natuneem®. Todos os extratos vegetais obtiveram eficiência no controle de ninfas B. tabaci, sendo o R. communis (75,49%, M. rigida (73,99%, I. carnea (72,24%, óleo de nim (70,4% e A. mexicana (69,16%.The squash (Cucurbita moschata Duch. is an important crop for family farmers in the northeast of Brazil. However, the occurrence of leaf silvering caused by the whitefly, Bemisia tabaci biotype B, limits production, causing losses to farmers. The aim of this study was to evaluate the efficiency of plant extracts on the population levels of whitefly nymphs on the squash cv. Jacarezinho. The experiment was conducted at an experimental field, in a randomized block design consisting of six treatments and three replications. Applications of plant extracts were made at an interval of seven days, making use of substances extracted from the following plants: Ipomoea carnea subsp. Fistulosa, castor bean (Ricinus communis L., Tingui (Mascagnia rigida Griseb, cardo-santo (Argemone mexicana L., and the commercial oil product Natuneem ®. All of the plant extracts were

Genetic structure of Bemisia tabaci Med populations from home-range countries, inferred by nuclear and cytoplasmic markers : impact on the distribution of the insecticide resistance genes

OpenAIRE

Gauthier, Nathalie; Clouet, C.; Perrakis, A.; Kapantaidaki, D.; Peterschmitt, M.; Tsagkarakou, A.

2014-01-01

BACKGROUND: Insecticide resistance management in Bemisia tabaci is one of the main issues facing agricultural production today. An extensive survey was undertaken in five Mediterranean countries to examine the resistance status of Med B. tabaci species in its range of geographic origin and the relationship between population genetic structure and the distribution of resistance genes. The investigation combined molecular diagnostic tests, sequence and microsatellite polymorphism studies and mo...

(Brief report Evaluation of Suitable Host Plant, as Banker Plant for Eretmocerus mundus, Whiteflies Parasitoid

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M. J. Ardeh

2016-03-01

Full Text Available Introduction: Whiteflies (Homoptera; Aleyrodidae are the key pests of agricultural crops worldwide. Two species, which seriously damage crops, are the Silver leaf whitefly “Bemisia tabaci (Gennadius” and the Greenhouse whitefly “Trialeorodes vaporariorum (Westwood”. These pests are active on the underside of the leaves where they are relatively protected from insecticide. Moreover, emergence of resistant biotypes of whitelies impose much more costs on its chemical control. Therefore, during falling the past population, several researches have been carried out to find and use efficient biocontrol methods. One of the biocontrol agents to control B. tabaci is “Eretmocerus mundus” (Hy., Aphelinidae. The parasitoid should be introduced to control pest in the greenhouses. One of the methods, which is used in introducing of biological control agents, is ‘Banker Plant System’. In this system, the host plant has a population of reproducing natural enemy used as a reservoir. Therefore, as soon as the pest infection occurs, the parasitoids can find them and control the damage. İn a banker plant system, several aspects should be considered. Some of the behavioral and biological aspects are important. For example characteristics of leaf surface influence on the host finding time of the parasitoid. The biochemical characteristics of the host plants affect the parasitoid fitness. Therefore, we tried to compare these aspects of E. mundus in two host plants (eggplant and cotton from banker plant point of view, to control B. tabaci in the greenhouses. Materials and Methods: The two host plants (eggplant and cotton, were planted in the greenhouse and a culture of B. tabaci was reared on the plants. After two weeks, some of the infested plants were put in separate cages, and the parasitoid, E. mundus, that was collected from the egg plant and cotton fields of the Varamin region were released on the plants. Then, the biological characteristics of

Effect of foliar application of pymetrozine on Bemisia tabaci (MED whitefly) and Amblyseius swirskii, 2016

Science.gov (United States)

Bemisia tabaci is a polyphagous pest known to feed upon over 900 plant taxa, and is an effective vector of more than 100 plant damaging viruses. Among different biotypes of this cryptic species complex, MEAM1 and MED whitefly are the two most destructive members posing threats of several crops of ec...

Inhibition of apoptic cell death induced by Pseudomonas syringae pv. Tabaci and mycotoxin fumonisin B1

NARCIS (Netherlands)

Iakimova, E.T.; Batchvorova, R.; Kapchina, V.; Popov, T.; Atanassov, A.; Woltering, E.J.

2004-01-01

The impact of programmed cell death (PCD) inhibitors on lesion formation and biochemical events in transgenic (ttr line) and non-transgenic (Nevrokop 1164) tobacco infected with Pseudomonas syringae pv. tabaci was tested. Programmed cell death in tomato cell culture was induced by Fumonisin B1 (FUM)

Plant odours with potential for a push-pull strategy to control the onion thrips (Thrips tabaci)

NARCIS (Netherlands)

Tol, van R.W.H.M.; James, D.E.; Kogel, de W.J.; Teulon, D.A.J.

2007-01-01

We compared the efficacy of four plant essential oils to repel onion thrips, Thrips tabaci (Lindeman) (Thysanoptera: Thripidae), in the presence of an attractive odour, ethyl iso-nicotinate in a pasture field. Four horizontal white sticky plates were placed adjacent to (directions: N, S, E, W) a

Temperature stress effects in Bemisia tabaci (Hemiptera: Aleyrodidae) type B whiteflies

Science.gov (United States)

Oxidative stress occurs in response to changes in the redox equilibiurm, which may be caused by increases in reactive oxygen species (ROS), a decrease in antioxidant protection or failure of cells to repair oxidative damage. ROS are either free radicals, reactive molecules containing oxygen atoms or...

Tomato yellow leaf curl virus can be acquired and transmitted by Bemisia tabaci (Gennadius) from tomato fruits

NARCIS (Netherlands)

Delatte, H.; Dalmon, A.; Rist, D.; Soustrade, I.; Wuster, G.; Lett, J.M.; Goldbach, R.W.; Peterschmitt, M.; Reynaud, B.

2003-01-01

The whitefly Bemisia tabaci is an insect pest causing worldwide economic losses, especially as a vector of geminiviruses such as Tomato yellow leaf curl virus (TYLCV). Currently, imported and exported tomato fruit are not monitored for TYLCV infection because they are not considered to represent a

Infection of the whitefly Bemisia tabaci with Rickettsia spp. alters its interactions with Tomato yellow leaf curl virus

Science.gov (United States)

Numerous animal and plant viruses are transmitted by arthropod vectors in a persistent, circulative manner. Tomato yellow leaf curl virus (TYLCV) is transmitted by the sweet potato whitefly Bemisia tabaci. Here we report that infection with Rickettsia spp., a facultative endosymbiont of whiteflies...

Insecticidal and repellent effect of extracts of Pluchea sericea (Nutt. on adults of Bemisia tabaci (Genn.

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Carlos Enrique Ail-Catzim

2015-01-01

Full Text Available Para el control de Bemisia tabaci (Genn. en los cultivos agrícolas se usan repetidas aplicaciones de insecticidas, lo que ha provocado problemas de resistencia y contaminación ambiental. Los insumos provenientes de especies vegetales son una alternativa para reducir esta problemática. Las plantas son una fuente de químicos bioactivos, que pueden tener efecto insecticida, repelente, atrayente, antialimenticio o regulador de crecimiento. El objetivo fue determinar la actividad insecticida y repelente de extractos etanólicos, acetónicos y acuosos, tanto de hojas como de tallos de Pluchea sericea (Nutt. sobre Bemisia tabaci (Genn.. Se estimó la CL50 de cada uno de los extractos, mediante bioensayos con la técnica de película residual, sobre adultos de mosquita blanca. Además, se evaluó el efecto repelente a partir de la CL50 de cada extracto, se estimó el índice de repelencia (IR, si IR = 1 el efecto es neutro, IR 1, el efecto es atrayente. Los extractos de hoja-etanol, hoja-agua y hoja-acetona presentaron valores menores de CL50 700, 1,190 y 1,250 ppm respectivamente, lo que indica alta eficiencia sobre B. tabaci, seguidos del extracto tallo-agua, por último los extractos tallo-etanol y tallo-acetona presentaron menor efectividad. Todos los extractos tuvieron acción repelente, independientemente del disolvente y órgano de la planta a 24 y 48 h. Sin embargo, los extractos a base de agua podrían tener mayor potencial para el control de la mosquita blanca en sistemas de manejo integrado de plagas, debido a que presentaron efecto insecticida y repelente, además el disolvente es inocuo y de bajo costo.

Foraging behavior and prey interactions by a guild of predators on various lifestages of Bemisia tabaci

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James R. Hagler

2004-01-01

Full Text Available The sweetpotato whitefly, Bemisia tabaci (Gennadius is fed on by a wide variety of generalist predators, but there is little information on these predator-prey interactions. A laboratory investigation was conducted to quantify the foraging behavior of the adults of five common whitefly predators presented with a surfeit of whitefly eggs, nymphs, and adults. The beetles, Hippodamia convergens Guérin-Méneville and Collops vittatus (Say fed mostly on whitefly eggs, but readily and rapidly preyed on all of the whitefly lifestages. The true bugs, Geocoris punctipes (Say and Orius tristicolor (Say preyed almost exclusively on adult whiteflies, while Lygus hesperus Knight preyed almost exclusively on nymphs. The true bugs had much longer prey handling times than the beetles and spent much more of their time feeding (35-42% than the beetles (6-7%. These results indicate that generalist predators vary significantly in their interaction with this host, and that foraging behavior should be considered during development of a predator-based biological control program for B. tabaci.

Whitefly species (Hemiptera: Aleyrodidae on wild and cultivated plants in the horticultural region of Rosario, Santa Fe, Argentina Especies de moscas blancas (Hemiptera: Aleyrodidae sobre plantas silvestres y cultivadas en la región hortícola de Rosario, Santa Fe, Argentina

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Gustavo G. Gonsebatt

2012-06-01

Full Text Available Whiteflies of economic importance are polyphagous, being able to develop on a large number of cultivated and spontaneous plants. We recorded the whitefly species on vegetable and flower crops and the wild plants associated, under greenhouse and field conditions, for two years. We observed two species: Trialeurodes vaporariorum (Westwood and the Bemisia tabaci complex (Gennadius. T vaporariorum was recorded on 24 plant species (11 families, 12 and 8 of which are new hosts in Argentina and in the world, respectively. The B. tabaci complex was recorded only on flower production systems, on 19 plant species (11 families, 14 and 7 of which are new hosts in Argentina and in the world, respectively. The crops Glycine max (L. and Chrysanthemum morifolium Ramat., the wild species Amaranthus blitum L., Amaranthus quitensis Kunth, Conyza bonariensis (L., Galinsoga parviflora Cav., Sonchus oleraceus L. and Wedelia glauca (Ortega O. Hoffm. ex Hicken were hosts of both species. The only parasitoid recorded was Eretmocerus californicus near corni Haldeman (Hymenoptera: Aphelinidae from T. vaporariorum. This study, which is the first systematic survey of host plants in the region, intends to provide a better knowledge of the range of whiteflies host plants in Argentina.Las moscas blancas de importancia económica son polífagas y capaces de desarrollarse sobre numerosas plantas cultivadas y espontáneas. Registramos las especies de moscas blancas sobre cultivos hortícolas y de flores, y sobre las plantas silvestres asociadas. Observamos dos especies: Trialeurodes vaporariorum (Westwood y el complejo Bemisia tabaci (Gennadius. T. vaporariorum fue registrada sobre 24 especies de plantas (11 familias, 12 y 8 de las cuales son hospedantes nuevos para Argentina y a nivel mundial, respectivamente. El complejo B. tabaci fue registrado solo en sistemas de producción de flores, sobre 19 especies de plantas (11 familias, 14 y 7 de las cuales son nuevos hospedantes para

Temporal dynamics of iris yellow spot virus and its vector, Thrips tabaci (Thysanoptera: Thripidae), in seeded and transplanted onion fields.

Science.gov (United States)

Hsu, Cynthia L; Hoepting, Christine A; Fuchs, Marc; Shelton, Anthony M; Nault, Brian A

2010-04-01

Onion thrips, Thrips tabaci (Lindeman) (Thysanoptera: Thripidae), can reduce onion bulb yield and transmit iris yellow spot virus (IYSV) (Bunyaviridae: Tospovirus), which can cause additional yield losses. In New York, onions are planted using seeds and imported transplants. IYSV is not seed transmitted, but infected transplants have been found in other U.S. states. Transplants are also larger than seeded onions early in the season, and thrips, some of which may be viruliferous, may preferentially colonize larger plants. Limited information is available on the temporal dynamics of IYSV and its vector in onion fields. In 2007 and 2008, T. tabaci and IYSV levels were monitored in six seeded and six transplanted fields. We found significantly more thrips in transplanted fields early in the season, but by the end of the season seeded fields had higher levels of IYSV. The percentage of sample sites with IYSV-infected plants remained low (fields. The densities of adult and larval thrips in August and September were better predictors of final IYSV levels than early season thrips densities. For 2007 and 2008, the time onions were harvested may have been more important in determining IYSV levels than whether the onions were seeded or transplanted. Viruliferous thrips emigrating from harvested onion fields into nonharvested ones may be increasing the primary spread of IYSV in late-harvested onions. Managing T. tabaci populations before harvest, and manipulating the spatial arrangement of fields based on harvest date could mitigate the spread of IYSV.

Six New Record Species of Whiteflies (Hemiptera: Aleyrodidae) Infesting Morus alba in China

Science.gov (United States)

Wang, Ji-Rui; Song, Zao-Qin; Du, Yu-Zhou

2014-01-01

Abstract To determine the species of whiteflies occurring on mulberry, Morus alba L. (Rosales: Moraceae) in China, we collected samples in more than 87 sites in 16 provinces of China from 2008 to 2011. In total, 10 species, representing seven genera of the subfamily Aleyrodinae, were identified. Of these, six species are newly recorded on mulberry in China, namely, Aleuroclava ficicola Takahashi, Aleuroclava gordoniae (Takahashi), Aleurotrachelus camelliae (Kuwana), Bemisia afer (Priesner & Hosny), Bemisia tabaci Gennadius, and Pealius machili Takahashi. Information on the taxonomy, distribution, and host plants of the whitefly species found on mulberry in China, along with a brief description and illustrations of each species are provided. PMID:25368095

Age-specific interaction between the parasitoid, Encarsia formosa and its host, the silverleaf whitefly, Bemisia tabaci (Strain B

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Jing S. Hu

2003-08-01

Full Text Available The effect of hostage, the instar of Bemisia tabaci (Gennadius parasitized, on the growth and development of Encarsia formosa (Gahan was studied. E. formosa was able to parasitize and complete its life cycle no matter which instar of B. tabaci (Strain B, [also identified as B. argentifolii (Bellows and Perring], was provided for oviposition, but parasitoid development was significantly slower when 1st or 2nd instar B. tabaci rather than 3rd or 4th instars were parasitized. Host age influenced the day on which E. formosa nymphs hatching from eggs was first observed. Mean embryonic development was significantly longer when 1st (5.4 days rather than 2nd, 3rd or 4th instars (4.1, 3.4 and 3.5 days, respectively were parasitized. The duration of the 1st instar parasitoid and the pupa, but not the 2nd or 3rd instar parasitoid, were also significantly greater when 1st instars were parasitized than when older host instars were parasitized. Interestingly, no matter which instar was parasitized, the parasitoid did not molt to the 3rd instar until the 4th instar host had reached a depth of about 0.23 mm (Stage 4-5 and had initiated the nymphal-adult molt and adult development. Histological studies revealed that whitefly eye and wing structures had either disintegrated or were adult in nature whenever a 3rd instar parasitoid was present. It appears, then, that the molt of the parasitoid to its last instar is associated with the host whitefly's nymphal-adult molt. However, the initiation of the host's final molt, while a prerequisite for the parasitoid's 2nd-3rd instar molt, did not necessarily trigger this molt. In contrast to its significant effect on various aspects of parasitoid development, host instar did not significantly influence the mean size of the parasitoid larva, pupa, or adult. Larval and pupal length and adult head width were similar for all parasitoids, regardless of which host instar was parasitized as was adult longevity. Adult parasitoid

Efficacy of plant derived oils and extracts against white-fly, bemisia tabaci (gennadius) on sesame crop

International Nuclear Information System (INIS)

Iram, A.; Irfan, M.; Aslam, S.

2014-01-01

Whitefly, Bemisia tabaci (Genn.) is a polyphagous pest and is reported on more than 600 host plants worldwide. Different methods are being used for its control. The present experiment was conducted to determine the effect of some plant extracts of mint (Mentha spp.) and gera-nium (Pelargonium graveolens) and soybean oil (Glycine max), mustard oil (Brassica spp.) and taramera oil (Eruca sativa) against whitefly, Bemisia tabaci on sesame crop. The data were recorded 24h before and 24h, 48h, 72h and 168h after application of each spray material. The results showed that whitefly population was significantly suppressed by both the botanical oils and extracts as compared to the control treatment but in general botanical oils showed significant results as compared to plant extracts. Soybean oil was quite effective in reducing whitefly population per leaf, while after second spray soybean oil and extract of Mentha spp. was more effective in the reducing whitefly population per leaf. The results indicated that plant derived oils and extracts have the potential to be used in plant protection strategies but still more research has to be incorporated in the pest management programmes. (author)

Controle da pérola-da-terra, Eurhizococcus brasiliensis (Hempel) (Homoptera:Margarodidae), através da insetigação

OpenAIRE

Hickel, Eduardo R.; Peruzzo, Edegar L.; Schuck, Enio

2001-01-01

A pérola-da-terra, Eurhizococcus brasiliensis (Hempel) (Homoptera: Margarodidae), é a principal praga da videira no Sul do Brasil. As estratégias normais de controle desta praga não afetam a população do inseto porque os indivíduos estão no subsolo e desenvolvem um corpo globoso resistente a intempéries. Assim sendo, um ensaio foi conduzido em laboratório para verificar a possibilidade de aplicar a insetigação no controle da pérola-da-terra. Tubos de 50 mm de altura de cano PVC (150 mm fi) fo...

Responses of Nasonovia ribisnigri (Homoptera: Aphididae) to susceptible and resistant lettuce.

Science.gov (United States)

Liu, Yong-Biao; McCreight, James D

2006-06-01

Nymphs and alates of aphid Nasonovia ribisnigri (Mosley) (Homoptera: Aphididae) were tested on 10 lettuce cultivars with N. ribisnigri resistance gene Nr and 18 cultivars without the resistance gene in various bioassays. Bioassays used whole plants, leaf discs, or leaf cages to determine susceptibility of commercial lettuce cultivars to N. ribisnigri infestation and to evaluate screening methods for breeding lettuce resistance to N. ribisnigri. Resistant and susceptible plants were separated in 3 d when using whole plant bioassays. Long-term (> or =7 d) no-choice tests using leaf cages or whole plants resulted in no survival of N. ribisnigri on resistant plants, indicating great promise of the Nr gene for management of N. ribisnigri. Effective screening was achieved in both no-choice tests where resistant or susceptible intact plants were tested separately in groups or individually and in choice tests where susceptible and resistant plants were intermixed. Leaf discs bioassays were not suitable for resistance screening. All lettuce cultivars without the resistance gene were suitable hosts for N. ribisnigri, indicating the great importance of this pest to lettuce production and the urgency in developing resistant lettuce cultivars to manage N. ribisnigri.

Biological Invasions of Geminiviruses: Case Study of TYLCV and Bemisia tabaci in Reunion Island

Science.gov (United States)

Péréfarres, Frédéric; Thierry, Magali; Becker, Nathalie; Lefeuvre, Pierre; Reynaud, Bernard; Delatte, Hélène; Lett, Jean-Michel

2012-01-01

In the last 20 years, molecular ecology approaches have proven to be extremely useful to identify and assess factors associated with viral emerging diseases, particularly in economically and socially important tropical crops such as maize (maize streak disease) and cassava (cassava mosaic disease). Molecular ecology approaches were applied in Reunion Island to analyze the epidemic of tomato yellow leaf curl disease, which has been affecting the island since the end of the 1990s. Before the invasive biotype B (currently known as Middle East-Asia Minor 1 cryptic species) of Bemisia tabaci spread across the world, Reunion Island (South West Indian Ocean) only hosted an indigenous biotype of B. tabaci, Ms (currently known as Indian Ocean cryptic species). Wild hybrids between invasive and indigenous species were subsequently characterized over multiple generations. Endosymbiont analysis of the hybrid population indicated that matings were non-random. Similarly, while no indigenous begomoviruses have ever been reported on Reunion Island, the two main strains of one of the most damaging and emerging plant viruses in the world, the Mild and Israel strains of the Tomato yellow leaf curl virus (TYLCV-Mld and TYLCV-IL), were introduced in 1997 and 2004 respectively. While these introductions extensively modified the agricultural landscape of Reunion Island, they also provided an invaluable opportunity to study the ecological and genetic mechanisms involved in biological invasion and competition. PMID:23235470

The role of weeds in the spread of Tomato spotted wilt virus by thrips tabaci (Thysanoptera: Thripidae) in tobacco crops

NARCIS (Netherlands)

Chatzivassiliou, E.K.; Peters, D.; Katis, N.I.

2007-01-01

Oviposition of Thrips tabaci, larval development and their potential to acquire Tomato spotted wilt virus (TSWV) from infected Amaranthus retroflexus, Datura stramonium, Lactuca serriola, Solanum nigrum and Sonchus oleraceus plants and the ability of the adults to transmit this virus to these weeds

Whitefly species (Hemiptera: Aleyrodidae on wild and cultivated plants in the horticultural region of Rosario, Santa Fe, Argentina

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Gustavo G. GONSEBATT

2012-01-01

Full Text Available Las moscas blancas de importancia económica son polífagas y capaces de desarrollarse sobre numerosas plantas cultivadas y espontáneas. Registramos las especies de moscas blancas sobre cultivos hortícolas y de flores, y sobre las plantas silvestres asociadas. Observamos dos especies: Trialeurodes vaporariorum (Westwood y el complejo Bemisia tabaci (Gennadius. T. vaporariorum fue registrada sobre 24 especies de plantas (11 familias, 12 y 8 de las cuales son hospedantes nuevos para Argentina y a nivel mundial, respectivamente. El complejo B. tabaci fue registrado solo en sistemas de producción de flores, sobre 19 especies de plantas (11 familias, 14 y 7 de las cuales son nuevos hospedantes para Argentina y a nivel mundial, respectivamente. Los cultivos Glycine max (L. y Chrysanthemum morifolium Ramat., las especies silvestres Amaranthus blitum L., Amaranthus quitensis Kunth, Conyza bonariensis (L., Galinsoga parviflora Cav., Sonchus oleraceus L. y Wedelia glauca (Ortega O. Hoffm. ex Hicken fueron hospedantes de ambas especies. El único parasitoide registrado fue Eretmocerus californicus cercano a corni Haldeman (Hymenoptera: Aphelinidae sobre T. vaporariorum. Este estudio que constituye el primer relevamiento sistemático de plantas hospedantes en la región, aporta un mayor conocimiento sobre el rango de plantas hospedantes de las moscas blancas en Argentina.

Genetic variability of the whitefly Bemisia tabaci and its secondary endosymbionts in the Arabian Peninsula

KAUST Repository

Ragab, Alaa I.

2013-05-01

The whitefly Bemisia tabaci species complex has been well documented as one of the most economically important emergent plant virus vectors, through serious feeding damage to its broad range of plant hosts and transmission of plant viruses to important agricultural crops. It has been shown to have associations with endosymbionts which have significant effects on the insect fitness. The purpose of this study was to provide information for the biotype and secondary endosymbiont distribution for B. tabaci populations in the relatively unstudied Arabian peninsula. The geographical localization and variation in endosymbiont populations across the region were identified using a sequence-driven analysis of the population genetics of the secondary endosymbiont. Live field specimens were collected from 22 different locations in the region and preserved in 70% ethanol for genetic studies. Previously established procedures were used to extract and purify total insect DNA from 24-30 individual whiteflies for each location (Frohlich et al., 1999; Chiel et al., 2007). Specimens were subjected to PCR amplification using the respective 16S rDNAprimers for the Rickettsia, Hamiltonella, and Wolbachia to amplify endosymbiont DNA. PCR was run with primers for the highly conserved whitefly mitochondrial cytochrome oxidase subunit I (COI) gene for biotyping. Samples were sequenced using the Sanger method and the data analyzed to correlate the presence, prevalence and geographical distribution of endosymbionts in B. tabaci. Phylogenies 5 were constructed to track evolutionary differences amongst the endosymbionts and insects and how they have influenced the evolution of the regional populations. Samples were characterized by differences in the genomes and endosymbionts of common whitefly ‘biotypes’ that have different host plant preferences, vector capacities and insecticide resistance characteristics. It was found that the B biotype is the predominant haplotype, with no evidence of

The immune strategy and stress response of the Mediterranean species of the Bemisia tabaci complex to an orally delivered bacterial pathogen.

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Chang-Rong Zhang

Full Text Available BACKGROUND: The whitefly, Bemisia tabaci, a notorious agricultural pest, has complex relationships with diverse microbes. The interactions of the whitefly with entomopathogens as well as its endosymbionts have received great attention, because of their potential importance in developing novel whitefly control technologies. To this end, a comprehensive understanding on the whitefly defense system is needed to further decipher those interactions. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a comprehensive investigation of the whitefly's defense responses to infection, via oral ingestion, of the pathogen, Pseudomonas aeruginosa, using RNA-seq technology. Compared to uninfected whiteflies, 6 and 24 hours post-infected whiteflies showed 1,348 and 1,888 differentially expressed genes, respectively. Functional analysis of the differentially expressed genes revealed that the mitogen associated protein kinase (MAPK pathway was activated after P. aeruginosa infection. Three knottin-like antimicrobial peptide genes and several components of the humoral and cellular immune responses were also activated, indicating that key immune elements recognized in other insect species are also important for the response of B. tabaci to pathogens. Our data also suggest that intestinal stem cell mediated epithelium renewal might be an important component of the whitefly's defense against oral bacterial infection. In addition, we show stress responses to be an essential component of the defense system. CONCLUSIONS/SIGNIFICANCE: We identified for the first time the key immune-response elements utilized by B. tabaci against bacterial infection. This study provides a framework for future research into the complex interactions between whiteflies and microbes.

Whitefly population dynamics in okra plantations Dinâmica populacional de mosca-branca em quiabo

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Germano Leão Demolin Leite

2005-01-01

Full Text Available The control of whitefly Bemisia tabaci (Gennadius biotype B (Hemiptera: Aleyrodidae on okra (Abelmoschus esculentus L. consists primarily in the use of insecticides, due to the lack of information on other mortality factors. The objective of this study was to evaluate the spatial and temporal population dynamics of the whitefly B. tabaci biotype B on two successive A. esculentus var. "Santa Cruz" plantations. Leaf chemical composition, leaf nitrogen and potassium contents, trichome density, canopy height, plant age, predators, parasitoids, total rainfall and median temperature were evaluated and their relationships with whitefly on okra were determined. Monthly number estimates of whitefly adults, nymphs (visual inspection and eggs (magnifying lens occurred on bottom, middle and apical parts of 30 plants/plantation (one leaf/plant. Plants senescence and natural enemies, mainly Encarsia sp., Chrysoperla spp. and Coccinellidae, were some of the factors that most contributed to whitefly reduction. The second okra plantation, 50 m apart from the first, was strongly attacked by whitefly, probably because of the insect migration from the first to the second plantation. No significant effects of the plant canopy on whitefly eggs and adults distribution were found. A higher number of whitefly nymphs was found on the medium part than on the bottom part.O controle da mosca-branca Bemisia tabaci (Gennadius biótipo B (Hemiptera: Aleyrodidae em quiabeiro (Abelmoschus esculentus L. consiste principalmente no uso de inseticidas, em virtude da falta de informação sobre outros fatores de mortalidade. O objetivo deste trabalho foi compreender a dinâmica populacional, espacial e temporal da mosca-branca em dois cultivos sucessivos de quiabeiro "Santa Cruz". Avaliaram-se a composição química foliar, os níveis foliares de nitrogênio e de potássio, a densidade de tricomas, a altura de dossel, a idade de planta, predadores, parasitóides, pluviosidade total

Genome-wide analyses of the Bemisia tabaci species complex reveal contrasting patterns of admixture and complex demographic histories.

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S Elfekih

Full Text Available Once considered a single species, the whitefly, Bemisia tabaci, is a complex of numerous morphologically indistinguishable species. Within the last three decades, two of its members (MED and MEAM1 have become some of the world's most damaging agricultural pests invading countries across Europe, Africa, Asia and the Americas and affecting a vast range of agriculturally important food and fiber crops through both feeding-related damage and the transmission of numerous plant viruses. For some time now, researchers have relied on a single mitochondrial gene and/or a handful of nuclear markers to study this species complex. Here, we move beyond this by using 38,041 genome-wide Single Nucleotide Polymorphisms, and show that the two invasive members of the complex are closely related species with signatures of introgression with a third species (IO. Gene flow patterns were traced between contemporary invasive populations within MED and MEAM1 species and these were best explained by recent international trade. These findings have profound implications for delineating the B. tabaci species status and will impact quarantine measures and future management strategies of this global pest.

Studies on the Susceptibility of Different Developmental Stages of [Bemisia tabaci (Gennadius] to Pyriproxyfen and Citowett Oil

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sedighe ashtari

2018-02-01

Full Text Available Introduction: Bemisia tabaci is highly polyphagous herbivore. This is one of the most important cotton pests throughout the world. Bemisia tabaci causes noticeable damage to quality and quantity of cotton yield. Due to its special habitat, the present efforts to control of the pest have focused on the application of chemical insecticides. It is well established that the overuse and misuse of these compounds can lead to environemntal disasters and development of resistance. Therefore, undertakening research for a safe and environment- compatible method of control has been warranted. In our research, the degree of sensitivity of different life stages of B. tabaci to a juvenile hormone analogue compound and citowett oil was evaluated. Materials and Methods: For this purpose, specimens were collected from contaminated tomato and tobacco flowerpots in the greenhouse of the Faculty of Agriculture at Urmia University. After immersion of leaves in the pesticide solutions, the sensitivity of different life stages was evaluated. The purpose of this test is to determine the range of concentrations of insecticides which would cause 25-75 percent death rate. The main concentrations were calculated by the concentration of preliminary experiments.The control mortality was corrected using Abbott's formula. Results and Discussion: At the termination of experiments the following results were obtained: in all of the treatments, nymph, pupa and egg stages were the most sensitive ones to this compound, respectively, because the juvenile hormone analogue affected the egg and the immature stages but did not affect the adult insects. In the citowett oil treatment nymph, pupa and egg were the most sensitive stages and the adult insect was the most resistant one. The LC50 value of pyriproxyfen after 24 hours for the adult, egg, nymph along with pupa stages (immature stages were 973.1530, 45.045 and 11.4468 ppm, respectively. The LC50 value of citowett oil after 24 hour

Genetic structure of Bemisia tabaci Med populations from home-range countries, inferred by nuclear and cytoplasmic markers: impact on the distribution of the insecticide resistance genes.

Science.gov (United States)

Gauthier, Nathalie; Clouet, Cécile; Perrakis, Andreas; Kapantaidaki, Despoina; Peterschmitt, Michel; Tsagkarakou, Anastasia

2014-10-01

Insecticide resistance management in Bemisia tabaci is one of the main issues facing agricultural production today. An extensive survey was undertaken in five Mediterranean countries to examine the resistance status of Med B. tabaci species in its range of geographic origin and the relationship between population genetic structure and the distribution of resistance genes. The investigation combined molecular diagnostic tests, sequence and microsatellite polymorphism studies and monitoring of endosymbionts. High frequencies of pyrethroid (L925I and T929V, VGSC gene) and organophosphate (F331W, ace1 gene) resistance mutations were found in France, Spain and Greece, but not in Morocco or Tunisia. Sequence analyses of the COI gene delineated two closely related mitochondrial groups (Q1 and Q2), which were found either sympatrically (Spain) or separately (France). Only Q1 was observed in Greece, Morocco and Tunisia. Bayesian analyses based on microsatellite loci revealed three geographically delineated genetic groups (France, Spain, Morocco/Greece/Tunisia) and high levels of genetic differentiation even between neighbouring samples. Evidence was also found for hybridisation and asymmetrical gene flow between Q1 and Q2. Med B. tabaci is more diverse and structured than reported so far. On a large geographic scale, resistance is affected by population genetic structure, whereas on a local scale, agricultural practices appear to play a major role. © 2014 Society of Chemical Industry.

Entomopathogenic fungi from 'El Eden' Ecological Reserve, Quintana Roo, Mexico.

Science.gov (United States)

Torres-Barragán; Anaya, Ana Luisa; Alatorre, Raquel; Toriello, Conchita

2004-07-01

Entomopathogenic fungi were isolated and identified from insects collected from the tropical forest and an agricultural area at El Eden Ecological Reserve, Quintana Roo, Mexico. These fungi were studied to determine their potential as biological control agents of greenhouse Trialeurodes vaporariorum (Homoptera: Aleyrodidae), and to contribute to the knowledge of biodiversity of this area. No pest insects were observed in the tropical forest. In contrast, all insects collected in the agricultural area were considered important pests by the local farmers, with the whitefly, as the most relevant, plentiful in Cucurbitaceae plants. From approximately 3400 collected insects in three different surveys, different anamorphic Ascomycetes were recovered. One isolate of Aspergillus sp., two of Penicillium sp., three of Paecilomyces marquandii, and three of Verticillium sp. out of 308 insects (2.9%) from three insect orders, Hymenoptera, Diptera and Isoptera in the tropical forest. In contrast, a higher number of fungal isolates were recovered from the agricultural area: three isolates from Aspergillus parasiticus, 100 of Fusarium moniliforme, one of Aschersonia sp., and 246 of Fusarium oxysporum out of 3100 insects (11.3%) from three insect orders, Homoptera, Coleoptera and Lepidoptera. The results of this study show Fusarium moniliforme and F oxysporum as highly virulent to infected insects in the agricultural area, with 100 and 246 isolates respectively, out of 350 infected insects of 3100 studied specimens. Laboratory whitefly nymph bioassays with isolates Ed29a of F. moniliforme, Ed322 of F. oxysporum, and Ed22 of P marquandii showed 96 to 97.5% insect mortality with no significant differences (P < 0.05) among them. F. oxysporum Ed322 produced no mortality when inoculated on tomato, bean, squash and maize seedlings (with and without injuries) compared to the 100% mortality caused by phytopathogenic strains, F. oxysporum f. sp. lycopersici and F. oxysporum f. sp. radicis

Biological control of fruit flies (Diptera: Tephritidae) through parasitoid augmentative releases: Current status

International Nuclear Information System (INIS)

Montoya, Pablo; Liedo, Pablo

2000-01-01

Fruit flies are among the main pests affecting the world fruit industry (Aluja 1993). Bait sprays have traditionally been used successfully to control them; however, the side effects on the environment and health hazards commonly associated with pesticides, have resulted in strong public opposition to the use of bait sprays. This is particularly so when sprays are applied in urban areas or in coffee plantations where, although Medflies are present, they do not pose a danger to crops. Alternative methods that are effective and environmental friendly to suppress fruit fly populations are highly desirable. Biological control, the use of natural enemies to suppress pest populations, represents such an alternative. Some of the most successful cases of biological control are the control of Iceria purchasi Maskell (Homoptera: Margarodidae) by Rodolia cardinalis Mulsant (Coleoptera: Coccinellidae) in California (De Bach 1968, van den Bosch et al. 1982), and the control of Aleurocanthus woglumi Ashby (Homoptera: Aleyrodidae) mainly by Encarsia (=Prospaltella) opulenta Silv. (Hymenoptera: Aphelinidae) in Mexico (Jimenez 1961, 1971), both using the classical approach. However, this approach has been limited to certain conditions of environmental stability and biodiversity which are only found in a few ecosystems. Other factors, such as types of pests, the economic threshold and product quality requirements represent additional limitations. The best option in many cases could be augmentative biological control, which could overcome some of the deficiencies of the classical approach (Sivinski 1996). According to Knipling (1992) and Barclay (1987), augmentative biological control can be considered as a formal alternative for suppressing pest populations and even for use in eradication programmes, after integration with the sterile insect technique (SIT). In this approach, mass production of natural enemies is required and this production has to be cost effective

Radiation sterilization of the greenhouse white fly (Trialeurodes vaporariorum Westw., Homoptera, Aleyrodidae). Part 2

International Nuclear Information System (INIS)

Genchev, N.

1987-01-01

Results are reported of studies of the sterilizing effect on puparia and imagoes of the greenhouse white fly (T. vaporariorum). The irradiation was made by gamma rays at the rate of 12+-5% rad/s. The parameters of radiation-induced sterility were sex determined. The sterilizing effect was expressed in emergence of dominant lethal mutations in spermatozoa accompanied by partial sperm inactivation and of partial aspermia. The absolute sterilizing doses for the two ontogenetic stage are 6 and 7 krad respectively. Radiation induced sterilization of the male parent resulted in forced arrhenotoky in F 1 and was regarded as a transformation of parthogenesis factor necessary for the normal propagation in the insect process into one that is lethal to the population factor. Radiation induced female sterility in females was expressed in the emergence of dominant lethals in oocytes. The absolute sterilizing doses for the puparium and the imago were 5 and 6 krad, respectively. Doses ≥4 krad caused partial infertility

Quantifying conservation biological control for management of Bemisia tabaci (Hemiptera: Aleyrodidae) in cotton

Science.gov (United States)

Conservation biological control can be an effective tactic for minimizing insect-induced damage to agricultural production. The most effective manner of applying CBC is through an Integrated Pest Management (IPM) strategy, combining many tactics including cultural controls, pest sampling, the use of...

No transmission of Potato spindle tuber viroid shown in experiments with thrips (Frankliniella occidentalis, Thrips tabaci), honey bees (Apis mellifera) and bumblebees (Bombus terrestris)

DEFF Research Database (Denmark)

Nielsen, Steen Lykke; Enkegaard, Annie; Nicolaisen, Mogens

2012-01-01

and Thrips tabaci by leaf sucking. The F. occidentalis experiments also included feeding on pollen prior to feeding on PSTVd-infected leaf. No thrips-mediated transmission of PSTVd was recorded. The possibility of PSTVd transmission by Apis mellifera and Bombus terrestris during their feeding...

Taxonomic notes on some Polyglyptini: descriptions of new genus and new species (Homoptera, Membracidae, Smiliinae

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Albino M. Sakakibara

1996-01-01

Full Text Available Taxonomic notes on some Polyglyptini; descriptions of new genus and new species (Homoptera, Membracidae, Smiliinae. The genera Hemiptycha Germar, Metheisa Fowler, Maturnaria Metcalf, Aphetea Fowler, Dioclophara Kirkaldy, and Phormophora Stål, are redescribed; Creonus, gen.n. (type species: Maturna lloydi Funkhouser, 1914, and Aphetea robustula, sp.n. (from Bolivia, are described. Some nomenclatural changes are introduced, as follow: - Hemiptycha Germar, 1833 = Polyrhyssa Stål, 1869, syn.n.: - Hemiptycha cultrata (Coquebert, 1801, comb.n., = Polyglyptodes flavocostatus Haviland, 1925, syn.n., = Polyrhyssa cultrata maculata Fonseca, 1942, syn.n. - Hemiptycha obtecta (Fabricius, 1803 = Hille herbicola Haviland, 1925, syn.n. - Maturnaria ephippigera (Fairmaire, 1846 = Publilia tumulata Buckton, 1903, syn.n., = Metheisa fowleri Funkhouser, 1927, syn.n. - Creonus lloydi (Funkhouser, 1914, comb.n. - Aphetea parvula (Fabricius, 1803, comb.n., = Aphetea affinis Haviland, 1925, syn.n. - Dioclophara Kirkaldy, 1904 = lncolea Goding, 1926, syn.n. - Dioclophara viridula (Fairmaire, 1846 = Maturna multilineata Fonseca, 1942, syn.n. - Dioclophara variegata (Goding, 1926, comb.n. = lncolea viridis Goding, 1926, syn.n. - Phormophora maura (Fabricius, 1803 = Darnis dorsata Fabricius, 1803, syn.n.

CASOS SELECTOS DE RESISTENCIA A INSECTICIDAS EN MOSCAS BLANCAS (Hemiptera: Aleyrodidae EN EL MUNDO

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Macías-flores A

2013-01-01

Full Text Available Las moscas blancas (Hemíptera: Aleyrodidae son un problema a escala global. En México, llamó la atención como plaga agrícola en la década de los años 80´s y 90´s del siglo pasado por las pérdidas económicas que ocasionaron en los cultivos agrícolas, debido a los daños directos por la succión de savia y a los daños indirectos por la transmisión de enfermedades de origen viral. El hombre en su intento fallido por erradicarlas ha hecho uso desmedido de insecticidas químicos, quizás por su accesibilidad por costo bajo o por efectos de control inmediatos, por lo cual ha causado daño al medio ambiente y a la salud humana, con la consecuencia de desarrollo de resistencia. En un intento por disminuir los efectos de tales sustancias, muchas investigaciones alrededor del mundo se han conducido para encontrar productos insecticidas más efectivos con el menor impacto ambiental y a la salud humana, y que contribuyan a incrementar las herramientas de control disponibles en los sistemas de producción agrícola.

Nitrogen in Hydroponic Growing Medium of Tomato Affects the Demographic Parameters of Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae).

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Hosseini, R S; Madadi, H; Hosseini, M; Delshad, M; Dashti, F

2015-12-01

We evaluated the effects of different nitrogen levels (380, 310, 240, and 174 ppm) on the life history parameters of Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) on hydroponically cultured tomato plants. Our data show that there is a positive correlation between the nitrogen content and the demographic parameters, as the intrinsic rate of increase of T. vaporariorum was the lowest (0.059 ± 0.007 day(-1)) at 174 ppm and the highest (0.088 ± 0.005 day(-1)) at 380 ppm of nitrogen. The net reproduction rate (R 0), finite rate of increase (λ), and mean developmental time (T) were significantly influenced by the nitrogen levels. The mean longevity of males and females showed a positive relationship with the nitrogen level, ranging from 64.8 ± 3.96 to 76.3 ± 2.44 for males and 61.6 ± 5.35 to 71.2 ± 2.44 for females, observed in the lowest and highest nitrogen levels, respectively. The relationship between nitrogen fertilization and T. vaporariorum management on tomato crops is discussed.

Oviposição e dispersão de ninfas de Bemisia tabaci biótipo B em genótipos de tomateiro Oviposition and nymphal dispersion of Bemisia tabaci biotype B on tomato genotypes

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Marilene Fancelli

2008-12-01

Full Text Available Diversos métodos têm sido empregados para avaliar a resistência de plantas a moscas-brancas. Todavia, poucos trabalhos têm sido realizados visando determinar a dispersão de ninfas desses insetos sobre as plantas. O objetivo do presente trabalho foi avaliar a oviposição de B. tabaci biótipo B e a dispersão de suas ninfas em folíolos com e sem exsudatos de genótipos de tomateiro. Foram utilizados sete genótipos de tomateiro: LA716, LA1739, PI134417, LA462, LA1584, 'Santa Clara' e P25 (controle suscetível. A oviposição de B. tabaci biótipo B foi avaliada em gaiolas plásticas (2,8 cm² fixadas na face abaxial dos folíolos, nas quais foram inseridos dez casais do inseto. Para avaliação da dispersão das ninfas, considerou-se o deslocamento dos insetos além do limite da área ocupada pelas gaiolas. As variáveis observadas foram: mortalidade de adultos 24 horas após a liberação, número de ovos, viabilidade da fase de ovo, período de incubação, número de ninfas e dispersão. Em folíolos com exsudato, LA716, LA1739 e PI134417 provocaram as maiores mortalidades. Adultos mortos nos folíolos desses genótipos ficaram aderidos aos tricomas glandulares, o que provocou redução na oviposição do inseto. Para dispersão, nos folíolos com exsudato, os máximos valores ocorreram nos genótipos LA716, LA462 e P25. Na condição sem exsudato, LA716 promoveu a menor dispersão das ninfas. A presença do exsudato influencia negativamente a sobrevivência e oviposição do inseto. A dispersão das ninfas também é afetada pelo exsudato, embora outros fatores possam ser importantes para o deslocamento do inseto.Several methods have been employed for evaluating plant resistance to whiteflies. Although, a few researches have been conducted aiming to determine the whitefly nymphal dispersion on crops. The objective of this work was to evaluate the oviposition of B. tabaci biotype B and nymphal dispersion in leaflets with and without

Physical control possibilities of Bemisia tabaci (Gennadius) and Tomato yellow leaf curl disease (TYLCD) in protected crops

International Nuclear Information System (INIS)

Rapisarda, C.; Cascone, G.; Tropea Garzia, G.; Mazzarella, R.; Colombo, A.; Serges, T.

2005-01-01

Among alternatives to chemical control for reducing virus epidemics in protected tomato crops, physical management of vectors populations through the application of insect-proof screens to greenhouse openings has been investigated since many years and satisfactory results have been obtained so far, especially regarding the incidence of the whitefly Bemisia tabaci (Gennadius), which is the vector of Tomato yellow leaf curl disease (TYLCD). Nevertheless, although effective from the phytosanitary point of view, these insect-proof screens negatively affect the climate inside the greenhouse, by reducing ventilation, increasing air temperature, etc.. Recently, a low incidence of whitefly infestations on crops has been observed inside greenhouses which have been covered with photoselective plastic films absorbing the ultra-violet component (200-380 nm) of solar radiation. The present study, carried out in Sicily by means of three trials during three consecutive years, allowed to evaluate the ability of two different UV-absorbing plastic films to reduce B. tabaci infestations, in comparison to UV-unabsorbing plastic films and insect-proof screens commonly used to cover and protect tomato greenhouses. The results show the good efficiency of both the tested UV-absorbing films to reduce the witefly presence on tomato crops and the consequent TYLCD spreading. Furthermore, it may be observed that UV-absorbing films do not determine sensible variations of greenhouse climate conditions, compared to greenhouses covered with conventional films. These data not only confirm the physical validity of the UV-absorbing films, but also show that they may fit properly within strategies of integrated control of pests and viruses in protected cultivations [it

Side effects of some pesticides on the silverleaf whitefly’s parasitoid, Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae under laboratory conditions

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Mustafa PORTAKALDALI

2015-12-01

Full Text Available The silverleaf whitefly, Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae is one of major pests in greenhouses vegetable cultivation. Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae has an important role among effective parasitoids used in biological control of the silverleaf whitefly. Nondestructive or less destructive pesticides against this parasitoid should be preferred in the scope of biological control. For this goal, side effects of 8 plant protection products, including spinosad, pyriproxyfen, abamectin, emamectin benzoate, copper oxychloride, kresoxim-methyl+boscalid, dimethoate and propineb+cymoxanil on pupae and adults of E. mundus were tested in this laboratory study conducted according to IOBC standards. As a result, pesticides containing spinosad, abamectin and dimethoate were determined as highly destructive to pupae and adults of E. mundus, and pesticide containing emamectin benzoate was found as moderately harmful. As for propineb+cymoxanil, pyriproxyfen, kresoxim-methyl+boscalid and copper oxychloride, they were determined as ineffective on the parasitoid under laboratory conditions. These results obtained from experiments that were conducted under laboratory conditions also have to be supported by field or semi-field experiment’s results.

Aleyrodes proletella (Linnaeaus, 1758) (Homoptera: Aleyrodidae) puede desarrollarse en plantas de tomate en condiciones controladas

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Alonso, D.; Gómez, Azahara A.; Nombela, Gloria; Muñiz, Mariano

2007-01-01

La mosca blanca de la col, Aleyrodes proletella L. causa importantes daños directos en cultivos del género Brassica en Europa, entre los que se incluyen la coliflor, brócoli, lombarda y romanesco. En España se ha observado un incremento de sus poblaciones, especialmente en Islas Canarias, Navarra y Murcia. La aplicación prolongada de plaguicidas de amplio espectro origina la aparición de poblaciones resistentes y efectos medioambientales adversos. Tras una infestación accidental de adult...

Biotype Characterization, Developmental Profiling, Insecticide Response and Binding Property of Bemisia tabaci Chemosensory Proteins: Role of CSP in Insect Defense.

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Guoxia Liu

Full Text Available Chemosensory proteins (CSPs are believed to play a key role in the chemosensory process in insects. Sequencing genomic DNA and RNA encoding CSP1, CSP2 and CSP3 in the sweet potato whitefly Bemisia tabaci showed strong variation between B and Q biotypes. Analyzing CSP-RNA levels showed not only biotype, but also age and developmental stage-specific expression. Interestingly, applying neonicotinoid thiamethoxam insecticide using twenty-five different dose/time treatments in B and Q young adults showed that Bemisia CSP1, CSP2 and CSP3 were also differentially regulated over insecticide exposure. In our study one of the adult-specific gene (CSP1 was shown to be significantly up-regulated by the insecticide in Q, the most highly resistant form of B. tabaci. Correlatively, competitive binding assays using tryptophan fluorescence spectroscopy and molecular docking demonstrated that CSP1 protein preferentially bound to linoleic acid, while CSP2 and CSP3 proteins rather associated to another completely different type of chemical, i.e. α-pentyl-cinnamaldehyde (jasminaldehyde. This might indicate that some CSPs in whiteflies are crucial to facilitate the transport of fatty acids thus regulating some metabolic pathways of the insect immune response, while some others are tuned to much more volatile chemicals known not only for their pleasant odor scent, but also for their potent toxic insecticide activity.

Bemisia tabaci females from the Mediterranean (Q) species detect and avoid laying eggs in the presence of pyriproxyfen, a juvenile hormone analogue.

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Moshitzky, Pnina; Morin, Shai

2014-10-01

Pyriproxyfen, a juvenile hormone analogue, disrupts embryogenesis, metamorphosis and adult formation in Bemisia tabaci, but does not directly affect adult females. The effect of pyriproxyfen on egg-laying preference and performance of B. tabaci females and the influence of resistance to pyriproxyfen on these reproductive behaviours were studied. Choice experiments utilising cotton plants treated and not treated with pyriproxyfen revealed a significant preference for egg laying on non-treated plants both by resistant and susceptible females. No-choice assays indicated a reduction of ∼60% in the number of eggs laid on pyriproxyfen-treated plants by both resistant and susceptible females. The reduction in oviposition on treated plants was not accompanied with reduced expression of the vitellogenin gene or a delay in oocyte maturation, but significant accumulation of mature oocytes in the ovaries was observed, and could be reversed by transferring the females to non-treated plants. Pyriproxyfen caused reduced oviposition and enhanced mature oocyte accumulation in pyriproxyfen-resistant and pyriproxyfen-susceptible females. These findings can be explained by two alternative mechanisms: pyriproxyfen-regulated physiological arrest of oviposition, involving hormonal regulation of myotrophic factors, or the hierarchy-threshold behavioural theory of host choice, in which pyriproxyfen-treated plants are defined as low-quality hosts. Aspects of application are discussed. © 2013 Society of Chemical Industry.

Adubação mineral e orgânica e a densidade populacional de Thrips tabaci Lind. (Thysanoptera: Thripidae em cebola Mineral and organic fertilization and onion thrips, Thrips tabaci Lind. (Thysanoptera: Thripidae population density

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Paulo Antonio de Souza Gonçalves

2004-08-01

Full Text Available O efeito da adubação mineral e orgânica sobre a densidade populacional de Thrips tabaci Lind. em cebola, Allium cepa L., foi avaliado na Estação Experimental de Ituporanga, SC (Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina, entre agosto e dezembro de 1998. Os tratamentos foram níveis de adubação mineral com N, P2O5 e K2O em dose recomendada e três vezes a recomendada, adubação orgânica e a testemunha foi a ausência de adubação. Os tratamentos foram as seguintes doses de nutrientes: 1 30 + 120 + 60kg ha-1 de NPK; 2 90 + 360 + 180kg ha-1 de NPK; 3 75kg ha-1 de N; 4 225kg ha-1 de N; 5 80kg ha-1 de P2O5; 6 240kg ha-1 de P2O5; 7 60kg ha-1 de K2O; 8 180kg ha-1 de K2O; 9 75kg ha-1 de N + 80kg ha-1 de P2O5 (esterco de suíno + fosfato natural; 10 225kg ha-1 de N + 240kg ha-1 de P2O5 (esterco de suíno + fosfato natural; 11 37,5kg ha-1 de N + 40kg ha-1 de P2O5 (esterco de suíno + fosfato natural; testemunha sem adubação. Nenhuma das fontes e níveis de adubação apresentaram nível populacional de T. tabaci superior à testemunha sem adubo.The effect of the mineral and organic fertilization on onion thrips, Thrips tabaci Lind., population density was evaluated at Ituporanga Experiment Station, EPAGRI, Santa Catarina State, Brazil, between August and December 1998. The treatments were different levels of mineral fertilization with N, P2O5 and K2O at recommended rate and three times recommended rate, the organic fertilization and without fertilization was check. The treatments in nutrient rate were: 30 + 120 + 60kg NPK ha-1; 90 + 360 + 180kg NPK ha-1; 75kg N ha-1; 225kg N ha-1; 80kg P2O5 ha-1; 240kg P2O5 ha-1; 60kg K2O ha-1; 180kg K2O ha-1; 75kg N ha-1 + 80kg P2O5 ha-1 (swine manure + phosphate rock; 225kg N + 240kg P2O5 ha-1 (swine manure + phosphate rock; 37,5kg N + 40kg P2O5 ha-1 (swine manure + phosphate rock; check without fertilizer. The onion thrips population density was similar among treatments with

Sequencing and comparison of the Rickettsia genomes from the whitefly Bemisia tabaci Middle East Asia Minor I.

