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Sample records for tabaci homoptera aleyrodidae

  1. Comparative efficacy of some insecticides against cotton whitefly, bemisia tabaci (gennadius) (homoptera: aleyrodidae) under natural field conditions

    International Nuclear Information System (INIS)

    Nadeem, M.K.; Hasnain, M.; Ahmed, S.; Ashfaq, M.

    2011-01-01

    Comparative efficacy of five commonly used insecticides viz., acetamiprid, buprofezin, diafenthiuron, imidacloprid and endosulfan against nymph and adult population of cotton whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) under natural field conditions has been studied. Results showed that buprofezin was the most effective insecticide against nymph population of whitefly among the tested insecticides where nymphal population of B. tabaci was 0.2/leaf after 24h spray as compared to 1.9/leaf in control. Acetamiprid was the most effective against adult population of whitefly (0.3 to 1.3/leaf post 72 h spray, as compared to control with 6.9 to 8.2/leaf) followed by diafenthiuron and imidaclopirid. whereas, endosulfan was found to be the least effective on both populations as adult and nymph of whitefly. From the tested insecticides, acetamaprid gave effective control of both nymph and adult population of B. tabaci. (author)

  2. Pengaruh Jenis Perangkap Sintetis Untuk Mengendalikan Hama Kutu Putih (Bemisia tabaci Genn.) (Homoptera: Aleyrodidae) Pada Tanaman Tembakau Deli (Nicotiana tabacum L.)

    OpenAIRE

    Nasution, Maimunah R.

    2010-01-01

    Maimunah R. Nasution, 2010. ”The Effect of Kinds Sintetic Traps to Control Pest of White Fly (Bemisia tabaci Genn.) (Homoptera: Aleyrodidae) in Tobacco Plantation (Nicotiana tabacum L.)”. This Research has been done in BPTTD Sampali, Deli Serdang, approximately ± 25 m from the sea surface. The aim of this research was to know the effect of kinds sintetic traps to control pest white fly (Bemisia tabaci Genn.) in Tobacco Plantation (Nicotiana tabacum L.). The parameters which observed were amou...

  3. Actividad fagodisuasiva de las plantas Tithonia diversifolia y Montanoa hibiscifolia (Asteraceae sobre adultos del insecto plaga Bemisia tabaci (Homoptera: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Gina Bagnarello

    2009-12-01

    Full Text Available Bemisia tabaci (Gennadius (Homoptera: Aleyrodidae es una plaga polífaga, cosmopolita y de gran relevancia mundial, sobre todo como vector de virus en numerosos cultivos, por lo que sería deseable un enfoque preventivo para su manejo. En tal sentido, podría recurrirse a la utilización de sustancias repelentes o disuasivas, algunas de ellas presentes en plantas tropicales, lo cual contribuiría al aprovechamiento de la rica biodiversidad mesoamericana. Por tanto, se evaluó la posible actividad fagodisuasiva sobre los adultos de B. tabaci de dos especies silvestres de la familia Asteraceae: titonia (Tithonia diversifolia (Hemsl. A. Gray y tora (Montanoa hibiscifolia Benth.. Para ello, en condiciones de invernadero se evaluaron los extractos crudos y cuatro fracciones (hexano, diclorometano, acetato de etilo y metanol de ambas especies, a los cuales se les hizo un análisis fitoquímico (tamizaje el cual permitió determinar cuáles metabolitos presentes en T. diversifolia y M. hibiscifolia podrían causar fagodisuasión en B. tabaci. Se realizaron dos tipos de experimentos: de escogencia restringida y de escogencia irrestricta. En los primeros, cada fracción se evaluó a cuatro dosis (0.1, 0.5, 1.0 y 1.5% v/v, y se comparó con cuatro tratamientos testigo: aceite agrícola, endosulfán, un emulsificante (Citowett y un testigo absoluto (agua. Se asperjaron plantas de tomate colocadas dentro de jaulas de manga, donde se liberaron 50 adultos de B. tabaci. Para determinar si existía fagodisuasión se utilizó como criterio el número de adultos posados a las 48h. Para el experimento de escogencia irrestricta se utilizaron las dos concentraciones más altas (1.0 y 1.5% del extracto crudo de cada especie y se compararon con el aceite agrícola y agua. Los extractos crudos de titonia y tora causaron fagodisuasión, y para ambas especies la fracción de metanol fue la que más sobresalió. En conclusión, los resultados obtenidos en los bioensayos

  4. Species and endosymbiont diversity of Bemisia tabaci (Homoptera: Aleyrodidae) on vegetable crops in Senegal.

    Science.gov (United States)

    Hélène, Delatte; Rémy, Baudin; Nathalie, Becker; Anne-Laure, Girard; Traoré, Ramatoulaye Sidebe; Jean-Michel, Lett; Bernard, Reynaud

    2015-03-01

    Bemisia tabaci-transmitted geminiviruses are one of the major threats on cassava and vegetable crops in Africa. However, to date, few studies are available on the diversity of B. tabaci and their associated endosymbionts in Africa. More than 28 species have been described in the complex of B. tabaci cryptic species; among them, 2 are invasive pests worldwide: MED and MEAM1. In order to assess the species diversity of B. tabaci in vegetable crops in Senegal, several samplings in different localities, hosts and seasons were collected and analyzed with nuclear (microsatellite) and mitochondrial (COI) markers. The bacterial endosymbiont community was also studied for each sample. Two species were detected: MED Q1 and MEAM1 B. Patterns of MED Q1 (dominance on most of the samples and sites, highest nuclear and mitochondrial diversity and broader secondary endosymbiont community: Hamiltonella, Cardinium, Wolbachia and Rickettsia), point toward a predominant resident begomovirus vector group for MED Q1 on market gardening crops. Furthermore, the lower prevalence of the second species MEAM1 B, its lower nuclear and mitochondrial diversity and a narrower secondary endosymbiont community (Hamiltonella/Rickettsia), indicate that this genetic group is exotic and results from a recent invasion in this area. © 2014 Institute of Zoology, Chinese Academy of Sciences.

  5. Conservation of predatory arthropods in cotton: role of action thresholds for Bemisia tabaci (Homoptera: Aleyrodidae).

    Science.gov (United States)

    Naranjo, S E; Ellsworth, P C; Chu, C C; Henneberry, T J

    2002-08-01

    Studies were conducted in 1994 and 1995 to examine the effects of a range of action thresholds for managing Bemisia tabaci (Gennadius) Biotype B (= B. argentifolii Bellows & Perring) with insecticides in cotton on populations of arthropod predators in Imperial Valley, CA, and Maricopa, AZ. Application of insecticides significantly reduced population densities of spiders, Geocoris punctipes (Say), G. pallens (Stål), Orius tristicolor (White), Nabis alternatus Parshley, Zelus renardii Kolenati, Hippodamia convergens Guerin-Méneville, Spanogonicus albofasciatus (Reuter), Drapetis sp., and Chrysoperla carnea Stephens in one or both years and sites compared with untreated controls. Use of higher B. tabaci thresholds conserved some species and groups relative to lower thresholds. Stepwise regression analyses indicated that reductions in predator populations were generally influenced more strongly by the timing of the first insecticide application than by the total number of sprays necessary to maintain suppression of the pest below any given action threshold. A predation index, which weights the importance of each predator species based on their known frequency of predation on B. tabaci and another key pest, Pectinophora gossypiella (Saunders), was developed and analyzed. Patterns were similar to results based on changes in abundance alone, but the index generally revealed less severe effects of insecticides on overall predator function. The current action threshold for conventional insecticidal control of B. tabaci in Arizona and southern California is five adults per leaf. Results here suggest that predator conservation may be enhanced by raising the initial threshold to delay the first application or initially using more selective materials such as insect growth regulators.

  6. Effets biocides des alcaloïdes, des saponines et des flavonoïdes extraits de Capsicum frutescens L. (Solanaceae sur Bemisia tabaci (Gennadius (Homoptera : Aleyrodidae

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    Blenzar A.

    2005-01-01

    Full Text Available Biocide effects of alkaloids, saponins and flavonoids extracted from Capsicum frutescens L. (Solanaceae on Bemisia tabaci (Gennadius (Homoptera: Aleyrodidae. In an attempt to elaborate a strategy of integrated pest management on vegetable crops in Morocco, insecticidal activities of alkaloids, saponins and flavonoids extracted from Capsicum frutescens L. fruits against eggs and adults of Bemisia tabaci infesting tomato plants, Lycopersicon esculentum Mill. var. Daniella, were carried out under controlled conditions. Alkaloids, saponins and flavonoids, dissolved in ethanol at 1%, were tested at 0, 5, 10 and 20 g.l-1. The three compounds affected egg and adult survival, significantly. The mortality of embryo and adult varied according to the compound considered and for each compound according to concentration and exposure duration. For eggs, the corrected mortality varied from 35 to 59% for alkaloids, 14 to 31% for saponins and 10 to 14% for flavonoids. In adults, the mortalities were spread from 29% to 86%, 14 to 48% and 6 to 29% with alkaloids, saponins and flavonoids, respectively. Significant correlation between egg and adult mortality, due to the compounds tested, were observed. However, eggs required higher concentrations than adults; the LC50 was 13.78 vs. 6.83 g.l-1 for alkaloids, 98.63 vs. 32.28 g.l-1 for saponins and nontoxic vs. 120.65 g.l-1 for the flavonoids. Therefore, alkaloids were shown more effective against B. tabaci than saponins or flavonoids. However, the LT50 estimated for compounds, killing more than 50% of the population studied, was sufficient for viruliferous adults to inoculate TYLCV to plants before they died. The use of these compounds in integrated pest management merit further study.

  7. Adult attractiveness and oviposition preference of Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae) B-biotype in cotton genotypes

    OpenAIRE

    Boiça Júnior,Arlindo Leal; Campos,Zeneide Ribeiro; Lourenção,André Luiz; Campos,Alcebíades Ribeiro

    2007-01-01

    The silverleaf whitefly Bemisia tabaci B-biotype is an important pest of cotton; it affects plant vigour, transmits geminivirus and reduces lint quality. In order to evaluate the resistance of cotton genotypes, Gossypium hirsutum (L.), to the whitefly Bemisia tabaci B-biotype, both free-choice and no-choice attractiveness and non-preference for oviposition tests were carried out in a shade house, at room temperature. Low attractiveness to adults of this whitefly was observed for plants of gen...

  8. Functional and numerical responses of Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) parasitizing cotton whitefly, Bemisia tabaci Gennadius (Homoptera: Aleyrodidae).

    Science.gov (United States)

    Sohani, Nooshin Zandi; Shishehbor, Parviz; Kocheili, Farhan

    2008-04-01

    Laboratory experiments were conducted to measure the functional and numerical responses of Eretmocerus mundus Mercet parasitizing cotton whitefly, Bemisia tabaci Gennadius. Parasitoids were isolated singly for 24 h in 5 cm petri dishes with either 5, 10, 20, 40, 60 or 100 second nymphal stages of B. tabaci. Results showed a typical type II functional response, with up to 43.2 hosts attacked when 100 hosts were provided. The rate of attack and handling time were 0.0465 and 0.3341 days, respectively. At above mentioned densities, the parasitoids lived an average of approximately 4 days. At host densities of < or =20 host/day, the total number of eggs laid was limited by the number of hosts available. Total fecundity was highest with an average of 196 eggs/female at density 100.

  9. 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

  10. Biología de Eretmocerus mundus (Hymenoptera: Aphelinidae, parasitoide del complejo Bemisia tabaci (Homoptera: Aleyrodidae, en condiciones de laboratorio Biology of Eretmocerus mundus (Hymenoptera: Aphelinidae, parasitoid of Bemisia tabaci complex (Homoptera: Aleyrodidae under laboratory conditions

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    Yerlin Chacón Castro

    2010-06-01

    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 (Ro 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.The estimation of biological attributes of natural enemies prior to its use in the field is an important tool in a biological control program. The objective of the present paper was to evaluate the main biological parameters of Eretmocerus mundus Mercet, a parasitoid of Bemisia tabaci (Gennadius, under controlled laboratory conditions. Parasitoid survival, female longevity, fecundity, sex rate, intrinsic rate of natural increase (r m, net reproductive rate (Ro and generational time (T were studied using life tables, with pepper (Capsicum annuum L. and tomato (Solanum lycopersicum L. as host plants. Results

  11. 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

  12. 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.

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

    Science.gov (United States)

    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.

  14. Effects of double-stranded RNA on virulence of Paecilomyces fumosoroseus (Deuteromycotina: Hyphomycetes against the silverleaf whitefly, Bemisia tabaci strain B (Homoptera: Aleyrodidae

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    Andréia Cristiane Souza Azevedo

    2000-03-01

    Full Text Available Bands of double-stranded RNA (dsRNA were detected in three out of twelve isolates of Paecilomyces fumosoroseus. Identity of these bands was confirmed by RNAse, DNAse and S1 nuclease treatments. The cure of dsRNA for one isolate (P92 was successfully carried out for a single conidium subculture. Isogenic strains, with or without dsRNA, were submitted to virulence tests against the whitefly Bemisia tabaci strain B. In contrast to findings for some phytopathogenic fungi, these dsRNA fragments did not cause hypovirulence in P. fumosoroseus.Bandas de dsRNA foram detectadas em três dos doze isolados de Paecilomyces fumosoroseus. A identidade destas bandas foi provada através de tratamentos com RNAse, DNAse e S1 nuclease. A cura do dsRNA para um dos isolados (P92 foi obtida através do isolamento de colônias monospóricas. Linhagens isogênicas, com e sem dsRNA, foram submetidas ao teste de virulência contra a mosca branca Bemisia tabaci biotipo B. Ao contrário do que ocorre para vários fungos fitopatogênicos, os fragmentos de dsRNA não causaram hipovirulência em P. fumosoroseus.

  15. Populations of Bemisia tabaci (Homoptera: Aleyrodidae) on cotton grown in open-top field chambers enriched with CO/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Butler, G.D. Jr.; Kimball, B.A.; Mauney, J.R.

    1985-02-01

    Atmospheric CO/sub 2/ levels are anticipated to rise from the current ambient level of ca. 350 ..mu..l/liter to 500-600 ..mu..l/liter in the next 50 to 75 years. Plant scientists are artificially enhancing the CO/sub 2/ environment of crop plants to increase photosynthesis, which is currently limited by inadequate levels of CO/sub 2/. It is not known how increases of CO/sub 2/ might affect consumers in the food chain. Population levels of sweet potato whitefly (SPWF), Bermisiaa tabaci (Gennadius), were assessed with sticky traps placed in a field experiment wherein cotton was grown in open-top field chambers that were enriched with CO/sub 2/ at levels approaching 200% ambient concentration levels. Although trapping started at the first of June, only an occasional SPWF was caught until early August. At that time populations began to increase at an exponential rate similar to that observed in commercial cotton fields in Arizona and California in previous years. There was no difference in rate of buildup of SPWF in ambient and CO/sub 2/-enriched chambers in either wet or dry irrigation treatment. Thus, it seems that raised CO/sub 2/ levels, either natural or artificial, do not affect SPWF populations.

  16. Adult attractiveness and oviposition preference of Bemisia tabaci (Genn. (Homoptera: Aleyrodidae B-biotype in cotton genotypes Atratividade de adultos e preferência para oviposição de Bemisia tabaci (Genn. (Homoptera: Aleyrodidae biótipo B em genótipos de algodoeiro

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    Arlindo Leal Boiça Júnior

    2007-01-01

    Full Text Available The silverleaf whitefly Bemisia tabaci B-biotype is an important pest of cotton; it affects plant vigour, transmits geminivirus and reduces lint quality. In order to evaluate the resistance of cotton genotypes, Gossypium hirsutum (L., to the whitefly Bemisia tabaci B-biotype, both free-choice and no-choice attractiveness and non-preference for oviposition tests were carried out in a shade house, at room temperature. Low attractiveness to adults of this whitefly was observed for plants of genotypes Fabrika, CNPA Ita 90, Makina, Coodetec 407, and IAC 01-639 CPA 02-24, which may represent a resistance component of these genetic materials to the insect. Genotypes BRS Aroeira, Coodetec 406, Fabrika, and Coodetec 401 presented the non-preference-for-oviposition type of resistance in the free-choice and no-choice tests. The numbers of trichomes and gossypol glands per cm² were not suitable to evaluate non-preference for oviposition of whitefly adults on cotton genotypes.Considerada importante praga do algodoeiro, a mosca-branca Bemisia tabaci biótipo B pode através de sua alimentação, diminuir o vigor das plantas, trasmitir vírus e prejudicar a qualidade da fibra. Visando avaliar a resistência de genótipos de algodoeiro, Gossypium hirsutum (L., à mosca-branca Bemisia tabaci biótipo B, realizaram-se testes de atratividade e não-preferência para oviposição, com e sem chance de escolha, em telado, a temperatura ambiente. Verificou-se baixa atratividade das plantas dos genótipos Fabrika, CNPA Ita 90, Makina, Coodetec 407 e IAC 01-639 CPA 02-24 a adultos dessa mosca-branca, o que pode representar um componente de resistência destes materiais genéticos ao inseto. Os genótipos BRS Aroeira, Coodetec 406, Fabrika e Coodetec 401 apresentaram resistência do tipo não-preferência para oviposição, nos testes com e sem chance de escolha. Os números de tricomas e de glândulas de gossipol por cm² não foram adequados para se avaliar a n

  17. Paraleyrodes minei Iaccarino 1990 (Homoptera: Aleyrodidae, new specie for Italy, on Citrus aurantium L., 1758

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    Fabio M. Iaccarino

    2011-04-01

    Full Text Available The nesting whitefly Paraleyrodes minei Iaccarino 1990 (Homoptera: Aleyrodidae was found on leaves of sour orange tree Citrus aurantium L., 1758, in the Gussone Park of the Faculty of Agriculture, of the U niversity of N aples “Federico II”, at Portici, Italy.

  18. Facultative symbiont Hamiltonella confers benefits to Bemisia tabaci (Hemiptera: Aleyrodidae), an invasive agricultural pest worldwide.

    Science.gov (United States)

    Su, Qi; Oliver, Kerry M; Pan, Huipeng; Jiao, Xiaoguo; Liu, Baiming; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Xu, Baoyun; White, Jennifer A; Zhou, Xuguo; Zhang, Youjun

    2013-12-01

    Bacterial symbionts infect most insect species, including important pests such as whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), and often exert important effects on host ecology. The facultative symbiont Hamiltonella is found at high frequencies in the B. tabaci MED (type: Mediterranean-MED) in China. The prevalence of this symbiont in natural populations suggests beneficial effects of infection or manipulation of host reproduction. To date, however, no empirical studies on the biological role of Hamiltonella on the host B. tabaci have been reported. Here, we investigated the effects of Hamiltonella infection on the sex ratio and several fitness parameters in B. tabaci MED by comparing Hamiltonella-infected whiteflies with Hamiltonella-free ones. We found that Hamiltonella-infected whiteflies produced significantly more eggs, exhibited significantly higher nymphal survival, faster development times, and larger adult body size in comparison with Hamiltonella-free whiteflies, while no evidence of reproductive manipulation by Hamiltonella were found in B. tabaci MED. In conclusion, Hamiltonella infection substantially enhanced B. tabaci MED performance. This beneficial role may, at least partially, explain the high prevalence of Hamiltonella in B. tabaci MED populations and may also contribute to their effectiveness in spread of the plant pathogens tomato yellow leaf curl virus.

  19. Characterization of a newly discovered symbiont of the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Bing, Xiao-Li; Yang, Jiao; Zchori-Fein, Einat; Wang, Xiao-Wei; Liu, Shu-Sheng

    2013-01-01

    Bemisia tabaci (Hemiptera: Aleyrodidae) is a species complex containing >28 cryptic species, some of which are important crop pests worldwide. Like many other sap-sucking insects, whiteflies harbor an obligatory symbiont, "Candidatus Portiera aleyrodidarum," and a number of secondary symbionts. So far, six genera of secondary symbionts have been identified in B. tabaci. In this study, we report and describe the finding of an additional bacterium in the indigenous B. tabaci cryptic species China 1 (formerly known as B. tabaci biotype ZHJ3). Phylogenetic analysis based on the 16S rRNA and gltA genes showed that the bacterium belongs to the Alphaproteobacteria subdivision of the Proteobacteria and has a close relationship with human pathogens of the genus Orientia. Consequently, we temporarily named it Orientia-like organism (OLO). OLO was found in six of eight wild populations of B. tabaci China 1, with the infection rate ranging from 46.2% to 76.8%. Fluorescence in situ hybridization (FISH) of B. tabaci China 1 in nymphs and adults revealed that OLOs are confined to the bacteriome and co-occur with "Ca. Portiera aleyrodidarum." The vertical transmission of OLO was demonstrated by detection of OLO at the anterior pole end of the oocytes through FISH. Quantitative PCR analysis of population dynamics suggested a complex interaction between "Ca. Portiera aleyrodidarum" and OLO. Based on these results, we propose "Candidatus Hemipteriphilus asiaticus" for the classification of this symbiont from B. tabaci.

  20. Quantifying Conservation Biological Control for Management of Bemisia tabaci (Hemiptera: Aleyrodidae) in Cotton.

    Science.gov (United States)

    Vandervoet, Timothy F; Ellsworth, Peter C; Carrière, Yves; Naranjo, Steven E

    2018-03-13

    Conservation biological control can be an effective tactic for minimizing insect-induced damage to agricultural production. In the Arizona cotton system, a suite of generalist arthropod predators provides critical regulation of Bemisia tabaci Gennadius (MEAM1) (Hemiptera: Aleyrodidae) and other pests. Arthropod predator and B. tabaci populations were manipulated with a range of broad-spectrum and selective insecticide exclusions to vary predator to prey interactions in a 2-yr field study. Predator to prey ratios associated with B. tabaci densities near the existing action threshold were estimated for six predator species found to be negatively associated with either adult and/or large nymphs of B. tabaci [Misumenops celer (Hentz) (Araneae: Thomisidae), Drapetis nr divergens (Diptera: Empididae), Geocoris pallens Stäl (Hemiptera: Geocoridae), Orius tristicolor (White) (Hemiptera: Anthocoridae), Chrysoperla carnea s.l. (Neuroptera: Chrysopidae), and Collops spp. (Coleoptera: Melyridae)] with the first three most consistently associated with declining B. tabaci densities. Ratios ranged from 1 M. celer per 100 sweeps to 1 B. tabaci adult per leaf to 44 D. nr. divergens per 100 sweeps to 1 large nymph per leaf disk. These ratios represent biological control informed thresholds that might serve as simple-to-use decision tool for reducing risk in the current B. tabaci integrated pest management strategy. The identification of key predators within the large, flexible food web of the cotton agro-ecosystem and estimation of predator to B. tabaci ratios clarifies the role of key predators in B. tabaci suppression, yielding potential decision-making advantages that could contribute to further improving economic and environmental sustainability of insect management in the cotton system.

  1. Cryptic Species Identification and Composition of Bemisia tabaci (Hemiptera: Aleyrodidae) Complex in Henan Province, China.

    Science.gov (United States)

    Jiu, Min; Hu, Jian; Wang, Lun-Ji; Dong, Jun-Feng; Song, Yue-Qin; Sun, Hui-Zhong

    2017-05-01

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex, causing significant crop losses in China during the last decade. Although knowledge of cryptic species composition and dynamics within B. tabaci complex is critical for developing sustainable pest management strategies, limited information is available on this pest in the Henan province of China. A systematic survey of the cryptic species composition and distribution of B. tabaci complex in different locations of Henan province was conducted in 2012. The results of RAPD-PCR and the gene for the mitochondrial cytochrome oxidase subunit-1 (mtCOI) based phylogenetic relationships established using Bayesian method indicated there were four known cryptic species MEAM1, MED, Asia II 3, Asia II 9 and a new cryptic species named China 6 in Henan province. In the survey, the invasive cryptic species MED and MEAM1 were found to be predominant with wide spread distribution across the surveyed regions. On the contrary, the indigenous B. tabaci cryptic species including Asia II 3, Asia II 9 and China 6 remained with low prevalence in some surveyed regions. Cryptic species MEAM1 and MED have not completely displaced the native B. tabaci in Henan province. This current study for the first time unifies our knowledge of the diversity and distribution of B. tabaci across Henan province of China. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  2. Spatiotemporal Dynamics of Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) in Commercial Watermelon Crops.

    Science.gov (United States)

    Lima, Carlos H O; Sarmento, Renato A; Galdino, Tarcísio V S; Pereira, Poliana S; Silva, Joedna; Souza, Danival J; Dos Santos, Gil R; Costa, Thiago L; Picanço, Marcelo C

    2018-04-16

    Spatiotemporal dynamics studies of crop pests enable the determination of the colonization pattern and dispersion of these insects in the landscape. Geostatistics is an efficient tool for these studies: to determine the spatial distribution pattern of the pest in the crops and to make maps that represent this situation. Analysis of these maps across the development of plants can be used as a tool in precision agriculture programs. Watermelon, Citrullus lanatus (Thunb.) Matsum. and Nakai (Cucurbitales: Cucurbitaceae), is the second most consumed fruit in the world, and the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most important pests of this crop. Thus, the objective of this work was to determine the spatiotemporal distribution of B. tabaci in commercial watermelon crops using geostatistics. For 2 yr, we monitored adult whitefly densities in eight watermelon crops in a tropical climate region. The location of the samples and other crops in the landscape was georeferenced. Experimental data were submitted to geostatistical analysis. The colonization of B. tabaci had two patterns. In the first, the colonization started at the outermost parts of the crop. In the second, the insects occupied the whole area of the crop since the beginning of cultivation. The maximum distance between sites of watermelon crops in which spatial dependence of B. tabaci densities was observed was 19.69 m. The adult B. tabaci densities in the eight watermelon fields were positively correlated with rainfall and relative humidity, whereas wind speed negatively affected whiteflies population.

  3. Mitigating trans-boundary movement of Bemisia tabaci (Hemiptera: Aleyrodidae) on Mentha sp. by pre-shipping treaments of biopesticides

    Science.gov (United States)

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of several important crops including vegetables, cereals, fruits, and ornamentals grown worldwide. One important mode of its dispersal is through the trans-boundary movement of infested plant materials. In order to prevent the sprea...

  4. Sublethal effects of some synthetic and botanical insecticides on Bemisia tabaci (Hemiptera: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Esmaeily Saeideh

    2014-07-01

    Full Text Available In addition to direct mortality caused by insecticides, some biological traits of insects may also be affected by sublethal insecticide doses. In this study, we used the age-stage, two-sex life table method to evaluate the sublethal effects of the four synthetic insecticides: abamectin, imidacloprid, diazinon, and pymetrozin as well as the botanical insecticide taken from Calotropis procera (Asclepiadaceae extract, on eggs of the cotton whitefly, Bemisia tabaci (Hem.: Aleyrodidae. The lowest and highest survival rates and oviposition periods were observed in whiteflies treated by diazinon and imidacloprid, respectively. We found significant differences in the net reproductive rate (R0, the intrinsic rate of increase (r, the finite rate of increase (?, and the gross reproductive rate (GRR among different insecticides. Altogether, our results showed that pymetrozin and C. procera induced the most sublethal effects, thus they may be suitable candidates for use in integrated pest management programs of B. tabaci.

  5. Sublethal effects of some botanical and chemical insecticides on the cotton whitefly, Bemisia tabaci (Hem: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Fatemeh Jafarbeigi

    2014-09-01

    Full Text Available In addition to direct mortalities caused by acute concentrations of insecticides, some biological traits of target pests may be also affected by sublethal doses. The cotton whitefly, Bemisia tabaci (Hem: Aleyrodidae is an important pest of a wide variety of agricultural crops across the world. The control of B. tabaci largely relies on wide application of chemical insecticides. In this study, we analyzed the life table parameters to evaluate the sublethal effect of three plant-derived insecticides (Fumaria parviflora (Fumariaceae, Teucrium polium (Lamiaceae, and Thymus vulgaris (Lamiaceae and two chemical insecticides (pymetrozin and neemarin on B. tabaci. The whiteflies were allowed to oviposit on plants infected with each of the five insecticides using leaf-dip method. The data were analyzed using the age-stage two-sex life table. We found significant differences in the gross reproductive rate (GRR, the net reproductive rat (R0, the intrinsic rate of increase (r and the finite rate of increase (λ of treated whiteflies compared to control. Our results showed that some biological traits of B. tabaci are affected by sub-lethal doses of the plant-derived extracts and that these effects are comparable to those of chemical insecticides. Given the detrimental effects of chemical insecticides on human, environment and non-target organisms, plant-derived insecticides may provide valuable environmentally friendly tools for pest management programs.

  6. Protecting Unrooted Cuttings From Bemisia tabaci (Hemiptera Aleyrodidae) During Propagation.

    Science.gov (United States)

    Krauter, Peter C; Heinz, Kevin M; Arthurs, Steven

    2017-07-01

    In North America, the sweetpotato whitefly, Bemisia tabaci Genn., is an important pest of greenhouse poinsettia. Growers have limited options to control this pest during propagation of cuttings, which are rooted under mist for several weeks. Early establishment of this pest increases the difficulty of managing the whitefly and retaining high aesthetic standard during the remaining crop production phase. We evaluated two neonicotinoids with translaminar activity, thiamethoxam (Flagship 25WG), and acetamiprid (TriStar 70 WSP), for control of B. tabaci pre-infested on unrooted cuttings propagated under mist. In an experimental greenhouse, both materials significantly reduced whitefly populations, providing an average reduction of 87.8% and 61.5% total recovered whitefly stages respectively, compared with controls. In another test, dipping cuttings in thiamethoxam (immersion treatment) did not improve control significantly, when compared with foliar sprays applied at label rate. In a commercial greenhouse operation, immersion treatments of thiamethoxam on pre-infested poinsettia cuttings maintained whiteflies at ≤ 0.02/plant, compared with up to 0.33/plant in untreated cuttings. Our data suggest that treating unrooted cuttings before or at the start of propagation can be part of an overall strategy for growers to manage whiteflies in poinsettia production. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  7. Diversity and Distribution of Cryptic Species of the Bemisia tabaci (Hemiptera: Aleyrodidae) complex in Pakistan.

    Science.gov (United States)

    Masood, Mariyam; Amin, Imran; Hassan, Ishtiaq; Mansoor, Shahid; Brown, Judith K; Briddon, Rob W

    2017-12-05

    Bemisia tabaci (Gennadius; Hempitera: Aleyrodidae) is considered to be a cryptic (sibling) species complex, the members of which exhibit morphological invariability while being genetically and behaviorally distinct. Members of the complex are agricultural pests that cause direct damage by feeding on plants, and indirectly by transmitting viruses that cause diseases leading to reduced crop yield and quality. In Pakistan, cotton leaf curl disease, caused by multiple begomovirus species, is the most economically important viral disease of cotton. In the study outlined here, the diversity and geographic distribution of B. tabaci cryptic species was investigated by analyzing a taxonomically informative fragment of the mitochondrial cytochrome c oxidase 1 gene (mtCOI-3'). The mtCOI-3' sequence was determined for 285 adult whiteflies and found to represent six cryptic species, the most numerous being Asia II-1 and Middle East Asia Minor 1 (MEAM-1), the later also referred to as the B-biotype, which was previously thought to be confined to Sindh province but herein, was also found to be present in the Punjab province. The endemic Asia I was restricted to Sindh province, while an individual in the Asia II-8 was identified in Pakistan for the first time. Also for the first time, samples were collected from northwestern Pakistan and Asia II-1 was identified. Results indicate that in Pakistan the overall diversity of B. tabaci cryptic species is high and, based on comparisons with findings from previous studies, the distribution is dynamic. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Non-invasive delivery of dsGST is lethal to the sweet potato whitefly, Bemisia tabaci (G.) (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Asokan, R; Rebijith, K B; Roopa, H K; Kumar, N K Krishna

    2015-02-01

    The sweet potato whitefly, Bemisia tabaci (G.) biotype B (Hemiptera: Aleyrodidae), is one of the most economically important pest, by being a dreaded vector of Geminiviruses, and also causes direct damage to the crops by sucking phloem sap. Glutathione S-transferase (GST) is a large family of multifunctional enzymes that play pivotal roles in the detoxification of secondary allelochemical produced by the host plants and in insecticide resistance, thus regulates insect growth and development. The objective of this study is to show the potential of RNA interference (RNAi) in the management of B. tabaci. RNAi is a sequence-specific gene silencing mechanism induced by double-stranded RNA (dsRNA) which holds tremendous potential in pest management. In this regard, we sequenced the GST from B. tabaci and synthesized approximately 500-bp dsRNA from the above and delivered through diet to B. tabaci. Real-time quantitative PCR (RT-qPCR) showed that continuous application of dsGST at 1.0, 0.5, and 0.25 μg/μl reduced mRNA expression levels for BtGST by 77.43, 64.86, and 52.95 % which resulted in mortality by 77, 59, and 40 %, respectively, after 72 h of application. Disruption of BtGST expression will enable the development of novel strategies in pest management and functional analysis of vital genes in B. tabaci.

  9. Establishment of papaya banker plant system for Parasitoid, Encarsia sophia (Hymenoptera: Aphilidae) against Bemisia tabaci (Hemiptera: Aleyrodidae) in greenhouse tomato production

    Science.gov (United States)

    The silverleaf whitefly, Bemisia tabaci biotype B (Gennadius) (Hemiptera:Aleyrodidae), is a key pest of tomato (Solanum lycopersicum L.) and other vegetable crops worldwide. To combat this pest, a non-crop banker plant system was evaluated that employs a parasitoid, Encarsia sophia (Girault & Dodd) ...

  10. [Occurrence of Stethorus (Stethotrus) minutalus Gordon & Chapin (Coleoptera: Coccinellidae) preying Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) on cotton plant in Brazil].

    Science.gov (United States)

    Silva, Leonardo D; Bonani, Jean P

    2008-01-01

    This report has the objective of registering, for the first time in Brazil, the predator Stethorus (Stethorus) minutalus Gordon & Chapin (Scymninae, Stethorini). Larvae and adults were observed feeding on eggs and nymphs of the whitefly Bemisia tabaci Gennadius biotype B (Hemiptera: Aleyrodidae), on cotton plants under greenhouse condition in Piracicaba, SP. Probably, this coccinelid is an introduced species in the Country.

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

    OpenAIRE

    Tello Paola; Cantor Fernando; Rodríguez Daniel; Cure José Ricardo

    2007-01-01

    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 mas...

  12. Transgenic Cotton-Fed Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Affects the Parasitoid Encarsia desantisi Viggiani (Hymenoptera: Aphelinidae) Development.

    Science.gov (United States)

    Pessoa, R; Rossi, G D; Busoli, A C

    2016-02-01

    Cotton cultivars expressing Cry proteins are widely used to control lepidopteran pests. The effects of transgenic plants containing insecticidal Cry proteins on non-target species must be comprehended for a better and rational use of this technology for pest management. We investigated the influence of the Bt cotton cultivars NuOPAL and FM 975 on biological parameters of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), a non-target pest of Bt cotton cultivars and on its parasitoid Encarsia desantisi Viggiani (Hymenoptera: Aphelinidae). The experiments were conducted in a climatized room, and the non-transgenic near isolines were used for rearing whiteflies as control hosts. The effects of the Bt cotton cultivars on the period of embryonic and larval development and the percentage of adult emergence of B. tabaci were assessed. The period required for embryonic, larval, and pupal development and the percentage of emergence and longevity of E. desantisi females were determined using Bt cotton-fed and non-Bt cotton-fed B. tabaci as hosts. Both Bt cotton cultivars resulted in a decrease of approximately 20% of adult emergence of B. tabaci. Differently, an increase of approximately 10% of adult emergence of E. desantisi was observed for parasitoids that used hosts fed with both Bt cotton cultivars. However, female parasitoid longevity decreased when their hosts were fed on Bt cotton cultivars. Our data suggest that the use of Bt cotton cultivars in association with the biological control agent E. desantisi could be functional for the management of B. tabaci in Bt cotton crops.

  13. Effects of high-gossypol cotton on the development and reproduction of Bemisia tabaci (Hemiptera: Aleyrodidae) MEAM1 cryptic species.

    Science.gov (United States)

    Guo, Jian-Ying; Wu, Gang; Wan, Fang-Hao

    2013-06-01

    Use of plant secondary metabolic compounds is an important method for insect pest control. In this study, the survival, development, and reproduction of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) MEAM1 cryptic species were compared over two consecutive generations on three cotton cultivars of different gossypol levels. Both cotton cultivar and generation significantly affected the fitness of the whitefly. In both generations, the immature development times on the low-gossypol cultivar ZMS13 were significantly longer than those on the high-gossypol cultivar M9101 or medium-gossypol cultivar HZ401. The female fecundity and rate of population increase of the whitefly ranked in the following order: ZMS13 > HZ401 > M9101. On each cultivar, the immature development time was shorter and the immature survival rate was higher in the second generation than those in the first generation. Rate of increase was also higher in the second generation. These results demonstrated that the fitness of B. tabaci MEAM1 cryptic species on the low-gossypol cotton cultivar ZMS13 was higher than that on the medium- or high-gossypol cultivar. The comparison of the life histories of B. tabaci MEAM1 cryptic species on different cotton varieties is important for the development of an integrated pest management program of the whitefly by using plant secondary metabolic compounds.

  14. Analysis of Species, Subgroups, and Endosymbionts of Bemisia tabaci (Hemiptera: Aleyrodidae) From Southwestern Cotton Fields in Turkey.

    Science.gov (United States)

    Karut, Kamil; Mete Karaca, M; Döker, Ismail; Kazak, Cengiz

    2017-08-01

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most important insect pests worldwide including Turkey. Although there are substantial data regarding species composition of Turkish B. tabaci populations, the situation is still not clear and further investigations are needed. Therefore, in this study, species and subgroups of B. tabaci collected from cotton fields in southwestern part of Turkey (Antalya, Aydın, Denizli, and Muğla) were determined using microsatellite analysis, AluI-based mtCOI polymerase chain reaction-random length polymorphism, and sequencing. Secondary endosymbionts were also determined using diagnostic species-specific PCR. Middle East Asia Minor 1 (MEAM1), Mediterranean (MED) Q1, and MED Q2 were the species and subgroups found in this study. The MED species (85.3%) were found to be more dominant than MEAM1. Species status of B. tabaci varied depending on the location. Although all samples collected from Aydın were found to be Q1, three species and subgroups were found in Muğla. Secondary endosymbionts varied according to species and subgroups. Arsenophonus was found only from Q2, while Hamiltonella was detected in MEAM1 and Q1. In addition, high Rickettsia and low Wolbachia infections were detected in MEAM1 and Q1 populations, respectively. In conclusion, for the first time, we report the presence and symbiotic communities of Q1 from Turkey. We also found that the symbiont complement of the Q1 is more congruent with Q1 from Greece than other regions of the world, which may have some interesting implications for movement of this invasive subgroup. © 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.

  15. Spread of the spiraling white fly Aleurodicus dispersus (Homoptera ...

    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 Northwest and Central Nigeria.

  16. Cassava whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in East African farming landscapes: a review of the factors determining abundance.

    Science.gov (United States)

    Macfadyen, S; Paull, C; Boykin, L M; De Barro, P; Maruthi, M N; Otim, M; Kalyebi, A; Vassão, D G; Sseruwagi, P; Tay, W T; Delatte, H; Seguni, Z; Colvin, J; Omongo, C A

    2018-02-13

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest species complex that causes widespread damage to cassava, a staple food crop for millions of households in East Africa. Species in the complex cause direct feeding damage to cassava and are the vectors of multiple plant viruses. Whilst significant work has gone into developing virus-resistant cassava cultivars, there has been little research effort aimed at understanding the ecology of these insect vectors. Here we assess critically the knowledge base relating to factors that may lead to high population densities of sub-Saharan African (SSA) B. tabaci species in cassava production landscapes of East Africa. We focus first on empirical studies that have examined biotic or abiotic factors that may lead to high populations. We then identify knowledge gaps that need to be filled to deliver sustainable management solutions. We found that whilst many hypotheses have been put forward to explain the increases in abundance witnessed since the early 1990s, there are little published data and these tend to have been collected in a piecemeal manner. The most critical knowledge gaps identified were: (i) understanding how cassava cultivars and alternative host plants impact population dynamics and natural enemies; (ii) the impact of natural enemies in terms of reducing the frequency of outbreaks and (iii) the use and management of insecticides to delay the development of resistance. In addition, there are several fundamental methodologies that need to be developed and deployed in East Africa to address some of the more challenging knowledge gaps.