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Zhu, Dan-Tong; Xia, Wen-Qiang; Rao, Qiong; Liu, Shu-Sheng; Ghanim, Murad; Wang, Xiao-Wei

2016-08-01

The whitefly, Bemisia tabaci, harbors the primary symbiont 'Candidatus Portiera aleyrodidarum' and a variety of secondary symbionts. Among these secondary symbionts, Rickettsia is the only one that can be detected both inside and outside the bacteriomes. Infection with Rickettsia has been reported to influence several aspects of the whitefly biology, such as fitness, sex ratio, virus transmission and resistance to pesticides. However, mechanisms underlying these differences remain unclear, largely due to the lack of genomic information of Rickettsia. In this study, we sequenced the genome of two Rickettsia strains isolated from the Middle East Asia Minor 1 (MEAM1) species of the B. tabaci complex in China and Israel. Both Rickettsia genomes were of high coding density and AT-rich, containing more than 1000 coding sequences, much larger than that of the coexisted primary symbiont, Portiera. Moreover, the two Rickettsia strains isolated from China and Israel shared most of the genes with 100% identity and only nine genes showed sequence differences. The phylogenetic analysis using orthologs shared in the genus, inferred the proximity of Rickettsia in MEAM1 and Rickettsia bellii. Functional analysis revealed that Rickettsia was unable to synthesize amino acids required for complementing the whitefly nutrition. Besides, a type IV secretion system and a number of virulence-related genes were detected in the Rickettsia genome. The presence of virulence-related genes might benefit the symbiotic life of the bacteria, and hint on potential effects of Rickettsia on whiteflies. The genome sequences of Rickettsia provided a basis for further understanding the function of Rickettsia in whiteflies. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Insecticide effects of Ruta graveolens, Copaifera langsdorffii and Chenopodium ambrosioides against pests and natural enemies in commercial tomato plantation = Ação inseticida de Ruta graveolens, Copaifera langsdorffii e Chenopodium ambrosioides sobre pragas de tomate

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Flávia Silva Barbosa

2011-01-01

Full Text Available The aim of this study was to evaluate the insecticide effect of watery leaf extracts of Ruta graveolens (Rutaceae, alcoholic leaf extracts of Copaifera langsdorffii (Caesalpinaceae and Chenopodium ambrosioides (Chenopodiaceae in the concentration of 5% under field conditions. The experiment design was randomized blocks with six replications. The parcels treated with plant extracts showed reduction in the population of pests when compared with the controlparcels. The extract elaborated with C. langsdorffii presented greater insecticidal effect under Bemisia tabaci (Hemiptera: Aleyrodidae and sum of pests. It was verified that after 24 hours ofspraying, the parcels treated with the extract of C. ambrosioides presented minor numbers of adults of Tuta absoluta (Lepidoptera: Gelechiidae, followed by the parcels treated with extract of R.graveolens. There were smaller numbers of parasitoid eggs of epidopterans Trichogramma sp. (Hymenoptera: Trichogrammatidae and sum of natural enemies (predators + parasitoids in the parcels that had received spraying with extracts from the plants of C. langsdorffii and C. ambrosioides, followed by R. graveolens, compared to the control. There were a smaller number of parasitoids from the family Eulophidae (Hymenoptera attacking caterpillars of T. absoluta in plants treated with R. graveolens, followed by C. langsdorffii and C. ambrosioides than in the control.O objetivo deste trabalho foi avaliar o efeito inseticida dos extratos aquosos de folhas de Ruta graveolens (Rutaceae e alcoólicos de folhas de Copaifera langsdorffii (Caesalpinaceae e de folhas de Chenopodium ambrosioides (Chenopodiaceae a 5%. O experimento foi em blocos casualizados com seis repetições. As parcelas tratadas tiveram redução na população de pragas, quando comparadas às parcelas sem nenhum tratamento. O extrato elaborado com C. langsdorffii apresentou maior efeito inseticida em Bemisia tabaci (Hemiptera: Aleyrodidae e soma das pragas

Distribution and population development of Nasonovia ribisnigri (Homoptera: Aphididae) in iceberg lettuce.

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Liu, Yong-Biao

2004-06-01

A field study was conducted to determine the distribution and development of aphid Nasonovia ribisnigri (Mosley) (Homoptera: Aphididae) populations in iceberg lettuce, Lactuca sativa L. 'Salinas'. Lettuce plants were transplanted and caged individually in the field and inoculated with apterous N. ribisnigri at 0, 1, 2, 3, and 4 wk after transplanting in spring and fall 2002. Plants were harvested 15-50 d after inoculations; numbers of alates and apterous N. ribisnigri were counted or estimated on each leaf for each plant. Inoculations during all 5 wk of plant development resulted in successful colonization of lettuce heads. Results indicated that head formation did not reduce the risk of colonization by N. ribisnigri to iceberg lettuce; plants were susceptible to colonization by N. ribisnigri throughout their development. For later inoculations, N. ribisnigri populations were relatively smaller, and aphids were found mostly within the heads. For earlier inoculations, N. ribisnigri populations were larger, and within-plant distributions shifted toward frame leaves. The shift of population distributions toward frame leaves correlated significantly with increases in N. ribisnigri population density. For most inoculations, more aphids were present on wrapper leaves than on other leaves. The proportion of alates did not vary significantly with population density. Population development of N ribisnigri also correlated significantly with heat unit accumulation. Yellow sticky cards were used to monitor alates in each cage. Catches of N. ribisnigri alates on yellow sticky cards were significantly correlated with total numbers of alates as well as with total population sizes on individual lettuce plants.

Formation of Stylet Sheaths in āere (in air from eight species of phytophagous hemipterans from six families (Suborders: Auchenorrhyncha and Sternorrhyncha.

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J Kent Morgan

Full Text Available Stylet sheath formation is a common feature among phytophagous hemipterans. These sheaths are considered essential to promote a successful feeding event. Stylet sheath compositions are largely unknown and their mode of solidification remains to be elucidated. This report demonstrates the formation and solidification of in āere (in air produced stylet sheaths by six hemipteran families: Diaphorina citri (Psyllidae, Asian citrus psyllid, Aphis nerii (Aphididae, oleander/milkweed aphid, Toxoptera citricida (Aphididae, brown citrus aphid, Aphis gossypii (Aphididae, cotton melon aphid, Bemisia tabaci biotype B (Aleyrodidae, whitefly, Homalodisca vitripennis (Cicadellidae, glassy-winged sharpshooter, Ferrisia virgata (Pseudococcidae, striped mealybug, and Protopulvinaria pyriformis (Coccidae, pyriform scale. Examination of in āere produced stylet sheaths by confocal and scanning electron microscopy shows a common morphology of an initial flange laid down on the surface of the membrane followed by continuous hollow core structures with sequentially stacked hardened bulbous droplets. Single and multi-branched sheaths were common, whereas mealybug and scale insects typically produced multi-branched sheaths. Micrographs of the in āere formed flanges indicate flange sealing upon stylet bundle extraction in D. citri and the aphids, while the B. tabaci whitefly and H. vitripennis glassy-winged sharpshooter flanges remain unsealed. Structural similarity of in āere sheaths are apparent in stylet sheaths formed in planta, in artificial diets, or in water. The use of 'Solvy', a dissolvable membrane, for intact stylet sheath isolation is reported. These observations illustrate for the first time this mode of stylet sheath synthesis adding to the understanding of stylet sheath formation in phytophagous hemipterans and providing tools for future use in structural and compositional analysis.

Characterization of Phenacoccus solenopsis (Tinsley) (Homoptera: Pseudococcidae) Resistance to Emamectin Benzoate: Cross-Resistance Patterns and Fitness Cost Analysis.

Science.gov (United States)

Afzal, M B S; Shad, S A

2016-06-01

Cotton mealybug Phenacoccus solenopsis (Tinsley) (Homoptera: Pseudococcidae) is a sucking pest of worldwide importance causing huge losses by feeding upon cotton in various parts of the world. Because of the importance of this pest, this research was carried out to select emamectin resistance in P. solenopsis in the laboratory to study cross-resistance, stability, realized heritability, and fitness cost of emamectin resistance. After selection from third generation (G3) to G6, P. solenopsis developed very high emamectin resistance (159.24-fold) when compared to a susceptible unselected population (Unsel pop). Population selected to emamectin benzoate conferred moderate (45.81-fold), low (14.06-fold), and no cross-resistance with abamectin, cypermethrin, and profenofos, respectively compared to the Unsel pop. A significant decline in emamectin resistance was observed in the resistant population when not exposed to emamectin from G7 to G13. The estimated realized heritability (h (2)) for emamectin resistance was 0.84. A high fitness cost was associated with emamectin resistance in P. solenopsis. Results of this study may be helpful in devising insecticide resistance management strategies for P. solenopsis.

Efeito de extratos aquosos de meliáceas sobre Bemisia tabaci biótipo B em tomateiro Effect of aqueous extracts of meliaceous plants on Bemisia tabaci B biotype on tomato plants

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ANTONIO PANCRÁCIO DE SOUZA

2000-01-01

Full Text Available Comparou-se a bioatividade de extratos aquosos a 3% (p/v de três meliáceas, Melia azedarach L. (frutos verdes, Trichilia pallida Swartz (ramos e Azadirachta indica A. Juss (sementes, em relação à mosca branca Bemisia tabaci (Gennadius biótipo B, criada em tomateiro. No primeiro experimento os extratos foram aplicados sobre ovos e sobre ninfas com três dias de idade, avaliando-se a mortalidade e a duração das fases de ovo e de ninfa. No segundo experimento os extratos foram aplicados apenas sobre as ninfas, avaliando-se a mortalidade nessa fase e a longevidade e fecundidade dos adultos. Em relação à fase de ovo, o extrato de T. pallida foi o que provocou maior mortalidade, seguindo-se os de A. indica e M. azedarach. A maior mortalidade ninfal foi constatada com o extrato de A. indica, seguindo-se os de T. pallida e M. azedarach. Nenhum dos extratos afetou a duração das fases de ovo e de ninfa, assim como a longevidade e fecundidade.The objective of this research was to compare the effect of aqueous extracts of fresh fruits of Melia azedarach L., twigs of Trichilia pallida Swartz and seeds of zadirachta indica A. Juss, on eggs and nymphs of silverleaf whitefly Bemisia tabaci (Gennadius B biotype reared on tomato plants. The extracts were tested at a concentration of 3%. In the first experiment, the extracts were applied on eggs and 3-day-old nymphs. Records were taken on mortality, duration of egg and nymphal stages. In the second experiment the extracts were applied on 3-day-old nymphs and records were taken on nymphal mortality, adult longevity and fecundity. The extracts of T. pallida were the most effective on eggs, followed by A. indica and M. azedarach. The extracts of A. indica were the most effective on nymphs followed by T. pallida and M. azedarach. In both experiments, the duration of egg and nymph stages, longevity and fecundity were not affected by the extracts.

Climatic factors and populational dynamics of Mahanarva posticata (Stal-1855) (Homoptera-Cercopidae) as a contribution to a possible regional implantation of the sterile male technique

International Nuclear Information System (INIS)

Oliveira, M.L. de

1981-01-01

A field study on the population dynamics of M. posticata (STAL, 1855) (Homoptera-Cercopidae) was carried out from 1971 to 1978 under the ecological conditions prevailing in the Litoral-Mata-Sul Zone of Pernambuco, Brazil. The results indicated that maximal infestation of the sugar cane crops by the insect generally occured in June and in July, and it was dependent on rainfall, temperature and relative humidity. The population density of adults was decreased markedly during the months of January, February and March. Technical and economical viability of the insect control by the male-sterilization-techniques through radiation was also demonstrated. The technique is to be used isolated or with other conventional procedures in the combat of froghopper infestations in the sugar cane growing in Pernambuco, Brazil. (Author) [pt

INFLUENCIA DE COBERTURAS EN SUELO SOBRE LA SELECCIÓN DEL HOSPEDANTE POR Bemisia tabaci, EN CONDICIONES DE INVERNADERO

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Luko Hilje

2011-01-01

Full Text Available Aunque varios tipos de coberturas en suelo (inertes o vivas pueden reducir la afluencia de adultos de B. tabaci en plantas de tomate, se desconoce el mecanismo específico de acción de cada una de ellas. Por tanto, se realizó un experimento en un invernadero en Turrialba, Costa Rica, para determinar su respuesta tanto a coberturas inertes (metal verde y plástico plateado y amarillo como vivas: maní forrajero (Arachis pintoi, Fabaceae, cinquillo (Drymaria cordata, Caryophyllaceae y culantro (Coriandrum sativum, Umbelliferae. Se les comparó con un testigo (suelo desnudo. Hubo 4 repeticiones de cada tratamiento. Cada cobertura se sembró en una maceta grande, rodeado de una plántula de tomate de 15 cm de altura. Las macetas se colocaron sobre el piso del invernadero, espaciadas 40 cm entre sí. Cada experimento se repitió en 4 días consecutivos, para lo cual los tratamientos se aleatorizaron todos los días. Se utilizó un diseño de parcelas divididas, con las coberturas como la parcela principal y las fechas como las subparcelas. La víspera de cada repetición se liberaron 1200 adultos de B. tabaci (biotipo A en el área experimental y al día siguiente se registraron sus datos tanto en la planta de tomate como en cada cobertura. Los números de adultos fueron mucho mayores (p0,05. Aunque todas interfieren con la habilidad de los adultos para localizar las plantas de tomate, el mecanismo específico de acción difirió según la naturaleza de cada una, excepto en las coberturas vivas, que parecen compartir el mismo mecanismo.

The broadly insecticidal Photorhabdus luminescens toxin complex a (Tca): Activity against the Colorado potato beetle, Leptinotarsa decemlineata, and sweet potato whitefly, Bemisia tabaci

OpenAIRE

Blackburn, Michael B.; Domek, John M.; Gelman, Dale B.; Hu, Jing S.

2005-01-01

Toxin complex a (Tca), a high molecular weight insecticidal protein complex produced by the entomopathogenic bacterium Photorhabdus luminescens, has been found to be orally toxic to both the Colorado potato beetle, Leptinotarsa decemlineata, and the sweet potato whitefly, Bemisia tabaci biotype B. The 48 hour LC50 for Tca against neonate L. decemlineata was found to be 2.7 ppm, and the growth of 2nd instar L. decemlineata exposed to Tca for 72 hours was almost entirely inhibited at concentrat...

The sterile insect technique in the integrated pest management of whitefly species in greenhouses

International Nuclear Information System (INIS)

Calvitti, M.; Remotti, P.C.; Cirio, U.

2000-01-01

Insect pests commonly known as whiteflies are Hemiptera belonging to the family of Aleyrodidae Trialeurodes vaporariorum Westwood (greenhouse whitefly) and the B-biotype of Bemisia tabaci Gennadius (=Bemisia argentifolii Bellows and Perring) are pests whose economic importance is constantly increasing within the European agriculture. The B-biotype of B. tabaci, in particular, has become more problematic by causing damage over a wide range, from the temperate climates of Californian squash fields to European greenhouses and field crops. In the absence of valid alternatives, many growers have resorted to intensive application of insecticides to control these pests, creating a severe environmental and health hazard. Several new environmentally safe technologies are currently available and have opened up new opportunities in the integrated pest management (IPM) of whiteflies under greenhouse conditions. In particular, biological or biologically-based control means, including a number of fungi, insects, and compounds have been recently developed. However, the limitation of whitefly population outbreaks in greenhouses is a problem that needs to be solved. The idea to extend the use of sterile insect technique (SIT) to a confined environment against whitefly species is novel, and especially when we consider that the target species undergo arrhenotoky (unfertilised females generate only male progenies). The possibility to join this approach to the Integrated Pest Management (IPM) of the whitefly species in the greenhouse may open new perspectives in the safe application of nuclear technology for pest control. The present work reviews recent advances in research and practice related to the development of SIT for the control of whiteflies in greenhouses. Explanations on whitefly radiation biology, with data on Bemisia spp. radio-sterilisation, methods for whitefly mass rearing and collection, and the definition of a complete SIT procedure tested against the greenhouse

Use of biorational for the vegetable pest control in the north of Sinaloa

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María Berenice González Maldonado

2012-09-01

Full Text Available In Sinaloa the vegetable and cucurbits production are important agricultural activities, so each year a high volume of chemicalinsecticides are applied to pest control that attack these crops. This paper present the main pests insects in the region, as wellas an analysis about effects of biorational insecticides on these pests. Was found that for control of Bemisia argentifolii Bellows & Perring (Hemiptera: Aleyrodidae is used Neem oil 0.2%., for kill nymphs of Bactericera cockerelli Sulc. (Homoptera: Psyllidae soursop Annona muricata L. (Annonales: Annonaceae at doses of 2500-5000 mg/L., for Liriomyza trifolii Burgess (Diptera: Agromyzidae neem seeds 2%., to Myzus persicae Sulzer (Hemiptera: Aphididae rapeseed oil at doses 920 g/L (2% v/v., to Frankliniella occidentalis Pergande (Thysanoptera: Thripidae spinosad (Conserve® 48-60 mg/L., and for Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae granular viruses (105 OBs/mL combined with neem (DalNeem TM emulsifiable oil and NeemAzal TM -T/S at doses of 8 mg/L, everyone. The use of these products and the dose depends on the type of pest and crop. In general these products cause insect mortality greater than 95%, besides having low toxicity on natural enemies, so that these can be used individually or in combination in integrated pest control schemes against vegetable pests, and also for disease vectors insects in the northern of Sinaloa.

Molecular systematics of aphids (Homoptera: Aphididae): new insights from the long-wavelength opsin gene.

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Ortiz-Rivas, Benjamín; Moya, Andrés; Martínez-Torres, David

2004-01-01

Viviparous aphids (Aphididae) constitute a monophyletic group within the Homoptera with more than 4000 extant species worldwide but higher diversity in temperate regions. Several aspects of their biology account for attention paid to this group of insects. Their plant-sap-sucking way of feeding with many species transmitting viruses to crop plants has important implications on crop management strategies. Cyclical parthenogenesis associated in many groups to host alternation and elaborate polyphenisms is of special interests for evolutionists. Finally, the ancient association of most aphid species with intracellular endosymbiotic bacteria (Buchnera sp.) has also received much attention from evolutionists interested in mechanisms involved in the symbiotic process. Knowing the phylogenetic relationships among major aphid taxa is of special interest to evolutionists interested in the above issues. However, until recently, molecular approaches to aphid phylogeny were absent and discussions on the evolution of aphid life-cycles and on evolutionary aspects of their symbiotic association with Buchnera were framed by morphology-based phylogenies. Recently, two reports using molecular approaches attempted to address the yet unresolved phylogeny of Aphididae with limited although somehow different conclusions. In the present report we study the utility of the long-wave opsin gene in resolving phylogenetic relationships among seven subfamilies within the Aphididae. Our results corroborate some previously proposed relationships and suggest a revision of some others. In particular, our data support grouping the analysed aphid species into three main clades, being the subfamily Lachninae one of them, which contradicts its generally accepted sistership relationship with the subfamily Aphidinae. Moreover, our data also suggest a basal position of Lachninae which has implications on current discussions about the ancestrality of conifer-feeding in modern aphids.

Factors affecting herbivory of Thrips palmi (Thysanoptera: Thripidae and Aphis gossypii (Homoptera: Aphididae on the eggplant (Solanum melongena

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Germano Leão Demolin Leite

2006-05-01

Full Text Available The objective of this study was to evaluate effects of total rainfall, mean temperature, natural enemies, chemical composition of leaves, levels of nitrogen and potassium on leaves and density of leaf trichomes on attack intensity of Thrips palmi Karny (Thysanoptera: Thripidae and Aphis gossypii (Glover (Homoptera: Aphididae on plantations of the eggplant (Solanum melongena in two regions of Minas Gerais, Brazil. Higher numbers of A. gossypii/leaf and T. palmi/leaf were observed in plantations of this eggplant in the Municipalities of Viçosa and Guidoval, respectively. Guidoval had a rainy and hotter weather than Viçosa. T. palmi was almost positivelly correlated with rainfall (r= 0.49, P= 0.0538 while A. gossypii seemed to be more affected by mean temperature (r= -0.31; P= 0.1134. Higher number of aphids in eggplants in Viçosa than in Guidoval could be explained by the higher number of natural enemies such as Adialytus spp. (Hymenoptera: Braconidae, Cycloneda sanguinea (L. and Exochomus bimaculosus Mulsant (Coleoptera: Coccinellidae and Chrysoperla spp. (Neuroptera: Chrysopidae in this municipality. However, only Adialytus spp. was significativelly correlated with aphid populations. Higher number of T. palmi in eggplant plantations of Guidoval than in Viçosa could be due to the absence of its possible Eulophidae parasitoid in the first municipality. The spiders were significativelly correlated with this pest in both municipalities.O objetivo deste estudo foi avaliar os efeitos de pluviosidade total, temperatura média, inimigos naturais, composição química foliar, níveis de nitrogênio e potássio foliar e densidade de tricomas na intensidade de ataque de Thrips palmi Karny (Thysanoptera: Thripidae e Aphis gossypii (Glover (Homoptera: Aphididae em plantações de berinjela (Solanum melongena em dois municípios de Minas Gerais, Brasil. Observou-se maiores números de A. gossypii e T. palmi por folha em plantações de berinjela nos

Spatial pattern detection modeling of thrips (Thrips tabaci on onion fields Detecção de padrões espaciais na ocorrência do tripes (Thrips tabaci na cultura da cebola

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Paulo Justiniano Ribeiro Jr

2009-02-01

Full Text Available Onion (Allium cepa is one of the most cultivated and consumed vegetables in Brazil and its importance is due to the large laborforce involved. One of the main pests that affect this crop is the Onion Thrips (Thrips tabaci, but the spatial distribution of this insect, although important, has not been considered in crop management recommendations, experimental planning or sampling procedures. Our purpose here is to consider statistical tools to detect and model spatial patterns of the occurrence of the onion thrips. In order to characterize the spatial distribution pattern of the Onion Thrips a survey was carried out to record the number of insects in each development phase on onion plant leaves, on different dates and sample locations, in four rural properties with neighboring farms under different infestation levels and planting methods. The Mantel randomization test proved to be a useful tool to test for spatial correlation which, when detected, was described by a mixed spatial Poisson model with a geostatistical random component and parameters allowing for a characterization of the spatial pattern, as well as the production of prediction maps of susceptibility to levels of infestation throughout the area.A cebola é uma das hortaliças mais cultivadas e consumidas no Brasil e sua importância social se deve à grande demanda por mão-de-obra. Uma das principais pragas que afeta essa cultura é o tripes do prateamento (Thrips tabaci e sua distribuição espacial, embora importante, não tem sido considerada nas recomendações de manejo da cultura, planejamento de experimentos ou estudos amostrais. O objetivo desse artigo foi considerar métodos estatísticos para detectar e modelar padrões espaciais na ocorrência do tripes do prateamento da cebola. Para caracterizar o padrão espacial da dispersão do tripes do prateamento da cebola foi feito um levantamento anotando-se o número de insetos por fase de desenvolvimento em folhas de plantas de

Population Growth of Rhopalosiphum padi L. (Homoptera: Aphididae on Different Cereal Crops from the Semiarid Pampas of Argentina under Laboratory Conditions Crecimiento Poblacional de Rhopalosiphum padi L. (Homoptera: Aphididae sobre Diferentes Cereales de la Pampas Semiárida de Argentina en Condiciones de Laboratorio

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Lilian R Descamps

2011-09-01

Full Text Available The bird cherry-oat aphid Rhopalosiphum padi L. (Homoptera: Aphididae is one of the main pests in a number of crops in the semiarid Pampas of Argentina. In the present study, the effect of different host plants, including Triticum aestivum L., ×Triticosecale Wittm., Hordeum vulgare L., Hordeum distichum L., Avena sativa L., and Secale cereale L. on biological parameters of R. padi L. was studied in the laboratory at 24 ± 1 °C, 65 ± 10% RH and a 14:10 photoperiod. Longevity, intrinsic rate of natural increase (r m, net reproductive rate (R0, mean generation time (T, doubling time (DT, and finite rate of increase (λ of the bird cherry-oat aphid on the different cereal crops were estimated. Differences in fertility life table parameters of R. padi among host plants were analyzed using pseudo-values, which were produced by Jackknife re-sampling. Results indicated that beer barley might be the most suitable food for R. padi due to greater adult longevity (20.88 d, higher fecundity (41 nymphs female-1, higher intrinsic rate of natural increase (0.309 females female-1 d-1, lower doubling time (2.24, and lower nymphal mortality (22.2%. Therefore, it can be concluded from the present study that R. padi prefers beer barley for fast and healthy development over other cereal crops.El áfido Rhopalosiphum padi L. (Homoptera: Aphididae es una de las principales plagas de numerosos cultivos de la región semiárida pampeana de Argentina. En el presente trabajo se estudió el efecto de diferentes cereales incluidos Triticum aestivum L., ×Triticosecale Wittm., Hordeum vulgare L., Hordeum distichum L., Avena sativa L. and Secale cereale L. sobre los parámetros biológicos de R. padi en laboratorio. Se estimaron longevidad, tasa intrínseca de crecimiento natural (r m, tasa neta de reproducción (R0, tiempo generacional medio (T, tiempo de duplicación (TD, y tasa finita de incremento (λ del pulgón de la avena en diferentes cereales. Las diferencias de

INSETICIDAS APLICADOS VIA TRATAMENTO DE SEMENTES VISANDO AO CONTROLE DAS MOSCAS BRANCAS (Bemisia tabaci, GENN. E MINADORA (Liriomyza sp. NA CULTURA DO FEIJOEIRO CHEMICAL CONTROL OF THE WHITE FLY Bemisia tabaci GENN. AND LEAFMINER Liriomyza sp. IN BEAN CROPS BY SEED TREATMENTS

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Antônio Lopes da Silva

2007-09-01

Full Text Available

Realizou-se o presente experimento no campo experimental da Escola de Agronomia da Universidade Federal de Goiás, de março a maio de 1993, para avaliar o controle das moscas brancas (Bemisia tabaci, GENN. e minadora (Liriomyza sp. na fase inicial da cultura do feijoeiro, com produtos aplicados via tratamento de sementes. Os tratamentos constaram de: imidacloprid 700 PM nas dosagens de 140, 210, 280 e 350 gramas de ingrediente ativo (i.a/l00 kg de sementes; carbosulfan + zinco 250 TS nas dosagens de 375 e 500g i.a./100kg de sementes, comparados com o carbofuran 350 TS na dosagem de 525 g i.a./100kg de sementes (padrão. Pelos resultados, concluiu-se que todos os tratamentos foram eficientes no controle da mosca minadora, com porcentagens de eficiência que variaram de 93 a 99%. Imidacloprid, a partir de 280g i.a./100kg de sementes, foi igual aos outros produtos em eficiência no controle da mosca branca, com porcentagens de controle variando entre 83 a 89%.

A trial to control the white fly Bemisia tabaci, GENN. and leafminer Liriomyza sp. was carried out in Goiânia, state of Goiás. The treatments and dosages of the insecticides per 100kg of seed were: imidacloprid (140, 210, 280 and 350g a.i., carbofuran (525 g a.i., carbosulfan (375 and 500g a.i, plus an untreated check. The application of the treatments were made on the seeds. The results of the experiment showed that all insecticides were efficient in controlling the leafminer at all dosages tested and imidacloprid at the dosages of 280 and 350g a.i. per 100kg seed was similar in controlling the white fly in bean crops.

Influence des facteurs écologiques (température et hygrométrie sur le développement de la cochenille farineuse du manioc (Phenacoccus manihoti Matile-Ferrero, Homoptera: Pseudococcidae

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Obame Minko, D.

2009-01-01

Full Text Available The Influence of Ecological Factors (such as Temperature and Hygrometry on the Development of Cassava Mealybug (Phenacoccus manihoti Matile-Ferrero, Homoptera: Pseudococcidae. Phenacoccus manihoti Matile-Ferrero cassava mealybug was accidentally carried away from South America to Africa by early 70s. Since then, it has been inducing a lot of damage to cassava cultures, which cassava remains the main foodstuff in the southern Sahara inhabitant's nutrition. Being anxious to understand the depredator population evolution in the nature, we have studied the temperature and hygrometry as main ecological factors helpful to development. The temperature favours eggs hatching and reduces the duration of embryonic, larval and cycle development whereas hygrometry's action on mealybug development can be neglected. As both factors are opposite functions in the nature, mutual influence on the field can be possible.

RNAi-mediated resistance to whitefly (Bemisia tabaci) in genetically engineered lettuce (Lactuca sativa).

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Ibrahim, Abdulrazak B; Monteiro, Tatiane R; Cabral, Glaucia B; Aragão, Francisco J L

2017-10-01

RNA interference (RNAi)-based transgenic technologies have evolved as potent biochemical tools for silencing specific genes of plant pathogens and pests. The approach has been demonstrated to be useful in silencing genes in insect species. Here, we report on the successful construction of RNAi-based plasmid containing an interfering cassette designed to generate dsRNAs that target a novel v-ATPase transcript in whitefly (Bemisia tabaci), an important agricultural pest in tropical and sub-tropical regions. The presence of the transgene was confirmed in T 0 and T 1 generations of transgenic lettuce lines, segregating in a Mendelian fashion. Seven lines were infested with whiteflies and monitored over a period of 32 days. Analysis of mortality showed that within five days of feeding, insects on transgenic plants showed a mortality rate of 83.8-98.1%. In addition, a reduced number of eggs (95 fold less) was observed in flies feeding on transgenic lettuce plants than insects on control lines. Quantitative reverse transcription PCR showed decreased expression level of endogenous v-ATPase gene in whiteflies feeding on transgenic plants. This technology is a foundation for the production of whitefly-resistant commercial crops, improving agricultural sustainability and food security, reducing the use of more environmentally aggressive methods of pest control.

Ocorrência de Tuthillia cognata Hodkinson, Brown & Burckhardt, 1986(Hemiptera: Homoptera, Psyllidae em plantios experimentais de camu-camu Myrciaria dubia (H.B.K. Mc Vaugh em Manaus (Amazonas, Brasil Occurrence of Tuthillia cognata Hodkinson, Brown & Burckhardt, 1986 (Hemiptera: Homoptera, Psyllidae in experimental plantations of camu-camu Myrciaria dubia (H.B.K. Mc Vaugh in Manaus (Amazonas, Brazil

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Márcio Luís Leitão Barbosa

2004-01-01

Full Text Available O cultivo de camu-camu Myrciaria dubia (H.B.K. Mc Vaugh tem apresentado inúmeros problemas fitossanitários, dentre os quais, Tuthillia cognata Hodkinson et al. (Hemiptera: Homoptera, Psyllidae, que constantemente é citada como praga secundária. Os objetivos deste estudo foram determinar o nível e a intensidade de infestação (% por T. cognata e estudar aspectos do ciclo biológico e do comportamento de T. cognata, em plantios experimentais de camu-camu. Foram selecionados, de forma aleatória, 17 e 14 exemplares nos plantios I e II, respectivamente. Para cada uma das variáveis estudadas, foram calculados a média aritmética, o desviopadrão, a variância e a amplitude de variação. Foi verificado um nível de infestação de 82% (plantio I e 57% (plantio II, uma intensidade de infestação de 94% (plantio I e 75% (plantio II e uma média de seis ninfas/folha em cada plantio, o que indica que T. cognata representa uma das pragas-chave dessa cultura. Foram observados adultos de Chrysoperla sp. (Neuroptera: Chrysopidae e ninfas de Reduviidae (Hemiptera: Heteroptera, que podem atuar como prováveis agentes de controle biológico de T. cognata.The cultivation of camu-camu Myrciaria dubia (H.B.K. Mc Vaugh has presented countless phytosanitary problems, among them, Tuthillia cognata Hodkinson et al. (Hemiptera: Homoptera, Psyllidae, which often is noticed as a secondary pest. This study aimed to determine the level and the intensity of infestation (% for T. cognata, as well as to study the biological cycle and behavioural aspects of T. cognata, in experimental plantation of camu-camu. 17 and 14 specimens from plantation I and II, respectively, were randomly selected. The arithmetic average, the standard deviation, the variance and the total amplitude were calculated for each studied variable. A level of infestation of 82% (plantation I and 57% (plantation II, an intensity of infestation of 94% (plantation I and 75% (plantation II and an

Effect of Zohar LQ-215, a biorational surfactant, on the sweetpotato whitefly Bemisia tabaci (biotype b).

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Ishaaya, I; Khasdan, V; Horowitz, A Rami

2006-01-01

Zohar LQ-215, a surfactant based on plant oils, able to control nymphs of the whitefly, Bemisia tabaci (Gennadius), under laboratory and field conditions. To evaluate the effects of the surfactant on the nymph stages of whitefly under laboratory conditions, potted cotton seedlings infested with 1st- or 3rd-instars were treated with the compound aqueous solutions. LC90 values of Zohar LQ-215 on 1st and 3rd-nymphs, based on mortality curves, were 0.78% and 1.14%, respectively. Adult mortality of 12% and 19% was obtained at concentrations of 0.5% and 1%, respectively. Under both laboratory and, in some cases, under field conditions, greater mortality was achieved when combining Zohar LQ-215 with the insect growth regulator buprofezin than when either insecticide was applied separately. Our results indicate that Zohar LQ-215 could serve as a potential compound for controlling whiteflies under light to moderate infestation and could be used in combination with other rational insecticides such as buprofezin for controlling whiteflies in integrated pest management programs.

Potential damages, seasonal abundance and distribution of Empoasca terminalis Distant (Homoptera: Cicadellidae on soybean in South Sulawesi

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Andi Nasruddin

2015-09-01

Full Text Available Plant damages caused by leafhopper, Empoasca terminalis Distant (Homoptera: Cicadellidae on soybean were first encountered in 2007 in Makassar, South Sulawesi. The insect has been constantly associated with soybean crops in the province ever since. The purposes of the present study were to (i evaluate potential yield loss attributable to the leafhopper in an experimental set up, (ii seasonal abundance of E. terminalis, and (iii distribution of E. terminalis in all major soybean-producing areas in the province. Potential yield loss due to the leafhopper was assessed in a field experiment using two large plots. One of the plots was kept leafhopper-free by weekly insecticide sprays; and the other plot was left unsprayed to allow leafhopper infestation to occur. Adult abundance was weekly monitored using a sweep net throughout the season. Nymph abundance was determined by direct count on the plant leaves. Leafhopper distribution was assessed through surveys conducted in all major soybean-producing areas in South Sulawesi, from 2009–2013. The results of the study showed that E. terminalis caused an average yield loss of 26% on susceptible crops without insecticide use. First leafhopper infestation in all planting seasons occurred two weeks after the plant emergence. Rainfall negatively correlated with the leafhopper abundance. The leafhopper existed in all major soybean production areas in the province. Therefore, our results confirmed the status of E. terminalis as an important soybean pest in the region. In addition, crops planted early in the dry season could escape from heavy leafhopper infestation.

Consequences of co-applying insecticides and fungicides for managing Thrips tabaci (Thysanoptera: Thripidae) on onion.

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Nault, Brian A; Hsu, Cynthia L; Hoepting, Christine A

2013-07-01

Insecticides and fungicides are commonly co-applied in a tank mix to protect onions from onion thrips, Thrips tabaci Lindeman, and foliar pathogens. Co-applications reduce production costs, but past research shows that an insecticide's performance can be reduced when co-applied with a fungicide. An evaluation was made of the effects of co-applying spinetoram, abamectin and spirotetramat with commonly used fungicides, with and without the addition of a penetrating surfactant, on onion thrips control in onion fields. Co-applications of insecticides with chlorothalonil fungicides reduced thrips control by 25-48% compared with control levels provided by the insecticides alone in three of five trials. Inclusion of a penetrating surfactant at recommended rates with the insecticide and chlorothalonil fungicide did not consistently overcome this problem. Co-applications of insecticides with other fungicides did not interfere with thrips control. Co-applications of pesticides targeting multiple organisms should be examined closely to ensure that control of each organism is not compromised. To manage onion thrips in onion most effectively, insecticides should be applied with a penetrating surfactant, and should be applied separately from chlorothalonil fungicides. © 2012 Society of Chemical Industry.

Laboratory Study of The Effect of Lemongrass Leaves Cymbopogon citratus on An Onion Thrips Insect Thrips tabaci (Thripidae: Thysanoptera

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Ather A. Mohsin

2018-03-01

Full Text Available This laboratory study was carried out to test the effect of the extracts of ethanol, chloroform, volatile oil and emulsifier of Cymbopogon citratus in killing the adults of the thrips tabaci. The concentrations 250, 500 and 1000 ppm. The results showed that the highest percentage of killed in Volatile oil with a concentration of 1000 ppm at 60.00, 63.33, 66.66, 70 and 76.66% for the first, second, third, fifth and seventh days of control and the lowest percentage was for the emulsifier at 30.00, 36.66, 46.66, 53.33 and 63.33% for the first and second, third, fifth and seventh days of the control, respectively, and we noticed that the higher the concentrations, the higher the percentage of killings and the increase in the percentage of killings cumulatively, as it was the highest percentage of killing on the seventh day.

Phylogenetic position of the yeast-like symbiotes of Tagosodes orizicolus (Homoptera: Delphacidae based on 18S ribosomal DNA partial sequences

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Ana M Xet-Mull

2004-09-01

Full Text Available Tagosodes orizicolus Muir (Homoptera: Delphacidae, the endemic delphacid species of tropical America carries yeast-like symbiotes (YLS in the abdominal fat bodies and the ovarial tissues, like other rice planthoppers of Asia. These YLS are obligate symbiotes, which are transmitted transovarially, and maintain a mutualistic relationship with the insect host. This characteristic has made in vitro culture and classification of YLS rather difficult using conventional methods. Nevertheless, microorganisms of similar characteristics have been successfully classified by using molecular taxonomy. In the present work, the YLS of Tagosodes orizicolus(YLSTo were purified on Percoll® gradients, and specific segments of 18S rDNA were amplified by PCR, cloned and sequenced. Sequences were aligned by means of the CLUSTAL V (DNASTAR program; phylogenetic trees were constructed with the Phylogeny Inference Package (PHYLIP, showing that YLSTo belong to the fungi class Pyrenomycetes, phylum Ascomycota. Similarities between 98% and 100% were observed among YLS of the rice delphacids Tagosodes orizicolus, Nilaparvata lugens, Laodelphax striatellus and Sogatella furcifera, and between 89.8% and 90.8% when comparing the above to YLS of the aphid Hamiltonaphis styraci. These comparisons revealed that delphacid YLS are a highly conserved monophyletic group within the Pyrenomycetes and are closely related to Hypomyces chrysospermus. Rev. Biol. Trop. 52(3: 777-785. Epub 2004 Dic 15.Tagosodes orizicolus Muir (Homoptera: Delphacidae es una especie endémica de América tropical que al igual que otros saltahojas de Asia, tiene simbiontes levaduriformes (YLS, por sus siglas en Inglés en los cuerpos grasos del abdomen y en los tejidos de los ovarios. Los YLS son simbiontes obligados que se transmiten transovarialmente y que mantienen relaciones mutualística con el insecto hospedero. Esta característica ha hecho muy difícil su cultivo in vitro y por ende su clasificaci

Compatibilidad in vitro de Isaria fumosorosea (Wize Brown y Smith (Hypocreales: Clavicipitaceae con plaguicidas comerciales

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Érika Paola Grijalba Bernal

2014-01-01

Full Text Available Los agricultores colombianos utilizan productos químicos con categorías toxicológicas I, II y III para el control de insectos como la mosca blanca Bemisia tabaci (Gennadius, 1889 (Hemiptera: Aleyrodidae; pero su uso indiscriminado genera un riesgo para la salud y el medio ambiente. El control microbiológico con hongos entomopatógenos surge como alternativa de control ambientalmente sostenible. No obstante, su empleo exitoso dentro de una estrategia de manejo integrado de plagas (MIP depende, en gran parte, del efecto de los productos químicos sobre el bioplaguicida. El objetivo del presente trabajo fue determinar la compatibilidad in vitro de un bioplaguicida con base en el hongo Isaria fumosorosea formulado como polvo mojable con cuatro fungicidas y cinco insecticidas comerciales. Para esto, se evaluó el efecto de tres concentraciones de los productos químicos: FR = dosis recomendada en campo, 0.5 x FR y 0.25 x FR sobre la germinación de los conidios y el número de unidades formadoras de colonia UFC/g de I. fumosorosea. Los cuatro fungicidas (Benlate, Carboxin Captan, Metalaxil-Mancozeb y Mancozeb en las tres dosis evaluadas fueron incompatibles con el bioplaguicida, mientras que el insecticida Thiametoxam fue compatible cuando se utilizó la dosis de 0.25 x FR.

Electrostatic Insect Sweeper for Eliminating Whiteflies Colonizing Host Plants: A Complementary Pest Control Device in An Electric Field Screen-Guarded Greenhouse.

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Takikawa, Yoshihiro; Matsuda, Yoshinori; Kakutani, Koji; Nonomura, Teruo; Kusakari, Shin-Ichi; Okada, Kiyotsugu; Kimbara, Junji; Osamura, Kazumi; Toyoda, Hideyoshi

2015-05-12

Our greenhouse tomatoes have suffered from attacks by viruliferous whiteflies Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) over the last 10 years. The fundamental countermeasure was the application of an electric field screen to the greenhouse windows to prevent their entry. However, while the protection was effective, it was incomplete, because of the lack of a guard at the greenhouse entrance area; in fact, the pests entered from the entrance door when workers entered and exited. To address this, we developed a portable electrostatic insect sweeper as a supplementary technique to the screen. In this sweeper, eight insulated conductor wires (ICWs) were arranged at constant intervals along a polyvinylchloride (PVC) pipe and covered with a cylindrical stainless net. The ICWs and metal net were linked to a DC voltage generator (operated by 3-V alkaline batteries) inside the grip and oppositely electrified to generate an electric field between them. Whiteflies on the plants were attracted to the sweeper that was gently slid along the leaves. This apparatus was easy to operate on-site in a greenhouse and enabled capture of the whiteflies detected during the routine care of the tomato plants. Using this apparatus, we caught all whiteflies that invaded the non-guarded entrance door and minimized the appearance and spread of the viral disease in tomato plants in the greenhouse.

Toxicity of neem oil to Bemisia tabaci biotype B nymphs reared on dry bean Toxicidade de óleo de nim para ninfas de Bemisia tabaci biótipo B criadas em feijoeiro

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Patricia Valle Pinheiro

2009-04-01

Full Text Available The objective of this work was to determine the most susceptible nymphal stage of Bemisia tabaci biotype B to neem (Azadirachta indica A. Juss. oil applied to dry bean (Phaseolus vulgaris L. in a screenhouse. A solution of commercial oil (Dalneem extracted from neem seeds was sprayed directly on each nymphal instar at 0, 0.1, 0.25, 0.5, 1 and 2% concentrations for lethal concentration (LC determination, and at 0, 0.5 and 1% concentrations for lethal time (LT determination. The number of living and dead nymphs was recorded five days after spraying for LC determination, and daily during six days for LT determination. The LC50 estimated for fourth instar nymphs occurred at 0.56% concentration. For all instars, LC50 and LC95 were estimated at 0.32 and 2.78% concentrations, respectively. The estimated values of LT50 at 1% concentration were 2.46, 4.45, 3.02 and 6.98 days for the first to fourth instars, respectively. The LT50 occurred at five days for 0.5% and at four days for 1% concentration in all instars. A mortality rate of over 80% was observed on the 6th day for the first to third instars at 1% concentration. The first three nymphal stages were more susceptible to neem oil when compared to the fourth nymphal stage.O objetivo deste trabalho foi determinar o estágio ninfal de Bemisia tabaci biótipo B mais suscetível ao óleo de nim (Azadirachta indica A. Juss. aplicado em feijoeiro (Phaseolus vulgaris L., em casa telada. Foram avaliados o tempo letal (TL e concentração letal (CL do óleo comercial de sementes de nim Dalneem. Para CL, concentrações de 0, 0,1, 0,25, 0,5, 1 e 2% do produto foram pulverizadas diretamente sobre as ninfas em cada ínstar. Para TL, o produto foi avaliado a 0, 0,5 e 1% de óleo de nim em cada ínstar. Ninfas vivas e mortas foram contadas cinco dias após a pulverização para CL e diariamente para TL durante seis dias. Para o quarto ínstar, a CL50 foi de 0,56% de óleo de nim. Considerando todos os ínstares, CL

Leaf endophytic fungi of chili (Capsicum annuum and their role in the protection against Aphis gossypii (Homoptera: Aphididae

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HENY HERNAWATI

2011-10-01

Full Text Available Hernawati H, Wiyono S, Santoso S (2011 Leaf endophytic fungi of chili (Capsicum annuum and their role in the protection against Aphis gossypii (Homoptera: Aphididae. Biodiversitas 12: 187-191. The objectives of the research were to study the diversity of leaf endophytic fungi of chili, and investigate its potency in protecting host plants against Aphis gossypii Glov. Endophytic fungi were isolated from chili leaves with two categories: aphid infested plants and aphid-free plants, collected from farmer’s field in Bogor, West Java. Abundance of each fungal species from leave samples was determined by calculating frequency of isolation. The isolated fungi were tested on population growth of A. gossypii. The fungal isolates showed suppressing effect in population growth test, was further tested on biology attributes i.e. life cycle, fecundity and body length. Five species of leaf endophytic fungi of chili were found i.e. Aspergillus flavus, Nigrospora sp., Coniothyrium sp., and SH1 (sterile hypha 1, SH2 (sterile hypha 2. Eventhough the number of endophytic fungi species in aphid-free and aphid-infested plant was same, the abundance of each species was different. Nigrospora sp., sterile hyphae 1 and sterile hyphae 2 was more abundant in aphid-free plants, but there was no difference in dominance of Aspergillus flavus and Coniothyrium sp. Nigrospora sp., SH1 and SH2 treatment reduced significantly fecundity of A. gossypii. Only SH2 treatment significantly prolonged life cycle and suppress body length, therefore the fungus had the strongest suppressing effect on population growth among fungi tested. The abundance and dominance of endophytic fungal species has relation with the infestation of A. gossypii in the field.

Pathogenicity of Two Species of Entomopathogenic Nematodes Against the Greenhouse Whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), in Laboratory and Greenhouse Experiments.

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Rezaei, Nastaran; Karimi, Javad; Hosseini, Mojtaba; Goldani, Morteza; Campos-Herrera, Raquel

2015-03-01

The greenhouse whitefly Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) is a polyphagous pest in greenhouse crops. The efficacy of two entomopathogenic nematodes (EPN), Steinernema feltiae and Heterorhabditis bacteriophora, as biological control agents against T. vaporariorum was evaluated using two model crops typical of vegetable greenhouse productions: cucumber and pepper. Laboratory tests evaluated adults and second nymphal instars for pest susceptibility to different EPN species at different concentrations of infective juveniles (IJ; 0, 25, 50, 100, 150, 200, and 250 IJ per cm(2)); subsequent greenhouse trials against second nymphal instars on cucumber and pepper plants evaluated more natural conditions. Concentrations were applied in combination with Triton X-100 (0.1% v/v), an adjuvant for increasing nematode activity. In laboratory studies, both life stages were susceptible to infection by the two nematode species, but S. feltiae recorded a lower LC50 than H. bacteriophora for both insect stages. Similarly, in greenhouse experiments, S. feltiae required lower concentrations of IJ than H. bacteriophora to reach the same mortality in nymphs. In greenhouse trials, a significant difference was observed in the triple interaction among nematode species × concentration × plant. Furthermore, the highest mortality rate of the second nymphal instars of the T. vaporariorum was obtained from the application of S. feltiae concentrated to 250 IJ/cm(2) on cucumber (49 ± 1.23%). The general mortality caused by nematodes was significantly higher in cucumber than in pepper. These promising results support further investigation for the optimization of the best EPN species/concentration in combination with insecticides or adjuvants to reach a profitable control of this greenhouse pest.

Inter-regional differences in baseline toxicity of Bemisia argentifolii (Homoptera: Aleyrodidae) to the two insect growth regulators, buprofezin and pyriproxyfen.

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Toscano, N C; Prabhaker, N; Castle, S J; Henneberry, T J

2001-12-01

A survey of 53 Bemisia argentifolii Bellows & Perring populations from different agricultural regions in California and Arizona was conducted from 1997 to 1999 to establish baseline toxicological responses to buprofezin and pyriproxyfen. Although both compounds proved to be highly toxic even in minute quantities to specific stages, geographical and temporal differences in responses were detected using a leaf spray bioassay technique. Monitoring for three years revealed that six to seven populations had higher LC50 values but not greater survival when exposed to these two insecticides. A significant difference in relative susceptibility to buprofezin was first observed in late season 1997 in San Joaquin Valley populations with LC50s ranging from 16 to 22 microg (AI)/liter(-1) compared with IC50s of 1 to 3 mg (AI)/liter(-1) in Imperial, Palo Verde Valley and Yuma populations. Whiteflies collected in subsequent years from these and other locations showed an increase in susceptibility to buprofezin. Regional differences in susceptibilities to pyriproxyfen were minimal within the same years. Three years of sampling revealed consistently higher LC50s to pyriproxyfen in populations from Palo Verde Valley, CA, compared with whiteflies from Imperial, San Joaquin Valley or Yuma. As was the case with buprofezin, a decline in LC50s to pyriproxyfen was observed in whiteflies from all locations sampled in 1999. However, no correlation was observed between buprofezin and pyriproxyfen toxicity in any of the strains. The variable toxicities observed to both compounds over a period of 3 yr may be due principally to inherent differences among geographical populations or due to past chemical use which may confer positive or negative cross-resistance to buprofezin or pyriproxyfen.

Action threshold for applying insect growth regulators to tomato for management of irregular ripening caused by Bemisia argentifolii (Homoptera: Aleyrodidae).

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Schuster, D J

2002-04-01

The whitefly Bemisia argentifolii Bellows & Perring is a major pest of tomatoes, causing an irregular ripening disorder characterized externally by incomplete or inhibited reddening of fruit, especially in longitudinal sections, and internally by an increase in the amount of white tissue. Experiments were undertaken during the spring and fall of 1997 and 1998 and the spring of 1999 to develop an action threshold for applying the insect growth regulators (IGRs) buprofezin and pyriproxyfen to manage B. argentifolii and irregular ripening. The IGRs were applied when predetermined thresholds were reached and were compared with a high rate of the systemic insecticide imidacloprid, which was applied at transplanting and provided season-long whitefly control. Only plots treated when the numbers of sessile nymphs (second through fourth instars) reached five per 10 leaflets consistently had both external and internal irregular ripening severity ratings similar to the imidacloprid standard. Results were similar for buprofezin and pyriproxyfen even though the modes of action differ. The five nymphs per 10 leaflets threshold lends itself to field scouting because nymphal counts completed in the field using the unaided eye supplemented with a 10x hand lens were linearly and significantly related to counts completed in the laboratory with a dissecting microscope.

Dissipation rate of thiacloprid and its control effect against Bemisia tabaci in greenhouse tomato after soil application.

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Dong, Sa; Qiao, Kang; Wang, Hongyan; Zhu, Yukun; Xia, Xiaoming; Wang, Kaiyun

2014-08-01

Thiacloprid is a chloronicotinyl insecticide that is quite effective against sucking insects. In this study, when thiacloprid was applied at two different rates (normal rate 15 kg ha(-1) , double rate 30 kg ha(-1) ), the systemic distribution and residue of thiacloprid as well as its control effect against whitefly (Bemisia tabaci) were investigated in greenhouse tomato after soil application. The results showed that thiacloprid was present in the tomato leaves until day 25, and then its amount was less than 0.005 mg kg(-1) and could not be detected. Thiacloprid residue in the tomato stems basically remained at a stable low level throughout the experimental period. Thiacloprid in soil had half-lives of 11.8 and 12.5 days for the normal treatment and the double treatment respectively. The control efficiency of whiteflies was about 90% from day 1 to day 10. This was followed by a slow decline, but efficiency was still higher than 50% until day 21. In addition, no significant differences were noted in the control effect of thiacloprid on whiteflies between the two different rates. Soil application of thiacloprid at the normal rate can effectively control whiteflies, with high efficiency and long persistence. © 2013 Society of Chemical Industry.

Intra- and interspecific competition between western flower thrips and sweetpotato whitefly.

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Wu, Qing-Jun; Hou, Wen-Jie; Li, Fei; Xu, Bao-Yun; Xie, Wen; Wang, Shao-Li; Zhang, You-Jun

2014-01-01

The western flower thrips, Frankliniella occidentalis (Pergande), and the sweetpotato whitefly, Bemisia tabaci (Gennadius), are both invasive insect pests and are present in most of the same agricultural crops without a clear dominance of either species. Here, intra- and interspecific competition in B. tabaci and F. occidentalis was determined under controlled experiments. The results showed that intraspecific competition was distinct in F. occidentalis and that the co-occurrence of B. tabaci had a strong effect on F. occidentalis, resulting in a decrease in oviposition. Significant intraspecific competition was found in B. tabaci, and the coexistence of F. occidentalis had limited effect on the oviposition of B. tabaci. In a selective host plant preference experiment, both F. occidentalis and B. tabaci preferred eggplants most, followed by cucumbers and tomatoes. On cucumber plants, B. tabaci was predominant, whereas on eggplant and tomato plants, F. occidentalis and B. tabaci exhibited comparative competitive abilities during the initial stage. However, over time, higher numbers of B. tabaci than that of F. occidentalis were found on the two host plants. Our in vitro and potted plant experiments indicate that B. tabaci is competitively superior to F. occidentalis, which might help to explain their differential distribution patterns in China. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Severity of cotton whitefly (bemisia tabaci genn.) population with special reference to abiotic factors

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Zia, K.; Bashir, M.H.; Khan, B.S.; Khan, R.R.; Hafeez, F.

2013-01-01

Bemisia tabaci is serious insect and constantly destabilizing the cotton production. The research was conducted to evaluate cotton cultivars (transgenic and non transgenic) for resistance against whitefly and further correlated with weather factors such as temperature, relative humidity and rainfall, during the cropping seasons 2010 and 2011. However, peak population (6.36 per leaf) was recorded from FH-113 followed FH-167 and FH-114, whereas minimum population was recorded from FH-4243 in transgenic group whereas peak population (5.24 per leaf) was recorded from FH- 941 followed by FH-100 and FH- 901 while minimum population was recorded from FH-207, in non transgenic group of cultivars in the year 2010. The incidence and abundance was much high and reaching towards two folds in the year 2011 but the trend of whitefly varied with peak population (11.03 per leaf) recorded from FH -167 followed by FH- 4243 and FH113 (from transgenic group of cultivars) whereas a peak of 10.77 per leaf population of whitefly, recorded followed by FH-901 and FH-941 (from non transgenic group of cultivars). FH-207 found more resistant from all ten cultivars studied in 2011. Correlation among weather factors and whitefly population showed that rainfall was negatively correlated while temperature and relative humidity were positively correlated with whitefly population. In addition to that situation is becoming worse because of shifting from conventional to more advanced transgenic cultivars that are susceptible and serve as host. Moreover, climatic conditions provide addition favor and helps in population buildup, abundance and incidence. (author)

Assessing Compatibility of Isaria fumosorosea and Buprofezin for Mitigation of Aleurodicus rugioperculatus (Hemiptera: Aleyrodidae): An Invasive Pest in the Florida Landscape.

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Kumar, Vivek; Francis, Antonio; Avery, Pasco B; McKenzie, Cindy L; Osborne, Lance S

2018-05-28

Rugose spiraling whitefly (RSW), Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae) is a new invasive whitefly pest in the Florida landscape, known to feed on a wide range of plants including palms, woody ornamentals, shrubs, and fruits. With the objective to find an alternative to neonicotinoid insecticides, and develop an ecofriendly management program for RSW, in the current study we evaluated the efficacy of a biopesticide containing the entomopathogenic fungi, Isaria fumosorosea Wize (Hypocreales: Clavicipitaceae), and an insect growth regulator buprofezin applied alone and in combination under laboratory and field conditions. Before assessing the two products, their compatibility was studied at six different concentrations of buprofezin. No significant inhibitive effect of buprofezin was observed on I. fumosorosea spore germination, and the average linear growth of the colony measured 14 d postinoculation. Under laboratory conditions, I. fumosorosea treatments (alone or mixed with buprofezin) provided higher RSW mortality than buprofezin alone. However, in both outdoor cage studies, the efficacy of buprofezin treatments (alone or mixed with I. fumosorosea) was higher than I. fumosorosea alone. A significant reduction in RSW population was reported for more than 5 wk in buprofezin alone and more than 7 wk in the combination treatments. In fall of 2014 and summer of 2015, the mean whitefly mortality observed during the 10-wk assessment period was 52.4 and 42.1% for I. fumosorosea, 79.6 and 79.0% for buprofezin, and 87.6 and 84.3% in mixed treatments, respectively. Results suggest that buprofezin can offer an effective alternate in the battle against invasive whiteflies such as RSW in Florida ecosystems, either as a stand-alone strategy or in an integrated approach.

Onion thrips (Thrips tabaci (Thysanoptera: Thripidae)) in cabbage on Prince Edward Island: observations on planting date and variety choice.

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Blatt, Suzanne; Ryan, Andrew; Adams, Shelley; Driscoll, Joanne

2015-01-01

Onion thrips (Thrips tabaci Lindeman (Thysanoptera: Thripidae)) can be a pest in organic onion production on Prince Edward Island. This study was to examine the effect of planting time and variety on infestation levels and damage by onion thrips on cabbage (Brassicae oleracea capitala (L.)). A field site was planted with 2 main and 8 lesser varieties of cabbage over 4 planting dates. Some varieties were short season and harvested on July 31 with longer season varieties harvested on September 2. Blue sticky traps were used to capture thrips migrating into the field site from July 22-September 2. Traps were counted weekly and cabbage heads within the field site were visually surveyed for thrips. At harvest, heads were weighed and measured, thrips damage was assessed then the head was dissected and thrips counted on the first four layers of the head. Thrips exhibited a preference for Lennox over Bronco throughout the season although thrips populations were not high enough to effect economic damage in 2014. Planting date influenced cabbage head weight and size with later plantings yielding the largest heads. Use of planting date and variety to avoid thrips populations is discussed.

Enterobacter tabaci sp. nov., a novel member of the genus Enterobacter isolated from a tobacco stem.

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Duan, Yan-Qing; Zhou, Xing-Kui; Di-Yan, Li; Li, Qing-Qing; Dang, Li-Zhi; Zhang, Yong-Guang; Qiu, Li-Hong; Nimaichand, Salam; Li, Wen-Jun

2015-11-01

A Gram-stain negative, motile, rod-shaped bacterium, designated strain YIM Hb-3(T), was isolated from the stem of a tobacco plant. The strain was observed to form convex, circular and yellow-colored colonies. The predominant respiratory quinone was identified as Q-8. The major fatty acids (>5%) detected were C(16:1)ω7c and/or C(16:1)ω6c (summed feature 3), C(16:0), C(17:0)cyclo, C(18:1)ω7c and/or C(18:1)ω6c (summed feature 8), C(14:0)3-OH and/or iso-C(16:1)I (summed feature 2), C(14:0) and C(12:0). The genomic DNA G+C content was determined to be 54.8 mol%. Phylogenetic trees based on 16S rRNA gene sequences and multilocus sequence analysis showed that strain YIM Hb-3(T) had the closest phylogenetic relationship with Enterobacter mori LMG 25706(T). DNA-DNA relatedness value between strain YIM Hb-3(T) and E. mori LMG 25706(T) was 46.9 ± 3.8%. On the basis of phenotypic and chemotaxonomic data, phylogenetic analysis, and DNA-DNA relatedness value, strain YIM Hb-3(T) is considered to represent a novel species of the genus Enterobacter, for which the name Enterobacter tabaci sp. nov. is proposed. The type strain is YIM Hb-3(T) (=KACC 17832(T) =KCTC 42694(T)).

Tomato severe rugose virus (ToSRV) e Tomato chlorosis virus (ToCV): relações com a Bemisia tabaci biótipo B e eficiência de um inseticida no controle da transmissão do ToSRV

OpenAIRE

Debora Maria Sansini Freitas

2012-01-01

A cultura do tomateiro (Solanum lycopersicum L.) é importante mundialmente devido ao alto consumo de seus frutos. Nos últimos anos surgiram nesta cultura no Brasil alguns vírus emergentes com altas taxas de disseminação, como begomovírus e crinivírus, transmitidos pela Bemisia tabaci biótipo B, que podem causar danos à produção do tomateiro. A espécie de begomovírus atualmente mais encontrada no Brasil, em plantios de tomateiro, é o Tomato severe rugose virus (ToSRV). De 2002 a 2004, pesquisa...

EFICIÊNCIA DO CONTROLE QUÍMICO SOBRE A MOSCA BRANCA Bemisia tabaci biótipo B (HEMIPTERA: ALEYRODIDAE EM MELOEIRO

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Antônio Lindemberg Martins Mesquita

2007-01-01

efficient to control eggs, nymphs and adults of the whitefly, while the insect growth regulators buprofezin and pyriproxyfen did not control eggs and adults, but they controled nymphs, being pyriproxyfen more efficient than buprofezin.

Management of white flies (Bemisia tabaci) in tomato with a combination of plastic mulch and insecticides in Costa Rica

International Nuclear Information System (INIS)

Cubillo, D.; Hilje, L.; Valverde, B.E.; Carazo, E.

1999-01-01

A combination of silver plastic soil cover and application of endosulfan or imidacloprid for the control of whiteflies (Bemisia tabaci) in tomato was compared to farmer's practice in Guayabo, Turrialba, Costa Rica. None of the treatments affected the whitefly infestation which was very low, the highest value being 2.25 adults/10 plants. Viral disease incidence amounted only 2.4 to 4.4% by the end of the crop season, the highest incidence levels were consistently observed in control treatments. Such negligible incidence values precluded evaluation of disease severity. Fruit number or weight and total yield were not affected by the treatments. No detectable residues of endosulfan or its metabolites were present in either foliage or fruit tissues. In soil samples, minute amounts of α- and β-endosulfan were found as well as endosulfan sulphate, the most important metabolite. Insecticide residues were always higher in the plots that were treated twice compared to those that were sprayed only once with endosulfan. No endosulfan or metabolites were detected in control plots. The lack of residues in plant tissues and the minute amounts found in soils indicate that endosulfan can be used as part as an integrated program for whitefly control in tomato. (author)

Virus infection of a weed increases vector attraction to and vector fitness on the weed.

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Chen, Gong; Pan, Huipeng; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Fang, Yong; Shi, Xiaobin; Zhang, Youjun

2013-01-01

Weeds are important in the ecology of field crops, and when crops are harvested, weeds often become the main hosts for plant viruses and their insect vectors. Few studies, however, have examined the relationships between plant viruses, vectors, and weeds. Here, we investigated how infection of the weed Datura stramonium L. by tomato yellow leaf curl virus (TYLCV) affects the host preference and performance of the TYLCV vector, Bemisia tabaci (Gennadius) Q. The results of a choice experiment indicated that B. tabaci Q preferentially settled and oviposited on TYLCV-infected plants rather than on healthy plants. In addition, B. tabaci Q performed better on TYLCV-infected plants than on healthy plants. These results demonstrate that TYLCV is indirectly mutualistic to B. tabaci Q. The mutually beneficial interaction between TYLCV and B. tabaci Q may help explain the concurrent outbreaks of TYLCV and B. tabaci Q in China.

Effect of insecticides on mealybug destroyer (Coleoptera: Coccinellidae) and parasitoid Leptomastix dactylopii (Hymenoptera: Encyrtidae), natural enemies of citrus mealybug (Homoptera: Pseudococcidae).

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Cloyd, Raymond A; Dickinson, Amy

2006-10-01

In this study, we measured, under laboratory conditions, the direct and indirect effects of insecticides on mealybug destroyer, Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae), and parasitoid Leptomastix dactylopii Howard (Hymenoptera: Encyrtidae), natural enemies of citrus mealybug, Planococcus citri (Risso) (Homoptera: Pseudococcidae). The adult stages of both natural enemies were exposed to sprays of the insecticides buprofezin, pyriproxyfen, flonicamid, acetamiprid, dinotefuran, and clothianidin at label-recommended rates to assess direct mortality after 24, 48, and 72 h, respectively. The effects of the insecticides on L. dactylopii parasitization rate and percentage of parasitoid emergence also were monitored using the label and 4x the recommended label rate. Dinotefuran was extremely detrimental to the adult parasitoid at the label rate with 100% mortality after 24 h. Buprofezin, pyriproxyfen, and flonicamid were not harmful to L. dactylopii when applied at the label rate. At 4x the recommended label rate, dinotefuran, acetamiprid, and clothianidin were all harmful to the parasitoid with 100% mortality 72 h after application. Both buprofezin and flonicamid were not toxic to L. dactylopii with 100% adult survival after 72 h. Pyriproxyfen and flonicamid, at both the label and 4x the recommended label rate, did not negatively affect L. dactylopii parasitization rate or percentage of parasitoid emergence. Acetamiprid, dinotefuran, and clothianidin were toxic to C. montrouzieri adults with 100% mortality after 48 h, whereas buprofezin, pyriproxyfen, and flonicamid demonstrated minimal (10-20% mortality after 48 h) harmful effects to the predator. Based on the results from our study, the indirect effects of the insect growth regulator (IGR) buprofezin were not decisive; however, the IGR pyriproxyfen and the insecticide flonicamid were not directly or indirectly harmful to the predator C. montrouzieri and parastioid L. dactylopii, indicating that

Rapid genetic turnover in populations of the insect pest Bemisia tabaci Middle East: Asia Minor 1 in an agricultural landscape.

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Dinsdale, A; Schellhorn, N A; De Barro, P; Buckley, Y M; Riginos, C

2012-10-01

Organisms differ greatly in dispersal ability, and landscapes differ in amenability to an organism's movement. Thus, landscape structure and heterogeneity can affect genetic composition of populations. While many agricultural pests are known for their ability to disperse rapidly, it is unclear how fast and over what spatial scale insect pests might respond to the temporally dynamic agricultural landscapes they inhabit. We used population genetic analyses of a severe crop pest, a member of the Bemisia tabaci (Hemiptera: Sternorrhyncha: Aleyrodoidea: Aleyrodidea) cryptic species complex known as Middle East-Asia Minor 1 (commonly known as biotype B), to estimate spatial and temporal genetic diversity over four months of the 2006-2007 summer growing season. We examined 559 individuals from eight sites, which were scored for eight microsatellite loci. Temporal genetic structure greatly exceeded spatial structure. There was significant temporal change in local genetic composition from the beginning to the end of the season accompanied by heterozygote deficits and inbreeding. This temporal structure suggests entire cohorts of pests can occupy a large and variable agricultural landscape but are rapidly replaced. These rapid genetic fluctuations reinforce the concept that agricultural landscapes are dynamic mosaics in time and space and may contribute to better decisions for pest and insecticide resistance management.

Evaluation of Insecticides and Agril Polyester Cover against Whitefly (Bemisia Tabaci Gennadius in Tomato Crops

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K.M. Azam

1996-01-01

Full Text Available Field experiments were conducted on tomato crops over a two year period to evaluate the efficacy of six insecticides, viz., triazophos, phosphamidon, dimethoate, buprofezin and Aflix (endosulfan + dimethoate each at 0.05% and Repelin (plant insecticide at 1% concentration along With a cultural treatment by covering the plants with Agril (a polyester material for the control of whitefly, Bemisia tabaci. The insecticides were applied eight times at weekly interval immediately after transplantation. The whitefly eggs,  nymphal population counts and the per cent incidence of tomato leaf curl virus (TLCV were recorded every week for eight weeks in all the treatments including untreated control. The incidence of whitefly was more severe in the second year (i.e, 1992-93 as compared to the previous season. Among the various treatments, the Agril cover, a newly introduced cultural practice, recorded the least incidence of whitefly and of TLCV. The average of counts of eggs were 0.0 and 5.47 and of nymphs 0.54 and 0.58 per 10 leaflets and TLCV were 4.32% and 4.76% in Agril cover treatment during the first and second year, respectively. Among the insecticides tested only Aflix recorded less incidence of the pest, being 3.46 and 30.4 eggs per 10 leaflets and 0.94 and 5.34 nymphs per 10 leaflets during the two years of study, respectively. The other treatments were less effective in reducing pest and disease incidence. The crop under Agril-cover recorded the maximum yield of 34.57 and 26.15 t/ha of tomatoes as compared to 16.48 and 10.82 t/ha in control during the first and second year, respectively.

Low levels of mitochondrial DNA and symbiont diversity in the worldwide agricultural pest, the greenhouse whitefly Trialeurodes vaporariorum (Hemiptera: Aleyrodidae).

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Kapantaidaki, Despoina E; Ovčarenko, Irina; Fytrou, Natasa; Knott, K Emily; Bourtzis, Kostas; Tsagkarakou, Anastasia

2015-01-01

Trialeurodes vaporariorum, the greenhouse whitefly, is a cosmopolitan agricultural pest. Little is known about the genetic diversity of T. vaporariorum and the bacterial symbionts associated with this species. Here, we undertook a large phylogeographic study by investigating both the mitochondrial (mt) diversity and the infection status of 38 T. vaporariorum collections from 18 countries around the world. Genetic diversity of T. vaporariorum was studied by analyzing sequence data from the mt cytochrome oxidase I, cytochrome b, and NADH dehydrogenase subunit 5 genes. Maximum-likelihood (ML) phylogeny reconstruction delineated 2 clades characterized by limited sequence divergence: one clade comprised samples only from the Northern hemisphere whereas the other comprised samples from a broader geographical range. The presence of secondary symbionts was determined by PCR using primers specific for Hamiltonella, Rickettsia, Arsenophonus, Cardinium, Wolbachia, and Fritschea. Most individuals examined harbored at least one secondary endosymbiont, and Arsenophonus was detected in almost all male and female individuals. Wolbachia was present at a much lower frequency, and Cardinium was detected in only a few individuals from Greece. Rickettsia, Hamiltonella, and Fritschea were not found. Additionally, we set out to further analyze Arsenophonus diversity by multilocus sequence typing analysis; however, the Arsenophonus sequences did not exhibit any polymorphism. Our results revealed remarkably low diversity in both mtDNA and symbionts in this worldwide agricultural pest, contrasting sharply with that of the ecologically similar Bemisia tabaci. © The American Genetic Association 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Genetic networking of the Bemisia tabaci cryptic species complex reveals pattern of biological invasions.

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Paul De Barro

Full Text Available BACKGROUND: A challenge within the context of cryptic species is the delimitation of individual species within the complex. Statistical parsimony network analytics offers the opportunity to explore limits in situations where there are insufficient species-specific morphological characters to separate taxa. The results also enable us to explore the spread in taxa that have invaded globally. METHODOLOGY/PRINCIPAL FINDINGS: Using a 657 bp portion of mitochondrial cytochrome oxidase 1 from 352 unique haplotypes belonging to the Bemisia tabaci cryptic species complex, the analysis revealed 28 networks plus 7 unconnected individual haplotypes. Of the networks, 24 corresponded to the putative species identified using the rule set devised by Dinsdale et al. (2010. Only two species proposed in Dinsdale et al. (2010 departed substantially from the structure suggested by the analysis. The analysis of the two invasive members of the complex, Mediterranean (MED and Middle East - Asia Minor 1 (MEAM1, showed that in both cases only a small number of haplotypes represent the majority that have spread beyond the home range; one MEAM1 and three MED haplotypes account for >80% of the GenBank records. Israel is a possible source of the globally invasive MEAM1 whereas MED has two possible sources. The first is the eastern Mediterranean which has invaded only the USA, primarily Florida and to a lesser extent California. The second are western Mediterranean haplotypes that have spread to the USA, Asia and South America. The structure for MED supports two home range distributions, a Sub-Saharan range and a Mediterranean range. The MEAM1 network supports the Middle East - Asia Minor region. CONCLUSION/SIGNIFICANCE: The network analyses show a high level of congruence with the species identified in a previous phylogenetic analysis. The analysis of the two globally invasive members of the complex support the view that global invasion often involve very small portions of

High-level of resistance to spinosad, emamectin benzoate and carbosulfan in populations of Thrips tabaci collected in Israel.

Science.gov (United States)

Lebedev, Galina; Abo-Moch, Fauzi; Gafni, Guy; Ben-Yakir, David; Ghanim, Murad

2013-02-01

The onion thrips, Thrips tabaci Lindeman, is a major pest of several crop plants in the genus Allium, such as onions, garlic and chives. In Israel, these crops are grown in open fields and in protected housing. This thrips is usually controlled by the application of chemical insecticides. In recent years, spinosad, emamectin benzoate and carbosulfan have been the major insecticides used for the control of the onion thrips. In the last 4 years, growers of chives and green onion from several regions of Israel have reported a significant decrease in the efficacy of insecticides used to control the onion thrips. The susceptibility of 14 populations of the onion thrips, collected mainly from chives between the years 2007 and 2011, to spinosad, emamectin benzoate and carbosulfan was tested using a laboratory bioassay. The majority of the populations showed significant levels of resistance to at least one of the insecticides. LC(50) values calculated for two of the studied populations showed that the resistance factor for spinosad compared with the susceptible population is 21 393, for carbosulfan 54 and for emamectin benzoate 36. Only two populations, collected from organic farms, were susceptible to the insecticides tested. This is the first report of a high resistance level to spinosad, the major insecticide used to control the onion thrips. Resistance cases to spinosad were associated with failures to control the pest. Populations resistant to spinosad also had partial or complete resistance to other insecticides used for controlling the onion thrips. Copyright © 2012 Society of Chemical Industry.

Feeding of Whitefly on Tobacco Decreases Aphid Performance via Increased Salicylate Signaling.

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Haipeng Zhao

Full Text Available The feeding of Bemisia tabaci nymphs trigger the SA pathway in some plant species. A previous study showed that B. tabaci nymphs induced defense against aphids (Myzus persicae in tobacco. However, the mechanism underlying this defense response is not well understood.Here, the effect of activating the SA signaling pathway in tobacco plants through B. tabaci nymph infestation on subsequent M. persicae colonization is investigated. Performance assays showed that B. tabaci nymphs pre-infestation significantly reduced M. persicae survival and fecundity systemically in wild-type (WT but not salicylate-deficient (NahG plants compared with respective control. However, pre-infestation had no obvious local effects on subsequent M. persicae in either WT or NahG tobacco. SA quantification results indicated that the highest accumulation of SA was induced by B. tabaci nymphs in WT plants after 15 days of infestation. These levels were 8.45- and 6.14-fold higher in the local and systemic leaves, respectively, than in controls. Meanwhile, no significant changes of SA levels were detected in NahG plants. Further, biochemical analysis of defense enzymes polyphenol oxidase (PPO, peroxidase (POD, β-1,3-glucanase, and chitinase demonstrated that B. tabaci nymph infestation increased these enzymes' activity locally and systemically in WT plants, and there was more chitinase and β-1, 3-glucanase activity systemically than locally, which was opposite to the changing trends of PPO. However, B. tabaci nymph infestation caused no obvious increase in enzyme activity in any NahG plants except POD.In conclusion, these results underscore the important role that induction of the SA signaling pathway by B. tabaci nymphs plays in defeating aphids. It also indicates that the activity of β-1, 3-glucanase and chitinase may be positively correlated with resistance to aphids.

New cost-effective bioconversion process of palm kernel cake into bioinsecticides based on Beauveria bassiana and Isaria javanica.

Science.gov (United States)

do Nascimento Silva, Jaqueline; Mascarin, Gabriel Moura; Dos Santos Gomes, Isabel Cristina; Tinôco, Ricardo Salles; Quintela, Eliane Dias; Dos Reis Castilho, Leda; Freire, Denise Maria Guimarães

2018-03-01

The present study aimed to add value to palm oil by-products as substrates to efficiently produce conidia of Beauveria bassiana and Isaria javanica (Hypocreales: Cordycipitaceae) for biological control of the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae), through a solid-state fermentation process using palm kernel cake and palm fiber as nutrient source and solid matrix, respectively. The optimum culture conditions yielded high concentrations of viable conidia after air-drying, when the fungi were grown on palm kernel cake (B. bassiana 7.65 × 10 9 and I. javanica 2.91 × 10 9  conidia g -1 dry substrate) after 6 days under optimal growth conditions set to 60% substrate moisture and 32 °C. Both fungal strains exhibited high efficacy against third-instar whitefly nymphs, inducing mortality up to 62.9 and 56.6% by B. bassiana and I. javanica, respectively, assessed after 9 days post-application in a screenhouse. Furthermore, we noted that insect mortality was strongly correlated with high atmospheric moisture, while B. bassiana appeared to require shorter accumulative hours under high moisture to kill whitefly nymphs compared to I. javanica. Our results underpin a feasible and cost-effective mass production method for aerial conidia, using palm kernel as the main substrate in order to produce efficacious fungal bioinsecticides against an invasive whitefly species in Brazil. Finally, our fermentation process may offer a sustainable and cost-effective means to produce eco-friendly mycoinsecticides, using an abundant agro-industrial by-product from Brazil that will ultimately assist in the integrated management of agricultural insect pests.

A possible role for acetylated intermediates in diaminopimelate and tabtoxinine-beta-lactam biosynthesis in Pseudomonas syringae pv. tabaci BR2.024.

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Liu, L; Shaw, P D

1997-01-01

The deduced product of an open reading frame (ORF3) located in the tabtoxinine-beta-lactam (T beta L) biosynthetic region of Pseudomonas syringae pv. tabaci BR2.024 (BR2.024) has significant sequence homology to the dapD products of other bacteria. dapD encodes L-2,3,4,5-tetrahydrodipicolinate succinyl coenzyme A succinyltransferase (THDPA-ST), an enzyme in the diaminopimelate (DAP) and lysine biosynthetic pathway. Complementation studies, in vitro transcription-translation experiments, and enzymatic assays indicated that ORF3 encodes a product with THDPA-ST activity in Escherichia coli dapD mutant beta 274. However, a BR2.024 mutant with an insert in ORF3 was prototrophic, and only basal THDPA-ST activity was detected in extracts of both parent and mutant. This finding suggested that ORF3 was not required for DAP biosynthesis and that it did not encode a product with THDPA-ST activity. The results of enzymatic studies, indicating that BR2.024 uses acetylated intermediates for DAP biosynthesis, are consistent with the hypothesis that BR2.024 does not need THDPA-ST for DAP biosynthesis. The ORF3 mutant produced reduced levels of tabtoxin, indicating that ORF3 may have a role in T beta L biosynthesis. We have named the gene tabB and have proposed a possible function for the gene product. PMID:9294453

Characterization of dapB, a gene required by Pseudomonas syringae pv. tabaci BR2.024 for lysine and tabtoxinine-beta-lactam biosynthesis.

Science.gov (United States)

Liu, L; Shaw, P D

1997-01-01

The dapB gene, which encodes L-2,3-dihydrodipicolinate reductase, the second enzyme of the lysine branch of the aspartic amino acid family, was cloned and sequenced from a tabtoxin-producing bacterium, Pseudomonas syringae pv. tabaci BR2.024. The deduced amino acid sequence shared 60 to 90% identity to known dapB gene products from gram-negative bacteria and 19 to 21% identity to the dapB products from gram-positive bacteria. The consensus sequence for the NAD(P)H binding site [(V/I)(A/G)(V/I)XGXXGXXG)] and the proposed substrate binding site (HHRHK) were conserved in the polypeptide. A BR2.024 dapB mutant is a diaminopimelate auxotroph and tabtoxin negative. The addition of a mixture of L-,L-, D,D-, and meso-diaminopimelate to defined media restored growth but not tabtoxin production. Cloned DNA fragments containing the parental dapB gene restored the ability to grow in defined media and tabtoxin production to the dapB mutant. These results indicate that the dapB gene is required for both lysine and tabtoxin biosynthesis, thus providing the first genetic evidence that the biosynthesis of tabtoxin proceeds in part along the lysine biosynthetic pathway. These data also suggest that L-2,3,4,5-tetrahydrodipicolinate is a common intermediate for both lysine and tabtoxin biosynthesis. PMID:8990304

Pesticide-mediated interspecific competition between local and invasive thrips pests

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Zhao, Xueyin; Reitz, Stuart R.; Yuan, Huiguo; Lei, Zhongren; Paini, Dean Ronald; Gao, Yulin

2017-01-01

Competitive interactions between species can be mitigated or even reversed in the presence of anthropogenic influences. The thrips species Frankliniella occidentalis and Thrips tabaci are highly invasive and damaging agricultural pests throughout the world. Where the species co-occur, one species tends to eventually predominate over the other. Avermectin and beta-cypermethrin are commonly used insecticides to manage thrips in China, and laboratory bioassays demonstrated that F. occidentalis is significantly less susceptible than T. tabaci to these insecticides. In laboratory cage trials in which both species were exposed to insecticide treated cabbage plants, F. occidentalis became the predominant species. In contrast, T. tabaci completely displaced F. occidentalis on plants that were not treated with insecticides. In field trials, the species co-existed on cabbage before insecticide treatments began, but with T. tabaci being the predominant species. Following application of avermectin or beta-cypermethrin, F. occidentalis became the predominant species, while in plots not treated with insecticides, T. tabaci remained the predominant species. These results indicate that T. tabaci is an intrinsically superior competitor to F. occidentalis, but its competitive advantage can be counteracted through differential susceptibilities of the species to insecticides. These results further demonstrate the importance of external factors, such as insecticide applications, in mediating the outcome of interspecific interactions and produce rapid unanticipated shifts in the demographics of pest complexes. PMID:28084404

Pesticide-mediated interspecific competition between local and invasive thrips pests.

Science.gov (United States)

Zhao, Xueyin; Reitz, Stuart R; Yuan, Huiguo; Lei, Zhongren; Paini, Dean Ronald; Gao, Yulin

2017-01-13

Competitive interactions between species can be mitigated or even reversed in the presence of anthropogenic influences. The thrips species Frankliniella occidentalis and Thrips tabaci are highly invasive and damaging agricultural pests throughout the world. Where the species co-occur, one species tends to eventually predominate over the other. Avermectin and beta-cypermethrin are commonly used insecticides to manage thrips in China, and laboratory bioassays demonstrated that F. occidentalis is significantly less susceptible than T. tabaci to these insecticides. In laboratory cage trials in which both species were exposed to insecticide treated cabbage plants, F. occidentalis became the predominant species. In contrast, T. tabaci completely displaced F. occidentalis on plants that were not treated with insecticides. In field trials, the species co-existed on cabbage before insecticide treatments began, but with T. tabaci being the predominant species. Following application of avermectin or beta-cypermethrin, F. occidentalis became the predominant species, while in plots not treated with insecticides, T. tabaci remained the predominant species. These results indicate that T. tabaci is an intrinsically superior competitor to F. occidentalis, but its competitive advantage can be counteracted through differential susceptibilities of the species to insecticides. These results further demonstrate the importance of external factors, such as insecticide applications, in mediating the outcome of interspecific interactions and produce rapid unanticipated shifts in the demographics of pest complexes.

Intensidade de ataque de tripes, de alternaria e da queima-das-pontas em cultivares de cebola Intensity of attacks of thrips, purple blotch and gray mold on onion cultivars

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Germano L.D. Leite

2004-03-01

Full Text Available Avaliou-se a intensidade de ataque de Thrips tabaci Lind., a incidência de Alternaria porri (Ellis e Botrytis squamosa J.C. Walker em nove cultivares de cebola [Aurora, Primavera, CNPH 6400, Crioula Alto-Vale, Vale-Ouro (IPA 11, Franciscana (IPA-16, Piraouro, Conquista e Serrana], num experimento no delineamento em blocos casualizados com cinco repetições. Foram feitas avaliações semanais, do transplantio até a colheita, em dez plantas/parcela do número de T. tabaci presente na bainha das folhas bem como da percentagem de área foliar danificada pelo mesmo a partir da primeira folha expandida e também da presença ou da ausência de lesões causadas por A. porri e B. squamosa. A cv. Franciscana mostrou-se mais resistente em relação às demais ao ataque de T. tabaci. Não houve diferença significativa de plantas afetadas por A. porri e B. squamosa. T. tabaci e A. porri foram ambos afetados positiva e negativamente pela temperatura e pela umidade relativa do ambiente, respectivamente.The intensity of attack of T. tabaci and incidence of Alternaria porri (Ellis Cif and Botrytis squamosa J.C. Walker in nine onion cultivars [Aurora, Primavera, CNPH 6400, Crioula Alto-Vale, Vale-Ouro (IPA 11, Franciscana (IPA-16, Piraouro, Conquista and Serrana] was evaluated, in an experiment in randomized blocks design, with five replications. Weekly evaluations were done from the transplanting until harvesting date, in ten plants/parcel of the number of T. tabaci on the leaves, the percentage of damaged foliar area from the first expanded leaf up and the presence or absence of injuries caused by A. porri and B. squamosa. The cv. Franciscana was more resistant to the attack of T. tabaci in comparison to the other onion cultivars. There was no significant difference between cvs for A. porri and Botrytis squamosa resistance. T. tabaci and A. porri were influenced positively and negatively by temperature and relative humidity, respectively.

A Molecular Phylogeny of Hemiptera Inferred from Mitochondrial Genome Sequences

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Song, Nan; Liang, Ai-Ping; Bu, Cui-Ping

2012-01-01

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. PMID:23144967

A molecular phylogeny of Hemiptera inferred from mitochondrial genome sequences.

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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.

Statement on the dossier for a derogation request of the US authorities concerning cold-treated strawberry plants intended for planting

DEFF Research Database (Denmark)

Baker, R.; Candresse, T.; Dormannsné Simon, E.

2009-01-01

Following a request from the European Commission, the EFSA Panel on Plant Health examined the report “Evaluation of Strawberry Nursery Plant Cold Treatments on Survival of the Whitefly, Bemisia tabaci”, submitted to the European Commission by the United States Department of Agriculture (USDA...... the effectiveness of the cold treatment proposed for the elimination of B. tabaci from strawberry plant consignments prepared for shipment to the EU. In addition, the Panel conducted a preliminary review of the available literature on viruses of strawberry and concluded that no B. tabaci-transmitted viruses...... are currently known to infect strawberry and that no viruses of Fragaria listed in European Council Directive 2000/29/EC are known to be transmitted by B. tabaci. However, adult whiteflies of B. tabaci on strawberry consignments can carry plant viruses irrespective of whether strawberry is a host plant...

Analysis of the populations genetic variability of Tagosodes orizicolus (Homoptera: Delphacidae), virus vector of the rice white leaf

International Nuclear Information System (INIS)

Hernandez Alfaro, Myriam

2006-01-01

Tagosodes orizicolus (Homoptera: Delphacidae), is a monophagous insect of the rice and virus vector of the white leaf (RHBV). It is distributed in America Central, El Caribe, part of the America del Sur and in Costa Rica it is in all the producing zones of rice. The genetic variability was analyzed by means of RAPD-PCR of individuals from three populations of Costa Rica: Parrita, Guanacaste (Liberia) y San Carlos (Santa Clara), that they are found separated geographically. The technique consisted of amplifying regions at random of the genome of these insects utilizing five primers. A total of 72 polymorphic bands were obtained, that upon being analyzed statistically by means of the multivariate analysis program of numerical taxonomy could show a clear genetic distancing among said populations. The genetic distance observed in the molecular analysis can be explained for the climatic and/or geographical isolation of the populations or by the incident of Wolbachia, riquettsia that induces cytoplasmic sterility in insects. These symbionts are transmitted of generation in generation, of the mother to their offspring and they cause reproductive alterations as cytoplasmic incompatibility, parthenogenesis and feminization. The presence of Wolbachia was determined by means of transmission electronic microscopy being observed in the greasy and muscular weave of the abdomen of T. orizicolus. Rickettsias present pleomorphic morphology and form small groups, that are characterized for the presence of electrondense material semidetached to the cell wall with an interior electronlucent. Its size in transverse cuts ranged between 520 nm of length X 470 nm of width. In addition, its presence was detected by means of the amplification by PCR of the genomic DNA of the insects; a specific primer for the DNA ribosomal 16S of Wolbachia was utilized for it. A 86% of insects of the San Carlos population were positive, a 96% was determined for Guanacaste, a 37% for Parrita and a 100% for

Asymmetric consequences of host plant occupation on the competition between the whiteflies Bemisia tabaci cryptic species MEAM1 and Trialeurodes vaporariorum (Hemiptera: Aleyrodidae)

DEFF Research Database (Denmark)

Zhang, Gui-Fen; Lövei, Gabor L; Hu, Man

2014-01-01

. RESULTS: Resource preoccupied by T. vaporariorum had mostly negative effects on the life history parameters of later-arriving conspecifics. Red-eyed nymph and immature survival of T. vaporariorum decreased when resource was preoccupied by conspecifics, irrespective of the previous occupation scenario...

A study of the super-abundant Bemisia tabaci (Gennadius) species complex (Hemiptera: Aleyrodidae) in cassava Mosaic disease pandemic areas in Tanzania

DEFF Research Database (Denmark)

Tajebe, Lensa Sefera

(Manihot esculenta Crantz) – one of the most important food security crops in sub-Saharan Africa. After the outbreak and spread of a severe form of CMD from Uganda to several East and African countries, the production of cassava has been impaired causing severe yield loss resulting in food shortages....../Hamiltonella/Wolbachia with Arsenophonus or Cardinium. Similarly, double and multiple infections were also common in the IO and EA1 putative species where EA1 individuals commonly harboured Cardinium/Wolbachia with several additional combinations of Rickettsia, Hamiltonella or Arsenophonus. The secondary endosymbiont Fritschea was never...... in the area in general and in understanding this super-abundant pandemicassociated population in particular. Specific studies to assess the presence of other secondary endosymbionts, antibiotic treatments to eliminate certain endosymbionts or to artificially introduce endosymbionts are paramount to fully...

Genetic variation of the greenhouse whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), among populations from Serbia and neighbouring countries, as inferred from COI sequence variability.

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Prijović, M; Skaljac, M; Drobnjaković, T; Zanić, K; Perić, P; Marčić, D; Puizina, J

2014-06-01

The greenhouse whitefly Trialeurodes vaporariorum Westwood, 1856 (Hemiptera: Aleyrodidae) is an invasive and highly polyphagous phloem-feeding pest of vegetables and ornamentals. Trialeurodes vaporariorum causes serious damage due to direct feeding and transmits several important plant viruses. Excessive use of insecticides has resulted in significantly reduced levels of susceptibility of various T. vaporariorum populations. To determine the genetic variability within and among populations of T. vaporariorum from Serbia and to explore their genetic relatedness with other T. vaporariorum populations, we analysed the mitochondrial cytochrome c oxidase I (COI) sequences of 16 populations from Serbia and six neighbouring countries: Montenegro (three populations), Macedonia (one population) and Croatia (two populations), for a total of 198 analysed specimens. A low overall level of sequence divergence and only five variable nucleotides and six haplotypes were found. The most frequent haplotype, H1, was identified in all Serbian populations and in all specimens from distant localities in Croatia and Macedonia. The COI sequence data that was retrieved from GenBank and the data from our study indicated that H1 is the most globally widespread T. vaporariorum haplotype. A lack of spatial genetic structure among the studied T. vaporariorum populations, as well as two demographic tests that we performed (Tajima's D value and Fu's Fs statistics), indicate a recent colonisation event and population growth. Phylogenetic analyses of the COI haplotypes in this study and other T. vaporariorum haplotypes that were retrieved from GenBank were performed using Bayesian inference and median-joining (MJ) network analysis. Two major haplogroups with only a single unique nucleotide difference were found: haplogroup 1 (containing the five Serbian haplotypes and those previously identified in India, China, the Netherlands, the United Kingdom, Morocco, Reunion and the USA) and haplogroup 3

Homoptera, Cicadidae

African Journals Online (AJOL)

1988-10-24

Oct 24, 1988 ... There are also morphological differences between the two taxa which parallel the differences in their .... Female 5 31,0 29,9--32,2 9 26,8 25,3-28,7 -8,11 0,0001. • Student's t test. [. 1mm. A. B. Figure 2 Male genitalia (pygophore and urite). A, P. stridula; ... mainly on trees, all of which were exotics, e.g. Port.

Homoptera: Cicadidae

African Journals Online (AJOL)

1988-10-24

Oct 24, 1988 ... The geographical distributions, habitat preferences, plant associations and seasonal appearance of the platypleurine cicadas occurring on the Natal coastal plain, South Africa, are reported for the first time, and a key to the species is provided. Die geografiese verspreiding, habitatvoorkeur, plantassosiasies ...

Homoptera: Aphididae

African Journals Online (AJOL)

and parasitoids per plant, ladybird beetles per plot, and finally grain yield per plot were recorded. Based on the results of the ANOVA, plant ... is a food, fodder and feed crop belonging to the family Leguminosae (= Fabaceae) ... use of predators, parasitoids and pathogens for pest control, either by introduction from other ...

The ability to manipulate plant glucosinolates and nutrients explains the better performance of Bemisia tabaci Middle East-Asia Minor 1 than Mediterranean on cabbage plants.

Science.gov (United States)

Cui, Hongying; Guo, Litao; Wang, Shaoli; Xie, Wen; Jiao, Xiaoguo; Wu, Qingjun; Zhang, Youjun

2017-08-01

The performance of herbivorous insects is greatly affected by host chemical defenses and nutritional quality. Some herbivores have developed the ability to manipulate plant defenses via signaling pathways. It is currently unclear, however, whether a herbivore can benefit by simultaneously reducing plant defenses and enhancing plant nutritional quality. Here, we show that the better performance of the whitefly Bemisia tabaci Middle East-Asia Minor 1 (MEAM1; formerly the "B" biotype) than Mediterranean (MED; formerly the "Q" biotype) on cabbage is associated with a suppression of glucosinolate (GS) content and an increase in amino acid supply in MEAM1-infested cabbage compared with MED-infested cabbage. MEAM1 had higher survival, higher fecundity, higher intrinsic rate of increase ( r m ), a longer life span, and a shorter developmental time than MED on cabbage plants. Amino acid content was higher in cabbage infested with MEAM1 than MED. Although infestation by either biotype decreased the levels of total GS, aliphatic GS, glucoiberin, sinigrin, glucobrassicin, and 4OH-glucobrassicin, and the expression of related genes in cabbage, MED infestation increased the levels of 4ME-glucobrassicin, neoglucobrassicin, progoitrin, and glucoraphanin. The GS content and expression of GS-related genes were higher in cabbage infested with MED than with MEAM1. Our results suggest that MEAM1 performs better than MED on cabbage by manipulating host defenses and nutritional quality.

Co-infection and localization of secondary symbionts in two whitefly species

Science.gov (United States)

2010-01-01

Background Whiteflies are cosmopolitan phloem-feeding pests that cause serious damage to many crops worldwide due to direct feeding and vectoring of many plant viruses. The sweetpotato whitefly Bemisia tabaci (Gennadius) and the greenhouse whitefly Trialeurodes vaporariorum (Westwood) are two of the most widespread and damaging whitefly species. To complete their unbalanced diet, whiteflies harbor the obligatory bacterium Portiera aleyrodidarum. B. tabaci further harbors a diverse array of secondary symbionts, including Hamiltonella, Arsenophonus, Cardinium, Wolbachia, Rickettsia and Fritschea. T. vaporariorum is only known to harbor P. aleyrodidarum and Arsenophonus. We conducted a study to survey the distribution of whitefly species in Croatia, their infection status by secondary symbionts, and the spatial distribution of these symbionts in the developmental stages of the two whitefly species. Results T. vaporariorum was found to be the predominant whitefly species across Croatia, while only the Q biotype of B. tabaci was found across the coastal part of the country. Arsenophonus and Hamiltonella were detected in collected T. vaporariorum populations, however, not all populations harbored both symbionts, and both symbionts showed 100% infection rate in some of the populations. Only the Q biotype of B. tabaci was found in the populations tested and they harbored Hamiltonella, Rickettsia, Wolbachia and Cardinium, while Arsenophonus and Fritschea were not detected in any B. tabaci populations. None of the detected symbionts appeared in all populations tested, and multiple infections were detected in some of the populations. All endosymbionts tested were localized inside the bacteriocyte in both species, but only Rickettsia and Cardinium in B. tabaci showed additional localization outside the bacteriocyte. Conclusions Our study revealed unique co-infection patterns by secondary symbionts in B. tabaci and T. vaporariorum. Co-sharing of the bacteriocyte by the primary

Presence of Native Prey Does Not Divert Predation on Exotic Pests by Harmonia axyridis in Its Indigenous Range

Science.gov (United States)

Zhang, Gui Fen; Lövei, Gábor L; Wu, Xia; Wan, Fang Hao

2016-01-01

In China, two invasive pests, Bemisia tabaci MEAM1 (Gennadius) and Frankliniella occidentalis (Pergande), often co-occur with the native pest, Aphis gossypii (Glover), on plants of Malvaceae and Cucurbitaceae. All three are preyed on by the native ladybird, Harmonia axyridis (Pallas); however, the native predator might be expected to prefer native prey to the exotic ones due to a shared evolutionary past. In order to clarify whether the presence of native prey affected the consumption of these two invasive species by the native predator, field-cage experiments were conducted. A duplex qPCR was used to simultaneously detect both non-native pests within the gut of the predator. H. axyridis readily accepted both invasive prey species, but preferred B. tabaci. With all three prey species available, H. axyridis consumption of B. tabaci was 39.3±2.2% greater than consumption of F. occidentalis. The presence of A. gossypii reduced (by 59.9% on B. tabaci, and by 60.6% on F. occidentalis), but did not stop predation on the two exotic prey when all three were present. The consumption of B. tabaci was similar whether it was alone or together with A. gossypii. However, the presence of aphids reduced predation on the invasive thrips. Thus, some invasive prey may be incorporated into the prey range of a native generalist predator even in the presence of preferred native prey. PMID:27391468

Impact of straw mulch on populations of onion thrips (Thysanoptera: Thripidae) in onion.

Science.gov (United States)

Larentzaki, E; Plate, J; Nault, B A; Shelton, A M

2008-08-01

Development of insecticide resistance in onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), populations in onion (Allium spp.) fields and the incidence of the T. tabaci transmitted Iris yellow spot virus have stimulated interest in evaluating alternative management tactics. Effects of straw mulch applied in commercial onion fields in muck areas of western New York were assessed in 2006 and 2007 as a possible onion thrips management strategy. In trials in which no insecticides were applied for thrips control, straw mulch-treated plots supported significantly lower T. tabaci populations compared with control plots. In both years, the action thresholds of one or three larvae per leaf were reached in straw mulch treatments between 7 and 14 d later than in the control. Ground predatory fauna, as evaluated by pitfall trapping, was not increased by straw mulch in 2006; however, populations of the common predatory thrips Aeolothrips fasciatus (L.) (Thysanoptera: Aeolothripidae) were significantly lower in straw mulch plots in both years. Interference of straw mulch in the pupation and emergence of T. tabaci was investigated in the lab and their emergence was reduced by 54% compared with bare soil. In the field the overall yield of onions was not affected by the straw mulch treatment; however, the presence of jumbo grade onions (>77 mm) was increased in 2006, but not in 2007. These results indicate that populations of T. tabaci adults and larvae can be significantly reduced by the use of straw mulch without compromising overall onion yield. The use of this cultural practice in an onion integrated pest management program seems promising.

Tissue location of resistance in apple to the rosy apple aphid established by electrical penetration graphs

NARCIS (Netherlands)

Marchetti, E.; Civolani, S.; Leis, M.; Chicca, M.; Tjallingii, W.F.; Pasqualini, E.; Baroni, P.

2009-01-01

A study of the constitutive resistance of the apple cultivar Florina, Malus domestica Borkh. (Rosaceae), to the rosy apple aphid, Dysaphis plantaginea (Passerini) (Homoptera Aphididae), was performed for the first time by the electrical penetration graph (DC-EPG) system, using the susceptible apple

Fungal Endophytes of Wild Barley and their Effects on Diuraphis noxia Population Development

Science.gov (United States)

S.L. Clement; A. Dan Wilson; D.G. Lester; C.M. Davitt

1997-01-01

Laboratory experiments were conducted to compare the expression of Diuraphis noxia (Mordvilko) (Homoptera: Aphididae) resistance in four plant introduction (PI) lines of wild barley (Hordeum) infected with different species or strains of endophytic fungi (tribe Balansieae, family Clavicipitaceae, Neotyphodium gen. nov. [formerly...

Infection of potato plants with potato leafroll virus changes attraction and feeding behaviour of Myzus persicae

NARCIS (Netherlands)

Alvarez, A.E.; Garzo, E.; Verbeek, M.; Vosman, B.; Dicke, M.; Tjallingii, W.F.

2007-01-01

Potato leafroll virus (PLRV; genus Polerovirus, family Luteoviridae) is a persistently transmitted circulative virus that depends on aphids for spreading. The primary vector of PLRV is the aphid Myzus persicae (Sulzer) (Homoptera: Aphididae). Solanum tuberosum L. potato cv. Kardal (Solanaceae) has a

Characterizing pathways of invasion using Sternorryhncha on imported plant material in cargo

Science.gov (United States)

Timothy T. Work

2011-01-01

Non-indigenous Homoptera, mainly scales, aphids, and mealy bugs, intercepted on plants destined for cultivation represent an elevated risk for the establishment of invasive insects in North America. These insects [grouped as the suborder Sternorrhyncha] are often parthenogenic and are imported on viable host plants.

Resistance to lettuce aphid (Nasonovia ribisnigri) biotype 0 in wild lettuce accessions PI 491093 and PI 274378

Science.gov (United States)

Lettuce aphid, Nasonovia ribisnigri Mosley (Homoptera : Aphididae), is a major insect pest of lettuce, Lactuca sativa L, in many commercial lettuce productions areas around the world. Resistance to lettuce aphid was first reported in Lactuca virosa L. accession IVT 280 and characterized as complete,...

Regional and temporal variation in susceptibility to lambda-cyhalothrin in onion thrips, Thrips tabaci (Thysanoptera: Thripidae), in onion fields in New York.

Science.gov (United States)

Shelton, A M; Nault, B A; Plate, J; Zhao, J Z

2003-12-01

Populations of onion thrips, Thrips tabaci Lindeman, from commercial onion fields in New York were evaluated for their susceptibility to the commonly used pyrethroid, lambda-cyhalothrin (Warrior T), using a novel system called the Thrips Insecticide Bioassay System (TIBS). To use TIBS, thrips are collected directly from the plant into an insecticide-treated 0.5-ml microcentrifuge tube that has a flexible plastic cap with a small well into which 0.08 ml of a 10% sugar-water solution with food colorant is deposited. The solution is sealed into the well with a small piece of stretched parafilm through which the thrips can feed on the solution. Thrips mortality is assessed after 24 h with the help of a dissecting stereoscope. In 2001, onion thrips populations were collected from 16 different sites and resistance ratios were >1,000 in five populations. Percent mortality at 100 ppm, a recommended field rate, varied from 9 to 100%, indicating high levels of variation in susceptibility. Particular instances of resistance appeared to be the result of practices within an individual field rather than a regional phenomenon. In 2002, we also observed large differences in onion thrips susceptibility, not only between individual fields but also between thrips collected in a single field at mid season and late season, again suggesting that insecticide-use practices within an individual field caused differences in susceptibility. Additional tests indicated no differences in susceptibility between adult and larval onion thrips populations and only relatively minor differences between populations collected from different parts of the same field. Using TIBS, several populations of onion thrips with different susceptibilities to lambda-cyhalothrin were identified and then subjected to lambda-cyhalothrin-treated onion plants. There was a highly significant positive relationship between percent mortality of thrips from TIBS and percent mortality from the treated onion plants, indicating

Previsual detection of two conifer-infesting adelgid species in North American forest

Science.gov (United States)

Stephen Cook; Karen Humes; Ryan Hruska; Christopher Williams; Grant Fraley

2010-01-01

The balsam woolly adelgid, Adelges piceae, and hemlock woolly adelgid, A. tsugae (Homoptera: Adelgidae), are invasive pests of coniferous forests in both the Eastern and Western United States. Balsam woolly adelgid is capable of attacking and killing native North American firs, with Fraser fir (Abies fraseri...

Short Communication: Occurrence of the pea aphid, Acyrthosiphon ...

African Journals Online (AJOL)

The occurrence of pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), on wild annual and perennial leguminous plants was studied at two locations (Adet and Wondata) in West Gojam, Ethiopia in 1999/2000 seasons. Annual and perennial leguminous wild or volunteer plants encountered in the study areas ...

Intensidade de ataque de tripes, de alternaria e da queima-das-pontas em cultivares de cebola

OpenAIRE

Leite,Germano L.D.; Santos,Marília Cristina dos; Rocha,Silma L.; Costa,Cândido A. da; Almeida,Chrystian I. Maia e

2004-01-01

Avaliou-se a intensidade de ataque de Thrips tabaci Lind., a incidência de Alternaria porri (Ellis) e Botrytis squamosa J.C. Walker em nove cultivares de cebola [Aurora, Primavera, CNPH 6400, Crioula Alto-Vale, Vale-Ouro (IPA 11), Franciscana (IPA-16), Piraouro, Conquista e Serrana], num experimento no delineamento em blocos casualizados com cinco repetições. Foram feitas avaliações semanais, do transplantio até a colheita, em dez plantas/parcela do número de T. tabaci presente na bainha das ...

Whiteflies interfere with indirect plant defense against spider mites in Lima bean

Science.gov (United States)

Zhang, Peng-Jun; Zheng, Si-Jun; van Loon, Joop J. A.; Boland, Wilhelm; David, Anja; Mumm, Roland; Dicke, Marcel

2009-01-01

Plants under herbivore attack are able to initiate indirect defense by synthesizing and releasing complex blends of volatiles that attract natural enemies of the herbivore. However, little is known about how plants respond to infestation by multiple herbivores, particularly if these belong to different feeding guilds. Here, we report the interference by a phloem-feeding insect, the whitefly Bemisia tabaci, with indirect plant defenses induced by spider mites (Tetranychus urticae) in Lima bean (Phaseolus lunatus) plants. Additional whitefly infestation of spider-mite infested plants resulted in a reduced attraction of predatory mites (Phytoseiulus persimilis) compared to attraction to plants infested by spider mites only. This interference is shown to result from the reduction in (E)-β-ocimene emission from plants infested by both spider mites and whiteflies. When using exogenous salicylic acid (SA) application to mimic B. tabaci infestation, we observed similar results in behavioral and chemical analyses. Phytohormone and gene-expression analyses revealed that B. tabaci infestation, as well as SA application, inhibited spider mite-induced jasmonic acid (JA) production and reduced the expression of two JA-regulated genes, one of which encodes for the P. lunatus enzyme β-ocimene synthase that catalyzes the synthesis of (E)-β-ocimene. Remarkably, B. tabaci infestation concurrently inhibited SA production induced by spider mites. We therefore conclude that in dual-infested Lima bean plants the suppression of the JA signaling pathway by whitefly feeding is not due to enhanced SA levels. PMID:19965373

Diversity and Phylogenetic Analyses of Bacterial Symbionts in Three Whitefly Species from Southeast Europe

Science.gov (United States)

Skaljac, Marisa; Zanic, Katja; Puizina, Jasna; Lepen Pleic, Ivana; Ghanim, Murad

2017-01-01

Bemisia tabaci (Gennadius), Trialeurodes vaporariorum (Westwood), and Siphoninus phillyreae (Haliday) are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts detected. Arsenophonus and Hamiltonella were the most prevalent symbionts in all three whitefly species. Rickettsia was found to infect mainly B. tabaci, while Wolbachia mainly infected both B. tabaci and S. phillyreae. Furthermore, Cardinium was rarely found in the investigated whitefly populations, while Fritschea was never found in any of the whitefly species tested. Phylogenetic analyses revealed a diversity of several symbionts (e.g., Hamiltonella, Arsenophonus, Rickettsia), which appeared in several clades. Reproductively isolated B. tabaci and T. vaporariorum shared the same (or highly similar) Hamiltonella and Arsenophonus, while these symbionts were distinctive in S. phillyreae. Interestingly, Arsenophonus from S. phillyreae did not cluster with any of the reported sequences, which could indicate the presence of Arsenophonus, not previously associated with whiteflies. In this study, symbionts (Wolbachia, Rickettsia, and Cardinium) known to infect a wide range of insects each clustered in the same clades independently of the whitefly species. These results indicate horizontal transmission of bacterial symbionts between reproductively isolated whitefly species, a mechanism that can establish new infections that did not previously exist in whiteflies. PMID:29053633

Diversity and Phylogenetic Analyses of Bacterial Symbionts in Three Whitefly Species from Southeast Europe

Directory of Open Access Journals (Sweden)

Marisa Skaljac

2017-10-01

Full Text Available Bemisia tabaci (Gennadius, Trialeurodes vaporariorum (Westwood, and Siphoninus phillyreae (Haliday are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts detected. Arsenophonus and Hamiltonella were the most prevalent symbionts in all three whitefly species. Rickettsia was found to infect mainly B. tabaci, while Wolbachia mainly infected both B. tabaci and S. phillyreae. Furthermore, Cardinium was rarely found in the investigated whitefly populations, while Fritschea was never found in any of the whitefly species tested. Phylogenetic analyses revealed a diversity of several symbionts (e.g., Hamiltonella, Arsenophonus, Rickettsia, which appeared in several clades. Reproductively isolated B. tabaci and T. vaporariorum shared the same (or highly similar Hamiltonella and Arsenophonus, while these symbionts were distinctive in S. phillyreae. Interestingly, Arsenophonus from S. phillyreae did not cluster with any of the reported sequences, which could indicate the presence of Arsenophonus, not previously associated with whiteflies. In this study, symbionts (Wolbachia, Rickettsia, and Cardinium known to infect a wide range of insects each clustered in the same clades independently of the whitefly species. These results indicate horizontal transmission of bacterial symbionts between reproductively isolated whitefly species, a mechanism that can establish new infections that did not previously exist in whiteflies.

Significance and transmission of maize streak virus disease in Africa ...

African Journals Online (AJOL)

STORAGESEVER

2008-12-29

Dec 29, 2008 ... soil nutrients, altitude and temperature on the biology of maize streak virus (MSV) / vector populations is discussed. ... status of maize host plants and its effects on population dynamics of Cicadulina mbila Naudé. (Homoptera: ..... time necessary for the leafhopper to reach the mesophyll of the leaf and ingest ...

Ocorrência de mosca-branca em Annona squamosa no estado de São Paulo

Directory of Open Access Journals (Sweden)

Maria José De Marchi Garcia

2013-12-01

Full Text Available No Brasil, é restrito o conhecimento sobre distribuição geográfica e plantas hospedeiras de moscas-brancas (Hemiptera: Aleyrodidae, principalmente em plantas cultivadas. Nesta comunicação, é registrada a ocorrência de Aleurodicus mirabilis (Cockerell, 1898 em altas infestações em fruta-do-conde (Annona squamosa Linnaeus, 1753 no estado de São Paulo, Brasil.