  17. Reproduction of the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) B biotype in maize fields (Zea mays L.) in Brazil.

    Science.gov (United States)

    Quintela, Eliane D; Abreu, Aluana G; Lima, Julyana F Dos S; Mascarin, Gabriel M; Santos, Jardel B Dos; Brown, Judith K

    2016-11-01

    Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) was observed to have completed its reproductive cycle from the egg to the adult on maize (Zea mays L.). Field and screenhouse studies were carried out to investigate the durability of this putative and unprecedented adaptation to a grass host. Analysis of the mitochondrial COI gene sequence identified the maize-associated B. tabaci as the exotic B biotype (major clade North Africa-Mediterranean-Middle East). Results showed that whiteflies migrated from soybean crops and successfully established in maize plants. Females exhibited a preference for oviposition primarily on the first and second leaves of maize, but were also able to colonise developing leaves. A high, natural infestation on maize (193.3 individuals, all developmental stages) was observed within a 7.1 cm 2 designated 'observation area'. Whiteflies collected from naturally infested maize leaves and allowed to oviposit on maize seedlings grown in a screenhouse developed from egg to adulthood in 28.6 ± 0.2 days. This is the first report of the B biotype completing its development on maize plants. This surprising anomaly indicates that the B biotype is capable of adapting to monocotyledonous host plants, and importantly, broadens the host range to include at least one species in the Poaceae. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

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

    Science.gov (United States)

    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.

  19. Sensitivity of Bemisia tabaci (Hemiptera: Aleyrodidae) to several new insecticides in China: effects of insecticide type and whitefly species, strain, and stage.

    Science.gov (United States)

    Xie, Wen; Liu, Yang; Wang, Shaoli; Wu, Qingjun; Pan, Huipeng; Yang, Xin; Guo, Litao; Zhang, Youjun

    2014-01-01

    Whitefly biotypes B and Q are the two most damaging members of the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex. Control of B. tabaci (and especially of Q) has been impaired by resistance to commonly used insecticides. To find new insecticides for B. tabaci management in China, we investigated the sensitivity of eggs, larvae, and adults of laboratory strains of B and Q (named Lab-B and Lab-Q) and field strains of Q to several insecticides. For eggs, larvae, and adults of B. tabaci and for six insecticides (cyantraniliprole, chlorantraniliprole, pyriproxyfen, buprofezin, acetamiprid, and thiamethoxam), LC50 values were higher for Lab-Q than for Lab-B; avermectin LC50 values, however, were low for adults of both Lab-Q and Lab-B. Based on the laboratory results, insecticides were selected to test against eggs, larvae, and adults of four field strains of B. tabaci Q. Although the field strains differed in their sensitivity to the insecticides, the eggs and larvae of all strains were highly sensitive to cyantraniliprole, and the adults of all strains were highly sensitive to avermectin. The eggs, larvae, and adults of B. tabaci Q were generally more resistant than those of B. tabaci B to the tested insecticides. B. tabaci Q eggs and larvae were sensitive to cyantraniliprole and pyriproxyfen, whereas B. tabaci Q adults were sensitive to avermectin. Field trials should be conducted with cyantraniliprole, pyriproxyfen, and avermectin for control of B. tabaci Q and B in China. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  20. The suitability of biotypes Q and B of Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae at different nymphal instars as hosts for Encarsia formosa Gahan (Hymenoptera: Aphelinidae

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    Xin Liu

    2016-04-01

    Full Text Available Encarsia formosa Gahan (Hymenoptera: Aphelinidae is a solitary endoparasitoid that is commercially reared and released for augmentative biological control of whiteflies infesting greenhouse crops. In most areas in China, the invasive and destructive whitefly Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae biotype Q has replaced B. tabaci biotype B and has become dominant between the two. A better understanding of the suitability of different nymphal instars of B. tabaci biotypes Q and B as hosts for E. formosa is needed to improve the use of this parasitoid for biological control. Parasitism of the four nymphal instars of B. tabaci biotypes Q and B by the commercial strain of E. formosa mass reared on Trialeurodes vaporariorum (Westwood (Hemiptera: Aleyrodidae was assessed in the laboratory. The results indicated that E. formosa parasitized and successfully developed on all instars of both biotypes but performed best on the 3rd instar of B. tabaci biotype B and on the 2nd, 3rd, and 4th instars of B. tabaci biotype Q. The host-feeding rate of the adult parasitoid was generally higher on nymphal instars of B. tabaci biotype Q than on the corresponding nymphal instars of biotype B and was significantly higher on the 2nd and 3rd instars. For both whitefly biotypes, the parasitoid’s immature developmental period was the longest on the 1st instar, intermediate on the 2nd and 3rd instars, and the shortest on the 4th instar. The parasitoid emergence rate was significantly lower on the 1st instar than on the other three instars and did not significantly differ between B. tabaci biotype B and biotype Q. Offspring longevity was greater on the 3rd and 4th instars than on the 1st instar and did not significantly differ between the two B. tabaci biotypes. The results indicate that commercially-produced E. formosa can parasitize all instars of B. tabaci biotypes B and Q, making this parasitoid a promising tool for the management of the two biotypes of B

  1. How to Start with a Clean Crop: Biopesticide Dips Reduce Populations of Bemisia tabaci (Hemiptera: Aleyrodidae on Greenhouse Poinsettia Propagative Cuttings

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    Rosemarije Buitenhuis

    2016-09-01

    Full Text Available (1 Global movement of propagative plant material is a major pathway for introduction of Bemisia tabaci (Hemiptera: Aleyrodidae into poinsettia greenhouses. Starting a poinsettia crop with high pest numbers disrupts otherwise successful biological control programs and widespread resistance of B. tabaci against pesticides is limiting growers’ options to control this pest; (2 This study investigated the use of several biopesticides (mineral oil, insecticidal soap, Beauveria bassiana, Isaria fumosorosea, Steinernema feltiae and combinations of these products as immersion treatments (cutting dips to control B. tabaci on poinsettia cuttings. In addition, phytotoxicity risks of these treatments on poinsettia cuttings, and effects of treatment residues on mortality of commercial whitefly parasitoids (Eretmocerus eremicus and Encarsia formosa were determined; (3 Mineral oil (0.1% v/v and insecticidal soap (0.5% + B. bassiana (1.25 g/L were the most effective treatments; only 31% and 29%, respectively, of the treated B. tabaci survived on infested poinsettia cuttings and B. tabaci populations were lowest in these treatments after eight weeks. Phytotoxicity risks of these treatments were acceptable, and dip residues had little effect on survival of either parasitoid, and are considered highly compatible; (4 Use of poinsettia cutting dips will allow growers to knock-down B. tabaci populations to a point where they can be managed successfully thereafter with existing biocontrol strategies.

  2. Survey of Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae biotypes in Brazil using RAPD markers

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    L.H.C. Lima

    2000-12-01

    Full Text Available In 1991, the poinsettia strain, silverleaf whitefly or B biotype of Bemisia tabaci was detected in Brazil. This variant is a far more serious agricultural pest than the previously prevalent non-B (BR biotype. The correct identification of B. tabaci is problematic since it is highly polymorphic with extreme plasticity in key morphological characters that vary according to the host. RAPD-PCR was used to survey the B biotype and other biotypes of B. tabaci in Brazil. Whiteflies were collected from cultivated plants and weeds from 57 different localities and on 27 distinct crops. RAPD analyses using two selected 10-mer primers reliably identified the BR biotype and the B biotype of B. tabaci and also differentiated other whitefly species. The presence of the B biotype was confirmed in 20 Brazilian states. The BR and B biotypes of B. tabaci were found to coexist in the whitefly populations of three different localities: Jaboticabal, SP; Rondonópolis and Cuiabá, MT, and Goiânia, GO.Em 1991, um novo biótipo de Bemisia tabaci denominado de raça B, mosca branca da poinsétia ou mosca da folha prateada foi detectado no Brasil. Esta praga trouxe muitos prejuízos e danos à agricultura nacional, por ser mais agressiva do que a existente anteriormente, conhecida como B. tabaci ou B. tabaci biótipo BR (não B. A relação taxonômica entre B. tabaci e B. tabaci biótipo B não é clara e não existem evidências morfológicas consistentes que possam distinguir esses dois biótipos. RAPD-PCR tem sido utilizada para identificação de biótipos presentes nas populações, utilizando-se, como padrões de referência, adultos de Bemisia tabaci das raças A e B provenientes dos Estados Unidos. As coletas de mosca branca foram feitas em 27 culturas e plantas daninhas em 57 localidades do país. As populações foram então analisadas, observando-se que a população predominante em 20 estados brasileiros é de B. tabaci biótipo B. Os biótipos BR e B foram

  3. Effectiveness of thiamethoxam and imidacloprid seed treatments against Bemisia tabaci (Hemiptera: Aleyrodidae) on cotton.

    Science.gov (United States)

    Zhang, Liping; Greenberg, Shoil M; Zhang, Yongmei; Liu, Tong-Xian

    2011-02-01

    Bemisia tabaci (Gennadius) biotype B is one of the most important pests on cotton around the world. Laboratory, greenhouse and field experiments were conducted to determine the efficacy of thiamethoxam and imidacloprid seed treatments against B. tabaci on cotton. Under laboratory conditions, the two treatments caused whitefly adult mortality, reduced oviposition and increased mortality of nymphs at 10, 20, 30 and 40 days after germination (DAG). The longer the adults fed on plants from treated seeds, the higher the mortality. The two treatments did not have any effect on eggs. The efficacy of the treated seeds against B. tabaci gradually decreased from 10 to 40 DAG, being the lowest at 40 DAG. In laboratory experiments, the efficacies between the two treatments were similar. In greenhouse experiments, the two treatments were equally effective with lower numbers of whiteflies than untreated controls. With both treatments the concentrations of the active ingredient were gradually reduced with aging of the plants and from the bottom to the top leaves of the plants. Numbers of live whiteflies were well correlated with the dosage of active ingredients. Under field conditions, the seeds treated with both insecticides exhibited similar efficacy against B. tabaci for up to ~2 months. Cotton seeds treated with imidacloprid and thiamethoxam were effective against B. tabaci for up to 45 days under laboratory and greenhouse conditions, and up to ~2 months under field conditions. Use of imidacloprid- and thiamethoxam-treated seeds can be an important alternative for management of whiteflies on cotton. Copyright © 2010 Society of Chemical Industry.

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

    Science.gov (United States)

    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.

  5. Aphid-induced Defences in Chilli Affect Preferences of the Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Saad, Khalid A; Mohamad Roff, M N; Hallett, Rebecca H; Idris, A B

    2015-09-03

    The sweetpotato whitefly (WF), Bemisia tabaci, is a major pest that damages a wide range of vegetable crops in Malaysia. WF infestation is influenced by a variety of factors, including previous infestation of the host plant by other insect pests. This study investigated the effects of previous infestation of host chilli plants by the green peach aphid (Myzus persicae) on the olfactory behavioural response of B. tabaci, using free-choice bioassay with a Y-tube olfactometer. We analysed volatile organic compounds (VOCs) emitted by non-infested and M. persicae-infested chilli plants using solid-phase microextraction and gas chromatography-mass spectrometry. Our results showed that female WFs preferred non-infested to pre-infested plants. Collection and analysis of volatile compounds emitted by infested plants confirmed that there were significant increases in the production of monoterpenes (cymene; 1,8-cineole), sesquiterpenes (β-cadinene, α-copaene), and methyl salicylate (MeSA) compared to non-infested plants. Our results suggest that host plant infestation by aphids may induce production of secondary metabolites that deter B. tabaci from settling on its host plants. These results provide important information for understanding WF host selection and dispersal among crops, and also for manipulating WF behaviour to improve IPM in chilli.

  6. Dinâmica Populacional de Mosca-Branca Bemisia tabaci (Genn. Biótipo B (Hemiptera: Aleyrodidae em Feijoeiro

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    Anderson Silva

    2014-04-01

    Abstract. This study aimed to evaluate the influence of abiotic factors on the population dynamics of the whitefly Bemisia tabaci (Genn., (Hemiptera: Aleyrodidae in three sowing seasons on bean plants (Phaseolus vulgaris L.. The assays were set up from June 2010 to April 2012 and conducted in the Departamento de Fitossanidade at FCAV/UNESP – Campus of Jaboticabal, SP. The studies of the population dynamics of B. tabaci biotype B were performed weekly through infestation assessments of eggs, nymphs and adults of the whitefly on 18 samplings, six for each sowing season: “winter”, “water” and “dry”, in addition to the influence of the abiotic factors weekly temperature and relative humidity (minimum, average and maximum and accumulated rainfall. These variables were correlated to the total number of eggs, nymphs and adults of the whitefly through Pearson’s linear correlation analysis. Among the obtained results, the population peaks of B. tabaci biotype B occurred at the “water” season, followed by “winter” and “dry” seasons, and the abiotic factors temperature and relative humidity influenced negatively the population dynamics of the whitefly.

  7. Feeding Experience of Bemisia tabaci (Hemiptera: Aleyrodidae) Affects Their Performance on Different Host Plants

    Science.gov (United States)

    Shah, M. Mostafizur Rahman; Liu, Tong-Xian

    2013-01-01

    The sweetpotato whitefly, Bemisia tabaci biotype B is extremely polyphagous with >600 species of host plants. We hypothesized that previous experience of the whitefly on a given host plant affects their host selection and performance on the plants without previous experience. We investigated the host selection for feeding and oviposition of adults and development and survival of immatures of three host-plant-experienced populations of B. tabaci, namely Bemisia-eggplant, Bemisia-tomato and Bemisia-cucumber, on their experienced host plant and each of the three other plant species (eggplant, tomato, cucumber and pepper) without previous experience. We found that the influence of previous experience of the whiteflies varied among the populations. All populations refused pepper for feeding and oviposition, whereas the Bemisia-cucumber and the Bemisia-eggplant strongly preferred cucumber. Bemisia-tomato did not show strong preference to any of the three host palnts. Development time from egg to adult eclosion varied among the populations, being shortest on eggplant, longest on pepper, and intermediate on tomato and cucumber except for the Bemisia-cucumber developed similarly on tomato and pepper. The survivorship from egg to adult eclosion of all populations was highest on eggplant (80-98%), lowest on pepper (0-20%), and intermediate on tomato and cucumber. In conclusion, the effects of previous experience of whiteflies on host selection for feeding and oviposition, development, and survivorship varied depending on host plants, and host plants play a stronger role than previous experience. Preference of feeding and oviposition by adults may not accurately reflect host suitability of immatures. These results provided important information for understanding whitefly population dynamics and dispersal among different crop systems. PMID:24146985

  8. 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.

  9. 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

  10. Leaf Morphological Characters Can Be a Factor for Intra-Varietal Preference of Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) among Eggplant Varieties.

    Science.gov (United States)

    Hasanuzzaman, Abu Tayeb Mohammad; Islam, Md Nazrul; Zhang, Yi; Zhang, Chen-Yang; Liu, Tong-Xian

    2016-01-01

    The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) MEAM1, is considered a serious pest of horticultural and many other crops. While eggplant (Solanum melongena) is one of the most favored host plants, the whiteflies exhibit preferences among different varieties. We hypothesized that certain morphological leaf characteristics of different varieties, like leaf trichome density, trichome length, leaf lamina thickness and leaf color, may affect whitefly landing, feeding and oviposition. In this study, we investigated the variation in leaf morphological characters among selected eggplant varieties and evaluated the effect of these leaf characteristics in rendering eggplant varieties either susceptible or resistant to B. tabaci. We evaluated eight eggplant varieties in choice feeding tests, and we found that the varieties JinSheng Zilongchangqie (JSZ) and H149 were the highly preferred varieties with the highest numbers of whitefly adults and eggs. Significantly lower numbers of whitefly adult eggs were found on the resistant variety Tuo Lu Bamu (TLB). The varieties JinGuangbo Luqie (JGL), JinGuangbo Ziquanqie (JGZ), DaYang Ziguanqie (DYZ), QinXing Ziguanqie (QXZ), and QinXing Niuxinqie (QXN) were moderately favored by B. tabaci. Leaf trichome density, trichome length and leaf lamina thickness were positively correlated with numbers of whitefly adults and eggs. B. tabaci was less attracted to the leaves that reflect long and middle wavelength light (higher R and G values) than to the bright green leaves (medium G value), but the short wavelength light (higher B value) had no significant effect on whitefly preference. The degree of hue had a positive effect, and saturation and brightness had a negative effect on whitefly attraction.

  11. 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)

  12. Transcriptome analysis of host-associated differentiation in Bemisia tabaci (Hemiptera: Aleyrodidae

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    Wen eXie

    2014-12-01

    Full Text Available Host-associated differentiation is one of the driving forces behind the diversification of phytophagous insects. In this study, host induced transcriptomic differences were investigated in the sweetpotato whitefly Bemisia tabaci, an invasive agricultural pest worldwide. Comparative transcriptomic analyses using coding sequence (CDS, 5’ and 3’ untranslated regions (UTR showed that sequence divergences between the original host plant, cabbage, and the derived hosts, including cotton, cucumber and tomato, were 0.11%-0.14%, 0.19%-0.26% and 0.15%-0.21%, respectively. In comparison to the derived hosts, 418 female and 303 male transcripts, respectively, were up-regulated in the original cabbage strain. Among them, 17 transcripts were consistently up-regulated in both female and male whiteflies originated from the cabbage host. Specifically, two ESTs annotated as Cathepsin B or Cathepsin B-like genes were significantly up-regulated in the original cabbage strain, representing a transcriptomic response to the dietary challenges imposed by the host shifting. Results from our transcriptome analysis, in conjunction with previous reports documenting the minor changes in their reproductive capacity, insecticide susceptibility, symbiotic composition and feeding behavior, suggest that the impact of host-associated differentiation in whiteflies is limited. Furthermore, it is unlikely the major factor contributing to their rapid range expansion/invasiveness.

  13. 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.

  14. Age Stage Two-Sex Life Table Reveals Sublethal Effects of Some Herbal and Chemical Insecticides on Adults of Bemisia tabaci (Hem.: Aleyrodidae

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    Fatemeh Jafarbeigi

    2014-01-01

    Full Text Available The sweetpotato whitefly, Bemisia tabaci (Genn. (Hem.: Aleyrodidae, is an important pest of agriculture in subtropical and tropical areas. In this study, we used the age-stage two-sex life table to evaluate the sublethal effects of the herbal extracts taken from Fumaria parviflora Lam. (Fumariaceae, Teucrium polium L. (Lamiaceae, Calotropis procera (Willd. R. Br. (Asclepiadaceae, and Thymus vulgaris L. (Lamiaceae as well as the two commercial synthetic insecticides, pymetrozin and neemarin. The whiteflies were exposed to each insecticide using leaf-dip method. Analysis of life table parameters revealed significant differences (P≤0.05 in the net reproductive rate (R0, NRR, intrinsic rate of increase (rm, and finite rate of increase (λ among different insecticides. The lowest values of the three population parameters, R0, r, and λ, were observed on whiteflies treated with pymetrozin (2.455, 0.036, and 1.036, T. polium (2.828, 0.044, and 1.045, and neemarin (2.998, 0.046, and 1.047, respectively. Results of this study highlights the satisfactory insecticidal effects of the extract taken from T. polium on B. tabaci, which is comparable to the two commonly used synthetic insecticides.

  15. DNA Barcoding of Bemisia tabaci Complex (Hemiptera: Aleyrodidae) Reveals Southerly Expansion of the Dominant Whitefly Species on Cotton in Pakistan

    OpenAIRE

    Ashfaq, Muhammad; Hebert, Paul D. N.; Mirza, M. Sajjad; Khan, Arif M.; Mansoor, Shahid; Shah, Ghulam S.; Zafar, Yusuf

    2014-01-01

    Background Although whiteflies (Bemisia tabaci complex) are an important pest of cotton in Pakistan, its taxonomic diversity is poorly understood. As DNA barcoding is an effective tool for resolving species complexes and analyzing species distributions, we used this approach to analyze genetic diversity in the B. tabaci complex and map the distribution of B. tabaci lineages in cotton growing areas of Pakistan. Methods/Principal Findings Sequence diversity in the DNA barcode region (mtCOI-5′) ...

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

    Science.gov (United States)

    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.

  17. Phylogeographical structure in mitochondrial DNA of whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) in southern India and Southeast Asia.

    Science.gov (United States)

    Ram Kumar, Nikhil; Chang, Jian-Cheng; Narayanan, Manikanda Boopathi; Ramasamy, Srinivasan

    2017-09-01

    South and Southeast Asia endure high vegetable production losses due to begomovirus diseases mainly transmitted by the insect vector, whitefly (Bemisia tabaci). Control over the spread of virus infection can be achieved through a better understanding of genetic diversity among B. tabaci. A total of 64 populations of B. tabaci collected from Tamil Nadu (India), Vietnam, Thailand, and Indonesia were investigated based on mitochondrial cytochrome c oxidase I (coxI) sequences. Populations from Tamil Nadu are distributed into three clades (Asia I, Asia II 7, and Asia II 8), whereas Indonesian populations settle along with Asia I population of India in the phylogenetic tree. Vietnam populations align with the Middle East-Asia Minor 1 (MEAM1) clade, and interestingly MEAM1 invades northern Vietnam quite recently. Samples from Thailand made a unique clade between the outgroup and the remaining B. tabaci, representing the possibility of a new subspecies. AMOVA analysis among populations from various districts in Tamil Nadu exhibits significant differences, which represent each district's individuality. This study proves that the use of coxI as a marker for molecular identification of B. tabaci can provide a better estimate of diversity. We provide important clues for developing insight into the genetic structure of B. tabaci, and suggest strategies for control.

  18. DNA barcoding of Bemisia tabaci complex (Hemiptera: Aleyrodidae) reveals southerly expansion of the dominant whitefly species on cotton in Pakistan.

    Science.gov (United States)

    Ashfaq, Muhammad; Hebert, Paul D N; Mirza, M Sajjad; Khan, Arif M; Mansoor, Shahid; Shah, Ghulam S; Zafar, Yusuf

    2014-01-01

    Although whiteflies (Bemisia tabaci complex) are an important pest of cotton in Pakistan, its taxonomic diversity is poorly understood. As DNA barcoding is an effective tool for resolving species complexes and analyzing species distributions, we used this approach to analyze genetic diversity in the B. tabaci complex and map the distribution of B. tabaci lineages in cotton growing areas of Pakistan. Sequence diversity in the DNA barcode region (mtCOI-5') was examined in 593 whiteflies from Pakistan to determine the number of whitefly species and their distributions in the cotton-growing areas of Punjab and Sindh provinces. These new records were integrated with another 173 barcode sequences for B. tabaci, most from India, to better understand regional whitefly diversity. The Barcode Index Number (BIN) System assigned the 766 sequences to 15 BINs, including nine from Pakistan. Representative specimens of each Pakistan BIN were analyzed for mtCOI-3' to allow their assignment to one of the putative species in the B. tabaci complex recognized on the basis of sequence variation in this gene region. This analysis revealed the presence of Asia II 1, Middle East-Asia Minor 1, Asia 1, Asia II 5, Asia II 7, and a new lineage "Pakistan". The first two taxa were found in both Punjab and Sindh, but Asia 1 was only detected in Sindh, while Asia II 5, Asia II 7 and "Pakistan" were only present in Punjab. The haplotype networks showed that most haplotypes of Asia II 1, a species implicated in transmission of the cotton leaf curl virus, occurred in both India and Pakistan. DNA barcodes successfully discriminated cryptic species in B. tabaci complex. The dominant haplotypes in the B. tabaci complex were shared by India and Pakistan. Asia II 1 was previously restricted to Punjab, but is now the dominant lineage in southern Sindh; its southward spread may have serious implications for cotton plantations in this region.

  19. DNA barcoding of Bemisia tabaci complex (Hemiptera: Aleyrodidae reveals southerly expansion of the dominant whitefly species on cotton in Pakistan.

    Directory of Open Access Journals (Sweden)

    Muhammad Ashfaq

    Full Text Available Although whiteflies (Bemisia tabaci complex are an important pest of cotton in Pakistan, its taxonomic diversity is poorly understood. As DNA barcoding is an effective tool for resolving species complexes and analyzing species distributions, we used this approach to analyze genetic diversity in the B. tabaci complex and map the distribution of B. tabaci lineages in cotton growing areas of Pakistan.Sequence diversity in the DNA barcode region (mtCOI-5' was examined in 593 whiteflies from Pakistan to determine the number of whitefly species and their distributions in the cotton-growing areas of Punjab and Sindh provinces. These new records were integrated with another 173 barcode sequences for B. tabaci, most from India, to better understand regional whitefly diversity. The Barcode Index Number (BIN System assigned the 766 sequences to 15 BINs, including nine from Pakistan. Representative specimens of each Pakistan BIN were analyzed for mtCOI-3' to allow their assignment to one of the putative species in the B. tabaci complex recognized on the basis of sequence variation in this gene region. This analysis revealed the presence of Asia II 1, Middle East-Asia Minor 1, Asia 1, Asia II 5, Asia II 7, and a new lineage "Pakistan". The first two taxa were found in both Punjab and Sindh, but Asia 1 was only detected in Sindh, while Asia II 5, Asia II 7 and "Pakistan" were only present in Punjab. The haplotype networks showed that most haplotypes of Asia II 1, a species implicated in transmission of the cotton leaf curl virus, occurred in both India and Pakistan.DNA barcodes successfully discriminated cryptic species in B. tabaci complex. The dominant haplotypes in the B. tabaci complex were shared by India and Pakistan. Asia II 1 was previously restricted to Punjab, but is now the dominant lineage in southern Sindh; its southward spread may have serious implications for cotton plantations in this region.

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

    Science.gov (United States)

    Nunes, Endson S; Brown, Judith K; Moreira, Adriana G; Watson, Gillian; Lourenção, André L; Piedade, Sônia M S; Rezende, Jorge A M; Vieira, Maria L C

    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.

  1. 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)

  2. Reference gene selection for qRT-PCR analysis in the sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Li, Rumei; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Yang, Nina; Yang, Xin; Pan, Huipeng; Zhou, Xiaomao; Bai, Lianyang; Xu, Baoyun; Zhou, Xuguo; Zhang, Youjun

    2013-01-01

    Accurate evaluation of gene expression requires normalization relative to the expression of reliable reference genes. Expression levels of "classical" reference genes can differ, however, across experimental conditions. Although quantitative real-time PCR (qRT-PCR) has been used extensively to decipher gene function in the sweetpotato whitefly Bemisia tabaci, a world-wide pest in many agricultural systems, the stability of its reference genes has rarely been validated. In this study, 15 candidate reference genes from B. tabaci were evaluated using two Excel-based algorithms geNorm and Normfinder under a diverse set of biotic and abiotic conditions. At least two reference genes were selected to normalize gene expressions in B. tabaci under experimental conditions. Specifically, for biotic conditions including host plant, acquisition of a plant virus, developmental stage, tissue (body region of the adult), and whitefly biotype, ribosomal protein L29 was the most stable reference gene. In contrast, the expression of elongation factor 1 alpha, peptidylprolyl isomerase A, NADH dehydrogenase, succinate dehydrogenase complex subunit A and heat shock protein 40 were consistently stable across various abiotic conditions including photoperiod, temperature, and insecticide susceptibility. Our finding is the first step toward establishing a standardized quantitative real-time PCR procedure following the MIQE (Minimum Information for publication of Quantitative real time PCR Experiments) guideline in an agriculturally important insect pest, and provides a solid foundation for future RNA interference based functional study in B. tabaci.

  3. Identification, characterization and expression of a defensin-like antifungal peptide from the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Wang, Z-Z; Shi, M; Ye, X-Q; Chen, M-Y; Chen, X-X

    2013-06-01

    Defensins are a class of small and diverse cysteine-rich proteins which have broad-spectrum antimicrobial activities. We identified and characterized a full-length cDNA encoding a putative defensin-like peptide from the whitefly Bemisia tabaci by RACE and quantitative real-time (qRT)-PCR. The full-length cDNA, named Btdef, was 388 bp long and contained an open reading frame of 228 bp. The putative mature Btdef had 46 amino acids with a molecular weight of 5.06 kDa. The deduced amino acid sequence showed significant homology with insect defensins from Heliothis virescens (76%) and Galleria mellonella (75%). The predicted mature form of Btdef was expressed as a recombinant peptide in Escherichia coli. Antimicrobial assays of the purified product indicated that Btdef was most active against fungi. qRT-PCR analyses indicated that Btdef mRNA was constitutively expressed in different tissues of B. tabaci, including fat body, midgut, ovaries and salivary gland, and was induced by fungal infection. Btdef mRNA expression was also significantly altered after feeding on different host plants, indicating that diet affects immune defences in B. tabaci. These results describe for the first time the basic properties of a defensin-like peptide from B. tabaci that probably plays an important role in the immune response against pathogens. © 2013 Royal Entomological Society.

  4. Presence of Bemisia tabaci (Hemiptera: Aleyrodidae and Begomovirus, associated with tomato crops Solanum lycopersicum L. in Cundinamarca

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    Olga Y Martínez B

    2012-09-01

    Full Text Available This study was undertaken to determine the presence and distribution of species of whiteflies in Cundinamarca, in the tomato, located in nine municipalities; for this purpose, insect samples were collected from the lower third of leaflets to identify nymphs of the fourth instar and from the upper third to identify adults with molecular markers RAPD-PCR (primer OPA 04; we also analyzed the presence of Begomoviruses (Family Geminiviridae in tomato plants with nucleic acid hybridization in the nylon membrane. The results indicated the presence of Trialeurodes vaporariorum (Westwood as the predominant species at 40.9%, Bemisia tabaci biotype B at 4.5% and coexistence at 54.6%. B. tabaci biotype B had a wide distribution with respect to other studies, between 383 to 1,857 m a.s.l. The presence of Begomovirus was related to its vector B. tabaci biotype B in 4 out of 15 tomato-producing provinces of the department. The insecticides used for control are organophosphates (41.18%, neonicotenoids (29.41%, carbamates (17.65% and pyrethroids (11.76%. We discuss the disturbing and rapid spread of B. tabaci biotype B in Cundinamarca

  5. Reference gene selection for qRT-PCR analysis in the sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae.

    Directory of Open Access Journals (Sweden)

    Rumei Li

    Full Text Available Accurate evaluation of gene expression requires normalization relative to the expression of reliable reference genes. Expression levels of "classical" reference genes can differ, however, across experimental conditions. Although quantitative real-time PCR (qRT-PCR has been used extensively to decipher gene function in the sweetpotato whitefly Bemisia tabaci, a world-wide pest in many agricultural systems, the stability of its reference genes has rarely been validated.In this study, 15 candidate reference genes from B. tabaci were evaluated using two Excel-based algorithms geNorm and Normfinder under a diverse set of biotic and abiotic conditions. At least two reference genes were selected to normalize gene expressions in B. tabaci under experimental conditions. Specifically, for biotic conditions including host plant, acquisition of a plant virus, developmental stage, tissue (body region of the adult, and whitefly biotype, ribosomal protein L29 was the most stable reference gene. In contrast, the expression of elongation factor 1 alpha, peptidylprolyl isomerase A, NADH dehydrogenase, succinate dehydrogenase complex subunit A and heat shock protein 40 were consistently stable across various abiotic conditions including photoperiod, temperature, and insecticide susceptibility.Our finding is the first step toward establishing a standardized quantitative real-time PCR procedure following the MIQE (Minimum Information for publication of Quantitative real time PCR Experiments guideline in an agriculturally important insect pest, and provides a solid foundation for future RNA interference based functional study in B. tabaci.

  6. Glutathione S-transferases are involved in thiamethoxam resistance in the field whitefly Bemisia tabaci Q (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Yang, Xin; He, Chao; Xie, Wen; Liu, Yating; Xia, Jixing; Yang, Zezong; Guo, Litao; Wen, Yanan; Wang, Shaoli; Wu, Qingjun; Yang, Fengshan; Zhou, Xiaomao; Zhang, Youjun

    2016-11-01

    The whitefly, Bemisia tabaci, has developed a high level of resistance to thiamethoxam, a second generation neonicotinoid insecticide that has been widely used to control this pest. In this study, we assessed the level of cross-resistance, the activities of detoxifying enzymes, and the expression profiles of 23 glutathione S-transferase (GST) genes in a thiamethoxam-resistant ant and -susceptible strain of Bemisia tabaci Q. The thiamethoxam-resistant strain showed a moderate level of cross-resistance to another nicotinoid insecticide imidacloprid, a low level of cross-resistance to acetamiprid and nitenpyram, and no significant cross-resistance to abamectin and bifenthrin. Among detoxifying enzymes, only GSTs had significantly higher activity in the resistant strain than in the susceptible strain. Seven of 23 GST genes were over-expressed in the resistant strain relative to the susceptible strain. Using the technology of RNA interference to knockdown a GST gene (GST14), the results showed that silencing GST14 increased the mortality of whiteflies to thiamethoxam in Bemisia tabaci. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Relative influence of plant quality and natural enemies on the seasonal dynamics of Bemisia tabaci (Hemiptera: Aleyrodidae) in cotton.

    Science.gov (United States)

    Asiimwe, Peter; Naranjo, Steven E; Ellsworth, Peter C

    2013-06-01

    The abundance and distribution of insect herbivores is determined by, among other things, plant quality and natural enemies. These two factors vary temporally and spatially, subsequently affecting seasonal population dynamics. The relative influence of plant quality and natural enemies on the seasonal dynamics of Bemisia tabaci (Gennadius) was investigated in a 3-yr field study in cotton. Plant quality was manipulated through varying irrigation regimes: irrigations done at 20, 40, and 60% soil water depletions; and natural enemy densities were manipulated using broad spectrum insecticide applications that reduced their densities compared with unsprayed controls. In each year, densities of B. tabaci eggs, large nymphs and adults were consistently higher when natural enemy densities were reduced compared with when they were left unaltered, regardless of irrigation regime. In contrast, effects of plant quality on densities of all whitefly stages were weak and inconsistent. In addition, natural enemy densities and predator:prey ratios also were not generally affected by plant quality. Interactions between natural enemies and plant quality on whitefly dynamics were rare. In general, whitefly densities were elevated two-thirds of the time and increased two- to sixfold when natural enemy densities were reduced compared with plant quality effects which influenced whitefly densities about one-third of the time and were expressed inconsistently over the years. This indicates that natural enemies exert a comparatively greater influence on seasonal dynamics of B. tabaci in cotton than plant quality, as manipulated by differential irrigation.

  8. Biology of Bemisia tabaci (Genn. B biotype (Hemiptera, Aleyrodidae on tomato genotypes Biologia de Bemisia tabaci (Genn. Biótipo B (Hemiptera, Aleyrodidae em genótipos de tomateiro

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    Maria Auxiliadora de Godoy Oriani

    2011-02-01

    Full Text Available Brazil is one of the main tomato (Solanum lycopersicum producers worldwide. Nevertheless, considerable part of the production is lost due to Bemisia tabaci (Genn. B biotype attacks. Resistant plants can be an important method for controlling this pest in an integrated pest management. Tests for evaluating some biological aspects of B. tabaci were carried out on 18 tomato genotypes, in controlled laboratory greenhouse conditions. Thirty-day-old plants placed in plastic cages were infested with 20 whitefly pairs each, for 24 h. The development of at least 30 eggs in three leaflets per plant (repetition was observed until adult emergence. The development period of insects grown in LA1335, PI365928 and LA722 genotypes took three days longer when compared to the ones grown in PI134418 (20.3 days. The highest mortality rate of whitefly nymphs occurred in PI365928, LA1335 and LA722 genotypes (63.8, 54.5 and 53.3%, respectively, and the smallest ones in IAC294 and IAC68F-22-2 genotypes (4.9 e 6.2%, respectively. LA1335, PI365928 and LA722 genotypes presented moderate feeding nonpreference and/or antibiosis-based resistance to B. tabaci B biotype.O Brasil é um dos maiores produtores mundiais de tomate (Solanum lycopersicum, porém grande parte da produção é perdida devido ao ataque de Bemisia tabaci (Genn. biótipo B. Entre as táticas de controle dessa praga num manejo integrado de pragas, pode-se relacionar a resistência de plantas. Ensaios para avaliar alguns aspectos biológicos de B. tabaci foram realizados com 18 genótipos de tomateiro, em condições controladas de laboratório (casa de vegetação. Plantas com 30 dias de idade foram colocadas em gaiolas plásticas e infestadas com 20 casais de moscas-brancas cada, durante 24h. Acompanhou-se então o desenvolvimento de pelo menos 30 ovos em três folíolos por planta (repetição até a emergência dos insetos. Os insetos criados nos genótipos LA1335, PI365928 e LA722 apresentaram

  9. 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.

  10. 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.

  11. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  12. 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

  13. Occurrence of Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae parasitizing Bemisia tabaci (Genn. biotype B (Hemiptera: Aleyrodidae in Brazil

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    André Luiz Lourenção

    2014-06-01

    Full Text Available The parasitism of Bemisia tabaci (Genn. biotype B nymphs on cotton plants was observed during a research on resistance of cotton genotypes to this whitefly. The experiment was set in a greenhouse at the Experimental Station of the Instituto Agronômico (IAC, in Campinas, São Paulo State, Brazil. Samples of the parasitized nymphs were collected and maintained in laboratory to monitor the parasitism and obtain the adult parasitoids. A total of 129 adult parasitoids were obtained, including one Encarsia inaron (Walker, 13 En. lutea (Masi, and 115 Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae. This is the first report of Er. mundus in Brazil.

  14. 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

  15. 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

    Directory of Open Access Journals (Sweden)

    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

  16. 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

  17. Flupyradifurone effectively manages whitefly Bemisia tabaci MED (Hemiptera: Aleyrodidae) and tomato yellow leaf curl virus in tomato.

    Science.gov (United States)

    Roditakis, Emmanouil; Stavrakaki, Marianna; Grispou, Maria; Achimastou, Aikaterini; Van Waetermeulen, Xavier; Nauen, Ralf; Tsagkarakou, Anastasia

    2017-08-01

    The cotton whitefly Bemisia tabaci (Gennadius) is among the most important pests of numerous crops and a vector of more than 100 plant viruses, causing significant crop losses worldwide. Managing this pest as well as inhibiting the transmission of major viruses such as tomato yellow leaf curl virus (TYLCV) are of utmost importance for sustainable yields. The efficacy against both whitefly and virus transmission of the novel systemic butenolide insecticide flupyradifurone was investigated in this study. The inhibition of TYLCV transmission by flupyradifurone was compared to that by thiamethoxam, a neonicotinoid insecticide reported to inhibit virus transmission. The experiment was performed under high virus pressure conditions (10 viruliferous insects per plant for 48 h) using a fully characterized field strain of B. tabaci. The insecticides were foliarly applied at recommended label rates under greenhouse conditions. Flupyradifurone suppressed virus transmission by 85% while levels of suppression after thiamethoxam treatments were just 25% and significantly lower. In untreated control plots, 100% of plants were infected by TYLCV. The observed difference in the potential to suppress virus transmission is linked to a strong knockdown effect as well as prolonged feeding inhibition in flupyradifurone treatments. Flupyradifurone is shown to be an extremely useful, fast-acting, new chemical tool in integrated crop management offering simultaneous control of whiteflies and strong suppression of viral infections via its rapid knockdown action and good residual activity. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  18. 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.