Effect of solid and aqueous extract of vermicompost on growth characteristics of tomato and greenhouse whitefly (Trialeurodes vaporariorum)

OpenAIRE

A. Peimani Foroushani; N. Poorjavad; M. Haghigh; J. Khajehali

2016-01-01

Considering the increase of using vermicompost fertilizers in greenhouse cultivation, effect of vermicompost application on growth characteristics of tomato and one of its major pests [greenhouse whitefly, Trialeurodes vaporariorum (Hem:Aleyrodidae)] was investigated. The experiment consisted of five treatments: control (without vermicompost), 30% and 60% solid vermicompost fertilizer, and 40% and 20% aqueous extracts of vermicompost. Effect of vermicompost on greenhouse whitefly was tested f...

Impacto da adubação orgânica sobre a incidência de tripes em cebola Impact of the organic fertilization on onion thrips incidence

Directory of Open Access Journals (Sweden)

Paulo Antônio de S. Gonçalves

2003-09-01

Full Text Available Analisou-se a relação entre adubação orgânica e a incidência de Thrips tabaci Lind. em cebola (Allium cepa L, na EE de Ituporanga, entre agosto e dezembro de 1998. Os tratamentos foram determinados de acordo com a necessidade de N para a cultura pela análise de solo. Empregou-se como fonte orgânica diversos adubos fornecendo 75 Kg/ha de N (esterco suíno; adubo Barriga Verde® proveniente de esterco de aves; composto orgânico; esterco de peru; húmus; 37,5 Kg/ha de N (metade da dose normal com esterco de suíno; as testemunhas foram adubação mineral fornecendo 30-120-60 kg/ha de N-P2O5-K2O e o dobro da dose (60-240-120 kg/ha de N-P2O5-K2O; e testemunha sem adubação. Nenhum tratamento apresentou incidência de T. tabaci superior à testemunha sem adubo. A adubação mineral em relação à orgânica não favoreceu significativamente a incidência de T. tabaci . O processo de conversão do manejo do solo da área experimental de convencional para orgânico pode ter favorecido a infestação similar do inseto entre tratamentos. No período de maior incidência de T. tabaci, a relação com nutrientes foi descrita por um modelo envolvendo K/Zn, B e N de maneira positiva. A correlação entre nutrientes e T. tabaci não foi linear na maioria das avaliações. A adubação orgânica pode substituir a adubação mineral na cultura da cebola, pois foi possível atingir níveis de produtividade similares para ambos tratamentos.The impact of organic fertilization on the incidence of thrips (Thrips tabaci Lind. on onion was evaluated at Ituporanga Experimental Station in Santa Catarina State, Brazil, from August to December, 1998. The treatments using organic fertilization were based on the N needs determined by previous soil analysis. Using different organic sources were 75.0 Kg/ha of N (swine manure; Barriga Verde® poultry manure; compost; turkey manure; humus; 37.5 Kg/ha of N (swine manure half regular rate; two chemically fertilized

Establishment of the cytoplasmic incompatibility-inducing Wolbachia strain wMel in an important agricultural pest insect.

Science.gov (United States)

Zhou, Xiao-Fei; Li, Zheng-Xi

2016-12-16

The wMel Wolbachia strain was known for cytoplasmic incompatibility (CI)-induction and blocking the transmission of dengue. However, it is unknown whether it can establish and induce CI in a non-dipteran host insect. Here we artificially transferred wMel from Drosophila melanogaster into the whitefly Bemisia tabaci. Fluorescence in situ hybridisation demonstrated that wMel had successfully transfected the new host. Reciprocal crossing was conducted with wMel-transfected and wild-type isofemale lines, indicating that wMel could induce a strong CI without imposing significant cost on host fecundity. We then determined the maternal transmission efficiency of wMel in the offspring generations, showing a fluctuating trend over a period of 12 generations. We thus detected the titre of wMel during different developmental stages and in different generations by using real-time quantitative PCR, revealing a similar fluctuating mode, but it was not significantly correlated with the dynamics of transmission efficiency. These results suggest that wMel can be established in B.tabaci, a distantly related pest insect of agricultural importance; moreover, it can induce a strong CI phenotype in the recipient host insect, suggesting a potential for its use in biological control of B. tabaci.

Incidência de insetos e doenças em cultivares e populações de cebola Incidence of insects and diseases in onion cultivars and populations

Directory of Open Access Journals (Sweden)

Germano LD Leite

2007-03-01

Full Text Available A cebola é uma das hortaliças mais importantes no Brasil. Contudo, é atacada por insetos e doenças, tais como Thrips tabaci Lindeman, Botrytis squamosa, Alternaria porri e Colletotrichum gloeosporioides f.sp. cepae. Este trabalho teve como objetivo avaliar a incidência de tripes, queima-das-pontas, mancha-de-alternaria e mal-de-sete-voltas em oito populações elite do programa de melhoramento genético de cebola da Embrapa ("CNPH 6415", "CNPH 6074", "CNPH 6244", "CNPH 6400 Chata", "CNPH 6400 Redonda", "Valencianita" x "Aurora", "Primavera" x "Pera Norte" e "Pera Norte" x "Primavera" e oito variedades comerciais (Granex 429, BRS Cascata, Belém IPA 9, Crioula Alto Vale, Bola Precoce, Primavera, Régia e 1015 Y. Em regiões de alta incidência de C. gloeosporioides, os materiais recomendados são "CNPH 6415", "CNPH 6074" e "CNPH 6244"; de A. porri são "CNPH 6415", "CNPH 6074", "CNPH 6244", "BRS Cascata", "Valencianita" x "Aurora", "Primavera" x "Pera Norte", "Belém IPA 9", "Bola Precoce", "Primavera" e "Régia"; e de T. tabaci são "CNPH 6415", "CNPH 6074", "Granex 429", "Bola Precoce", "Primavera" e "Régia". As populações "CNPH 6415" e "CNPH 6074" apresentam resistência a esses três agentes etiológicos. Por outro lado, "CNPH 6400 Chata", "CNPH 6400 Redonda" e "1015 Y" são suscetíveis a C. gloeosporioides, A. porri e T. tabaci. Todos os materiais estudados sofrem ataque considerável de B. squamosa.Onion (Allium cepa L. is one of the most important vegetable crops in Brazil. It is attacked by insects and diseases, such as Thrips tabaci Lindeman (Thysanoptera: Thripidae, Botrytis squamosa (J.C. Walker, Alternaria porri (Ellis and Colletotrichum gloeosporioides f.sp. cepae Penz. This work evaluated the incidence of thrips, onion leaf blight, purple blotch, and smudge in eight elite populations of the Embrapa's onion breeding program ("CNPH 6415", "CNPH 6074", "CNPH 6244", "CNPH 6400 Chata", "CNPH 6400 Redonda", "Valencianita" x

Identification of Thrips Species on Garlic Fields in Hamedan Province and Determination of Dominant Species

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Majid Mirab-balou

2016-09-01

Full Text Available Introduction: Garlic (Allium sativum (family Amaryllidaceae are one of important crops in Hamedan province. There are several insects and mites that by feeding on this plant cause to damage garlic yield. Among the insect pests, the most dangerous pests of garlic are thrips species (Insecta: Thysanoptera. In this group, onion thrips, Thrips tabaci Lindeman is widely distributed and is a dominant species. Its sap sucking causes tiny and silvery spots on the leaves that may spread all over the leaf surface with an unfavorable effect on yield production. In addition, imagoes and larvae living and feeding on this plant cause more serious damages. Due to serious damage of thrips in garlic fields of Hamedan province, it is necessary to identify thripsspecies for pest control programs. Materials and Methods: Thrips specimens were collected on leaves of garlic in Hamedan province (Maryanaj and Heydareh situated in the west of Iran, during 2012–2013. Herein, specimens were collected by shaking plants to white dish and specimens were kept in 70 % ethanol and transferred to the laboratory. All collected material was macerated in 5% KOH and subjected to dehydration in an ethanol series before being mounted onto glass slides. Subsequently, thrips specimens mounted onto slides in Hoyer’s medium form of the protocol given in Mirab-balou and Chen (2010. All descriptions, measurements and photos were made with a Leica DM IRB microscope, with a Leica Image 1000 system. Thrips specimens were identified by author in species level. Specimens are deposited in the collection of Department of Plant Protection, College of Agriculture, Ilam University, Iran (ILAMU. In addition, dominant thrips species were also determined. For this purpose, regular samplings were done in fields of two regions of Hamedan province every two weeks, and totally, 2040 specimens (adult were collected. Results and Discussion: The world fauna of Thysanoptera, are presently known to be

DIVERSITY AND DISTRIBUTION OF WHITEFLIES IN ...

African Journals Online (AJOL)

ACSS

ecosystems and are valuable indicators of their health. Insects are extremely diverse and important to ecosystems ... essential economic benefits and services to human society - such ..... Bemisia tabaci on cotton and cucumber. Environmental.

Annual predictions of the peak numbers of Sitobion avenae infesting winter wheat

Czech Academy of Sciences Publication Activity Database

Honěk, A.; Martinková, Z.; Dixon, Anthony F. G.; Saska, P.

2017-01-01

Roč. 141, č. 5 (2017), s. 352-362 ISSN 0931-2048 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:86652079 Keywords : metopolophium-dirhodum wlk * cereal aphid populations * rhopalosiphum-padi l * english grain aphid * field populations * growth-stages * fixed levels * yield loss * homoptera * dynamics * abundance * ears * growth * leaves * maximum * population Subject RIV: EH - Ecology, Behaviour OBOR OECD: Biodiversity conservation Impact factor: 1.641, year: 2016

Tomato Infection by Whitefly-Transmitted Circulative and Non-Circulative Viruses Induce Contrasting Changes in Plant Volatiles and Vector Behaviour.

Science.gov (United States)

Fereres, Alberto; Peñaflor, Maria Fernanda G V; Favaro, Carla F; Azevedo, Kamila E X; Landi, Carolina H; Maluta, Nathalie K P; Bento, José Mauricio S; Lopes, Joao R S

2016-08-11

Virus infection frequently modifies plant phenotypes, leading to changes in behaviour and performance of their insect vectors in a way that transmission is enhanced, although this may not always be the case. Here, we investigated Bemisia tabaci response to tomato plants infected by Tomato chlorosis virus (ToCV), a non-circulative-transmitted crinivirus, and Tomato severe rugose virus (ToSRV), a circulative-transmitted begomovirus. Moreover, we examined the role of visual and olfactory cues in host plant selection by both viruliferous and non-viruliferous B. tabaci. Visual cues alone were assessed as targets for whitefly landing by placing leaves underneath a Plexiglas plate. A dual-choice arena was used to assess whitefly response to virus-infected and mock-inoculated tomato leaves under light and dark conditions. Thereafter, we tested the whitefly response to volatiles using an active air-flow Y-tube olfactometer, and chemically characterized the blends using gas chromatography coupled to mass spectrometry. Visual stimuli tests showed that whiteflies, irrespective of their infectious status, always preferred to land on virus-infected rather than on mock-inoculated leaves. Furthermore, whiteflies had no preference for either virus-infected or mock-inoculated leaves under dark conditions, but preferred virus-infected leaves in the presence of light. ToSRV-infection promoted a sharp decline in the concentration of some tomato volatiles, while an increase in the emission of some terpenes after ToCV infection was found. ToSRV-viruliferous whiteflies preferred volatiles emitted from mock-inoculated plants, a conducive behaviour to enhance virus spread, while volatiles from ToCV-infected plants were avoided by non-viruliferous whiteflies, a behaviour that is likely detrimental to the secondary spread of the virus. In conclusion, the circulative persistent begomovirus, ToSRV, seems to have evolved together with its vector B. tabaci to optimise its own spread. However

Tomato Infection by Whitefly-Transmitted Circulative and Non-Circulative Viruses Induce Contrasting Changes in Plant Volatiles and Vector Behaviour

Directory of Open Access Journals (Sweden)

Alberto Fereres

2016-08-01

Full Text Available Virus infection frequently modifies plant phenotypes, leading to changes in behaviour and performance of their insect vectors in a way that transmission is enhanced, although this may not always be the case. Here, we investigated Bemisia tabaci response to tomato plants infected by Tomato chlorosis virus (ToCV, a non-circulative-transmitted crinivirus, and Tomato severe rugose virus (ToSRV, a circulative-transmitted begomovirus. Moreover, we examined the role of visual and olfactory cues in host plant selection by both viruliferous and non-viruliferous B. tabaci. Visual cues alone were assessed as targets for whitefly landing by placing leaves underneath a Plexiglas plate. A dual-choice arena was used to assess whitefly response to virus-infected and mock-inoculated tomato leaves under light and dark conditions. Thereafter, we tested the whitefly response to volatiles using an active air-flow Y-tube olfactometer, and chemically characterized the blends using gas chromatography coupled to mass spectrometry. Visual stimuli tests showed that whiteflies, irrespective of their infectious status, always preferred to land on virus-infected rather than on mock-inoculated leaves. Furthermore, whiteflies had no preference for either virus-infected or mock-inoculated leaves under dark conditions, but preferred virus-infected leaves in the presence of light. ToSRV-infection promoted a sharp decline in the concentration of some tomato volatiles, while an increase in the emission of some terpenes after ToCV infection was found. ToSRV-viruliferous whiteflies preferred volatiles emitted from mock-inoculated plants, a conducive behaviour to enhance virus spread, while volatiles from ToCV-infected plants were avoided by non-viruliferous whiteflies, a behaviour that is likely detrimental to the secondary spread of the virus. In conclusion, the circulative persistent begomovirus, ToSRV, seems to have evolved together with its vector B. tabaci to optimise its own

Biochemical factors associated with cassava resistance to whitefly

African Journals Online (AJOL)

ACSS

2017-08-17

Aug 17, 2017 ... interactions having been suggested to be ... (Achidi et al., 2008); free sugars, protein and ... would elucidate the contribution of these ...... mays. Journal of Molecular Plant-Microbe .... Population dynamics of Bemisia tabaci and.

Acyrthosiphon pisum (Harris) (Homoptera: Aphididae) infestation ...

African Journals Online (AJOL)

Plant height, plant density per 0.25 m2, number of pea aphids and parasitoids per plant, ladybird beetles per plot, and finally grain yield per plot were recorded. Based on the results of the ANOVA, plant height was significantly different between treated and untreated plots especially after the vegetative stage. The density of ...

Identification and validation of a virus-inducible ta-siRNA-generating ...

Indian Academy of Sciences (India)

2016-02-01

Feb 1, 2016 ... and bacterial spot disease resistance protein Bs4 gene. ... whitefly (Bemisia tabaci) and infect a variety of crops, both monocot and dicot, causing ..... virus variant associated with newly emerging yellow mosaic disease of ...

RNA viral metagenome of whiteflies leads to the discovery and characterization of a whitefly-transmitted carlavirus in North America.

Science.gov (United States)

Rosario, Karyna; Capobianco, Heather; Ng, Terry Fei Fan; Breitbart, Mya; Polston, Jane E

2014-01-01

Whiteflies from the Bemisia tabaci species complex have the ability to transmit a large number of plant viruses and are some of the most detrimental pests in agriculture. Although whiteflies are known to transmit both DNA and RNA viruses, most of the diversity has been recorded for the former, specifically for the Begomovirus genus. This study investigated the total diversity of DNA and RNA viruses found in whiteflies collected from a single site in Florida to evaluate if there are additional, previously undetected viral types within the B. tabaci vector. Metagenomic analysis of viral DNA extracted from the whiteflies only resulted in the detection of begomoviruses. In contrast, whiteflies contained sequences similar to RNA viruses from divergent groups, with a diversity that extends beyond currently described viruses. The metagenomic analysis of whiteflies also led to the first report of a whitefly-transmitted RNA virus similar to Cowpea mild mottle virus (CpMMV Florida) (genus Carlavirus) in North America. Further investigation resulted in the detection of CpMMV Florida in native and cultivated plants growing near the original field site of whitefly collection and determination of its experimental host range. Analysis of complete CpMMV Florida genomes recovered from whiteflies and plants suggests that the current classification criteria for carlaviruses need to be reevaluated. Overall, metagenomic analysis supports that DNA plant viruses carried by B. tabaci are dominated by begomoviruses, whereas significantly less is known about RNA viruses present in this damaging insect vector.

RNA viral metagenome of whiteflies leads to the discovery and characterization of a whitefly-transmitted carlavirus in North America.

Directory of Open Access Journals (Sweden)

Karyna Rosario

Full Text Available Whiteflies from the Bemisia tabaci species complex have the ability to transmit a large number of plant viruses and are some of the most detrimental pests in agriculture. Although whiteflies are known to transmit both DNA and RNA viruses, most of the diversity has been recorded for the former, specifically for the Begomovirus genus. This study investigated the total diversity of DNA and RNA viruses found in whiteflies collected from a single site in Florida to evaluate if there are additional, previously undetected viral types within the B. tabaci vector. Metagenomic analysis of viral DNA extracted from the whiteflies only resulted in the detection of begomoviruses. In contrast, whiteflies contained sequences similar to RNA viruses from divergent groups, with a diversity that extends beyond currently described viruses. The metagenomic analysis of whiteflies also led to the first report of a whitefly-transmitted RNA virus similar to Cowpea mild mottle virus (CpMMV Florida (genus Carlavirus in North America. Further investigation resulted in the detection of CpMMV Florida in native and cultivated plants growing near the original field site of whitefly collection and determination of its experimental host range. Analysis of complete CpMMV Florida genomes recovered from whiteflies and plants suggests that the current classification criteria for carlaviruses need to be reevaluated. Overall, metagenomic analysis supports that DNA plant viruses carried by B. tabaci are dominated by begomoviruses, whereas significantly less is known about RNA viruses present in this damaging insect vector.

Susceptibility of ornamental pepper banker plant candidates to common greenhouse pests

Science.gov (United States)

Susceptibility of four potential ornamental pepper banker plant candidates [Black Pearl (BP), Explosive Ember (EE), Masquerade (MA), Red Missile (RM), and a commercial pepper cultivar Blitz (BL)] were evaluated against three common greenhouse pests - Bemisia tabaci, Polyphagotarsonemus latus and Fra...

Biological activity of sugarcane pyroligneous acid against ...

African Journals Online (AJOL)

aghomotsegin

2013-10-23

Oct 23, 2013 ... most used for charcoal production is the Pinus elliottii var. .... de produtos naturais para o controle de Bemisia tabaci biótipo B .... larva. J. Econ. Entomol. 76:219-222. Zandersons J, Gravitis J, Kokorevics A, Zhurinsh A, ...

Transcriptomics-guided development of RNA interference strategies to manage whiteflies: a globally distributed vector of crop viruses

Science.gov (United States)

Over 300 viruses are transmitted by the whitefly, Bemisia tabaci, with 90% of them belonging to the genus, Begomovirus. Begomoviruses are exclusively transmitted by whiteflies to a range of agriculture crops, resulting in billions of dollars lost annually, while jeopardizing food security worldwide....

Torradoviruses are transmitted in a semi-persistent and stylet-borne manner by three whitefly vectors

NARCIS (Netherlands)

Verbeek, M.; Bekkum, van P.J.; Dullemans, A.M.; Vlugt, van der R.A.A.

2014-01-01

Members of the genus Torradovirus (family Secoviridae, type species Tomato torrado virus, ToTV) are spherical plant viruses transmitted by the whitefly species Trialeurodes vaporariorum and Bemisia tabaci. Knowledge on the mode of vector transmission is lacking for torradoviruses. Here, the mode of

Stage-Related Defense Response Induction in Tomato Plants by Nesidiocoris tenuis

Science.gov (United States)

Naselli, Mario; Urbaneja, Alberto; Siscaro, Gaetano; Jaques, Josep A.; Zappalà, Lucia; Flors, Víctor; Pérez-Hedo, Meritxell

2016-01-01

The beneficial effects of direct predation by zoophytophagous biological control agents (BCAs), such as the mirid bug Nesidiocoris tenuis, are well-known. However, the benefits of zoophytophagous BCAs’ relation with host plants, via induction of plant defensive responses, have not been investigated until recently. To date, only the females of certain zoophytophagous BCAs have been demonstrated to induce defensive plant responses in tomato plants. The aim of this work was to determine whether nymphs, adult females, and adult males of N. tenuis are able to induce defense responses in tomato plants. Compared to undamaged tomato plants (i.e., not exposed to the mirid), plants on which young or mature nymphs, or adult males or females of N. tenuis fed and developed were less attractive to the whitefly Bemisia tabaci, but were more attractive to the parasitoid Encarsia formosa. Female-exposed plants were more repellent to B. tabaci and more attractive to E. formosa than were male-exposed plants. When comparing young- and mature-nymph-exposed plants, the same level of repellence was obtained for B. tabaci, but mature-nymph-exposed plants were more attractive to E. formosa. The repellent effect is attributed to the signaling pathway of abscisic acid, which is upregulated in N. tenuis-exposed plants, whereas the parasitoid attraction was attributed to the activation of the jasmonic acid signaling pathway. Our results demonstrate that all motile stages of N. tenuis can trigger defensive responses in tomato plants, although these responses may be slightly different depending on the stage considered. PMID:27472328

Preparation of Chitin, Study of Physicochemical Properties and Biopesticide Activities

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Yuli Rohyami

2013-08-01

Full Text Available Chitin was preparated from shrimp shells by chemically method. Preparation was carried out by deproteination shrimp shells powder < 150 mesh with 1 - 2 M NaOH, demineralization followed by reaction with 1.0 M HCl and depigmentation with (1 : 2 : 4, v/v of chloroform : methanol : water. Physicochemical properties of chitin was determined from characterization of infrared spectra, ash value, loss on drying and total of nitrogen. Biopesticide activities of chitin was done to pest Bemisia tabaci at guava leaves with various concentration from 0.5 to 2.0 % chitin on 3 % v/v acetic acid. This study indicated that concentration of NaOH on deproteination process effected to its physicochemicals properties. Effectivity of 2 M NaOH on deproteination reaction was higher than 1 M NaOH . The degree of chitin deacetylation from 2 M NaOH was 13.61% and had lower molar ratio of total nitrogen. The degree of deacetylation of chitin from 1 M NaOH had lower and had higher molar ratio of total nitrogen. Physicochemicals properties of chitin quite an impact on its ability to reduce pest Bemisia tabaci. Biopesticide activity assay showed that treatment for 2 days on average mortality rate of 13.83%. Deacetylation of chitin which has a higher degree have a greaterability biopesticide with a mortality rate of up to 38.24%. This study the effect of deproteination process to biopesticide activities of chitin.Key Words : chitin, degree of deacetilation, molar ratio, biopesticide, Bemisia tabaci

Plantas hospederas de Aphis gossypii (Aphididae), vector de virus del melón Cucumis melo (Cucurbitaceae) en Costa Rica

OpenAIRE

Sánchez, M.V.; Agüero, R.; Rivera, C.

2001-01-01

Se identificaron las especies hospederas naturales de Aphis gossypii Glover (Aphididae: Homoptera) en plantaciones comerciales de melón para la exportación en Costa Rica. El estudio se realizó en dos fincas, ubicadas una en la provincia de Guanacaste y la otra en la provincia de Puntarenas, correspondientes a dos zonas de vida vegetal diferentes. Se identificaron como especies hospederas del áfido todas aquellas especies vegetales en las que se observó la presencia del áfido en su forma ápter...

Isaria poprawskii sp. nov. (Hypocreales: Cordycipitacae), a new entomopathogenic fungus from Texas affecting sweet potato whitefly

Science.gov (United States)

Isaria poprawskii is described as a new entomopathogenic species similar to Isaria javanica (=Paecilomyces javanicus). It was discovered ont he sweet potato whitefly, Bemisia tabaci biotype B in the Lower Rio Grande Valley of Texas (LRGV), USA. Morphological and DNA examinations indicated the dist...

Identification of whitefly resistance in tomato and hot pepper

NARCIS (Netherlands)

Firdaus, S.

2012-01-01

Key words: Capsicum, Bemisia tabaci, trichome density, cuticle thickness
Whitefly is economically one of the most threatening pests of pepper worldwide, which is mainly caused by its ability to transmit many different viruses. In this research, we characterized pepper germplasm to identify

Effect of woodlots on thrips density in leek fields: a landscape analysis

NARCIS (Netherlands)

Belder, den E.; Elderson, J.; Brink, van den W.J.; Schelling, G.C.

2002-01-01

The effect of woodlots, natural areas and agricultural land in the landscape on a generalist herbivore insect species in cropland was investigated. The abundance of onion thrips (Thrips tabaci) was compared in leek (Allium porrum) fields in 43 agricultural landscape plots of different sizes in The

Earliness, leaf surface wax and sugar content predict varietal differences for thrips damage in cabbage

NARCIS (Netherlands)

Voorrips, R.E.; Steenhuis-Broers, M.M.; Tiemens-Hulscher, M.; Lammerts Van Bueren, E.

2010-01-01

When cabbage is cultivated for storage in the Netherlands, it is usually harvested around mid-October. This type of cabbage crop may be severely damaged by thrips (Thrips tabaci). The thrips population on the plants and the more severe symptoms develop mostly during September and October. Also

The perspective of sweetpotato chlorotic stunt virus in sweetpotato ...

African Journals Online (AJOL)

The virus is transmitted by the whitefly species, Bemisia tabaci and Trialeurodes abutilonea, in a semi-persistent fashion. ... yields being small, and the major effect of SPCSV in constraining the yields of sweetpotato is perhaps through preventing the cultivation of high yielding but SPVD-susceptible sweetpotato cultivars.

New experimental tools for bioassays with whitefly in laboratory Novas ferramentas experimentais para ensaios com mosca-branca em laboratório

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Thiago Luis Martins Fanela

2012-12-01

Full Text Available The objective of this work was to develop an experimental kit for assessments of repellency, deterrence for oviposition, and insecticidal activity on adults of the whitefly Bemisia tabaci biotype B. The kit, which consisted of arenas and nebulizer, was effective for conducting bioassays, and the application of aqueous extracts by inhaler was adequate. The techniques are simple, cheap, and may contribute to research on this insect.O objetivo deste trabalho foi desenvolver um kit experimental para avaliações de repelência, deterrência à oviposição e atividade inseticida a adultos de mosca-branca, Bemisia tabaci biótipo B. O kit, constituído de arenas e nebulizador, foi eficaz para realização dos bioensaios, e a aplicação de extratos aquosos com o inalador foi adequada. As técnicas são simples, baratas e podem contribuir para as pesquisas com este inseto.

Eficiência de diferentes bicos e volumes de calda no controle de tripes em cebola Efficiency of different nozzle types and volume of the insecticide solution in the control of thrips in onions

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Paulo Antônio de S. Gonçalves

2000-07-01

Full Text Available O objetivo do trabalho foi avaliar a eficiência de diferentes volumes de calda e tipo de bico no controle químico de Thrips tabaci em cebola. Dois experimentos foram conduzidos na EPAGRI, Estação Experimental de Ituporanga, SC, no período de agosto a dezembro de 1996 e 1997. Os tratamentos com bico leque e respectivos níveis de vazão foram XR 110 015 VS® - 236 L/ha, XR 110 02 VS® - 316 L/ha, XR 110 03 VS® - 472 L/ha, XR 110 04 VS® - 632 L/ha, XR 110 05 VS® - 788 L/ha, TJ 60 110 02 VS® - 316 L/ha, TJ 60 110 04 VS® - 632 L/ha; com bico cone foram Conejet TSVS® - 236 L/ha, Conejet TXVK 18® - 472 L/ha, Conejet TXVK 26® - 632 L/ha, D6 Difusor V5® - 600 L/ha, além da testemunha, sem tratamento. O delineamento experimental utilizado foi blocos ao acaso com quatro repetições. O tamanho de parcela foi de 2,8 m x 3,0 m. O inseticida usado foi clorpirifós 0,72 g. i.a./ha. A amostragem de ninfas de T. tabaci foi realizada no campo em cinco plantas escolhidas ao acaso em cada parcela. A redução populacional de tripes foi semelhante entre os diferentes volumes de calda e tipos de bico utilizados. Portanto, os bicos cone e leque aplicando volumes de calda entre 236 a 788 L/ha, apresentaram a mesma eficiência no controle de T. tabaci em cebola.The objective of this work was to evaluate the efficiency of different nozzle types and volume of the insecticide solution in controlling thrips (Thrips tabaci in onions. The work was carried out from August to December, 1996 and 1997. The treatments consisted of different nozzle types (fan and cone and different flow rates. Fan nozzles were XR 110 015 VS® - 236 L/ha, XR 110 02 VS® - 316 L/ha, XR 110 03 VS® - 472 L/ha, XR 110 04 VS® - 632 L/ha, XR 110 05 VS® - 788 L/ha, TJ 60 110 02 VS® - 316 L/ha, TJ 60 110 04 VS - 632 L/ha; and cone nozzles were Conejet TSVS® - 236 L/ha, Conejet TXVK 18® - 472 L/ha, Conejet TXVK 26® - 632 L/ha, D6 Difusor V5® - 600 L/ha. Besides these treatments there

Food Composition of the Snake-Eyed Lizard, Ophisops elegans Ménétriés, 1832 (Reptilia: Sauria: Lacertidae from Gökçeada (Imbros, Turkey

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Cemal Varol Tok

2016-06-01

Full Text Available The study presents data on the food composition of the snake-eyed lizard (Ophisops elegans, from Gökçeada (Imbros, Çanakkale, Turkey. A total of 94 preys were determined in thedigestive systems of 20 individuals (10 males, 10 females examined in the study. Insects (67%constitute most of its food composition. Major prey groups in the food composition are included inAranea (13%, Lepidoptera (13%, Coleoptera (19%, and Homoptera (20% in numeric proportion.No significant difference was observed between sexes considering food composition.

2614-IJBCS-Article-Zakari Abdoul Habou

African Journals Online (AJOL)

hp

(Biobit 2X) sur la dynamique de la population de Bemisia tabaci (Gennadius ... en place un essai GIPP (Gestion Intégrée Protection Production) de la ... 80% le cas d'attaque du TYLC et le biobit dans le contrôle de la noctuelle de la tomate.

Epidemiology of Cucurbit yellow stunting disorder virus in the US Southwest and development of virus resistant melon

Science.gov (United States)

Cucurbit yellow stunting disorder virus (CYSDV), emerged in the Southwest USA in 2006, where it is transmitted by the MEAM1 cryptic species of Bemisia tabaci. The virus results in late-season infection of spring melon crops with limited economic impact; however, all summer and fall cucurbits become ...

Is the begomovirus, sweet potato leaf curl virus, really seed transmitted in sweetpotato?

Science.gov (United States)

Sweetpotato is one of the major root crops in the world and is also widely grown in the southern United States. Sweet potato leaf curl virus (SPLCV) is a begomovirus posing a serious threat to sweetpotato production worldwide and is primarily transmitted by whitefly (Bemisia tabaci) or through veget...

Phylogenetic and functional characterization of ten P450 genes from the CYP6AE subfamily of Helicoverpa armigera involved in xenobiotic metabolism

DEFF Research Database (Denmark)

Shi, Yu; Wang, Huidong; Liu, Zhi

2018-01-01

450s in this subfamily can metabolise imidacloprid, but with lower efficiency than Bemisia tabaci CYP6CM1vQ. CYP6AE20 had virtually no metabolic competence to these four compounds but could metabolise several model fluorogenic substrates. These results showed the broad substrate spectrum of H...

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

RNA interference (RNAi)-mediated gene silencing was explored for the control of sap-sucking pest Bemisia tabaci, commonly known as whitefly. dsRNAs and siRNAs were synthesized from five different genes – actin ortholog, ADP/ATP translocase, -tubulin, ribosomal protein L9 (RPL9) and V-ATPase A subunit.

Controlled transmission of African cassava mosaic virus (ACMV) by ...

African Journals Online (AJOL)

Jatropha curcas, a plant with great biodiesel potential is also used to reduce the population of whiteflies, Bemisia tabaci on cassava fields when planted as a hedge. We therefore, investigated the transmission of African cassava mosaic virus (ACMV) by the whitefly vector from cassava to seedlings of 10 accessions of J.

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African Journals Online (AJOL)

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Insect pests and diseases are a major limiting factor to cassava production in Africa. The cassava mosaic ... Strips of cotton hybrid (Sarcot 5), cassava. (Tuaka) and .... Data was log-transformed before analysis. .... B. tabaci may be able to evaluate plant sap .... competitive Congress Challenge scheme of the Task. Force on ...

genotypes for okra yellow vein mosaic virus incidence

African Journals Online (AJOL)

SAM

2014-03-19

Mar 19, 2014 ... by whitefly (Bemisia tabaci Gen.) (Rana et al., 2006). ... Solankey et al. 1337. Table 1. Scale for classifying disease reaction in okra to OYVMV disease. Symptom. Severity grade. Response value. Coefficient of infection. Reaction ..... On the basis of two season research work, it was observed that the okra ...

Assessing the effects of cultivating genetically modified glyphosate-tolerant varieties of soybeans (Glycine max (L.) Merr.) on populations of field arthropods.

Science.gov (United States)

Imura, Osamu; Shi, Kun; Iimura, Keiji; Takamizo, Tadashi

2010-01-01

We assessed the effects of cultivating two genetically modified (GM) glyphosate-tolerant soybean varieties (Glycine max (L.) Merr.) derived from Event 40-3-2 and a Japanese conventional variety on arthropods under field conditions, with weed control using glyphosate and conventional weed control for two years. Plant height and dry weight of the conventional variety were significantly larger than those of the GM varieties, but the GM varieties bore more pods than the conventional variety. We found arthropods of nine taxonomic orders (Araneae, Acari, Thysanoptera, Homoptera, Heteroptera, Coleoptera, Diptera, Lepidoptera, and Hymenoptera) on the plants. The arthropod incidence (number per plant unit weight pooled for each taxonomic order) on the soybean stems and leaves generally did not differ significantly between the GM and conventional varieties. However, the incidence of Thysanoptera and total incidence (all orders combined) were greater on the GM variety in the second year. The weed control regimes had no significant influence on the arthropod incidence on the soybean stems and leaves. The number of flower-inhabiting Thysanoptera (the dominant arthropod in the flowers) was not significantly different between the GM and conventional varieties. Asphondylia yushimai (Diptera, Cecidomyiidae) was more numerous on the pods of the GM variety in both years. Neither the soybean variety nor the weed control regime significantly affected the density of soil macro-organisms. However, the glyphosate weed control affected arthropods between the rows of plants by decreasing the abundances of Homoptera, Heteroptera, Coleoptera and Lepidoptera, and diversity of arthropods. © ISBR, EDP Sciences, 2011.

The ecology and epidemiology of whitefly-transmitted viruses in Latin America.

Science.gov (United States)

Morales, Francisco J; Jones, Peter G

2004-03-01

Whitefly-transmitted geminiviruses are the most important constraint to the production of common bean and vegetable crops in the tropical lowlands and mid-altitude valleys of Latin America. Currently, over 30 distinct species of geminiviruses that are transmitted by the whitefly Bemisia tabaci infect common bean, tomato, pepper, cucurbits and other horticultural crops. A climate probability model (using FloraMap) was obtained using data from 304 geo-referenced locations where B. tabaci and geminiviruses cause significant damage. Clustering of the 304 points produced a simple model with two climatic variables: a dry season of at least 4 months each with less than 80 mm of rain and a mean temperature of the hottest month exceeding 21 degrees C. A modified Koeppen climate classification showed that 55% of the geminivirus-affected localities are in the tropical wet/dry region, 22% in the tropical and subtropical dry/humid climates and the remaining locations belonged to the wet equatorial and trade wind litoral climates. These findings contribute to understanding whitefly/geminivirus epidemics and implementation of sustainable integrated pest and disease management practices.

(Neuroptera: Chrysopidae fed with Aleurocanthus woglumi (Hemiptera: Aleyrodidae

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Robério de Oliveira

2016-02-01

Full Text Available This study evaluated the development and reproduction of Ceraeochrysa cubana when fed the citrus blackfly Aleurocanthus woglumi. The study was carried out at the Laboratory of Entomology, Department of Plant and Environmental Sciences, Federal University of Paraíba – Areia/PB. It used a completely randomized design. The study was conducted in climate chambers, regulated to 26 ± 2°C and a relative humidity of 70 ± 10% with a 12 h photoperiod. The treatments were as follows: eggs, nymphs of only the 1st, 2nd, 3rd, or 4th instars, and nymphs of multiple instars (1st, 2nd, 3rd, and 4th instars of A. woglumi, with eggs of Sitotroga cerealella as a control. The 1st instar of C. cubana lasted 5.8 to 10.7 days, the 2nd instar lasted 6.0 to 13.3 days, and the 3rd instar lasted 8.2 to 18.5 days. The larvae of C. cubana did not survive when the food provided was only the eggs of A. woglumi, since the predator could not eat them. C. cubana, when provided nymphs of multiple instars (1st, 2nd, 3rd, and 4th instars of the citrus blackfly, had a shorter pre-pupal period and lower longevity than when consuming the eggs of S. cerealella, but the sex ratio and oviposition period were not affected. However, changes occurred in the pre-oviposition period, the total number of eggs, and the number of viable eggs.

Comparative cytogenetics of Auchenorrhyncha (Hemiptera, Homoptera): a review

Science.gov (United States)

Kuznetsova, Valentina; Aguin-Pombo, Dora

2015-01-01

Abstract A comprehensive review of cytogenetic features is provided for the large hemipteran suborder Auchenorrhyncha, which currently contains approximately 42,000 valid species. This review is based on the analysis of 819 species, 483 genera, and 31 families representing all presently recognized Auchenorrhyncha superfamilies, e.i. Cicadoidea (cicadas), Cercopoidea (spittle bugs), Membracoidea (leafhoppers and treehoppers), Myerslopioidea (ground-dwelling leafhoppers), and Fulgoroidea (planthoppers). History and present status of chromosome studies are described, as well as the structure of chromosomes, chromosome counts, trends and mechanisms of evolution of karyotypes and sex determining systems, their variation at different taxonomic levels and most characteristic (modal) states, occurrence of parthenogenesis, polyploidy, B-chromosomes and chromosome rearrangements, and methods used for cytogenetic analysis of Auchenorrhyncha. PMID:26807037

First report on the whitefly, Aleurodicus pseudugesii on the coconut palm, Cocos nucifera in Brazil.

Science.gov (United States)

de Omena, Rose Paula Mendonça; Guzzo, Elio Cesar; Ferreira, Joana Maria Santos; de Mendonça, Fernando Antônio Cavalcante; de Lima, Aurino Florencio; Racca-Filho, Francisco; Santana, Antônio Euzébio Goulart

2012-01-01

The coconut palm, Cocos nucifera L. (Arecales: Arecaceae), is currently grown extensively throughout the intertropical zones of the world, including Brazil, where it constitutes an important source of income for growers. Although whiteflies are not normally considered coconut pests, these insects can damage crops directly by sucking the sap, which weakens the plant; indirect damage may be caused by sooty mold formation over the excreted honeydew and by the transmission of pathogens. Whiteflies have infested coconut plants in the northeastern, northern, and southeastern regions of Brazil. Infested materials were collected and the causative insect was identified as Aleurodicus pseudugesii Martin (Hemiptera: Aleyrodidae). This is the first report of A. pseudugesii in Brazil as a pest of the coconut palm.

Etude morphologique et biologique de la coccinelle Scymnus couturieri Chazeau (Coleoptera-Coccinellidae prédatrice de la cochenille farineuse du manioc Phenacoccus manihoti Matile-Ferrero

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Obame Minko, D.

1999-01-01

Full Text Available Morphological and Biological Study of Scymnus couturieri Chazeau (Coleoptera-Coccinellidae, Predator of Cassava Mealybug Phenacoccus manihoti Matile-Ferrero (Homoptera-Pseudococcidae in Ivory Coast. Scymnus couturieri is a coccinellidae which was first described from Ivory Coast (2. But that morphological description was just based on the adult. The trophic action developed by Scymnus couturieri in the regulation of the abundance of the cassava mealybug led us to precise that description and to extend our knowledge of the coccinellidae by studying the morphological aspects and the biological parameters. The study brings to the fore the holometaboly development, the low fecondity and the long-lasting biological cycle of the predator.

Comparison of exclusion and imidacloprid for reduction of oviposition damage to young trees by periodical cicadas (Hemiptera: Cicadidae).

Science.gov (United States)

Ahern, Robert G; Frank, Steven D; Raupp, Michael J

2005-12-01

Insecticides are traditionally used to control periodical cicadas (Homoptera: Cicadidae) and to reduce associated injury caused by oviposition. However, research has shown that conventional insecticides have low or variable season-long efficacy in reducing injury caused by cicadas. New systemic neonicotinoid insecticides provide excellent levels of control against a variety of sucking insects. We compared the efficacy of a neonicotinoid insecticide, imidacloprid, and a nonchemical control measure, netting, to reduce cicada injury. Netted trees sustained very little injury, whereas unprotected trees were heavily damaged. Fewer eggnests, scars, and flags were observed on trees treated with imidacloprid compared with unprotected trees; however, the hatching of cicada eggs was unaffected by imidacloprid.

Comparision of the Efficiency of the Current Oils and Insecticide Compounds in Control of Greenhouse Whitefly, Trialeurodes vaporariorum (Westwood, (Hem.: Aleyrodidae on Rose and their Interaction

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Asghar Hosseininia

2017-03-01

Full Text Available Introduction: Rose plant (R osa hybrid is cultivated in nearly all regions of Iran and they are more common in the western areas of Iran. The intensive cultivation of rose often leads to injuries by pathogens or noxious animals and may require the implementation of pest control measures. Among the insect pests of roses, the greenhouse whitefly, Trialeurodes vaporariorum (Westwood (Hem.: Aleyrodidae, is fairly common pest that it is considered as major pests on roses in Iran. This pest infests the undersides of rose leaves, where the feeding adults and nymphs produce honeydew on which sooty mould grows. Considering the importance of oils in the integrated management program of this pest, in the present survey the possibility of whitefly control on rose plant were carried out to assess mortality rate (MR, synergistic rate (SR and Lc50 of the oils and common insecticide. Materials and Methods: The experiment was conducted in a greenhouse located at the experimental site of National Ornamental Plant Institute, Mahallt, Iran. The plants (Rosa hybrid Apollo were cut to stimulate rooting and then grown in plot containing a mixture of sand and sheep manure. Nine rose plant cuttings were planted in each plot with 1m2 space and 0.5 m distance each plot. So, each treatment had 9 shrubs of rose. The greenhouse whitefly T. vaporariorum were collected from infested rose plants and reared on rose. Each rose plant with one-year old was infested via 200 different stages of the whitefly. Fourteen days after infesting, compounds were sprayed on the infested plants with electrostatic atomizer backpack sprayer. Before spraying, plots were separated by plastic. Whitefly different stages from behind of three leaflets that separated from 15, 20 and 25 cm tip of plant were counted under a stereomicroscope (10 X one day before and seven days after treatment. The effect of oils and common insecticide on whitefly mortality rate (MR was performed in completely randomized

Diferentes cores de armadilhas adesivas na cultura da alface hidropônica

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Regina da Silva Borba

2014-07-01

Full Text Available O trabalho teve como objetivo avaliar qual a cor mais atrativa para os insetos-praga mosca-minadora (Liriomyza trifolii e tripes (Thrips tabaci. O experimento foi desenvolvido na empresa BioPlanta Hidroponia situada em Ivoti/RS, no período de 07/02/2012 a 03/04/2012, na cultura da alface, variedade Mouse, cultivada em ambiente protegido. Foram confeccionadas em cartelas plásticas de 10 x 15 cm, armadilhas nas cores amarela, branco, azul e verde, tendo sua superfície coberta por cola entomológica. Foram dispostas 12 repetições aleatórias de cada cor, sendo que cada mesa de cultivo hidropônico recebeu quatro cartelas de cores distintas. Foi feita a contagem dos insetos coletados semanalmente durante 9 semanas e os dados analisados pelo Programa Winstat 2.0 e as médias comparadas pelo Teste de Duncan, em nível de 5% de probabilidade de erro. As armadilhas de coloração amarela se mostraram mais atrativas para L. trifolii, enquanto a coloração azul se mostrou mais atrativa para T. tabaci.

Species of thrips (Insecta, Thysanoptera in two strawberry production systems in Rio Grande do Sul State, Brazil

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Silvia M. J. Pinent

2011-09-01

Full Text Available Species of thrips (Insecta, Thysanoptera in two strawberry production systems in Rio Grande do Sul, Brazil. Thrips are tiny insects responsible for the reduction of strawberry fruit quality. The work aimed to record and quantify the thysanopterofauna present in two strawberry production systems, low tunnel and semi-hydroponic. Leaves, flowers and fruits were collected weekly, from July 2005 to December 2006 in Caxias do Sul and Bom Princípio municipalities, RS. A total of 664 individuals were collected, representing two families, four genus and 10 species: Frankliniella occidentalis (Pergande, 1895, F. schultzei (Trybom, 1910, F. rodeos Moulton, 1933, F. simplex (Priesner, 1924, F. williamsi (Hood, 1915, F. gemina (Bagnall, 1919, Frankliniella sp., Thrips tabaci (Lindeman, 1888, Thrips tabaci (Lindeman, 1888, Caliothrips fasciatus (Pergande 1895 from Thripidae and Heterothrips sp. from Heterothripidae. Frankliniella occidentalis represented 89.7% of the samples with 95.8% of the species collected in flowers, 3.9% in fruits and 0.8% in leaves. The results show that flowers are the most important food resource for these insects on strawberry plants. Frankliniella rodeos, F. simplex, F. williamsi, C. fasciatus, and Heterothrips sp. are new records on strawberry for Brazil.

Induced plant resistance as a pest management tactic on piercing sucking insects of sesame crop

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M. F. Mahmoud

2013-09-01

Full Text Available Sesame, Sesamum indicum L. is the most oil seed crop of the world and also a major oil seed crop of Egypt. One of the major constraints in its production the damage caused by insect pests, particularly sucking insects which suck the cell sap from leaves, flowers and capsules. Impact of three levels of potassin-F, salicylic acid and combination between them on reduction infestation of Stink bug Nezara viridula L., Mirid bug Creontiades sp., Green peach aphid Myzus persicae (Sulzer, Leafhopper Empoasca lybica de Berg and Whitefly Bemisia tabaci (Gennadius of sesame crop cultivar Shandawil 3 was carried out during 2010-2011 crop season at Experimental farm, Faculty of Agriculture, Suez Canal University, Ismailia, Egypt. Also, the impacts of potassin-F and salicylic acid on yield production of sesame were studied. Results indicated that percent of reduction of infestation by N. viridula, M. persicae, Creontiades sp., E. lybicae, B. tabaci and phyllody disease were significantly higher at Level 2 (Potassin-F= 2.5 cm/l, Salicylic acid= 0.001 M and Potassin + Salicylic= 2.5 cm/l + 0.001 M and consequently higher seed yield per plant were obtained.

Thrips Species (Thysanoptera thripidae more common in cut flower greenhouse in Bogotá plateau Especies de trips (Thysanoptera:Thripidae mas comunes en invernaderos de flores de la sabana de Bogotá

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Corredor Dario

1993-12-01

Full Text Available We report sorne species found in and around greenhouses at the Bogotá plateau, whith keys and drawings to make an easier identification. Three genera were found: Taeniothrips, Thrips and
FrankDniella; this last genus has the highest number of species found inthe greenhouses. A key to identify F. occidentalis, F. auripes, F.panamensís, F. minuta, F. colombiana, Taeniothrips simplex and thrips tabaci, and a list of hosts for each species in and out of the greenhouses are presented.Se registran algunas especies de trips hallados dentro y alrededor de invernaderos en la sabana de Bogotá, se proponen claves y esquemas para facilitar su determinación. Se encontraron tres géneros a saber: Taeniothrips, Thrips y Frank#niella; este último género presenta el mayor número de especies en los invernaderos de la Sabana de Bogotá. Se propone una clave para las especies de F. occidentaKs, F.
auripes, F. panamensis, F. minuta, F. colombiana, Taeniothrips simplex y Thrips tabaci. También, se presenta una lista de plantas hospedantes para cada especie de trips, dentro y fuera de invernaderos.

Synergistic Effects of Agronet Covers and Companion Cropping on Reducing Whitefly Infestation and Improving Yield of Open Field-Grown Tomatoes

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Stella Mutisya

2016-09-01

Full Text Available Tomatoes (Lycopersicon esculentum Mill are one of the biggest vegetable crops in the world, supplying a wide range of vitamins, minerals and fibre in human diets. In the tropics, tomatoes are predominantly grown under sub-optimal conditions by subsistence farmers, with exposure to biotic and abiotic stresses in the open field. Whitefly (Bemisia tabaci Gennadius is one of the major pests of the tomato, potentially causing up to 100% yield loss. To control whitefly, most growers indiscriminately use synthetic insecticides which negatively impact the environment, humans, and other natural pest management systems, while also increasing cost of production. This study sought to investigate the effectiveness of agronet covers and companion planting with aromatic basil (Ocimum basilicum L. as an alternative management strategy for whitefly in tomatoes and to evaluate the use of these treatments ontomato growth and yield. Two trials were conducted at the Horticulture Research and Training Field, Egerton University, Njoro, Kenya. Treatments comprised a combination of two factors, (1 growing environment (agronet and no agronet and (2 companion planting with a row of basil surrounding tomato plants, a row of basil in between adjacent rows of tomato, no companion planting. Agronet covers and companion cropping with a row of basil planted between adjacent tomato rows significantly lowered B. tabaci infestation in tomatoes by 68.7%. Better tomato yields were also recorded in treatments where the two treatments were used in combination. Higher yield (13.75 t/ha was obtained from tomatoes grown under agronet cover with a basil row planted in between adjacent rows of the tomato crop compared to 5.9 t/ha in the control. Non-marketable yield was also lowered to5.9 t/ha compared to 9.8 t/ha in the control following the use of the two treatments in combination. The results of this study demonstrate the potential viability of using companion cropping and agronet

Whitefly attraction to rosemary (Rosmarinus officinialis L. is associated with volatile composition and quantity.

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Dganit Sadeh

Full Text Available Whitefly (Bemisia tabaci is an important insect pest, causing severe damage to agricultural crops. The pest was recorded in a commercial rosemary (Rosmarinus officinalis, Lamiaceae field, colonizing rosemary variety (var. '2', but not '11'. A series of field and controlled laboratory choice bioassays confirmed the observed phenomenon. Mature potted plants of the two varieties were randomly organized in a lemon verbena (Lippia citrodora and lemon grass (Cymbopogon spp. fields. Seven days later var. '2' was significantly more colonized by whiteflies than var. '11'. Under lab conditions, whiteflies were significantly more attracted to var. '2' plantlets than to var. '11' following choice bioassays. Furthermore, cotton plants dipped in an essential oil emulsion of var. '2' had significantly greater colonization than cotton plants dipped in the essential oil emulsion of var. '11'. Similar results were obtained in 'plant-plant', 'plant-no plant' as well as, 'essential oil-essential oil' choice bioassay designs. Analyses of the essential oils of the two varieties identified a set of common and unique volatiles in each variety. Among these volatiles were β-caryophyllene and limonene, two compounds known to be associated with plant-insect interactions. The attraction of B. tabaci to pure (>95% β-caryophyllene and limonene using a range of concentrations was examined in vitro by choice bioassays. The compounds were attractive to the insect at moderate concentration, but not at the lowest or highest concentrations used, where the insect was not attracted or repelled, respectively. Limonene attracted the insects at rates that were 10-fold lower than β-caryophyllene. The results emphasized the role of host plant volatiles in shaping the structure of B. tabaci populations in nature and in agricultural systems, and provided insights into the factors that contribute to the development of insect populations with unique characteristics. The results could also

Controle de mosca-branca com extratos vegetais, em tomateiro cultivado em casa-de-vegetação Use of plant extracts on whitefly control in tomato grown in greenhouse

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Edson LL Baldin

2007-12-01

Full Text Available Visando buscar métodos alternativos no controle da mosca-branca Bemisia tabaci (Gennadius biótipo B em tomateiro, foram realizados testes de atratividade e preferência para oviposição em casa-de-vegetação, utilizando-se quatorze extratos aquosos a 3% (peso/volume. Os extratos foram preparados com partes de Azadirachta indica, Trichilia pallida,Chenopodium ambrosioides,Piper nigrum,Melia azedarach,Ruta graveolens,Ricinus communis,Mentha pulegium,Tagetes erecta,Eucalyptus citriodora,Cymbopogon nardus e Coriandrum sativum. Numa segunda etapa, os extratos mais eficientes em casa-de-vegetação foram observados em laboratório, a fim de avaliar o possível efeito sistêmico dos mesmos sobre ninfas da mosca-branca. Constatou-se que as plantas de tomateiro pulverizadas com extratos à base de folhas de M. pulegium e folhas e sementes de A. indica foram menos atrativas aos adultos do inseto. Plantas pulverizadas com extratos de folhas de A. indica e folhas + ramos de R. communis mostraram efeitos deterrentes à oviposição do inseto, reduzindo o número de ovos; em contrapartida, o extrato à base de folhas de C. nardus estimulou a oviposição da mosca-branca sobre as plantas. O uso dos extratos por via sistêmica não afetou o período de desenvolvimento (ovo-adulto da mosca-branca; entretanto, a presença de extratos de sementes e folhas de A. indica e de folhas de M. pulegium provocou aumento significativo na mortalidade de ninfas de B. tabaci biótipo B.Looking for alternative methods of control to silverleaf whitefly Bemisia tabaci (Gennadius biotype B in tomato, attractiveness and oviposition preference tests were accomplished in greenhouse using fourteen aqueous extracts at 3% (weight/volume. The extracts were prepared with parts from Azadirachta indica,Trichilia pallida,Chenopodium ambrosioides,Piper nigrum,Melia azedarach,Ruta graveolens,Ricinus communis,Mentha pulegium,Tagetes erecta,Eucalyptus citriodora, Cymbopogon nardus and

Insect symbiosis: derivation of yeast-like endosymbionts within an entomopathogenic filamentous lineage.

Science.gov (United States)

Suh, S O; Noda, H; Blackwell, M

2001-06-01

Yeast-like endosymbionts (YLSs) of insects often are restricted to specific hosts and are essential to the host's survival. For example, in planthoppers (Homoptera: Delphacidae), endosymbionts function in sterol utilization and nitrogen recycling for the hosts. Our study, designed to investigate evolutionary changes in the YLS lineage involved in the planthopper association, strongly suggests an origin of the YLSs from within the filamentous ascomycetes (Euascomycetes), not the true yeasts (Saccharomycetes), as their morphology might indicate. During divergence of the planthopper YLSs, dramatic changes would have occurred in the insect-fungus interaction and the fungal morphology that have previously been undescribed in filamentous ascomycetes. Phylogenetic trees were based on individual and combined data sets of 2.6 kb of the nuclear small- and large-subunit ribosomal RNA genes for YLSs from three rice planthoppers (Laodelphax striatellus, Nilaparvata lugens, and Sogatella furcifera) compared with 56 other fungi. Parsimony analysis placed the planthopper YLSs within Cordyceps (Euascomycetes: Hypocreales: Clavicipitaceae), a genus of filamentous insects and a few fungal pathogenic ascomycetes. Another YLS species restricted to the aphid Hamiltonaphis styraci (Homoptera: Aphididae) was a sister taxon to the planthopper YLSS: Filamentous insect pathogens (Metarhizium and Beauveria) specific to the same species of insect hosts as the YLSs also formed lineages within the Clavicipitaceae, but these were distinct from the clade comprising YLS species. Trees constrained to include the YLSs in families of the Hypocreales other than the Clavicipitaceae were rejected by the Kishino-Hasegawa test. In addition, the results of this study support a hypothesis of two independent origins of insect-associated YLSs from among filamentous ascomycetes: the planthopper YLSs in the Clavicipitaceae and the YLSs associated with anobiid beetles (Symbiotaphrina species). Several lineages of

A novel synthetic quantification standard including virus and internal report targets: application for the detection and quantification of emerging begomoviruses on tomato

OpenAIRE

Péréfarres, Frédéric; Hoareau, Murielle; Chiroleu, Frédéric; Reynaud, Bernard; Dintinger, Jacques; Lett, Jean-Michel

2011-01-01

Abstract Background Begomovirus is a genus of phytopathogenic single-stranded DNA viruses, transmitted by the whitefly Bemisia tabaci. This genus includes emerging and economically significant viruses such as those associated with Tomato Yellow Leaf Curl Disease, for which diagnostic tools are needed to prevent dispersion and new introductions. Five real-time PCRs with an internal tomato reporter gene were developed for accurate detection and quantification of monopartite begomoviruses, inclu...