  19. Direct and Indirect Impacts of Infestation of Tomato Plant by Myzus persicae (Hemiptera: Aphididae) on Bemisia tabaci (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    Tan, Xiao-Ling; Wang, Su; Ridsdill-Smith, James; Liu, Tong-Xian

    2014-01-01

    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. PMID:24710393

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

    Science.gov (United States)

    Tan, Xiao-Ling; Wang, Su; Ridsdill-Smith, James; Liu, Tong-Xian

    2014-01-01

    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.

  1. 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)

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Asymmetric adaptation to indolic and aliphatic glucosinolates in the B and Q sibling species of Bemisia tabaci (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Elbaz, M; Halon, E; Malka, O; Malitsky, S; Blum, E; Aharoni, A; Morin, S

    2012-09-01

    The role glucosinolates play in defending plants against phloem feeders such as aphids and whiteflies is currently not clear as these herbivores may avoid bringing glucosinolates from the phloem sap into contact with myrosinase enzymes. Here, we investigated the effects of high levels of aliphatic and indolic glucosinolates on life history traits and detoxification gene expression in two sibling species, B and Q, of the whitefly Bemisia tabaci. High levels of aliphatic glucosinolates decreased the average oviposition rate of both species and reduced the survival and developmental rate of Q nymphs. High levels of indolic glucosinolates decreased the oviposition rate and survival of nymphal stages of the B species and the developmental rate of both species. Molecular analyses revealed two major asymmetries between the B and Q species. First, specific GST genes (BtGST1 and BtGST2) were significantly induced during exposure to indolic glucosinolates only in Q. This may reflect the genes putative involvement in indolic glucosinolates detoxification and explain the species' good performance on plants accumulating indolic glucosinolates. Second, the constitutive expression of eight of the 10 detoxification genes analysed was higher in the Q species than in the B species. Interestingly, four of these genes were induced in B in response to high levels of glucosinolates. It seems, therefore, that the B and Q species differ in their 'optimal defence strategy'. B utilizes inducible defences that are profitable if the probability of experiencing the stress is small and its severity is low, while Q invests significant resources in being always 'ready' for a challenge. © 2012 Blackwell Publishing Ltd.

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

    Science.gov (United States)

    Yang, Zezhong; Xia, Jixing; Pan, Huipeng; Gong, Cheng; Xie, Wen; Guo, Zhaojiang; Zheng, Huixin; Yang, Xin; Yang, Fengshan; Wu, Qingjun; Wang, Shaoli; Zhang, Youjun

    2017-01-01

    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 .

  5. 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...

  6. Use of fluorescence, a novel technique to determine reduction in Bemisia tabaci (Hemiptera: Aleyrodidae) nymph feeding when exposed to Benevia and other insecticides.

    Science.gov (United States)

    Cameron, Rachel; Lang, Edward B; Annan, I Billy; Portillo, Hector E; Alvarez, Juan M

    2013-04-01

    The sweet potato whitefly, Bemisia tabaci (Gennadius), is an economically important pest in the United States and other countries. Growers in many places rely on the use of insecticides to reduce populations of B. tabaci. However, insecticides may take a few days to cause B. tabaci mortality and some do not reduce feeding before death. Earlier reduction of feeding of whiteflies would decrease the physiological effects on plants, reduce the production of sooty mold and potentially reduce the transmission of viruses. Measuring the reduction in feeding after the exposure of B. tabaci to an insecticide has proven difficult. This series of laboratory experiments demonstrate the usefulness of fluorescence in determining B. tabaci feeding cessation. Fluorescein sodium salt is systemically transported in the xylem from the roots to the plant leaves and absorbed by B. tabaci nymphs feeding on these plants. Nymphs start fluorescing shortly after the cotton plant root system is submerged in the fluorescein sodium salt. Using this novel technique, the effect of three insecticides with different modes of action, cyantraniliprole, imidacloprid, and spirotetramat on B. tabaci was evaluated and compared to determine reduction in feeding. Results indicate that B. tabaci nymphs feeding on a plant treated with Benevia have a significant reduction of feeding when compared with nymphs feeding on plants treated with imidacloprid or spirotetramat. Both Benevia and spirotetramat caused significant nymphal mortality by 48 h after exposure. This novel technique will be useful to demonstrate the feeding cessation or reduction in feeding produced by different insecticides in several sucking insect groups.

  7. 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

    Directory of Open Access Journals (Sweden)

    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

  8. 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

    and forcing some farmers to abandon the cultivation of the crop. The severe CMD pandemic is mainly characterized by high severity and incidence of the disease dominated by whitefly-borne infection and super-abundant populations of B. tabaci. All Bemisia tabaci individuals harbour a primary bacterial symbiont...... with the pandemic; (ii) to establish the prevalence of endosymbionts among B. tabaci populations on cassava and nearby plants, to assess if there is a unique  endosymbiont that is associated with super-abundant whitefly populations and to provide baseline information on endosymbionts of whiteflies for Tanzania......; and (iii) to investigate the population structure of and the possibilities of gene flow between B. tabaci populations found in CMD pandemic affected and not yet affected parts of Tanzania. Hence, several field surveys were conducted in CMD pandemic-affected and unaffected areas in Tanzania and whiteflies...

  9. Deep Sequencing-Based Transcriptome Analysis Reveals the Regulatory Mechanism of Bemisia tabaci (Hemiptera: Aleyrodidae Nymph Parasitized by Encarsia sophia (Hymenoptera: Aphelinidae.

    Directory of Open Access Journals (Sweden)

    Yingying Wang

    Full Text Available The whitefly Bemisia tabaci is a genetically diverse complex with multiple cryptic species, and some are the most destructive invasive pests of many ornamentals and crops worldwide. Encarsia sophia is an autoparasitoid wasp that demonstrated high efficiency as bio-control agent of whiteflies. However, the immune mechanism of B. tabaci parasitization by E. sophia is unknown. In order to investigate immune response of B. tabaci to E. Sophia parasitization, the transcriptome of E. sophia parasitized B. tabaci nymph was sequenced by Illumina sequencing. De novo assembly generated 393,063 unigenes with average length of 616 bp, in which 46,406 unigenes (15.8% of all unigenes were successfully mapped. Parasitization by E. sophia had significant effects on the transcriptome profile of B. tabaci nymph. A total of 1482 genes were significantly differentially expressed, of which 852 genes were up-regulated and 630 genes were down-regulated. These genes were mainly involved in immune response, development, metabolism and host signaling pathways. At least 52 genes were found to be involved in the host immune response, 33 genes were involved in the development process, and 29 genes were involved in host metabolism. Taken together, the assembled and annotated transcriptome sequences provided a valuable genomic resource for further understanding the molecular mechanism of immune response of B. tabaci parasitization by E. sophia.

  10. Comparative transmission of Bhendi yellow vein mosaic virus by two cryptic species of the whitefly,Bemisia tabaci(Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Venkataravanappa, V; Kodandaram, M H; Lakshminarayana Reddy, C N; Shankarappa, K S; Krishna Reddy, M

    2017-10-01

    The leaf sample from okra plants showing prominent yellow vein mosaic symptoms and healthy plant without any virus symptoms were collected from farmer's field. The presence of begomovirus in the infected sample was confirmed by polymerase chain reaction (PCR) and the amplicons were cloned and sequenced. The genome analysis showed that the isolate in the present study had 99% nucleotide identity with Bhendi yellow vein mosaic virus (BYVMV) revealing it as BYVMV variant. The genetic species of Bemisia tabaci collected from fields were identified as Asia-1 and MEAM-1 genetic species based on silver leaf assay, sequence characterized amplified region marker, and mtCOI gene sequence. The comparative virus-vector relationship of both genetic species of B. tabaci indicates a minimum of two and three B. tabaci in MEAM-1 and Asia-1 genetic species, respectively, per plant were required to transmit the disease. The minimum acquisition access period and inoculation access period of 15 (MEAM-1) and 20 min (Asia-1) were required to transmit the YVMD; it was further confirmed by nucleic acid hybridization using coat protein gene-specific probe of BYVMV. With respect to the sex, the female B. tabaci were more efficient in transmitting the disease as compared to male ones in both the genetic species of B. tabaci . The MEAM-1 to transmit the BYVMV more efficiently than Asia-1 genetic species of B. tabaci.

  11. Surtos populacionais de Bemisia tabaci no estado de São Paulo Outbreaks of Bemisia tabaci in the São Paulo State, Brazil

    Directory of Open Access Journals (Sweden)

    André Luiz Lourenção

    1994-01-01

    Full Text Available A partir de 1991, tem sido observada a presença da mosca-branca Bemisia tabaci (Genn. (Homoptera: Aleyrodidae em altas populações em hortaliças e orna-mentais nos municípios paulistas de Paulínia, Holambra, Jaguariúna e Artur Nogueira. Foram constatadas infestações severas em tomateiro, brócolos, berinjela e aboboreira; nesta última, o sintoma observado em plantas infestadas pela mosca-branca é o prateamento da face superior das folhas, em conjunto com queda drástica da produção. Uma lavoura de tomate severamente infestada por B. tabaci apresentava o sintoma referido colo amadurecimento irregular dos frutos do tomateiro; plantas invasoras presentes nessa área também foram intensamente colonizadas, principalmente Sida rhombifolia L., Sonchus oleraceus L., Solanum viarum Dun. e Ipomoea acuminata Roem. & Schult. Em Holambra, verificaram-se ataques intensos em plantas ornamentais, principalmente crisântemo (Chrysantemum morifolium Ramat. e bico-de-papagaio (Euphorbia pulcherrima Willd.; roseiras foral pouco colonizadas. Nessas hortaliças e nas ornamentais, a aplicação quase diária de inseticidas não reduziu a infestação do inseto. Além dessas plantas, campos de algodão, em Holambra, e de feijão, em Paulínia, também foram infestados por B. tabaci. Nos E.U.A., a capacidade de certas populações de B. tabaci de induzir o prateamento da folha em aboboreira e de colonizar intensamente E. pulcherrima, entre outros fatores, têm levado à distinção do biótipo "B" ou "poinsétia", nome vulgar dessa euforbiácea; todavia, estudos recentes na Califórnia (E.U.A. mostram a possibilidade de se tratar de duas espécies distintas. Dada a similaridade entre as infestações associadas a B. tabaci que vêm ocorrendo naquele país e, mais recentemente, no Brasil, é provável que o biótipo B ou essa nova espécie tenha sido aqui introduzido.Since 1991, an increase in the populations of the whitefly Bemisia tabaci (Genn. (Homoptera

  12. The first transcriptomes from field-collected individual whiteflies ( Bemisia tabaci, Hemiptera: Aleyrodidae):  a case study of the endosymbiont composition

    Science.gov (United States)

    Ndunguru, Joseph; Tumuhimbise, Robooni; Tairo, Fred; Guo, Jian-Yang; Vrielink, Alice; Blythe, Amanda; Kinene, Tonny; De Marchi, Bruno; Kehoe, Monica A.; Tanz, Sandra; Boykin, Laura M.

    2018-01-01

    Background: Bemisia tabaci species ( B. tabaci), or whiteflies, are the world’s most devastating insect pests. They cause billions of dollars (US) of damage each year, and are leaving farmers in the developing world food insecure. Currently, all publically available transcriptome data for B. tabaci are generated from pooled samples, which can lead to high heterozygosity and skewed representation of the genetic diversity. The ability to extract enough RNA from a single whitefly has remained elusive due to their small size and technological limitations. Methods: In this study, we optimised a single whitefly RNA extraction procedure, and sequenced the transcriptome of four individual adult Sub-Saharan Africa 1 (SSA1) B. tabaci. Transcriptome sequencing resulted in 39-42 million raw reads. De novo assembly of trimmed reads yielded between 65,000-162,000 Contigs across B. tabaci transcriptomes. Results: Bayesian phylogenetic analysis of mitochondrion cytochrome I oxidase (mtCOI) grouped the four whiteflies within the SSA1 clade. BLASTn searches on the four transcriptomes identified five endosymbionts; the primary endosymbiont Portiera aleyrodidarum and four secondary endosymbionts: Arsenophonus, Wolbachia, Rickettsia, and Cardinium spp. that were predominant across all four SSA1 B. tabaci samples with prevalence levels of between 54.1 to 75%. Amino acid alignments of the NusG gene of P. aleyrodidarum for the SSA1 B. tabaci transcriptomes of samples WF2 and WF2b revealed an eleven amino acid residue deletion that was absent in samples WF1 and WF2a. Comparison of the protein structure of the NusG protein from P. aleyrodidarum in SSA1 with known NusG structures showed the deletion resulted in a shorter D loop. Conclusions: The use of field-collected specimens means time and money will be saved in future studies using single whitefly transcriptomes in monitoring vector and viral interactions. Our method is applicable to any small organism where RNA quantity has limited

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

  15. Whitefly (Bemisia tabaci Genn. , Stern. : Aleyrodidae) infestation patterns as influenced by cotton, weather and Heliothis: hypotheses testing by using simulation models

    Energy Technology Data Exchange (ETDEWEB)

    Baumgaertner, J.; Delucchi, V.; Von Arx, R.; Rubli, D.

    1986-01-01

    The whitefly Bemisia tabaci Genn. is an important pest on cotton in the Sudan Gezira. A population model based on the age-specific and time-varying life table approach has been constructed and validated for B. tabaci and the cotton variety Barac. Simulation experiments indicate that weather conditions are favourable for whitefly development until late autumn, when the bolls of early sown Barac open. Host plant quality, as measured by leaf age structure, is a very important factor in the B. tabaci life system. Reduced photosynthesis decreases and delays yield formation, but appears to have little effect on whitefly infestation levels at the time the bolls open. Simulated damage caused by Heliothis larvae to fruiting structures alters the growth of the plants, changes the age structures of the leaves and suggests increased whitefly numbers at the time of boll opening. 27 refs., 6 figs.

  16. 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.

  17. 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

    BACKGROUND: 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...

  18. 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 ...

  19. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  20. The Trouble with MEAM2: Implications of Pseudogenes on Species Delimitation in the Globally Invasive Bemisia tabaci (Hemiptera: Aleyrodidae) Cryptic Species Complex.

    Science.gov (United States)

    Tay, Wee Tek; Elfekih, Samia; Court, Leon N; Gordon, Karl H J; Delatte, Hélène; De Barro, Paul J

    2017-10-01

    Molecular species identification using suboptimal PCR primers can over-estimate species diversity due to coamplification of nuclear mitochondrial (NUMT) DNA/pseudogenes. For the agriculturally important whitefly Bemisia tabaci cryptic pest species complex, species identification depends primarily on characterization of the mitochondrial DNA cytochrome oxidase I (mtDNA COI) gene. The lack of robust PCR primers for the mtDNA COI gene can undermine correct species identification which in turn compromises management strategies. This problem is identified in the B. tabaci Africa/Middle East/Asia Minor clade which comprises the globally invasive Mediterranean (MED) and Middle East Asia Minor I (MEAM1) species, Middle East Asia Minor 2 (MEAM2), and the Indian Ocean (IO) species. Initially identified from the Indian Ocean island of Réunion, MEAM2 has since been reported from Japan, Peru, Turkey and Iraq. We identified MEAM2 individuals from a Peruvian population via Sanger sequencing of the mtDNA COI gene. In attempting to characterize the MEAM2 mitogenome, we instead characterized mitogenomes of MEAM1. We also report on the mitogenomes of MED, AUS, and IO thereby increasing genomic resources for members of this complex. Gene synteny (i.e., same gene composition and orientation) was observed with published B. tabaci cryptic species mitogenomes. Pseudogene fragments matching MEAM2 partial mtDNA COI gene exhibited low frequency single nucleotide polymorphisms that matched low copy number DNA fragments (species. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  1. Parâmetros biológicos de Bemisia Tabaci (genn. biótipo B (hemiptera: aleyrodidae em genótipos de algodoeiro Biological parameters of Bemisia Tabaci B biotype on cotton genotypes

    Directory of Open Access Journals (Sweden)

    Zeneide Ribeiro Campos

    2009-01-01

    Full Text Available A mosca-branca Bemisia tabaci biótipo B é uma praga de grande importância econômica para muitas culturas em todo o mundo. No Brasil, especialmente no Estado da Bahia, essa praga causou perdas que variam entre 30% e 70% em cultura de algodão. Essa pesquisa foi desenvolvida com o objetivo de avaliar parâmetros biológicos de B. tabaci biótipo B em genótipos de algodoeiro para verificar a possível ocorrência de antibiose como mecanismo de resistência sob condições de casa de vegetação. Os genótipos estudados foram IAC-23, Coodetec 406, BRS Aroeira, Fabrika, Coodetec 407, IAC-24, Makina, IAC 20-233, Coodetec 401 e CNPA Acala I. Foram avaliados os períodos de incubação e ninfal, o desenvolvimento total e a longevidade. Dos genótipos avaliados observou-se em Coodetec 406 maior período ninfal (14,7 dias e IAC-23 a menor viabilidade de ninfas (30,7%, indicando a ocorrência de resistência do tipo antibiose contra essa mosca-branca.The silverleaf whitefly Bemisia tabaci B biotype is an important pest of many crops throughout the world. In Brazil, specifically in the Bahia State, this insect caused losses estimated to 30-70% on cotton crops. The purpose of this research was to investigate biological parameters of the silverleaf whitefly biotype B in genotype of cotton bush to verify a possible occurrence of antibiosis as resistance mechanism cotton, under greenhouse conditions. The duration of the egg and nymphal stages, and the adult longevity of B. tabaci biotype B were evaluated in the genotypes IAC-23, Coodetec 406, BRS Aroeira, Fabrika, Coodetec 407, IAC-24, Makina, IAC 20-233, Coodetec 401 and CNPA Acala I. Among those evaluated genotypes, Coodetec 406 increased the nymph stage (14.7 days and IAC-23 reduced the nymphal viability (30.7%, suggesting the occurrence of antibiosis against this whitefly.

  2. Characteristics, phenotype, and transmission of Wolbachia in the sweet potato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), and its parasitoid Eretmocerus sp. nr. emiratus (Hymenoptera: Aphelinidae).

    Science.gov (United States)

    Chiel, Elad; Kelly, Suzanne E; Harris, Alexandre M; Gebiola, Marco; Li, Xianchun; Zchori-Fein, Einat; Hunter, Martha S

    2014-04-01

    Wolbachia is a common intracellular bacterial endosymbiont of insects, causing a variety of effects including reproductive manipulations such as cytoplasmic incompatibility (CI). In this study, we characterized Wolbachia in the whitefly Bemisia tabaci and in the whitefly parasitoid Eretmocerus sp. nr. emiratus. We also tested for horizontal transmission of Wolbachia between and within trophic levels, and we determined the phenotype of Wolbachia in E. sp. nr. emiratus. Using multilocus sequence typing and phylogenetic analyses, we found that B. tabaci and E. sp. nr. emiratus each harbor a different and unique strain of Wolbachia. Both strains belong to the phylogenetic supergroup B. No evidence for horizontal transmission of Wolbachia between and within trophic levels was found in our study system. Finally, crossing results were consistent with a CI phenotype; when Wolbachia-infected E. sp. nr. emiratus males mate with uninfected females, wasp progeny survival dropped significantly, and the number of females was halved. This is the first description of CI caused by Wolbachia in the economically important genus Eretmocerus. Our study underscores the expectation that horizontal transmission events occur rarely in the dynamics of secondary symbionts such as Wolbachia, and highlights the importance of understanding the effects of symbionts on the biology of natural enemies.

  3. POTENCY OF PREDATOR (Menochilus sexmaculatus AUGMENTATION FOR WHITE FLY (Bemisia tabaci MANAGEMENT AND ITS EFFECT ON GEMINI VIRUS INFESTATION ON TOMATO

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    W. Setiawati

    2013-04-01

    Full Text Available Bemisia tabaci (Gen. (Homoptera: Aleyrodidae is one of the most serious pests on tomato. It is mainly controlled by chemi-cal means, requiring some 25 sprays during the average growing season. The extensive and repeated use of insecticides has dis-rupted the natural balance between this pest and its natural enemies. In this study, Menochilus sexmaculatus F. was evalu-ated as a possible biological control agent of B. tabaci and its effect on Gemini virus infestation. The study was conducted at the experimental station of the Indonesian Vegetables Research Institute (IVeGRI in Lembang, West Java (1,250 m above sea level from August to December 2008. The experimental plots consisted of 0.35 ha of tomato (± 100 m2 per plot and spatially separated with four rows of maize (a minimum of 1 m inter-plot distance to prevent cross-contamination among plots. The experiment was arranged in completely randomized block design with eight treatments and four replications. M. sexmaculatus were released at 24 days after planting. The treatments were designed according dosages and schedules at three released populations (i.e. 10 predators per plot, 20 predators per plot, and 10 predators per plot at vegetative stage followed by 20 predators per plot at generative stage; two places of release (center and edge of the plot; and two schedules of release (weekly and biweekly. Efficacy of the predator was measured in terms of the density of B. tabaci, both before and after release of the predator and its effect on Gemini virus infestation. The result indicated the potential use of M. sexmaculatus to control B. tabaci and its effect on Gemini virus infestation on tomato. Reductions in B. tabaci populations and subsequent tomato yields were significant. B. tabaci population in plots receiving 10 predators showed 73.62% and 75.75% reductions by the end of experiment. The incidence and intensity of Gemini virus were consistently and significantly lowest and tomato yield

  4. 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...... were collected from cassava plants, intercrops and weeds in and surrounding cassava fields. Insects collected in this way were subjected to molecular analyses using mitochondrial and nuclear markers. The four B. tabaci putative species found to be present in the study area, based on mitochondrial data...... are conferred with increased fitness. Only by understanding the vector better can we design integrated pest management strategies to stop the spread of the severe CMD pandemic that continues to threaten the food security of several millions of people in sub-Saharan Africa. This work was the first study...

  5. Evaluation of Bioinsecticides for Management of Bemisia tabaci (Hemiptera: Aleyrodidae) and the Effect on the Whitefly Predator Delphastus catalinae (Coleoptera: Coccinellidae) in Organic Squash.

    Science.gov (United States)

    Razze, Janine M; Liburd, Oscar E; Nuessly, Gregg S; Samuel-Foo, Michelle

    2016-08-01

    Organic zucchini squash is a high-value vegetable crop in Florida and potential exists to expand its production throughout the state. A lack of knowledge on the effectiveness of organic products and their integration with natural enemies is an important constraint to the regulation of pest populations in organic squash production in Florida. The objectives of this study were to evaluate the effect of insecticides labeled for organic production that can be used for management of Bemisia tabaci (Gennadius) biotype B, on organically grown squash; and to determine the effects of the most efficient insecticides on a key natural enemy, Delphastus catalinae (Horn). Experiments were conducted in the greenhouse in exclusion cages. The first experiment compared the effects of four bioinsecticides on whitefly densities. Insecticides include 1) AzaSol (azadirachtin), 2) PyGanic EC 1.4 (pyrethrin), 3) M-Pede (insecticidal soap), and 4) Entrust (spinosad). The second experiment investigated the effects of bioinsecticides on D. catalinae Treatment effectiveness was evaluated 1, 3, and 5 d posttreatment. PyGanic and M-Pede were highly effective in controlling whitefly populations on organic squash, while moderate control was provided by AzaSol and there was no control provided by Entrust. PyGanic and M-Pede treatments reduced D. catalinae populations when adults were released 1 d post pesticide application. However, when adults were released 5 d post application, there was no reduction. The importance of using bioinsecticides in combination with natural enemies to regulate pest populations in organic cropping systems is discussed. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Effectiveness of Cyantraniliprole for Managing Bemisia tabaci (Hemiptera: Aleyrodidae) and Interfering with Transmission of Tomato Yellow Leaf Curl Virus on Tomato.

    Science.gov (United States)

    Caballero, Rafael; Schuster, David J; Peres, Natalia A; Mangandi, Jozer; Hasing, Tomas; Trexler, Fred; Kalb, Steve; Portillo, Héctor E; Marçon, Paula C; Annan, I B

    2015-06-01

    Cyantraniliprole is the second xylem-systemic active ingredient in the new anthranilic diamide class. Greenhouse (2006), growth chamber (2007), and field studies (2009-2010) were conducted to determine the efficacy of cyantraniliprole for managing Bemisia tabaci (Gennadius) biotype B and in interfering with transmission of tomato yellow leaf curl virus (TYLCV) by this whitefly. Cyantraniliprole applied as soil treatments (200 SC) or foliar sprays (100 OD) provided excellent adult whitefly control, TYLCV suppression, and reduced oviposition and nymph survival, comparable to current standards. The positive results observed in these greenhouse experiments with a high level of insect pressure (10× the field threshold of one adult per plant) and disease pressure (five adults per plant, with a high level of confidence that TYLCV virulent adults were used), indicate a great potential for cyantraniliprole to be used in a whitefly management program. Field evaluations of soil drench treatments confirmed the suppression of TYLCV transmission demonstrated in the greenhouse studies. Field studies in 2009 and 2010 showed that cyantraniliprole (200 SC) provided TYLCV suppression for 2 wk after a drench application, when using a susceptible (2009) or imidacloprid-tolerant (2010) whitefly population. Cyantraniliprole was demonstrated to be a promising tool for management of TYLCV in tomato production, which is very difficult and expensive, and which has limited options. The integration of cyantraniliprole into a resistance management program will help to ensure the continued sustainability of this and current insecticides used for the management of insect vectors, including whiteflies and the TYLCV they spreads. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. 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

    Directory of Open Access Journals (Sweden)

    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.

  8. Effect of climate change on Bemisia tabaci in Southeastern USA

    Science.gov (United States)

    Traditional and molecular approaches can be used to improve cultivated watermelon (Citrullus lanatus var. lanatus) against whiteflies. The Bemisia tabaci (Hemiptera: Aleyrodidae) whitefly complex attacks many crops on a global scale. It is very adaptive, and it feeds on over 1,000 diverse species of...

  9. 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

    Directory of Open Access Journals (Sweden)

    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

  10. Influence of pesticide treatments on the dynamics of whiteflies and associated parasitoids in snap bean fields

    NARCIS (Netherlands)

    Manzano, M.R.; Lenteren, van J.C.; Cardona, C.

    2003-01-01

    To determine the influence of pesticide treatments on the population dynamics of the whiteflies Trialeurodes vaporariorum (Westwood) and Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) and their naturally occurring parasitoids, we performed field experiments on insecticide sprayed and unsprayed

  11. Intraguild predation by the generalist predator Orius majusculus on the parasitoid Encarsia formosa

    DEFF Research Database (Denmark)

    Sohrabi, Fariba; Enkegaard, Annie; Shishehbor, Parviz

    2013-01-01

    Intraguild predation of Orius majusculus (Reuter) (Heteroptera: Anthocoridae) on Encarsia formosa (Gahan) (Hymenoptera: Aphelinidae), both natural enemies of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), was studied under laboratory conditions. The experiments quantified prey consumption b...

  12. Search capacity, prey preference, predation rates and reaction to prey and predator induced volatiles of predatory mirids of two tomato pests, Tuta absoluta (Lep.: Gelechiidae) and Bemisia tabaci (Hem.: Aleyrodidae)

    OpenAIRE

    Lins Júnior, Juracy Caldeira

    2014-01-01

    A traça-do-tomateiro Tuta absoluta (Meyrick) e a mosca-branca Bemisia tabaci (Gennadius) são pragas chave na cultura do tomate. O uso de inseticidas é a principal estratégia de controle dessas pragas no Brasil, enquanto que na Europa os mirídeos predadores Macrolophus pygmaeus Rambour e Nesidiocoris tenuis (Reuter) são comercializados para o controle biológico dessas pragas. No Brasil, foram recentemente encontrados três mirídeos [Campyloneuropsis infumatus (Carvalho), Engyt...

  13. Efeito de óleos essenciais e extratos de diferentes espécies botânicas sobre bemisia tabaci (Gennadius) biótipo b (Hemiptera: aleyrodidae) em tomateiro

    OpenAIRE

    Fanela, Thiago Luis Martins [UNESP

    2012-01-01

    A mosca-branca, Bemisia tabaci (Gennadius) biótipo B, é uma praga de grande importância na cultura do tomateiro em todos os sistemas de cultivo. O controle é feito, comumente, utilizando-se inseticidas sintéticos; entretanto, devido aos conhecidos problemas socioambientais que essa tática apresenta, justifica-se o desenvolvimento de métodos alternativos de controle. O presente trabalho teve por objetivo avaliar o efeito de extratos aquosos a 3% e óleos essenciais em diferentes concentrações p...

  14. Bases ecológicas para o manejo de Bemisia tabaci (Genn.) biótipo B (Hemiptera: Aleyrodidae) em sistemas orgânicos de produção de tomate

    OpenAIRE

    Togni, Pedro Henrique Brum

    2010-01-01

    A mosca-branca Bemisia tabaci biótipo B é considerada uma das principais pragas do tomateiro por causar perdas de produtividade devido a danos diretos e pela transmissão de diversas viroses (Geminiviridae). As aplicações de inseticidas para seu controle têm se mostrado cada vez mais incipientes. Isso evidencia a necessidade de novas técnicas de manejo baseado nas interações ecológicas entre a mosca-branca e outros componentes bióticos e abióticos do agroecossistema do tomateiro. Em estudos an...

  15. Update on the Status of Bemisia tabaci in the UK and the Use of Entomopathogenic Fungi within Eradication Programmes

    Directory of Open Access Journals (Sweden)

    Andrew G. S. Cuthbertson

    2013-05-01

    Full Text Available The sweetpotato whitefly Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae continues to be a serious threat to crops worldwide. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. Both B and Q Bemisia biotypes are now regularly intercepted entering the UK. With increasing reports of neonicotinoid resistance in both these biotypes, it is becoming more problematic to control/eradicate. Therefore, alternative means of control are necessary. Entomopathogenic fungi (Lecanicilllium muscarium and Beauveria bassiana offer much potential as control agents of B. tabaci within eradication programmes in the UK.

  16. Update on the Status of Bemisia tabaci in the UK and the Use of Entomopathogenic Fungi within Eradication Programmes

    Science.gov (United States)

    Cuthbertson, Andrew G. S.

    2013-01-01

    The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) continues to be a serious threat to crops worldwide. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. Both B and Q Bemisia biotypes are now regularly intercepted entering the UK. With increasing reports of neonicotinoid resistance in both these biotypes, it is becoming more problematic to control/eradicate. Therefore, alternative means of control are necessary. Entomopathogenic fungi (Lecanicilllium muscarium and Beauveria bassiana) offer much potential as control agents of B. tabaci within eradication programmes in the UK. PMID:26464385

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

    DEFF Research Database (Denmark)

    Riis, Lisbeth; Nachman, Gösta

    2006-01-01

    1 The ability to quantify whitefly migration provides a tool that can contribute to an improved understanding of the epidemic development of whitefly-transmitted viruses. 2 In an attempt to develop a protocol for estimating whitefly immigration and emigration rates in an annual crop, new traps...... 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...... away from the crop. Captures on these traps could not categorically be identified as immigrants or emigrants, but the cumulated captures nevertheless explained 66% of the variation in population density found within the field. Hence, window traps may be used as an efficient and reliable alternative...

  18. Population variability of Bemisia tabaci (Genn.) in different hosts.

    Science.gov (United States)

    do Valle, G E; Lourenção, A L; Zucchi, M I; Pinheiro, J B; de Abreu, A G

    2013-10-17

    The silverleaf whitefly, Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae), is a cryptic species complex that contains some of the most damaging pests in tropical and subtropical regions. Recent studies have indicated that this complex is composed of at least 24 distinct and morphologically indistinguishable species that mainly differ in their ability to transmit phytoviruses, adapt to hosts, and induce physiological changes in certain hosts. The importance of this species has been increasing worldwide, because it serves as a phytovirus vector, particularly for geminiviruses, in economically important crops. Here, we aimed to examine the population variability of B. tabaci populations inhabiting 6 agricultural crops grown in 5 regions of Brazil and 1 region of the USA; BRrep [Brasília (DF, Brazil) - cabbage], ILsoj [Urbana (IL/USA) - soybean], BJabo [Bom Jesus da Lapa (BA, Brazil) - pumpkin], CPsoj [Campinas (SP, Brazil) - soybean], UBman [Ubatuba (SP, Brazil) - cassava], and PEmel [Petrolina (PE, Brazil) - melon]. Thirteen polymorphic loci with 50 alleles were observed, with an average of 2.37 (range: 2.00-2.91) alleles per population. The UBman and PEmel B. tabaci populations were the most differentiated, which was probably caused by insect adaptation to the host plant and the use of insecticides. A 33.87% inter-population variation was observed, indicating that microsatellites may be used to measure differentiation among these B. tabaci populations. Based on the comparison of microsatellites in the current study, only the Middle East-Asia Minor 1 population of B. tabaci was found in the six populations.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. ASSESSING Bemisia tabaci (GENN.) BIOTYPE B RESISTANCE IN SOYBEAN GENOTYPES: ANTIXENOSIS AND ANTIBIOSIS

    OpenAIRE

    Goncalves Franco da Silva, Jose Paulo; Lopes Baldin, Edson Luiz; de Souza, Efrain Santana; Lourencao, Andre Luiz

    2012-01-01

    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 wh...

  1. Control of whiteflies and aphids in tomato ( Solanum lycopersicum L ...

    African Journals Online (AJOL)

    Whitefly (Bemisia tabaci, Homoptera: Aleyrodidae) and aphid (Homoptera) on tomato (Solanum lycopersicum L.) are economically important insect pests that are difficult to manage due to their resistance to a wide range of chemical pesticides. Field experiments were conducted to assess the effects of fermented plant ...

  2. Distribution of Bemisia tabaci Genetic Groups in India.

    Science.gov (United States)

    Ellango, R; Singh, Shalini Thakur; Rana, Vipin Singh; Gayatri Priya, N; Raina, Harpreet; Chaubey, Rahul; Naveen, N C; Mahmood, Riaz; Ramamurthy, V V; Asokan, R; Rajagopal, R

    2015-08-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a phloem-feeding, economically important pest of crops worldwide. In addition to direct damage, it also vectors a number of plant viruses belonging to the family Geminiviridae. Its populations differ biologically with respect to insecticide resistance, virus transmission and host range. Therefore, understanding genetic variation among populations is important for management. We sequenced 850 bp of the mitochondrial COI (mtCOI) gene from B. tabaci populations surveyed across India. BLAST analysis of the mtCOI sequences generated in this study with sequences from the mtCOI dataset showed the presence of one invasive group, MEAM1, and eight other groups of B. tabaci in India. mtCOI sequence analyses showed the presence of Asia I, Asia I-India, Asia II-1, Asia II-5, Asia II-7, Asia II-8, and Asia II-11 genetic groups. We also found China-3 in a field in Birbhum district, West Bengal, India, suggesting a role of anthropogenic activities in the distribution of B. tabaci. Interestingly, more than one genetic group was found coexisting in the same field. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. 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

    OpenAIRE

    José Paulo Gonçalves Franco da Silva; Edson Luiz Lopes Baldin; Efrain Santana de Souza; André Luiz Lourenção

    2012-01-01

    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 whit...

  4. Performance of Bemisia tabaci Biotype B on Soybean Genotypes.

    Science.gov (United States)

    Cruz, P L; Baldin, E L L

    2017-04-01

    Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) has been recognized as an important pest of many agricultural systems including soybean [Glycine max (L.) Merrill] crops. As an alternative to chemical control, the use of resistant genotypes represents an important tool for integrated pest management (IPM). This study aimed to evaluate the biological development of Bemisia tabaci biotype B confined on 13 soybean genotypes under greenhouse conditions. Initially, the nymphal period, complete development period (egg-adult), and the viability of the silverleaf whitefly nymphs were evaluated in all genotypes. Then, four genotypes promising for resistance ('Jackson,' UX-2569-159, 'P98Y11,' and 'TMG132 RR') and a susceptible genotype (PI-227687) were selected for further assays, where two insect populations were compared: a first population from the initial rearing (cabbage plants) and another corresponding to insects previously reared out on the selected genotypes. In addition to the parameters evaluated in preliminary tests, we also determined the viability and incubation period of eggs. Moderate levels of resistance (antibiosis/antixenosis) to B. tabaci biotype B were found in three genotypes. 'P98Y11' and 'TMG132 RR' were less suitable for insect development, extending the development cycle, and UX-2569-159 caused high nymphal mortality. We did not observe a significant increase in the level of plant resistance by the use of previously stressed insects. This suggests that the evaluation of a single whitefly generation may be sufficient to make correct decisions on promising soybean genotypes.

  5. The draft genome of whitefly Bemisia tabaci MEAM1, a global crop pest, provides novel insights into virus transmission, host adaptation, and insecticide resistance.

    Science.gov (United States)

    Chen, Wenbo; Hasegawa, Daniel K; Kaur, Navneet; Kliot, Adi; Pinheiro, Patricia Valle; Luan, Junbo; Stensmyr, Marcus C; Zheng, Yi; Liu, Wenli; Sun, Honghe; Xu, Yimin; Luo, Yuan; Kruse, Angela; Yang, Xiaowei; Kontsedalov, Svetlana; Lebedev, Galina; Fisher, Tonja W; Nelson, David R; Hunter, Wayne B; Brown, Judith K; Jander, Georg; Cilia, Michelle; Douglas, Angela E; Ghanim, Murad; Simmons, Alvin M; Wintermantel, William M; Ling, Kai-Shu; Fei, Zhangjun

    2016-12-14

    The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is among the 100 worst invasive species in the world. As one of the most important crop pests and virus vectors, B. tabaci causes substantial crop losses and poses a serious threat to global food security. We report the 615-Mb high-quality genome sequence of B. tabaci Middle East-Asia Minor 1 (MEAM1), the first genome sequence in the Aleyrodidae family, which contains 15,664 protein-coding genes. The B. tabaci genome is highly divergent from other sequenced hemipteran genomes, sharing no detectable synteny. A number of known detoxification gene families, including cytochrome P450s and UDP-glucuronosyltransferases, are significantly expanded in B. tabaci. Other expanded gene families, including cathepsins, large clusters of tandemly duplicated B. tabaci-specific genes, and phosphatidylethanolamine-binding proteins (PEBPs), were found to be associated with virus acquisition and transmission and/or insecticide resistance, likely contributing to the global invasiveness and efficient virus transmission capacity of B. tabaci. The presence of 142 horizontally transferred genes from bacteria or fungi in the B. tabaci genome, including genes encoding hopanoid/sterol synthesis and xenobiotic detoxification enzymes that are not present in other insects, offers novel insights into the unique biological adaptations of this insect such as polyphagy and insecticide resistance. Interestingly, two adjacent bacterial pantothenate biosynthesis genes, panB and panC, have been co-transferred into B. tabaci and fused into a single gene that has acquired introns during its evolution. The B. tabaci genome contains numerous genetic novelties, including expansions in gene families associated with insecticide resistance, detoxification and virus transmission, as well as numerous horizontally transferred genes from bacteria and fungi. We believe these novelties likely have shaped B. tabaci as a highly invasive polyphagous crop pest and

  6. Compatibilidad de Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) y Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae), importantes enemigos naturales de la mosca blanca Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) en cultivos hortícolas, con nuevas barreras físicas selectivas y modernos plaguicidas

    OpenAIRE

    Fernández Gallego, María del Mar

    2016-01-01

    Los programas de Gestión Integrada de Plagas (GIP) promueven el uso de estrategias de control que sean respetuosas con el medio ambiente, sin embargo el uso de insecticidas en los cultivos hortícolas sigue siendo necesario para el control de determinadas plagas, como es el caso de la mosca blanca Bemisia tabaci (Gennadius). Por ello, el objetivo de esta tesis es el estudio de la integración de las tres estrategias de control más empleadas hoy en día para el control de plagas: el control bioló...