Diversity and Phylogenetic Analyses of Bacterial Symbionts in Three Whitefly Species from Southeast Europe

OpenAIRE

Skaljac, Marisa; Kanakala, Surapathrudu; Zanic, Katja; Puizina, Jasna; Lepen Pleic, Ivana; Ghanim, Murad

2017-01-01

Bemisia tabaci (Gennadius), Trialeurodes vaporariorum (Westwood), and Siphoninus phillyreae (Haliday) are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts dete...

Respon Fungsional Menochilus sexmaculatus Fabricius terhadap Aphis Gossypii Glover

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F. X. Wagiman

1996-12-01

Full Text Available Laboratory and field-cage experiments were conducted at the Universiti Pertanian Malaysia. Objective of the study was to determine the functional response of Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae predating on chilli aphid Aphis gossypii Glover (Homoptera: Aphididae. The larvae and adults of the predaceous coccinellid exhibited the Hulling's Type II functional response. A first instar of the coccinellid predating on single first instar of the aphid within 24.6 minutes in the laboratory and 16.8 minutes in the field. While a fourth instar and an adult of the coccinellid predating on single fourth instar of the aphid within 4.2 and 1.5 minutes respectively.

A case to study population dynamics of bemisia tabaci and thrips tabaci on bt and non-bt cotton genotypes

International Nuclear Information System (INIS)

Akram, M.; Hussain, M.; Ahmed, S.; Hafeez, F.; Farooq, M.; Arshad, M.

2013-01-01

Studies were conducted to investigate the performance of eight bt and five non-bt cotton genotypes against whitefly and thrips and impact of abiotic factors on the population fluctuation of these sucking pests, at cotton research station, multan, during 2010 and 2011. The results exhibited that bt genotypes found more susceptible host for the whitefly and thirps than non-bt genotypes, during the course of years of study. Among bt genotypes, maximum and minimum temperature showed significant and positive effect on whitefly population whereas relative humidity exerted negative effect during 2010. During 2011, the effect of all the factors was non significant. On cumulative basis, there was positive correlation between population of whitefly and minimum temperature. But in case of non-bt, it has negative with maximum temperature whereas relative humidity had a positive effect on whitefly population. similar trend was observed for thrips population on bt varieties during both years but on non-bt varieties only minimum temperature exerted strong positive impact on thrips population. Hierarchical regression models for whitefly and thrips revealed that minimum temperature was the most important factor (Bt and non-Bt varieties). Maximum temperature was the major contributing factor for whitefly fluctuation on bt varieties during 2010. (author)

Distributional patterns and possible origin of leafhoppers (Homoptera, Cicadellidae

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Mervin W. Nielson

2000-03-01

Full Text Available The zoogeographical distribution of 42 cicadellid subfamilies and their assigned tribes and genera is compiled with distributional maps and proposed dispersal pathways of genera that are shared interzoogeographically. Possible origin of the subfamilies and tribes is proposed in an ancestral context from which the more modern extant groups evolved whereas origin of genera is in a more modern context. Notwithstanding their complex biogeography, the distributional data of the higher groups indicate that all of the cosmopolitan and near cosmopolitan subfamilies arose during early Cretaceous or possibly the late Jurassic period (140-116 m.y.a. when continental drift was in its early stages. Nearly all of the New World and some Old World subfamilies are considered of more recent origin (late Cretaceous-Tertiary. Ninety percent of the known genera (2,126 are endemic to their respective zoogeographical region and subregion, thus indicating relatively high host specificity and low rate of dispersal. The majority (76% of known extant genera are pantropical in origin, suggesting early or possible Gondwanaland origin of their ancestors. Dispersal pathways of genera shared by more than one zoogeographical region were generally south to north (Neotropical/Nearctic, Oriental/Palaearctic or west to east (Palaearctic/Nearctic, Oriental/Australian, from regions of high diversity to regions of low diversity and from warmer climates to cooler climates. The most diverse and richest leafhopper fauna are present in the Neotropical and Ethiopian regions although taxal affinities between them are poorest. The most depauperate fauna are in the Nearctic region and in Australia, reflecting the impact of isolating and ecological factors on distribution and radiation. Ecological barriers were more evident between the Ethiopian and Oriental fauna than between any other zoogeographical combination. Taxal affinities appeared to be correlated with close continental proximities. Vicariance (physical was the principal event that appealed to explain the distribution of many subfamilies and tribes whereas dispersal accounted for distribution of the majority of interzoogeographical genera.

Appearance of Neotoxoptera formosana (Homoptera: Aphididae) in The Netherlands

NARCIS (Netherlands)

Piron, P.G.M.

2010-01-01

Neotoxoptera formosana (Takahashi) is a pest of wild and cultivated Allium species, but never iwht disastrous consequences. In 1984, N. formosana was found in France. This was the first finding in Europe. Since then, N. formosana has been observed also in other European countries. The first record

Calling songs of some South African cicadas (Homoptera: Cicadidae)

African Journals Online (AJOL)

1987-07-13

Jul 13, 1987 ... Figure 11 Posture of male cicadas during calling song, illustrated by a specimen ... parameters of the smaller samples falls within that of the largest conspecific ... under the control of the neuromuscular system (Pringle. 1954b).

Aspects of the ecology of spittlebugs (Homoptera: Cercopidae) in ...

African Journals Online (AJOL)

Species type and pattern of distribution of spittlebugs was studied from 6th March to 15th December 2009 within the University of Nigeria, Nsukka campus. Three spittlebug species namely, Deois flavopicta, Aphrophora saratogensis and Philaenus spumarius were identified within the University campus. Whereas A.

Shallot aphids, Myzus ascalonicus, in strawberry

DEFF Research Database (Denmark)

Enkegaard, Annie; Sigsgaard, Lene; Kristensen, Kristian

2013-01-01

The parasitization capacity of 3 parasitoids and the predation capacity of 3 predators towards the shallot aphid, Myzus ascalonicus Doncaster (Homoptera: Aphididae), on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae) cv. Honeoye, were examined in laboratory experiments. In Petri dish...... other parasitoid-induced causes. However, the host feeding rate was reduced to only 1.2 ± 0.8%, and no significant parasitization mortality was observed on strawberry plants, suggesting that host plants interfered with A. abdominalis activity. This parasitoid does not, therefore, seem to be suited...... to either inoculative or inundative biocontrol of shallot aphids in strawberry. The three predators studied were the green lacewing, Chrysoperla carnea Steph. (Neuroptera: Chrysopi-dae), the two-spotted lady beetle, Adalia bipunctata L. (Coleoptera: Coccinellidae), and the gall midge Aphidoletes aphidimyza...

Food habits of introduced rodents in high-elevation shrubland of Haleakala National Park, Maui, Hawai'i

Science.gov (United States)

Cole, F. Russell; Loope, Lloyd L.; Medeiros, Arthur C.; Howe, Cameron E.; Anderson, Laurel J.

2000-01-01

Mus musculus and Rattus rattus are ubiquitous consumers in the high-elevation shrubland of Haleakala National Park. Food habits of these two rodent species were determined from stomach samples obtained by snaptrapping along transects located at four different elevations during November 1984 and February, May, and August 1985. Mus musculus fed primarily on fruits, grass seeds, and arthropods. Rattus rattus ate various fruits, dicot leaves, and arthropods. Arthropods, many of which are endemic, were taken frequently by Mus musculus throughout the year at the highest elevation where plant food resources were scarce. Araneida, Lepidoptera (primarily larvae), Coleoptera, and Homoptera were the main arthropod taxa taken. These rodents, particularly Mus musculus, exert strong predation pressure on populations of arthropod species, including locally endemic species on upper Haleakala Volcano.

Plant-mediated horizontal transmission of Rickettsia endosymbiont between different whitefly species.

Science.gov (United States)

Li, Yi-Han; Ahmed, Muhammad Z; Li, Shao-Jian; Lv, Ning; Shi, Pei-Qiong; Chen, Xiao-Sheng; Qiu, Bao-Li

2017-12-01

A growing number of studies have revealed the presence of closely related endosymbionts in phylogenetically distant arthropods, indicating horizontal transmission of these bacteria. Here we investigated the interspecific horizontal transmission of Rickettsia between two globally invasive whitefly species, Bemisia tabaci MEAM1 and B. tabaci MED, via cotton plants. We found both scattered and confined distribution patterns of Rickettsia in these whiteflies. After entering cotton leaves, Rickettsia was restricted to the leaf phloem vessels and could be taken up by both species of the Rickettsia-free whitefly adults, but only the scattered pattern was observed in the recipient whiteflies. Both the relative quantity of Rickettsia and the efficiency of transmitting Rickettsia into cotton leaves were significantly higher in MEAM1 females than in MED females. The retention time of Rickettsia transmitted from MEAM1 into cotton leaves was at least 5 days longer than that of MED. Phylogenetic analysis based on 16S rRNA and gltA genes confirmed that the Rickettsia extracted from the donor MEAM1, the cotton leaves, the recipient MEAM1 and the recipient MED were all identical. We conclude that cotton plants can mediate horizontal transmission of Rickettsia between different insect species, and that the transmission dynamics of Rickettsia vary with different host whitefly species. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Novos acessos de tomateiro resistentes à mosca-branca biótipo B New accessions of tomato resistant to whitefly biotype B

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Maria Elisa de Sena Fernandes

2009-11-01

Full Text Available O objetivo deste trabalho foi selecionar novas fontes de resistência a Bemisia tabaci biótipo B, entre 34 acessos de tomateiro (Lycopersicon esculentum, do Banco de Germoplasma de Hortaliças da UFV. Avaliaram-se os números de adultos, ovos e ninfas por planta, além da densidade de tricomas. Detectaram-se diferenças entre os acessos nas variáveis avaliadas. Os acessos BGH-166, BGH-616, BGH-850, BGH-990, BGH-2102 e BGH-2125 apresentaram menor número de adultos, ovos e ninfas por planta e tiveram menor densidade de tricomas. A resistência dos acessos de tomate à mosca-branca foi associada a uma menor densidade de tricomas.The objective of this work was to evaluate resistance to Bemisia tabaci biotype B in 34 tomato (Lycopersicon esculentum accessions from the Banco de Germoplasma de Hortaliças of UFV. The number of adults, eggs and nymphs per plant besides of trichome density were evaluated. Differences between accessions were found for the evaluated variables. Accessions BGH-166, BGH-616, BGH-850, BGH-990, BGH-2102 and BGH-2125 presented less infestation of adults, eggs and nymphs per plant and showed lower trichome density. The resistance of these tomato accessions to whitefly was associated to a lower trichome density.

A simple, rapid and inexpensive method for localization of Tomato yellow leaf curl virus and Potato leafroll virus in plant and insect vectors.

Science.gov (United States)

Ghanim, Murad; Brumin, Marina; Popovski, Smadar

2009-08-01

A simple, rapid, inexpensive method for the localization of virus transcripts in plant and insect vector tissues is reported here. The method based on fluorescent in situ hybridization using short DNA oligonucleotides complementary to an RNA segment representing a virus transcript in the infected plant or insect vector. The DNA probe harbors a fluorescent molecule at its 5' or 3' ends. The protocol: simple fixation, hybridization, minimal washing and confocal microscopy, provides a highly specific signal. The reliability of the protocol was tested by localizing two phloem-limited plant virus transcripts in infected plants and insect tissues: Tomato yellow leaf curl virus (TYLCV) (Begomovirus: Geminiviridae), exclusively transmitted by the whitefly Bemisia tabaci (Gennadius) in a circulative non-propagative manner, and Potato leafroll virus (Polerovirus: Luteoviridae), similarly transmitted by the aphid Myzus persicae (Sulzer). Transcripts for both viruses were localized specifically to the phloem sieve elements of infected plants, while negative controls showed no signal. TYLCV transcripts were also localized to the digestive tract of B. tabaci, confirming TYLCV route of transmission. Compared to previous methods for localizing virus transcripts in plant and insect tissues that include complex steps for in-vitro probe preparation or antibody raising, tissue fixation, block preparation, sectioning and hybridization, the method described below provides very reliable, convincing, background-free results with much less time, effort and cost.

EFEITO ANTIBIÓTICO DO PRÓPOLIS SOBRE BACTÉRIAS FITOPATOGÊNICAS

OpenAIRE

BIANCHINI, L.; BEDENDO, I.P.

1998-01-01

O efeito antibiótico de extrato aquoso de própolis, em várias concentrações, foi avaliado para cinco espécies de bactérias fitopatogênicas. Agrobacterium tumefaciens, Clavibacter michiganensis subsp. michiganensis e Xanthomonas axonopodis pv. phaseoli foram completamente inibidas em meio de cultura contendo 10% de extrato de própolis. Erwinia chrysanthemi foi parcialmente inibida, enquanto Pseudomonas syringae pv. tabaci se mostrou insensível ao extrato, desenvolvendo colônias idênticas àquel...

A synopsis of the tribe Micrutalini Haupt (Homoptera, Membracidae, Smiliinae

Directory of Open Access Journals (Sweden)

Albino M. Sakakibara

1999-01-01

Full Text Available The tribe Micrutalini and its two genera, Trachytalis Fowler and Micrutalis Fowler, are redescribed. The following species are treated and, in some cases, nomenclatura! changes introduced: Trachytalis isabellina Fowler, 1895; T. distinguenda Fowler, 1895; T. retrofasciata (Lethierry, 1890, comb.n.; Micrutalis alrovena Goding, 1930; M. balteata (Fairmaire, 1846 = Aculalis lucidus Buckton, 1902, syn.n.; M. bella Goding, 1929; M. biguttula (Fairmaire, 1846, comb.n.; M. binaria (Fairmaire, 1846 = Acutalis flavivenlris Lethierry, 1890, syn.n.; M. callan-gensis Goding, 1930; M. calva (Say, 1830; M. discalis (Walker, 1858; M. dorsalis (Fitch, 1851; M. dubia Fowler, 1895 = M. zeteki Goding, 1928, syn.n.; M. flava Goding, 1929; M. flavozonala (Fairmaire, 1846, comb.n. = Acutalis geniculata Stál, 1862, syn.n. = Acutalis modesta Stál, 1862, syn.n.; M. godfreyi Sakakibara, 1976; M. incerla Sakakibara, 1976; M. lata Goding, 1930; M. litlerala (Fairmaire, 1846, comb.n.;M lugubrina(Stál, 1862;M malleiferaFovj]er, 1895 = M binariamutabilis Fowler, 1895, syn.n.; M. minutus Buckton, 1902; M. nigrolineata (Stál, 1864; M. nigromarginata Funkhouser, 1940; M. notalipennis Fowler, 1895; M. occidentalis (Goding, 1893; M. pollens Fowler, 1895; M. parva (Goding, 1893; M. plagíala (Stál, l&62 = AcutalisvariabiIisBerg, 1879,syn.n. =M. chapadensisGoding, 1930,syn.n.; M. punctifera (Walker, 1858; M. semialba (Stál, 1862; M. stipulipennis Buckton, 1902; M. tau Goding, 1930; M. trifurcala Goding, 1893; M. tripunctata (Fairmaire, 1846 = Acutalis moesta Stál, 1859, syn.n. = M. tartaredoides Goding, 1930, syn.n.. New species: Micrutalis diminuta sp.n. (Ecuador, Pichincha; Micrutalis divisa sp.n. (Brazil, Mato Grosso; Micrutalis henki sp.n. (Panama, Canal Zone; Micrutalis infúscala sp.n. (Venezuela, Portuguesa; Micrutalis margínala sp.n. (Brazil, Mato Grosso; Micrutalis meridana sp.n. (Venezuela, Mérida; Micrutalis mucuya sp.n. (Venezuela, Mérida; Micrutalis robustula sp.n. (Venezuela, Caracas; M. seminigra sp.n. (Brazil, Paraná; Micrutalis turriba sp.n. (Costa Rica, Turrialba. Lectotypes are designated for: Acutalis balteata Fairmaire, 1846, Aculalis binaria Fairmaire, 1846, Acutalis flavozonala Fairmaire, 1846, una Acutalis tripunctata Fairmaire, 1846. New taxonomic position: Micrutalis melanogramma (Petty, 1833 is transferred to Melu-sinella Metcalf, 1952 (Ceresini - Melusinella melanogramma (Petty, 1833, comb.n. = Melusinella nervosa (Fairmaire, 1846, syn.n.. Species incertae sedis: Tragopa ephippium Burmeister, 1836.

Particle film affects black pecan aphid (Homoptera: Aphididae) on pecan.

Science.gov (United States)

Cottrell, Ted E; Wood, Bruce W; Reilly, Charles C

2002-08-01

Three species of aphids attack pecan foliage, Carya illinoensis (Wang.) K. Koch, and cause economic damage. We tested a kaolin-based particle film against one of these aphid species, black pecan aphid, Melanocallis caryaefoliae (Davis). Effect of particle film on host selection, adult mortality, and production of nymphs by M. caryaefoliae was tested on seedling pecans in the laboratory. Fewer M. caryaefoliae adults selected treated foliage compared with untreated foliage. A higher percentage of adults that did select treated foliage were recovered from upper leaf surfaces compared with the percentage of adults recovered from upper leaf surfaces of untreated leaves. Observations with a microscope revealed an accumulation of particle film on aphid body parts, especially on tarsi, and strongly suggests that aphid mobility was restricted. Adult mortality was higher on treated foliage and led to an overall decrease in production of nymphs on those seedlings. In addition, we measured spectral properties of treated seedling pecan foliage. Light reflectance by treated foliage was increased and absorptance decreased compared with control foliage whereas transmittance of light through control and particle film-treated leaves was similar. We did not detect any phytotoxic effect on pecan due to application of particle film.

Food habits of Nyctinomops macrotis at a maternity roost in New Mexico, as indicated by analysis of guano

Science.gov (United States)

Sparks, D.W.; Valdez, E.W.

2003-01-01

We examined 56 fecal pellets from under a maternity colony of big free-tailed bats (Nyctinomops macrotis) in the Jemez Mountains of northern New Mexico. The most important food items, listed in order of decreasing percent volume, were Cicadellidae, leafhoppers (26.7% volume, 58.9% frequency); Ichneumonidae, Ichneumon wasps (19.3% volume, 35.7% frequency); and Lepidoptera, moths (17.2% volume, 82.1% frequency). Overall, the most important orders as prey consumed, listed by decreasing percent volume, were Homoptera (27.6% volume, 62.5% frequency), Hymenoptera (19.5% volume, 37.5% frequency), Lepidoptera (17.2% volume, 82.1% frequency), Hemiptera (11.7% volume, 37.5% frequency), and Diptera (10.6% volume, 50.0% frequency). Our study documents an unusually varied diet, as previous studies indicated that these bats fed almost exclusively on moths.

Dicty_cDB: Contig-U15678-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available nating seedlings, TAMU Sola... 52 6e-10 3 ( DY336852 ) OB_SEa04P11.r OB_SEa Ocimum basil...efly Bemisia tabaci... 50 6e-10 2 ( T34713 ) EST73889 Human Bone Homo sapiens cDNA 5' end simi...qyiyiffiyiffffpklyif*kiilhpstqkkkkkkkkniisqhtv fcisi*ssp*nyffykkkik*ivfvfvliivifffpllnk*kkksffffliiyivi...qmyqphfkciliqaqtlte*lveqvmiqitf*lilq *rvklsiveplkfsinslinvlilvstlqvnkmqiplvevlkmf*dpskvvhnnhhhkyq nhnhnnhhnh... ... 60 5e-14 4 ( GE464933 ) 294762759 Nasonia vitripennis Adult Female Nasoni... 70 5e-14 2 ( BU819448 ) UA43BPG03 Populus trem

Revisão do gênero Potnia Stål (Homoptera, Membracidae, Membracinae, Hoplophorionini Revision of the genus Potnia Stål (Homoptera, Membracidae, Membracinae, Hoplophorionini

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Antônio J Creão-Duarte

1996-01-01

Full Text Available Fifteen species of Potnia Stål, 1866 are presented with descriptions, illustrations and a key for identification. The following nomenclatural changes are introduced: P. knightae sp.n. (from Guiana, P. miracyae sp.n. (from Costa Rica, P. diringshofeni sp.n. (from Brasil, P. webbi sp.n. (from Brazil, P. turrialbensis sp.n. (from Costa Rica, P. pinheiroi sp.n. (from Brazil, P. tapuruquarensis sp.n. (from Brasil, P. cornigera sp.n. (from Brazil and P. inca sp.n. (from Peru. Potnia venosa (Germar, 1821 = Aconophora nigrivittata Walker, 1851, syn.n. = Potnia perobtusa Fowler, 1894, syn.n.. Potnia brevicornis Fowler, 1894, sp. reval. = Potnia brunneifrontis Funkhouser, 1943, syn.n. = Potnia maculata Funkhouser, 1943, syn.n.. Potnia jacula (Fabricius, 1803 = Potnia orthosoma Fonseca & Diringshofen, 1974, syn.n.

Ant tending influences soldier production in a social aphid.

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Shingleton, A W; Foster, W A

2000-09-22

The aphid Pseudoregma sundanica (Van der Goot) (Homoptera: Aphididae) has two defence strategies. It is obligatorily tended by various species of ant and also produces sterile soldiers. We investigated how they allocate their investment in these two strategies. We measured the size, number of soldiers, number and species of tending ant, and number and species of predators in P. sundanica populations. We found that the level of ant tending correlated negatively with soldier investment in P. sundanica. The species of tending ant also influenced soldier investment. We excluded ants from aphid populations and recorded changes in population size and structure over four weeks. Ant exclusion led to population decline and extinction. At the same time, surviving populations showed a significant increase in soldier investment. The data demonstrate that social aphids can adjust their investment in soldiers in direct response to environmental change.

[Anthropoentomophagic biodiversity of the Zongolica region, Veracruz, Mexico].

Science.gov (United States)

Ramos-Elorduy, Julieta; Landero-Torres, Ivonne; Murguía-González, Joaquín; Pino, José M M

2008-03-01

Anthropoentomophagic biodiversity of the Zongolica region, Veracruz, Mexico. During two and a half years (2003-2005) we recorded the insect species used as food at Zongolica, Veracruz State, Mexico. Interviews were made among people (200) of this municipality to know which insects they consumed. The total of registered species was 57 (Orthoptera, Hemiptera, Homoptera, Megaloptera, Coleoptera, Lepidoptera and Hymenoptera). The Orthoptera was the most frequently ingested. Twenty-four of these species were new records for edible insects of Mexico. They are eaten in immature stages or as adults, generally only roasted. Consumption is seasonal. Some species are commercialized in the "tianguis" (little town markets) and/or in the larger Zongolica market. There is a "protoculture" of three species, one cockroach (Periplaneta australasiae Fabricius) and two moths (Latebraria amphipyroides Guenée and Arsenura armida armida Cramer). In Zongolica, anthropoentomophagy is an ancestral habit.

Secondary metabolites from the endophytic fungus Talaromyces pinophilus.

Science.gov (United States)

Vinale, F; Nicoletti, R; Lacatena, F; Marra, R; Sacco, A; Lombardi, N; d'Errico, G; Digilio, M C; Lorito, M; Woo, S L

2017-08-01

Endophytic fungi have a great influence on plant health and growth, and are an important source of bioactive natural compounds. Organic extracts obtained from the culture filtrate of an endophytic strain of Talaromyces pinophilus isolated from strawberry tree (Arbutus unedo) were studied. Metabolomic analysis revealed the presence of three bioactive metabolites, the siderophore ferrirubin, the platelet-aggregation inhibitor herquline B and the antibiotic 3-O-methylfunicone. The latter was the major metabolite produced by this strain and displayed toxic effects against the pea aphid Acyrthosiphon pisum (Homoptera Aphidiidae). This toxicity represents an additional indication that the widespread endophytic occurrence of T. pinophilus may be related to a possible role in defensive mutualism. Moreover, the toxic activity on aphids could promote further study on 3-O-methylfunicone, or its derivatives, as an alternative to synthetic chemicals in agriculture.

Evaluation of botanicals for onion thrips, Thrips tabaci Lindeman ...

African Journals Online (AJOL)

Bheema

the highest effect in reducing thrips pest population in year one, though was on par with that of dimethoate, did ... From among the botanicals tested, tree tobacco had the best ... Moreover, as most smallholder famers may not afford the ever.

Responses of Russian Wheat Aphid (Homoptera: Aphididae) to Aphid Alarm Pheromone

OpenAIRE

Shah, P. A.; Pickett, J. A.; Vandenberg, J. D.

2017-01-01

In a series of laboratory tests, Russian wheat aphids, Diuraphis noxia (Mordvilko), responded to synthetic aphid alarm pheromone, (E)-β-farnesene, by removing stylets and leaving feeding sites or by crawling out of test arenas. Late instars and adults were more responsive than early instars. In dose-response assays, EC50 estimates ranged from 0.94 to 8.95 mg/ml among 3 experiments. In arenas, D. noxia also responded to the proximity of cornicle-damaged nymphs of either the green peach aphid, ...

Cytogenetic and taxonomic studies of some legless mealybugs (Homoptera, Coccinea, Pseudococcidae

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Ilya A. Gavrilov-Zimin

2016-11-01

Full Text Available A new monotypic genus and species, Komodesia circuliplurima gen. et sp. n., from Flores Is. (Indonesia and the new species, Antonina diversiglandulosa sp. n., from Southern Thailand are described and illustrated. Chromosomes of these species and also the ones of Antonina purpurea Signoret, 1872 and A. thaiensis Takahashi, 1942 are studied for the first time: 2n = 30, 20, 12 and 22+Bs correspondingly; the male embryos of all four species demonstrate Lecanoid paternal heterochromatinization of one haploid set of chromosomes. The karyotypes of three widely distributed species, Antonina pretiosa Ferris, 1953, A. graminis (Maskell, 1897 and Chaetococcus bambusae (Maskell, 1893, are studied based on material from other regions in comparison with previously published data. Photographs of the karyotypes are provided for the first time for all seven species. The terminological problems connected with the identification and naming of the three scale insect genetic systems, Lecanoid, Comstockioid and Diaspidoid, are discussed.

Hemlock woolly adelgid (Homoptera: Adelgidae): stylet bundle insertion and feeding sites

Science.gov (United States)

Rebecca F. Young; Kathleen S. Shields; Graeme P. Berlyn

1995-01-01

Stylet bundle insertion site, path traveled, and feeding site were examined for the hemlock woolly adelgid, Adelges tsugae Annand, on needles from current and previous years of eastern hemlock, Tsuga canadensis Carriere. The stylet bundle is composed of 4 individual stylets--2 outer mandibular stylets and 2 inner maxillary stylets...

Biodiversidad antropoentomofágica de la región de Zongolica, Veracruz, México

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Julieta Ramos-Elorduy

2008-03-01

Full Text Available Durante dos años y medio (2003-2005 se rastrearon a los insectos que se ingieren en el área de Zongolica, Veracruz: para ello se entrevistó a la gente de ese municipio (200, para conocer cuáles especies ingerían. El total de especies registradas, ascendió a 57 distribuidas en los órdenes Orthoptera, Hemiptera, Homoptera, Megaloptera, Coleoptera, Lepidoptera e Hymenoptera, correspondiendo el mayor consumo al primer orden. De las especies registradas, 24 son nuevos registros de insectos comestibles para México. Estos se consumen tanto en estado inmaduro como en estado adulto y generalmente se ingieren asados. Hay una secuenciación estacional en el consumo de las diferentes especies y algunas de ellas (las cucarachas, la cuetla, la cuecla, los chapulines, los toritos, etc. se comercializan en los tianguis (puestos de venta callejeros informales que se realizan un día a la semana en diversos lugares del país o en el día de mercado en Zongolica. Existe el "protococultivo" de tres especies: una cucaracha (Periplaneta australasiae Fabricius y dos mariposas (Latebraria amphipyroides Guenée y Arsenura armida armida Cramer. La antropoentomofagía es un hábito ancestral en Zongolica.Anthropoentomophagic biodiversity of the Zongolica region, Veracruz, Mexico. During two and a half years (2003-2005 we recorded the insect species used as food at Zongolica, Veracruz State, Mexico. Interviews were made among people (200 of this municipality to know which insects they consumed. The total of registered species was 57 (Orthoptera, Hemiptera, Homoptera, Megaloptera, Coleoptera, Lepidoptera and Hymenoptera. The Orthoptera was the most frequently ingested. Twenty-four of these species were new records for edible insects of Mexico. They are eaten in immature stages or as adults, generally only roasted. Consumption is seasonal. Some species are commercialized in the "tianguis" (little town markets and/or in the larger Zongolica market. There is a

Aspectos biológicos y poblacionales de Nasonovia ribisnigri y Aulacorthum solani sobre lechuga

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Vasicek Araceli

2002-01-01

Full Text Available Se estimó la influencia de los cultivares Criolla Blanca, Cuatro Estaciones y Gallega, sobre la biología y los parámetros poblacionales de Nasonovia ribisnigri y Aulacorthum solani (Homoptera: Aphidoidea a 10±1ºC y HR de 90%. Los períodos ninfal, pre-reproductivo y post-reproductivo de N. ribisnigri fueron más largos sobre Cuatro Estaciones, no así el reproductivo. En A. solani el período ninfal fue más largo sobre Criolla Blanca y Cuatro Estaciones resultando el reproductivo mayor sobre Cuatro Estaciones. Las tasas intrínsecas de crecimiento natural (r m de N. ribisnigri y A. solani fueron mayores sobre Criolla Blanca y Gallega, respectivamente. De acuerdo a la especie predominante convendría utilizar Cuatro Estaciones para N. ribisnigri y Criolla Blanca para A. solani, en épocas frías.

Metcalfa pruinosa (Say (Homoptera: Auchenorrhyncha anew harmful species for entomofauna of Serbia

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Mihajlović Ljubodrag

2007-01-01

Full Text Available In the early autumn 2006, a Nonarctic species of cicadas Metcalfa pruinosa (Say (Auchenorrhyncha: Flatidae was identified in Belgrade (Košutnjak. In Europe, this species was identified for the first time in Italy in 1979. In Slovenia, it was identified in 1990 in west Istria, and in 2001 in the neighbourhood of Ljubljana. In the park forest Košutnjak (Belgrade mass occurrence of M. pruinosa was recorded in the area of about 5 ha. The larvae developed on woody species in the genera: Acer, Aesculus, Gleditchia Robinia, Ailanthus, Populus, Platanus, Prunus, Pyrus, Ulmus, Tilia, Cornus Fraxinus, Quercus and Thuja, što is konstatovano based on damages of larvae while numerous adults were found on trees and branches of the same plants.

The taxonomy and biogeography of the genus Thaumastopsaltira Kirkaldy, 1900 (Homoptera, Tibicinidae)

NARCIS (Netherlands)

Boer, de A.J.

1992-01-01

The taxonomic concept of the genus Thaumastopsaltria Kirkaldy is redefined on the basis of the shape of postclypeus and the length of the ovipositor. Tegmen venation is shown to be unreliable for this purpose. T. nana (Jacobi) does not fit this new concept and is, pending its transfer to another

EFEITO ANTIBIÓTICO DO PRÓPOLIS SOBRE BACTÉRIAS FITOPATOGÊNICAS

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L. BIANCHINI

1998-01-01

Full Text Available O efeito antibiótico de extrato aquoso de própolis, em várias concentrações, foi avaliado para cinco espécies de bactérias fitopatogênicas. Agrobacterium tumefaciens, Clavibacter michiganensis subsp. michiganensis e Xanthomonas axonopodis pv. phaseoli foram completamente inibidas em meio de cultura contendo 10% de extrato de própolis. Erwinia chrysanthemi foi parcialmente inibida, enquanto Pseudomonas syringae pv. tabaci se mostrou insensível ao extrato, desenvolvendo colônias idênticas àquelas observadas em meios livres de própolis. Concentrações menores não foram suficientes para exercer um efeito antimicrobiano desejável sobre as bactérias pertencentes a todas as espécies testadas. Resultados idênticos foram obtidos quando própolis foi incorporado ao meio antes ou após a autoclavagem, demonstrando que a substância ativa presente no extrato não é termosensível. Foi demonstrado, portanto, o uso potencial do própolis como antibiótico para o controle de bactérias fitopatogênicas.The antibiotic effect of aqueous extract of propolis was evaluated in vitro against five species of bacteria. The growth of Agrobacterium tumefaciens, Clavibacter michiganensis subsp. michiganensis and Xanthomonas axonopodis pv. phaseoli was completely inhibited in a medium containing 10% of propolis. Erwinia chrysanthemi was partially inhibited and Pseudomonas syringae pv. tabaci was not affected. Lower concentration of the aqueous extract was not effective to promote a desirable antibiotic action against all bacterial species tested. The active ingredient present in the propolis was thermostable. The potential use of the propolis to control phytopathogenic bacteria was demonstrated.

Biology of the citrus blackfly, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), in three host plants; Biologia da mosca-negra-dos-citros, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), em tres plantas hospedeiras

Energy Technology Data Exchange (ETDEWEB)

Pena, Marcia R.; Silva, Neliton M. da [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil).Lab. de Entomologia Agricola], e-mail: marciarpena@yahoo.com.br, e-mail: nmarques@ufam.edu.br; Venframim, Jose D.; Haddad, Marineia de L. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Lab. de Resistencia de Plantas e Plantas Inseticidas], e-mail: jdvendra@esalq.usp.br, e-mail: mlhaddad@esalq.usp.br; Lourencao, Andre L. [Instituto Agronomico de Campinas (IAC), SP (Brazil)], e-mail: andre@iac.sp.gov.br

2009-03-15

The citrus blackfly, Aleurocanthus woglumi Ashby, was detected in Brazil in 2001. The aim of this research was to evaluate the biology, biometry and host preference of A. woglumi in sweet orange, acid lime Tahiti and mango. Experiments were set in laboratory conditions with insects collected in rangpur lime plants in Manaus, State of Amazonas, from January to June of 2006. The following parameters were evaluated: number of spirals (ovo positions) and eggs per plant, number of eggs by spiral per plant, survival of the immature (eggs, 1st, 2nd, 3rd and 4th instars), and length and survival of the immature stage. The mean embrionary period was 15 days for the three hosts. The 4th nymph (puparium) was the longest during nymph development. Second and third instars had the highest survival. The mean length of the egg-adult cycle was 70 days for the three hosts evaluated. The eggs were laid in a spiral shape on the adaxial leaf surface. The 1st instars moved to short distances from the spiral, while the 2nd, 3rd and 4th are sessile and have bristles on the whole body. Based on the highest oviposition and the highest survival of the immature stage of the citrus blackfly in acid lime Tahiti, this plant can be considered the most suitable host to A. woglumi. (author)

BIOLOGY OF CHRYSOPA PHYLLOCHROMA WESMAEL （NEUROPTERA： CHRYSOPIDAE）. Ⅱ： INTRASPECIFIC INTERFERENCE AND SEARCHING CAPACITY

Institute of Scientific and Technical Information of China (English)

Jian-weiSu; Xiang-huiLiu; Neng-wenXiao; FengGe

2004-01-01

The present study examined intraspecific interference and searching behavior of Chrysopa phyllochroma Wesmael (Neuroptera: Chrysopidae) for Aphis gossypii Glover (Homoptera: Aphididae) nymphs under laboratory and greenhouse conditions. The results were shown as follow: 1) In four different arenas (i.e. Petri dish, glass vessel, glass vessel with barriers in it, and cage with potted cotton plant), the predaceous efficiency of C. phyllochroma larvae varied with the predator density, the hunt constant (Q) and the intraspecific interference (m)increased with the prey density but decreased with the space heterogeneity; 2) In cage with potted cotton plant, the first- and second-instar green lacewing larvae consumed 13.6 and 29.4 cotton aphids/day respectively. The number of cotton aphids consumed by C. phyllochroma on lower leaves was significantly less than that on upper leaves; and 3) In cage with potted cotton plant, the percentage of the first- and second-instar green lacewing larvae located on upper leaves was significant less than that on lower leaves.

Comparison of the ionizing radiation effects on cochineal, annatto and turmeric natural dyes

Science.gov (United States)

Cosentino, Helio M.; Takinami, Patricia Y. I.; del Mastro, Nelida L.

2016-07-01

As studies on radiation stability of food dyes are scarce, commercially important natural food grade dyes were evaluated in terms of their sensitivity against gamma ionizing radiation. Cochineal, annatto and turmeric dyes with suitable concentrations were subjected to increasing doses up to 32 kGy and analyzed by spectrophotometry and capillary electrophoresis. The results showed different pattern of absorbance versus absorbed dose for the three systems. Carmine, the glucosidal coloring matter from the scale insect Coccus cacti L., Homoptera (cochineal) remained almost unaffected by radiation up to doses of about 32 kGy (absorbance at 494 nm). Meanwhile, at that dose, a plant-derived product annatto or urucum (Bixa orellana L.) tincture presented a nearly 58% reduction in color intensity. Tincture of curcumin (diferuloylmethane) the active ingredient in the eastern spice turmeric (Curcuma longa) showed to be highly sensitive to radiation when diluted. These data shall be taken in account whenever food products containing these food colors were going to undergo radiation processing.

Biodiversidad del complejo de artrópodos asociados al follaje de la vegetación del norte de Chile, II región Biodiversity of the canopy arthropods associated to vegetation of the north of Chile, II region

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FRANCISCO SAIZ

2000-12-01

, estableciéndose el siguiente gradiente decreciente: DL > DI > TM > TA. El contenido de cenizas de hojas y tallos también varía considerablemente y sigue el mismo patrón de variación que el contenido de agua. El contenido de nitrógeno foliar en las distintas zonas ecológicas estudiadas no varía tanto como el de agua, a excepción de TA en que son marcadamente inferiores. En cambio, en tallos es poco variable y no sigue el patrón de distribución foliar de este elemento, ni los patrones de distribución de los otros nutrientes considerados. En un enfoque global de las cuatro zonas se establece un gradiente decreciente de contenidos de agua, nitrógeno y cenizas desde el DL hasta la zona TA, concordante con el incremento en altitud, especialmente en lo referente a hojas. La familia Asteraceae muestra un definido gradiente decreciente del contenido de agua desde la costa a la alta cordillera. En cuanto al contenido foliar de cenizas difiere significativamente sólo entre DL y TM. En tallos no difiere significativamente. En total se colectaron 12.893 individuos de artrópodos asociados al follaje, distribuidos en 464 morfoespecies y 19 grupos zoológicos, considerando aparte a los antiguos Homoptera. Este grupo, junto a Hemiptera y larvas de Lepidoptera, destaca en cuanto a abundancia de especies dentro de los insectos fitófagos, así como Hymenoptera dentro de los parasitoides y Araneae entre los depredadores. En cuanto a las zonas ecológicas, el DL y TM presentan la mayor abundancia de artrópodos, tanto en especies como en individuos, así como de especies de plantas sobre las cuales se colectaron. La similaridad de la artropodofauna entre zonas ecológicas es mínima desde el punto de vista de la presencia de especies; en cambio, considerando sus abundancias, se detecta una tendencia a asociarse DI con TM y a aislarse el DL, al igual que ocurre con la vegetación. Desde el punto de vista de las diversidades específicas globales (H´ de los artrópodos se

Effect of Two Entomopathogenic Fungi in Controlling Aleurodicus cocois (Curtis, 1846 (Hemiptera: Aleyrodidae Efecto de Dos Hongos Entomopatógenos en el Control de Aleurodicus cocois (Curtis, 1846 (Hemiptera: Aleyrodidae

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Elizabeth Núñez del Prado

2008-03-01

Full Text Available Aleurodicus cocois (Curtis, 1846, the coconut whitefly, is a very damaging pest in Peru, mainly in avocado trees (Persea americana Mill.. It has been determined that entomopathogenic fungi can infect and kill white flies and can be used as biological control agents. The object of this research was to determine if there is any synergic action of the entomopathogenic fungi Paecilomyces fumosoroseus (Wize Brown & Smith 1957 and Verticillium lecanii (Zimmerman, 1892 Viégas 1939, in controlling A. cocois. Plastic sterile dishes were prepared where 5 mL 2% agar were used for each stage; leaves infested with A. cocois were placed upon these. Three different treatments were applied by sprinkling: P. fumosoroseus (P, V. lecanii (V or the mixture of the two fungi. These treatments were evaluated at one, two and seven days in the case of nymph I and eggs, and after four, eight and 12 days for nymph II, NIII and NIV. The lethal effect of V. lecanii on the second nymph instar of A. cocois was better than that of P. fumosoroseus and than the mixture of both fungi; the highest mortality percentage appeared from day eight to day 12. A small increase was observed in the effect of the mixture of the two entomopathogenic fungi on the IV nymph instar; and the effect of P. fumosoroseus was the lowestAleurodicus cocois (Curtis, 1846, la mosca blanca del cocotero, constituye una plaga muy importante en el Perú, principalmente en el palto (Persea americana Mill.. Se ha determinado que los hongos entomopatógenos pueden infectar y matar a la mosca blanca, por lo que podrían ser usados como agentes de control biológico. El objetivo del presente trabajo fue determinar si existe alguna acción conjunta de dos hongos entomopatógenos Paecilomyces fumosoroseus (Wize Brown & Smith 1957 y Verticillium lecanii (Zimmerman, 1892 Viégas 1939, en el control de A. cocois. Para ello se prepararon previamente placas de plástico estériles en las que se sirvieron aproximadamente 5 mL de agar al 2%, donde se colocaron hojas infestadas con A. cocois, aplicándose tres tratamientos por aspersión: P. fumosoroseus (P, V. lecanii (V y la mezcla de los dos hongos, los cuales se evaluaron en el caso de Ninfa I y huevos después de uno, dos y siete días, y para la Ninfas II, NIII y NIV cada cuatro, ocho y 12 días. El efecto de mortalidad de V. lecanii sobre el segundo estadío ninfal de A. cocois fue mejor que P. fumosoroseus y que la mezcla de ambos hongos, ya que el mayor porcentaje de mortalidad se presentó desde el octavo día hasta el día 12. En el caso del IV estadío ninfal se observó un ligero incremento en el efecto al combinarse los dos hongos entomopatógenos evaluados, siendo menor el efecto en P. fumosoroseus

Analysis of whitefly transcriptional responses to Beauveria bassiana infection reveals new insights into insect-fungus interactions.

Science.gov (United States)

Xia, Jun; Zhang, Chang-Rong; Zhang, Shan; Li, Fang-Fang; Feng, Ming-Guang; Wang, Xiao-Wei; Liu, Shu-Sheng

2013-01-01

The fungal pathogen, Beauveria bassiana, is an efficient biocontrol agent against a variety of agricultural pests. A thorough understanding of the basic principles of insect-fungus interactions may enable the genetic modification of Beauveria bassiana to enhance its virulence. However, the molecular mechanism of insect response to Beauveria bassiana infection is poorly understood, let alone the identification of fungal virulent factors involved in pathogenesis. Here, next generation sequencing technology was applied to examine the expression of whitefly (Bemisia tabaci) genes in response to the infection of Beauveria bassiana. Results showed that, compared to control, 654 and 1,681genes were differentially expressed at 48 hours and 72 hours post-infected whiteflies, respectively. Functional and enrichment analyses indicated that the DNA damage stimulus response and drug metabolism were important anti-fungi strategies of the whitefly. Mitogen-activated protein kinase (MAPK) pathway was also likely involved in the whitefly defense responses. Furthermore, the notable suppression of general metabolism and ion transport genes observed in 72 hours post-infected B. tabaci might be manipulated by fungal secreted effectors. By mapping the sequencing tags to B. bassiana genome, we also identified a number of differentially expressed fungal genes between the early and late infection stages. These genes are generally associated with fungal cell wall synthesis and energy metabolism. The expression of fungal cell wall protein genes might play an important role in fungal pathogenesis and the dramatically up-regulated enzymes of carbon metabolism indicate the increasing usage of energy during the fungal infection. To our knowledge, this is the first report on the molecular mechanism of fungus-whitefly interactions. Our results provide a road map for future investigations on insect-pathogen interactions and genetically modifying the fungus to enhance its efficiency in whitefly

Systems of organic farming in spring vetch I: Biological response of sucking insect pests

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Ivelina Nikolova

2015-04-01

Full Text Available Four systems of organic farming and a conventional farming system were studied over the period 2012-2014. The organic system trial variants included: I – an organic farming system without any biological products used (growth under natural soil fertility – Control; II – an organic farming system involving the use of a biological foliar fertilizer and a biological plant growth regulator (Polyversum+Biofa; III – an organic farming system in which a biological insecticide (NeemAzal T/S was used; IV – an organic farming system including a combination of three organic products: the foliar fertilizer, the plant growth regulator and the bioinsecticide (Polyversum+Biofa+NeemAzal T/S. Variant V represented a conventional farming system in which synthetic products were used in combination (foliar fertilizer, plant growth regulator and insecticide: Masterblend+Flordimex 420+Nurelle D. Treatment of vetch plants with the biological insecticide NeemAzal in combination with Biofa and Polyversum resulted in the lowest density of sucking pests, compared to all other organic farming methods tested (i.e. without NeemAzal, with NeemAzal alone, and its combination with Biofa and Polyversum. The greatest reduction in pest numbers during the vegetation period in that variant was observed in species of the order Thysanoptera (36.0-41.4%, followed by Hemiptera, and the families Aphididae (31.6-40.3% and Cicadellidae (27.3-28.6%. This combination showed an efficient synergistic interaction and an increase in biological efficacy as compared to individual application of NeemAzal. The highest toxic impact was found against Thrips tabaci, followed by Acyrthosiphon pisum. An analysis of variance regarding the efficacy against the species A. pisum, E. pteridis and T. tabaci showed that type of treatment had the most dominant influence and statistically significant impact.

Toxicidade do extrato aquoso das folhas de Anacardium humile para Bemisia tuberculata Toxicity of aqueous extract of Anacardium humile leaves on Bemisia tuberculata

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Nézio Nery de Andrade Filho

2010-08-01

Full Text Available A mosca-branca Bemisia tuberculata (Bondar, 1923 (Hem.: Aleyrodidae é uma das principais pragas da cultura da mandioca no Estado do Mato Grosso do Sul; no entanto, não há produtos registrados para seu controle. Produtos vegetais podem constituir em alternativa viável de controle de insetos e, por sua fotodegradabilidade, diminuir os riscos ao ambiente e ao homem. Objetivou-se, por meio deste trabalho, avaliar o efeito do extrato aquoso do "cajuzinho-do-cerrado" Anacardium humile St Hill (Anacardeaceae, nas concentrações de 2,0; 0,8; 0,4 e 0,05%, sobre a biologia de B. tuberculata, bem como identificar a classe de metabólitos secundários presentes no referido extrato. O experimento foi conduzido em casa de vegetação, sob temperatura de 26±4°C. O extrato aquoso de A. humile causou aumento da duração da fase larval e mortalidade significativamente superior à testemunha em todas as concentrações testadas. Concluiu-se que o extrato aquoso de folhas de A. humile provoca mortalidade em ninfas de B. tuberculata e alongamento da fase das ninfas sobreviventes. O extrato aquoso de folhas de A. humile apresenta taninos, açúcares redutores e saponinas, e o seu índice de espuma (Índice Afrosimétrico é de 1250.The whitefly Bemisia tuberculata (Bondar, 1923 (Hem.: Aleyrodidae is the main pest of cassava crops in Mato Grosso do Sul state, however there are no products registered for its control. Plant products may represent a viable alternative for insect pest control and, due to their photo-degradability, they may reduce risks to the environment and to man. The aim of this study is to assess the effect of "cajuzinho-do-cerrado" Anacardium humile St Hill (Anacardeaceae aqueous leaf extract on the biology of B. tuberculata at the concentrations 2.0; 0.8; 0.4; 0.05%, as well as to identify the class of secondary metabolites present in the referred extract. The experiment was carried out in a greenhouse at a temperature of 26±4°C. The

DNA barcode development for three recent exotic whitefly (Hemiptera: Aleyrodidae) invaders in Florida

Science.gov (United States)

Several new whitefly species have become established in Florida in the past decade. Three, in particular, have caused noticible damage to residential plants in the landscape such as ficus hedges, palms, and bird of paradise. These are fig whitefly (FW), rugose spiraling whitefly (RSW), and Bondar’s ...

The genus Baeturia Stål as represented in New Guinea (Homoptera, Cicadidae)

NARCIS (Netherlands)

Blöte, H.C.

1960-01-01

Until now only three species of the genus Baeturia have been recorded from New Guinea, viz., B. bicolorata Distant, B. viridicata Distant, and B. nana Jacobi. As I had the opportunity to study a fairly large collection of this group from different sources, collected in New Guinea, it appeared to me

Energetics of emergence in the cicadas, Cyclochila australasiae and Abricta curvicosta (Homoptera: Cicadidae).

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Harvey, Prudence M; Thompson, Michael B

2006-09-01

The final moult in cicadas marks a major transition in lifestyle and is a behaviour that makes the cicada vulnerable to predation. Consequently, emergence times are short and, we predict, therefore the rate of energy consumption would be high. Hence, we measured the energetic cost of emergence in Cyclochila australasiae (green grocer) and Abricta curvicosta (floury baker) cicadas during the final moult from nymph to adult cicada. Maximum energy expended whilst emerging was compared between the sexes and species. Even though C. australasiae take longer to emerge than A. curvicosta, the mass-specific cost of emergence is not different between the two species (C. australasiae: 11.34+/-2.55 J g(-1); A. curvicosta: 12.91+/-1.90 J g(-1)). The mass-specific metabolic rates of fully emerged adults of both species are approximately twice those of the nymphs and the maximum metabolic rate during emergence is about 1.5 times higher than the resting metabolic rate of emerged adults. Emergence times, as indicated by rates of oxygen consumption, are longer than expected and probably reflect limitations in the oxygen capacity of the cicadas during moulting.

Influences of pea morphology and interacting factors on pea aphid (Homoptera: Aphididae) reproduction.

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Buchman, N; Cuddington, K

2009-08-01

It has been claimed that plant architecture can alter aphid reproductive rates, but the mechanism driving this effect has not been identified. We studied interactions between plant architecture, aphid density, environmental conditions, and nutrient availability on the reproduction of pea aphids [Acyrthosiphon pisum (Harris)] using four near-isogenic peas (Pisum sativum L.) that differ in morphology. Manipulations of aphid density (1, 5, and 10 adults per plant) allowed us to examine any effects of plant morphology on crowding and consequently reproduction. Pea morphology per se did not alter pea aphid crowding, as measured by mean nearest neighbor distance, and there was no effect on reproduction. In addition, reproduction increased with increasing adult density, indicating positive density dependence. In a separate experiment, peas were fertilized to determine whether differences between nutrient availability of the four different morphologies might drive any observed differences in aphid reproduction. Although plant nitrogen content was altered by fertilization treatments, this did not have an impact on aphid reproduction. Greenhouse experiments, however, suggested that pea morphology can interact with environmental conditions to reduce aphid reproduction under some conditions. We conclude that plant morphology only influences aphid reproduction when environmental conditions are less than optimal.

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

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I NYOMAN WIJAYA

2015-09-01

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

The Hawaiian cave planthoppers (Homoptera: Fulgoroidea: Cixiidae - A model for rapid subterranean speciation?

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Hannelore Hoch

1997-01-01

Full Text Available After the successful colonization of a single ancestral species in the Hawaiian Islands, planthoppers of the cixiid genus Oliarus underwent intensive adaptive radiation resulting in 80 described endemic species. Oliarus habitats range from montaneous rain forests to dry coastal biotopes and subterranean environments. At least 7 independant evolutionary lines represented by different species have adapted to lava tubes on Molokai (1, Maui (3, and Hawaii Island (3. Behavioral and morphological studies on one of these evolutionary lines on Hawaii Island, the blind, flight- and pigmentless Oliarus polyphentus have provided evidence for reproductive isolation between allopatric populations which may in fact be separate species. Significant differences in song parameters were observed even between populations from neighbouring lava tubes, although the planthoppers are capable of underground migration through the voids and cracks of the mesocavernous rock system which is extant in young basalt: after a little more than 20 years, lava tubes within the Mauna Ulu 1974 flow had been colonized by O. ‘polyphenius” individuals, most probably originating from a near-by forestkipuka. Amazingly, this species complex is found on the youngest of the Hawaiian Islands, with probably less than 0.5 m.y., which suggests rapid speciation processes. Field observations have led to the development of a hypothesis to match underground speciation with the dynamics of vegetational succession on the surface of active volcanoes. Planthopper range partitioning and geographic separation of populations by young lava flows, founder events and small population size may be important factors involved in rapid divergence.

Collective defense of Aphis nerii and Uroleucon hypochoeridis (Homoptera, Aphididae against natural enemies.

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Manfred Hartbauer

2010-04-01

Full Text Available The prevalent way aphids accomplish colony defense against natural enemies is a mutualistic relationship with ants or the occurrence of a specialised soldier caste typical for eusocial aphids, or even both. Despite a group-living life style of those aphid species lacking these defense lines, communal defense against natural predators has not yet been observed there. Individuals of Aphis nerii (Oleander aphid and Uroleucon hypochoeridis, an aphid species feeding on Hypochoeris radicata (hairy cat's ear, show a behavioral response to visual stimulation in the form of spinning or twitching, which is often accompanied by coordinated kicks executed with hind legs. Interestingly, this behaviour is highly synchronized among members of a colony and repetitive visual stimulation caused strong habituation. Observations of natural aphid colonies revealed that a collective twitching and kicking response (CTKR was frequently evoked during oviposition attempts of the parasitoid wasp Aphidius colemani and during attacks of aphidophagous larvae. CTKR effectively interrupted oviposition attempts of this parasitoid wasp and even repelled this parasitoid from colonies after evoking consecutive CTKRs. In contrast, solitary feeding A. nerii individuals were not able to successfully repel this parasitoid wasp. In addition, CTKR was also evoked through gentle substrate vibrations. Laser vibrometry of the substrate revealed twitching-associated vibrations that form a train of sharp acceleration peaks in the course of a CTKR. This suggests that visual signals in combination with twitching-related substrate vibrations may play an important role in synchronising defense among members of a colony. In both aphid species collective defense in encounters with different natural enemies was executed in a stereotypical way and was similar to CTKR evoked through visual stimulation. This cooperative defense behavior provides an example of a surprising sociality that can be found in some aphid species that are not expected to be social at all.

Oxygenated phosphine fumigation for control of Nasonovia ribisnigri (Homoptera: Aphididae) on harvested lettuce.

Science.gov (United States)

Liu, Yong-Biao

2012-06-01

Low temperature regular phosphine fumigations under the normal oxygen level and oxygenated phosphine fumigations under superatmospheric oxygen levels were compared for efficacy against the aphid, Nasonovia ribisnigri (Mosley), and effects on postharvest quality of romaine and head lettuce. Low temperature regular phosphine fumigation was effective against the aphid. However, a 3 d treatment with high phosphine concentrations of > or = 2,000 ppm was needed for complete control of the aphid. Oxygen greatly increased phosphine toxicity and significantly reduced both treatment time and phosphine concentration for control of N. ribisnigri. At 1,000 ppm phosphine, 72 h regular fumigations at 6 degrees C did not achieve 100% mortality of the aphid. The 1,000 ppm phosphine fumigation under 60% O2 killed all aphids in 30 h. Both a 72 h regular fumigation with 2,200 ppm phosphine and a 48 h oxygenated fumigation with 1,000 ppm phosphine under 60% O2 were tested on romaine and head lettuce at 3 degrees C. Both treatments achieved complete control of N. ribisnigri. However, the 72 h regular fumigation resulted in significantly higher percentages of lettuce with injuries and significantly lower lettuce internal quality scores than the 48 h oxygenated phosphine fumigation. Although the oxygenated phosphine fumigation also caused injuries to some treated lettuce, lettuce quality remained very good and the treatment is not expected to have a significant impact on marketability of the lettuce. This study demonstrated that oxygenated phosphine fumigation was more effective and less phytotoxic for controlling N. ribisnigri on harvested lettuce than regular phosphine fumigation and is promising for practical use.

RNA interference for the control of whiteflies (Bemisia tabaci) by oral ...

Indian Academy of Sciences (India)

respective primers (table 2), and actin served as the internal control. Each reaction ..... emerged adults and variation in the quality and the quantity of siRNA synthesized ... Environment News Service, 21 August (countercurrents.org). Febvay G ...

Avaliação de inseticidas no controle de Myzus persicae (sulz. (homoptera: aphididae na cultura da alface Evaluation of insecticides to control Myzus persicae (Sulz (Homoptera: Aphididae on lettuce crop

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Jeferson Zagonel

2002-09-01

Full Text Available Foi avaliada a eficiência de inseticidas no controle de Myzus persicae (Sulz. na cultura da alface, cv. Verônica, em experimento conduzido na UEPG, em 1999. Usou-se delineamento experimental de blocos ao acaso com seis tratamentos e quatro repetições. Os tratamentos constaram de thiamethoxam nas doses de 50; 75 e 100 g i.a./ha; imidacloprid na dose de 140 g i.a./ha; pymetrozine na dose de 150 g i.a./ha e testemunha sem pulverização. Os tratamentos foram aplicados nas mudas em bandejas, um dia antes do transplantio. Avaliou-se a fitotoxicidade, o número de pulgões por planta, a porcentagem de plantas com pulgões e a eficiência dos inseticidas. O thiamethoxam nas doses de 50; 75 e 100 g i.a./ha foi eficiente no controle de M. persicae durante todo o ciclo, mostrando eficiência igual ou superior a 98,6%, similar ao imidacloprid. O pymetrozine apresentou eficiência no controle de M. persicae até 21 dias após o transplante das mudas. Os inseticidas não causaram efeitos fitotóxicos nas plantas de alface; além disso, houve produção de plantas com maior massa fresca em relação à testemunha.A field trial was carried out at Universidade Estadual de Ponta Grossa, State of Paraná, Brazil, in 1999, to evaluate the efficiency of insecticides in controlling Myzus persicae (Sulz on lettuce cv. Veronica. The experimental design was of completely randomized blocks with six treatments and four replications. The treatments consisted of thiamethoxam (50; 75 and 100 g i.a/ha imidacloprid (140 g i.a/ha; pymetrozine (150 g i.a/ha and control. The treatments were applied to seedlings grown in polyestyrene trays one day before the transplanting. The fitotoxicity, the number of aphids/plant, the percentage of plants with aphids and the efficiency of the insecticides were evaluated. Thiamethoxan at doses of 50; 75 and 100 g i.a/ha was efficient to control M. persicae from transplanting till 43 days after showing equal or higher efficiency than 98.6%, similar to imidacloprid. The pymetrozine was efficient to control M. persicae until 21 days after transplanting. Effects of fitotoxicity on lettuce plants were not observed. Higher fresh weight was observed in treated plants in comparison to the one of the control.

Are cicadas (Diceroprocta apache) both a "keystone" and a "critical-link" species in lower Colorado River riparian communities?

Science.gov (United States)

Andersen, Douglas C.

1994-01-01

Apache cicada (Homoptera: Cicadidae: Diceroprocta apache Davis) densities were estimated to be 10 individuals/m2 within a closed-canopy stand of Fremont cottonwood (Populus fremontii) and Goodding willow (Salix gooddingii) in a revegetated site adjacent to the Colorado River near Parker, Arizona. Coupled with data drawn from the literature, I estimate that up to 1.3 cm (13 1/m2) of water may be added to the upper soil layers annually through the feeding activities of cicada nymphs. This is equivalent to 12% of the annual precipitation received in the study area. Apache cicadas may have significant effects on ecosystem functioning via effects on water transport and thus act as a critical-link species in this southwest desert riverine ecosystem. Cicadas emerged later within the cottonwood-willow stand than in relatively open saltcedar-mesquite stands; this difference in temporal dynamics would affect their availability to several insectivorous bird species and may help explain the birds' recent declines. Resource managers in this region should be sensitive to the multiple and strong effects that Apache cicadas may have on ecosystem structure and functioning.

Isolation and in vitro cultivation of the aphid pathogenic fungus Entomophthora planchoniana.

Science.gov (United States)

Freimoser, F M; Jensen, A B; Tuor, U; Aebi, M; Eilenberg, J

2001-12-01

Entomophthora planchoniana is an important fungal pathogen of aphids. Although Entomophthora chromaphidis has been considered a synonym for E. planchoniana, the two species are now separated, and E. planchoniana is reported not to grow in vitro. In this paper, we describe for the first time the isolation and cultivation of this species. Entomophthora planchoniana was isolated from a population of Ovatus crataegarius (Homoptera, Aphididae), which was infected by E. planchoniana only. The isolates did not sporulate, but the sequence of the small subunit rDNA and the restriction fragment length polymorphism patterns of the first part of the large subunit rDNA and the ITS II region confirm that the isolates were E. planchoniana. The isolated fungus grew in a medium consisting of Grace's insect cell culture medium supplemented with lactalbumin hydrolysate, yeastolate, and 10% fetal bovine serum or in GLEN medium with 10% fetal bovine serum. Vegetative cells of E. planchoniana were long and club-shaped and did not stain with Calcofluor, thus suggesting that they were protoplasts.

Arthropod prey of Wilson's Warblers in the understory of Douglas-fir forests

Science.gov (United States)

Hagar, J.C.; Dugger, K.M.; Starkey, E.E.

2007-01-01

Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

Diet of Wilson's warblers and distribution of arthropod prey in the understory of Douglas-fir forests

Science.gov (United States)

Hagar, Joan C.; Dugger, Kate; Starkey, Edward E.

2007-01-01

Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

Entomofauna associated to horticultural crops under organic and conventional practices in Cordoba, Argentina

International Nuclear Information System (INIS)

Zalazar, Laura; Salvo, Adriana

2007-01-01

Farming practices and the addition of chemical synthetic substances in conventional agroecosystems are detrimental mainly to natural enemies of phytophagous insects, diminishing the natural regulation of pest insects. On the other hand, in organic agriculture, biological processes and care of the environment are favoured, hence an increase in insect biodiversity is predicted in this type of systems. In this work, abundance, richness of insects and proportion of functional groups were compared through a single quantitative sampling of insects in horticultural crop fields, three under organic and three under conventional management practices. Insect species richness, total and for guilds (phytophagous and entomophagous insects) were significantly higher in organic orchards, and also was the abundance of entomophagous insects. Richness and abundance of all insect orders (with exception of Homoptera abundance), were higher in orchards under organic management, being significant the differences for richness of Coleoptera and richness and abundance of Hymenoptera. Similar tendencies were observed in data obtained through sweep net in weeds. These results suggest that organic practices increase the diversity of species, particularly that of natural enemies. (author)

Entomofauna associated to horticultural crops under organic and conventional practices in Cordoba, Argentina; Entomofauna asociada a cultivos horticolas organicos y convencionales en Cordoba, Argentina

Energy Technology Data Exchange (ETDEWEB)

Zalazar, Laura; Salvo, Adriana [Universidade Nacional de Cordoba (Argentina). Facultad de Ciencias Exactas Fisicas y Naturales. Centro de Investigaciones Entomologicas de Cordoba (CIEC)

2007-09-15

Farming practices and the addition of chemical synthetic substances in conventional agroecosystems are detrimental mainly to natural enemies of phytophagous insects, diminishing the natural regulation of pest insects. On the other hand, in organic agriculture, biological processes and care of the environment are favoured, hence an increase in insect biodiversity is predicted in this type of systems. In this work, abundance, richness of insects and proportion of functional groups were compared through a single quantitative sampling of insects in horticultural crop fields, three under organic and three under conventional management practices. Insect species richness, total and for guilds (phytophagous and entomophagous insects) were significantly higher in organic orchards, and also was the abundance of entomophagous insects. Richness and abundance of all insect orders (with exception of Homoptera abundance), were higher in orchards under organic management, being significant the differences for richness of Coleoptera and richness and abundance of Hymenoptera. Similar tendencies were observed in data obtained through sweep net in weeds. These results suggest that organic practices increase the diversity of species, particularly that of natural enemies. (author)

Asociación Thysanoptera (Insecta-Vicia faba (Fabaceae en la Prepuna y Puna de Jujuy, Argentina Thysanoptera (Insecta-Vicia faba (Fabaceae association in Prepuna and Puna in Jujuy, Argentina

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María Inés Zamar

2012-03-01

Full Text Available Los distintos estados fenológicos de Vicia faba ofrecen recursos alimenticios y sustratos para el desarrollo de una importante diversidad de insectos. Los objetivos de este estudio fueron: identificar el complejo de tisanópteros antófilos, analizar las fluctuaciones de las poblaciones, conocer aspectos bioecológicos y determinar el rol que cumplen en esta asociación. El estudio se realizó durante el período floración-fructificación del cultivo de haba, en dos etapas y regiones fitogeográficas de Jujuy: Prepuna (2 479msnm, semanalmente desde octubre-diciembre de 1995-1996 y Puna (3 367msnm, quincenalmente desde diciembre 2007-marzo 2008. Cada muestra consistió de 25 flores tomadas al azar; sólo en Prepuna se realizó un muestreo complementario de tres golpes/planta (n=10 plantas. Se realizaron observaciones sobre sitios de oviposición, ingreso a la flor, lugares de pupación, comportamiento alimenticio y lesiones producidas. En Prepuna, el complejo de tisanópteros está formado por Frankliniella australis, F. occidentalis, F. gemina, F. schultzei y Thrips tabaci; en Puna la diversidad específica está restringida a F. australis y F. gemina. A pesar de que el período siembra-cosecha no coincide en ambas áreas, las fluctuaciones de las poblaciones presentan un mismo patrón: a medida que avanza la floración aumenta el número de tisanópteros, que coincide con la disponibilidad del recurso alimenticio. En ambas áreas, F. australis es la especie dominante y mantiene poblaciones sucesivas en el cultivo; deposita los huevos en los botones florales y las larvas eclosionan cuando se produce la apertura de las flores; la alimentación de larvas y adultos ocasiona manchas plateadas con puntuaciones negras. En la Prepuna, F. australis atraviesa los estados inmaduros móviles en las flores y los quiescentes en el suelo; en la Puna, todos los estados de desarrollo transcurren dentro de las flores. Thrips tabaci, F. gemina, F. shultzei y F

Biology of the citrus blackfly, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), in three host plants

International Nuclear Information System (INIS)

Pena, Marcia R.; Silva, Neliton M. da

2009-01-01

The citrus blackfly, Aleurocanthus woglumi Ashby, was detected in Brazil in 2001. The aim of this research was to evaluate the biology, biometry and host preference of A. woglumi in sweet orange, acid lime Tahiti and mango. Experiments were set in laboratory conditions with insects collected in rangpur lime plants in Manaus, State of Amazonas, from January to June of 2006. The following parameters were evaluated: number of spirals (ovo positions) and eggs per plant, number of eggs by spiral per plant, survival of the immature (eggs, 1st, 2nd, 3rd and 4th instars), and length and survival of the immature stage. The mean embrionary period was 15 days for the three hosts. The 4th nymph (puparium) was the longest during nymph development. Second and third instars had the highest survival. The mean length of the egg-adult cycle was 70 days for the three hosts evaluated. The eggs were laid in a spiral shape on the adaxial leaf surface. The 1st instars moved to short distances from the spiral, while the 2nd, 3rd and 4th are sessile and have bristles on the whole body. Based on the highest oviposition and the highest survival of the immature stage of the citrus blackfly in acid lime Tahiti, this plant can be considered the most suitable host to A. woglumi. (author)

Alimentação e fator de condição de peixes characidiíneos no sistema do Ribeirão Grande, Sudeste do Brasil - DOI: 10.4025/actascibiolsci.v27i3.1336 Feeding and condition factor of characidiin fish in Ribeirão Grande system, Southeastern Brazil - DOI: 10.4025/actascibiolsci.v27i3.1336

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Francisco Manoel de Souza Braga

2005-03-01

Full Text Available Os peixes foram amostrados quatro vezes em cada local, de julho de 2001 a abril de 2002: inverno (julho de 2001, primavera (outubro de 2001, verão (fevereiro de 2002 e outono (abril de 2002. Foram amostrados segmentos de cinco riachos no sistema do Ribeirão Grande (22o 47’ 08’’ S, 45o 28’ 17’’W. Coletas quantitativas foram feitas com um aparelho de pesca-elétrica ligado a um gerador com capacidade máxima de 1.500 V e 8,7 A de 600 Hz de corrente alternada. Alimentação, mudanças na gordura visceral e fator de condição foram comparados em duas espécies de characidiíneos, Characidium lauroi e C. Alipioi do sistema do Ribeirão Grande, sudeste do Brasil. Nas dietas das duas espécies ninfas de Ephemeroptera, foram registradas larvas de Diptera (Chironomidae, Simuliidae, ninfas de Plecoptera, larvas de Trichoptera (Hydroptilidae, Psychoyiidae, insetos terrestres (Coleoptera, Isoptera, Hemiptera [Heteroptera, Homoptera], larvas de Megaloptera (Corydalidae, Arachnida, Ostracoda e restos vegetais. A gordura visceral decresceu em fevereiro, coincidindo com o declínio do fator de condição em ambas as espécies. O aumento da atividade alimentar durante o verão proporciona o acúmulo de gordura. Durante as estações seguintes, esses peixes devem utilizar as reservas de gordura visceral para manutenção e reproduçãoFeeding, seasonal changes in visceral fat and condition factor were compared in two species of characidiin fishes, Characidium lauroi and C. alipioi from Ribeirão Grande system, southeastern Brazil. Five streams of Ribeirão Grande system were sampled (22o 47’ 08’’ S, 45o 28’ 17’’W. The samples were taken four times per site, from July, 2001 to April, 2002: winter (July 2001, spring (October 2001, summer (February 2002 and autumn (April 2002. Quantitative collections were made with an electro-fishing device powered by a generator with maximum capacity of 1,500 V and 8.7 A of 60 Hz alternating current

Bioacoustic investigations and taxonomic considerations on the Cicadetta montana species complex (Homoptera: Cicadoidea: Tibicinidae

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Matija Gogala

2004-06-01

Full Text Available Recent bioacoustic investigations have shown that Cicadetta montana Scopoli 1772 is a complex of morphologically similar sister species that are best characterized by their song patterns. At the type locality of C. montana, only mountain cicadas with simple, long lasting song phrases were heard, recorded and collected. Therefore, we have good reasons to suggest that this type of song is characteristic for C. montana s. str. Boulard described a song of C. montana from France with phrases composed of a long and a short echeme; this type of song is characteristic for cicadas morphologically corresponding to C. montana var. brevipennis Fieber 1876; we suggest to raise this taxon to species level. On the basis of specific song, Puissant and Boulard described C. cerdaniensis from Pyrénées. A similar case was the discovery and description of C. montana macedonica Schedl 1999 from Macedonia; since these Macedonian cicadas are sympatric with at least two other cryptic species in the C. montana group and molecular investigations showed substantial genetic differences between C. macedonica and C. montana or C. brevipennis, we conclude that this taxon should also be raised to species level. Songs of closely related C. podolica and Korean mountain cicada are presented as well.Pesquisas recentes de bioacústica mostraram que Cicadetta montana Scopoli 1772 é um complexo de espécie-irmãs morfologicamente semelhantes e melhor caracterizadas por seus padrões de canto. Na localidade-tipo de C. montana somente cigarras serranas de longas frases de canto foram ouvidas, gravadas e coletadas. Portanto, temos boas razões para propor este tipo de canto como característico de C. montana s. str. Boulard descreveu um canto de C. montana da França com frases compostas de uma estridulação longa e uma curta; este tipo de canto é característico das cigarras correspondendo morfologicamente a C. montana var. brevipennis Fieber 1876; sugerimos elevar este táxon ao nível de espécie. Baseando-se nos cantos específicos, Puissant e Boulard descreveram C. cerdaniensis dos Pirineus. Um caso similar foi a descoberta e descrição de C. montana macedonica Schedl 1999 da Macedônia; desde que essas cigarras macedônicas são simpátricas com pelo menos duas outras espécies crípticas dentro do grupo C. montana e as análises moleculares mostraram diferenças genéticas substanciais entre C. montana e C. brevipennis, concluímos que este táxon também deve ser elevado ao nível de espécie. Cantos de espécies próximas, C. podolica e a cigarra serrana da Korea, são também apresentados.

Ultralow oxygen treatment for postharvest control of Nasonovia ribisnigri (Homoptera: Aphididae) on iceberg lettuce.

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Liu, Yong-Biao

2005-12-01

The aphid Nasonovia ribisnigri (Mosley) is a common pest of lettuce in the United States. It hinders export of U.S. lettuce to the overseas market such as Japan where it is a quarantined pest. Ultralow oxygen treatments were studied for control of the insect on iceberg lettuce. Small-scale ultralow oxygen treatments in plastic jars were conducted at 1, 5, and 10 degrees C for different durations to determine effective treatment against nymphs and alates of N. ribisnigri. At oxygen levels of 0.015-0.025%, N. ribisnigri can be controlled in 3 d at 1 degrees C, 2 d at 5 degrees C, and 1 d at 10 degrees C. Large-scale ultralow oxygen treatments were conducted in bulk container treatment chambers with commercial iceberg lettuce heads for 2 d at 6 degrees C with oxygen levels of 0.015 and 0.025% and for 3 d at 3 degrees C with oxygen level of 0.015%. All treatments achieved complete control of N. ribisnigri. No negative impact on lettuce quality was detected after 2 wk of posttreatment storage. Therefore, the selected treatments have potential to be commercially developed for postharvest control of N. ribisnigri on iceberg lettuce.

Biology and taxonomy of Tuthillia cognata (Homoptera : Psylloidea), a pest on Myrciaria dubia (Myrtaceae)

OpenAIRE

Burckhardt, D.; Couturier, Guy

1988-01-01

#Tuthillia cognata$ est découvert comme ravageur de #Myrciaria dubia$ (#Myrtaceae$) au Pérou et Brésil. Tenant compte de la morphologie de la larve, le genre est transféré des #Ciriacreminae$ dans les #Anomoneurinae$. (Résumé d'auteur)

Comparing the regional epidemiology of the cassava mosaic and cassava brown streak virus pandemics in Africa.

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Legg, J P; Jeremiah, S C; Obiero, H M; Maruthi, M N; Ndyetabula, I; Okao-Okuja, G; Bouwmeester, H; Bigirimana, S; Tata-Hangy, W; Gashaka, G; Mkamilo, G; Alicai, T; Lava Kumar, P

2011-08-01

The rapid geographical expansion of the cassava mosaic disease (CMD) pandemic, caused by cassava mosaic geminiviruses, has devastated cassava crops in 12 countries of East and Central Africa since the late 1980s. Region-level surveys have revealed a continuing pattern of annual spread westward and southward along a contiguous 'front'. More recently, outbreaks of cassava brown streak disease (CBSD) were reported from Uganda and other parts of East Africa that had been hitherto unaffected by the disease. Recent survey data reveal several significant contrasts between the regional epidemiology of these two pandemics: (i) severe CMD radiates out from an initial centre of origin, whilst CBSD seems to be spreading from independent 'hot-spots'; (ii) the severe CMD pandemic has arisen from recombination and synergy between virus species, whilst the CBSD pandemic seems to be a 'new encounter' situation between host and pathogen; (iii) CMD pandemic spread has been tightly linked with the appearance of super-abundant Bemisia tabaci whitefly vector populations, in contrast to CBSD, where outbreaks have occurred 3-12 years after whitefly population increases; (iv) the CMGs causing CMD are transmitted in a persistent manner, whilst the two cassava brown streak viruses appear to be semi-persistently transmitted; and (v) different patterns of symptom expression mean that phytosanitary measures could be implemented easily for CMD but have limited effectiveness, whereas similar measures are difficult to apply for CBSD but are potentially very effective. An important similarity between the pandemics is that the viruses occurring in pandemic-affected areas are also found elsewhere, indicating that contrary to earlier published conclusions, the viruses per se are unlikely to be the key factors driving the two pandemics. A diagrammatic representation illustrates the temporal relationship between B. tabaci abundance and changing incidences of both CMD and CBSD in the Great Lakes region

Anagrus breviphragma Soyka Short Distance Search Stimuli

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Elisabetta Chiappini

2015-01-01

Full Text Available Anagrus breviphragma Soyka (Hymenoptera: Mymaridae successfully parasitises eggs of Cicadella viridis (L. (Homoptera: Cicadellidae, embedded in vegetal tissues, suggesting the idea of possible chemical and physical cues, revealing the eggs presence. In this research, three treatments were considered in order to establish which types of cue are involved: eggs extracted from leaf, used as a control, eggs extracted from leaf and cleaned in water and ethanol, used to evaluate the presence of chemicals soluble in polar solvents, and eggs extracted from leaf and covered with Parafilm (M, used to avoid physical stimuli due to the bump on the leaf surface. The results show that eggs covered with Parafilm present a higher number of parasitised eggs and a lower probing starting time with respect to eggs washed with polar solvents or eggs extracted and untreated, both when the treatments were singly tested or when offered in sequence, independently of the treatment position. These results suggest that the exploited stimuli are not physical due to the bump but chemicals that can spread in the Parafilm, circulating the signal on the whole surface, and that the stimuli that elicit probing and oviposition are not subjected to learning.

Food habits of the southwestern willow flycatcher during the nesting season

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Drost, Charles A.; Paxton, Eben H.; Sogge, Mark K.; Whitfield, Mary J.

2003-01-01

The food habits and prey base of the endangered Southwestern Willow Flycatcher (Empidonax traillii extimus) are not well known. We analyzed prey remains in 59 fecal samples from an intensively-studied population of this flycatcher at the Kern River Preserve in southern California. These samples were collected during the nesting season in 1996 and 1997 from adults caught in mist nets, and from nestlings temporarily removed from the nest for banding. A total of 379 prey individuals were identified in the samples. Dominant prey taxa, both in total numbers and in percent occurrence, were true bugs (Hemiptera), flies (Diptera), and beetles (Coleoptera). Leafhoppers (Homoptera: Cicadellidae), spiders (Araneae), bees and wasps (Hymenoptera), and dragonflies and damselflies (Odonata) were also common items. Diet composition was significantly different between years, due to a large difference in the numbers of spiders between 1996 and 1997. There was also a significant difference between the diet of young and adults, with the diet of young birds having significantly higher numbers of odonates and beetles. There was a trend toward diet differences between males and females, but this was not significant at the P = 0.05 level.

Insectes ravageurs et propriétés biocides de Jatropha curcas L. (Euphorbiaceae : synthèse bibliographique

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Abdoul Habou, Z.

2013-01-01

Full Text Available Insect pests and biocidal properties of Jatropha curcas L. (Euphorbiaceae. A review. Jatropha curcas is a Euphorbiaceae shrub widely distributed in many tropical countries. Its seeds are rich in oil that can be used as biofuel in modified diesel engines. Several insect species, mainly belonging to Hemiptera, Coleoptera and Orthoptera, have been referenced as insect pests of J. curcas. These insects attack the plant and cause damage to fruits, inflorescences and leaves. The most frequently observed pests belong to the genus Pachycoris (Heteroptera: Scutelleridae, which are widely distributed in Mexico, Australia, United States of America, Brazil and Nicaragua. Pachycoris spp. cause significant damage to the fruits, leading to the malformation of seeds and a reduction in their oil content. Although Jatropha shrubs are subjected to insect infestations, the oil has been shown to demonstrate biocidal activity, including insecticidal effects against several insect pests, including Busseola fusca (Fuller (Lepidoptera: Noctuidae, Sesamia calamistis Hampson (Lepidoptera: Noctuidae, Aphis gossypii Glover (Homoptera: Aphididae and Callosobruchus chinensis L. (Coleoptera: Bruchidae. In the present paper, we summarize the work carried out on inventories of J. curcas insect pests as well as on the biocidal activity of its oil.

Búsqueda y reconocimiento de los enemigos naturales y hospedantes alternos de las principales plagas. En flores bajo invernadero en la sabana de Bogotá

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Martha E. Andrade

1989-01-01

Full Text Available Las plagas que atacan cultivos de llores bajo invernadero son cada vez más importantes por la gravedad de su daño y por la alta densidad con que suelen presentarse. Para su control se ha acudido principalmente a la utilización de productos químicos, lo cual conduce a un aumento en los costos de producción, a contaminar el medio ambiente, a afectar la salud humana y a crear resistencia de los insectos a los insecticidas. Debido a esto, es necesario incluír dentro de los programas de control a los reguladores naturales de las plagas: parasitoides, depredadores y microorganismos entornógenos. En el presente trabajo se registran los enemigos naturales más importantes de las principales plagas en llores bajo invernadero (crisantemo, rosa y clavel: Liriomyza huidobrensis Blanchard, L. trifolii Burgess (Diptera: Agrornyzídae; Myzuz persicae Sulzer (Homoptera: Aphididae; Tetranychus urticae Koch y T. cinnabarinus Boísduval (Acarina: Tetranychidae; también se señalan las plantas hospedantes alternas presentes en las localidades donde se realizó la investigación.

A survey of syrphid predators of Nasonovia ribisnigri in organic lettuce on the central coast of California.

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Smith, Hugh A; Chaney, William E

2007-02-01

Organic lettuce, Lactuca sativa L., producers on California's Central Coast rely on endemic syrphid flies (Diptera: Syrphidae) to suppress populations of Nasonovia ribisnigri Mosley (Homoptera: Aphididae) and other aphids affecting lettuce. Growers are using various forms of habitat manipulation to enhance biological control. We surveyed syrphids collected from organic romaine in and around the Salinas Valley from March through September 2005 to gain a better understanding of the species responsible for aphid suppression and to examine possible implications for biocontrol. The primary species of syrphid fly reared were Toxomerus marginatus (Say) (39%), Platycheirus stegnus (Say) (27%), Sphaerophoria sulfuripes (Thomson) (13%), and Allograpta obliqua (Say) (10%). Syrphus opinator Osten Sacken (2%), Toxomerus occidentalis (Curran) (1.3%), and Eupeodes volucris Osten Sacken (1%) were less common. Sphaerophoria pyrrhina Bigot, Scaeva pyrastri (L.), Platycheirus obscurus Say, Allograpta exotica Wiedemann, and Eupeodes americanus Wiedemann each made up aphids. P. stegnus was observed to deposit in clusters of eggs, and was only reared in significant numbers from highly infested fields. Approximately 5% of syrphid larvae overall were parasitized by either Diplazon sp. (Hymenoptera: Ichneumonidae) or Pachyneuron sp. (Hymenoptera: Pteromalidae).

Application of RNA-seq for mitogenome reconstruction, and reconsideration of long-branch artifacts in Hemiptera phylogeny

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Song, Nan; An, Shiheng; Yin, Xinming; Cai, Wanzhi; Li, Hu

2016-01-01

Hemiptera make up the largest nonholometabolan insect assemblage. Despite previous efforts to elucidate phylogeny within this group, relationships among the major sub-lineages remain uncertain. In particular, mitochondrial genome (mitogenome) data are still sparse for many important hemipteran insect groups. Recent mitogenomic analyses of Hemiptera have usually included no more than 50 species, with conflicting hypotheses presented. Here, we determined the nearly complete nucleotide sequence of the mitogenome for the aphid species of Rhopalosiphum padi using RNA-seq plus gap filling. The 15,205 bp mitogenome included all mitochondrial genes except for trnF. The mitogenome organization and size for R. padi are similar to previously reported aphid species. In addition, the phylogenetic relationships for Hemiptera were examined using a mitogenomic dataset which included sequences from 103 ingroup species and 19 outgroup species. Our results showed that the seven species representing the Aleyrodidae exhibit extremely long branches, and always cluster with long-branched outgroups. This lead to the failure of recovering a monophyletic Hemiptera in most analyses. The data treatment of Degen-coding for protein-coding genes and the site-heterogeneous CAT model show improved suppression of the long-branch effect. Under these conditions, the Sternorrhyncha was often recovered as the most basal clade in Hemiptera. PMID:27633117

Occurrence of Entomopathogenic Fungi from Agricultural and Natural Ecosystems in Saltillo, México, and their Virulence Towards Thrips and Whiteflies

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Sánchez-Peña, Sergio R.; Lara, Jorge San-Juan; Medina, Raúl F.

2011-01-01

Entomopathogenic fungi were collected from soil in four adjacent habitats (oak forest, agricultural soil, pine reforestation and chaparral habitat) in Saltillo, México using the insect bait method with Tenebrio molitor (L.) (Coleoptera: Tenebrionidae) larvae as bait. Overall, of the larvae exposed to soil, 171 (20%) hosted Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae), 25 (3%) hosted Metarhizium anisopliae (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae) and 1 (0.1%) hosted lsaria (=Paecilomyces) sp. (Hypocreales: Cordycipitaceae). B. bassiana was significantly more frequent on larvae exposed to oak forest soil. M. anisopliae was significantly more frequent on larvae exposed to agricultural soil. From the infected bait insects, 93 isolates of B. bassiana and 24 isolates of M. anisopliae were obtained. Strains were tested for their infectivity against Cuban laurel thrips, Gynaikothrips uzeli Zimmerman (Thysanoptera: Phlaeothripidae) and the greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). B. bassiana isolates caused the highest mortality on thrips (some causing 88% mortality after 6 days); both fungal species caused similarly high mortality levels against whiteflies (75%) after 6 days. Large amounts of germplasm of entomopathogenic fungi, fundamentally B. bassiana and M. anisopliae, exist in the habitats sampled; pathogenicity varied among strains, and some strains possessed significant virulence. Soils in these habitats are reservoirs of diverse strains with potential for use in biocontrol. PMID:21521145

[Occurrence of Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) in the state of Maranhão, Brazil].

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de Lemos, Raimunda N S; da Silva, Gilson S; Araújo, José R G; Das Chagas, Evandro F; Moreira, Aldenise A; Soares, Ana T M

2006-01-01

Aleurocanthus woglumi Ashby in citrus and mango crops in the state of Maranhão, Brazil, is recorded. Samples of 2003 and 2004 from several counties were identified and deposited in the Insect Collection of the Laboratório de Entomologia of the Núcleo de Biotecnologia Agronômica, Universidade Estadual do Maranhão.

Annual Fire, Mowing and Fertilization Effects on Two Cicada Species (Homoptera: Cicadidae) in Tallgrass Prairie

Science.gov (United States)

Mac A. Callaham; Matt R. Whiles; John M. Blair

2002-01-01

In tallgrass prairie, cicadas emerge annually, are abundant and their emergence can be an important flux of energy and nutrients. However, factors influencing the distribution and abundance of these cicadas are virtually unknown. We examined cicada emergence in plots from a long-term (13 y) experimental manipulation involving common tallgrass prairie management...

The tribe Acutalini Fowler (Homoptera, Membracidae, Smiliinae: new genera, new species and some nomenclatural changes

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Albino M Sakakibara

1997-09-01

Full Text Available The tribe Acutalini Fowler is redescribed as well as the genera Acutalis Fairmaire, Euritea Stål, and Thrasymedes Kirkaldy. The following new taxa and nomenclatural changes are presented: Thrasymedes mexicana sp.n. (from Mexico, Oaxaca; Bordonia gen.n., with B. venezuelana sp.n. (type-species (from Venezuela, Portachuelo, B. clypeata sp.n. (from Colombia, Cuesta Boba, B. majuscula sp.n. (from Venezuela, Portachuelo, and Cornutalis gen.n., with C. cauca sp.n. (type-species (from Colombia, Cauca, and C. validu sp.n. (from Ecuador, Sto. Domingo. Acutalis fusconervosa Fairmaire, 1846 = Horiola venosa Walker, 1858, syn.n.; Euritea munda (Walker, 1858 = Stictolobus nitidus Funkhouser, 1940, syn.n.; Bordonia nigricosta (Goding, 1926, comb.n.; Bordonia virescens (Funkhouser, 1940, comb.n.. One species is transferred to Smiliinae-Ceresini: Tapinolobus curvispina (Walker, 1858, comb.n. (formerly in Thrasymedes = Tapinolobus fasciatus Sakakibara, 1969, syn.n.; another one is transferred to Darninae-Cymbomorphini: Eumela darnioides (Walker, 1858, comb.n. (formerly in Euritea.

Distributional patterns and possible origins of the tribes and genera of Coelidiinae (Homoptera, Membracoidea, Cicadellidae

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Mervin W Nielson

2000-12-01

Full Text Available Leafhoppers are well known biological indicators of zoogeographical regions owing, in part, to their phytodependency, high host plant specificity and relatively low vagility. In this connection, we discuss distributional patterns and possible zoogeographical origins of nine constituent tribes and their genera of the pantropical subfamily Coelidiinae. Among 118 known genera, only eight currently occupy more than one zoogeographical region, indicating an extremely high endemic profile which supports the proposed centers of origin and relatively low rate of intercontinental dispersal. The pantropical tribe Coelidiini is suggested as the basal group of the subfamily which is believed to have arisen prior to continental drift (late Jurassic-early Cretaceous because there appears to be no other evidence at the present time to explain its near cosmopolitan distribution. Possible origins of three Old World tribes, Hikangiini (Ethiopian, Thagriini (Oriental and Thanini (Australian and four New World -(Neotropical tribes, Teruliini, Tinobregmini, Gabritini and Sandersellini are elucidated. The tribe Youngolidiini occupies the Neotropical and Ethiopian realms but its origin is problematical. There appears to be ample evidence that origin/dispersal patterns are related to the geological history of the areas occupied by its faunal members.

Appearance of cicada fauna (Homoptera: Cicadoidea) by altitudes in Johor National Park, Mount Ledang, Johor

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Tahir, Aliadi Mohd; Sulaiman, Azman

2015-09-01

A total of 31 cicada species in 15 genera under two families (Cicadidae, 27 species in 11 genera; Tibicinidae, four species in three genera) was recorded for Johor National Park, Mount Ledang, Johor. This was based on 666 individuals were obtained through six sampling occasions in November 2012 until October 2013, each time using light trap set in six sampling locations (L1, L2, L3, L4a, L4b, L4c) that were selected based on altitudes. The most common and abundant species in L1 is Pomponia sp1 and recognized as new species that need to be described as new to science. Orientopsaltria saudarapadda Duffles & Zaidi appeared as the most common and abundant species in L2, represented by 21 individuals which covers 34.43 % of the total cicadas specimen in that area. In the location of L3, Dundubia vaginata (Fabricius) appeared as the most abundant species represented by 37 individuals or 26.81% while Abroma maculicollis Guerin appeared as the most common species. Shannon's Species Diversity Index (H') in L3 was the highest (H'=2.28) followed by L4b (H'=2.21), L2 (H'=1.93) L4a (H'=1.92), L4c (H'=1.84) and L1 (H'=1.58), and the evenness index in L1 was the highest (E= 0.88), followed by L4b (E= 0.79), L3 (E= 0.77), L2 (E= 0.75), L4c (E= 0.74) and L4a (E= 0.79). Margalef Species Richness Index in L3 was the highest (R'=3.65), followed by oleh L4b (R'=3.01), L4a (R'=2.97), L2 (R'=2.92), L4c (R'=2.4), and L1 (R'=2.01). Generally shows that L3 at the altitude 350 m appear as the best sampling site for cicadas species in Mount Ledang Johor with the highest value of species diversity and richness index.

The Toxicity and Detoxifying Mechanism of Cycloxaprid and Buprofezin in Controlling Sogatella furcifera (Homoptera: Delphacidae).

Science.gov (United States)

Chang, Xiaoli; Yuan, Yongda; Zhang, Tianshu; Wang, Dongsheng; Du, Xingbin; Wu, Xiangwen; Chen, Haixia; Chen, Yaozhong; Jiao, Yuetong; Teng, Haiyuan

2015-01-01

The effects of cycloxaprid (a modified neonicotinoid insecticide) and buprofezin (a thiadiazine insecticide) on mortality of the white-backed planthopper (WBPH), Sogatella furcifera, were determined in laboratory assays. Cycloxaprid killed WBPH nymphs and adults but buprofezin killed only nymphs, and cycloxaprid acted faster than buprofezin. One day after infestation, mortality of third-instar nymphs was >65% with cycloxaprid at 125 mg liter(-1) but was buprofezin at 148 mg liter(-1). By the 4th day after infestation, however, control of nymphs by the two insecticides was similar, and cycloxaprid at 125 mg liter(-1) caused ≥ 80% mortality of adults but buprofezin at 148 mg liter(-1) (the highest rate tested) caused almost no adult mortality. LC50 values for cycloxaprid were lowest with nymphs, intermediate with adult males, and highest with adult females. Although buprofezin was slower acting than cycloxaprid, its LC50 for nymphs 5 d after infestation was 3.79-fold lower than that of cycloxaprid. Mean carboxylesterase (CarE) specific activity of nymphal WBPH treated with cycloxaprid and buprofezin was higher than that of control, but there was no significant difference between cycloxaprid and control (no insecticide), and it was significantly higher for buprofezin than those of cycloxaprid and control. For glutathione S-transferase and mixed function oxygenase, the specific activity of nymphal WBPH treated with buprofezin was significantly higher than those of cycloxaprid and control, too. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

The Toxicity and Detoxifying Mechanism of Cycloxaprid and Buprofezin in Controlling Sogatella furcifera (Homoptera: Delphacidae)

OpenAIRE

Chang, Xiaoli; Yuan, Yongda; Zhang, Tianshu; Wang, Dongsheng; Du, Xingbin; Wu, Xiangwen; Chen, Haixia; Chen, Yaozhong; Jiao, Yuetong; Teng, Haiyuan

2015-01-01

The effects of cycloxaprid (a modified neonicotinoid insecticide) and buprofezin (a thiadiazine insecticide) on mortality of the white-backed planthopper (WBPH), Sogatella furcifera, were determined in laboratory assays. Cycloxaprid killed WBPH nymphs and adults but buprofezin killed only nymphs, and cycloxaprid acted faster than buprofezin. One day after infestation, mortality of third-instar nymphs was >65% with cycloxaprid at 125?mg liter?1 but was

Microsatellite marker analysis of peach-potato aphids (Myzus persicae, Homoptera: Aphididae) from Scottish suction traps.

Science.gov (United States)

Malloch, G; Highet, F; Kasprowicz, L; Pickup, J; Neilson, R; Fenton, B

2006-12-01

The peach-potato aphid Myzus persicae (Sulzer) is an important vector of plant viruses. A network of suction traps collects aerial samples of this aphid in order to monitor and help predict its spatial distribution and likely impact on virus transmission in crops. A suction trap catch is thought to be a good representation of the total aphid pool. Sensitive molecular markers have been developed that determine the genetic composition of the M. persicae population. In Scotland, UK, these were applied to field collections revealing a limited number of clones. Molecular markers are less successful when applied to specimens that have been preserved in an ethanol-based trap fluid designed to preserve morphology. An assessment of different DNA extraction and PCR techniques is presented and the most efficient are used to analyse M. persicae specimens caught in the Dundee suction trap in 2001, a year when exceptionally high numbers were caught. The results reveal that the majority of the M. persicae caught belonged to two highly insecticide resistant clones. In addition, it was possible to compare the relative frequencies of genotypes caught in the trap with those collected at insecticide treated and untreated field sites in the vicinity. These results indicate that, in addition to suction trap data, the ability to sample field sites provides valuable early warning data which have implications for pest control and virus management strategies.

The authority and types for the hackberry gall psyllid genus Pachypsylla (Riley) (Hemiptera-Homoptera: Psyllidae)

Science.gov (United States)

The nomenclatural problems with the hackberry gall psyllid species names are rectified. The genus Pachypsylla Riley, 1883, type species, Psylla venusta Osten-Sacken, includes 14 nominal species. These are: Pachypsylla venusta (Osten-Sacken, 1861); P. celtidismamma Riley, 1875; P. celtidisgemma Ri...

Repellency and toxicity of three Impatients species (Balsaminaceae) extracts on Myzus persicae Sulzer (Homoptera: Aphididae)

Czech Academy of Sciences Publication Activity Database

Pavela, R.; Vrchotová, Naděžda; Šerá, Božena

2009-01-01

Roč. 2009, - (2009), s. 48-51 ISSN 0974-391X R&D Projects: GA MZe(CZ) QH72117 Institutional research plan: CEZ:AV0Z60870520 Keywords : Impatiens * repellency * toxicity Subject RIV: EH - Ecology, Behaviour

Identification of Russian wheat aphid (Homoptera : Aphididae) populations virulent to the Dn4 resistance gene

Czech Academy of Sciences Publication Activity Database

Smith, C. M.; Belay, T.; Stauffer, CH.; Starý, Petr; Kubečková, I.; Starkey, S.

2004-01-01

Roč. 97, č. 3 (2004), s. 1112-1117 ISSN 0022-0493 R&D Projects: GA AV ČR IBS5007102 Grant - others:Kansas Agricultural Experiment Station(US) 04-120-J Institutional research plan: CEZ:AV0Z5007907 Keywords : Diuraphis noxia * barley * virulence Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 1.283, year: 2004

Isolation and characterization of polymorphic microsatellite loci in the green leafhopper Empoasca vitis Goethe (Homoptera).

Science.gov (United States)

Papura, D; Giresse, X; Chauvin, B; Caron, H; Delmotte, F; VAN Helden, M

2009-05-01

Eight dinucleotide microsatellite loci were isolated and characterized within the green leafhopper Empoasca vitis (Goethe) using an enrichment cloning procedure. Primers were tested on 171 individuals collected in the southwest of France from the vine plants. The identified loci were polymorphic, with allelic diversity ranging from two to 18 alleles per locus. Observed heterozygosities were from 0.021 to 0.760. These microsatellite markers should prove to be a useful tool for estimating the population genetic structure, host-plant specialization and migration capacity of this insect. © 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd.

Effectiveness of electron irradiation as a quarantine treatment of cut flowers

International Nuclear Information System (INIS)

Hayashi, T.; Todoriki, S.; Nakakita, H.; Dohino, T.; Tanabe, K.

1999-01-01

The effects of electron beams on spider mite (Tetranychus urticae) and flour beetle (Tribolium freemani) were slightly smaller than those of gamma-rays. 'Soft-electrons' (low-energy electrons) at an energy of 170 keV inactivated eggs, larvae, pupae, and adults of the flour beetle. Electron beams at doses up to 400 Gy killed or sterilized all the pests for cut flowers tested; spider mite (Tetranychus urticae), mealybug (Pseudococcus comstocki), leaf miner (Liriomyza trifolii), thrips (Thrips palmi, Thrips tabaci), cutworm (Spodoptera litura), and aphid (Myzus persicae). Carnation, alstromeria, gladiolus, tulip, statice, stock, dendrobium, prairie gentian, oncidium, campanula, gloriosa, fern, gypsophila, freesia, lobelia, triteleia, and gerbera were resistant to radiation, while chrysanthemum, rose, lily, calla, antherium, sweet pea, and iris were sensitive. Radiation-induced deterioration of chrysanthemum could be prevented by post-irradiation treatment with commercial preservative solutions or sugar solutions. (author)

Test for Local Insect Traps against some Solanacea Insects Plant under Green House Conditions in Riyadh, Saudi Arabia

International Nuclear Information System (INIS)

Al-Ayedh, Hassan Ibn Yahiya

2005-01-01

Trapping efficiency of seven different colored sticky traps (Green, Fluorescent yellow, Orange, Pink, red, White and Yellow) was evaluated in some solanacea plants, tomatoes (Lycopersicon esculentum), eggplant (Solanum Magellan) and sweet pepper (Capsicum spp.) crops, for whitefly (Bemis ia airlifting), leaf miners (Liriomyza trifolii), thrips (Thrips tabaci) in Riyadh, Saudi Arabia. The traps were placed at four different heights (0.5, 1.0, 1.5 and 2.0 m above the ground). The experiment was laid out in a Completely Randomized Block Design (CRBD) with four replications during autumn 2001, spring and autumn 2002. Significantly high insect populations were trapped on Fluorescent yellow, yellow and green colored sticky traps. No significant differences were witnessed between mean numbers of various insects caught on sticky traps placed at different heights but more insects were trapped at 0.5 - 1.5m. (author)

Pre-infestation of Tomato Plants by Aphids Modulates Transmission-Acquisition Relationship among Whiteflies, Tomato Yellow Leaf Curl Virus (TYLCV and Plants

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Xiao L. Tan

2017-09-01

Full Text Available Herbivory defense systems in plants are largely regulated by jasmonate-(JA and salicylate-(SA signaling pathways. Such defense mechanisms may impact insect feeding dynamic, may also affect the transmission-acquisition relationship among virus, plants and vectoring insects. In the context of the tomato – whitefly – Tomato Yellow Leaf Curl Virus (TYLCV biological model, we tested the impact of pre-infesting plants with a non-vector insect (aphid Myzus persicae on feeding dynamics of a vector insect (whitefly Bemisia tabaci as well as virus transmission-acquisition. We showed that an aphid herbivory period of 0–48 h led to a transient systemic increase of virus concentration in the host plant (root, stem, and leaf, with the same pattern observed in whiteflies feeding on aphid-infested plants. We used real-time quantitative PCR to study the expression of key genes of the SA- and JA-signaling pathways, as well as electrical penetration graph (EPG to characterize the impact of aphid pre-infestation on whitefly feeding during TYLCV transmission (whitefly to tomato and acquisition (tomato to whitefly. The impact of the duration of aphid pre-infestation (0, 24, or 48 h on phloem feeding by whitefly (E2 during the transmission phase was similar to that of global whitefly feeding behavior (E1, E2 and probing duration during the acquisition phase. In addition, we observed that a longer phase of aphid pre-infestation prior to virus transmission by whitefly led to the up-regulation and down-regulation of SA- and JA-signaling pathway genes, respectively. These results demonstrated a significant impact of aphid pre-infestation on the tomato – whitefly – TYLCV system. Transmission and acquisition of TYLCV was positively correlated with feeding activity of B. tabaci, and both were mediated by the SA- and JA-pathways. TYLCV concentration during the transmission phases was modulated by up- and down-regulation of SA- and JA-pathways, respectively. The two

Adaptation of bacteriophages to new hosts through overcoming the interspecific barrier

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Е. N. Andriychuk

2016-10-01

Full Text Available Four wild type phage isolates were tested on P. syringae isolated from potato tuber samples collected in the Kiev and Cherkasy regions of Ukraine. The isolated phages formed clear plaques and had a virion size of 2 to 12 nm. Electron microscopy showed that the phages were of similar size and structure and consisted of isometric particles with long tails characteristic of the Podoviridae family. The effectiveness of phage culturing on bacteria different from the original host was also studied on two phytopathogenic strains of Pseudomonas savastanoi pv. рhaseolicola 4013 and P. syringae pv. tabaci 223. However, no stable isolates could be extracted from P. savastanoi pv. phaseolicola as the plages became inactive after a few passages on the bacterial culture. In order to overcome this, the phages were first cultured on P. syringae pv. tabaci before being transferred to P. savastanoi pv. рhaseolicola. The titers obtained were compared with phage titers from the original host bacteria. Thus, it was determined that the changes occuring in phages after their transfer to the Pseudomonas strain 4013 were irreversible. The changes were evaluated by comparing the effectiveness of phage culturing after a cycle of passages on strains 4013 and 223 where the phages were adapted to strain 4013 after being cultured on strain 223. Additionally, the effectiveness of phage culturing on strain 223 was also determined. The change in the effectiveness of phage culturing for the entire phage range suggests the presence of a defensive system in bacteria when the phages were transferred from strain 223 to strain 4013. The irreversibility of the changes occuring in phages was also tested and it was determined that phages 223/4 and 7591/2 adapt to original hosts and swiftly restore their original titers. Phage 7591/1, however, showed titers that were lower than the ones obtained from the original host culture. The testing of the irreversibility of changes in phages

Pest and disease resistance enhanced by heterologous suppression of a Nicotiana plumbaginifolia cytochrome P450 gene CYP72A2.

Science.gov (United States)

Smigocki, Ann C; Wilson, Dennis

2004-12-01

The functional role of the Nicotiana plumbaginifolia cytochrome P450 gene CYP72A2 was investigated in transgenic plants. N. tabacum plants transformed with a sense or antisense CYP72A2 construct exhibited diminished heights, branched stems, smaller leaves and deformed flowers. Western blot analysis revealed reduced levels of a 58 kDa protein corresponding to CYP72A2, suggesting that the CYP72A2 homolog was suppressed in the sense and antisense plants. Transgenic plants had increased resistance to Manduca sexta larvae that consumed about 35 to 90 less of transgenic versus control leaves. A virulent strain of Pseudomonas syringae pv. tabaci induced a disease-limiting response followed by a delayed and decreased development of disease symptoms in the transgenics. CYP72A2 gene mediated resistance suggests that the plant-pest or -pathogen interactions may have been modified by changes in bioactive metabolite pools.

Identification of unique volatile compounds associated with repelling whiteflies (Hemiptera: Aleyrodidae) in desert watermelon (Citrullus colocynthis)

Science.gov (United States)

Commercial watermelon cultivars (Citrullus lanatus var. lanatus) share a narrow genetic base and are susceptible to many insect pests and diseases. The insects include whiteflies which cause serious economic damages to this important cucurbit crop. However, several United States Plant Introduction a...

Ovary structure in a presocial insect, Elasmucha grisea (Heteroptera, Acanthosomatidae).

Science.gov (United States)

Ogorzałek, Antoni; Trochimczuk, Artur

2009-11-01

First generation egg clusters of Elasmucha grisea are more closely guarded than second generation clusters. The ovaries of this species are structured to enhance this behavior. The population of E. grisea from S-W Poland breeds in the spring (May-June) and late summer (July-August). The second generation clutches contain fewer eggs and are destroyed 3-4 days after oviposition by predators and parasitoids. The ovary structure in the studied species differs from that found in other Heteroptera. The average number of ovarioles per ovary is 24 while in the other investigated species the number of ovarioles per ovary is 6-7. Lateral oviducts are elongated and the ovarioles are arranged in a pennate pattern. Each ovariole contains only one growing ovarian follicle. Differentiation of the ovarioles and ovarian follicles is synchronised thus enabling simultaneous oviposition. A comparative analysis of the ovary structure during the life cycle, particularly the presence of atresive ovarian follicles in the ovarioles of egg- and nymph guarding females, as well as the shape and structure of the apical part of the tropharium all support the hypothesis of cooperation between females in E. grisea. A similar ovary structure has been observed in the Coccoidea (Hemiptera, Homoptera) which indicates presocial behavior.

Responses of prairie arthropod communities to fire and fertilizer: Balancing plant and arthropod conservation

Science.gov (United States)

Hartley, M.K.; Rogers, W.E.; Siemann, E.; Grace, J.

2007-01-01

Fire is an important tool for limiting woody plant invasions into prairies, but using fire management to maintain grassland plant communities may inadvertently reduce arthropod diversity. To test this, we established twenty-four 100 m2 plots in a tallgrass prairie in Galveston County, Texas, in spring 2000. Plots were assigned a fire (no burn, one time burn [2000], two time burn [2000, 2001]) and fertilization treatment (none, NPK addition) in a full factorial design. Fertilization treatments allowed us to examine the effects of fire at a different level of productivity. We measured plant cover by species and sampled arthropods with sweep nets during the 2001 growing season. Path analysis indicated that fertilization reduced while annual fires increased arthropod diversity via increases and decreases in woody plant abundance, respectively. There was no direct effect of fire on arthropod diversity or abundance. Diptera and Homoptera exhibited particularly strong positive responses to fires. Lepidoptera had a negative response to nutrient enrichment. Overall, the negative effects of fire on the arthropod community were minor in contrast to the strong positive indirect effects of small-scale burning on arthropod diversity if conservation of particular taxa is not a priority. The same fire regime that minimized woody plant invasion also maximized arthropod diversity.

With or without pheromone habituation: possible differences between insect orders?

Science.gov (United States)

Suckling, David Maxwell; Stringer, Lloyd D; Jiménez-Pérez, Alfredo; Walter, Gimme H; Sullivan, Nicola; El-Sayed, Ashraf M

2018-06-01

Habituation to sex pheromones is one of the key mechanisms in mating disruption, an insect control tactic. Male moths often show reduced sexual response after pre-exposure to female sex pheromone. Mating disruption is relatively rare in insect orders other than Lepidoptera. As a positive control we confirmed habituation in a moth (Epiphyas postvittana) using 24 h pre-exposure to sex pheromone to reduce subsequent activation behaviour. We then tested the impact of pre-exposure to sex or trail pheromone on subsequent behavioural response with insects from three other orders. Similar pre-exposure for 24 h to either sex pheromone [Pseudococcus calceolariae (Homoptera) and apple leaf curling midge Dasineura mali (Diptera), or trail pheromone of Argentine ants (Linepithema humile (Hymenoptera)], followed by behavioural assay in clean air provided no evidence of habituation after pre-exposure in these latter cases. The moths alone were affected by pre-exposure to pheromone. For pests without habituation, sustained attraction to a point source may make lure and kill more economical. Improved knowledge of behavioural processes should lead to better success in pest management and mechanisms should be investigated further to inform studies and practical efforts generally enhancing effectiveness of pheromone-based management. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Relative degree of susceptibility and resistance of different brassica campestris l. genotypes against aphid myzus persicae- a field investigation

International Nuclear Information System (INIS)

Sarwar, M.