  7. Author Details

    African Journals Online (AJOL)

    Wester2, D. Vol 17, No 1 (2010) - Articles Strip Cropping: A Potential IPM Tool for Reducing Whitefly, Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) Infestations in Cassava Abstract PDF. ISSN: 0855-4307. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More ...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Shi, Xiaobin; Chen, Gong; Tian, Lixia; Peng, Zhengke; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2016-01-01

    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. PMID:27376280

  10. Bemisia tabaci nomenclature: lessons learned.

    Science.gov (United States)

    Boykin, Laura M

    2014-10-01

    The nomenclature used within the whitefly research community for different putative species within Bemisia tabaci (sensu Russell) remains highly variable and confused. This was evident by the many different naming schemes researchers were using in their presentations at the 1st International Whitefly Symposium in Kolymbari, Crete, Greece (20-24 May 2013). I wanted to try to document how we, as a community, have arrived at such a state of confused nomenclature. This also included an investigation of the nomenclature used in the literature (from 2002 to 2012) by means of two online search tools (Web of Science and Scirus). Nomenclatural data were collected at the 1st International Whitefly Symposium, based on oral presentations and posters. There were 17 different names used for the MED species and 12 different names used for the MEAM1 species of the B. tabaci species complex. Investigation of the literature revealed limited uptake of the intermediate names. The intermediate names for the various species in the B. tabaci species complex - MED, MEAM1, New World, etc. - are not being used by the wider whitefly community. To move forwarrd as a community, we must work towards a formal revision of the B. tabaci complex. © 2013 Society of Chemical Industry.

  11. Diversity and localization of bacterial symbionts in three whitefly species (Hemiptera: Aleyrodidae) from the east coast of the Adriatic Sea.

    Science.gov (United States)

    Skaljac, M; Zanić, K; Hrnčić, S; Radonjić, S; Perović, T; Ghanim, M

    2013-02-01

    Several whitefly species (Hemiptera: Aleyrodidae) are cosmopolitan phloem-feeders that cause serious damage in numerous agricultural crops. All whitefly species harbor a primary bacterial symbiont and a diverse array of secondary symbionts which may influence several aspects of the insect's biology. We surveyed infections by secondary symbionts in Bemisia tabaci (Gennadius), Trialeurodes vaporariorum (Westwood) and Siphoninus phillyreae (Haliday) from areas in the east cost of the Adriatic Sea. Both the Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED) B. tabaci genetic groups were detected in Montenegro, whereas only the MED was confirmed in Croatia. Trialeurodes vaporariorum and S. phillyreae were found in all areas surveyed. MEAM1 and MED exhibited similarity to previously reported infections, while populations of T. vaporariorum from Montenegro harbored Rickettsia, Wolbachia and Cardinium in addition to previously reported Hamiltonella and Arsenopnohus. Siphoninus phillyreae harbored Hamiltonella, Wolbachia, Cardinium and Arsenophonus, with the latter appearing in two alleles. Multiple infections of all symbionts were common in the three insect species tested, with some reaching near fixation. Florescent in situ hybridization showed new localization patterns for Hamiltonella in S. phillyreae, and the morphology of the bacteriosome differed from that observed in other whitefly species. Our results show new infections with bacterial symbionts in the whitefly species studied. Infections with the same symbionts in reproductively isolated whitefly species confirm complex relationships between whiteflies and bacterial symbionts, and suggest possible horizontal transfer of some of these bacteria.

  12. Resistência de genótipos de feijoeiro a Bemisia tabaci biótipo B Resistance of bean genotypes to Bemisia tabaci biotype B

    Directory of Open Access Journals (Sweden)

    Lucas Castro Torres

    2012-01-01

    Full Text Available O estudo de genótipos de feijoeiro resistentes à mosca-branca Bemisia tabaci (Genn. biótipo B (Hemiptera: Aleyrodidae é de grande importância devido aos danos ocasionados por essa praga à cultura. Neste trabalho, foram estudados a atratividade para adultos, a preferência para oviposição em testes com e sem chance de escolha, o ciclo ovo-adulto e o tipo e número de tricomas presentes nos folíolos. Os experimentos foram realizados em casa de vegetação avaliando-se, inicialmente, cem genótipos de feijoeiro. A resistência do tipo não-preferência para alimentação e/ou antibiose foi observada nos genótipos ARC-3, IAC-Alvorada e Canário 101, sendo a emergência de adultos fortemente influenciada pelos genótipos. Também se observou correlação negativa moderada entre o número de ovos e o número de tricomas glandulares, e correlação positiva muito forte entre o número de ovos e o número de tricomas tectores unciformes.The study of bean genotypes resistant to the whitefly Bemisia tabaci (Genn. B biotype (Hemiptera: Aleyrodidae has been of great importance due to the damage caused by this pest. In this research, bean genotypes were evaluated regarding attractiveness to whitefly adults, the preference for oviposition in free-choice and non choice tests, egg-to-adult development time and characterized for the presence, type and number of trichomes. The experiments were carried out under greenhouse conditions initially evaluating 100 bean genotypes. The non-preference type of resistance for feeding and/or antibiosis was observed in the genotypes ARC-3, IAC-Alvorada and Canário 101, and the emergence of adults was strongly influenced by the genotypes. It was also observed a moderate negative correlation between the number of eggs and the number of glandular trichomes, as well as a very strong positive correlation between the number of eggs and the number of unciform non-glandular trichomes.

  13. Dynamics of biotypes B and Q of the whitefly Bemisia tabaci and its impact on insecticide resistance.

    Science.gov (United States)

    Horowitz, Abraham Rami; Ishaaya, Isaac

    2014-10-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a key pest in many agricultural crops, including vegetables, ornamentals and field crops. B. tabaci is known for its genetic diversity, which is expressed in a complex of biotypes or, as recently suggested, a complex of distinct cryptic species. The biotypes are largely differentiated on the basis of biochemical or molecular polymorphism and differ in characteristics such as host plant range, attraction by natural enemies, secondary symbionts and expression of insecticide resistance. An extensive survey of B. tabaci biotypes and their impact on insecticide resistance was conducted from 2003 to 2012 in cotton fields and other crops from several locations in Israel. Two biotypes of B. tabaci, B and Q, were identified, and some differences in the biotype dynamics were recorded from different areas. In northern Israel from 2003 to 2007, a higher proportion of the B biotype was consistently found in early season. However, by the end of the season a definite rise of the Q biotype was sampled, ranging from 60 to 100%, along with high resistance to the insect growth regulator (IGR) pyriproxyfen and to a lesser extent to the neonicotinoid insecticides. In fields located in the central part of Israel, the Q biotype was predominant throughout the seasons, with high resistance to pyriproxyfen. Since 2009, a significant shift in the biotype ratios has been observed: the B biotype has come to predominate over the Q biotype ranging up to 90% or more in most fields. At the same time, resistance to the IGR pyriproxyfen was reduced considerably. The possible reasons for the change in the dynamics of B. tabaci biotypes, and its implications for resistance management, are discussed. Strong B. tabaci resistance to pyriproxyfen in Israel has been associated with the Q rather than with the B biotype. The B biotype is more competitive than the Q biotype under untreated conditions. Reduction in the acreage of cotton fields

  14. 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...

  15. Identification and Evaluation of Suitable Reference Genes for Gene Expression Studies in the Whitefly Bemisia tabaci (Asia I) by Reverse Transcription Quantitative Real-Time PCR

    Science.gov (United States)

    Collins, Carl; Patel, Mitulkumar V.; Colvin, John; Bailey, David; Seal, Susan

    2014-01-01

    This study presents a reliable method for performing reverse transcription quantitative real-time PCR (RT-qPCR) to measure gene expression in the whitefly Bemisia tabaci (Asia I) (Gennadius) (Hemiptera: Aleyrodidae), utilising suitable reference genes for data normalisation. We identified orthologs of commonly used reference genes (actin (ACT), cyclophilin 1 (CYP1), elongation factor 1α (EF1A), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), ribosomal protein L13a (RPL13A), and α-tubulin (TUB1A)), measured the levels of their transcripts by RT-qPCR during development and in response to thermal stress, and evaluated their suitability as endogenous controls using geNorm, BestKeeper, and NormFinder programs. Overall, TUB1A, RPL13A, and CYP1 were the most stable reference genes during B. tabaci development, and TUB1A, GAPDH, and RPL13A were the most stable reference genes in the context of thermal stress. An analysis of the effects of reference gene choice on the transcript profile of a developmentally-regulated gene encoding vitellogenin demonstrated the importance of selecting the correct endogenous controls for RT-qPCR studies. We propose the use of TUB1A, RPL13A, and CYP1 as endogenous controls for transcript profiling studies of B. tabaci development, whereas the combination of TUB1A, GAPDH, and RPL13A should be employed for studies into thermal stress. The data presented here will assist future transcript profiling studies in whiteflies.

  16. Evolutionary aspects of acoustic communication in Ribautodelphax planthoppers (Homoptera, Delphacidae)

    NARCIS (Netherlands)

    Winter, de A.J.

    1994-01-01

    Delphacidae (Homoptera), commonly referred to as planthoppers, are herbivores, which usually feed on grasses and sedges. During sexual behaviour males and females communicate by exchanging low-frequency vibrational signals, which are transmitted through the substrate, normally the host

  17. Further insight into reproductive incompatibility between putative cryptic species of the Bemisia tabaci whitefly complex.

    Science.gov (United States)

    Qin, Li; Pan, Li-Long; Liu, Shu-Sheng

    2016-04-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), with its global distribution and extensive genetic diversity, is now known to be a complex of over 35 cryptic species. However, a satisfactory resolution of the systematics of this species complex is yet to be achieved. Here, we designed experiments to examine reproductive compatibility among species with different levels of mitochondrial cytochrome oxidase I (mtCOI) divergence. The data show that putative species with mtCOI divergence of >8% between them consistently exhibited complete reproductive isolation. However, two of the putative species, Asia II 9 and Asia II 3, with mtCOI divergence of 4.47% between them, exhibited near complete reproductive compatibility in one direction of their cross, and partial reproductive compatibility in the other direction. Together with some recent reports on this topic from the literature, our data indicates that, while divergence in the mtCOI sequences provides a valid molecular marker for species delimitation in most clades, more genetic markers and more sophisticated molecular phylogeny will be required to achieve adequate delimitation of all species in this whitefly complex. While many attempts have been made to examine the reproductive compatibility among genetic groups of the B. tabaci complex, our study represents the first effort to conduct crossing experiments with putative species that were chosen with considerations of their genetic divergence. In light of the new data, we discuss the best strategy and protocols to conduct further molecular phylogenetic analysis and crossing trials, in order to reveal the overall pattern of reproductive incompatibility among species of this whitefly complex. © 2015 Institute of Zoology, Chinese Academy of Sciences.

  18. Gene expression profiling in the thiamethoxam resistant and susceptible B-biotype sweetpotato whitefly, Bemisia tabaci.

    Science.gov (United States)

    Xie, Wen; Yang, Xin; Wang, Shao-Ii; Wu, Qing-jun; Yang, Ni-na; Li, Ru-mei; Jiao, Xiao-guo; Pan, Hui-peng; Liu, Bai-ming; Feng, Yun-tao; Xu, Bao-yun; Zhou, Xu-guo; Zhang, You-jun

    2012-01-01

    Thiamethoxam has been used as a major insecticide to control the B-biotype sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Due to its excessive use, a high level of resistance to thiamethoxam has developed worldwide over the past several years. To better understand the molecular mechanisms underlying this resistance in B. tabaci, gene profiles between the thiamethoxam-resistant and thiamethoxam-susceptible strains were investigated using the suppression subtractive hybridization (SSH) library approach. A total of 72 and 52 upand down-regulated genes were obtained from the forward and reverse SSH libraries, respectively. These expressed sequence tags (ESTs) belong to several functional categories based on their gene ontology annotation. Some categories such as cell communication, response to abiotic stimulus, lipid particle, and nuclear envelope were identified only in the forward library of thiamethoxam-resistant strains. In contrast, categories such as behavior, cell proliferation, nutrient reservoir activity, sequence-specific DNA binding transcription factor activity, and signal transducer activity were identified solely in the reverse library. To study the validity of the SSH method, 16 differentially expressed genes from both forward and reverse SSH libraries were selected randomly for further analyses using quantitative realtime PCR (qRT-PCR). The qRT-PCR results were fairly consistent with the SSH results; however, only 50% of the genes showed significantly different expression profiles between the thiamethoxam-resistant and thiamethoxam-susceptible whiteflies. Among these genes, a putative NAD-dependent methanol dehydrogenase was substantially over-expressed in the thiamethoxamresistant adults compared to their susceptible counterparts. The distributed profiles show that it was highly expressed during the egg stage, and was most abundant in the abdomen of adult females.

  19. 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.

  20. 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

  1. 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

    Directory of Open Access Journals (Sweden)

    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

  2. Adubação e inseticidas no controle de Empoasca kraemeri e Bemisia tabaci, em cultivares de feijoeiro semeados no inverno Bean cultivars, fertilization and insecticides on the control of Empoasca kraemeri and Bemisia tabaci in the winter season

    Directory of Open Access Journals (Sweden)

    Arlindo Leal Boiça Jr.

    2000-12-01

    Full Text Available Vários fatores influenciam a produtividade da cultura do feijoeiro, dentre estes podem ser citados as pragas, merecendo destaque, a cigarrinha verde, Empoasca kraemeri Ross & Moore (Hemiptera: Cicadellidae e principalmente a mosca branca, Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae, que prejudica o feijoeiro pela transmissão do vírus do mosaico dourado. Este trabalho avalia o efeito de cultivares de feijoeiro, adubação e inseticidas nas populações de E. kraemeri e B. tabaci na época de semeadura "de inverno". Os genótipos utilizados foram IAPAR MD-806, IAPAR MD-808, IAC-Carioca e Bolinha. Avaliaram-se, dos 7 aos 56 dias após emergência das plantas, o número de ninfas e adultos de cigarrinha verde e mosca branca, percentual de ataque de cigarrinha e número de plantas com sintomas de mosaico dourado. Na colheita, foram avaliados o número e peso de vagens por planta, o número de grãos por planta e peso de grãos (kg ha-1. Os danos de cigarrinha verde e os sintomas de mosaico dourado foram menos intensos em IAPAR MD-806 e IAPAR MD-808 em relação ao Bolinha e IAC-Carioca. A adubação não influenciou o número médio de adultos de cigarrinha verde nos genótipos de feijoeiro. As aplicações de inseticidas e adubo proporcionaram menores números médios de adultos de mosca branca nos genótipos de feijoeiro quando avaliados em conjunto aos 56 dias após emergência das plantas.The productivity of bean crops is influenced by many factors, among them pests, in particular the leafhopper Empoasca kraemeri Ross & Moore (Hemiptera: Cicadellidae, and mainly the white fly Bemisia tabaci (Gennadius, 1889 (Hemiptera: Aleyrodidae that damages the bean crop transmitting the golden mosaic virus. The aim of the present study was to evaluate the effect of bean cultivars, chemical fertilizer and insecticides on E. kraemeri and B. tabaci populations during the winter season. The genotypes IAPAR MD-806, IAPAR MD-808, and IAC-Carioca and

  3. Biological traits and Life table parameters A and B biotype of Bemisia tabaci (Genn. on cotton and rapeseed

    Directory of Open Access Journals (Sweden)

    Mohammad Amin Samih

    2014-06-01

    Full Text Available The aim of this work was to construct life table of Bemisia tabaci (Gen. A and B (silverleaf whitefly B. argentifolii Bellows and Perring biotype (Hem.: Aleyrodidae on two host plants; cotton, (Gossypium hirsutum L. and rapeseed, (Brassica napus L.. Experiments were conducted in a growth chamber under 24 ± 2ºC, 55±3% RH and 16:8 (L:D h photoperiod on caged plants of cotton G. hirsutum L. (Varamin 76 variety and rapeseed B. napus L. (global variety. The intrinsic rate of natural increase (r m, net reproductive rate (R0 and mean generation time (T for B. tabaci A biotype was 0.1010 females per female per day, 18.4075 females per female and 30.079 day (d on cotton; 0.1286, 30.6760 and 26.77 d on rapeseed; and for B biotype (B. argentifolii those above respective parameters averaged 0.1033, 27.8426 and 32.74 d on cotton and 0.1750, 40.75 and 21.27 d on rapeseed. The total survival of A and B biotype from the egg to adult on cotton was 22.08 and 22.25, respectively. The results showed significant differences between the two biotype reared on either host plant for gross reproductive rate (GRR, net reproductive rate (R0 or NRR, intrinsic rates of increase (r m, finite rate of increase (λ, doubling time (DT and mean generation times (Tc. To obtain a better understanding of the biology of these biotypes, Stable age distribution (Cx and some other aspects of life history related to their hosts were also studied. Based upon the results, both biotypes showed a greater reproduction capacity on rapeseed than on cotton. Thus, rapeseed was more suitable host than cotton for two biotypes and this was an important factor in host plant selection for optimizing the control strategies of these major pests.

  4. Host Plant Effects on Alkaline Phosphatase Activity in the Whiteflies, Bemisia tabaci Biotype B and Trialeurodes vaporariorum

    Science.gov (United States)

    Yan, Ying; Peng, Lu; Liu, Wan-Xue; Wan, Fang-Hao; Harris, Marvin K.

    2011-01-01

    Bemisia tabaci (Gennadius) B-biotype and Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) often coexist on greenhouse-grown vegetable crops in northern China. The recent spread of B. tabaci B-biotype has largely replaced T. vaporariorum, and B-biotype now overlaps with T. vaporariorum where common hosts occur in most invaded areas. The impact of the B-biotype on the agro eco system appears to be widespread, and involves the ability to compete with and perhaps replace other phytophages like T. vaporariorum. An emerging hypothesis is that the B-biotype is physiologically superior due at least in part to an improved ability to metabolically utilize the alkaline phosphatase pathway. To test this hypothesis, alkaline phosphatase activity was studied in the B-biotype and T. vaporariorum after feeding on a number of different hosts for a range of durations, with and without host switching. Alkaline phosphatase activity in T. vaporariorum was 1.45 to 2.53-fold higher than that of the B-biotype when fed on tomato for 4 and 24 h, or switched from tomato to cotton and cabbage for the same durations. However, alkaline phosphatase activity in the B-biotype was 1.40 to 3.35-fold higher than that of T. vaporariorum when the host switching time was ∼72 and ∼120 h on the same plant. Both short-term (4 h) and long-term (72 h) switching of plant hosts can significantly affect the alkaline phosphatase activity in the two species. After ∼120 h, feeding on tomato and cotton alkaline phosphatase activity in the B-biotype was significantly higher than that of T. vaporariorum. It was shown that alkaline phosphatase aids the species feeding on different plant species, and that the B-biotype is physiologically superior to T. vaporariorum in utilizing the enzyme compared to T. vaporariorum over longer periods of feeding. PMID:21521136

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

    Directory of Open Access Journals (Sweden)

    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

  6. 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.

  7. 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 ...

  8. Whitefly (Bemisia tabaci) management program for ornamental plants

    Science.gov (United States)

    Bemisia tabaci (Gennadius) commonly known as silverleaf whitefly, is a polyphagous pest considered to be one of the most notorious invasive arthropods worldwide. The pest status of Bemisia tabaci is complicated because of their well debated taxonomic architecture which was previously identified to c...

  9. Effet des mouches blanches ( bemisia tabaci genn. ) Sur la ...

    African Journals Online (AJOL)

    A study was was carried out in order to contribute in the search of strategy of controlling Bemisia tabaci (Gennadius) devastator and responsible of the propagation and symptom severity Cassava mosaic disease (CMD) in cassava fields in Togo. In fact, it is the two combined actions of the whiteflies (B tabaci), waste on the ...

  10. 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.

  11. Comparative study of the five biological parameters of cotton whitefly Bemisia tabaci and silverleaf whitefly B. argentifolii bellows and perring reared on cotton under laboratory condition.

    Science.gov (United States)

    Samih, M A; Izadi, H; Mahdian, K

    2006-01-01

    The five biological parameters of sweetpotato whitefly, Bemisia tabaci (Genn.) and silverleaf whitefly Bemisia argentifolii Bellows and Perring (Hom: Aleyrodidae) as an important pest of cotton were compared on cotton in laboratory condition. The infested leaves containing nymphs and pupae were collected from cotton fields in Iran. Experiments were conducted in a growth chamber under 24+/-2 degrees C, 55+/-3% RH and 16:8 (L:D) photoperiod on cotton, Gossypium hirsutum L. The newly emerged populations of each species were released in to a large cage set on cotton plants, separately. In this investigation, total fecundity, oviposition period, adult's longevity, sex ratios and daily fertility rates of 50 mated females were calculated for each whitefly used 50 mated females for each treatment. The treatments included two whitefly species and one host plant i.e. Gossypium hirsutum L. (Varamin 76 variety). Emergence of adults and crawlers and percentages of females emerged from 100-200 eggs at four replications were also calculated. The results revealed that total fecundity, oviposition period, and developmental time for B. tabaci reared on gossipium were 65.25, 4.56, and 23.18, respectively and for B. argentifolii reared on gossipium were 97.06, 5.42, and 23.75, respectively. The results revealed that there are significant differences between parameter of total fecundity at 1%. Probability level and sex ratios at 5% probability level. No significant difference was found between oviposition period, developmental time and maximum adult's longevity at 5% probability level.

  12. Resistance mechanisms to chlorpyrifos and F392W mutation frequencies in the acetylcholine esterase ace1 allele of field populations of the tobacco whitefly, Bemisia tabaci in China.

    Science.gov (United States)

    Zhang, Ning-ning; Liu, Cai-feng; Yang, Fang; Dong, Shuang-lin; Han, Zhao-jun

    2012-01-01

    The tobacco whitefly B-biotype Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is a worldwide pest of many crops. In China, chlorpyrifos has been used to control this insect for many years and is still being used despite the fact that some resistance has been reported. To combat resistance and maintain good control efficiency of chlorpyrifos, it is essential to understand resistance mechanisms. A chlorpyrifos resistant tobacco whitefly strain (NJ-R) and a susceptible strain (NJ-S) were derived from a field-collected population in Nanjing, China, and the resistance mechanisms were investigated. More than 30-fold resistance was achieved after selected by chlorpyrifos for 13 generations in the laboratory. However, the resistance dropped significantly to about 18-fold in only 4 generations without selection pressure. Biochemical assays indicated that increased esterase activity was responsible for this resistance, while acetylcholine esterase, glutathione S-transferase, and microsomal-O-demethylase played little or no role. F392W mutations in acel were prevalent in NJ-S and NJ-R strains and 6 field-collected populations of both B and Q-biotype from locations that cover a wide geographical area of China. These findings provide important information about tobacco whitefly chlorpyrifos resistance mechanisms and guidance to combat resistance and optimize use patterns of chlorpyrifos and other organophosphate and carbamate insecticides.

  13. Biology of Bemisia tabaci (Genn. B-biotype and parasitism by Encarsia formosa (Gahan on collard, soybean and tomato plants Aspectos biológicos de Bemisia tabaci (Genn. biótipo B e parasitismo por Encarsia formosa (Gahan em couve, soja e tomateiro

    Directory of Open Access Journals (Sweden)

    Karina Manami Takahashi

    2008-12-01

    Full Text Available The silverleaf whitefly Bemisia tabaci (Genn. B-biotype (= B. argentifolii (Hemiptera: Aleyrodidae is a polyphagous insect attacking many plant species of economic importance. A comparison study was conducted on the duration of the egg-to-adult period, and the percentage of hatching eggs of Bemisia tabaci (Genn. B-biotype on collard (Brassica oleracea L. var. acephala D.C., soybean(Glycine max (L. Merr. and tomato (Lycopersicon esculentum Mill. plants, as well as the egg-to-adult period of Encarsia formosa (Gahan on the 1st, 2nd, 3rd and 4th whitefly nymphal instars on these three plant species. The experiments were conducted in a laboratory (25ºC, 70 ± 10% RH, 14-hour photophase. The duration of the egg-to-adult period of B. tabaci was 19.8 days on collard, 21.2 days on soybean and 22.0 days on tomato. The number of hatched eggs was higher on collard when compared to soybean and tomato plants. Concerning E. formosa regardless of plant species, the duration for the egg-to-adult period was shorter for the 3rd and 4th instar nymphs as compared with the other instars.A mosca branca Bemisia tabaci (Genn. biótipo B é uma praga polífaga que ataca muitas culturas de importância econômica. O controle químico pode causar problemas como o aparecimento de resistência nesse inseto, resíduos nos produtos das culturas, ou mesmo poluição ambiental. Um método alternativo seria o controle biológico, com o parasitóide Encarsia formosa (Gahan, o mais usado contra moscas brancas a nível mundial. Avaliaram-se o tempo de desenvolvimento de ovo a adulto e a porcentagem de ninfas eclodidas de B. tabaci (Genn. biótipo B em couve (Brassica oleracea L. var. acephala D.C., soja (Glycine max (L. Merr. e tomateiro (Lycopersicon esculentum Mill., bem como o desenvolvimento de ovo a adulto de E. formosa em ninfas de 1º, 2º, 3º e 4º ínstares dessa mosca-branca nessas três espécies vegetais. Os experimentos foram desenvolvidos em laboratório, a 25ºC, 70

  14. Monitoreo de estados inmaduros de la mosca blanca [Trialeurodes vaporariorum (Westwood) (Homoptera-Aleyrodidae)] reinfestando cultivo de tomate bajo invernadero en el período estival

    OpenAIRE

    Sánchez, Daniel E.; Scotta, Roberto R.; Arregui, María Cristina

    2002-01-01

    En los cultivos de tomate en invernadero, la mosca blanca de los invernaderos (Trialeurodes vaporariorum) se ha convertido en plaga clave, tanto por los daños que ocasiona, como por la dificultad para su control con métodos químicos. El objetivo de este trabajo fue determinar la distribución de los estados inmaduros de mosca blanca reinfestando la planta de tomate cultivada bajo invernadero, las áreas de concentración en el cultivo y detectar si existía en el período estival una relación entr...

  15. 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.

  16. 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

    Directory of Open Access Journals (Sweden)

    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

  17. Biology, ecology, and control of the Ficus whitefly, Singhiella simplex (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    The Ficus whitefly, Singhiella simplex (Singh) (Hemiptera: Aleyrodidae), is an economic pest of Ficus plant species in India, Burma and China. Severe infestations result in leaf dropping or shedding and defoliation. Since its initial US report in south Florida in 2007, the whitefly has expanded its ...

  18. Life table analysis and development of Singhiella simplex (Hemiptera:Aleyrodidae) under different constant temperatures

    Science.gov (United States)

    The ficus whitefly, Singhiella simplex (Singh) (Hemiptera: Aleyrodidae), is a newly-invasive pest of ficus plants in the United States. Very little is known about its biology and life history. Here, we studied development and reproduction at 15, 20, 25, 27, 30 and 35°C. No immatures survived the 35°...

  19. 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.

  20. Resistance to Bemisia tabaci in tomato wild relatives

    NARCIS (Netherlands)

    Firdaus, S.; Heusden, van A.W.; Hidayati, N.; Supena, E.D.J.; Visser, R.G.F.; Vosman, B.

    2012-01-01

    Bemisia tabaci is one of the most threatening pests in agriculture, particularly in Solanaceous crops such as tomato and pepper that are cultivated in the open field. Pesticide application is often not effective and hazardous to humans and environment. The exploitation of plant natural defenses that

  1. African ancestry of New World, Bemisia tabaci-whitefly species.

    Science.gov (United States)

    Mugerwa, Habibu; Seal, Susan; Wang, Hua-Ling; Patel, Mitulkumar V; Kabaalu, Richard; Omongo, Christopher A; Alicai, Titus; Tairo, Fred; Ndunguru, Joseph; Sseruwagi, Peter; Colvin, John

    2018-02-09

    Bemisia tabaci whitefly species are some of the world's most devastating agricultural pests and plant-virus disease vectors. Elucidation of the phylogenetic relationships in the group is the basis for understanding their evolution, biogeography, gene-functions and development of novel control technologies. We report here the discovery of five new Sub-Saharan Africa (SSA) B. tabaci putative species, using the partial mitochondrial cytochrome oxidase 1 gene: SSA9, SSA10, SSA11, SSA12 and SSA13. Two of them, SSA10 and SSA11 clustered with the New World species and shared 84.8‒86.5% sequence identities. SSA10 and SSA11 provide new evidence for a close evolutionary link between the Old and New World species. Re-analysis of the evolutionary history of B. tabaci species group indicates that the new African species (SSA10 and SSA11) diverged from the New World clade c. 25 million years ago. The new putative species enable us to: (i) re-evaluate current models of B. tabaci evolution, (ii) recognise increased diversity within this cryptic species group and (iii) re-estimate divergence dates in evolutionary time.

  2. Resistance Monitoring for Eight Insecticides on the Sweetpotato Whitefly (Hemiptera: Aleyrodidae) in China.

    Science.gov (United States)

    Wang, Shaoli; Zhang, Youjun; Yang, Xin; Xie, Wen; Wu, Qingjun

    2017-04-01

    The sweetpotato whitefly, Bemisia tabaci (Gennadius), is an important pest of many crops worldwide. Because control of B. tabaci still depends on the application of insecticides in China, monitoring the insecticide resistance of B. tabaci populations is essential for achieving control and for managing resistance. In this study, field populations of B. tabaci on vegetables were collected in three regions of China in 2011, 2012, and 2013. The resistance of these populations (all of which were determined to belong to biotype Q) to eight insecticides (abamectin, spinetoram, imidacloprid, thiamethoxam, acetamiprid, nitenpyram, chlorpyrifos, and bifenthrin) was assessed by the leaf-dip method. No resistance to abamectin and spinetoram was detected. All of the B. tabaci populations exhibited resistance to neonicotinoid insecticides; the resistance was 3.6- to 125.0-fold greater than that of a susceptible reference strain. The traditional insecticides chlorpyrifos and bifenthrin had very low toxicity. Bemisia tabaci specimens in some regions exhibited annual differences in resistance to some of the insecticides. The data presented will be helpful for making decisions on the proper insecticide usage in the field. © 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.

  3. Oogenesis in the Bemisia tabaci MEAM1 species complex.

    Science.gov (United States)

    Guo, Jian-Yang; Wan, Fang-Hao; Ye, Gong-Yin

    2016-04-01

    The whitefly Bemisia tabaci MEAM1 species complex has invaded several parts of the world in the past 30 years and replaced native whitefly populations in the invaded regions, including certain areas of China. One of the possible reasons for the invasion is that MEAM1 whiteflies are more fecund than native species. However, the factors that affect the reproduction of the B. tabaci cryptic species are not clearly known. The regulation of oogenesis is thought to be one of the essential processes for egg formation and ovary development and could affect its population dynamics. In this study, the ovariole structure and oogenesis of the MEAM1 species complex was examined using light and transmission electron microscopy. Telotrophic ovarioles were observed in the MEAM1 species complex. Each ovariole had two well defined regions: the tropharium and the vitellarium. The tropharium always had more than ten trophocytes. The development of a single oocyte in the vitellarium has four phases: oocyte formation, previtellogenesis, vitellogenesis and choriogenesis. Two arrested oocytes, follicular cells and uncompleted oocytes were separated from the tropharium by microtubule and microfilaments. Early previtellogenesis oocytes absorbed nutrients and endosymbiont bacteria through a nutritive cord. However, the vitellogenesis of oocytes transmitted Vg through both the nutritive cord and the space between follicular cells. Each mature oocyte with deposited yolk proteins had only one bacteriocyte and was surrounded by a single layer of follicular cells. The oogenesis in the B. tabaci MEAM1 species complex concluded with the differentiation of oocytes, the transport of yolk and endosymbionts as well as the development and maturation of oocytes. This result provides important information that further defines the regulation of oogenesis in the B. tabaci complex. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. 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).

  5. Quantitative resistance against Bemisia tabaci in Solanum pennellii : Genetics and metabolomics

    NARCIS (Netherlands)

    van den Oever-van den Elsen, Floor; Lucatti, Alejandro F.; van Heusden, Sjaak; Broekgaarden, Colette; Mumm, Roland; Dicke, Marcel; Vosman, Ben

    2016-01-01

    The whitefly Bemisia tabaci is a serious threat in tomato cultivation worldwide as all varieties grown today are highly susceptible to this devastating herbivorous insect. Many accessions of the tomato wild relative Solanum pennellii show a high resistance towards B. tabaci. A mapping approach was

  6. Genome sequencing of the sweet potato whitefly Bemisia tabaci MED/Q

    Science.gov (United States)

    Crypic and invasive species of whitefly, Bemisia tabaci, are highly destructive agricultural and ornamental crop pest that as a group cause direct feeding damage to host plants and vector a large number of harmful plant viruses. Introductions of B. tabaci are difficult to quarantine and eradicate d...

  7. Presencia de Clitostethus arcuatus (Coleoptera: Coccinellidae sobre olivos infestados con Siphoninus phillyreae (Hemiptera: Aleyrodidae en Argentina

    Directory of Open Access Journals (Sweden)

    María L. GASPARINI

    2007-01-01

    Full Text Available Se informa acerca del hallazgo de Clitostethus arcuatus (Rossi (Coleptera: Coccinellidae, Scymninae en plantas de olivo infestados con Siphoninus phillyreae (Haliday (Hemiptera: Aleyrodidae. El material se recolectó en plantaciones de olivo de los departamentos Junín, San Martín, Rivadavia y Maipú (Mendoza, Argentina durante los monitoreos de identificación de enemigos naturales de la «mosca blanca del fresno», Siphoninus phillyreae.

  8. Gadigaleyrodes froggatti, a new genus and species of whitefly (Hemiptera: Aleyrodidae) from Australia.

    Science.gov (United States)

    Dooley, John W; Gillespie, Peter

    2013-01-17

    A new monotypic genus of whiteflies (Aleyrodidae), Gadigaleyrodes gen.n., is described and illustrated for G. froggatti sp.n. from New South Wales, Australia. Specimens were collected by W. W. Froggatt in 1899 on Syncarpia glomulifera, and subsequently by P. S. Gillespie on an unknown climbing plant. The genus has unusual morphological features with traits common to both Aleurodicinae and Aleyrodinae. The subfamily placement is discussed, and a key provided to discriminate this taxon from similar whitefly genera in Australia.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. Monitoring changes in bemisia tabaci susceptibility to neonicotinoid insecticides in Arizona and California

    Science.gov (United States)

    Laboratory bioassays were carried out on field-collected and laboratory strains of Bemisia tabaci to evaluate relative toxicities of four neonicotinoid insecticides: acetamiprid, dinotefuran, imidacloprid and thiamethoxam. Susceptibility to all four neonicotinoids in leaf-uptake bioassays varied co...

  13. Tomato yellow leaf curl virus: No evidence for replication in the insect vector Bemisia tabaci.

    Science.gov (United States)

    Sánchez-Campos, Sonia; Rodríguez-Negrete, Edgar A; Cruzado, Lucía; Grande-Pérez, Ana; Bejarano, Eduardo R; Navas-Castillo, Jesús; Moriones, Enrique

    2016-08-01

    Begomovirus ssDNA plant virus (family Geminiviridae) replication within the Bemisia tabaci vector is controversial. Transovarial transmission, alteration to whitefly biology, or detection of viral transcripts in the vector are proposed as indirect evidence of replication of tomato yellow leaf curl virus (TYLCV). Recently, contrasting direct evidence has been reported regarding the capacity of TYLCV to replicate within individuals of B. tabaci based on quantitave PCR approaches. Time-course experiments to quantify complementary and virion sense viral nucleic acid accumulation within B. tabaci using a recently implemented two step qPCR procedure revealed that viral DNA quantities did not increase for time points up to 96 hours after acquisition of the virus. Our findings do not support a recent report claiming TYLCV replication in individuals of B. tabaci.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

  16. Inundative Field Releases and Evaluation of Three Predators for Bemisia tabasi (Hemiptera: Aleyrodidae) Management in Three Vegetable Crops

    Science.gov (United States)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a global pest on numerous crops, including vegetables. Weekly inundative releases of a coccinellid predator (Coccinella undecimpunctata L.), a mirid predator [Macrophillus caliginosus (Wagner)] and a neuropteran predator [Chrysoperla carnea S...

  17. Bacterial endosymbionts in field-collected samples of Trialeurodes sp. nr. abutiloneus (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Cass, Bodil N; Mozes-Daube, Netta; Iasur-Kruh, Lilach; Bondy, Elizabeth C; Kelly, Suzanne E; Hunter, Martha S; Zchori-Fein, Einat

    2014-01-01

    Facultative bacterial endosymbionts are common, influential associates of arthropods, yet their movement among host species has not been well documented. Plant-mediated transmission of Rickettsia has been shown for the whitefly Bemisia tabaci. Bemisia tabaci in USA cotton fields harbors the secondary symbionts Rickettsia and Hamiltonella, and co-occurs with Trialeurodes sp. nr. abutiloneus whiteflies. To determine whether symbionts may be shared, the microbial diversity of these whiteflies on cotton across the USA was analyzed. Trialeurodes sp. nr. abutiloneus bore Portiera, Pseudomonas, Serratia, Arsenophonus and Wolbachia. No Rickettsia or Hamiltonella were detected. These results provide no evidence for horizontal transmission of symbionts between these whitefly genera. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  18. Presencia de Clitostethus arcuatus (Coleoptera: Coccinellidae sobre olivos infestados con Siphoninus phillyreae (Hemiptera: Aleyrodidae en Argentina On the presence of Clitostethus arcuatus (Coleoptera: Coccinellidae on olive trees infested with Siphoninus phillyreae (Hemiptera: Aleyrodidae in Argentina

    Directory of Open Access Journals (Sweden)

    María L. Gasparini

    2007-07-01

    Full Text Available Se informa acerca del hallazgo de Clitostethus arcuatus (Rossi (Coleptera: Coccinellidae, Scymninae en plantas de olivo infestados con Siphoninus phillyreae (Haliday (Hemiptera: Aleyrodidae. El material se recolectó en plantaciones de olivo de los departamentos Junín, San Martín, Rivadavia y Maipú (Mendoza, Argentina durante los monitoreos de identificación de enemigos naturales de la «mosca blanca del fresno», Siphoninus phillyreae.The presence of Clitostethus arcuatus (Rossi (Coleoptera: Coccinellidae,Scymninae on olive trees infested with Siphoninus phillyreae (Haliday (Hemiptera: Aleyrodidae, is reported. Specimens were collected during a survey on natural enemies of «ash whitefly», Siphoninus phillyreae, carried out in olive plantations of Junín, San Martín, Rivadavia and Maipú (Mendoza, Argentina.

  19. Modelling the potential distribution of Bemisia tabaci in Europe in light of the climate change scenario.

    Science.gov (United States)

    Gilioli, Gianni; Pasquali, Sara; Parisi, Simone; Winter, Stephan

    2014-10-01

    Bemisia tabaci is a serious pest of agricultural and horticultural crops in greenhouses and fields around the world. This paper deals with the distribution of the pest under field conditions. In Europe, the insect is currently found in coastal regions of Mediterranean countries where it is subject to quarantine regulations. To assess the risk presented by B. tabaci to Europe, the area of potential establishment of this insect, in light of the climate change scenario, was assessed by a temperature-dependent physiologically based demographic model (PBDM). The simulated potential distribution under current climate conditions has been successfully validated with the available field records of B. tabaci in Europe. Considering climate change scenarios of +1 and +2 °C, range expansion by B. tabaci is predicted, particularly in Spain, France, Italy, Greece and along the Adriatic coast of the Balkans. Nonetheless, even under the scenario of +2 °C, northern European countries are not likely to be at risk of B. tabaci establishment because of climatic limitations. Model validation with field observations and evaluation of uncertainties associated with model parameter variability support the reliability of model results. The PBDM developed here can be applied to other organisms and offers significant advantages for assessing the potential distribution of invasive species. © 2014 Society of Chemical Industry.

  20. Homoptera: Aphididae

    African Journals Online (AJOL)

    Blackman and Eastop, ... types (i.e., red soil, brown soil, and black soil) in the area. Although all crops are attacked by a wide range ..... Sharp, J.C and Andrade, M. (1994). An investigation of the behavior of the pea aphid, Acyrthosiphon pisum.

  1. 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.

  2. Homoptera: Cicadidae

    African Journals Online (AJOL)

    1988-10-24

    dwelling bugs which make .... dimorphic, the males possessing a white band across the base of the abdomen which is lacking in the ... than 1,2 m, and the trees are at least 10 m in height, and also large stands of oak, pine, gum and.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Imidacloprid susceptibility survey and selection risk assessment in field populations of Nilaparvata lugens (Homoptera: Delphacidae).

    Science.gov (United States)

    Wang, Yan Hua; Gao, Cong Fen; Zhu, Yu Cheng; Chen, Jin; Li, Wen Hong; Zhuang, Yong Lin; Dai, De Jiang; Zhou, Wei Jun; Yong, Chong; Shen, Jin Liang

    2008-04-01

    Imidacloprid has been used for many years to control planthopper Nilaparvata lugens (Stål) (Homoptera: Delphacidae) in China. To provide resistance assessment for the national insecticide resistance management program, we collected a total of 42 samples of the planthoppers from 27 locations covering eight provinces to monitor their dose responses and susceptibility changes to imidacloprid over an 11-yr period (1996-2006). Results showed that most field populations maintained susceptibility from 1996 to 2003 except for a population from Guilin, Guangxi, in 1997, which showed a low level of resistance to imidacloprid. However, surveys conducted in 2005 indicated that 16 populations from six provinces quickly developed resistance with resistance ratios ranging from 79 to 811. The data collected in 2006 revealed that the resistance levels in 12 populations collected from seven different provinces decreased slightly (RR = 107-316), except the Tongzhou population (Jiangsu Province), which developed 625-fold resistance. Dominant and intensive use of imidacloprid in a wide range of rice, Oryza savita L., growing areas might be a driving force for the resistance development. Migration of the insect also significantly boosted the resistance levels due to extensive and intensive use of imidacloprid in emigrating areas and continuous postmigration sprays of the chemical. In addition, laboratory resistance selection using imidacloprid showed that resistance ratio increased to 14-fold after 27 generations, suggesting that quick resistance development might be associated with more frequent applications of the insecticide in recent years.

  5. 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.

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

    Science.gov (United States)

    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.

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

    OpenAIRE

    Macías-flores A; Santillán-Ortega C; Robles-Bermúdez A; Ortiz-Catón M; Cambero-Campos OJ

    2013-01-01

    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 acc...

  8. Complete Mitochondrial Genome of the Citrus Spiny Whitefly Aleurocanthus spiniferus (Quaintance) (Hemiptera: Aleyrodidae): Implications for the Phylogeny of Whiteflies.

    Science.gov (United States)

    Chen, Zhi-Teng; Mu, Li-Xia; Wang, Ji-Rui; Du, Yu-Zhou

    2016-01-01

    In this study, we sequenced the complete mitochondrial genome (15,220 bp) of the citrus spiny whitefly, Aleurocanthus spiniferus (Quaintance), a well-known pest from the superfamily Aleyrodidae. The A. spiniferus mitogenome contains 36 genes, including 13 protein-coding genes (PCGs), 21 transfer RNAs (tRNA), two ribosomal RNAs (rRNA) and a large non-coding region (control region, CR). Like most whiteflies, the A. spiniferus mitogenome had a large degree of rearrangement due to translocation of the nad3-trnG-cox3 gene cluster. The 13 PCGs initiated with ATN and generally terminated with TAA, although some used TAG or T as stop codons; atp6 showed the highest evolutionary rate, whereas cox2 appeared to have the lowest rate. The A. spiniferus mitogenome had 21 tRNAs with a typical cloverleaf secondary structure composed of four arms. Modeling of the two rRNA genes indicated that their secondary structure was similar to that of other insects. The CR of A. spiniferus was 920 bp and mapped between the nad3-trnG-cox3 and trnI-trnM gene clusters. One potential stem-loop structure and five tandem repeats were identified in the CR. Phylogenetic relationships of 11 species from the Aleyrodidae were analyzed based on the deduced amino acid sequences of the 13 PCGs and evolutionary characteristics were explored. Species with more genetic rearrangements were generally more evolved within the Aleyrodidae.

  9. Wolbachia Has Two Different Localization Patterns in Whitefly Bemisia tabaci AsiaII7 Species.

    Science.gov (United States)

    Shi, Peiqiong; He, Zhan; Li, Shaojian; An, Xuan; Lv, Ning; Ghanim, Murad; Cuthbertson, Andrew G S; Ren, Shun-Xiang; Qiu, Bao-Li

    2016-01-01

    The whitefly Bemisia tabaci is a cosmopolitan insect species complex that harbors the obligate primary symbiont Portiera aleyrodidarum and several facultative secondary symbionts including Wolbachia, which have diverse influences on the host biology. Here, for the first time, we revealed two different localization patterns of Wolbachia present in the immature and adult stages of B. tabaci AsiaII7 cryptic species. In the confined pattern, Wolbachia was restricted to the bacteriocytes, while in the scattered pattern Wolbachia localized in the bacteriocytes, haemolymph and other organs simultaneously. Our results further indicated that, the proportion of B. tabaci AsiaII7 individuals with scattered Wolbachia were significantly lower than that of confined Wolbachia, and the distribution patterns of Wolbachia were not associated with the developmental stage or sex of whitefly host. This study will provide a new insight into the various transmission routes of Wolbachia in different whitefly species.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    Moraiet Maher Ahmed; Ansari Mohammad Shafiq; Basri Rabiya

    2017-01-01

    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 Managemen...

  12. 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

    Directory of Open Access Journals (Sweden)

    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

  13. Natural history of whitefly in Costa Rica: an evolutionary starting point

    NARCIS (Netherlands)

    Burger, J.S.M.; Gort, G.; Van Lenteren, J.C.; Vet, L.E.M.

    2004-01-01

    To understand evolution of foraging behaviour in the whitefly parasitoid Encarsia formosa (Hymenoptera, Aphelinidae), natural densities and distributions of whitefly (Homoptera, Aleyrodidae) were quantified in E. formosa's presumed area of origin, the Neotropics. Leaves were collected in Costa Rican

  14. Natural history of whitefly in Costa Rica: an evolutionary starting point

    NARCIS (Netherlands)

    Burger, J.M.S.; Gort, G.; Lenteren, van J.C.; Vet, L.E.M.

    2004-01-01

    1. To understand evolution of foraging behaviour in the whitefly parasitoid Encarsia formosa (Hymenoptera, Aphelinidae), natural densities and distributions of whitefly (Homoptera, Aleyrodidae) were quantified in E. formosa's presumed area of origin, the Neotropics. 2. Leaves were collected in Costa

  15. 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

  16. Study of the pathosystem: Begomovirus Bemisia tabaci I tomato on the South West islands of the Indian Ocean

    NARCIS (Netherlands)

    Delatte, H.

    2005-01-01

    Tomato yellow leaf curl virus (TYLCV) belongs to the genus Begomovirus within the Geminiviridae family, and is exclusively transmitted by the whitefly species Bemisia labaci (Hemiptera: Aleyrodidae) (Gennadius). It is an emerging virus which since the 1980's has globally spread over many tropical,

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

    Science.gov (United States)

    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.

  18. Effect of dinotefuran 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...

  19. Efficacy of Eretmocerus eremicus and flupyradifurone on Bemisia tabaci (MED whitefly), 2017

    Science.gov (United States)

    Bemisia tabaci is a polyphagous pest known to feed on over 900 plant taxa, and is an effective vector of more than 100 plant damaging viruses. Among different biotypes of this cryptic species complex, Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED) whitefly are the two most destructive memb...

  20. Effect of Eretmocerus eremicus and soil application of cyantraniliprole on Bemisia tabaci (MED whitefly), 2016

    Science.gov (United States)

    Bemisia tabaci is a polyphagous pest known to feed on 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 to several crops of econ...

  1. Effect of foliar application of Xxpire on Bemisisa 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...

  2. Effect of soil application of cyantraniliprole 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...

  3. Impact of drench application of cyantraniliprole on Bemisia tabaci (MED whitefly) and Amblyseius swirskii, 2016

    Science.gov (United States)

    Bemisia tabaci is a polyphagous pest known to feed on 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 econ...

  4. Molecular and functional characterization of Bemisia tabaci aquaporins reveals the water channel diversity of hemipteran insects

    Science.gov (United States)

    The Middle East-Asia Minor 1 (MEAM1) whitefly, Bemisia tabaci (Gennadius) is an economically important pest of food, fiber, and ornamental crops. This pest has evolved a number of adaptations to overcome physiological challenges, including 1) the ability to regulate osmotic stress between gut lumen ...

  5. Efficacy of foliar application of flupyradifurone on Bemisia tabaci (MED whitefly) and Amblyseius swirskii, 2017

    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...

  6. Impact of pymetrozine on Bemisia tabaci (MED whitefly) and Amblyseius swirskii, 2017

    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, Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED) whitefly are the two most destructive me...

  7. 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...

  8. Effect of drench application of flupyradifurone on Bemisia tabaci(MED whitefly) and Amblyseius swirskii, 2017

    Science.gov (United States)

    Bemisia tabaci is a polyphagous pest known to feed on over 900 plant taxa, and is an effective vector of more than 100 plant damaging viruses. Among different biotypes of this cryptic species complex, Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED)whitefly are the two most destructive membe...

  9. Efficacy of Eretmocerus eremicus and cyantraniliprole on Bemisia tabaci (MED whitefly), 2017

    Science.gov (United States)

    Bemisia tabaci (Gennadius) feeds on more than 900 host plants and vectors over 111 plant virus species and is considered to be a major invasive species worldwide. Among different biotypes of this cryptic species complex, MEAM1 and MED whitefly are the two most destructive members posing threats to s...

  10. 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

  11. 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.

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

    Indian Academy of Sciences (India)

    [Upadhyay SK, Chandrashekar K, Thakur N, Verma PC, Borgio JF, Singh PK and Tuli R 2011 RNA interference for the control of whiteflies (Bemisia tabaci) by oral route. J. Biosci. 36 153–161] DOI 10.1007/s12038-011-9009-1. 1. Introduction. Cultivation of Bt-transgenic cotton has significantly reduced the usage of chemical ...

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

    Directory of Open Access Journals (Sweden)

    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

  14. Implication of Bemisia tabaci heat shock protein 70 in Begomovirus-whitefly interactions.

    Science.gov (United States)

    Götz, Monika; Popovski, Smadar; Kollenberg, Mario; Gorovits, Rena; Brown, Judith K; Cicero, Joseph M; Czosnek, Henryk; Winter, Stephan; Ghanim, Murad

    2012-12-01

    The whitefly Bemisia tabaci (Gennadius) is a major cosmopolitan pest capable of feeding on hundreds of plant species and transmits several major plant viruses. The most important and widespread viruses vectored by B. tabaci are in the genus Begomovirus, an unusual group of plant viruses owing to their small, single-stranded DNA genome and geminate particle morphology. B. tabaci transmits begomoviruses in a persistent circulative nonpropagative manner. Evidence suggests that the whitefly vector encounters deleterious effects following Tomato yellow leaf curl virus (TYLCV) ingestion and retention. However, little is known about the molecular and cellular basis underlying these coevolved begomovirus-whitefly interactions. To elucidate these interactions, we undertook a study using B. tabaci microarrays to specifically describe the responses of the transcriptomes of whole insects and dissected midguts following TYLCV acquisition and retention. Microarray, real-time PCR, and Western blot analyses indicated that B. tabaci heat shock protein 70 (HSP70) specifically responded to the presence of the monopartite TYLCV and the bipartite Squash leaf curl virus. Immunocapture PCR, protein coimmunoprecipitation, and virus overlay protein binding assays showed in vitro interaction between TYLCV and HSP70. Fluorescence in situ hybridization and immunolocalization showed colocalization of TYLCV and the bipartite Watermelon chlorotic stunt virus virions and HSP70 within midgut epithelial cells. Finally, membrane feeding of whiteflies with anti-HSP70 antibodies and TYLCV virions showed an increase in TYLCV transmission, suggesting an inhibitory role for HSP70 in virus transmission, a role that might be related to protection against begomoviruses while translocating in the whitefly.

  15. Effects of a foliar neem formulation on colonization and mortality of whiteflies (Hemiptera: Aleyrodidae) on collard plants

    Science.gov (United States)

    A study was conducted to determine the effects of foliar sprays of a selected neem (Azadirachta indica A. Juss) product (GOS Neem 7-Way) on colonization and development by the Middle-East Asia Minor-1 (= B-biotype sweetpotato whitefly) Bemisia tabaci (Gennadius) on collard (Brassica oleracea variety...

  16. Study of The Use Of Maize as Barrier Crop in Chili to Control Bemisia tabaci (Gennadius Population

    Directory of Open Access Journals (Sweden)

    Yogi Puspo Friarini

    2016-12-01

    Full Text Available This study was conducted to determine the effect of maize as barrier crop to prevent the spread of Bemisia tabaci (Gennadius, the yellow virus vector in pepper farming. The research was conducted in the field at Pakem, Sleman, during two cropping seasons from October 2014 to February 2015 as first planting period and in April to August 2015 as second planting period. The escalation of B. tabaci (Gennadius populations was directly correlated with virus yellow peppers increment. The result indicated that planting barrier was effective in reducing the spread of B. tabaci (Gennadius in pepper plants. The population of B. tabaci (Gennadius in plots with pepper surrounded by maize was lower compared to plots without maize barrier, showed that the yellow virus spreads on pepper can be minimized, and hence the incidence of yellow disease was also decreased.   INTISARI   Penelitian ini dilakukan untuk mengetahui pengaruh penanaman jagung sebagai pemberian tanaman pembatas (barrier untuk mengatasi penyebaran Bemisia tabaci (Gennadius yang merupakan vektor virus kuning pada tanaman cabai. Penelitian dilakukan di lahan pertanaman cabai di Pakem, Sleman. Penelitian dilaksanakan selama dua musim tanam dari bulan Oktober 2014 sampai dengan bulan Februari 2015 pada periode tanam I dan bulan April 2015 sampai dengan bulan Agustus 2015 pada periode tanam II. Meningkatnya populasi B. tabaci (Gennadius berbanding lurus dengan meningkatnya virus kuning pada cabai. Hasil penelitian ini menunjukkan bahwa penanaman tanaman pembatas (barrier cukup efektif mengurangi penyebaran B. tabaci (Gennadius pada ke dalam petak tanaman cabai. Populasi B. tabaci (Gennadius pada petak tanaman cabai yang dikelilingi tanaman jagung lebih rendah jika dibanding dengan petak tanaman cabai yang tidak dikelililing tanaman jagung, sehingga secara tidak langsung penyebaran virus kuning pada cabai dapat diminimalisir.

  17. Preliminary evaluation of Delphastus catalinae (Coleoptera:Coccinellidae)as a predator of the ficus whitefly, Singhiella simplex (Singh) (Hemiptera:Aleyrodidae)

    Science.gov (United States)

    The predatory lady beetle Delphastus catalinae (Horn) (Coleoptera: Coccinellidae) was evaluated as a potential biological control agent against the ficus whitefly, Singhiella simplex (Singh) (Hemiptera: Aleyrodidae), a newly-invasive pest of ficus plants. Adult D. catalinae females were starved for ...

  18. 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 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.

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

    Science.gov (United States)

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

    2014-07-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Global haplotype analysis of the whitefly Bemisia tabaci cryptic species Asia I in Asia.

    Science.gov (United States)

    Hu, Jian; Chen, Yong-Dui; Jiang, Zhi-Lin; Nardi, Francesco; Yang, Tai-Yuan; Jin, Jie; Zhang, Zhong-Kai

    2015-04-01

    The whitefly, Bemisia tabaci (Hemiptera: Aleyrodidiae), is a cryptic species complex comprising a minimum of 24 cryptic species. Some members of this complex are important agricultural pests, causing considerable damage to vegetable as well as ornamental and horticultural crops. Asia I, one of the cryptic species of B. tabaci, is widely distributed in Asia. One hundred and sixty mitochondrial cytochrome oxidase I (COI) sequences from eight countries have been analyzed to investigate the geographic origin and current genetic structure of this cryptic species. Sixty different haplotypes were identified, with levels of genetic distances ranging from 0.001 to 0.021. A sign of possible genetic differentiation emerges from the differential distribution of dominant haplotypes in Indonesia and India compared to China. A possible ancient separation between Asia I in India and Indonesia and secondary contact in China has been hypothesized.

  2. 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.

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

    Science.gov (United States)

    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

  4. Colonization of onions by endophytic fungi and their impacts on the biology of Thrips tabaci.

    Science.gov (United States)

    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.

  5. 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.

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

    Science.gov (United States)

    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.

  7. Methods for the Extraction of Endosymbionts from the Whitefly Bemisia tabaci.

    Science.gov (United States)

    Zhu, Dan-Tong; Wang, Xin-Ru; Ban, Fei-Xue; Zou, Chi; Liu, Shu-Sheng; Wang, Xiao-Wei

    2017-06-19

    Bacterial symbionts form an intimate relationship with their hosts and confer advantages to the hosts in most cases. Genomic information is critical to study the functions and evolution of bacterial symbionts in their host. As most symbionts cannot be cultured in vitro, methods to isolate an adequate quantity of bacteria for genome sequencing are very important. In the whitefly Bemisia tabaci, a number of endosymbionts have been identified and are predicted to be of importance in the development and reproduction of the pests through multiple approaches. However, the mechanism underpinning the associations remains largely unknown. The obstacle partially comes from the fact that the endosymbionts in whitefly, mostly restrained in bacteriocytes, are hard to separate from the host cells. Here we report a step-by-step protocol for the identification, extraction and purification of endosymbionts from the whitefly B. tabaci mainly by dissection and filtration. Endosymbiont samples prepared by this method, although still a mixture of different endosymbiont species, are suitable for subsequent genome sequencing and analysis of the possible roles of endosymbionts in B. tabaci. This method may also be used to isolate endosymbionts from other insects.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. A Bemisia tabaci midgut protein interacts with begomoviruses and plays a role in virus transmission.

    Science.gov (United States)

    Rana, Vipin Singh; Popli, Sonam; Saurav, Gunjan Kumar; Raina, Harpreet Singh; Chaubey, Rahul; Ramamurthy, V V; Rajagopal, R

    2016-05-01

    Begomoviruses are a major group of plant viruses, transmitted exclusively by Bemisia tabaci (Gennadius) in a persistent circulative non-propagative manner. The information regarding molecular and cellular basis underlying Begomovirus - whitefly interaction is very scarce. Evidences have suggested that the insect gut possesses some crucial protein receptors that allow specific entry of virus into the insect haemolymph. We have performed yeast two hybrid gut cDNA expression library screening against coat protein of Tomato leaf curl New Delhi virus (ToLCV) and Cotton leaf curl Rajasthan virus (CLCuV) as bait. Midgut protein (MGP) was the common protein found interacting with both ToLCV and CLCuV. MGP was localized in whole mount B. tabaci as well as in dissected guts through confocal microscopy. Pull down and dot blot assays confirmed in vitro interaction between ToLCV/CLCuV coat protein and MGP. Immunolocalization analysis also showed colocalization of ToLCV/CLCuV particles and MGP within insect's gut. Finally, anti-MGP antibody fed B. tabaci, exhibited 70% reduction in ToLCV transmission, suggesting a supportive role for MGP in virus transmission. © 2015 John Wiley & Sons Ltd.

  10. 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)

  11. Transcriptome changes occurred in the whitefly, B. tabaci MEAM1 in response to feeding on melon infected with the crinivirus, CYSDV

    Science.gov (United States)

    CYSDV, a crinivirus transmitted by the whitefly, B. tabaci, causes widespread losses in melon and other cucurbits. The virus emerged in the southwestern United States in 2006. It established in crops and weeds, and is transmitted to cucurbits by the resident population of B. tabaci MEAM1 each year. ...

  12. Characterization of Paecilomycescinnamomeus from the camellia whitefly, Aleurocanthus camelliae (Hemiptera: Aleyrodidae), infesting tea in Japan.

    Science.gov (United States)

    Saito, Tsutomu; Takatsuka, Jun; Shimazu, Mitsuaki

    2012-05-01

    The whitefly, Aleurocanthus camelliae Kanmiya and Kasai (Hemiptera: Aleyrodidae), is an invasive species in Japan that was first discovered in 2004 on tea in Kyoto. Soon after its arrival epizootics of an entomopathogenic fungus were observed in populations of the whitefly in many tea-growing regions. Here we identify this fungus as Paecilomyces cinnamomeus (Petch) Samson and W. Gams (Hypocreales: Clavicipitaceae) based on morphological characteristics and molecular analyses. This is the first record of P. cinnamomeus in Japan and also the first time it has been recorded from the genus Aleurocanthus. A isolate of P. cinnamomeus caused greater than 50% and 90% infection in whitefly nymphs at 1×10(6) and 1×10(7)conidia/ml respectively, while the commercial mycoinsecticides Preferd® (Isaria fumosorosea) and Mycotal® (Lecanicillium muscarium) caused <10% infection at their recommended field rates (5×10(6) and 9×10(6)conidia/ml, respectively), suggesting that P. cinnamomeus may be more useful as a control agent than the currently available mycoinsecticides. Optimum and upper limit temperatures for in vitro growth of P. cinnamomeus isolates were 22.5-25°C and 32.5°C, respectively. At field rates, the fungicide thiophanate-methyl caused some inhibition of in vitro growth of P. cinnamomeus isolates, and the bactericide copper oxychloride and the insecticides tolfenpyrad and methidathion were strongly inhibitory. The findings obtained in this study will be useful in the development of microbial control programs using P. cinnamomeus against A. camelliae. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Ecology and management of the woolly whitefly (Hemiptera: Aleyrodidae), a new invasive citrus pest in Ethiopia.

    Science.gov (United States)

    Belay, Difabachew K; Zewdu, Abebe; Foster, John E

    2011-08-01

    Distribution and importance of woolly whitefly (Aleurothrixus floccosus) (Maskell) (Hemiptera: Aleyrodidae), was studied in Ethiopia with an evaluation of treatments against it. Results showed that the pest is distributed in most citrus-growing parts of the country equally infesting all types of citrus crops. Only one pupal parasitoid, Amitus sp., was recorded at Melkaoba. During 2006-2007, eight treatments gave better control of woolly whitefly compared with the control: endod (Phytolacca dodecandra L'Herit) berry extract, white oil 80%, neem oil, omo detergent soap, band application of gasoline, cyhalothrin (karate) 5% EC, selecron (profenofos) 500 EC, and rimon (novaluron) 10 EC. Treatments were applied on 6-8 yr-old orange trees at Melkaoba and Nazareth. At Melkaoba, application of cyhalothrin, selecron, white oil, and Neem gave better control of woolly whitefly compared with the control. All the treatments resulted in a lower number of ants than the control. Ants disrupt biocontrol agents of honeydew-secreting pests, including woolly whiteflies. Mean infestation score was higher in the control than the rest of the treatments. Similarly, at Nazareth, woolly whitefly numbers were lower recorded on cyhalothrin-treated plants. However, the numbers of eggs were significantly higher in endod extract-sprayed plants than the control. All treatments controlled ants better than the control except endod. Infestation scores were lower on endod- and cyhalothrin-treated plants than the control. Mean number of adult woolly whiteflies and eggs were significantly higher on newly grown leaves than older leaves. In general, the number of live adult woolly whiteflies showed a decreasing trend at both sites after treatment applications compared with the control.

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

    Directory of Open Access Journals (Sweden)

    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

  15. 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.

  16. Olfactory response of predatory Macrolophus caliginosus Wagner (Heteroptera: Miridae) to the odours host plant infested by Bemisia tabaci

    Science.gov (United States)

    Saad, Khalid A.; Roff, M. N. Mohamad; Salam, Mansour; Hanifah Mohd, Y.; Idris, A. B.

    2014-09-01

    Plant infested with herbivores, release volatile that can be used by natural enemies to locate their herbivorous prey. Laboratory studies were carried out to determine the olfactory responses of predator Macrolophus caliginosus Wagner (Heteroptera: Miridae), to chili plant infected with eggs, nymphs of Bemisia tabaci, using Y-tube olfactometer. The results shown that predator, M. caliginosus has ability to discriminate between non-infested and infested plant by B. tabaci. Moreover, the predator preferred plants with nymphs over plants with eggs. This suggested that M. caliginous uses whitefly-induced volatile as reliable indicators to distinguish between infested chili plants by nymphs, eggs and non-infested plants. These results enhance our understanding of the olfactory cues that guide foraging by M. caliginosus to plant with and without Bemisia tabaci.

  17. HUBUNGAN KUTU DOMPOLAN DYSMICOCCUS BREVIPES (CKLL. (HOMOPTERA : PSEUDOCOCCIDAE DAN SEMUT API SOLENOPSIS SP. (HYMENOPTERA: FORMICIDAE PADA DUA CARA BERTANAM NENAS

    Directory of Open Access Journals (Sweden)

    Rosma Hasibuan .

    2012-02-01

    Full Text Available Association of mealybug, Dysmicoccus brevipes (Ckll. (Homoptera: Pseudococcidae and fire ant, Solenopsis sp. (Hymenoptera: Formicidae on two pineapple–planting patterns.  A pineapple mealybug, Dysmicoccus  brevipes (Ckll.  (Homoptera: Pseudococcidae is an important insect pest in major pineapple growing areas.  Its feeding activity causes damage on the pineapple plants and it can also transmit pineapple wilt virus.  The mealybugs are often found in association with fire ants, Solenopsis sp. (Hymenoptera: Formicidae that provide protection in exchange for the sweet honeydew liquid. The field study was conducted to determine the close association between  mealybugs and fire ants on  two plant row spacing (single and double row spacing four different plant stages (3, 7, 11, and 17 months after planting. The  results indicated  that there was a significant correlation between the mealybugs and the fire ant on two pineapple-planting patterns, particularly on late growth periods (11, and 17 months after planting. In this field study, population of mealybugs on double row spacing were more abundant  (ranging from 0 to 25.67 bugs/plant compared with that on single row spacing which ranged 0 to 3.67 bugs/plant. Moreover, general mean of population density of mealybugs (14.53 bugs/plant on double row was significantly higher  than that on single row spacing (1.83 bugs/plant. In  line with this mealybug-population development, mean numbers of fire ants caught on baited-sticky traps were ranged from 0 to 8.53 ants/trap on single row versus 0 to 23.57 ants/trap on double row spacing pattern. The general mean number of captured ants (12.73 ants/trap on double row was significantly higher compared with that on single row spacing (5.55 ants/trap. It appears that the patterns of population densities of mealybugs are closely related to that of fire ants that act as attendant species on two pineapple row spacing.

  18. Effect of plant development (age and size) on the Mi-1-mediated resistance of tomato to whitefly Bemisia tabaci.

    Science.gov (United States)

    Rodríguez-Álvarez, C I; Muñiz, M; Nombela, G

    2017-12-01

    Whitefly, Bemisia tabaci, is one of the most important pests of tomato, Solanum lycopersicum L. The Mi-1 gene mediates tomato resistance to the Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED) species of B. tabaci, three species of root-knot nematodes, Meloidogyne spp., and the potato aphid, Macrosiphum euphorbiae. Tomato seedlings bearing the Mi-1 gene are resistant to nematodes soon after germination but resistance to aphids is developmentally regulated; a reliable conclusion about Mi-1 resistance to B. tabaci was not available to date. In the present work, 3-, 5- and 8-week-old plants of the tomato cultivars Motelle and Moneymaker (bearing and lacking the Mi-1 gene, respectively) were simultaneously tested under free-choice (antixenosis) and no-choice (antibiosis) conditions, to assess the real influence of plant age on the Mi-1-mediated resistance to the MED species of B. tabaci. Subsequently, plants of the same age but with different level of development were compared to check whether the plant size can also affect this tomato resistance. Obtained results demonstrated that Mi-1-mediated resistance to B. tabaci is developmentally regulated, as variations in the age of bearing-Mi-1 plants affects most infestation parameters tested. Differences between cultivars with and without the Mi-1 gene were significant for 8- but not for 3-week-old plants. For 5-week-old plants, differences between cultivars were less pronounced than in older plants, expressing an intermediate level of resistance in Motelle. Plant size also influenced whitefly infestation and reproductive activity on the resistant cultivar. However, plant age has more impact than plant size on the Mi-1-mediated resistance of tomato to B. tabaci.

  19. Phylogenetic Relationships among Whiteflies in the Bemisia tabaci (Gennadius Species Complex from Major Cassava Growing Areas in Kenya

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    Duke M. Manani

    2017-02-01

    Full Text Available Whiteflies, Bemisia tabaci (Gennadius are major insect pests that affect many crops such as cassava, tomato, beans, cotton, cucurbits, potato, sweet potato, and ornamental crops. Bemisia tabaci transmits viral diseases, namely cassava mosaic and cassava brown streak diseases, which are the main constraints to cassava production, causing huge losses to many small-scale farmers. The aim of this work was to determine the phylogenetic relationships among Bemisia tabaci species in major cassava growing areas of Kenya. Surveys were carried out between 2013 and 2015 in major cassava growing areas (Western, Nyanza, Eastern, and Coast regions, for cassava mosaic disease (CMD and cassava brown streak disease (CBSD. Mitochondrial cytochrome oxidase I (mtCOI-DNA was used to determine the genetic diversity of B. tabaci. Phylogenetic trees were constructed using Bayesian methods to understand the genetic diversity across the study regions. Phylogenetic analysis revealed two B. tabaci species present in Kenya, sub-Saharan Africa 1 and 2 comprising five distinct clades (A–E with percent sequence similarity ranging from 97.7 % to 99.5%. Clades B, C, D, and E are predominantly distributed in the Western and Nyanza regions of Kenya whereas clade B is dominantly found along the coast, the eastern region, and parts of Nyanza. Our B. tabaci clade A groups with sub-Saharan Africa 2-(SSA2 recorded a percent sequence similarity of 99.5%. In this study, we also report the identification of SSA2 after a 15 year absence in Kenya. The SSA2 species associated with CMD has been found in the Western region of Kenya bordering Uganda. More information is needed to determine if these species are differentially involved in the epidemiology of the cassava viruses.

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

    Directory of Open Access Journals (Sweden)

    Francisco Clemilto da Silva Maciel

    2011-12-01

    Full Text Available The Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae is an important pest of citrus. Originated in Asia, this pest was detected in Brazil for the first time in the State of Para, Brazil in 2001. In the culture of citrus fruits the black fly carries direct and indirect damage, impeding the development and production of plants. In addition to restricting trade in local areas from its occurrence to the presence of the plague, since the A. woglumi quarantine pest is considered present (A2 of high alert in accordance with Instruction No 23, April 29, 2008, established by the Ministério da Agricultura, Pecuária e Abastecimento of the Brazil. The objective of this paper was to record the first occurrence of Aleurocanthus woglumi in the State of Roraima, Brazil.= A mosca-negra-dos-citros, Aleurocanthus woglumi Ashb, (Hemiptera: Aleyrodidae é uma importante praga dos citros. De origem asiática, esta praga foi detectada no Brasil pela primeira vez no estado do Pará no ano de 2001. Na cultura dos citros a mosca-negra acarreta danos diretos e indiretos, prejudicando o desenvolvimento e produção das plantas. Além de restringir o comércio de locais de sua ocorrência para áreas livres da presença da praga, visto que o A. woglumi é considerado praga quarentenária presente (A2 de alerta máximo de acordo com a instrução normativa No 23, de 29 de abril de 2008; estabelecida pelo Ministério da Agricultura, Pecuária e Abastecimento. Objetivou-se com o presente trabalho registrar a primeira ocorrência de mosca-negra-dos-citros no estado de Roraima.

  1. 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

  2. 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...

  3. Resistance of tomato genotypes to the greenhouse whitefly Trialeurodes vaporariorum (West.) (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Lucatti, Alejandro F; Alvarez, Adriana E; Machado, Cristina R; Gilardón, Elsa

    2010-01-01

    The greenhouse whitefly, Trialeurodes vaporariorum Westwood, is the most common and abundant whitefly in Argentine horticultural greenhouse crops, especially in tomato (Solanum lycopersicum). Resistance in some wild tomato relatives, such as S. peruvianum, S. habrochaites and S. pennellii to the greenhouse whitefly has been described. The Mi gene confers effective resistance against several species of insects, among them the sweet potato whitefly, Bemisia tabaci Gennadius. Resistance to T. vaporariorum was found in the prebreeding line FCN 93-6-2, derived from a cross between S. lycopersicum cultivar Uco Plata INTA (MiMi) and the wild line FCN 3-5 S. habrochaites. The purpose of this study was to evaluate resistance to T. vaporariorum in tomato genotypes and to study the relationship between this resistance and the presence of the REX-1 marker, which is linked to the Mi gene. In a free-choice assay, the average number of adults per leaf and the number of immatures on the middle and basal plant parts were analyzed. In a no-choice assay, the oviposition rate and adult survival rate were calculated. For all variables analyzed, FCN 3-5 was the most resistant strain. Variations were found in the F2 progeny between the prebreeding line FCN 13-1-6-1 and cv. Uco Plata INTA. Results from the F2 progeny indicate that resistance to T. vaporariorum may be polygenic with transgressive segregation. Whitefly resistance was found to be independent of the REX-1 marker.

  4. Microsatellite-based analysis of the genetic structure and diversity of Aleurocanthus spiniferus (Hemiptera: Aleyrodidae) from tea plants in China.

    Science.gov (United States)

    Tang, Xiao-Tian; Tao, Huan-Huan; Du, Yu-Zhou

    2015-04-10

    Although Aleurocanthus spiniferus (Quaintance) (Hemiptera: Aleyrodidae) is a well known insect pest of tea plants, little information is available about its genetic structure and diversity. The present study used microsatellite markers to assess the genetic structure and diversity of this species on tea plants in China. For this purpose, 193 individuals from ten natural populations were analyzed using ten microsatellite markers. Our results indicated that the average number of alleles (A) across populations was 35.6, and all observed heterozygosities (HO) were greater than 0.7, indicating an excess of heterozygosity and a relatively high level of genetic diversity among populations, and the number of private alleles per population ranged from 3 to 26. Pairwise FST analysis suggested that the number of genetic differentiation events was moderate (0.05Bottleneck test indicated that most populations had experienced a population bottleneck. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Functional characteristics of a tiny but specialized olfactory system: olfactory receptor neurons of carrot psyllids (Homoptera: Triozidae).

    Science.gov (United States)

    Kristoffersen, Lina; Larsson, Mattias C; Anderbrant, Olle

    2008-11-01

    With only approximately 50 olfactory receptor neurons (ORNs), the carrot psyllid Trioza apicalis (Homoptera: Psylloidea) may have the smallest olfactory system described in adult Neopteran insects. Using single sensillum recordings (SSR) and gas chromatograph-linked SSR, we characterized 4 olfactory sensilla forming a distinct morphological type, which together house approximately 25% of all ORNs. We recorded responses to extracts and single constituents from Daucus carota ssp. sativus, from the conifers Picea abies, Pinus sylvestris, and Juniperus communis, as well as from male and female T. apicalis. Receptor neurons were highly selective; only 9 compounds in total elicited repeatable responses, and each neuron responded to at most 3 individual compounds. Chemical profiles of carrot and conifers showed significant overlap, with 4 out of 9 electrophysiologically active compounds occurring in more than one type of extract, but a carrot-specific compound elicited the most repeated responses. We identified 4 tentative neuron classes and found a rather high degree of neuronal redundancy, with 1 neuron class present in 3 and another present in all 4 of the sensilla, respectively.

  6. The Cuticle Protein Gene MPCP4 of Myzus persicae (Homoptera: Aphididae) Plays a Critical Role in Cucumber Mosaic Virus Acquisition.

    Science.gov (United States)

    Liang, Yan; Gao, Xi-Wu

    2017-06-01

    Myzus persicae (Sulzer) (Homoptera: Aphididae) is one of the most important agricultural pests worldwide. In addition to sucking phloem sap, M. persicae also transmits Cucumber mosaic virus (CMV) as a vector in a nonpersistent manner. At present, the infection mechanism remains unclear, especially the process of aphid virus acquisition. In this study, we isolated four M. persicae cuticle protein genes (MPCP1, MPCP2, MPCP4, and MPCP5) from M. persicae. The relative amount of the gene encoding Cucumber mosaic virus capsid protein (CMV CP) and the transcript levels of these four cuticle protein genes were investigated in aphid virus acquisition by feeding the tobacco preinfested by CMV. The relative expression of MPCP1, MPCP2, and MPCP4 were significantly higher than MPCP5 at 24 h after aphids feeding on virus-infested tobacco. Yeast two-hybrid assays demonstrated that the protein encoded by MPCP4 gene was closely associated with the CMV CP through the direct interaction. Moreover, the ability of M. persicae to acquire CMV was suppressed by RNA interference of MPCP4. All these lines of evidence indicate that MPCP4, as a viral putative receptor in the stylet of aphid, plays an important role in aphid acquisition of CMV. © 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.

  7. Reaction of Indicator Tobacco Cultivars to Races of Pseudomonas syringaepv. tabaciTox+

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    Cole DL

    2014-12-01

    Full Text Available Three races of Pseudomonas syringaepv. tabaciTox+ (wildfire (races 0, 1 and 2 and two races of Tox- (angular leaf spot (races 1 and 2 have been confirmed on tobacco in Zimbabwe (Zim. Very few cultivars with no resistance to Ps. syringaepv. tabaci are grown commercially and race 0 has not been isolated since 1996. Because we no longer have a viable culture of race 0, we obtained an isolate of race 0 from Kentucky (0 KY, USA in January 2000. We included this isolate in race tests on standard indicator cultivars K E1 (susceptible to all races, KM 10 (resistance to race 0 derived from Nicotianalongiflora, WZ (resistance to races 0 and 1 derived from N. rustica and a hybrid, K 35 (resistance to races 0 and 0 and 1 derived from N. longiflora and N. rustica respectively. Two leaves on 10-week-old seedlings were inoculated with a bacterial suspension (106 colony forming units [cfu] per mL by spraying selected areas until just watersoaked and incubating the plants at 28 C and 70% RH for 10 d. The reaction to race 0, measured as lesion diameter, was different from that previously obtained with race 0 (Zim. Races 0 and 1 (Zim are avirulent on WZ but race 0 (KY was virulent. Further isolates of race 0 were received from Maryland (MD and Tennessee (TN. The TN isolates overcame resistance derived from N. longiflora and N. rustica, except where both sets of genes were present in the same cultivar. Reactions have been variable with the race 0 (MD isolate suggesting it is a mixed culture. We conclude that there are at least four races of Ps. syringaepv. tabaciTox+ worldwide and race 0 (KY should be designated race 3. On all cultivars, race 2 consistently caused the largest lesions.

  8. Small RNAs from Bemisia tabaci Are Transferred to Solanum lycopersicum Phloem during Feeding

    Science.gov (United States)

    van Kleeff, Paula J. M.; Galland, Marc; Schuurink, Robert C.; Bleeker, Petra M.