2013-01-01

Field evaluation of twenty three Brassica campestris L. genotypes was conducted for aphid (Homoptera: Aphididae) resistance during 2008 crop season. The parameters used to assess tolerance of germplasm lines included pest population during growth season and grain yield at crop maturity. Aphids showed obvious preferences for all of the germplasm investigated; however, the evaluation for resistance to pest identified several genotypes with variable potential for tolerance and sensitivity. Estimated grain yield also varied significantly due to variable pest intensity noted, and seemed to be more appropriately dependent on the pest population conditions at the experimental site. Among the germplasm, the estimation obtained regarding both the parameters sorted out MM-II/02-3 and MM-I285 genotypes as most tolerant due to less pest infestation and damage. Peak infestations by aphid caused severe crop fatalities on S-9-S-97-0.75+75/55 and S-9-1006/95 genotypes, affecting the seed weight and resulting an immense reduction in grain Brassica genotypes appeared to be governed by means of varietals characteristics of diverse germplasms. The result of resistance test conducted under field environment is an effective and consistent approach in the practical selection of crop lines resistant or partially resistant to pests for use in future breeding programs. (author)

Comparison of the ionizing radiation effects on cochineal, annatto and turmeric natural dyes

International Nuclear Information System (INIS)

Cosentino, Helio M.; Takinami, Patricia Y.I.; Mastro, Nelida L. del

2016-01-01

As studies on radiation stability of food dyes are scarce, commercially important natural food grade dyes were evaluated in terms of their sensitivity against gamma ionizing radiation. Cochineal, annatto and turmeric dyes with suitable concentrations were subjected to increasing doses up to 32 kGy and analyzed by spectrophotometry and capillary electrophoresis. The results showed different pattern of absorbance versus absorbed dose for the three systems. Carmine, the glucosidal coloring matter from the scale insect Coccus cacti L., Homoptera (cochineal) remained almost unaffected by radiation up to doses of about 32 kGy (absorbance at 494 nm). Meanwhile, at that dose, a plant-derived product annatto or urucum (Bixa orellana L.) tincture presented a nearly 58% reduction in color intensity. Tincture of curcumin (diferuloylmethane) the active ingredient in the eastern spice turmeric (Curcuma longa) showed to be highly sensitive to radiation when diluted. These data shall be taken in account whenever food products containing these food colors were going to undergo radiation processing. - Highlights: • Comparison of radiosensitivity of food colors was performed. • Carmine showed the highest resistance to radiation. • Annatto and turmeric behaved sensitive to radiation when diluted. • Turmeric was the most affected by ionizing radiation.

Mechanisms of Oryza sativa (Poaceae) resistance to Tagosodes orizicolus (Homoptera: Delphacidae) under greenhouse condition in Venezuela.

Science.gov (United States)

González, Alex; Labrín, Natalia; Alvarez, Rosa M; Jayaro, Yorman; Gamboa, Carlos; Reyes, Edicta; Barrientos, Venancio

2012-03-01

Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the "Rice hoja blanca virus". During 2006-2007 we carried out research under greenhouse conditions at Fundaci6n Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundaci6n Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition). Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control 'Bluebonnet 50' was consistently susceptible across experiments and the resistant control 'Makalioka' had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and oviposition. The genotype 'FD0241-M-17-6-1-1-1-1' was identified with possible tolerance to the direct damage of sogata.

Mechanisms of Oryza sativa (Poaceae resistance to Tagosodes orizicolus (Homoptera: Delphacidae under greenhouse condition in Venezuela

Directory of Open Access Journals (Sweden)

Alex González

2012-03-01

Full Text Available Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the “Rice hoja blanca virus”. During 2006-2007 we carried out research under greenhouse conditions at Fundación Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundación Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition. Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control ‘Bluebonnet 50’ was consistently susceptible across experiments and the resistant control ‘Makalioka’ had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and viposition. The genotype ‘FD0241-M-17-6-1-1-1-1’ was identified with possible tolerance to the direct damage of sogata.Tagosodes orizicolus es una de las principales plagas del cultivo del arroz en América tropical causando dos tipos de daños a la planta, el directo, por efecto de la alimentación y oviposición; el indirecto, por la transmisión del virus de la hoja blanca del arroz. Durante el período 2006-2007 se llevó a cabo una investigación bajo condiciones de umbráculo en la Fundación Danac, Venezuela, con el objeto de determinar los mecanismos de resistencia de antixenosis, antibiosis y tolerancia a T. orizicolus que pudieran estar actuando en líneas avanzadas y cultivares del programa de mejoramiento enético de arroz de las instituciones INIA y Fundación Danac. Para la evaluación de antixenosis se utilizó el método de libre elección, para antibiosis (efecto sobre sobrevivencia y oviposición de los insectos el de alimentación forzada, adicionalmente se usó un método indirecto para estimar la tolerancia. Dentro de los principales parámetros determinados se encontraban: grado de daño, número de insectos posados sobre plantas de arroz, porcentaje de mortalidad de sogata en estado adulto, número de huevos y se calculó un índice de tolerancia con base en la biomasa. Los resultados mostraron que los genotipos de arroz evaluados poseen diferentes combinaciones en cuanto a los mecanismos de resistencia, así como el grado de su efecto. El testigo ‘Bluebonnet 50’ se mantuvo consistentemente susceptible en las evaluaciones y el testigo resistente ‘Makalioka’ fue el único genotipo que presentó alta antixenosis y alta antibiosis para sobrevivencia y oviposición. El resto de los genotipos presentaron un menor o mayor grado de resistencia de tipo antixenosis y antibiosis para sobrevivencia y oviposición. Se identificó el genotipo ‘FD0241-M-17-6-1-1-1-1’ con posible tolerancia al daño directo de sogata.

First results in the use of sterile insect technique against Trialeurodes vaporariorum (Homoptera: Aleyroididae) in greenhouses

International Nuclear Information System (INIS)

Calvitti, M.; Remotti, P.C.; Pasquali, A.; Cirio, U.

1998-01-01

Trials for the evaluation of the effectiveness of the sterile insect technique for the suppression of greenhouse whitefly, Trialeurodes vaporariorum (Westwood), both in cage and in greenhouse conditions are described. The results show a significant reduction of the reproductive capacity of the untreated whitefly populations interacting with sterile insects. Untreated whiteflies, co-existing in a mixed population together with sterile insects, attained less than the half (44%) of their potential reproductive capacity. This trend was also evident in the cage test where the untreated whitefly population, crossed with the sterile whiteflies, increased without exceeding 2/3 of the density recorded in the control cages. These results may be based on 2 joint sterile insect technique effects: primarily a drastic reduction of the progeny of normal untreated females, when mating with sterile males, carriers of dominant lethal mutations, and secondarily a progressive reduction of the females in the population due to an increasing rate of unsuccessful matings resulting in a condition of forced arrhenotoky. No deleterious effects, on plant health and fruit quality, were observed on plants exposed to high sterile whitefly pressures

Polyol specificity of recombinant Arabidopsis thaliana sorbitol dehydrogenase studied by enzyme kinetics and in silico modeling

Directory of Open Access Journals (Sweden)

María Francisca eAguayo

2015-02-01

Full Text Available Polyols are enzymatically-produced plant compounds which can act as compatible solutes during periods of abiotic stress. NAD+-dependent SORBITOL DEHYDROGENASE (SDH, E.C. 1.1.1.14 from Arabidopsis thaliana L. (AtSDH is capable of oxidizing several polyols including sorbitol, ribitol and xylitol. In the present study, enzymatic assays using recombinant AtSDH demonstrated a higher specificity constant for xylitol compared to sorbitol and ribitol, all of which are C2 (S and C4 (R polyols. Enzyme activity was reduced by preincubation with ethylenediaminetetraacetic acid (EDTA, indicating a requirement for zinc ions. In humans, it has been proposed that sorbitol becomes part of a pentahedric coordination sphere of the catalytic zinc during the reaction mechanism. In order to determine the validity of this pentahedric coordination model in a plant SDH, homology modeling and Molecular Dynamics simulations of AtSDH ternary complexes with the three polyols were performed using crystal structures of human and Bemisia argentifolii (Genn. (Hemiptera: Aleyrodidae SDHs as scaffolds. The results indicate that the differences in interaction with structural water molecules correlate very well with the observed enzymatic parameters, validate the proposed pentahedric coordination of the catalytic zinc ion in a plant SDH, and provide an explanation for why AtSDH shows a preference for polyols with a chirality of C2 (S and C4 (R.

Population Structure of the Greenhouse Whitefly, Trialeurodes vaporariorum (Westwood, an Invasive Species from the Americas, 60 Years after Invading China

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Rui-Rui Gao

2014-08-01

Full Text Available Though the greenhouse whitefly, Trialeurodes vaporariorum (Westwood (Hemiptera: Aleyrodidae was introduced into China more than 60 years ago, the genetic diversity and structure of this exotic insect pest and virus vector have not been studied. To investigate the population genetic characteristics of this invasive species and to identify potential invasion routes, the genetic diversity and population structure of 17 collections of T. vaporariorum from nine provinces in China were analyzed using seven microsatellite loci. The results of the analyses indicated that the genetic diversity for the populations examined from the four provinces: Jilin, Ningxia, Guizhou and Qinghai, was lower than the genetic diversity of populations from the five provinces: Yunnan, Shandong, Shanxi, Liaoning, and Gansu. The T. vaporariorum populations analyzed in this study grouped as two distinct genetic clusters based on the analysis using STRUCTURE, whereas, 8 clusters were identified based on the BAPS analysis. Of the 136 genetic distance (Fst values, 128 (94% were associated with a significant exact test. However, there was no significant relationship between Fst and geographical distance. These results demonstrate that populations of T. vaporariorum in China exhibit significant genetic differentiation, indicating the likelihood that multiple introductions of T. vaporariorum into China have occurred. Also, the populations collected from the provinces of Jilin, Ningxia, Guizhou and Qinghai appear to represent secondary introductions originating from other Chinese provinces.

Insetos indutores de galhas da porção sul da Cadeia do Espinhaço, Minas Gerais, Brasil Gall inducing insects from southern portion of the Espinhaço Range, Minas Gerais, Brazil

Directory of Open Access Journals (Sweden)

Marco Antonio A. Carneiro

2009-12-01

Full Text Available A riqueza de insetos galhadores é maior nas latitudes intermediárias em hábitats quentes e com vegetação esclerófila sob estresse hídrico e de nutrientes. Em regiões tropicais, os campos rupestres são indicados como hábitats ricos em espécies de insetos galhadores. Neste trabalho, foram descritas as galhas induzidas por insetos e suas plantas hospedeiras na porção sul da Cadeia do Espinhaço, sudeste do Brasil. Foram selecionados 60 sítios em seis regiões ao longo na porção sul da Cadeia do Espinhaço no estado de Minas Gerais. Em cada sítio 100 plantas foram amostradas totalizando 6.000 plantas censuradas ao longo de um gradiente altitudinal de 668 a 1860m. Foram encontrados 241 morfotipos de galhas em 142 espécies de plantas distribuídas em 29 famílias e de um total de 384 espécies de plantas amostradas. As famílias mais ricas em espécies de insetos galhadores foram Asteraceae (42%, principalmente espécies do gênero Baccharis. A maior parte das galhas (85% foi induzida por insetos da família Cecidomyiidae seguidos por Lepidoptera (4% e Homoptera (3%. Os ramos foram os órgãos mais freqüentemente atacados (72% enquanto que os morfotipos mais comuns foram o elíptico (37% e o globóide (36%. A espécie de planta hospedeira que apresentou mais morfotipos de galhas foi Baccharis pseudomyriocephala com 10 galhas distintas. Este estudo sustenta a afirmativa que campos rupestres apresentam uma elevada riqueza em espécies de insetos galhadores.Galling species richness is higher at intermediate latitudes on warm habitats and sclerophyllous vegetation under water and nutrient stress. In the tropical region, galling species richness is higher in rupestrian fields. Here the gall-inducing insects and their host plants of the southern portion of the Espinhaço range, southeastern Brazil are described. 60 study sites from six distinct regions along the Espinhaço range, at Minas Gerais state were selected. In each study site 100

Feeding by whiteflies suppresses downstream jasmonic acid signaling by eliciting salicylic acid signaling.

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Zhang, Peng-Jun; Li, Wei-Di; Huang, Fang; Zhang, Jin-Ming; Xu, Fang-Cheng; Lu, Yao-Bin

2013-05-01

Phloem-feeding whiteflies in the species complex Bemisia tabaci cause extensive crop damage worldwide. One of the reasons for their "success" is their ability to suppress the effectual jasmonic acid (JA) defenses of the host plant. However, little is understood about the mechanisms underlying whitefly suppression of JA-regulated defenses. Here, we showed that the expression of salicylic acid (SA)-responsive genes (EDS1 and PR1) in Arabidopsis thaliana was significantly enhanced during feeding by whitefly nymphs. Whereas upstream JA-responsive genes (LOX2 and OPR3) also were induced, the downstream JA-responsive gene (VSP1) was repressed, i.e., whiteflies only suppressed downstream JA signaling. Gene-expression analyses with various Arabidopsis mutants, including NahG, npr-1, ein2-1, and dde2-2, revealed that SA signaling plays a key role in the suppression of downstream JA defenses by whitefly feeding. Assays confirmed that SA activation enhanced whitefly performance by suppressing downstream JA defenses.

Interaksi Geminivirus pada Kejadian Inokulasi Ganda

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Sri Hendrastuti Hidayat

2005-07-01

Full Text Available Incidence of geminivirus infection has been caused severe losses on various economically important crops. This losses may cause by single infection or mix infection of several strain of geminiviruses. In this experiment we used two strain of geminiviruses, geminivirus infecting chillipepper from Segunung, West Java and geminivirus infecting tomato from Lembang, West Java (GVToL, to study the effect of geminivirus mix infection on the symptom expression and the capability of each strain to multiply in the host cell. Coefficient of dissimilarity between this two strain of geminiviruses is 7.5. When the two strain of geminiviruses was inoculated together to tomato plants by insect vector; Bemisia tabaci, the symptoms on infected plants is slightly different but less severe than those on plants inoculated with each strain separately. Detection with polymerase chain reaction (PCR followed by restriction enzyme digest of PCR product revealed that GVToL multiply better in the infected host cell.

Real-time PCR protocols for the quantification of the begomovirus tomato yellow leaf curl Sardinia virus in tomato plants and in its insect vector.

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Noris, Emanuela; Miozzi, Laura

2015-01-01

Tomato yellow leaf curl Sardinia virus (TYLCSV) (Geminiviridae) is an important pathogen, transmitted by the whitefly Bemisia tabaci, that severely affects the tomato production in the Mediterranean basin. Here, we describe real-time PCR protocols suitable for relative and absolute quantification of TYLCSV in tomato plants and in whitefly extracts. Using primers and probe specifically designed for TYLCSV, the protocols for relative quantification allow to compare the amount of TYLCSV present in different plant or whitefly samples, normalized to the amount of DNA present in each sample using endogenous tomato or Bemisia genes as internal references. The absolute quantification protocol allows to calculate the number of genomic units of TYLCSV over the genomic units of the plant host (tomato), with a sensitivity of as few as ten viral genome copies per sample. The described protocols are potentially suitable for several applications, such as plant breeding for resistance, analysis of virus replication, and virus-vector interaction studies.

Acanthaleyrodes elevatus sp. n. (Hemiptera: Aleyrodidae) from India, with key to species and discussion of tuberculate setae.

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Dubey, Anil Kumar; Singh, Sudhir; Martin, Jon H

2014-11-03

The genus Acanthaleyrodes Takahashi is reported for the first time from India. Acanthaleyrodes elevatus sp. n. is described from Bridelia retusa in Kerala, India, with a key to puparia of Acanthaleydes species. The new species differs in its exceptionally elevated eighth abdominal tergite, circular vasiform orifice and eight pairs of subdorsal setae. The generic characteristics of Acanthaleyrodes are redefined and distinguished from those of Tuberaleyrodes Takahashi. A. styraci Takahashi is re-described in detail with illustrations of puparia and immatures from Hong Kong. A lectotype puparium is designated for A. callicarpae Takahashi. The development of tuberculate setae is discussed, in whitefly puparia and earlier nymphal instars, and considered to be subject to environmental modification.

Plan de muestreo directo para Trialeurodes vaporariorum (Westwood (Hemiptera: Aleyrodidae en cultivos comerciales de tomate

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Bernal Liliana

2008-08-01

Full Text Available

Los daños ocasionados por Trialeurodes vaporariorum generan pérdidas económicas que disminuyen la producción y pueden contribuir en el alza de los precios del tomate. Para su control se acude a aplicaciones continuas de insecticidas, sin obtener resultados satisfactorios. Como alternativa de control se realizan liberaciones del parasitoide E. formosa. Sin embargo, el éxito de este sistema implica estimar la densidad de la plaga a través de un método de muestreo adecuado. Por ello, se estandarizó un plan de muestreo directo, económicamente viable, para ninfas de mosca blanca en un cultivo comercial de tomate bajo invernadero. Se determinó la incidencia de prácticas de manejo y de la fenología en la distribución espacial de ninfas. En términos generales, el muestreo se dividió en tres etapas: 1 muestreo totalmente aleatorio, entre las 5 y 7 semanas después de la siembra (sds, para plantas no divididas en tercios; 2 muestreo aleatorio, entre las 8 y 16 sds, los conteos se realizaron en hojas del tercio inferior; 3 muestreo bietápico: planta y hoja, entre las 17 y 24 sds, los conteos se efectuaron sobre hojas de los tercios medio y superior. Se encontró que prácticas culturales como el despunte influyeron en la distribución espacial de las ninfas. La implementación del muestreo directo generó un incremento en la producción del 0,06% y permitió estimar la densidad de ninfas de Trialeurodes vaporariorum en el cultivo (con precisiones de 5%, 10% y 25% como criterio para liberar E. formosa.

Performance of novel vs traditional insecticides for the control of amrascs biguttula biguttula (homoptera, cicadellidae) on cotton

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Karar, H.; Babar, T.K.; Shahzad, F.; Saleem, M.; Ali, A.; Akram, M.

2013-01-01

Amrasca biguttula biguttula (ishida) can reduce the yield of cotton approximately 25%. no potential predators have been recorded in the field for its control. to overcome this pest insecticides play significant role in the improvement of crop yields all over the world during the last four to five decades. to save the crop from this notorious pest, ten formulations of insecticides viz., acephate 75sp (acephate) at the rate 625g, imidacloprid 25wp (imidacloprid) at the rate188g, thiamethaxim 25wg (actara) at the rate 60g, imidacloprid 70wg (confidor) at the rate 43g, dimethoat e 40ec (sanitox) at the rate 1000 ml, nytonpyron 10sl (pyramid) at the rate 500ml, lambdacyhlothrin 2.5e (kango) at the rate 825 ml, thiachloprid 480sc (talent) at the rate 63 ml, imidacloprid 25sl (confidor) at the rate 500ml, and diafenthiuron 500sc (polo), at the rate 500ml, per hectare were sprayed in the field having maximum population of nymphs and adults of jassid at cotton research station, multan on cotton variety bt-886 in the month of july, 2011 and 2012. the maximum mortality of Jassid was observed in those treatments, where acephate was applied with 79, 72, 65 mortality, nytonpyron with 69, 63, 55 and imidacloprid 68, 63, 57 percent mortality after 24, 72 and 168 h of spray. minimum mortality of jassid was observed in the treatments where talent was applied having 25, 17 and 16 percent mortality 24, 72 and 168 h after spray. By the application of acephate, pyramid and confidor 25sl on cotton crop the yield can be increased. (author)

Pear transformed with a lytic peptide gene for disease control affects nontarget organism, pear psylla (Homoptera: Psyllidae).

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Puterka, Gary J; Bocchetti, Chris; Dang, Phat; Bell, R L; Scorza, Ralph

2002-08-01

The biology and behavior of pear psylla, Cacopsylla pyricola Foerster, on a transgenic clone of 'Bartlett' pear, Pyrus communis L., containing a synthetic antimicrobial gene, D5C1, was compared with that of a nontransgenic parental clone to determine whether there were any nontarget effects. The gene construct also contained the marker gene nptII (aminoglycoside 3'-phosphotransferase II) that encodes for antibiotic resistance to identify transformed plants. The purpose of the original transformation was to enhance pear resistance to the bacterial disease fireblight caused by Erwinia amylovora (Burr.) Winslow et al. The biology and behavior of pear psylla on a transgenic clone were compared with a nontransgenic parental pear clone in short- (crops.

A new genus and new species of felt scales (Homoptera: Coccinea: Eriococcidae from Tierra del Fuego (Chile

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Ilya A. Gavrilov-Zimin

2016-10-01

Full Text Available Telmatococcus igniumterrae gen. nov. et sp. nov. is described and illustrated based on the material collected from a sphagnum bog in the extreme southern part of South America (Tierra del Fuego. The new monotypic genus differs from all known genera of Eriococcidae in having short cylindrical truncated setae of the anal apparatus and pouches with numerous quinquelocular pores near the anal apparatus. The habitat of the new taxon is characterized.

Buprofezin susceptibility survey, resistance selection and preliminary determination of the resistance mechanism in Nilaparvata lugens (Homoptera: Delphacidae).

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Wang, Yanhua; Gao, Congfen; Xu, Zhiping; Zhu, Yu Cheng; Zhang, Jiushuang; Li, Wenhong; Dai, Dejiang; Lin, Youwei; Zhou, Weijun; Shen, Jinliang

2008-10-01

Buprofezin has been used for many years to control Nilaparvata lugens (Stål). Assessment of susceptibility change in the insect is essential for maintaining control efficiency and resistance management. Eleven-year surveys showed that most field populations were susceptible before 2004. However, substantially higher levels of resistance (up to 28-fold) were found in most of the rice fields in China after 2004. A field population was collected and periodically selected for buprofezin resistance in the laboratory. After 65 generations (56 were selected), the colony successfully obtained 3599-fold resistance to buprofezin. Synergism tests showed that O,O-diethyl-O-phenyl phosphorothioate (SV1), piperonyl butoxide (PBO) and diethyl maleate (DEM) increased buprofezin toxicity in the resistant strain by only 1.5-1.6 fold, suggesting that esterases, P450-monooxygenases and glutathione S-transferases had no substantial effect on buprofezin resistance development. The results from this study indicate that N. lugens has the potential to develop high resistance to buprofezin. A resistance management program with rotation of buprofezin and other pesticides may efficiently delay or slow down resistance development in the insect. Further investigation is also necessary to understand the resistance mechanisms in N. lugens.

Bacterial symbionts, Buchnera, and starvation on wing dimorphism in English grain aphid, Sitobion avenae (F. (Homoptera: Aphididae

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Fangmei eZhang

2015-05-01

Full Text Available Wing dimorphism in aphids can be affected by multiple cues, including both biotic (nutrition, crowding, interspecific interactions, the presence of natural enemies, maternal and transgenerational effects, and alarm pheromone and abiotic factors (temperature, humidity, and photoperiod. The majority of the phloem-feeding aphids carry Buchnera, an obligate symbiotic proteobacteria. Buchnera has a highly reduced genome size, but encode key enzymes in the tryptophan biosynthetic pathway and is crucial for nutritional balance, development and reproduction in aphids. In this study, we investigated the impact of two nutritional-based biotic factors, symbionts and starvation, on the wing dimorphism in the English grain aphid, Sitobion avenae, a devastating insect pest of cereal crops (e.g., wheat worldwide. Elimination of Buchnera using the antibiotic rifampicin significantly reduced the formation of winged morphs, body mass and fecundity in S. avenae. Furthermore, the absence of this primary endosymbiont may disrupt the nutrient acquisition in aphids and alter transgenerational phenotypic expression. Similarly, both survival rate and the formation of winged morphs were substantially reduced after neonatal (< 24h old offspring were starved for a period of time. The combined results shed light on the impact of two nutritional-based biotic factors on the phenotypic plasticity in aphids. A better understanding of the wing dimorphism in aphids will provide the theoretical basis for the prediction and integrated management of these phloem-feeding insect pests.

Varietals resistance and susceptibility in mustard (brassica campestris l.) genotypes against aphid myzus persicae (sulzer) (homoptera: aphididae)

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Sarwar, M.; Ahmad, N.; Khan, G.Z.; Tofique, M.

2009-01-01

The exploitation of resistant cultivars is an imperative, simple, practical and flexible way to cope with insect pests incidence. Thirty genotypes of mustard (Brassica campestris L.) were tested for their resistance and susceptibility to aphid Myzus persicae (Sulzer) exposed under natural field conditions. Data on pest tolerance of genotypes were judged by quantitative traits such as number of aphids on each infested plant and mean dry weight of seeds per genotype. Studies observed the discrepancy in overall rates of pest invasion and seed yield contained by trailed mustard genotypes. Agati sarson (P), S-9-S-97-100/45 and S-9-S-97-100/45 were the least damaged genotypes showing their moderate resistance. Amongst other genotypes, MM-I/01-5, MM-I285 and MM-I/01-6 were the most damaged showing oversensitive response. Although the majority of genotypes were found vulnerable to pest, Agati sarson (P) and S-9-S-97-100/45 due to their lowest hypersensitive response toward aphid contamination and increased pods yield could be used for the development of essential resistance in mustard plant. A marked mode of damage inflicted by aphid on the crop was noticed and the abiotic factors contributing variations in aphid infestation levels during both growing seasons were determined. Knowledge about the host plant resistance investigated can facilitate growers to choose the most appropriate cultivars as pest control strategy. (author)

Interplant movement and spatial distribution of alate and apterous morphs of Nasonovia ribisnigri (Homoptera: Aphididae) on lettuce.

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Diaz, B M; Barrios, L; Fereres, A

2012-08-01

Knowledge on colonization modes and interplant movement of Nasonovia ribisnigri can contribute to the development of optimal control of this pest. The aim of this study was to determine the spatio-temporal distribution and the mode of spread between adult morphs of Nasonovia ribisnigri, comparing spring and autumn lettuce protected crops. The spatial and temporal pattern was analyzed using the spatial analysis by distance indices (SADIE) methodology and other related displacement indices. The population size of N. ribisnigri was greater in the autumn than in the spring growing seasons due to milder temperatures. The percentage of plants colonized by aphids was higher in spring than in autumn, showing the great dispersal potential of this aphid species independent of their population size. Differential propensity for initial displacement from the central plant was observed between adult morphs in spring, resulting in a greater ability of apterous than alate aphids to spread far away from the source plant. In autumn, both adult morphs showed an initial reduced displacement; however, the number of plants infested (≈20%) with at least one aphid at this initial time (seven days) was similar for both adult morphs and both growing seasons. Analysis of the spatial pattern of both adult morphs revealed a predominantly random distribution for both spring and autumn trials. This pattern was achieved by a prevalent random movement over the area (γ≈0.5). These results highlight the ability of the apterous N. ribisnigri to spread within greenhouse lettuce crops early in the spring, suggesting that detection of the pest by deep visual inspection is required after lettuce emergence.

Efecto de la configuración de lotes de gramíneas invernales sobre poblaciones de Delphacidae (Insecta: Homoptera en dispersión The effect of the configuration of winter grass plots on dispersing populations of Delphacidae (Insecta: Homoptera

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M.A. Bruno

2007-12-01

Full Text Available Las características del paisaje afectan la distribución y abundancia de los insectos dentro y entre los lotes de cultivos. El objetivo de este trabajo fue determinar el efecto de los elementos del paisaje agrícola sobre la abundancia de los individuos en dispersión de las especies de Delphacidae. Éstas son vectores de virus patogénicos que transmiten enfermedades de importancia económica para la producción agropecuaria. El estudio se realizó en el área central de la provincia de Córdoba, Argentina; los insectos fueron capturados con trampas pegajosas ubicadas dentro de parches de hospedadores. Las métricas del paisaje analizadas fueron: área del parche, índice de proximidad media y porcentaje del paisaje cubierto por parches de una clase de hospedador. La abundancia de Delphacodes kuscheli tuvo relación positiva con el área de los parches de pasturas de invierno. El índice de proximidad media tuvo relación positiva con las abundancias de D. kuscheli y D . balboae en los parches de pasturas de invierno y el porcentaje del paisaje cubierto con parches de pasturas de invierno se relacionó positivamente con las abundancias de D. kuscheli, D. balboae y D. haywardi. Las abundancias de Toya propincua no mostraron relación con ninguna de las métricas del paisaje analizadas.Landscape configuration can affect the distribution and abundance of insect species. The objective of this work was to determine the effect of landscape elements configuration on the abundance of dispersing individuals of Delphacidae species. Delphacid species are important vectors of pathogenic viruses causing diseases of economic importance on grain production. The study was performed in the central area of Córdoba Province, Argentina; the insects were collected with sticky traps placed in plant host patches. The landscape metrics estimated were: host patch area, Mean Proximity Index (MPI and the Percentage of Landscape occupied (PLAND by host patches of the same class. The abundance of Delphacodes kuscheli showed a positive relationship with patch area of the winter pastures. There was a positive relationship between Mean Proximity Index of winter pastures patches and D. kuscheli and D . balboae abundances. The Percentage of Landscape occupied by the winter pastures patches also showed a positive relationship with Delphacodes kuscheli, Delphacodes balboae and Delphacodes haywardi abundances. Finally we found no relationship between Toya propinqua abundance and any of the landscape metrics analyzed in this work. These results show that landscape configuration has a different effect on the dispersing population of the different species of Delphacidae.

For the Aphid fauna in the territory of Yenisei river basin. Communication 1. Aphids on coniferous plants

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A. V. Gurov

2016-02-01

Full Text Available The paper reports on new and previously not well-known data on insufficiently studied fauna of aphids living on coniferous trees in Central Siberia of the basin of Yenisei river. This region is the extensive transect of latitudinal geographic zones from semi-desert in the South to the arctic deserts in the North. That is why this region is very peculiar. This is the reason for insufficient study of regional entomological fauna. Aphids (Homoptera: Aphidoideaare a very taxonomically and ecologically heterogeneous group of insects. The aphids living on conifer trees are notstudied completely on the territory of Yenisei basin. Due to this, the studying of not well-known and economicallyimportant aphids is actual. For example, the insufficient study of regional aphids is confirmed by the fact, that duringthree weeks only of the work for INTAS-94-0930 Project two new aphid species were found and described on thisterritory. Also, the new species of family Mindaridae, which was described in Mongolia in 1980, was found in Siberiafor the first time. These finds indicate the real possibility to describe an interesting conifer aphid complex in the absolutely unstudied forested territory between Angara and Lower Tunguska rivers. Geographical location, dates ofcollection and feeding preferences of different species are described. A general review of Yenisei basin Siberian aphidfauna is suggested for the first time ever.

Presence of the aphid, Chaetosiphon fragaefolii, on strawberry in Argentina.

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Cédola, Claudia; Grecob, Nancy

2010-01-01

Seasonal abundance of the strawberry aphid complex under different agronomic practices in the outskirts of La Plata, Argentina was studied on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae). Aphid densities were low in strawberry fields in which insecticides and fungicides were used. In addition to Aphis gossypii, Aphis fabae, Mysus persicae and Macrosiphum euphorbiae, the aphid, Chaetosiphon fragaefolii (Cockerell) (Homoptera: Aphididae), was recorded for the first time in this horticultural area. Life history and some demographic parameters were calculated for C. fragaefolii. The mean duration of nymphal stages was 10.44 days, the oviposition period was 11.8 days, and the mean number of nymph/female/day was 2.4 +/- 0.3. Demographic parameters analyzed included the net reproductive rate R(o) = 14.55 +/- 0.096 nymph/female, generation time T=16.91 +/- 0.035 days, and the intrinsic rate of increase r(m) = 0.158 +/- (0.004). No parasites were found associated with C. fragaefolli. The pathogenic fungus, Entomophthora planchoniana Cornu (Zygomycetes: Entomophthorales) was the main mortality factor. Although aphids are not the main pests in strawberry fields, C. fragaefolii can be a serious problem because it can transmit several virus diseases of strawberry. Greater knowledge of life history traits and mortality factors of this species is needed in order to design appropriate control strategies.

ON THE PALEOFAUNA INVERTEBRATES (MOLLUSCA, ARTROPODA; INSECTA OF DIATOMITE DEPOSITS OF SHAMB–1 LOCALITY (SISIAN SUITE, EARLY PLEISTOCENE, ARMENIA

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М. A. Маrjanyan

2016-01-01

Full Text Available Aim. The study of fossil insects from diatomaceous sediments of Shamb-1 locality of Sisian Suite (Early Pleistocene. The collection of fossils plants and animals of Institute of Botany of NAS RA and authors' findings served as material for study.Methods. The material is processed and prepared for study by conventional methods in paleontology for prints and fossils of insects from diatomaceous sediments. There are 654 samples studied: 2 samples were with mollusks’ imprints and 652 samples with imprints of insects, from which preserved marks on 291samples allowed to identify them up to order, family, genus and species.Results. The studied material refers to the Mollusca and Arthropoda (Insecta types. Insects are represented by species of orders Orthoptera (2 fam., Homoptera (1 fam., Heteroptera (2 fam., Coleoptera (15 fam., Hymenoptera (2 fam., Diptera (1 fam.. Coleopteras dominate among them and are presented with following species of the family – Carabidae, Dytiscidae, Hydrophilidae, Histeridae, Staphylinidae, Silphidae, Elateridae, Buprestidae, Lampyridae, Scarabaeidae, Chrysomelidae, Tenebrionidae, Coccinellidae, Cerambycidae, Curculionidae.Main conclusions. An analysis of the taxonomic composition of paleofauna was done, which corresponds to the recent fauna and with considering modern ecological characteristics of systematical groups and species. In the investigated location of Shamb-1 a version is suggested about the palaeolandscapes and palaeoclimate in the Early Pleistocene.

Hairy nightshade as a potential Potato leafroll virus (Luteoviridae: Polerovirus) inoculum source in Pacific Northwest potato ecosystems.

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Srinivasan, R; Alvarez, J M

2008-09-01

Hairy nightshade, Solanum sarrachoides, is a solanaceous weed found abundantly in Pacific Northwest potato ecosystems. It serves as a reservoir for one of the important potato viruses, Potato leafroll virus (PLRV) (Luteoviridae: Polerovirus), and its most important vector, the green peach aphid, Myzus persicae (Homoptera: Aphididae). Laboratory research indicated an increased green peach aphid settling and performance on S. sarrachoides than on potato. It also revealed that green peach aphids transmitted PLRV more efficiently from S. sarrachoides to potato than from potato to potato. To test the efficiency of S. sarrachoides as an inoculum source in the field, a two season (2004 and 2005) trial was conducted at Kimberly, Idaho. Two inoculum sources, PLRV-infected potato and PLRV-infected S. sarrachoides, were compared in this trial. Green peach aphid density and temporal and spatial PLRV spread were monitored at weekly intervals. Higher densities of green peach aphids were observed on plots with S. sarrachoides and inoculum sources (PLRV-infected S. sarrachoides and potato) than on plots without S. sarrachoides and inoculum sources. PLRV infection in plots with PLRV-infected S. sarrachoides was similar to or slightly higher than in plots with PLRV-infected potato as an inoculum source. Temporal and spatial PLRV spread was similar in plots with either inoculum source. Thus, S. sarrachoides is as efficient as or a better PLRV inoculum source than potato.

The invasive MED/Q Bemisia tabaci genome: a tale of gene loss and gene gain

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Whiteflies are a group of invasive crop pests that impact global agriculture. An analysis was conducted to compare draft genomes of two whitefly strains, which demonstrated the relative conserved gene order, but a number of genes were either novel (added) or omitted (deleted) between genomes. This...

Membracidos de Colombia - I. Revisión parcial de las especies del género Alchisme Kirkaldy (Homoptera: Membracidae: Hoplophorioninae Membracidos de Colombia - I. Revisión parcial de las especies del género Alchisme Kirkaldy (Homoptera: Membracidae: Hoplophorioninae

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Restrepo Mejía Ruben

1980-09-01

Full Text Available Se revisó el género Alchisme Kirkaldy. De las diecinueve especies anotadas por Metcalf (1965 no se obtuvieron especímenes de A. apicalis (Walker, A. costaricensis Goding, A. elevata Goding, A. laticornis Funkhouser, A. pinguicornisFunkhouser, A. recurva (Stäl, A. spinosa Funkhouser y A. truncaticornis (Germar. Se incluyen las descripciones originales de estas especies y tentativamente se localizan en la clave presentada. Se redescriben: A. bos (Fairmaire, A. fastidiosa (Fairmaire, A. grossa (Fairmaire, A. inermis (Fairmaire, A. nigrocarinata (Fairmaire, A. rubrocostata (Spinola, A. turrita (Germar, A. ustulata (Fairmaire, A. virescens (Fairmaire y A. nigrocarinata var. tridentata (Fairmaire, para la cual se usa su combinación original A. tridentata (Fairmaire. Se sinonimizóa A. projecta Funkhouser en favor de A. bos (Fairmaire.Se ilustran las principales características del pronoto y de los genitales de los machos; se observaron y se obtuvieron fotografías de los edeagos en un microscopio electrónico "rastreador" (Scanning Electro Microscope, las cualesse incluyen como parte de las ilustraciones. Se analizó la distribución geográfica del género y se ilustró por medio de mapas.The genus Alchisme Kirkaldy was revised. From nineteen species listed by Metcalf (1965 not specimens were obtained of eight of them. Original descriptions of these species are included and tentatively are localized in the key.  A redescription is given for the species A. bos (Fairmaire, A. fastidiosa (Fairmaire, A. grossa (Fairmaire, A. inermis (Fairmaire, A. nigrocarinata (Fairmaire, A. rubrocostata (Spinola, A. turrita (Germar, A. ustulata (Fairmaire, A. virescens (Fairmaire y A. nigrocarinata var. tridentata (Fairmaire, for which was used the original combination A. tridentata (Fairmaire. A. projecta Funkhouser was synonymized in A. bos (Fairmaire. The main pronotum characters and male genitalia are illustred; Scanning Electro Microscope pictures of the aedeagus of the insects were observed and obtained and are included as part of the illustrations. Geographic distributionsof the genus was analized and maps were prepared.

First record of Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae severely damaging field grown potato crops in South Sulawesi, Indonesia

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Nasruddin Andi

2016-04-01

Full Text Available Greenhouse whitefly, Trialeurodes vaporariorum Westwood was reported for the first time in the South Sulawesi Province of Indonesia, and is causing significant damage to field grown potato crops. In an insecticide trial, the tuber yield in infested, untreated plants was reduced by 39%, and the plants had an average number of 68 adult whiteflies per leaflet.

Life-history parameters of Encarsia formosa, Eretmocerus eremicus and E. Mundus, aphelinid parasitoids of Bemisia argentifolii (Hemiptera: Aleyrodidae)

NARCIS (Netherlands)

Qiu, Y.T.; Lenteren, van J.C.; Drost, Y.C.; Posthuma-Doodeman, J.A.M.

2004-01-01

Life-history parameters (juvenile development time, adult longevity, host instar preference and rate of parasitism) offour parasitoids of Bemisia argentifolii (two strains of Encarsia formosa (D and B), Eretmocerus eremicus and Eretmocerus mundus) Were Studied in the laboratory. At 15degreesC

Complete nucleotide sequences of a new bipartite begomovirus from Malvastrum sp. plants with bright yellow mosaic symptoms in South Texas.

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Alabi, Olufemi J; Villegas, Cecilia; Gregg, Lori; Murray, K Daniel

2016-06-01

Two isolates of a novel bipartite begomovirus, tentatively named malvastrum bright yellow mosaic virus (MaBYMV), were molecularly characterized from naturally infected plants of the genus Malvastrum showing bright yellow mosaic disease symptoms in South Texas. Six complete DNA-A and five DNA-B genome sequences of MaBYMV obtained from the isolates ranged in length from 2,608 to 2,609 nucleotides (nt) and 2,578 to 2,605 nt, respectively. Both genome segments shared a 178- to 180-nt common region. In pairwise comparisons, the complete DNA-A and DNA-B sequences of MaBYMV were most similar (87-88 % and 79-81 % identity, respectively) and phylogenetically related to the corresponding sequences of sida mosaic Sinaloa virus-[MX-Gua-06]. Further analysis revealed that MaBYMV is a putative recombinant virus, thus supporting the notion that malvaceous hosts may be influencing the evolution of several begomoviruses. The design of new diagnostic primers enabled the detection of MaBYMV in cohorts of Bemisia tabaci collected from symptomatic Malvastrum sp. plants, thus implicating whiteflies as potential vectors of the virus.

New developments in insecticide resistance in the glasshouse whitefly (Trialeurodes vaporariorum) and the two-spotted spider mite (Tetranychus urticae) in the UK.

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Gorman, Kevin; Hewitt, Fiona; Denholm, Ian; Devine, Gregor J

2002-02-01

A recent survey of insecticide resistance in two of the most problematic pests in UK glasshouses revealed some new developments. At least some individuals in all UK samples of Trialeurodes vaporariorum that were tested resisted the insect growth regulator (IGR) buprofezin. The most strongly resistant strains were unaffected by the field application rate of this compound, and even samples from populations that had never been exposed to buprofezin contained individuals that survived the highest concentration applied (10,000 mg litre-1). The field rate of buprofezin was shown to select for resistance through vapour action alone. The benzophenylurea teflubenzuron, an unrelated IGR, was cross-resisted by buprofezin-resistant individuals. There was no evidence of resistance to imidacloprid, but all T vaporariorum strains tested, regardless of origin, exhibited a high innate tolerance to nicotine, when compared with another whitefly species, Bemisia tabaci. Marked resistance to fenbutatin oxide and tebufenpyrad was found in single glasshouse populations of Tetranychus urticae, but these compounds and abamectin appeared to remain highly effective against all other strains collected.

Inheritance Mode and Realized Heritability of Resistance to Imidacloprid in the Brown Planthopper, Nilaparvata lugens (Stal) (Homoptera: Delphacidae)

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BACKGROUND: The brown planthopper, Nilaparvata lugens (Stål) is a serious pest which causes enormous losses to the rice crop in Asia. The genetic basis of imidacloprid resistance was investigated in N. lugens. RESULTS: The resistant strain, selected for imidacloprid resistance from a laboratory pop...

Insecticide susceptibility of the green plant bug, Apolygus lucorum Meyer-Dür (Homoptera: Miridae and two predatory arthropods

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Zhang Zhengqun

2015-12-01

Full Text Available The green plant bug (Apolygus lucorum Meyer-Dür is a key pest of Bt cotton in China. Along with biological control, chemical control is one of the most important strategies in A. lucorum Integrated Pest Management (IPM. The goal of this study was to evaluate the toxicity of eight conventional insecticides to A. lucorum and to assess the susceptibility of two generalist predators Chrysopa sinica (Jieder and Propylaea japonica (Thunbery to insecticides that are commonly used in A. lucorum management. Via glass-vial and leaf-dip bioassay, toxicity tests with selected insecticides at two different life-stages of A. lucorum indicated significant differences between the LD50 or LC50 values for these compounds within different insecticidal classes. Phenylpyrazole fipronil had the highest toxicity to 4th-instar nymphs and adults of A. lucorum, whereas neonicotinoid imidacloprid had the lowest toxicity among the insecticides. Females were more tolerant to insecticides than were males, as shown by the higher LD50 values for females. Furthermore, laboratory tests showed that endosulfan had the highest selectivity to C. sinica and P. japonica: the selective toxicity ratios (STRs were superior to other tested insecticides, particularly imidacloprid, and were 5.396 and 4.749-fold higher than baseline STRs, respectively. From this study, we conclude that fipronil can potentially be used to efficiently control A. lucorum. An alternative control agent worth consideration is endosulfan, owing to its relative safety to non-targeted natural enemies.

A Tomato necrotic dwarf virus isolate from Datura with poor transmissibility by the whitefly, Bemisia tabaci

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Tomato necrotic dwarf virus (ToNDV); genus Torradovirus, is a whitefly-transmitted virus that caused significant losses for tomato production in the Imperial Valley of California during the 1980s. The virus causes severe stunting, dwarfing of leaves, foliar and fruit necrosis, and greatly reduced f...

The Effects of Dispersal and Predator Density on Prey Survival in an Insect-Red Clover Metacommunity.

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Stasek, David J; Radl, James N; Crist, Thomas O

2018-01-01

Trophic interactions are often studied within habitat patches, but among-patch dispersal of individuals may influence local patch dynamics. Metacommunity concepts incorporate the effects of dispersal on local and community dynamics. There are few experimental tests of metacommunity theory using insects compared to those conducted in microbial microcosms. Using connected experimental mesocosms, we varied the density of the leafhopper Agallia constricta Van Duzee (Homoptera: Cicadellidae) and a generalist insect predator, the damsel bug (Nabis spp., Heteroptera: Nabidae), to determine the effects of conspecific and predator density and varying the time available to dispersal among mesocosms on predation rates, dispersal rates, and leafhopper survival. Conspecific and damsel bug density did not affect dispersal rates in leafhoppers, but this may be due to leafhoppers' aversion to leaving the host plants or the connecting tubes between mesocosms hindering leafhopper movement. Leafhopper dispersal was higher in high-dispersal treatments. Survival rates of A. constricta were also lowest in treatments where dispersal was not limited. This is one of the first experimental studies to vary predator density and the time available to dispersal. Our results indicate that dispersal is the key to understanding short-term processes such as prey survival in predator-prey metacommunities. Further work is needed to determine how dispersal rates influence persistence of communities in multigenerational studies. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Mutualisme pucerons – fourmis : étude des bénéfices retirés par les colonies d'Aphis fabae en milieu extérieur

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Verheggen F.

2009-01-01

Full Text Available Aphid – ant mutualism: an outdoor study of the benefits for Aphis fabae. Aphid – ant relationships are common examples of mutualism. Aphids are indeed submitted to predation and therefore require protection, while ants are continuously looking for new sugar sources. The present work aimed to study the benefits that a mutualistic relationship with Lasius niger (Hymenoptera, Formicidae could bring to the black bean aphid Aphis fabae (Homoptera, Aphididae. Several parameters were observed in the field, on broad bean plants infested with an initial amount of 100 A. fabae and in presence or not of a L. niger colony. More aphids were observed on plants being visited by ants as well as a higher proportion of winged individuals. One explanation is that fewer predators were observed on plants being visited by ants, demonstrating their protective role. However, the number of parasitized aphids was not reduced in presence of L. niger. On the other hand, fewer different aphid species were present on plants foraged by ants, what suggests that they could exert a predation on unattended aphids. Our observations do not allow to conclude on any impact of L. niger on the fitness of the aphid host plant, although fewer exuvia and honeydew spots were observed when they were present. All these results confirm that L. niger increase the fitness of A. fabae colonies mainly by decreasing the number of predators and by reducing competition from aphid species unattended by ants.

Analysis of the feeding habits of the swallow-tailed hummingbird, Eupetomena macroura (Gmelin, 1788, in an urban park in southeastern Brazil

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MCB. Toledo

Full Text Available The aim of this work was to observe and describe the feeding habits and available food resources of the swallow-tailed hummingbird, Eupetomena macroura. The study was carried out in a municipal park located in the city of Taubaté, in the state of São Paulo. The observations took place between December 2003 and October 2004, recording the following variables: 1 the plant species visited for feeding and territorial defense; 2 the kinds of food resources; and 3 the kinds of flight to procure and obtain food. E. macroura visited 12 plant species. For territorial defense, Mangifera indica was the most visited, whereas Malvaviscus arboreus was most visited for feeding. The foliage was the plant part that received the most frequent visits. In order to obtain nectar, the only species visited was M. arboreus; to obtain arthropods, the species most visited were Mangifera indica and Hymenaea stilbocarpa. In the dry season, the hummingbirds visited flowers, whereas in the rainy season they visited leaves to acquire food. The arthropod groups most frequently found on leafy branches were Homoptera and Psocoptera. Finally, the results of the type of flight analysis showed that flight used to capture food was more often observed than were flights to search for food. In conclusion, these observations suggest that E. macroura shows plasticity in feeding behavior, which can help it to persist in urban areas.

New views on strand asymmetry in insect mitochondrial genomes.

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Shu-Jun Wei

Full Text Available Strand asymmetry in nucleotide composition is a remarkable feature of animal mitochondrial genomes. Understanding the mutation processes that shape strand asymmetry is essential for comprehensive knowledge of genome evolution, demographical population history and accurate phylogenetic inference. Previous studies found that the relative contributions of different substitution types to strand asymmetry are associated with replication alone or both replication and transcription. However, the relative contributions of replication and transcription to strand asymmetry remain unclear. Here we conducted a broad survey of strand asymmetry across 120 insect mitochondrial genomes, with special reference to the correlation between the signs of skew values and replication orientation/gene direction. The results show that the sign of GC skew on entire mitochondrial genomes is reversed in all species of three distantly related families of insects, Philopteridae (Phthiraptera, Aleyrodidae (Hemiptera and Braconidae (Hymenoptera; the replication-related elements in the A+T-rich regions of these species are inverted, confirming that reversal of strand asymmetry (GC skew was caused by inversion of replication origin; and finally, the sign of GC skew value is associated with replication orientation but not with gene direction, while that of AT skew value varies with gene direction, replication and codon positions used in analyses. These findings show that deaminations during replication and other mutations contribute more than selection on amino acid sequences to strand compositions of G and C, and that the replication process has a stronger affect on A and T content than does transcription. Our results may contribute to genome-wide studies of replication and transcription mechanisms.

Dissemination of Aleurocanthus woglumi in citrus plants, its natural enemies and new host plants in the state of Rio de Janeiro, Brazil

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Rodrigo Garcia Alvim

Full Text Available ABSTRACT: Aleurocanthus woglumi is an exotic pest, widely disseminated in Brazil, with a high preference for citrus plants, but with a polyphagous feeding habit. The contribution of the state of Rio de Janeiro in the Brazilian production of citrus fruits is small; however, there are still public policies that encourage citrus production in the state. In 2010, the appearance of this pest in Rio de Janeiro was confirmed in the municipality of Cachoeiras de Macacu. The objectives of this research were to evaluate the dissemination of A. woglumi in this state, conduct a survey of new species of host plants, identify and evaluate the population of natural enemies present at two orchards that grow 'Tahiti' limes ( Citrus latifolia infested by the pest in Cachoeiras de Macacu, RJ, Brazil. In 19 municipalities, leaves of citrus and other species of plants presenting aleyrodid nymphs were collected, and yellow sticky traps were installed to capture adults for subsequent identification. At the 'Tahiti' lime orchards, the leaf collections were done to confirm the species of Aleyrodidae , and regarding A. woglumi , the natural enemies associated with this pest were collected directly from the infested plants. The results showed that A. woglumi is wide-spread in 12 municipalities. Three new host plants for A. woglumi were identified: Artocarpus heterophyllus ( Moraceae , Pouteria caimito ( Sapotaceae and Struthanthus flexicaulis ( Loranthaceae . In Cachoeiras de Macacu, a new species of parasitoid of A. woglumi nymphs was named: Encarsia pergandiella (Hymenoptera: Aphelinidae , while the insects in the Coccinellidae (Coleoptera family have stood out as predators of this pest.

A new whitefly genus and species, Himalayaleyrodes sarcococcae Dubey (Hemiptera: Aleyrodidae) infesting Christmas box (Buxaceae) in Western Himalaya, India.

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Dubey, Anil Kumar; Singh, Sudhir

2017-05-24

Puparia, immatures and adults of a new whitefly genus and species, Himalayaleyrodes sarcococcae Dubey are described from the Western Himalaya, India. The new species was found feeding on leaves as well as on green stems of Sarcococca saligna (D. Don) Muell. Biological information, habitus, line arts, photomicrographs of holotype and Scanning Electron Microscope (SEM) images are given for this new taxon. Also, we discuss similarities and dissimilarities of puparia of the new genus with its closely related genus Bemisia Quaintance & Baker. Feeding behaviour is discussed.

Primer registro de “la mosca negra de los cítricos” Aleurocanthus woglumi (Hemiptera: Aleyrodidae en la Argentina

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Silvia N. LÓPEZ

2011-01-01

Full Text Available Aleurocanthus woglumi Ashby es una especie polífaga que ataca principalmente cultivos de Citrus spp. El objetivo de este trabajo es dar a conocer la primera detección de A. woglumi en Argentina. Los especímenes estudiados fueron recolectados en cultivos de pomelo en Tres Lagunas, departamento de Pilagá, Formosa, en febrero de 2011.

Scale insects and mealy bugs (Homoptera: Coccoidea) attacking deciduous fruit trees in the western north coast of Alexandria, Egypt.

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Mourad, A K; Moursi Khadiga, S; Mesbah, H A; Abdel-Razak Soad, I

2008-01-01

This investigation covered a survey of scale insects and mealy bugs infesting ten growing species of deciduous fruit trees in three localities in Alexandria govemorate. These localities were Merghem, Burg El-Arab, and El-Nahda about 50 Km. West of Alexandria under both rain-fed and irrigation system conditions. The common inspected fruit trees were fig, white mulberry, pomegranate, apple, pear, apricot, European plum, peach, almond, and persimmon. It was shown that a group of twenty scale insects and meaty bug species pertaining to fifteen genera belonging to six families of the super family: Coccoidea were collected and identified during the elapsing period from January to December, 2004. Among these species, Diaspidiotus perniciosus (Comstock) was recorded for the first time in Egypt. In the present study, many insect and non-insect parasitoids and predators were also found associated with these scale insects and mealy bugs on deciduous fruit trees in the three concerned localities throughout this investigation. These natural enemies were identified and recorded.

Life table analysis of the performance of aphid Sitobion avenae (Homoptera: Aphididae nymphs exposed to a static magnetic field

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He Juan

2013-01-01

Full Text Available Using the age-stage two-sex life table, this work was undertaken in order to determine the effect of static magnetic fields (SMFs at two flux densities (0.176T and 0.065T applied at increasing times of duration (0.25, 0.5, 1 and 2 h on the development, fecundity and reproduction of the aphid, Sitobion avenae. Exposed nymphs had a statistically significant shortened first instar period and adult longevity and prolonged fourth instar periods compared to controls. There were significant differences in the population parameters for two exposure combinations, 0.176T for 0.5 h and 0.065T for 1 h. The intrinsic rate of increase (r, net reproductive rate (R0 and mean generation time (T were 0.1165, 3.5 and 11.7 days, respectively, 0.176 T for 0.5 h and -0.0198, 0.7 and 11.8 days, respectively, 0.065T for 1 h. We therefore recommend using the age-stage, two-sex life table to study the effect of the static magnetic field on development and growth of the aphid, Sitobion avenae.

Phenology, natural enemies, and efficacy of horticultural oil for control of Chionaspis heterophyllae (Homoptera: Diaspididae) on Christmas tree plantations.