    2016-01-01

    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. PMID:27933079

  9. Genome reduction and potential metabolic complementation of the dual endosymbionts in the whitefly Bemisia tabaci.

    Science.gov (United States)

    Rao, Qiong; Rollat-Farnier, Pierre-Antoine; Zhu, Dan-Tong; Santos-Garcia, Diego; Silva, Francisco J; Moya, Andrés; Latorre, Amparo; Klein, Cecilia C; Vavre, Fabrice; Sagot, Marie-France; Liu, Shu-Sheng; Mouton, Laurence; Wang, Xiao-Wei

    2015-03-21

    The whitefly Bemisia tabaci is an important agricultural pest with global distribution. This phloem-sap feeder harbors a primary symbiont, "Candidatus Portiera aleyrodidarum", which compensates for the deficient nutritional composition of its food sources, and a variety of secondary symbionts. Interestingly, all of these secondary symbionts are found in co-localization with the primary symbiont within the same bacteriocytes, which should favor the evolution of strong interactions between symbionts. In this paper, we analyzed the genome sequences of the primary symbiont Portiera and of the secondary symbiont Hamiltonella in the B. tabaci Mediterranean (MED) species in order to gain insight into the metabolic role of each symbiont in the biology of their host. The genome sequences of the uncultured symbionts Portiera and Hamiltonella were obtained from one single bacteriocyte of MED B. tabaci. As already reported, the genome of Portiera is highly reduced (357 kb), but has kept a number of genes encoding most essential amino-acids and carotenoids. On the other hand, Portiera lacks almost all the genes involved in the synthesis of vitamins and cofactors. Moreover, some pathways are incomplete, notably those involved in the synthesis of some essential amino-acids. Interestingly, the genome of Hamiltonella revealed that this secondary symbiont can not only provide vitamins and cofactors, but also complete the missing steps of some of the pathways of Portiera. In addition, some critical amino-acid biosynthetic genes are missing in the two symbiotic genomes, but analysis of whitefly transcriptome suggests that the missing steps may be performed by the whitefly itself or its microbiota. These data suggest that Portiera and Hamiltonella are not only complementary but could also be mutually dependent to provide a full complement of nutrients to their host. Altogether, these results illustrate how functional redundancies can lead to gene losses in the genomes of the different

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  12. Incidence of white fly (Bemisia tabaci Genn.) and their sustainable management by using biopesticides

    OpenAIRE

    GHOSH, SUNIL

    2014-01-01

    Ladysfinger (Abelmoschus esculentus L.) (Moench) is susceptible to various pests of which white fly (Bemisia tabaci Genn.) causes heavy damage. The pest was active throughout the growing period with a peak population (3.98 white fly /leaf) and (4.33 /leaf) during 20rd SMW (middle of May) in the pre-kharif crop and during 42nd -43rd SMW (middle of October) in the post kharif crop respectively. Sudden fall of population was found during July because of heavy rains. White fly showed non-signific...

  13. Conservation of natural enemies in cotton: comparative selectivity of acetamiprid in the management of Bemisia tabaci.

    Science.gov (United States)

    Naranjo, Steven E; Akey, David H

    2005-06-01

    The integrated control concept emphasizes the importance of both chemical and biological control for pest suppression in agricultural systems. A two-year field study was conducted to evaluate the selectivity of acetamiprid for the control of Bemisia tabaci (Gennadius) in cotton compared with a proven selective regime based on the insect growth regulators (IGRs) pyriproxyfen and buprofezin. Acetamiprid was highly effective in controlling all stages of B tabaci compared with an untreated control, and generally produced lower pest densities than the IGR regime. Univariate analyses indicated that nine of 17 taxa of arthropod predators were significantly depressed with the use of acetamiprid compared with an untreated control, including common species such as Geocoris punctipes (Say), Orius tristicolor (White), Chrysoperla carnea Stephens sensu lato, Collops vittatus (Say), Hippodamia convergens Guérin-Méneville, and Drapetis nr divergens. Compared with results from independent, concurrent studies using mixtures of broad-spectrum insecticides at the same research site, acetamiprid depressed populations of fewer predator taxa; but, for eight predator taxa significantly affected by both regimes, the average population reduction was roughly equal. In contrast, only four taxa were significantly reduced in the IGR regime compared with the untreated control and three of these were omnivores that function primarily as plant pests. Principal response curves analyses (a time-dependent, multivariate ordination method) confirmed these patterns of population change for the entire predator community. Predator:prey ratios generally increased with the use of both IGRs and acetamiprid compared with an untreated control, but ratios were consistently higher with IGRs. Parasitism by aphelinid parasitoids was unaffected or depressed slightly in all insecticide regimes compared with the control. Because of its high efficacy, acetamiprid may play an important role in later stages of B

  14. Combinación de diferentes estrategias de aplicación de hongos entomopatógenos para el control de Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) y Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae)

    OpenAIRE

    Resquín Romero, Gloria Arminda

    2016-01-01

    Los ascomicetos mitospóricos entomopatógenos, que actúan por vía tegumentaria, han sido utilizados para el control microbiano de plagas mediante distintas estrategias que permiten el contacto de sus conidios con los insectos diana. Sin embargo, se conocen nuevos aspectos sobre su función ecológica tales como su capacidad secretora de compuestos con actividad insecticida, así como su sorprendente comportamiento como endófitos, que complementan su empleo clásico y que pueden pantag ermitir e...

  15. Elevated O3 and TYLCV Infection Reduce the Suitability of Tomato as a Host for the Whitefly Bemisia tabaci

    Science.gov (United States)

    Cui, Hongying; Sun, Yucheng; Chen, Fajun; Zhang, Youjun; Ge, Feng

    2016-01-01

    The effects of elevated atmospheric ozone (O3) levels on herbivorous insects have been well studied, but little is known about the combined effects of elevated O3 and virus infection on herbivorous insect performance. Using open-top chambers in the field, we determined the effects of elevated O3 and Tomato yellow leaf curl virus (TYLCV) infection on wild-type (Wt) tomato and 35S tomato (jasmonic acid (JA) defense-enhanced genotype) in association with whitefly, Bemisia tabaci Gennadius biotype B. Elevated O3 and TYLCV infection, alone and in combination, significantly reduced the contents of soluble sugars and free amino acids, increased the contents of total phenolics and condensed tannins, and increased salicylic acid (SA) content and the expression of SA-related genes in leaves. The JA signaling pathway was upregulated by elevated O3, but downregulated by TYLCV infection and O3 + TYLCV infection. Regardless of plant genotype, elevated O3, TYLCV infection, or O3 + TYLCV infection significantly decreased B. tabaci fecundity and abundance. These results suggest that elevated O3 and TYLCV infection, alone and in combination, reduce the nutrients available for B. tabaci, increase SA content and SA-related gene expression, and increase secondary metabolites, resulting in decreases in fecundity and abundance of B. tabaci in both tomato genotypes. PMID:27916792

  16. 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

  17. Single basal application of thiacloprid for the integrated management of Meloidogyne incognita and Bemisia tabaci in tomato crops

    Science.gov (United States)

    Dong, Sa; Ren, Xiaofen; Zhang, Dianli; Ji, Xiaoxue; Wang, Kaiyun; Qiao, Kang

    2017-01-01

    Tomato growers commonly face heavy nematode (Meloidogyne incognita) and whitefly (B-biotype Bemisia tabaci) infestations, and previous studies demonstrated that thiacloprid could be used to control M. incognita and B. tabaci in cucumber. However, the efficacy of a single basal application of thiacloprid to control both pests and its effect on yield in tomato remains unknown. In this study, the potential of thiacloprid application to the soil for the integrated control of M. incognita and B. tabaci in tomato was evaluated in the laboratory and the field. Laboratory tests showed that thiacloprid was highly toxic to whitefly adults and eggs with an average lethal concentration 50 (LC50) of 14.7 and 62.2 mg ai L-1, respectively, and the LC50 of thiacloprid for nematode J2s and eggs averaged 36.2 and 70.4 mg ai L-1, respectively. In field trials, when thiacloprid was applied to the soil at 7.5, 15 and 30 kg ha-1 in two consecutive years, whitefly adults decreased by 37.8-75.4% within 60 days of treatment, and the root-galling index was reduced by 31.8-85.2%. Optimum tomato plant growth and maximum yields were observed in the 15 kg ha-1 treatment. The results indicated that a single basal application of thiacloprid could control M. incognita and B. tabaci and enhance tomato growth and yield.

  18. RNA Interference based Approach to Down Regulate Osmoregulators of Whitefly (Bemisia tabaci): Potential Technology for the Control of Whitefly

    Science.gov (United States)

    Raza, Amir; Malik, Hassan Jamil; Shafiq, Muhammad; Amin, Imran; Scheffler, Jodi A.; Scheffler, Brian E.; Mansoor, Shahid

    2016-01-01

    Over the past decade RNA interference (RNAi) technology has emerged as a successful tool not only for functional genomics, but in planta expression of short interfering RNAs (siRNAs) that could offer great potential for insect pest management. The diet of insects feeding exclusively on phloem sieves contains water and sugars as main components, and the uptake of the liquid food greatly depends on the osmotic pressure within the insect body. Based on this physiological mechanism, transgenic plants of Nicotiana tabacum were generated expressing double stranded RNA (dsRNA) against both aquaporin (AQP) and a sucrase gene, alpha glucosidase (AGLU). These two genes are involved in osmotic pressure maintenance particularly in sap sucking insects, and the aim was to disrupt osmoregulation within the insect ultimately leading to mortality. Real time quantitative PCR (RT-qPCR) was performed to assess the suppression of gene expression in Bemisia tabaci (B. tabaci) and mortality was recorded during transgenic tobacco feeding bioassays. Feeding of insects on plants expressing dsRNA significantly reduced the transcript level of the target genes in B. tabaci after six days of feeding and more than 70% mortality was observed in B. tabaci fed on transgenic plants compared to the control plants. Our data shows that down-regulation of genes related to osmoregulation may find practical applications for the control of this important pest in cotton and other crops. PMID:27105353

  19. RNA Interference based Approach to Down Regulate Osmoregulators of Whitefly (Bemisia tabaci: Potential Technology for the Control of Whitefly.

    Directory of Open Access Journals (Sweden)

    Amir Raza

    Full Text Available Over the past decade RNA interference (RNAi technology has emerged as a successful tool not only for functional genomics, but in planta expression of short interfering RNAs (siRNAs that could offer great potential for insect pest management. The diet of insects feeding exclusively on phloem sieves contains water and sugars as main components, and the uptake of the liquid food greatly depends on the osmotic pressure within the insect body. Based on this physiological mechanism, transgenic plants of Nicotiana tabacum were generated expressing double stranded RNA (dsRNA against both aquaporin (AQP and a sucrase gene, alpha glucosidase (AGLU. These two genes are involved in osmotic pressure maintenance particularly in sap sucking insects, and the aim was to disrupt osmoregulation within the insect ultimately leading to mortality. Real time quantitative PCR (RT-qPCR was performed to assess the suppression of gene expression in Bemisia tabaci (B. tabaci and mortality was recorded during transgenic tobacco feeding bioassays. Feeding of insects on plants expressing dsRNA significantly reduced the transcript level of the target genes in B. tabaci after six days of feeding and more than 70% mortality was observed in B. tabaci fed on transgenic plants compared to the control plants. Our data shows that down-regulation of genes related to osmoregulation may find practical applications for the control of this important pest in cotton and other crops.

  20. Elevated O3 and TYLCV Infection Reduce the Suitability of Tomato as a Host for the Whitefly Bemisia tabaci

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    Hongying Cui

    2016-11-01

    Full Text Available The effects of elevated atmospheric ozone (O3 levels on herbivorous insects have been well studied, but little is known about the combined effects of elevated O3 and virus infection on herbivorous insect performance. Using open-top chambers in the field, we determined the effects of elevated O3 and Tomato yellow leaf curl virus (TYLCV infection on wild-type (Wt tomato and 35S tomato (jasmonic acid (JA defense-enhanced genotype in association with whitefly, Bemisia tabaci Gennadius biotype B. Elevated O3 and TYLCV infection, alone and in combination, significantly reduced the contents of soluble sugars and free amino acids, increased the contents of total phenolics and condensed tannins, and increased salicylic acid (SA content and the expression of SA-related genes in leaves. The JA signaling pathway was upregulated by elevated O3, but downregulated by TYLCV infection and O3 + TYLCV infection. Regardless of plant genotype, elevated O3, TYLCV infection, or O3 + TYLCV infection significantly decreased B. tabaci fecundity and abundance. These results suggest that elevated O3 and TYLCV infection, alone and in combination, reduce the nutrients available for B. tabaci, increase SA content and SA-related gene expression, and increase secondary metabolites, resulting in decreases in fecundity and abundance of B. tabaci in both tomato genotypes.

  1. 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

  2. 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

  3. Thrips tabaci (Thysanoptera: Thripidae) and Iris yellow spot virus associated with onion transplants, onion volunteers, and weeds in Colorado

    Science.gov (United States)

    Thrips tabaci infestation was determined on onion transplants received in Colorado during March and April from out of state sources (Imperial Valley, near Phoenix Arizona, and southern Texas) during 2004 to 2008. In the five years of the study, 50% to 100% of the transplant lots sampled were found ...

  4. Evaluation de la sensibilité à Bemisia tabaci (Gen) de 13 variétés de ...

    African Journals Online (AJOL)

    Evaluation de la sensibilité à Bemisia tabaci (Gen) de 13 variétés de tomate ( Lycopersicon esculentum Mill.) et expression des symptômes de la jaunisse en cuillère des feuilles (TYLCV) en Côte d\\'Ivoire.

  5. Arabidopsis thaliana plants with different levels of aliphatic- and indolyl-glucosinolates affect host selection and performance of Bemisia tabaci.

    Science.gov (United States)

    Markovich, Oshry; Kafle, Dinesh; Elbaz, Moshe; Malitsky, Sergey; Aharoni, Asaph; Schwarzkopf, Alexander; Gershenzon, Jonathan; Morin, Shai

    2013-12-01

    Generalist insects show reduced selectivity when subjected to similar, but not identical, host plant chemical signatures. Here, we produced transgenic Arabidopsis thaliana plants that over-express genes regulating the aliphatic- and indolyl- glucosinolates biosynthetic pathways with either a constitutive (CaMV 35S) or a phloem-specific promoter (AtSUC2). This allowed us to examine how exposure to high levels of aliphatic- or indolyl-glucosinolates in homogenous habitats (leaf cage apparatus containing two wild-type or two transgenic leaves) and heterogeneous habitats (leaf cage apparatus containing one wild-type and one transgenic leaf) affects host selection and performance of Bemsia tabaci, a generalist phloem-feeding insect. Data from homogenous habitats indicated that exposure to A. thaliana plants accumulating high levels of aliphatic- or indolyl-glucosinolates negatively affected the performance of both adult females and nymphs of B. tabaci. Data from heterogeneous habitats indicated that B. tabaci adult females selected for oviposition plants on which their offspring perform better (preference-performance relationship). However, the combinations of wild-type and transgenic plants in heterogeneous habitats increased the period of time until the first choice was made and led to increased movement rate on transgenic plants, and reduced fecundity on wild-type plants. Overall, our findings are consistent with the view that both performance and selectivity of B. tabaci decrease in heterogeneous habitats that contain plants with closely-related chemical signatures.

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

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    Jean-Michel Lett

    2012-12-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Aspectos biológicos de Coccidophilus citricola (Coleoptera, Coccinellidae sobre Aspidiotus nerii e Chrysomphalus aonidum (Homoptera, Diaspididae Biological studies of Coccidophilus citricola (Coleoptera, Coccinellidae on Aspidiotus nerii and Chrysomphalus aonidum (Homoptera, Diaspididae

    Directory of Open Access Journals (Sweden)

    Antonio Cesar dos Santos

    2005-02-01

    Full Text Available Aspectos biológicos de Coccidophilus citricola Brèthes (Coleoptera, Coccinellidae foram estudados sobre Chrysomphalus aonidum Linnaeus e Aspidiotus nerii Bouchè (Homoptera, Diaspididae criadas sobre abóbora. Observou-se a duraç��o (dias do período de ovo, dos quatro ínstares, pré-pupa, pupa, longevidade de adultos e a proporção machos: fêmeas de C. citricola. Determinou-se também verificar a eficiência de predação de adultos de C. citricola sobre A. nerii. C. aonidum e A. nerii são presas adequadas para C. citricola, com desenvolvimento semelhante do coccinelídeo sobre essas cochonilhas; o período de incubação do ovo foi de 7,9 e 8,1 dias com A. nerii e C. aonidum; a duração (dias de cada ínstar larval de C. citricola sobre A. nerii e C. aonidum foram respectivamente de: (I 2,7 e 2,9; (II 3,1 e 3,3; (III 3,0 e 3,3 e (IV 3,2 e 3,1 dias. A duração das fases de pré-pupa e pupa foi de 2,5 e 4,5 dias sobre A. nerii e 2,8 e 4,8 dias sobre C. aonidum e a viabilidade de ovo a adulto foi de 63,2% e 62,7% respectivamente para indivíduos criados sobre essas presas. A longevidade de adultos de C. citricola foi de 57,0 dias com A. nerii e de 62,0 dias com C. aonidum. A proporção macho: fêmea foi de 0,82:1,00. O consumo diário de C. citricola foi de 1,15 adultos ou 2,35 ninfas de 2o ínstar ou 3,16 ninfas de 1o ínstar de A. nerii por dia.Laboratory trials were carried out to study biological aspects of Coccidophilus citricola Brèthes (Coleoptera: Coccinellidae on Chrysomphalus aonidum Linnaeus and Aspidiotus nerii Bouché (Homoptera: Diaspididae. The scales were reared on squashes and then served as food source to the predator. The period of egg, larvae (four ínstars, pre-pupae, pupae, adults’ longevity and male: female ratio was observed. Predatory efficacy of C. citricola on A. nerii was also determined. The period of egg was 7.9 and 8.1 days on A. nerii and C. aonidum. The development (days of different stages of C

  10. Onion thrips, Thrips tabaci, have gut bacteria that are closely related to the symbionts of the western flower thrips, Frankliniella occidentalis.

    Science.gov (United States)

    de Vries, Egbert J; van der Wurff, André W G; Jacobs, Gerrit; Breeuwer, Johannes A J

    2008-01-01

    It has been shown that many insects have Enterobacteriaceae bacteria in their gut system. The western flower thrips, Frankliniella occidentalis Pergande [Thysanoptera: Thripidae], has a symbiotic relation with Erwinia species gut bacteria. To determine if other Thripidae species have similar bacterial symbionts, the onion thrips, Thrips tabaci, was studied because, like F. occidentalis, it is phytophagous. Contrary to F. occidentalis, T. tabaci is endemic in Europe and biotypes have been described. Bacteria were isolated from the majority of populations and biotypes of T. tabaci examined. Bacteria were present in high numbers in most individuals of the populations studied. Like F. occidentalis, T. tabaci contained one type of bacterium that clearly outnumbered all other types present in the gut. This bacterium was identified as an Erwinia species, as was also the case for F. occidentalis. However, its biochemical characteristics and 16S rDNA sequence differed from the bacteria present in F. occidentalis.

  11. 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.

  12. 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

    Directory of Open Access Journals (Sweden)

    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

  13. 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

    Directory of Open Access Journals (Sweden)

    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

  14. 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...

  15. 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.

  16. Effects of operational and environmental factors on evolution of resistance to pyriproxyfen in the sweetpotato whitefly (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Crowder, David W; Ellsworth, Peter C; Tabashnik, Bruce E; Carriére, Yves

    2008-12-01

    Pyriproxyfen has been an important insecticide used as part of an integrated pest management (IPM) program for the sweetpotato whitefly, Bemisia tabaci (Gennadius) (B biotype), in Arizona cotton. We used a simulation model to examine the effects of pyriproxyfen concentration, insecticide action thresholds, crop diversity, planting date, and pyriproxyfen decay on evolution of resistance to pyriproxyfen in B. tabaci. In the model, pyriproxyfen use was restricted to cotton with a limit of one application per season. Other model parameters were based on data from laboratory and field experiments. Whitefly population densities and the number of insecticide applications per year increased as resistance evolved. Resistance evolved slowest with a low pyriproxyfen concentration. Lower action thresholds for pyriproxyfen and higher action thresholds for insecticides other than pyriproxyfen also slowed the evolution of resistance. However, lower action thresholds for pyriproxyfen resulted in more insecticide sprays per year with a high pyriproxyfen concentration. Resistance to pyriproxyfen evolved fastest in cotton-intensive regions and slowest in multicrop regions. In regions with noncotton crops, increasing immigration to cotton slowed resistance. Resistance evolved faster with earlier planting dates, although fewer insecticide sprays were needed compared with fields planted later in the year. Faster rates of pyriproxyfen decay slowed resistance. In some cases, strategies that delayed resistance were effective from an IPM perspective. However, some strategies that delayed resistance resulted in higher population densities. Results suggest that modification of operational and environmental factors, which can be controlled by growers, could prolong the efficacy of pyriproxyfen.

  17. Transmission of Pantoea ananatis and P. agglomerans, causal agents of center rot of onion (Allium cepa), by onion thrips (Thrips tabaci) through feces.

    Science.gov (United States)

    Dutta, B; Barman, A K; Srinivasan, R; Avci, U; Ullman, D E; Langston, D B; Gitaitis, R D

    2014-08-01

    Frankliniella fusca, the tobacco thrips, has been shown to acquire and transmit Pantoea ananatis, one of the causal agents of the center rot of onion. Although Thrips tabaci, the onion thrips, is a common pest of onions, its role as a vector of P. ananatis has been unknown. The bacterium, P. agglomerans, is also associated with the center rot of onion, but its transmission by thrips has not been previously investigated. In this study, we investigated the relationship of T. tabaci with P. ananatis and P. agglomerans. Surface-sterilized T. tabaci were provided with various acquisition access periods (AAP) on onion leaves inoculated with either P. ananatis or P. agglomerans. A positive exponential relationship was observed between thrips AAP duration and P. ananatis (R² = 0.967; P = 0.023) or P. agglomerans acquisition (R² = 0.958; P = 0.017). Transmission experiments conducted with T. tabaci adults indicated that 70% of the seedlings developed center rot symptoms 15 days after inoculation. Immunofluorescence microscopy with antibodies specific to P. ananatis revealed that the bacterium was localized only in the gut of T. tabaci adults. Mechanical inoculation of onion seedlings with fecal rinsates alone produced center rot but not with salivary secretions. Together these results suggested that T. tabaci could efficiently transmit P. ananatis and P. agglomerans.

  18. 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

  19. Effect of starvation on vein preference of whitefly (Bemisia tabaci) on chilli as host plant

    Science.gov (United States)

    Siti Sakinah, A.; Mohamad Roff M., N.; Idris, A. B.

    2014-09-01

    The whitefly, Bemisia tabaci (Gennadius), is a cosmopolitan pest of horticultural crops. It caused serious damaged to the plants by feeding on plant saps as direct damage and transmit virus as indirect damage. Vein preferences of both female and male whitefly (WF) on chilli plant were recorded using Dinolite, a portable microscope, under laboratory conditions. WF adults of both sexes were starved for 2 and 4 hours before used for observation while no starvation for control individual (treatment). Results showed that both female and male preferred to feed on secondary veins rather than lamina, midrib and vein. From the result of whitefly preferred target site, hopefully this information will help to improve control tactics in WF management.

  20. Molecular characterization of soluble and membrane-bound trehalases of the whitefly, Bemisia tabaci.

    Science.gov (United States)

    Wang, Jia; He, Wen-Bo; Su, Yun-Lin; Bing, Xiao-Li; Liu, Shu-Sheng

    2014-04-01

    Trehalases (Tres) have been demonstrated to be the key enzymes that are involved in various trehalose-associated physiological processes in insects. However, little attention has been devoted to the Tres in the whitefly, Bemisia tabaci. In this study, a soluble Tre (BtTre-1) and a membrane-bound Tre (BtTre-2) were cloned in the invasive cryptic species Middle East-Asia Minor 1 (MEAM1) of the whitefly B. tabaci complex. Alignment of deduced amino acids sequences of both BtTres revealed that they share common consensus regions and residues with Tres of other insect species. Levels of BtTres expression in various stages and tissues of the whitefly suggested that BtTre-2 may play a key role in trehalose catabolism during development of the whitefly, especially for oocyte development, while BtTre-1 may prevent trehalose in salivary gland from leaking and entering into plants along with saliva. Potential roles of trehalose catabolism in response to direct and/or plant-mediated indirect effects of Tomato Yellow Leaf Curl China Virus (TYLCCNV) were also detected. Whiteflies feeding on virus-infected tobacco plants showed higher BtTres expressions and accordingly higher BtTres activity but lower trehalose content than those feeding on uninfected plants. The enhanced trehalose catabolism may be beneficial to oocyte development in ovary and attenuate plant defensive responses induced by trehalose in saliva. Viruliferous and nonviruliferous whiteflies feeding on cotton, a nonhost plant for TYLCCNV, differed significantly only in trehalose content. The higher trehalose content in viruliferous whiteflies may be conducive to resisting the stress inflicted by TYLCCNV. © 2014 Wiley Periodicals, Inc.

  1. Comparative antifeedant activities of polygodial and pyrethrins against whiteflies (Bemisia tabaci) and aphids (Myzus persicae).

    Science.gov (United States)

    Prota, Neli; Bouwmeester, Harro J; Jongsma, Maarten A

    2014-04-01

    Polygodial, a sesquiterpene dialdehyde of the drimane family, has been shown to have deterrent and antifeedant effects on various insect species, including Myzus persicae (Sulzer), Spodoptera spp. and Leptinotarsa decemlineata (Say). This compound may have potential as a broad-spectrum biocontrol agent, similar to pyrethrins, given that it was previously reported to improve yield when sprayed on barley fields. This study compares the deterrent effect of polygodial and pyrethrins against the silverleaf whitefly Bemisia tabaci (Gennadius) and the green peach aphid M. persicae in dual-choice assays using compound-coated tomato leaf discs. B. tabaci adults were deterred by polygodial at an ED50 (effective dose at which 50% of the insects are deterred) of about 25 µg g(-1) fresh weight (FW), and green peach aphids at about 54 µg g(-1) FW. Bioassays were benchmarked with pyrethrins that had a 20-fold lower ED50 of approximately 1.4 µg g(-1) FW against whiteflies, but only a twofold lower ED50 (about 28 µg g(-1) FW) against peach aphids. Polygodial showed moderate phytotoxic effects (score of 2 on a scale of 1-5) on tomato leaves at concentrations above the ED50 concentrations (≥ 90 µg g(-1) FW). The sesquiterpene dialdehyde polygodial is 2-20 times less deterrent than pyrethrins, depending on the insect species, but it could provide a useful complement to pyrethrin sprays as it has a different mode of action, is food grade and has low volatility. However, a formulation that reduces the risks of phytotoxic effects should be developed. © 2013 Society of Chemical Industry.

  2. Preferência de Bemisia tabaci biótipo B para oviposição em cultivares de algodoeiro Preference of Bemisia tabaci biotype B oviposition in cotton cultivars

    Directory of Open Access Journals (Sweden)

    Luciana Cláudia Toscano

    2003-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a preferência de Bemisia tabaci biótipo B para oviposição em cultivares de algodoeiro. Em teste com chance de escolha, a cultivar Deltapine Acala 90, pilosa, foi a mais preferida para oviposição (6,11 ovos/cm² de folha em relação a Antares, glabra, (0,49 ovos/cm² de folha. A preferência para oviposição da mosca-branca não foi influenciada pelas cultivares em teste sem chance de escolha. Considerando o índice de preferência para oviposição, a cultivar Deltapine Acala 90 foi classificada como estimulante, e Antares como deterrente, demonstrando resistência do tipo não-preferência para oviposição a B. tabaci biótipo B.The objective of this work was to evaluate the oviposition preference to Bemisia tabaci biotype B in cotton cultivars. In free choice test, Deltapine Acala 90, pilose cultivar, was the most preferred for oviposition (6.11 eggs/cm² of leaf in relation to Antares, smooth leaf, (0.49 eggs/cm² of leaf. The oviposition preference of whitefly was not influenced by cultivars in no-choice test. The oviposition preference index classified Deltapine Acala 90 as stimulant, while Antares was classified as deterrent to insect oviposition, showing oviposition non-preference type to B. tabaci biotype B

  3. A geographic distribution database of the Neotropical cassava whitefly complex (Hemiptera, Aleyrodidae) and their associated parasitoids and hyperparasitoids (Hymenoptera).

    Science.gov (United States)

    Vásquez-Ordóñez, Aymer Andrés; Hazzi, Nicolas A; Escobar-Prieto, David; Paz-Jojoa, Dario; Parsa, Soroush

    2015-01-01

    Whiteflies (Hemiptera, Aleyrodidae) are represented by more than 1,500 herbivorous species around the world. Some of them are notorious pests of cassava (Manihot esculenta), a primary food crop in the tropics. Particularly destructive is a complex of Neotropical cassava whiteflies whose distribution remains restricted to their native range. Despite their importance, neither their distribution, nor that of their associated parasitoids, is well documented. This paper therefore reports observational and specimen-based occurrence records of Neotropical cassava whiteflies and their associated parasitoids and hyperparasitoids. The dataset consists of 1,311 distribution records documented by the International Center for Tropical Agriculture (CIAT) between 1975 and 2012. The specimens are held at CIAT's Arthropod Reference Collection (CIATARC, Cali, Colombia). Eleven species of whiteflies, 14 species of parasitoids and one species of hyperparasitoids are reported. Approximately 66% of the whitefly records belong to Aleurotrachelus socialis and 16% to Bemisia tuberculata. The parasitoids with most records are Encarsia hispida, Amitus macgowni and Encarsia bellottii for Aleurotrachelus socialis; and Encarsia sophia for Bemisia tuberculata. The complete dataset is available in Darwin Core Archive format via the Global Biodiversity Information Facility (GBIF).

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

    Science.gov (United States)

    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.

  5. 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

    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...... appeared on weeds (the common ragweed and piemarker) about 10 days earlier than on cotton, or the other cultivated plants. The peak population densities were observed over a span of two to three weeks on cotton, starting in early (2010) or mid- (2011) August. The common ragweed growing adjacent to cotton...... increase the population density of B. tabaci MED on cotton, while sunflower could act as a trap crop for decreasing pest pressure on cotton....

  6. Role of the Insect Supervectors Bemisia tabaci and Frankliniella occidentalis in the Emergence and Global Spread of Plant Viruses.

    Science.gov (United States)

    Gilbertson, Robert L; Batuman, Ozgur; Webster, Craig G; Adkins, Scott

    2015-11-01

    Emergence of insect-transmitted plant viruses over the past 10-20 years has been disproportionately driven by two so-called supervectors: the whitefly, Bemisia tabaci, and the Western flower thrips, Frankliniella occidentalis. High rates of reproduction and dispersal, extreme polyphagy, and development of insecticide resistance, together with human activities, have made these insects global pests. These supervectors transmit a diversity of plant viruses by different mechanisms and mediate virus emergence through local evolution, host shifts, mixed infections, and global spread. Associated virus evolution involves reassortment, recombination, and component capture. Emergence of B. tabaci-transmitted geminiviruses (begomoviruses), ipomoviruses, and torradoviruses has led to global disease outbreaks as well as multiple paradigm shifts. Similarly, F. occidentalis has mediated tospovirus host shifts and global dissemination and the emergence of pollen-transmitted ilarviruses. The plant virus-supervector interaction offers exciting opportunities for basic research and global implementation of generalized disease management strategies to reduce economic and environmental impacts.

  7. Arsenophonus GroEL interacts with CLCuV and is localized in midgut and salivary gland of whitefly B. tabaci.

    Science.gov (United States)

    Rana, Vipin Singh; Singh, Shalini Thakur; Priya, Natarajan Gayatri; Kumar, Jitendra; Rajagopal, Raman

    2012-01-01

    Cotton leaf curl virus (CLCuV) (Gemininiviridae: Begomovirus) is the causative agent of leaf curl disease in cotton plants (Gossypium hirsutum). CLCuV is exclusively transmitted by the whitefly species B. tabaci (Gennadius) (Hemiptera: Alerodidae). B. tabaci contains several biotypes which harbor dissimilar bacterial endo-symbiotic community. It is reported that these bacterial endosymbionts produce a 63 kDa chaperon GroEL protein which binds to geminivirus particles and protects them from rapid degradation in gut and haemolymph. In biotype B, GroEL protein of Hamiltonella has been shown to interact with Tomato yellow leaf curl virus (TYLCV). The present study was initiated to find out whether endosymbionts of B. tabaci are similarly involved in CLCuV transmission in Sriganganagar (Rajasthan), an area endemic with cotton leaf curl disease. Biotype and endosymbiont diversity of B. tabaci were identified using MtCO1 and 16S rDNA genes respectively. Analysis of our results indicated that the collected B. tabaci population belong to AsiaII genetic group and harbor the primary endosymbiont Portiera and the secondary endosymbiont Arsenophonus. The GroEL proteins of Portiera and Arsenophonus were purified and in-vitro interaction studies were carried out using pull down and co-immunoprecipitation assays. In-vivo interaction was confirmed using yeast two hybrid system. In both in-vitro and in-vivo studies, the GroEL protein of Arsenophonus was found to be interacting with the CLCuV coat protein. Further, we also localized the presence of Arsenophonus in the salivary glands and the midgut of B. tabaci besides the already reported bacteriocytes. These results suggest the involvement of Arsenophonus in the transmission of CLCuV in AsiaII genetic group of B. tabaci.

  8. Arsenophonus GroEL interacts with CLCuV and is localized in midgut and salivary gland of whitefly B. tabaci.

    Directory of Open Access Journals (Sweden)

    Vipin Singh Rana

    Full Text Available Cotton leaf curl virus (CLCuV (Gemininiviridae: Begomovirus is the causative agent of leaf curl disease in cotton plants (Gossypium hirsutum. CLCuV is exclusively transmitted by the whitefly species B. tabaci (Gennadius (Hemiptera: Alerodidae. B. tabaci contains several biotypes which harbor dissimilar bacterial endo-symbiotic community. It is reported that these bacterial endosymbionts produce a 63 kDa chaperon GroEL protein which binds to geminivirus particles and protects them from rapid degradation in gut and haemolymph. In biotype B, GroEL protein of Hamiltonella has been shown to interact with Tomato yellow leaf curl virus (TYLCV. The present study was initiated to find out whether endosymbionts of B. tabaci are similarly involved in CLCuV transmission in Sriganganagar (Rajasthan, an area endemic with cotton leaf curl disease. Biotype and endosymbiont diversity of B. tabaci were identified using MtCO1 and 16S rDNA genes respectively. Analysis of our results indicated that the collected B. tabaci population belong to AsiaII genetic group and harbor the primary endosymbiont Portiera and the secondary endosymbiont Arsenophonus. The GroEL proteins of Portiera and Arsenophonus were purified and in-vitro interaction studies were carried out using pull down and co-immunoprecipitation assays. In-vivo interaction was confirmed using yeast two hybrid system. In both in-vitro and in-vivo studies, the GroEL protein of Arsenophonus was found to be interacting with the CLCuV coat protein. Further, we also localized the presence of Arsenophonus in the salivary glands and the midgut of B. tabaci besides the already reported bacteriocytes. These results suggest the involvement of Arsenophonus in the transmission of CLCuV in AsiaII genetic group of B. tabaci.

  9. 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

  10. Assessment of Potential Sublethal Effects of Various Insecticides on Key Biological Traits of The Tobacco Whitefly, Bemisia tabaci

    Science.gov (United States)

    He, Yuxian; Zhao, Jianwei; Zheng, Yu; Weng, Qiyong; Biondi, Antonio; Desneux, Nicolas; Wu, Kongming

    2013-01-01

    The tobacco whitefly Bemisia tabaci is one of the most devastating pests worldwide. Current management of B. tabaci relies upon the frequent applications of insecticides. In addition to direct mortality by typical acute toxicity (lethal effect), insecticides may also impair various key biological traits of the exposed insects through physiological and behavioral sublethal effects. Identifying and characterizing such effects could be crucial for understanding the global effects of insecticides on the pest and therefore for optimizing its management in the crops. We assessed the effects of sublethal and low-lethal concentrations of four widely used insecticides on the fecundity, honeydew excretion and feeding behavior of B. tabaci adults. The probing activity of the whiteflies feeding on treated cotton seedlings was recorded by an Electrical Penetration Graph (EPG). The results showed that imidacloprid and bifenthrin caused a reduction in phloem feeding even at sublethal concentrations. In addition, the honeydew excretions and fecundity levels of adults feeding on leaf discs treated with these concentrations were significantly lower than the untreated ones. While, sublethal concentrations of chlorpyrifos and carbosulfan did not affect feeding behavior, honeydew excretion and fecundity of the whitefly. We demonstrated an antifeedant effect of the imidacloprid and bifenthrin on B. tabaci, whereas behavioral changes in adults feeding on leaves treated with chlorpyrifos and carbosulfan were more likely caused by the direct effects of the insecticides on the insects' nervous system itself. Our results show that aside from the lethal effect, the sublethal concentration of imidacloprid and bifenthrin impairs the phloem feeding, i.e. the most important feeding trait in a plant protection perspective. Indeed, this antifeedant property would give these insecticides potential to control insect pests indirectly. Therefore, the behavioral effects of sublethal concentrations of

  11. Evaluation de la sensibilité à Bemisia tabaci (Gen) de 13 variétés de ...

    African Journals Online (AJOL)

    L\\'étude a été conduite,de janvier à juin 2003, au Centre de la Côte d\\'Ivoire. Elle a eu pour but d\\'évaluer au 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 feuilles de tomate («Tomato yellow leaf curl virus» : TYLCV).

  12. 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

  13. Location of Symbionts in the Whitefly Bemisia tabaci Affects Their Densities during Host Development and Environmental Stress

    Science.gov (United States)

    Su, Qi; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Ghanim, Murad; Zhang, Youjun

    2014-01-01

    Bacterial symbionts often enhance the physiological capabilities of their arthropod hosts and enable their hosts to expand into formerly unavailable niches, thus leading to biological diversification. Many arthropods, including the worldwide invasive whitefly Bemisia tabaci, have individuals simultaneously infected with symbionts of multiple genera that occur in different locations in the host. This study examined the population dynamics of symbionts that are located in different areas within B. tabaci. While densities of Portiera and Hamiltonella (which are located in bacteriocytes) appeared to be well-regulated during host development, densities of Rickettsia (which are not located in bacteriocytes) were highly variable among individual hosts during host development. Host mating did not significantly affect symbiont densities. Infection by Tomato yellow leaf curl virus did not affect Portiera and Hamiltonella densities in either sex, but increased Rickettsia densities in females. High and low temperatures did not affect Portiera and Hamiltonella densities, but low temperature (15°C) significantly suppressed Rickettsia densities whereas high temperature (35°C) had little effect on Rickettsia densities. The results are consistent with the view that the population dynamics of bacterial symbionts in B. tabaci are regulated by symbiont location within the host and that the regulation reflects adaptation between the bacteria and insect. PMID:24632746

  14. Competitive ability and fitness differences between two introduced populations of the invasive whitefly Bemisia tabaci Q in China.

    Directory of Open Access Journals (Sweden)

    Yi-Wei Fang

    Full Text Available BACKGROUND: Our long-term field survey revealed that the Cardinium infection rate in Bemisia tabaci Q (also known as biotype Q population was low in Shandong, China over the past few years. We hypothesize that (1 the Cardinium-infected (C+ B. tabaci Q population cannot efficiently compete with the Cardinium-uninfected (C- B. tabaci Q population; (2 no reproductive isolation may have occurred between C+ and C-; and (3 the C- population has higher fitness than the C+ population. METHODOLOGY AND RESULTS: To reveal the differences in competitive ability and fitness between the two introduced populations (C+ and C-, competition between C+ and C- was examined over several generations. Subsequently, the reproductive isolation between C+ and C- was studied by crossing C+ with C- individuals, and the fitnesses of C+ and C- populations were compared using a two-sex life table method. Our results demonstrate that the competitive ability of the C+ whiteflies was weaker than that of C-. There is that no reproductive isolation occurred between the two populations and the C- population had higher fitness than the C+ population. CONCLUSION: The competitive ability and fitness differences of two populations may explain why C- whitefly populations have been dominant during the past few years in Shandong, China. However, the potential role Cardinium plays in whitefly should be further explored.

  15. Only a minority of broad-range detoxification genes respond to a variety of phytotoxins in generalist Bemisia tabaci species.

    Science.gov (United States)

    Halon, Eyal; Eakteiman, Galit; Moshitzky, Pnina; Elbaz, Moshe; Alon, Michal; Pavlidi, Nena; Vontas, John; Morin, Shai

    2015-12-10

    Generalist insect can utilize two different modes for regulating their detoxification genes, the constitutive mode and the induced mode. Here, we used the Bemisia tabaci sibling species MEAM1 and MED, as a model system for studying constitutive and induced detoxification resistance and their associated tradeoffs. B. tabaci adults were allowed to feed through membranes for 24 h on diet containing only sucrose or sucrose with various phytotoxins. Quantitative real-time PCR analyses of 18 detoxification genes, indicated that relatively few transcripts were changed in both the MEAM1 and MED species, in response to the addition of phytotoxins to the diet. Induced transcription of detoxification genes only in the MED species, in response to the presence of indole-3-carbinol in the insect's diet, was correlated with maintenance of reproductive performance in comparison to significant reduction in performance of the MEAM1 species. Three genes, COE2, CYP6-like 5 and BtGST2, responded to more than one compound and were highly transcribed in the insect gut. Furthermore, functional assays showed that the BtGST2 gene encodes a protein capable of interacting with both flavonoids and glucosinolates. In conclusion, several detoxification genes were identified that could potentially be involved in the adaptation of B. tabaci to its host plants.

  16. Incidence and characterisation of resistance to neonicotinoid insecticides and pymetrozine in the greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Karatolos, Nikos; Denholm, Ian; Williamson, Martin; Nauen, Ralf; Gorman, Kevin

    2010-12-01

    Trialeurodes vaporariorum (Westwood), also known as the greenhouse whitefly, is a serious pest of protected vegetable and ornamental crops in most temperate regions of the world. Neonicotinoid insecticides are used widely to control this species, although resistance has been reported and may be becoming widespread. Mortality rates of UK and European strains of T. vaporariorum to a range of neonicotinoids and pymetrozine, a compound with a different mode of action, were calculated, and significant resistance was found in some of those strains. A strong association was found between neonicotinoids and pymetrozine, and reciprocal selection experiments confirmed this finding. Expression of resistance to the neonicotinoid imidacloprid and pymetrozine was age specific, and resistance in nymphs did not compromise recommended application rates. This study indicates strong parallels in the phenotypic characteristics of neonicotinoid resistance in T. vaporariorum and the tobacco whitefly Bemisia tabaci Gennadius, suggesting possible parallels in the underlying mechanisms. Copyright © 2010 Society of Chemical Industry.

  17. Replication of Tomato Yellow Leaf Curl Virus in Its Whitefly Vector, Bemisia tabaci.

    Science.gov (United States)

    Pakkianathan, Britto Cathrin; Kontsedalov, Svetlana; Lebedev, Galina; Mahadav, Assaf; Zeidan, Muhammad; Czosnek, Henryk; Ghanim, Murad

    2015-10-01

    Tomato yellow leaf curl virus (TYLCV) is a begomovirus transmitted exclusively by the whitefly Bemisia tabaci in a persistent, circulative manner. Replication of TYLCV in its vector remains controversial, and thus far, the virus has been considered to be nonpropagative. Following 8 h of acquisition on TYLCV-infected tomato plants or purified virions and then transfer to non-TYLCV-host cotton plants, the amounts of virus inside whitefly adults significantly increased (>2-fold) during the first few days and then continuously decreased, as measured by the amounts of genes on both virus DNA strands. Reported alterations in insect immune and defense responses upon virus retention led us to hypothesize a role for the immune response in suppressing virus replication. After virus acquisition, stress conditions were imposed on whiteflies, and the levels of three viral gene sequences were measured over time. When whiteflies were exposed to TYLCV and treatment with two different pesticides, the virus levels continuously increased. Upon exposure to heat stress, the virus levels gradually decreased, without any initial accumulation. Switching of whiteflies between pesticide, heat stress, and control treatments caused fluctuating increases and decreases in virus levels. Fluorescence in situ hybridization analysis confirmed these results and showed virus signals inside midgut epithelial cell nuclei. Combining the pesticide and heat treatments with virus acquisition had significant effects on fecundity. Altogether, our results demonstrate for the first time that a single-stranded DNA plant virus can replicate in its hemipteran vector. Plant viruses in agricultural crops are of great concern worldwide. Many of them are transmitted from infected to healthy plants by insects. Persistently transmitted viruses often have a complex association with their vectors; however, most are believed not to replicate within these vectors. Such replication is important, as it contributes to the

  18. Population Fluctuation and Altitudinal Distribution of Tetraleurodes perseae (Nakahara) (Hemiptera: Aleyrodidae) in Avocado (Lauraceae) in Morelos, Mexico

    Science.gov (United States)

    García-Palacios, Daniel; Bautista-Martínez, Néstor; Lagunes-Tejeda, Ángel; Carrillo-Sánchez, José Luis; Nieto-Ángel, Daniel; García-Gutiérrez, Cipriano

    2016-01-01

    Although whiteflies Tetraleurodes perseae (Nakahara) (Hemiptera: Aleyrodidae) are considered a secondary pest of avocado crops, their presence and the damages that they cause can decrease crop vigor and affect production. The objective of the present work was to determine the population fluctuation and altitudinal distribution of the T. perseae Nakahara whitefly in avocado trees, as well as to determine the number of possible generations in one year. The study was done in three orchards in Morelos state, located at different altitudes, from February 2014 to April 2015. Samplings were done every 21 days from 10 randomly chosen trees in each orchard. The samples were taken randomly from the middle stratus (1.6 m in height) of each tree; in buds or young leaves for the number of adults and leaves only for nymphs. Additionally, two yellow traps (7 × 14 cm) with glue were placed in each tree for adult samplings. Data were collected regarding vegetative budding, rainfall, relative humidity, and temperature. T. perseae was present in all three sampled orchards, with a greater presence in the lowest orchard, during the whole study period. In the orchard with the lowest altitudinal gradient (1,736 masl), 11 whitefly generations developed; 10 generations developed in the medium gradient orchard (1,934 masl); and 8 generations developed in the highest orchard (2,230 masl). The adults showed a positive relationship with regard to vegetative buds, while the nymphs had a negative relationship with regard to relative humidity. The rest of the parameters showed diverse effects on the species depending on the altitude of the orchard. PMID:27658809

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

    Science.gov (United States)

    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.

  20. Comparative transcriptome analysis reveals networks of genes activated in the whitefly, Bemisia tabaci when fed on tomato plants infected with Tomato yellow leaf curl virus.

    Science.gov (United States)

    Hasegawa, Daniel K; Chen, Wenbo; Zheng, Yi; Kaur, Navneet; Wintermantel, William M; Simmons, Alvin M; Fei, Zhangjun; Ling, Kai-Shu

    2018-01-01

    The whitefly Bemisia tabaci can transmit hundreds of viruses to numerous agricultural crops in the world. Five genera of viruses, including Begomovirus and Crinivirus, are transmitted by B. tabaci. There is little knowledge about the genes involved in virus acquisition and transmission by whiteflies. Using a comparative transcriptomics approach, we evaluated the gene expression profiles of whiteflies (B. tabaci MEAM1) after feeding on tomato infected by a begomovirus, Tomato yellow leaf curl virus (TYLCV), in comparison to a recent study, in which whiteflies were fed on tomato infected by the crinivirus, Tomato chlorosis virus (ToCV). The data revealed similar temporal trends in gene expression, but large differences in the number of whitefly genes when fed on TYLCV or ToCV-infected tomato. Transcription factors, cathepsins, receptors, and a hemocyanin gene, which is implicated in mediating antiviral immune responses in other insects and possibly virus transmission, were some of the genes identified. Published by Elsevier Inc.

  1. Survey of indigenous entomopathogenic fungi and evaluation of their pathogenicity against the carmine spider mite, Tetranychus cinnabarinus (Boisd.), and the whitefly, Bemisia tabaci (Genn.) biotype B.

    Science.gov (United States)

    Topuz, Emine; Erler, Fedai; Gumrukcu, Emine

    2016-12-01

    The carmine spider mite, Tetranychus cinnabarinus, and the silverleaf whitefly, Bemisia tabaci, are serious pests of both field- and greenhouse-grown crops in south-western Turkey. Control of these pests has been heavily dependent upon chemical pesticides. The objectives of this study were to investigate the occurrence of indigenous entomopathogenic fungi (EPF) in field populations of T. cinnabarinus and B. tabaci, and to evaluate their pathogenicity against these pests. For this purpose, a survey of EPF isolated from field-collected samples of both pests was carried out in Antalya in 2010 and 2011 using the dilution plating method. Four indigenous Beauveria bassiana isolates (TUR1-B, TUR2-B, FIN1-B, FIN2-B) were recovered. In pathogenicity bioassays with T. cinnabarinus and B. tabaci biotype B, all the isolates tested were pathogenic to some of the biological stages of both pests to varying degrees. FIN1-B and TUR1-B caused mortalities of up to 50 and 45%, respectively, in adults of T. cinnabarinus, and of over 79 and 37%, respectively, in pupae of B. tabaci with 10 7 conidia mL -1 suspensions under laboratory conditions 10 days after inoculation. FIN2-B and TUR2-B had mortalities of 19.45 and 12.28%, respectively, in adults of T. cinnabarinus, and of 6.78 and 8.18%, respectively, in pupae of B. tabaci. None of the isolates had an effect on eggs of either species and larvae of the mite. Overall results suggest that isolates FIN1-B and TUR1-B have potential for management of T. cinnabarinus and B. tabaci. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  2. Cloning, expression and characterization of mitochondrial manganese superoxide dismutase from the Whitefly, Bemisia tabaci.

    Science.gov (United States)

    Gao, Xian-Long; Li, Jun-Min; Wang, Yong-Liang; Jiu, Min; Yan, Gen-Hong; Liu, Shu-Sheng; Wang, Xiao-Wei

    2013-01-07

    A mitochondrial manganese superoxide dismutase from an invasive species of the whitefly Bemisia tabaci complex (Bt-mMnSOD) was cloned and analyzed. The full length cDNA of Bt-mMnSOD is 1210 bp with a 675 bp open reading frame, corresponding to 224 amino acids, which include 25 residues of the mitochondrial targeting sequence. Compared with various vertebrate and invertebrate animals, the MnSOD signature (DVWEHAYY) and four conserved amino acids for manganese binding (H54, H102, D186 and H190) were observed in Bt-mMnSOD. Recombinant Bt-mMnSOD was overexpressed in Escherichia coli, and the enzymatic activity of purified mMnSOD was assayed under various temperatures. Quantitative real-time PCR analysis with whiteflies of different development stages showed that the mRNA levels of Bt-mMnSOD were significantly higher in the 4th instar than in other stages. In addition, the in vivo activities of MnSOD in the whitefly were measured under various conditions, including exposure to low (4 °C) and high (40 °C) temperatures, transfer from a favorable to an unfavorable host plant (from cotton to tobacco) and treatment with pesticides. Our results indicate that the whitefly MnSOD plays an important role in cellular stress responses and anti-oxidative processes and that it might contribute to the successful worldwide distribution of the invasive whitefly.

  3. Cloning, Expression and Characterization of Mitochondrial Manganese Superoxide Dismutase from the Whitefly, Bemisia tabaci

    Science.gov (United States)

    Gao, Xian-Long; Li, Jun-Min; Wang, Yong-Liang; Jiu, Min; Yan, Gen-Hong; Liu, Shu-Sheng; Wang, Xiao-Wei

    2013-01-01

    A mitochondrial manganese superoxide dismutase from an invasive species of the whitefly Bemisia tabaci complex (Bt-mMnSOD) was cloned and analyzed. The full length cDNA of Bt-mMnSOD is 1210 bp with a 675 bp open reading frame, corresponding to 224 amino acids, which include 25 residues of the mitochondrial targeting sequence. Compared with various vertebrate and invertebrate animals, the MnSOD signature (DVWEHAYY) and four conserved amino acids for manganese binding (H54, H102, D186 and H190) were observed in Bt-mMnSOD. Recombinant Bt-mMnSOD was overexpressed in Escherichia coli, and the enzymatic activity of purified mMnSOD was assayed under various temperatures. Quantitative real-time PCR analysis with whiteflies of different development stages showed that the mRNA levels of Bt-mMnSOD were significantly higher in the 4th instar than in other stages. In addition, the in vivo activities of MnSOD in the whitefly were measured under various conditions, including exposure to low (4 °C) and high (40 °C) temperatures, transfer from a favorable to an unfavorable host plant (from cotton to tobacco) and treatment with pesticides. Our results indicate that the whitefly MnSOD plays an important role in cellular stress responses and anti-oxidative processes and that it might contribute to the successful worldwide distribution of the invasive whitefly. PMID:23296268

  4. Cloning, Expression and Characterization of Mitochondrial Manganese Superoxide Dismutase from the Whitefly, Bemisia tabaci

    Directory of Open Access Journals (Sweden)

    Xian-Long Gao

    2013-01-01

    Full Text Available A mitochondrial manganese superoxide dismutase from an invasive species of the whitefly Bemisia tabaci complex (Bt-mMnSOD was cloned and analyzed. The full length cDNA of Bt-mMnSOD is 1210 bp with a 675 bp open reading frame, corresponding to 224 amino acids, which include 25 residues of the mitochondrial targeting sequence. Compared with various vertebrate and invertebrate animals, the MnSOD signature (DVWEHAYY and four conserved amino acids for manganese binding (H54, H102, D186 and H190 were observed in Bt-mMnSOD. Recombinant Bt-mMnSOD was overexpressed in Escherichia coli, and the enzymatic activity of purified mMnSOD was assayed under various temperatures. Quantitative real-time PCR analysis with whiteflies of different development stages showed that the mRNA levels of Bt-mMnSOD were significantly higher in the 4th instar than in other stages. In addition, the in vivo activities of MnSOD in the whitefly were measured under various conditions, including exposure to low (4 °C and high (40 °C temperatures, transfer from a favorable to an unfavorable host plant (from cotton to tobacco and treatment with pesticides. Our results indicate that the whitefly MnSOD plays an important role in cellular stress responses and anti-oxidative processes and that it might contribute to the successful worldwide distribution of the invasive whitefly.

  5. Seasonal dynamics and management of whitefly ( Bemesia tabaci Genn. in tomato ( Solanum esculentum Mill.

    Directory of Open Access Journals (Sweden)

    Devinder Sharma

    2017-08-01

    Full Text Available ABSTRACT Studies on seasonal dynamics of white fly (Bemesia tabaci on tomato (Solanum esculentum var. Pusa Ruby revealed that it appeared first during the 13th and reached maximum during 21st standard meteorological week. A positive correlation between adult population and abiotic factors viz. temperature (maximum and minimum and sunshine hours was observed, whereas humidity (maximum and minimum and rainfall showed a negative correlation with it. Taken together, the key weather parameters studied, caused 89.00 per cent variation in whitefly population (R2 value. Combination of carbofuran (soil application + imidacloprid (seed treatment + imidacloprid (foliar application proved significantly superior and caused maximum reduction in whitefly population followed by imidacloprid (seed treatment + thiomethoxam (spray, imidacloprid (seed treatment + imidacloprid (spray, imidacloprid (seed treatment + dimetheoate (spray, carbofuran (soil application + malathion (spray, and imidacloprid (seed treatment + yellow sticky traps. The highest cost benefit ratio of 1:25.04 was recorded in case of carbofuran (soil application + imidacloprid (seed treatment + imidacloprid (foliar application followed by 1:22.38 for imidacloprid (seed treatment + thiomethoxam (spray ; 1:21.81 for imidacloprid (seed treatment + imidacloprid (spray; 1:19.27 imidacloprid (seed treatment + dimetheoate (spray; 1:19.48 carbofuran (soil application + malathion (spray, and 1:8.33 for imidacloprid (seed treatment + yellow sticky traps. The soil application of carbofuran + seed treatment with imidacloprid and three foliar sprays of imidacloprid at fortnight interval starting 40 days after transplanting is found effective and is advised for whitefly management in susceptible tomato cultivars.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  8. Effects of heat stress on survival of Frankliniella occidentalis (Thysanoptera: Thripidae) and Thrips tabaci (Thysanoptera: Thripidae).

    Science.gov (United States)

    Wang, J C; Zhang, B; Wang, J P; Li, H G; Wang, S F; Sun, L J; Zheng, C Y

    2014-08-01

    Temperature is known to play a crucial role in the population dynamics of insects. Insects have evolved different mechanisms to resist unfavorable extreme temperatures. In recent years, western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), and onion thrips, Thrips tabaci (Lindeman) (Thysanoptera: Thripidae), have caused significant damage to vegetable crops. Because of global warming and expanding areas of vegetable cultivation, a study of the effects of heat stress on these thrips species is warranted. We exposed the various developmental stages of western flower thrips and onion thrips to temperatures of 41, 43, or 45 degrees C for 2, 6, 12, 24, or 36 h to determine the effects of heat stress on survival. Our results showed that the heat resistance of nonadult western flower thrips was greater than that of the nonadult onion thrips, and that the natural heat resistant ability was the primary factor in heat resistance in western flower thrips. In contrast, the heat resistance of adult onion thrips was greater than that of the adult western flower thrips, which was primarily the result of the ability of searching suitable microenvironment that enabled the onion thrips to mitigate the effects of high temperatures more efficiently than the western flower thrips. Our analysis of the differences in heat resistance between western flower thrips and onion thrips provides important information for the development of thermal treatments for controlling western flower thrips and onion thrips.

  9. Development of Bemisia tabaci (Gennadius,1889 biotype B on Lycopersicon spp. genotypes

    Directory of Open Access Journals (Sweden)

    Marilene Fancelli

    2002-01-01

    Full Text Available Whiteflies are phytophagous insects, whose nymphs and adults suck the phloem sap, causing direct damage due to host plant weakness. In tomato (Lycopersicon spp. crops, they are important vectors of limiting fitoviruses. The objective of this study was to determine the effects of Lycopersicon spp. genotypes on Bemisia tabaci (Gennadius, 1889 biotype B development under greenhouse conditions. The evaluated genotypes were LA462 (L. peruvianum, LA716 (L. pennellii, LA1584 (L. pimpinellifolium, LA1609 (L. peruvianum, LA1739 (L. hirsutum, P25 (L. esculentum, PI134417 (L. hirsutum f. glabratum and Santa Clara (L. esculentum. LA716 was non-preferred for oviposition by the whitefly, which suggests an antixenotic effect. LA1584 showed an antibiotic resistance because nymphal survival was reduced and nymphal developmental time was increased. Antixenotic resistance was observed in LA1739 and PI134417, based on a reduction of oviposition. PI134417 also reduced nymphal survival, which suggests an antibiotic effect, but LA1739 was suitable for insect development. LA1609 was highly preferred for oviposition, however it reduced insect survival. P25 and Santa Clara (L. esculentum were highly preferred for oviposition.

  10. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  12. Vector-Enabled Metagenomic (VEM Surveys Using Whiteflies (Aleyrodidae Reveal Novel Begomovirus Species in the New and OldWorlds

    Directory of Open Access Journals (Sweden)

    Karyna Rosario

    2015-10-01

    Full Text Available Whitefly-transmitted viruses belonging to the genus Begomovirus (family Geminiviridae represent a substantial threat to agricultural food production. The rapid evolutionary potential of these single-stranded DNA viruses combined with the polyphagous feeding behavior of their whitefly vector (Bemisia tabaci can lead to the emergence of damaging viral strains. Therefore, it is crucial to characterize begomoviruses circulating in different regions and crops globally. This study utilized vector-enabled metagenomics (VEM coupled with high-throughput sequencing to survey begomoviruses directly from whiteflies collected in various locations (California (USA, Guatemala, Israel, Puerto Rico, and Spain. Begomoviruses were detected in all locations, with the highest diversity identified in Guatemala where up to seven different species were identified in a single field. Both bipartite and monopartite viruses were detected, including seven new begomovirus species from Guatemala, Puerto Rico, and Spain. This begomovirus survey extends the known diversity of these highly damaging plant viruses. However, the new genomes described here and in the recent literature appear to reflect the outcome of interactions between closely-related species, often resulting from recombination, instead of unique, highly divergent species.

  13. Vector-Enabled Metagenomic (VEM) Surveys Using Whiteflies (Aleyrodidae) Reveal Novel Begomovirus Species in the New and Old Worlds.

    Science.gov (United States)

    Rosario, Karyna; Seah, Yee Mey; Marr, Christian; Varsani, Arvind; Kraberger, Simona; Stainton, Daisy; Moriones, Enrique; Polston, Jane E; Duffy, Siobain; Breitbart, Mya

    2015-10-26

    Whitefly-transmitted viruses belonging to the genus Begomovirus (family Geminiviridae) represent a substantial threat to agricultural food production. The rapid evolutionary potential of these single-stranded DNA viruses combined with the polyphagous feeding behavior of their whitefly vector (Bemisia tabaci) can lead to the emergence of damaging viral strains. Therefore, it is crucial to characterize begomoviruses circulating in different regions and crops globally. This study utilized vector-enabled metagenomics (VEM) coupled with high-throughput sequencing to survey begomoviruses directly from whiteflies collected in various locations (California (USA), Guatemala, Israel, Puerto Rico, and Spain). Begomoviruses were detected in all locations, with the highest diversity identified in Guatemala where up to seven different species were identified in a single field. Both bipartite and monopartite viruses were detected, including seven new begomovirus species from Guatemala, Puerto Rico, and Spain. This begomovirus survey extends the known diversity of these highly damaging plant viruses. However, the new genomes described here and in the recent literature appear to reflect the outcome of interactions between closely-related species, often resulting from recombination, instead of unique, highly divergent species.

  14. 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...

  15. 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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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)).

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

    International Nuclear Information System (INIS)

    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)

  19. Distribution Pattern of Sweet Potato Whitefly Bemisia tabaci (Gennadius on Tomato Plants

    Directory of Open Access Journals (Sweden)

    K.M. Azam

    1997-01-01

    Full Text Available A field experiment was conducted to study the intra plant distribution and temporal dispersion patterns of whitetly (Bemisia tabaci Gennadius eggs and nymphs on tomato plants to establish a sampling method which would give accurate estimates of the population size. From the third week to the ninth week after transplanting, terminal leaflets were collected from the outer and inner canopies of each of the upper, middle, and lower plant strata. A strong ovipositional preference was found in whitefly adults at an early crop age. A maximum of 50.6% of the eggs were deposited in the middle stratum followed by upper (36. 15% and lower strata (13.3%. However, most of the nymphs (65.5% were present in the lower stratum followed by middle (32.4% and upper strata (2. l %. These findings indicated that when taking observations in egg counts the most preferred site is the upper and middle strata while for nymphal counts it is the lower and middle strata. There was a sharp decrease in egg and nymphal counts from the seventh week after transplantation which clearly indicated that, after this age , the corp is not preferred by whitefly . Egg and nymphal population of whitefly on tomato plants in the field were distributed in aggregates as evident by high variance to mean ratio. Values ranged from 2.72 to 14.36 and 4.52 to 21.82 for egg counts and nymphal population, respectively.  Aggregation of whitefly eggs and nymphs in all cases might be due to the behavior of adults to congregate and to the heterogeneity of the environment . The appropriate number of leaflets required for the estimation of egg density at 10% and 20% error was found to be 149 and 37, respectively. In the case of nymphal population the numbers were 163 and 41 at 10% and 20% error, respectively.

  20. A Primary Screening and Applying of Plant Volatiles as Repellents to Control Whitefly Bemisia tabaci (Gennadius) on Tomato

    Science.gov (United States)

    Du, Wenxiao; Han, Xiaoqing; Wang, Yubo; Qin, Yuchuan

    2016-02-01

    With the goal of finding a new way to reduce population densities of Bemisia tabaci biotype Q in greenhouses, seven repellent volatile chemicals and their combinations were screened. The mixture of DLCO (D-limonene, citral and olive oil (63:7:30)) had a better cost performance(SC50 = 22.59 mg/ml)to repel whiteflies from settling than the other mixtures or single chemicals. In the greenhouse, in both the choice test and the no-choice tests, the number of adult whiteflies that settled on 1% DLCO-treated tomato plants was significantly lower than those settling on the control plants for the different exposure periods (P  0.05) between the number of eggs on treated and control plants in the no-choice test. Compared with the controls, 1% DLCO did not cause significantly statistic mortality rates (P > 0.05) out of different living stages of B. tabaci. The tests for evaluating the repellent efficacy, showed that a slow-releasing bottle containing the mixture had a period of efficacy of 29 days, and the application of this mixture plus a yellow board used as a push-pull strategy in the greenhouse was also effective.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Margarita Hadjistylli

    Full Text Available 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

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Diseño de planes de muestreo con niveles fijos de precisión del pulgón manchado de la alfalfa, Therioaphis trifolii Monell (Homoptera: Aphididae) en alfalfa (Medicago sativa L.)

    OpenAIRE

    Gyenge, Javier E.; Trumper, Eduardo V.; Edelstein, Julio D.

    1999-01-01

    El objetivo de este trabajo fue construir planes secuenciales de muestreo para el pulgón manchado de la alfalfa, Therioaphis trifolii Monell (Homoptera: Aphididae), con niveles fijos de precisión para estimar su densidad en función de toma de decisiones. El estudio de la disposición espacial basado en la Ley de Potencia de Taylor y regresión de Iwao, indicó que esta especie se distribuye de manera agregada en el cultivo de alfalfa, aunque con diferentes grados de agregación según el estado de...

  7. Transmission of Squash vein yellowing virus to and From Cucurbit Weeds and Effects on Sweetpotato Whitefly (Hemiptera: Aleyrodidae) Behavior.

    Science.gov (United States)

    Shrestha, D; McAuslane, H J; Adkins, S T; Smith, H A; Dufault, N; Webb, S E

    2016-08-01

    Since 2003, growers of Florida watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] have periodically suffered large losses from a disease caused by Squash vein yellowing virus (SqVYV), which is transmitted by the whitefly Middle East-Asia Minor 1 (MEAM1), formerly Bemisia tabaci (Gennadius) biotype B. Common cucurbit weeds like balsam apple (Momordica charantia L.) and smellmelon [Cucumis melo var. dudaim (L.) Naud.] are natural hosts of SqVYV, and creeping cucumber (Melothria pendula L.) is an experimental host. Study objectives were to compare these weeds and 'Mickylee' watermelon as sources of inoculum for SqVYV via MEAM1 transmission, to determine weed susceptibility to SqVYV, and to evaluate whitefly settling and oviposition behaviors on infected vs. mock-inoculated (inoculated with buffer only) creeping cucumber leaves. We found that the lowest percentage of watermelon recipient plants was infected when balsam apple was used as a source of inoculum. Watermelon was more susceptible to infection than balsam apple or smellmelon. However, all weed species were equally susceptible to SqVYV when inoculated by whitefly. For the first 5 h after release, whiteflies had no preference to settle on infected vs. mock-inoculated creeping cucumber leaves. After 24 h, whiteflies preferred to settle on mock-inoculated leaves, and more eggs were laid on mock-inoculated creeping cucumber leaves than on SqVYV-infected leaves. The transmission experiments (source of inoculum and susceptibility) show these weed species as potential inoculum sources of the virus. The changing settling preference of whiteflies from infected to mock-inoculated plants could lead to rapid spread of virus in the agroecosystem. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the United States.

  8. Host-Mediated Effects of Semipersistently Transmitted Squash Vein Yellowing Virus on Sweetpotato Whitefly (Hemiptera: Aleyrodidae) Behavior and Fitness.

    Science.gov (United States)

    Shrestha, Deepak; McAuslane, Heather J; Adkins, Scott T; Smith, Hugh A; Dufault, Nicholas; Colee, James; Webb, Susan E

    2017-08-01

    Plant viruses may indirectly affect insect vector behavior and fitness via a shared host plant. Here, we evaluated the host-mediated effects of Squash vein yellowing virus (SqVYV) on the behavior and fitness of its whitefly vector, Bemisia tabaci (Gennadius) Middle East-Asia Minor 1, formerly biotype B. Alighting, settling, and oviposition behavioral assays were conducted on infected and mock-inoculated squash (Cucurbita pepo L.) and watermelon [Citrullus lanatus (Thunb) Matsum and Nakai] plants. Developmental time of immature stages, adult longevity, and fecundity were measured on infected and mock-inoculated squash plants. For adult longevity and fecundity, whiteflies were reared on infected and mock-inoculated squash plants to determine the effects of nymphal rearing host on the adult stage. More whiteflies alighted and remained settled on infected squash than on mock-inoculated squash 0.25, 1, 8, and 24 h after release. No such initial preference was observed on watermelon plants, but by 8 h after release, more whiteflies were found on mock-inoculated watermelon plants than on infected plants. Whiteflies laid approximately six times more eggs on mock-inoculated watermelon than on infected watermelon; however, no differences were observed on squash. Development from egg to adult emergence was 3 d shorter on infected than mock-inoculated squash plants. Females lived 25% longer and had higher fecundity on infected squash plants than on mock-inoculated plants, regardless of infection status of the rearing host. The host-mediated effects of SqVYV infection on whitefly behavior differ on two cucurbit host plants, suggesting the potential for more rapid spread of the virus within watermelon fields. © 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.

  9. 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

  10. Download this PDF file

    African Journals Online (AJOL)

    E-mail: egetudegaga@yahoo.corn. ABSTRACT: The woolly whitefly, Aleurothrixus floccosus (Maskell) (Homoptera: Aleyrodidae), is a new invasive alien insect pest of .... thuringiensis (Bt) is recommended. However, when the pest just invaded a new country like Ethiopia now classical biological control is the approach to.

  11. Author Details

    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 Northwest and Central Nigeria Abstract · Vol 13, No 1 (2008) - Articles A Survey of Rootstock Usage and their Influence on Major Insects and Diseases ...

  12. Download this PDF file

    African Journals Online (AJOL)

    AJL

    Use of Beauveria bassiana (Bals) to control the immature stages of the whitefly, Trialeurodes vaporariorum. (Westwood) (Homoptera: Aleyrodidae) in the greenhouse. Arab. J. Plant Prot. 2:83-86. Van leeuwen T, Nauen R, Witters J, Duso C, Tirry L (2010).The control of eriophyoid mites: state of the art and future challenges.

  13. 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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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

  17. 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.

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

    Science.gov (United States)

    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.

  19. 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

  20. 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...

  1. Transcriptome analysis reveals a comprehensive insect resistance response mechanism in cotton to infestation by the phloem feeding insect Bemisia tabaci (whitefly)

    OpenAIRE

    Li, Jianying; Zhu, Lizhen; Hull, J. Joe; Liang, Sijia; Daniell, Henry; Jin, Shuangxia; Zhang, Xianlong

    2016-01-01

    Summary The whitefly (Bemisia tabaci) causes tremendous damage to cotton production worldwide. However, very limited information is available about how plants perceive and defend themselves from this destructive pest. In this study, the transcriptomic differences between two cotton cultivars that exhibit either strong resistance (HR) or sensitivity (ZS) to whitefly were compared at different time points (0, 12, 24 and 48?h after infection) using RNA?Seq. Approximately one billion paired?end r...

  2. Attraction of Three Mirid Predators to Tomato Infested by Both the Tomato Leaf Mining Moth Tuta absoluta and the Whitefly Bemisia tabaci.

    Science.gov (United States)

    Silva, Diego B; Bueno, Vanda H P; Van Loon, Joop J A; Peñaflor, Maria Fernanda G V; Bento, José Maurício S; Van Lenteren, Joop C

    2018-01-01

    Plants emit volatile compounds in response to insect herbivory, which may play multiple roles as defensive compounds and mediators of interactions with other plants, microorganisms and animals. Herbivore-induced plant volatiles (HIPVs) may act as indirect plant defenses by attracting natural enemies of the attacking herbivore. We report here the first evidence of the attraction of three Neotropical mirid predators (Macrolophus basicornis, Engytatus varians and Campyloneuropsis infumatus) toward plants emitting volatiles induced upon feeding by two tomato pests, the leaf miner Tuta absoluta and the phloem feeder Bemisia tabaci, in olfactometer bioassays. Subsequently, we compared the composition of volatile blends emitted by insect-infested tomato plants by collecting headspace samples and analyzing them with GC-FID and GC-MS. Egg deposition by T. absoluta did not make tomato plants more attractive to the mirid predators than uninfested tomato plants. Macrolophus basicornis is attracted to tomato plants infested with either T. absoluta larvae or by a mixture of B. tabaci eggs, nymphs and adults. Engytatus varians and C. infumatus responded to volatile blends released by tomato plants infested with T. absoluta larvae over uninfested plants. Also, multiple herbivory by T. absoluta and B. tabaci did not increase the attraction of the mirids compared to infestation with T. absoluta alone. Terpenoids represented the most important class of compounds in the volatile blends and there were significant differences between the volatile blends emitted by tomato plants in response to attack by T. absoluta, B. tabaci, or by both insects. We, therefore, conclude that all three mirids use tomato plant volatiles to find T. absoluta larvae. Multiple herbivory did neither increase, nor decrease attraction of C. infumatus, E. varians and M. basicornis. By breeding for higher rates of emission of selected terpenes, increased attractiveness of tomato plants to natural enemies may

  3. Binding of insecticidal lectin Colocasia esculenta tuber agglutinin (CEA) to midgut receptors of Bemisia tabaci and Lipaphis erysimi provides clues to its insecticidal potential.

    Science.gov (United States)

    Roy, Amit; Gupta, Sumanti; Hess, Daniel; Das, Kali Pada; Das, Sampa

    2014-07-01

    The insecticidal potential of Galanthus nivalis agglutinin-related lectins against hemipterans has been experimentally proven. However, the basis behind the toxicity of these lectins against hemipterans remains elusive. The present study elucidates the molecular basis behind insecticidal efficacy of Colocasia esculenta tuber agglutinin (CEA) against Bemisia tabaci and Lipaphis erysimi. Confocal microscopic analyses highlighted the binding of 25 kDa stable homodimeric lectin to insect midgut. Ligand blots followed by LC MS/MS analyses identified binding partners of CEA as vacuolar ATP synthase and sarcoplasmic endoplasmic reticulum type Ca(2+) ATPase from B. tabaci, and ATP synthase, heat shock protein 70 and clathrin heavy chain assembly protein from L. erysimi. Internalization of CEA into hemolymph was confirmed by Western blotting. Glycoprotein nature of the receptors was identified through glycospecific staining. Deglycosylation assay indicated the interaction of CEA with its receptors to be probably glycan mediated. Surface plasmon resonance analysis revealed the interaction kinetics between ATP synthase of B. tabaci with CEA. Pathway prediction study based on Drosophila homologs suggested the interaction of CEA with insect receptors that probably led to disruption of cellular processes causing growth retardation and loss of fecundity of target insects. Thus, the present findings strengthen our current understanding of the entomotoxic potentiality of CEA, which will facilitate its future biotechnological applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. 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.

  5. 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.

  6. Infection of Bacterial Endosymbionts in Insects: A Comparative Study of Two Techniques viz PCR and FISH for Detection and Localization of Symbionts in Whitefly, Bemisia tabaci.

    Directory of Open Access Journals (Sweden)

    Harpreet Singh Raina

    Full Text Available Bacterial endosymbionts have been associated with arthropods and large number of the insect species show interaction with such bacteria. Different approaches have been used to understand such symbiont- host interactions. The whitefly, Bemisia tabaci, a highly invasive agricultural pest, harbors as many as seven different bacterial endosymbionts. These bacterial endosymbionts are known to provide various nutritional, physiological, environmental and evolutionary benefits to its insect host. In this study, we have tried to compare two techniques, Polymerase chain reaction (PCR and Flourescence in situ Hybridisation (FISH commonly used for identification and localization of bacterial endosymbionts in B. tabaci as it harbors one of the highest numbers of endosymbionts which have helped it in becoming a successful global invasive agricultural pest. The amplified PCR products were observed as bands on agarose gel by electrophoresis while the FISH samples were mounted on slides and observed under confocal microscope. Analysis of results obtained by these two techniques revealed the advantages of FISH over PCR. On a short note, performing FISH, using LNA probes proved to be more sensitive and informative for identification as well as localization of bacterial endosymbionts in B. tabaci than relying on PCR. This study would help in designing more efficient experiments based on much reliable detection procedure and studying the role of endosymbionts in insects.

  7. 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

    Directory of Open Access Journals (Sweden)

    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.

  8. 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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

  10. Preference of Bemisia tabaci biotype B on zucchini squash and buckwheat and the effect of Delphastus catalinae on whitefly populations.

    Science.gov (United States)

    Razze, Janine M; Liburd, Oscar E; McSorley, Robert

    2016-07-01

    Zucchini squash, Cucurbita pepo L., is an important vegetable crop in Florida. Physiological disorders and insect-transmitted diseases are major problems for squash growers in semi-tropical regions around the world. Bemisia tabaci (Gennadius) biotype B is a significant whitefly pest and is largely responsible for transmitting viruses and causing physiological disorders in squash. Several studies have shown that whitefly populations are reduced when crops are interplanted with non-host cover crops or mulches. The aim of the present study was to determine how the presence of buckwheat, Fagopyrum esculentum Moench, and a key predator, Delphastus catalinae (Horn), affect whitefly colonization on squash. Whitefly densities were higher on squash than on buckwheat. The introduction of D. catalinae on squash significantly reduced whitefly populations. Overall, there were higher densities of D. catalinae on squash where the whitefly pest was more concentrated compared with buckwheat. The study provided preliminary evidence that D. catalinae, when used in conjunction with buckwheat as a living mulch, may aid in reducing whiteflies in squash. This greenhouse experiment highlights the need to investigate a multitactic approach of intercropping buckwheat with squash and the incorporation of D. catalinae in the field to manage populations of whiteflies and whitefly-transmitted diseases. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  11. Use of the synergist piperonyl butoxide can slow the development of alpha-cypermethrin resistance in the whitefly Bemisia tabaci.

    Science.gov (United States)

    Zimmer, C T; Panini, M; Singh, K S; Randall, E L; Field, L M; Roditakis, E; Mazzoni, E; Bass, C

    2017-04-01

    The development of insecticide resistance in insect pests of crops is a growing threat to sustainable food production, and strategies that slow the development of resistance are therefore urgently required. The insecticide synergist piperonyl butoxide (PBO) inhibits certain insect detoxification systems and so may delay the evolution of metabolic resistance. In the current study we characterized resistance development in the silverleaf whitefly, Bemisia tabaci, after selection with either a neonicotinoid (thiacloprid) or pyrethroid (alpha-cypermethrin) insecticide alone or in combination with PBO. Resistance development was significantly suppressed (> 60%) in the line selected with alpha-cypermethrin + PBO compared to the line selected with alpha-cypermethrin alone. RNA sequencing (RNAseq) analyses revealed an increase in frequency of a knock-down resistance mutation but no differentially expressed genes were identified that could explain the sensitivity shift. No significant difference was observed in the level of resistance between the thiacloprid and thiacloprid + PBO selected lines, and RNA sequencing (RNAseq) analyses revealed that the cytochrome P450 monooxygenase CYP6CM1, known to metabolize neonicotinoids, was significantly upregulated (>10-fold) in both lines. The findings of this study demonstrate that PBO used in combination with certain insecticides can suppress the development of resistance in a laboratory setting; however, the mechanism by which PBO supresses resistance development remains unclear. © 2016 The Royal Entomological Society.