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Fondren, Kirsten M; McCullough, Deborah G

2005-10-01

Pine needle scale, Chionaspis pinifoliae (Fitch), and Chionaspis heterophyllae Cooley are important pests of Scots pine, Pinus sylvestris L., and other conifers in much of North America. On Christmas tree plantations, these insects are typically controlled by spraying broad-spectrum insecticides when the vulnerable immature stages are present. However, effective control of bivoltine populations can be difficult to achieve due to asynchronous hatch and development of the second generation. Our objectives were to 1) determine the phenology of the second generation of C. heterophyllae in Michigan; 2) characterize the natural enemy complex; and 3) assess the effectiveness of horticultural oil for control of C. heterophyllae on P. sylvestris Christmas tree plantations. We monitored scale populations in three counties in lower Michigan for 3 yr. Scale phenology was consistently associated with cumulative degree-days base 10 degrees C (DD(10 degrees C)). Second-generation egg hatch began at approximately 1230-1300 DD(10 degrees C), and continued for approximately 3 wk. The peak of the second instar coincided with 1500-1600 DD(10 degrees C). Common predators included the coccinellids Chilocorus stigma (Say) and Microweisia misella (LeConte). On average, 70% of the C. heterophyllae population in unsprayed fields was killed by predators in 1999. Two endoparasitic wasps, Encarsia bella Gahan and Marietta mexicana Howard (Hymenoptera: Aphelinidae), also were recovered. In 2000 and 2001, we applied a highly refined horticultural spray oil with a backpack mist blower at 1500-1600 DD(10 degrees). Scale mortality on trees treated with oil ranged from 66 to 80% and was similar to control achieved using conventional insecticides in both years.

Susceptibility to neonicotinoids and risk of resistance development in the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae).

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Wang, Yanhua; Chen, Jin; Zhu, Yu Cheng; Ma, Chongyong; Huang, Yue; Shen, Jinliang

2008-12-01

In recent years, outbreaks of the brown planthopper, Nilaparvata lugens (Stål), have occurred more frequently in China. The objective of this study was to determine the susceptibility of N. lugens to neonicotinoids and other insecticides in major rice production areas in China. Results indicated that substantial variations in the susceptibility to different insecticides existed in N. lugens. Field populations had developed variable resistance levels to neonicotinoids, with a high resistance level to imidacloprid (RR: 135.3-301.3-fold), a medium resistance level to imidaclothiz (RR: 35-41.2-fold), a low resistance level to thiamethoxam (up to 9.9-fold) and no resistance to dinotefuran, nitenpyram and thiacloprid (RR buprofezin. In addition, N. lugens had been able to develop 1424-fold resistance to imidacloprid in the laboratory after the insect was selected with imidacloprid for 26 generations. Long-term use of imidacloprid in a wide range of rice-growing areas might be associated with high levels of resistance in N. lugens. Therefore, insecticide resistance management strategies must be developed to prevent further increase in resistance.

Effect of different humidity levels on the biology of longtailed mealy bug pseudococcus longispinus (targioni and tozzetti) (homoptera: pseudococidae)

International Nuclear Information System (INIS)

Gillani, W.A.

2009-01-01

On determining the effects of different humidity levels on the biology of mealy bug Pseudococcus longispinus (Targioni and Tozzetti), it was found that the relative humidity (RH) at 35%, 55% and 75% had no effect on pre-adult development, adult longevity, life span and fecundity of P. longispinus. The survival of pre-adult stages was minimal at 35% RH. Sex ratio was male-biased at 35% RH and female-biased at 75% RH. (author)

Richness and composition of gall-inducing arthropods at Coiba National Park, Panama

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José Luis Nieves-Aldrey

2008-09-01

Full Text Available Interest in studying galls and their arthropods inducers has been growing rapidly in the last two decades. However, the Neotropical region is probably the least studied region for gall-inducing arthropods. A study of the richness and composition of gall-inducing arthropods was carried out at Coiba National Park in the Republic of Panama. Field data come from samples obtained between August 1997 and September 1999, with three (two-week long more intensive samplings. Seventeen sites, representing the main land habitats of Coiba National Park were surveyed. 4942 galls of 50 insect and 9 mite species inducing galls on 50 vascular plants from 30 botanical families were colleted. 62.7% of the galls were induced by gall midges (Diptera, Cecidomyiidae, 15.3% by mites, Eriophyidae, 8.5% by Homoptera, Psyllidae, 6.8% by Coccidae and 5.1% by Phlaeothripidae (Tysanoptera. The host plant families with the most galls were Myrtaceae with seven, Bignoniaceae with five and Euphorbiaceae, Fabaceae and Melastomataceae with four. Leaf galls accounted for about 93% of collected galls. Most leaf galls were pit/blister galls followed by covering and pouch galls. Gall richness per collecting site was between 1 and 19 species. Coiba’s gall diversity is discussed in relation to data available from other tropical sites from continental Panama and the Neotropical region. Our results support the idea that it may be premature to conclude that species richness of gall inducers declines near the equator. Rev. Biol. Trop. 56 (3: 1269-1286. Epub 2008 September 30.El interés por el estudio de las agallas y los artrópodos que las inducen ha crecido en todo el mundo en los últimos veinte años. Sin embargo, los artrópodos que inducen agallas en la región Neotropical son probablemente los menos estudiados. Un estudio de la riqueza y composición de artrópodos que inducen agallas fue desarrollado en el Parque Nacional Coiba en la Republica de Panamá. Los datos provienen de

Transgenic plants expressing the AaIT/GNA fusion protein show increased resistance and toxicity to both chewing and sucking pests.

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Liu, Shu-Min; Li, Jie; Zhu, Jin-Qi; Wang, Xiao-Wei; Wang, Cheng-Shu; Liu, Shu-Sheng; Chen, Xue-Xin; Li, Sheng

2016-04-01

The adoption of pest-resistant transgenic plants to reduce yield losses and decrease pesticide use has been successful. To achieve the goal of controlling both chewing and sucking pests in a given transgenic plant, we generated transgenic tobacco, Arabidopsis, and rice plants expressing the fusion protein, AaIT/GNA, in which an insecticidal scorpion venom neurotoxin (Androctonus australis toxin, AaIT) is fused to snowdrop lectin (Galanthus nivalis agglutinin, GNA). Compared with transgenic tobacco and Arabidopsis plants expressing AaIT or GNA, transgenic plants expressing AaIT/GNA exhibited increased resistance and toxicity to one chewing pest, the cotton bollworm, Helicoverpa armigera. Transgenic tobacco and rice plants expressing AaIT/GNA showed increased resistance and toxicity to two sucking pests, the whitefly, Bemisia tabaci, and the rice brown planthopper, Nilaparvata lugens, respectively. Moreover, in the field, transgenic rice plants expressing AaIT/GNA exhibited a significant improvement in grain yield when infested with N. lugens. This study shows that expressing the AaIT/GNA fusion protein in transgenic plants can be a useful approach for controlling pests, particularly sucking pests which are not susceptible to the toxin in Bt crops. © 2015 Institute of Zoology, Chinese Academy of Sciences.

Residue and bio-efficacy evaluation of controlled release formulations of imidacloprid against pests in soybean (Glycine max).

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Adak, Totan; Kumar, Jitendra; Dey, Debjani; Shakil, N A; Walia, S

2012-01-01

Controlled release (CR) formulations of imidacloprid (1-(6 chloro-3-pyridinyl methyl)-N- nitro imidazolidin-2- ylideneamine) were prepared using novel amphiphilic polymers synthesized from polyethylene glycol and aliphatic diacids employing encapsulation technique. The bioefficacy of the prepared CR formulations was evaluated against major pests of soybean, namely stem fly, Melanagromyza sojae Zehntmer and white fly, Bemisia tabaci Gennadius along with a commercial formulation at the experimental farm of Indian Agricultural Research Institute (IARI), New Delhi during kharif 2009 and 2010. Most of the CR formulations of imidacloprid gave significantly better control of the pests compare to its commercial formulations, however the CR formulations, Poly [poly (oxyethylene-1000)-oxy suberoyl] amphiphilic polymer based formulation performed better over others for controlling of both stem fly incidence and Yellow Mosaic Virus (YMV) infestation transmitted by white fly. Some of the developed CR formulations recorded higher yield over commercial formulation and control. Nodulation pattern of soybean was not affected due to treatment of CR and commercial formulations of imidacloprid. Also the residues of imidacloprid in seed and soil at harvest were not detectable for both CR and commercial formulations.

Seed Treatment Combined with a Spot Application of Clothianidin Granules Prolongs the Efficacy of Controlling Piercing-Sucking Insect Pests in Cotton Fields.

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Zhang, Zhengqun; Zhao, Yunhe; Wang, Yao; Li, Beixing; Lin, Jin; Zhang, Xuefeng; Mu, Wei

2017-09-13

Seed treatments can directly protect cotton from early season piercing-sucking insect Aphis gossypii Glover but hardly provide long-term protection against Apolygus lucorum (Meyer-Dür). Therefore, the efficacy of clothianidin seed treatments combined with spot applications of clothianidin granules at the bud stage of cotton was evaluated to control piercing-sucking pests during the entire cotton growing season. Clothianidin seed treatments (at the rate of 4 g ai/kg seed) combined with a clothianidin granular treatment (even at low rate of 0.9 kg ai/ha) at the bud stage can effectively suppress A. gossypii and A. lucorum infestations throughout the seedling and blooming stages after planting and can improve cotton yield. The spot application of clothianidin granules also reduced the population densities of Bemisia tabaci (Gennadius). The dynamic changes of clothianidin residues demonstrated that the control efficacy of clothianidin against A. gossypii and A. lucorum might be related to the residues of this neonicotinoid in cotton leaves. This pest management practice provided long-term protection against cotton piercing-sucking pests for the entire growing season of cotton plants and could supplement the short-term control efficiency of clothianidin used as a seed treatment.

Suscetibilidade de genótipos de feijão ao vírus-do-mosaico-dourado

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Lemos Leandro Borges

2003-01-01

Full Text Available O objetivo deste trabalho foi avaliar a suscetibilidade de diversos genótipos de feijão ao vírus-do-mosaico-dourado (VMDF, transmitido pela mosca branca (Bemisia tabaci. A semeadura foi realizada na época da seca e das águas, com e sem aplicação do inseticida granulado Aldicarb (3,0 kg ha-1 do i.a. no sulco de semeadura. O delineamento experimental utilizado foi o de blocos casualizados disposto em esquema fatorial 14x2, representado por genótipos e inseticida, respectivamente, com quatro repetições. A maior infestação de mosca-branca e incidência do vírus ocorreu na época da seca, causando prejuízos à produção do feijoeiro. Os genótipos apresentaram diferentes graus de suscetibilidade ao vírus e ao inseto vetor. Os genótipos mais tolerantes foram IAPAR 57, IAPAR 65, IAPAR 72, Ônix, Aporé e 606 (5(214-17. A aplicação do inseticida sistêmico controla o vetor em ambas as épocas de cultivo, proporcionando aumentos da produtividade.

Synthesis and biological activity of a new class of insecticides: the N-(5-aryl-1,3,4-thiadiazol-2-yl)amides.

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Eckelbarger, Joseph D; Parker, Marshall H; Yap, Maurice Ch; Buysse, Ann M; Babcock, Jonathan M; Hunter, Ricky; Adelfinskaya, Yelena; Samaritoni, Jack G; Garizi, Negar; Trullinger, Tony K

2017-04-01

Optimization studies on a high-throughput screening (HTS) hit led to the discovery of a series of N-(6-arylpyridazin-3-yl)amides with insecticidal activity. It was hypothesized that the isosteric replacement of the pyridazine ring with a 1,3,4-thiadiazole ring could lead to more potent biological activity and/or a broader sap-feeding pest spectrum. The resulting N-(5-aryl-1,3,4-thiadiazol-2-yl)amides were explored as a new class of insecticides. Several methods for 2-amino-1,3,4-thiadiazole synthesis were used for the preparation of key synthetic intermediates. Subsequent coupling to variously substituted carboxylic acid building blocks furnished the final targets, which were tested for insecticidal activity against susceptible strains of Aphis gossypii (Glover) (cotton aphid), Myzus persicae (Sulzer) (green peach aphid) and Bemisia tabaci (Gennadius) (sweetpotato whitefly). Structure-activity relationship (SAR) studies on both the amide tail and the aryl A-ring of novel N-(5-aryl-1,3,4-thiadiazol-2-yl)amides led to a new class of insecticidal molecules active against sap-feeding insect pests. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Luta biológica clássica com Hyperaspis pantherina Fürsch (Coleoptera: Coccinellidae no combate à Orthezia insignis Browne (Homoptera: Ortheziidae em jacarandá Biological control with Hyperaspis pantherina Fürsch (Coleoptera: Coccinellidae to control Orthezia insignis Browne (Homoptera: Ortheziidae on blue jacaranda

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Ana Paula Félix

2008-12-01

Full Text Available Os jacarandás e várias plantas ornamentais que ornamentam passeios e áreas ajardinadas da cidade do Funchal encontram-se infestados pela cochonilha Orthezia insignis Browne. Para combater esta praga foi importada do Quénia, uma joaninha, Hyperaspis pantherina Fürsch. Este predador é específico de O. insignis e tem sido utilizado, com sucesso em programas de luta biológica, em vários países de África, no Peru, Hawai e na Ilha de Santa Helena. Na Ilha da Madeira, desde Julho de 2002, H. pantherina está a ser criado em laboratório e largado em jacarandás infestados com o objectivo de combater a cochonilha-dojacarandá através da luta biológica clássica. Referem-se as largadas de H. pantherina e o sistema de monitorização adoptado para verificar a aclimatação do predador.The Jacaranda trees and other ornamental plants used in sidewalks and gardenlike areas of sidewalks and other gardened areas of the downton Capital city of Madeira Island (Funchal, are infested by the Jacaranda or Lantana Bug, Orthezia insignis Browne. A ladybird, Hyperaspis pantherina Fürsch, was imported from Kenya to control this pest. This ladybird is a specific predator of O. insignis and it has been used, successfully in biological control programs, in several countries of Africa, in Peru, Hawaii and in Santa Helena Island. In Madeira Island, H. pantherina is being reared in laboratory and released into infested jacarandas since July 2002, in a classical biological control way. The releasing of H. pantherina is described in detail as well as the adopted monitoring system to verify its acclimation.

Temporal and spatial changes in the diet of Hyla pulchella (Anura, Hylidae in southern Uruguay

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Inés da Rosa

2004-12-01

Full Text Available In this article we report the diet of a population of the hylid frogHyla pulchella from southeastern Uruguay. We collected the specimens in ponds, where we identified microenvironments defined by the invertebrate assemblage, during one year divided into two seasons (warm and cold. We taxonomically determined 10365 invertebrates belonging to 21 categories in the digestive tracts of frogs. Weestimated the diversity of the diet and alimentary preference according to microenvironments and seasons. We estimated the expected richness of both diet and prey availability using a null model based on the hypergeometric distribution. We performed Discriminant Analyses and Kruskal-Wallis tests to detect changes in prey availability among microenvironments and between seasons. The overall diet in terms of frequencies was composed primarily of arthropods (mainly Araneae, Diptera, Hymenoptera, and Coleoptera and in terms of volume, by larvae. The most relevantitems to study the microenvironmental and seasonal variation in the available preys were Araneae, Collembola, Homoptera, Hymenoptera, Diptera, Dictioptera, Lepidoptera, Coleoptera, and larvae. Based on the null model curves and preference indexes we inferred positive selection by larvae, Isopoda, Dictioptera, Lepidoptera, and Diptera, and negative selection by Collembola and Hymenoptera. The diversityof diet and the null model curves indicated that the diet changes among microenvironments and seasons. This frog may be considered as a middle generalist predator, with some selective behavior and a combined search strategy (active and sit-and-wait. We conclude that the knowledge about the availability of preys is a relevant tool for trophic studies.

Seleksi Resistansi Wereng Batang Padi Coklat terhadap Insektisida Fipronil

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Melhanah Melhanah

2002-12-01

Full Text Available The rice brown planthoper, Nilaparvata lugens Stal (Homoptera: Delphacidae, is one of  key pests on rice. The use of insecticides unwisely has caused N. lugens to develop resistance. The objective of this research was to determine the potency of N. lugens to develop resistance through laboratory, selections to fipronil, a relatively new insecticide.  A population of N. lugens was collected from rice field in Muntilan, Central Java during the outbreak in 2001. Selections were carried out every generation for four generations against third instars. Selection was started by dipping Cisadane rice seedlings in a solution of fipronil (50 ppm. The concentration was increased every generation, and the concentration used for the last selection (the fourth generation was 250 ppm. To determine the rate of resistance development, biassays were carried out to estimate LC50 of fipronil against selected and non-selected populations of N. lugens, and their LC50 values were compared to that of the laboratory population. The laboratory population has been in the laboratory for 15 years without any insecticides exposure. The founding population was as susceptible as the laboratory population to fipronil because their LC50 values were similar. Even though the concentration for selections was increased from generation to generation, the survival rate of N. lugens increased steadily. After four generations of selection, the resistance of selected population was 27.3 times than the non-selected population. These findings indicate that N. lugens population has the potency to develop resistance to fipronil in a continuous selection pressure is applied.

Introduced and invasive insect species in the Czech Republic and their economic and ecological impact (Insecta

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Hana Šefrová

2005-01-01

Full Text Available A total of 383 alien insect species were registered in the Czech Republic, which represents 1.4% of local fauna. The most numerous taxonomic groups are Homoptera (116 species, 30.3%, Coleoptera (110; 28.7% and Lepidoptera (37; 9.7%. The occurrence of 200 species (52.2% are limited to closed heated spaces, casual aliens (28; 7.3% infiltrate the outdoor environment for a short term only, 36 (9.4% naturalized non-invasive species do not spread from the location of introduction, 50 (13.1% species are post-invasive and 69 (18.0% invasive. From the species registered, 61 (15.9% are stored product pests (especially Coleoptera 36 species, Psocoptera 11, and Lepidoptera 9, 50 (13.1% are plant pests indoors (especially Coccinea 33 species, Aphidinea 7, and Thysanoptera 6, 25 (i.e. 6.5% of aliens are pests in agriculture, forestry, and in ornamental cultures, 15 species (3.9% are important animal parasites, and 5 species (1.3% can affect biodiversity. Of the remaining 227 species (59.3%, no economic or ecological effects were found. The origin of most of the species living eusynanthropically is in the tropics and subtropics; of the 155 naturalized (non-invasive, post-invasive, and invasive species, 42 (27.1% originate from the Mediterranean, 36 (23.2% from North America, 28 (18.1% from Central to Southwest Asia, 14 (9.0% from East Asia, 13 (8.4% from South and Southeast Asia, with the remaining 22 species (14.2% coming from other areas.

Composition of arthropod species assemblages in Bt-expressing and near isogenic eggplants in experimental fields.

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Arpaia, Salvatore; Di Leo, Grazia M; Fiore, Maria C; Schmidt, Jörg E U; Scardi, Michele

2007-02-01

The environmental impact of genetically modified (GM) plants in experimental fields has been examined in several ways, in particular with respect to the dynamics of specific nontarget organisms. The approach of sampling for biodiversity in agroecosystems to compare complex patterns could also be useful in studying potential disruptions caused by GM crops. In this study, we set up replicated field plots of Bt-expressing eggplants and near isogenic untransformed eggplants as a control. We monitored the presence and abundance of herbivore and predator arthropods in weekly visual samplings of the plant canopy for three growing seasons (2001-2003). Insect species were pooled in organismal taxonomic units (OTUs); three multivariate methods were used to compare species assemblage as an estimate of insect biodiversity. This multistep statistical approach proved to be efficient in recognizing association patterns, as evidenced by the data for the target species Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae) clearly showing a significant association with the control plots. All the analyses indicate a comparable species assemblage between transgenic and near isogenic eggplant areas. Our results suggest that some taxa may warrant more specific study. For example, Alticinae beetles (Coleoptera: Chrysomelidae) were alternatively more abundant in either of the two treatments, and their overall abundance was significantly higher on transgenic eggplants. In light of these results and because of their taxonomic proximity to the target species, these herbivores may represent an important nontarget group to be further studied. Moreover, some sap feeders (e.g., Homoptera: Cicadellidae) were more abundant on Bt-expressing plants in some samples in all 3 yr.

Aphid wing induction and ecological costs of alarm pheromone emission under field conditions.

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Eduardo Hatano

2010-06-01

Full Text Available The pea aphid, Acyrthosiphon pisum Harris, (Homoptera: Aphididae releases the volatile sesquiterpene (E-beta-farnesene (EBF when attacked by a predator, triggering escape responses in the aphid colony. Recently, it was shown that this alarm pheromone also mediates the production of the winged dispersal morph under laboratory conditions. The present work tested the wing-inducing effect of EBF under field conditions. Aphid colonies were exposed to two treatments (control and EBF and tested in two different environmental conditions (field and laboratory. As in previous experiments aphids produced higher proportion of winged morphs among their offspring when exposed to EBF in the laboratory but even under field conditions the proportion of winged offspring was higher after EBF application (6.84+/-0.98% compared to the hexane control (1.54+/-0.25%. In the field, the proportion of adult aphids found on the plant at the end of the experiment was lower in the EBF treatment (58.1+/-5.5% than in the control (66.9+/-4.6%, in contrast to the climate chamber test where the numbers of adult aphids found on the plant at the end of the experiment were, in both treatments, similar to the numbers put on the plant initially. Our results show that the role of EBF in aphid wing induction is also apparent under field conditions and they may indicate a potential cost of EBF emission. They also emphasize the importance of investigating the ecological role of induced defences under field conditions.

Dietary analysis of Homonota darwini (Squamata: Gekkoni-dae in Northern Patagonia

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Marcelo E. KUN, Carla PIANTONI, John D. KRENZ, Nora R. IBARGÜENGOYTÍA

2010-08-01

Full Text Available Our study investigated the diet of the southernmost gecko in the world, Homonota darwini. Fifty-three specimens were captured during spring and summer in four locations in Patagonia, Argentina. The stomach contents of the specimens were identified, and we found that prey consisted of six main groups: Coleoptera, Hymenoptera, Homoptera and Araneae, and the adults and larvae of moth Lepidoptera. Lepidoptera was the major dietary component. The presence of ants and moths as common prey suggests an ambush feeding strategy. In spring, females consumed more ants than males although no other dietary differences between males and females were evident. We found nine geckos with empty stomachs and six parasitized by nematodes. Presence of empty stomachs corroborates previous observations of other nocturnal geckos and non-gecko lizards. Reduced foraging success of nocturnal lizards could be due to difficulty in prey detection due to dim light, reduced or erratic activity of insect prey at night, or shorter activity times of geckos relative to diurnal success. Sex and season were not associated with the incidence of empty stomachs. Principal component analysis showed that four food alternatives correlated with season. The constraint of nocturnality, coupled with low night-time temperatures restricting feeding to only a few hours after sunset, appear to have caused a generality of diet which may limit energy acquisition. We conclude that H. darwini is an arthropod generalist and likely an ambush forager, as are many other nocturnal gekkonids [Current Zoology 56 (4: 406–410, 2010].

Evaluation of airborne methyl salicylate for improved conservation biological control of two-spotted spider mite and hop aphid in Oregon hop yards.

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Woods, J L; James, D G; Lee, J C; Gent, D H

2011-12-01

The use of synthetic herbivore-induced plant volatiles (HIPV) to attract natural enemies has received interest as a tool to enhance conservation biological control (CBC). Methyl salicylate (MeSA) is a HIPV that is attractive to several key predators of two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), and hop aphid, Phorodon humuli (Schrank) (Homoptera: Aphididae). A 2-year study was conducted to evaluate the recommended commercial use of MeSA in hop yards in Oregon. Slow-release MeSA dispensers were stapled to supporting poles in 0.5 ha plots and these plots were compared to a paired non-treated plot on each of three farms in 2008 and 2009. Across both years, there was a trend for reduced (range 40-91%) mean seasonal numbers of T. urticae in five of the six MeSA-baited plots. Stethorus spp., key spider mite predators, tended to be more numerous in MeSA-baited plots compared to control plots on a given farm. Mean seasonal densities of hop aphid and other natural enemies (e.g., Orius spp. and Anystis spp.) were similar between MeSA-treated and control plots. Variability among farms in suppression of two-spotted spider mites and attraction of Stethorus spp. suggests that the use of MeSA to enhance CBC of spider mites in commercial hop yards may be influenced by site-specific factors related to the agroecology of individual farms or seasonal effects that require further investigation. The current study also suggests that CBC of hop aphid with MeSA in this environment may be unsatisfactory.

Resistência de soja a insetos: VIII. IAC 78-2318, linhagem com resistência múltipla Resistance of soybean to insects: VIII. IAC 78-2318 line with multiple insect resistance

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André Luiz Lourenção

1987-01-01

Full Text Available Estudou-se, em comparação com outros genótipos de soja, o comportamento da linhagem IAC 78-2318, em relação à oviposição e colonização da mosca-branca Bemisia tabaci (Genn. e à área foliar consumida por besouros crisomelídeos e lagartas. Em Campinas, SP, em 1981, em casa de vegetação, submeteram-se os cultivares Santa Rosa, Paraná, BR-1, Bossier, IAC 8 e IAC 12 e as linhagens IAC 73-228, IAC 78-2318, D72-9601-1, PI 171451, PI 229358 e PI 274454 à infestação artificial de adultos da mosca-branca. IAC 78-2318, embora apresentando alto número de ovos, teve colonização baixa, próxima aos materiais mais resistentes (PI 171451 e PI 229358. Em Santo Antonio de Posse, SP, em 1985, em campo, IAC 78-2318, quando comparado com IAC 80-596-2, 'Santa Rosa', 'IAC 8' e 'IAC 11', mostrou a menor perda de área foliar devida à alimentação de coleópteros crisomelídeos, principalmente Cerotoma arcuata (Oliv. e Diphaulaca viridipennis Clark, e de lagartas, com predominância de Anticarsia gemmatalis (Hubn.. Como já havia sido registrado anteriormente baixo dano de Epinotia aporema (Wals. e de percevejos pentatomideos em IAC 78-2318, com as observações presentes essa linhagem fica caracterizada como portadora de resistência múltipla a insetos.The performance of the soybean line IAC 78-2318 in relation to oviposition and colonization by the whitefly Bemisia tabaci (Genn. and to defoliation by caterpillars and chrysomelidae was studied in comparison to other varieties. At Campinas, State of São Paulo - Brazil, in greenhouse, the cultivars Santa Rosa, Paraná, BR-1, Bossier, IAC 8 and IAC 12, and the lines IAC 73-228, IAC 78-2318, D72-9601-1, PI 171451, PI 229358 e PI 274454 were submitted to artificial infestation of whitefly adults from tomato plants highly infested. Despite the high number of eggs in the IAC 78-2318 folioles, this line had a low colonization, comparable to the more resistants lines (PI 171451 and PI 229358. At Santo

Evaluación de extractos cetónicos de paraíso, eucalipto y ricino sobre Myzus persicae (Homoptera: Aphididae)

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Carrizo, Paola; Pelicano, Alicia; Caffarini, Patricia

2004-01-01

En el cultivo de pimiento, Myzus persicae es una plaga cuyo manejo se basa en el uso de agroquímicos de síntesis. Una alternativa de menor impacto ambiental para su control es la aplicación de extractos naturales. El objetivo del trabajo fue evaluar el efecto de extractos provenientes de Melia azedarach, Eucalyptus globulus y Ricinus communis sobre este pulgón. Se escogió la técnica del film residual en papel de filtro, manteniendo los individuos sobre hojas de pimiento ornamental. Se uti...

The impact of some physiomorphic characters of sugarcane genotypes on their resistance against sugarcane pyrilla, pyrilla perpusilla wlk. (lophopidae: homoptera)

International Nuclear Information System (INIS)

Rasul, A.; Hassan, M.; Suhail, A.; Sahi, S.T.

2010-01-01

Field trials were conducted in the Research Area, Directorate of Sugarcane, Ayub Agricultural Research Institute, Faisalabad to study he physio-morphic characters of sugarcane resistance to the sucking pest Pyrilla perpusilla. Twenty genotypes of sugarcane were tested for their resistance susceptibility against P. perpusilla, as a preliminary screening experiment, during 2006. Based on the population-density count, 3 genotypes, viz., HSF- 240, CPF-243 and S-2002-US-114 showing resistance responses, 3 genotypes viz. CPHS-35, S-2003-US-394 and S-2003-US-623 showing susceptible trends and 3 genotypes viz. S-2003-US-809, S-2002-US-140 and S- 2002-US-104 exerting intermediate trends against the pest under test were selected for the final screening trials during 2007.The genotype S-2003-US-623, was found to be comparatively susceptible; whereas, HSF-240, showed resistance responses. The leaf-width and cane length showed a positive and significant correlation whereas the leaf-spine density had a significant negative effect with pest-population. The Leaf-length and Cane-Diameter did not show a significant correlation with the pest population. (author)

Reproducción de cochinilla silvestre Dactylopius opuntiae (Homóptera: Dactylopiidae Reproduction of wild cochineal Dactylopius opuntiae (Homoptera: Dactylopiidae

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Arnoldo Flores-Hernández

2006-06-01

Full Text Available Por sus características, la cochinilla silvestre ofrece perspectivas de aprovechamiento como fuente de carmín y para el mejoramiento genético de la grana fina. Por lo anterior, se estableció una multiplicación y crianza de cochinilla silvestre, proveniente de la zona árida del norte de México para caracterizarla, utilizando como hospedero a Opuntia megacantha Salm Dyck. Los resultados indican que la especie silvestre pertenece al género-especie Dactylopius opuntia. Se determinó la presencia de partenogénesis en hembras. La duración de los estadios biológicos depende del sexo del insecto; el adulto hembra permaneció durante 38.4 días y 4.2 días para machos, los primeros estadios ninfales fueron similares en duración (18.1-19.8 días. El ciclo biológico de las hembras fue de 77 días mientras que el de los machos fue de 43 días. Para las hembras se estimó un periodo de preoviposición de 18.8 días, manteniéndose en oviposición durante 21 días con un promedio de 131 insectos por hembra. La proporción sexual hembras: machos fue 1:1. El tipo de reproducción fue predominantemente sexual, aunque hubo hembras partenogénicas. Este es el primer reporte de Dactylopius opuntiae como cochinilla silvestre asociada a la zona árida del noreste de México, específicamente en el Bolsón de Mapimí, Durango, México.Wild cochineal has characteristics that offer advantage as a source of carmine and for fine cochineal improvement. To characterize wild cochineal, we initiated a breeding effort raising wild cochineal from the arid zone of the north oh Mexico, using as a host organism Opuntia megacantha Salm dick. The results indicate that the wild specie is Dactylopius opuntiae. The presence of parthenogenesis in females was determined. The duration of ontogenetic stages depends on the sex of the insect. The adult female lasted 38.4 days and 4.2 days for males, the first stage nymphs were similar in duration (18-19.8 days. The complete biological cycle of the females was 77 days, and in the males 43 days. A period of preoviposition of 18.8 days for the females was found, laying eggs during 21 days with an average of 131 insects per female. The sex ratio female: male was 1:1. The reproduction generally was sexual although there were parthenogenetic females. This is the first report of Dactylopius opuntiae as a source of wild cochineal in the arid zone of North, Central and Norwest of Mexico specifically in the Bolson of Mapimí, Durango, Mexico.

The environmental plasticity of diverse body color caused by extremely long photoperiods and high temperature in Saccharosydne procerus (Homoptera: Delphacidae

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Haichen Yin

2016-09-01

Full Text Available Melanization reflects not only body color variation but also environmental plasticity. It is a strategy that helps insects adapt to environmental change. Different color morphs may have distinct life history traits, e.g., development time, growth rate, and body weight. The green slender planthopper Saccharosydne procerus (Matsumura is the main pest of water bamboo (Zizania latifolia. This insect has two color morphs. The present study explored the influence of photoperiod and its interaction with temperature in nymph stage on adult melanism. Additionally, the longevity, fecundity, mating rate, and hatching rate of S. procerus were examined to determine whether the fitness of the insect was influenced by melanism under different temperature and photoperiod. The results showed that a greater number of melanic morphs occurred if the photoperiod was extremely long. A two-factor ANOVA showed that temperature and photoperiod both have a significant influence on melanism. The percentages of variation explained by these factors were 45.53% and 48.71%, respectively. Moreover, melanic morphs had greater advantages than non-melanic morphs under an environmental regime of high temperatures and a long photoperiod, whereas non-melanic morphs were better adapted to cold temperatures and a short photoperiod. These results cannot be explained by the thermal melanism hypothesis. Thus, it may be unavailable to seek to explain melanism in terms of only one hypothesis.

Comparison of AC electronic monitoring and field data for estimating tolerance to Empoasca kraemeri (Homoptera: Cicadellidae) in common bean genotypes.

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Serrano, M S; Backus, E A; Cardona, C

2000-12-01

Two methods for estimating the tolerance of common bean genotypes to Empoasca kraemeri Ross & Moore were compared, using a yield trial carried out at Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia, versus stylet penetration tactics measured by AC electronic feeding monitors. A stylet penetration index was devised based on principal component scores of three penetration tactics identified (pulsing laceration, cell rupturing, and lancing sap ingestion), combined with knowledge of the hopperburn symptoms caused by each tactic. Tolerant genotypes, as classified by the CIAT yield index, showed significantly more unprotected yield and lower hopperburn scores than the susceptible control. They also induced performance of less pulsing laceration (the tactic considered most damaging to the plant), and more of the other two, mitigating tactics, especially cell rupturing. When index values were calculated for each genotype, stylet penetration index values matched those of the yield index for three out of five genotypes: two EMP-coded tolerant lines ('EMP 385' and 'EMP 392') and the susceptible control 'BAT 41'. Thus, for these three genotypes, all subsequent hoppereburn symptoms are predictable by the type of feeding behavior performed on them. 'Porrillo Sintético' and 'EMP 84', considered borderline genotypes by the yield index, were overestimated and underestimated respectively, by the stylet penetration index. We postulate that, for these two genotypes, plant physiological responses to feeding (either compensatory or heightened sensitivity, respectively) synergize with type of feeding performed to generate the overall hopperburn condition. This multivariate analysis of electronic monitoring data was successfully used to devise an index of resistance. The implications of using the stylet penetration index and the advantages of using electronic monitoring in a bean-breeding program are discussed.

Inheritance mode and realized heritability of resistance to imidacloprid in the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae).

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Wang, Yan Hua; Liu, Xu Gan; Zhu, Yu Cheng; Wu, Sheng Gan; Li, Shu Yong; Chen, Wen Ming; Shen, Jin Liang

2009-06-01

The brown planthopper, Nilaparvata lugens (Stål), is a serious pest that causes enormous losses to the rice crop in Asia. The genetic basis of imidacloprid resistance was investigated in N. lugens. The resistant strain, selected for imidacloprid resistance from a field population of N. lugens collected from Nanjing, Jiangsu Province, China, showed a 964-fold resistance compared with the laboratory strain. Progenies of reciprocal crosses (F(1) and F(1)') showed similar dose-mortality responses (LC(50)) to imidacloprid, and also exhibited a similar degree of dominance (D), 0.58 for F(1) and 0.63 for F(1)'. Chi-square analyses of self-bred and backcross progenies (F(2), F(2)' and BC respectively) rejected the hypothesis for a single gene control of the resistance. The estimated realized heritability (h(2)) of imidacloprid resistance was 0.1141 in the resistant strain of N. lugens. The results showed that imidacloprid resistance in N. lugens was autosomal and was expressed as an incompletely dominant trait, probably controlled by multiple genes.

Differential profiles of direct and indirect modification of vector feeding behaviour by a plant virus.

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He, Wen-Bo; Li, Jie; Liu, Shu-Sheng

2015-01-08

Plant viruses interact with their insect vectors directly and indirectly via host plants, and this tripartite interaction may produce fitness benefits to both the vectors and the viruses. Our previous studies show that the Middle East-Asia Minor 1 (MEAM1) species of the whitefly Bemisia tabaci complex improved its performance on tobacco plants infected by the Tomato yellow leaf curl China virus (TYLCCNV), which it transmits, although virus infection of the whitefly per se reduced its performance. Here, we use electrical penetration graph recording to investigate the direct and indirect effects of TYLCCNV on the feeding behaviour of MEAM1. When feeding on either cotton, a non-host of TYLCCNV, or uninfected tobacco, a host of TYLCCNV, virus-infection of the whiteflies impeded their feeding. Interestingly, when viruliferous whiteflies fed on virus-infected tobacco, their feeding activities were no longer negatively affected; instead, the virus promoted whitefly behaviour related to rapid and effective sap ingestion. Our findings show differential profiles of direct and indirect modification of vector feeding behaviour by a plant virus, and help to unravel the behavioural mechanisms underlying a mutualistic relationship between an insect vector and a plant virus that also has features reminiscent of an insect pathogen.

DNA Barcode Analysis of Thrips (Thysanoptera) Diversity in Pakistan Reveals Cryptic Species Complexes.

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Iftikhar, Romana; Ashfaq, Muhammad; Rasool, Akhtar; Hebert, Paul D N

2016-01-01

Although thrips are globally important crop pests and vectors of viral disease, species identifications are difficult because of their small size and inconspicuous morphological differences. Sequence variation in the mitochondrial COI-5' (DNA barcode) region has proven effective for the identification of species in many groups of insect pests. We analyzed barcode sequence variation among 471 thrips from various plant hosts in north-central Pakistan. The Barcode Index Number (BIN) system assigned these sequences to 55 BINs, while the Automatic Barcode Gap Discovery detected 56 partitions, a count that coincided with the number of monophyletic lineages recognized by Neighbor-Joining analysis and Bayesian inference. Congeneric species showed an average of 19% sequence divergence (range = 5.6% - 27%) at COI, while intraspecific distances averaged 0.6% (range = 0.0% - 7.6%). BIN analysis suggested that all intraspecific divergence >3.0% actually involved a species complex. In fact, sequences for three major pest species (Haplothrips reuteri, Thrips palmi, Thrips tabaci), and one predatory thrips (Aeolothrips intermedius) showed deep intraspecific divergences, providing evidence that each is a cryptic species complex. The study compiles the first barcode reference library for the thrips of Pakistan, and examines global haplotype diversity in four important pest thrips.

Transient Expression and Cellular Localization of Recombinant Proteins in Cultured Insect Cells.

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Fabrick, Jeffrey A; Hull, J Joe

2017-04-20

Heterologous protein expression systems are used for the production of recombinant proteins, the interpretation of cellular trafficking/localization, and the determination of the biochemical function of proteins at the sub-organismal level. Although baculovirus expression systems are increasingly used for protein production in numerous biotechnological, pharmaceutical, and industrial applications, nonlytic systems that do not involve viral infection have clear benefits but are often overlooked and underutilized. Here, we describe a method for generating nonlytic expression vectors and transient recombinant protein expression. This protocol allows for the efficient cellular localization of recombinant proteins and can be used to rapidly discern protein trafficking within the cell. We show the expression of four recombinant proteins in a commercially available insect cell line, including two aquaporin proteins from the insect Bemisia tabaci, as well as subcellular marker proteins specific for the cell plasma membrane and for intracellular lysosomes. All recombinant proteins were produced as chimeras with fluorescent protein markers at their carboxyl termini, which allows for the direct detection of the recombinant proteins. The double transfection of cells with plasmids harboring constructs for the genes of interest and a known subcellular marker allows for live cell imaging and improved validation of cellular protein localization.

The Facultative Symbiont Rickettsia Protects an Invasive Whitefly against Entomopathogenic Pseudomonas syringae Strains.

Science.gov (United States)

Hendry, Tory A; Hunter, Martha S; Baltrus, David A

2014-12-01

Facultative endosymbionts can benefit insect hosts in a variety of ways, including context-dependent roles, such as providing defense against pathogens. The role of some symbionts in defense may be overlooked, however, when pathogen infection is transient, sporadic, or asymptomatic. The facultative endosymbiont Rickettsia increases the fitness of the sweet potato whitefly (Bemisia tabaci) in some populations through mechanisms that are not yet understood. In this study, we investigated the role of Rickettsia in mediating the interaction between the sweet potato whitefly and Pseudomonas syringae, a common environmental bacterium, some strains of which are pathogenic to aphids. Our results show that P. syringae multiplies within whiteflies, leading to host death, and that whiteflies infected with Rickettsia show a decreased rate of death due to P. syringae. Experiments using plants coated with P. syringae confirmed that whiteflies can acquire the bacteria at a low rate while feeding, leading to increased mortality, particularly when the whiteflies are not infected with Rickettsia. These results suggest that P. syringae may affect whitefly populations in nature and that Rickettsia can ameliorate this effect. This study highlights the possible importance of interactions among opportunistic environmental pathogens and endosymbionts of insects. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Isonitrosoacetophenone drives transcriptional reprogramming in Nicotiana tabacum cells in support of innate immunity and defense.

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Arnaud T Djami-Tchatchou

Full Text Available Plants respond to various stress stimuli by activating broad-spectrum defense responses both locally as well as systemically. As such, identification of expressed genes represents an important step towards understanding inducible defense responses and assists in designing appropriate intervention strategies for disease management. Genes differentially expressed in tobacco cell suspensions following elicitation with isonitrosoacetophenone (INAP were identified using mRNA differential display and pyro-sequencing. Sequencing data produced 14579 reads, which resulted in 198 contigs and 1758 singletons. Following BLAST analyses, several inducible plant defense genes of interest were identified and classified into functional categories including signal transduction, transcription activation, transcription and protein synthesis, protein degradation and ubiquitination, stress-responsive, defense-related, metabolism and energy, regulation, transportation, cytoskeleton and cell wall-related. Quantitative PCR was used to investigate the expression of 17 selected target genes within these categories. Results indicate that INAP has a sensitising or priming effect through activation of salicylic acid-, jasmonic acid- and ethylene pathways that result in an altered transcriptome, with the expression of genes involved in perception of pathogens and associated cellular re-programming in support of defense. Furthermore, infection assays with the pathogen Pseudomonas syringae pv. tabaci confirmed the establishment of a functional anti-microbial environment in planta.

Horizontal transmission of the insect symbiont Rickettsia is plant-mediated

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Caspi-Fluger, Ayelet; Inbar, Moshe; Mozes-Daube, Netta; Katzir, Nurit; Portnoy, Vitaly; Belausov, Eduard; Hunter, Martha S.; Zchori-Fein, Einat

2012-01-01

Bacteria in the genus Rickettsia, best known as vertebrate pathogens vectored by blood-feeding arthropods, can also be found in phytophagous insects. The presence of closely related bacterial symbionts in evolutionarily distant arthropod hosts presupposes a means of horizontal transmission, but no mechanism for this transmission has been described. Using a combination of experiments with live insects, molecular analyses and microscopy, we found that Rickettsia were transferred from an insect host (the whitefly Bemisia tabaci) to a plant, moved inside the phloem, and could be acquired by other whiteflies. In one experiment, Rickettsia was transferred from the whitefly host to leaves of cotton, basil and black nightshade, where the bacteria were restricted to the phloem cells of the plant. In another experiment, Rickettsia-free adult whiteflies, physically segregated but sharing a cotton leaf with Rickettsia-plus individuals, acquired the Rickettsia at a high rate. Plants can serve as a reservoir for horizontal transmission of Rickettsia, a mechanism which may explain the occurrence of phylogenetically similar symbionts among unrelated phytophagous insect species. This plant-mediated transmission route may also exist in other insect–symbiont systems and, since symbionts may play a critical role in the ecology and evolution of their hosts, serve as an immediate and powerful tool for accelerated evolution. PMID:22113034

A massive incorporation of microbial genes into the genome of Tetranychus urticae, a polyphagous arthropod herbivore.

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Wybouw, N; Van Leeuwen, T; Dermauw, W

2018-06-01

A number of horizontal gene transfers (HGTs) have been identified in the spider mite Tetranychus urticae, a chelicerate herbivore. However, the genome of this mite species has at present not been thoroughly mined for the presence of HGT genes. Here, we performed a systematic screen for HGT genes in the T. urticae genome using the h-index metric. Our results not only validated previously identified HGT genes but also uncovered 25 novel HGT genes. In addition to HGT genes with a predicted biochemical function in carbohydrate, lipid and folate metabolism, we also identified the horizontal transfer of a ketopantoate hydroxymethyltransferase and a pantoate β-alanine ligase gene. In plants and bacteria, both genes are essential for vitamin B5 biosynthesis and their presence in the mite genome strongly suggests that spider mites, similar to Bemisia tabaci and nematodes, can synthesize their own vitamin B5. We further show that HGT genes were physically embedded within the mite genome and were expressed in different life stages. By screening chelicerate genomes and transcriptomes, we were able to estimate the evolutionary histories of these HGTs during chelicerate evolution. Our study suggests that HGT has made a significant and underestimated impact on the metabolic repertoire of plant-feeding spider mites. © 2018 The Royal Entomological Society.

Natal Host Plants Can Alter Herbivore Competition.

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Pan, Huipeng; Preisser, Evan L; Su, Qi; Jiao, Xiaoguo; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Zhang, Youjun

2016-01-01

Interspecific competition between herbivores is widely recognized as an important determinant of community structure. Although researchers have identified a number of factors capable of altering competitive interactions, few studies have addressed the influence of neighboring plant species. If adaptation to/ epigenetic effects of an herbivore's natal host plant alter its performance on other host plants, then interspecific herbivore interactions may play out differently in heterogeneous and homogenous plant communities. We tested wether the natal host plant of a whitefly population affected interactions between the Middle-east Asia Minor 1 (MEAM1) and Mediterranean (MED) cryptic species of the whitefly Bemisia tabaci by rearing the offspring of a cabbage-derived MEAM1 population and a poinsettia-derived MED population together on three different host plants: cotton, poinsettia, and cabbage. We found that MED dominated on poinsettia and that MEAM1 dominated on cabbage, results consistent with previous research. MED also dominated when reared with MEAM1 on cotton, however, a result at odds with multiple otherwise-similar studies that reared both species on the same natal plant. Our work provides evidence that natal plants affect competitive interactions on another plant species, and highlights the potential importance of neighboring plant species on herbivore community composition in agricultral systems.

Description of a new species, Setaleyrodes machili Dubey, sp. nov. (Hemiptera: Aleyrodidae) infesting Machilus odoratissima Nees (Lauraceae) in Western Himalaya, India.

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Dubey, Anil Kumar

2017-12-10

A new species of whitefly, Setaleyrodes machili Dubey sp. nov. found infesting Machilus odoratissima Nees (Lauraceae) is described from Kufri in Himachal Pradesh and Dhanaulti and Nainital in Uttarakhand, India. The diagnostic characteristics of puparia and habitus, are illustrated with line drawings and scanning electron microphotographs. Sexual dimorphism and variation in pigmentation during the transformation of instars are noted. An identification key to puparia of Setaleyrodes species so far described is presented.

A review of the genus Tuberaleyrodes Takahashi (Hemiptera: Aleyrodidae) with description of five new species from Brunei, Hong Kong and Malaysia.

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Dubey, Anil Kumar; Martin, Jon H

2018-03-28

The whitefly genus Tuberaleyrodes Takahashi is reviewed using types and determined specimens. The generic diagnosis is redefined together with description of five new species: T. bruneiensis Dubey Martin sp. nov. from Brunei, T. crypta Dubey Martin sp. nov. from Hong Kong, and T. ordo Dubey Martin sp. nov., T. aequalis Dubey Martin sp. nov. and T. variabilis Dubey Martin sp. nov. from Malaysia. New species descriptions are accompanied with camera lucida drawings and microphotographs of holotype and paratypes. Tuberaleyrodes actinodaphnis Takahashi is elevated from its status as a variety of T. machili Takahashi to species level. Lectotypes are selected for T. actinodaphnis Takahashi Stat. nov. and T. bobuae Takahashi. Tuberaleyrodes actinodaphnis Takahashi is a new record to Taiwan. A new combination, Tuberaleyrodes glutae (Corbett) Comb. nov. is proposed for Dialeurodes glutae Corbett. Two species, T. glutae (Corbett) and Tuberaleyrodes spiniferosa (Corbett) are re-described, and placement of T. spiniferosa in the genus Tuberaleyrodes is confirmed. The genus Tuberaleyrodes is newly recorded from Borneo and Sulawesi. An identification key to puparia of Tuberaleyrodes species so far described is provided along with the countries of present records. Four plants families viz., Annonaceae, Fabaceae, Myristicaceae and Pentaphylacaeae are recorded as new hosts for Tuberaleyrodes species. New host plant records are indicated.

Assessing compatibility of Isaria fumosorosea and buprofezin for mitigation of Aleurodicus rugioperculatus (Hemiptera: Aleyrodidae) - an invasive pest in the Florida landscape

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A significant reduction in Rugose spiraling whitefly (RSW) population was reported for more than 5 weeks in buprofezin alone and more than 7 weeks in the combination treatments. In fall 2014 and summer 2015, the mean whitefly mortality observed during the 10 week assessment period were 52.4 and 42....

Female-induced increase of host-plant volatiles enhance specific attraction of aphid male Dysaphis plantaginea (Homoptera: Aphididae) to the sex pheromone

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Tol, van R.W.H.M.; Helsen, H.H.M.; Griepink, F.C.; Kogel, de W.J.

2009-01-01

All aphid species studied so far share the same sex pheromone components, nepetalactol and nepetalactone. Variation by different enantiomers and blends of the two components released by different aphid species are limited and can only partially explain species-specific attraction of males to

Resistance and susceptibility of alfalfa (Medicago sativa L.) cultivars to the aphid Therioaphis maculata (Homoptera:Aphididae): insect biology and cultivar evaluation

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ALEXANDRE DE ALMEIDA E SILVA; ELENICE MOURO VARANDA; JOS(E) RICARDO BAROSELA

2006-01-01

Biology of the aphid Therioaphis maculata was studied on alfalfa (Medicago sativa L.), including four resistant (Mesa-Sirsa, CUF101, Baker and Lahontan) and two susceptible (ARC and Caliverde) alfalfa cultivars, and one of the most cropped Brazilian cultivars, Crioula. Under controlled conditions, antibiosis (i.e., reduced longevity, fecundity and increased mortality of the aphid) was observed mainly on the resistant alfalfa cultivars,except on Lahontan. Crioula seemed to be tolerant to aphids. Present data support geographic limitation usage of cultivars, and we suggest Baker and Mesa-Sirsa as sources of antibiosis,and provide biological information of a tropical T. maculata biotype on alfalfa.

Cosmopsaltria halmaherae n. sp. endemic to Halmahera, Maluku, Indonesia (Homoptera, Cicadidae). The relationship of cicadas of Maluku Utara and Maluku Selatan

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Duffels, J.P.

1988-01-01

Cosmopsaltria halmaherae n. sp. is described from Halmahera, Maluku and placed in the C. doryca group. The characters of this group are reconsidered and the relationships of its members are discussed. The C. doryca group and two other monophyletic groups of cicadas demonstrate a vicariant

New species of the family Triozidae (Homoptera: Psylloidea) from China, and the first record of Psylloidea as host of Braconidae (Hymenoptera)

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Li, F.; Achterberg, van C.; He, J.

2000-01-01

Two new species of Triozidae (Psylloidea) from China producing sphere-shaped leaf galls on Ficus hainanensis Merr. & Shun., are illustrated and described. For the first time Psylloidea are reported as host of a species of Braconidae. The parasitoid belonging to the genus Bracon Fabricius, 1804, is

A reliable bioassay procedure to evaluate per os toxicity of Bacillus thuringiensis strains against the rice delphacid, Tagosodes orizicolus (Homoptera: Delphacidae

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Rebeca Mora

2007-06-01

Full Text Available A reliable bioassay procedure was developed to test ingested Bacillus thuringiensis (Bt toxins on the rice delphacid Tagosodes orizicolus. Initially, several colonies were established under greenhouse conditions, using rice plants to nurture the insect. For the bioassay, an in vitro feeding system was developed for third to fourth instar nymphs. Insects were fed through Parafilm membranes on sugar (10 % sucrose and honey bee (1:48 vol/vol solutions, observing a natural mortality of 10-15 % and 0-5 %, respectively. Results were reproducible under controlled conditions during the assay (18±0.1 °C at night and 28±0.1 °C during the day, 80 % RH and a 12:12 day:light photoperiod. In addition, natural mortality was quantified on insect colonies, collected from three different geographic areas of Costa Rica, with no significant differences between colonies under controlled conditions. Finally, bioassays were performed to evaluate the toxicity of a Bt collection on T. orizicolus. A preliminary sample of twenty-seven Bt strains was evaluated on coarse bioassays using three loops of sporulated colonies in 9 ml of liquid diet, the strains that exhibited higher percentages of T. orizicolus mortality were further analyzed in bioassays using lyophilized spores and crystals (1 mg/ml. As a result, strains 26-O-to, 40-X-m, 43S-d and 23-O-to isolated from homopteran insects showed mortalities of 74, 96, 44 and 82 % respectively while HD-137, HD-1 and Bti showed 19, 83 and 95 % mortalities. Controls showed mortalities between 0 and 10 % in all bioassays. This is the first report of a reliable bioassay procedure to evaluate per os toxicity for a homopteran species using Bacillus thuringiensis strains. Rev. Biol. Trop. 55 (2: 373-383. Epub 2007 June, 29.Se desarrolló una metodología de bioensayo para evaluar toxinas de Bacillus thuringiensis (Bt ingeridas por Tagosodes orizicolus, plaga del arroz y vector del virus de la hoja blanca. Se establecieron colonias del insecto en condiciones de invernadero usando plantas de arroz como alimento. Para el bioensayo, se desarrolló un sistema de alimentación in vitro para ninfas de tercer y cuarto estadío. Los insectos se alimentaron de soluciones de miel de abeja (1:48 vol/vol y sacarosa (10 % a través de membranas de Parafilm. Se observaron mortalidades del 10-15 % y 0-5 %, respectivamente, en ambas dietas. Los resultados fueron reproducibles en condiciones controladas de humedad y temperatura (18±0.1 °C de noche y 28±0.1 °C de día, 80 % H.R y a 12:12 fotoperíodo día:noche. Asimismo, se analizó la mortalidad natural de los insectos según su procedencia, sin embargo, no se observaron diferencias significativas en condiciones controladas. Finalmente, se elaboraron bioensayos para evaluar la toxicidad de una colección de cepas de Bt contra T. orizicolus. Se evaluó preliminarmente, una submuestra de 27 cepas de Bt en bioensayos burdos usando tres asadas como inóculo para 9 ml de dieta líquida. Posteriormente, las cepas que mostraron los mayores porcentajes de mortalidad se evaluaron en bioensayos usando esporas y cristales liofilizados (1 mg/ml. Como resultado, las cepas aisladas a partir de homópteros 26-O-to, 40-X-m, 43-S-d y 23-O-to mostraron mortalidades de 74, 96, 44 y 82 % respectivamente, mientras que las HD-137, HD-1 y Bti mostraron 19, 83 y 95 % de mortalidad. Los controles presentaron mortalidades de 0 y 10 % en los bioensayos. Este es el primer informe de un bioensayo para evaluar la toxicidad de cepas de Bt utilizando la especie T. orizicolus.