  12. Comparison of transmission of Papaya leaf curl China virus among four cryptic species of the whitefly Bemisia tabaci complex

    Science.gov (United States)

    Guo, Tao; Guo, Qi; Cui, Xi-Yun; Liu, Yin-Quan; Hu, Jian; Liu, Shu-Sheng

    2015-01-01

    Begomoviruses are transmitted by cryptic species of the whitefly Bemisia tabaci complex, often in a species-specific manner. Papaya leaf curl China virus (PaLCuCNV) has been recorded to infect several crops including papaya, tomato and tobacco in China. To help assess the risks of spread of this virus, we compared the acquisition, retention and transmission of PaLCuCNV among four species of whiteflies, Middle East-Asia Minor 1 (MEAM1), Mediterranean (MED), Asia 1 and Asia II 7. All four species of whiteflies are able to acquire, retain and transmit the virus, but with different levels of efficiency. Transmission tests using tomato as the host plant showed that MEAM1 transmitted PaLCuCNV with substantially higher efficiency than did MED, Asia 1 and Asia II 7. Furthermore, accumulation of PaLCuCNV in the whiteflies was positively associated with its efficiency of transmitting the virus. Altogether, these findings indicate that MEAM1 is the most efficient vector for PaLCuCNV in the four species of whiteflies, and suggest that risks of PaLCuCNV pandemics are high in regions where MEAM1 occurs. PMID:26486606

  13. Aerial electrostatic-charged sprays for deposition and efficacy against sweet potato whitefly (Bemisia tabaci) on cotton.

    Science.gov (United States)

    Latheef, Mohamed A; Carlton, James B; Kirk, Ivan W; Hoffmann, W Clint

    2009-07-01

    The efficacy of aerial electrostatic-charged sprays was evaluated for spray deposit characteristics and season-long control of sweet potato whitefly (SWF), Bemisia tabaci Genn. biotype B (aka B. argentifolii Bellows & Perring), in an irrigated 24 ha cotton field. Treatments included electrostatic-charged sprays at full and half active ingredient (AI) label rate, uncharged sprays and conventional sprays applied with CP nozzles at full label rate with several different insecticides. Spray droplet size was significantly smaller for electrostatic-charged sprays than for conventional sprays in top- and mid-canopy locations. The seasonal mean numbers of viable eggs and live large nymphs on cotton treated with electrostatic-charged sprays were comparable with those on cotton treated with conventional applications. Lethal concentration (LC(50)) for adults for electrostatic-charged sprays was comparable with that for conventional sprays. The amenability of electrostatic-charged sprays to a wide array of pesticides with different chemistries should be a useful tool in combating insect resistance. Results reported here suggest that the potential exists for obtaining increased efficacy against whiteflies using an electrostatic spray charging system, and that additional research will be required to improve charge-to-mass (Q/M) ratio in order to increase deposition of pest control materials to the lower surfaces of cotton leaves where the whiteflies reside. (c) 2009 Society of Chemical Industry.

  14. Insects' RNA Profiling Reveals Absence of "Hidden Break" in 28S Ribosomal RNA Molecule of Onion Thrips, Thrips tabaci.

    Science.gov (United States)

    Macharia, Rosaline Wanjiru; Ombura, Fidelis Levi; Aroko, Erick Onyango

    2015-01-01

    With an exception of aphids, insects' 28S rRNA is thought to harbor a "hidden break" which cleaves under denaturing conditions to comigrate with 18S rRNA band to exhibit a degraded appearance on native agarose gels. The degraded appearance confounds determination of RNA integrity in laboratories that rely on gel electrophoresis. To provide guidelines for RNA profiles, RNA from five major insect orders, namely, Diptera, Hemiptera, Thysanoptera, Hymenoptera, and Lepidoptera, was compared under denaturing and nondenaturing conditions. This study confirmed that although present in most of insect's RNA, the "hidden break" is absent in the 28S rRNA of onion thrips, Thrips tabaci. On the other hand, presence of "hidden break" was depicted in whiteflies' 28S rRNA despite their evolutionary grouping under same order with aphids. Divergence of 28S rRNA sequences confirms variation of both size and composition of gap region among insect species. However, phylogeny reconstruction does not support speciation as a possible source of the hidden break in insect's 28S rRNA. In conclusion, we show that RNA from a given insect order does not conform to a particular banding profile and therefore this approach cannot be reliably used to characterize newly discovered species.

  15. Induction of Callose Deposition in Tobacco (Nicotiana tabacum by Bacterial Lipopolysaccharide Pseudomonas syringae pv. tabaci and Pseudomonas syringae pv. glycinea

    Directory of Open Access Journals (Sweden)

    Pipit Marianingsih

    2014-12-01

    Full Text Available Lipopolysaccharide (LPS is a major component of outer-membrane gram-negative bacteria, and it can act as a Pathogen-Associated Molecular Pattern (PAMP for perception of pathogens by plants. LPS can be recognized by plants, triggering certain plant defense-related responses, including callose deposition. This study investigated induction of callose deposition by bacterial LPS in tobacco. Tobacco leaves were infiltrated with 400 μg/mL and 800 μg/mL LPS extracted from Pseudomonas syringae pv. tabaci (Pta and Pseudomonas syringae pv. glycinea (Pgl and incubated for 24 h or 48 h. To detect callose deposition, tobacco leaves were cleared in lactophenol solution, stained with aniline blue, and visualized by fluorescence microscopy. Results showed that LPS from Pgl induced more callose deposition in tobacco leaves than did that from Pta. In addition, a Pearson correlation test revealed that incubation period was the most significant factor in callose deposition, followed by the type of LPS bacteria. However, LPS concentration was not significantly corelated to callose deposition in tobacco leaves.

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

    Science.gov (United States)

    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.

  17. 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)

  18. Transcription analysis of neonicotinoid resistance in Mediterranean (MED) populations of B. tabaci reveal novel cytochrome P450s, but no nAChR mutations associated with the phenotype.

    Science.gov (United States)

    Ilias, Aris; Lagnel, Jacques; Kapantaidaki, Despoina E; Roditakis, Emmanouil; Tsigenopoulos, Costas S; Vontas, John; Tsagkarakou, Anastasia

    2015-11-14

    Bemisia tabaci is one of the most damaging agricultural pests world-wide. Although its control is based on insecticides, B. tabaci has developed resistance against almost all classes of insecticides, including neonicotinoids. We employed an RNA-seq approach to generate genome wide expression data and identify genes associated with neonicotinoid resistance in Mediterranean (MED) B. tabaci (Q1 biotype). Twelve libraries from insecticide resistant and susceptible whitefly populations were sequenced on an Illumina Next-generation sequencing platform, and genomic sequence information of approximately 73 Gbp was generated. A reference transcriptome was built by de novo assembly and functionally annotated. A total of 146 P450s, 18 GSTs and 23 CCEs enzymes (unigenes) potentially involved in the detoxification of xenobiotics were identified, along with 78 contigs encoding putative target proteins of six different insecticide classes. Ten unigenes encoding nicotinic Acetylcholine Receptors (nAChR), the target of neoinicotinoids, were identified and phylogenetically classified. No nAChR polymorphism potentially related with the resistant phenotypes, was observed among the studied strains. DE analysis revealed that among the 550 differentially (logFC > 1) over-transcribed unigenes, 52 detoxification enzymes were over expressed including unigenes with orthologues in P450s, GSTs, CCE and UDP-glucuronosyltransferases. Eight P450 unigenes belonging to clades CYP2, CYP3 and CYP4 were highly up-regulated (logFC > 2) including CYP6CM1, a gene already known to confer imidacloprid resistance in B. tabaci. Using quantitative qPCRs, a larger screening of field MED B. tabaci from Crete with known neonicotinoid phenotype was performed to associate expression levels of P450s with resistance levels. Expression levels of five P450s, including CYP6CM1, were found associated with neonicotinoid resistance. However, a significant correlation was found only in CYP303 and CYP6CX3, with imidacloprid

  19. Dificultades metodológicas en la selección de cultivos trampa para el manejo del complejo Bemisia tabaci-virus en tomate

    OpenAIRE

    Luko Hilje; Philip A. Stansly

    2017-01-01

    Se describe la evolución de una metodología para la evaluación de cultivos trampa para el manejo de Bemisia tabaci (biotipo A) como vector de virus en tomate, en Costa Rica. Se evaluaron la vainica (Phaseolus vulgaris, Fabaceae), tabaco (Nicotiana tabacum, Solanaceae) y berenjena (Solanum melongena, Solanaceae). Aunque los tres cultivos redujeron el impacto del Tomato yellow mottled virus (ToYMoV) sobre los rendimientos, el tabaco y la berenjena fueron superiores. No obstante, la extrapolació...

  20. MicroRNA profiling of the whitefly Bemisia tabaci Middle East-Aisa Minor I following the acquisition of Tomato yellow leaf curl China virus.

    Science.gov (United States)

    Wang, Bi; Wang, Lanlan; Chen, Fangyuan; Yang, Xiuling; Ding, Ming; Zhang, Zhongkai; Liu, Shu-Sheng; Wang, Xiao-Wei; Zhou, Xueping

    2016-02-02

    The begomoviruses are the largest and most economically important group of plant viruses exclusively vectored by whitefly (Bemisia tabaci) in a circulative, persistent manner. During this process, begomoviruses and whitefly vectors have developed close relationships and complex interactions. However, the molecular mechanisms underlying these interactions remain largely unknown, and the microRNA profiles for viruliferous and nonviruliferous whiteflies have not been studied. Sequences of Argonaute 1(Ago1) and Dicer 1 (Dcr1) genes were cloned from B. tabaci MEAM1 cDNAs. Subsequently, deep sequencing of small RNA libraries from uninfected and Tomato yellow leaf curl China virus (TYLCCNV)-infected whiteflies was performed. The conserved and novel miRNAs were identified using the release of miRBase Version 19.0 and the prediction software miRDeep2, respectively. The sequencing results of selected deregulated and novel miRNAs were further confirmed using quantitative reverse transcription-PCR. Moreover, the previously published B. tabaci MEAM1 transcriptome database and the miRNA target prediction algorithm miRanda 3.1 were utilized to predict potential targets for miRNAs. Gene Ontology (GO) analysis was also used to classify the potential enriched functional groups of their putative targets. Ago1 and Dcr1orthologs with conserved domains were identified from B. tabaci MEAM1. BLASTn searches and sequence analysis identified 112 and 136 conserved miRNAs from nonviruliferous and viruliferous whitefly libraries respectively, and a comparison of the conserved miRNAs of viruliferous and nonviruliferous whiteflies revealed 15 up- and 9 down-regulated conserved miRNAs. 7 novel miRNA candidates with secondary pre-miRNA hairpin structures were also identified. Potential targets of conserved and novel miRNAs were predicted using GO analysis, for the targets of up- and down-regulated miRNAs, eight and nine GO terms were significantly enriched. We identified Ago1 and Dcr1 orthologs

  1. 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

    Directory of Open Access Journals (Sweden)

    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

  2. UTILIZATION OF THE BEFENTHRIN IN CHEMICAL CONTROL OF WHITE FLY (Bemisia tabaci, Genn. 1889 IN BEAN CROPS AVALIAÇÃO DO BEFENTHRIN NO CONTROLE DA MOSCA BRANCA (Bemisia tabaci, Genn. 1889 EM FEIJOEIRO

    Directory of Open Access Journals (Sweden)

    Demétrio Martinez Palhares

    2007-09-01

    Full Text Available

    The white fly (Bemisia tabaci, an important pest of bean crops, is known as vector of golden-yellow-mosaic virus in many regions in Brazil. In order to determine the efficiency of the befenthrin to control the white fly, a field experiment was carried out in Goiânia, State of Goiás, Brazil. The treatments and dosage in grams of active ingredient by ha were: befenthrin (2.5; 3.75; 5.0 and 6.25, metamidophós (420.0 and 600.0 and untreated check. Results obtained by this test permitted to conclude that befenthrin at experimented doses, presented similarity of control to the other used compound in different estimations realized, with control average superior to 96.0%.

    Com o objetivo de avaliar a eficiência do Befenthrin 25 CE, nas dosagens de 2,5 ; 3,75; 5,00 e 6,25g i.a/ha, no controle químico da mosca branca (Bemisia tabaci Genn., 1889 em feijoeiro, foi conduzido um experimento no Campo Experimental da Escola de Agronomia da Universidade Federal de Goiás - Goiânia, safra 91/92, utilizando como produto padrão o Metamidophós 600 BR nas dosagens de 420 e 600g i.a/ha. As pulverizações foram realizadas nos 7°, 14°, 21° e 28° dias após a emergência das plântulas, utilizando-se um pulverizador costal a CO2 com bico D3 gastando-se 250 litros de calda por ha. Dois dias após a última pulverização foi realizada a avaliação de eficiência, contando-se o número de ninfas vivas em 10 folíolos/parcela e, 10 dias após, fez-se a contagem do número de plantas com sintomas de “mosaico dourado” por parcela. Pelos resultados obtidos, conclui-se que o Befenthrin nas dosagens de 5,0 e 6,25g i.a./ha controlou eficientemente a praga, igualando-se ao metamidophós na dosagem de 600g i.a/ha, com a vantagem de menor toxicidade para mamíferos e também sob o ponto de vista ecol

  3. 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

    Directory of Open Access Journals (Sweden)

    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

  4. Temporal changes of symbiont density and host fitness after rifampicin treatment in a whitefly of the Bemisia tabaci species complex.

    Science.gov (United States)

    Shan, Hong-Wei; Zhang, Chang-Rong; Yan, Ting-Ting; Tang, Hai-Qin; Wang, Xiao-Wei; Liu, Shu-Sheng; Liu, Yin-Quan

    2016-04-01

    Microbial symbionts are essential or important partners to phloem-feeding insects. Antibiotics have been used to selectively eliminate symbionts from their host insects and establish host lines with or without certain symbionts for investigating functions of the symbionts. In this study, using the antibiotic rifampicin we attempted to selectively eliminate certain symbionts from a population of the Middle East-Asia Minor 1 whitefly of the Bemisia tabaci species complex, which harbors the primary symbiont "Candidatus Portiera aleyrodidarum" and two secondary symbionts "Candidatus Hamiltonella defensa" and Rickettsia. Neither the primary nor the secondary symbionts were completely depleted in the adults (F0) that fed for 48 h on a diet treated with rifampicin at concentrations of 1-100 μg/mL. However, both the primary and secondary symbionts were nearly completely depleted in the offspring (F1) of the rifampicin-treated adults. Although the F1 adults produced some eggs (F2), most of the eggs failed to hatch and none of them reached the second instar, and consequently the rifampicin-treated whitefly colony vanished at the F2 generation. Interestingly, quantitative polymerase chain reaction assays showed that in the rifampicin-treated whiteflies, the density of the primary symbiont was reduced at an obviously slower pace than the secondary symbionts. Mating experiments between rifampicin-treated and untreated adults demonstrated that the negative effects of rifampicin on host fitness were expressed when the females were treated by the antibiotic, and whether males were treated or not by the antibiotic had little contribution to the negative effects. These observations indicate that with this whitefly population it is not feasible to selectively eliminate the secondary symbionts using rifampicin without affecting the primary symbiont and establish host lines for experimental studies. However, the extinction of the whitefly colony at the second generation after

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

    Science.gov (United States)

    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

  6. Whitefly population dynamics in okra plantations

    OpenAIRE

    Leite,Germano Leão Demolin; Picanço,Marcelo; Jham,Gulab Newandram; Moreira,Márcio Dionízio

    2005-01-01

    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...

  7. 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

    Directory of Open Access Journals (Sweden)

    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

  8. 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

    Directory of Open Access Journals (Sweden)

    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

  9. Specific cells in the primary salivary glands of the whitefly Bemisia tabaci control retention and transmission of begomoviruses.

    Science.gov (United States)

    Wei, Jing; Zhao, Juan-Juan; Zhang, Tong; Li, Fang-Fang; Ghanim, Murad; Zhou, Xue-Ping; Ye, Gong-Yin; Liu, Shu-Sheng; Wang, Xiao-Wei

    2014-11-01

    The majority of plant viruses are vectored by arthropods via persistent-circulative or noncirculative transmission. Previous studies have shown that specific binding sites for noncirculative viruses reside within the stylet or foregut of insect vectors, whereas the transmission mechanisms of circulative viruses remain ambiguous. Here we report the critical roles of whitefly primary salivary glands (PSGs) in the circulative transmission of two begomoviruses. The Middle East Asia Minor 1 (MEAM1) species of the whitefly Bemisia tabaci complex efficiently transmits both Tomato yellow leaf curl China virus (TYLCCNV) and Tomato yellow leaf curl virus (TYLCV), whereas the Mediterranean (MED) species transmits TYLCV but not TYLCCNV. PCR and fluorescence in situ hybridization experiments showed that TYLCCNV efficiently penetrates the PSGs of MEAM1 but not MED whiteflies. When a fragment of the coat protein of TYLCCNV was exchanged with that of TYLCV, mutated TYLCCNV accumulated in the PSGs of MED whiteflies, while mutant TYLCV was nearly undetectable. Confocal microscopy revealed that virion transport in PSGs follows specific paths to reach secretory cells in the central region, and the accumulation of virions in the secretory region of PSGs was correlated with successful virus transmission. Our findings demonstrate that whitefly PSGs, in particular the cells around the secretory region, control the specificity of begomovirus transmission. Over 75% of plant viruses are transmitted by insects. However, the mechanisms of virus transmission by insect vectors remain largely unknown. Begomoviruses and whiteflies are a complex of viruses and vectors which threaten many crops worldwide. We investigated the transmission of two begomoviruses by two whitefly species. We show that specific cells of the whitefly primary salivary glands control viral transmission specificity and that virion transport in the glands follows specific paths to reach secretory cells in the central region and

  10. High ozone (O3 affects the fitness associated with the microbial composition and abundance of Q biotype Bemisia tabaci

    Directory of Open Access Journals (Sweden)

    Yanyun Hong

    2016-10-01

    hO3. Key words: Bemisia tabaci, high ozone (hO3, fitness, microbial communities, inside of the body, on the surface

  11. 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

    Directory of Open Access Journals (Sweden)

    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

  12. Genetic identity of the Bemisia tabaci species complex and association with high cotton leaf curl disease (CLCuD) incidence in Pakistan.

    Science.gov (United States)

    Ahmed, Muhammad Z; De Barro, Paul J; Greeff, Jaco M; Ren, Shun-Xiang; Naveed, Muhammad; Qiu, Bao-Li

    2011-03-01

    The cotton whitefly, Bemisia tabaci (Gennadius), is a cryptic species complex, and members of the complex have become serious pests in Pakistan because of their feeding and their ability to transmit cotton leaf curl virus (CLCuV). Here, an analysis was made of the identity of B. tabaci collected from cotton and a range of non-cotton hosts in the cotton-growing zones in Punjab and Sindh, the main cotton-producing provinces of Pakistan, using a portion of the mitochondrial cytochrome oxidase 1 gene. The geographic distribution of the different members of the complex was then compared with the incidence of CLCuD. Using the Dinsdale nomenclature, the results revealed three putative species, Asia 1, Asia II 1 and Middle East-Asia Minor 1. Asia II 1 (also referred to in the literature as biotypes K, P, PCG-1, PK1, SY and ZHJ2) was only recorded from Punjab cotton plants, whereas Asia 1 (also referred to in the literature as biotypes H, M, NA and PCG-2) was found in both Sindh and Punjab. Middle East-Asia Minor 1 (commonly known as biotype B and B2) was found only in Sindh. Moreover, Asia II 1 was associated with high incidences of CLCuD, whereas regions where Middle East-Asia Minor 1 was present had a lower incidence. Phylogenetic analysis showed that the Middle East-Asia Minor 1 population in Sindh formed a distinct genetic subgroup within the putative species, suggesting that the Sindh province of Pakistan may form part of its home range. So far, no individuals from the putative species Mediterranean (commonly known as biotypes Q, J and L) have been found in Pakistan. The capacity to manage pests and disease effectively relies on knowledge of the identity of the agents causing the damage. In the case of CLCuD in Pakistan, this knowledge has been obscured to some extent because of the inconsistent approach to identifying and distinguishing the different B. tabaci associated with CLCuD. The situation has now been clarified, and a strong association between disease

  13. Dificultades metodológicas en la selección de cultivos trampa para el manejo del complejo Bemisia tabaci-virus en tomate

    Directory of Open Access Journals (Sweden)

    Luko Hilje

    2017-05-01

    Full Text Available Se describe la evolución de una metodología para la evaluación de cultivos trampa para el manejo de Bemisia tabaci (biotipo A como vector de virus en tomate, en Costa Rica. Se evaluaron la vainica (Phaseolus vulgaris, Fabaceae, tabaco (Nicotiana tabacum, Solanaceae y berenjena (Solanum melongena, Solanaceae. Aunque los tres cultivos redujeron el impacto del Tomato yellow mottled virus (ToYMoV sobre los rendimientos, el tabaco y la berenjena fueron superiores. No obstante, la extrapolación de estos resultados a condiciones comerciales es compleja, como también lo demuestran las experiencias mundiales, por varias razones que son discutidas.

  14. Transgenic expression of antimicrobial peptide D2A21 confers resistance to diseases incited by Pseudomonas syringae pv. tabaci and Xanthomonas citri, but not Candidatus Liberibacter asiaticus.

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    Guixia Hao

    Full Text Available Citrus Huanglongbing (HLB associated with 'Candidatus Liberibacter asiaticus' (Las and citrus canker disease incited by Xanthomonas citri are the most devastating citrus diseases worldwide. To control citrus HLB and canker disease, we previously screened over forty antimicrobial peptides (AMPs in vitro for their potential application in genetic engineering. D2A21 was one of the most active AMPs against X. citri, Agrobacterium tumefaciens and Sinorhizobium meliloti with low hemolysis activity. Therefore, we conducted this work to assess transgenic expression of D2A21 peptide to achieve citrus resistant to canker and HLB. We generated a construct expressing D2A21 and initially transformed tobacco as a model plant. Transgenic tobacco expressing D2A21 was obtained by Agrobacterium-mediated transformation. Successful transformation and D2A21 expression was confirmed by molecular analysis. We evaluated disease development incited by Pseudomonas syringae pv. tabaci in transgenic tobacco. Transgenic tobacco plants expressing D2A21 showed remarkable disease resistance compared to control plants. Therefore, we performed citrus transformations with the same construct and obtained transgenic Carrizo citrange. Gene integration and gene expression in transgenic plants were determined by PCR and RT-qPCR. Transgenic Carrizo expressing D2A21 showed significant canker resistance while the control plants showed clear canker symptoms following both leaf infiltration and spray inoculation with X. citri 3213. Transgenic Carrizo plants were challenged for HLB evaluation by grafting with Las infected rough lemon buds. Las titer was determined by qPCR in the leaves and roots of transgenic and control plants. However, our results showed that transgenic plants expressing D2A21 did not significantly reduce Las titer compared to control plants. We demonstrated that transgenic expression of D2A21 conferred resistance to diseases incited by P. syringae pv. tabaci and X. citri

  15. Methodology for Developing Life Tables for Sessile Insects in the Field Using the Whitefly, Bemisia tabaci, in Cotton As a Model System.

    Science.gov (United States)

    Naranjo, Steven E; Ellsworth, Peter C

    2017-11-01

    Life tables provide a means of measuring the schedules of birth and death from populations over time. They also can be used to quantify the sources and rates of mortality in populations, which has a variety of applications in ecology, including agricultural ecosystems. Horizontal, or cohort-based, life tables provide for the most direct and accurate method of quantifying vital population rates because they follow a group of individuals in a population from birth to death. Here, protocols are presented for conducting and analyzing cohort-based life tables in the field that takes advantage of the sessile nature of the immature life stages of a global insect pest, Bemisia tabaci. Individual insects are located on the underside of cotton leaves and are marked by drawing a small circle around the insect with a non-toxic pen. This insect can then be observed repeatedly over time with the aid of hand lenses to measure development from one stage to the next and to identify stage-specific causes of death associated with natural and introduced mortality forces. Analyses explain how to correctly measure multiple mortality forces that act contemporaneously within each stage and how to use such data to provide meaningful population dynamic metrics. The method does not directly account for adult survival and reproduction, which limits inference to dynamics of immature stages. An example is presented that focused on measuring the impact of bottom-up (plant quality) and top-down (natural enemies) effects on the mortality dynamics of B. tabaci in the cotton system.

  16. Papaya is not a host for Tomato Yellow Leaf Curl Virus

    Science.gov (United States)

    The economic value of tomato production is threatened by tomato yellow leaf-curl virus TYLCV and its vector, the silverleaf whitefly Bemisia tabaci biotype B (Gennadius) (Hemiptera: Aleyrodidae). Use of papaya Carica papaya L. as a banker plant for a whitefly parasitoid shows promise as a whitefly m...

  17. 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...

  18. 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...

  19. Cloning, expression and characterisation of a novel gene encoding ...

    African Journals Online (AJOL)

    Cloning, expression and characterisation of a novel gene encoding a chemosensory protein from Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) ... The BtabCSP amino acid residues deduced from the respective full-length cDNA shares four conserved cysteine motifs with known CSPs from other insects. Homology ...

  20. Management of sweet potato leaf curl virus in sweetpotatoes using insecticides

    Science.gov (United States)

    Sweetpotato leaf curl virus (SPLCV), which is transmitted by the sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), can severely affect yields of commercial sweetpotatoes, Ipomoea batatas (L.) Lam. (Convolvulaceae). This virus occurs every year at the U.S. Vegetable Laborato...

  1. Óleos vegetais e óleo mineral na mortalidade da Bemisia tabaci biótipo B e na transmissão do vírus do mosaico dourado no feijoeiro

    OpenAIRE

    Marques, Míriam de Almeida

    2011-01-01

    Como alternativa aos inseticidas sintéticos, óleos vegetais e óleos minerais têm se revelado promissores no controle da Bemisia tabaci biótipo B. Esse trabalho teve como objetivo avaliar o efeito de óleos vegetais e mineral sobre ovos, ninfas e adultos da B. tabaci biótipo B e sobre a transmissão do vírus do mosaico dourado no feijoeiro e na sua produtividade. Os experimentos foram conduzidos em casa telada na Embrapa Arroz e Feijão, Santo Antônio de Goiás, Goiás. Utilizaram-se...

  2. Transmissão do Cowpea mild mottle virus pela mosca branca Bemisia tabaci biótipo B para plantas de feijão e soja Transmission of the Cowpea mild mottle virus by whitefly Bemisia tabaci biotype B for plants of beans and soy

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    Julio Massaharu Marubayashi

    2010-06-01

    Full Text Available A necrose da haste da soja é causada por um vírus do gênero Carlavirus transmitido pela mosca branca Bemisia tabaci, também infectante de feijão e identificado como Cowpea mild mottle virus (CpMMV. Neste trabalho foram realizados testes para determinação do número de moscas-brancas B. tabaci biótipo B necessários para transmissão do vírus em feijoeiro e soja. Na sequência foram realizados dois outros testes, com 10 insetos por planta. Avaliaram-se períodos de acesso à aquisição (PAA de 'Jalo' para 'Jalo', e o efeito de períodos de acesso à inoculação (PAI. Foram visualmente constatados sintomas típicos do carlavírus como mosaico, clareamento de nervuras, necrose sistêmica e redução de crescimento. Houve transmissão do vírus para 'BT-2' de feijão e 'BRS-132' de soja com apenas um inseto por planta, sendo mais eficaz nesta última espécie. A taxa de transmissão do vírus foi maior com o aumento do número de insetos por planta. E o PAA foi determinado após 15' de tempo para aquisição, e o PAI com 5 min e aumentando os períodos de acesso a aquisição e inoculação aumentou-se a taxa de transmissão.The stem necrosis of soybean is caused by a virus of the Carlavirus and transmitted for the whitefly Bemisia tabaci, also infectad of beans and identified as Cowpea mild mottle virus (CpMMV. In this work biotype B for transmission of the virus in beans and soy had been carried through tests for determination of the number of necessary whiteflys B. tabaci. In the sequence two other tests had been carried through, with 10 insects for plant. Periods of access to the acquisition (PAA of 'Jalo' for 'Jalo', and the effect of periods of access to the inoculation (PAI had been evaluated increase. Visually typical symptoms of carlavirus had been evidenced as mosaic, veinclearing, sistemic necrosis and reduction of growth. It had transmission of the virus for 'BT-2' of beans and 'BRS-132' of soy with only one insect for plant

  3. No-choice ovipositional nonpreference of Bemisia tabaci (Gennadius B biotype on tomato genotypes Não-preferência para oviposição de Bemisia tabaci (Gennadius biótipo B em genótipos de tomateiro em teste sem chance de escolha

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora de Godoy Oriani

    2011-04-01

    Full Text Available Brazil is one of the main tomato producers worldwide. Nevertheless, 40 to 70% of the production is lost due to Bemisia tabaci (Gennadius B biotype attacks. Resistant plant germplasm can be an important method for controlling this pest in an integrated pest management program. This research aimed to evaluate the no-choice ovipositional preference of B. tabaci B biotype on 18 tomato genotypes with different densities and types of trichomes testing two screening techniques and to determine the influence of trichomes on whitefly ovipositional preference. Two methods of confinement experiments were used. Leaflets detached from the upper third part of the tomato plants (first experiment and 30-day-old plants (second experiment were infested with whiteflies during 24 h. For the first experiment, simple linear correlation tests between the number of insects and eggs, and number of trichomes in the tomato genotypes were carried out. The first technique was better than the second one, as it was easier to carry out and the evaluation demanded less time and as well as was effective to discriminate the resistance level of the evaluated genotypes. Glandular trichomes had a negative correlation with attracted adults and number of eggs deposited, and a positive correlation with number of trapped insects. Negative correlations were observed between number of nonglandular trichomes and trapped insects, and also between total number of trichomes and attracted and trapped insects. Positive correlations were observed between number of total trichomes and eggs cm-2 and nonglandular trichomes and number of eggs. Both confinement methods efficiently discriminated whitefly oviposition among genotypes, especially the resistant ones. High levels of antixenosis for oviposition related to type IV glandular trichomes were exhibited by genotypes LA716, PI134417 and PI134418. The high level of ovipositional preference by B. tabaci for genotypes LA1963 and NAV1062 was related

  4. Transcriptome analysis reveals a comprehensive insect resistance response mechanism in cotton to infestation by the phloem feeding insect Bemisia tabaci (whitefly).

    Science.gov (United States)

    Li, Jianying; Zhu, Lizhen; Hull, J Joe; Liang, Sijia; Daniell, Henry; Jin, Shuangxia; Zhang, Xianlong

    2016-10-01

    The whitefly (Bemisia tabaci) causes tremendous damage to cotton production worldwide. However, very limited information is available about how plants perceive and defend themselves from this destructive pest. In this study, the transcriptomic differences between two cotton cultivars that exhibit either strong resistance (HR) or sensitivity (ZS) to whitefly were compared at different time points (0, 12, 24 and 48 h after infection) using RNA-Seq. Approximately one billion paired-end reads were obtained by Illumina sequencing technology. Gene ontology and KEGG pathway analysis indicated that the cotton transcriptional response to whitefly infestation involves genes encoding protein kinases, transcription factors, metabolite synthesis, and phytohormone signalling. Furthermore, a weighted gene co-expression network constructed from RNA-Seq datasets showed that WRKY40 and copper transport protein are hub genes that may regulate cotton defenses to whitefly infestation. Silencing GhMPK3 by virus-induced gene silencing (VIGS) resulted in suppression of the MPK-WRKY-JA and ET pathways and lead to enhanced whitefly susceptibility, suggesting that the candidate insect resistant genes identified in this RNA-Seq analysis are credible and offer significant utility. Taken together, this study provides comprehensive insights into the cotton defense system to whitefly infestation and has identified several candidate genes for control of phloem-feeding pests. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  5. Cloning and Functional Characterization of c-Jun NH2-Terminal Kinase from the Mediterranean Species of the Whitefly Bemisia tabaci Complex

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    Xiao-Wei Wang

    2013-06-01

    Full Text Available c-Jun NH2-terminal kinase (JNK signaling is a highly conserved pathway that controls gene transcription in response to a wide variety of biological and environmental stresses. In this study, a JNK from the invasive Mediterranean (MED species of the whitefly Bemisia tabaci complex was cloned and characterized. The full-length JNK cDNA of MED consists of 1565 bp, with an 1176 bp open reading frame encoding 392 amino acids. Comparison of JNK amino acid sequences among different species showed that the sequences of JNKs are highly conserved. To reveal its biological function, the gene expression and functional activation of JNK were analyzed during various stress conditions. Quantitative RT-PCR analysis showed that the relative expression level of JNK remained hardly unchanged when the insects were transferred from cotton (a suitable host plant to tobacco (an unsuitable host plant, infected with bacteria and treated with high and low temperatures. However, the mRNA level of JNK significantly increased when treated with fungal pathogens. Furthermore, we found that the amount of phosphorylated JNK increased significantly after fungal infection, while there is no obvious change for phosphorylated p38 and ERK. Our results indicate that the whitefly JNK plays an important role in whitefly’s immune responses to fungal infection.

  6. Insects’ RNA Profiling Reveals Absence of “Hidden Break” in 28S Ribosomal RNA Molecule of Onion Thrips, Thrips tabaci

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    Rosaline Wanjiru Macharia

    2015-01-01

    Full Text Available With an exception of aphids, insects’ 28S rRNA is thought to harbor a “hidden break” which cleaves under denaturing conditions to comigrate with 18S rRNA band to exhibit a degraded appearance on native agarose gels. The degraded appearance confounds determination of RNA integrity in laboratories that rely on gel electrophoresis. To provide guidelines for RNA profiles, RNA from five major insect orders, namely, Diptera, Hemiptera, Thysanoptera, Hymenoptera, and Lepidoptera, was compared under denaturing and nondenaturing conditions. This study confirmed that although present in most of insect’s RNA, the “hidden break” is absent in the 28S rRNA of onion thrips, Thrips tabaci. On the other hand, presence of “hidden break” was depicted in whiteflies’ 28S rRNA despite their evolutionary grouping under same order with aphids. Divergence of 28S rRNA sequences confirms variation of both size and composition of gap region among insect species. However, phylogeny reconstruction does not support speciation as a possible source of the hidden break in insect’s 28S rRNA. In conclusion, we show that RNA from a given insect order does not conform to a particular banding profile and therefore this approach cannot be reliably used to characterize newly discovered species.

  7. Insects' RNA Profiling Reveals Absence of “Hidden Break” in 28S Ribosomal RNA Molecule of Onion Thrips, Thrips tabaci

    Science.gov (United States)

    Macharia, Rosaline Wanjiru; Ombura, Fidelis Levi; Aroko, Erick Onyango

    2015-01-01

    With an exception of aphids, insects' 28S rRNA is thought to harbor a “hidden break” which cleaves under denaturing conditions to comigrate with 18S rRNA band to exhibit a degraded appearance on native agarose gels. The degraded appearance confounds determination of RNA integrity in laboratories that rely on gel electrophoresis. To provide guidelines for RNA profiles, RNA from five major insect orders, namely, Diptera, Hemiptera, Thysanoptera, Hymenoptera, and Lepidoptera, was compared under denaturing and nondenaturing conditions. This study confirmed that although present in most of insect's RNA, the “hidden break” is absent in the 28S rRNA of onion thrips, Thrips tabaci. On the other hand, presence of “hidden break” was depicted in whiteflies' 28S rRNA despite their evolutionary grouping under same order with aphids. Divergence of 28S rRNA sequences confirms variation of both size and composition of gap region among insect species. However, phylogeny reconstruction does not support speciation as a possible source of the hidden break in insect's 28S rRNA. In conclusion, we show that RNA from a given insect order does not conform to a particular banding profile and therefore this approach cannot be reliably used to characterize newly discovered species. PMID:25767721

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

    Science.gov (United States)

    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

  9. 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

  10. Insecticidal activity against Bemisia tabaci biotype B of peel essential oil of Citrus sinensis var. pear and Citrus aurantium cultivated in northeast Brazil.

    Science.gov (United States)

    Ribeiro, Nicolle de Carvalho; da Camara, Claudio Augusto Gomes; Born, Flávia de Souza; de Siqueira, Herbert Alvaro Abreu

    2010-11-01

    The fumigant action of peel essential oils of Citrus sinensis var. pear (pear orange = PO) and C. aurantium (bitter orange = BO) from the northeast of Brazil were evaluated against Bemisia tabaci biotype B and compared with eugenol as a positive control. The oil concentration in the PO at 8.5 microL/L of air caused 97% mortality, while the oil concentration of BO at 9.5 microL/L of air caused 99% mortality. However, the LC50 estimates for both oils (LC50 = 3.80 microL/L of air for PO and LC50 = 5.80 microL/L of air for BO) did not differ from each other, but they did when compared with eugenol (LC50 = 0.20 microL/L of air). Regarding their effects on oviposition, the Citrus oils showed concentration-response dependence, reducing the number of eggs as the concentration increased, which was not observed for eugenol. The minimum concentrations of the oils that caused a significant reduction in the egg lay were 3.5 and 7.0 microL/L of air for BO and PO, respectively. These results suggest that oils from PO and BO peels may be promising as models to develop new insecticides that might be applied into the integrated management of whiteflies.

  11. 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.

  12. 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

    Directory of Open Access Journals (Sweden)

    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.

  13. Interactions of light intensity, insecticide concentration, and time on the efficacy of systemic insecticides in suppressing populations of the sweetpotato whitefly (Hemiptera: Aleyrodidae) and the citrus mealybug (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Cloyd, Raymond A; Williams, Kimberly A; Byrne, Frank J; Kemp, Kenneth E

    2012-04-01

    The impact of light intensity on the uptake and persistence of the systemic neonicotinoid insecticides, imidacloprid and dinotefuran, were evaluated in poinsettia (Euphorbia pulcherrima Willd.) and yellow sage (Lantana camara L.). Insecticide residues were measured in leaves sampled from the treated plants at four time intervals after treatment to determine the relationship between insecticide concentration and efficacy against two insect pests: sweetpotato whitefly, Bemisia tabaci Gennadius, and the citrus mealybug, Planococcus citri Risso. The insecticides were evaluated at their respective label rate and at the comparable label rate of the other insecticide under two different light environments: ambient and shade. The uptake of dinotefuran into yellow sage was more rapid at both treatment rates than both rates of imidacloprid, resulting in higher percent mortality of whitefly nymphs (89.8-100) compared with imidacloprid (14.1-89.2) across all 4 wk. Additionally, plants that received both rates of dinotefuran had fewer whitefly pupae (whitefly nymphs (89.5-99.6) compared with imidacloprid (14.1-89.2) across all 4 wk. However, despite efficient uptake, the efficacy of both systemic insecticides was less for citrus mealybug where percent mortality values were <50% among all the treatments across the 4 wk. The use of the two systemic insecticides evaluated in regards to pest management in horticultural cropping systems is discussed.

  14. Contribution à l'étude de l'écologie et de la biologie des homoptères ravageurs des arbres fruitiers et autres plantes I.- Comparaison de l'évolution des populations d'Aleurodicus dispersus Russell (Hom.: Aleyrodidae sur agrumes et avocatier en République du Congo

    Directory of Open Access Journals (Sweden)

    Kiyindou, A.

    2002-01-01

    Full Text Available Contribution to the Knowledge of the Ecology and Biology of Homopterous Pests of Fruit Trees and other Plants I.- Comparaison of Evolution of Population of Aleurodicus dispersus Russell (Hom.: Aleyrodidae on Citrus and Avocado Trees in the Republic of the Congo. Aleurodicus dispersus Russell, a whitefly of neotropical origin, was introduced into Congo in the early '90. Since 1995, A. dispersus has developped the important populations on Citrus and avocado trees. The study of the population dynamic of this whitefly on Citrus and avocado trees indicates that the pest exhibits only four and three generation a year on Citrus and avocado trees respectively. Besides, an increase of the population of A. dispersus occurs in the dry season. However, rainfall reduces the insect population to a very low level. Its abundance indicates that during the rainy season, A. dispersus appears ealier underpinned for the first time and its significance assessed.

  15. Aqueous extracts and oil of neem combined with neonicotinoid insecticides against Bemisia tabaci biotype B in melon Extratos aquosos e óleo de nim associados com inseticidas neonicotinóides sobre Bemisia tabaci biótipo B em meloeiro

    Directory of Open Access Journals (Sweden)

    Maria Santana de Araújo Trindade

    2007-12-01

    Full Text Available This research was aimed at evaluating nymph population density of whitefly (Bemisia tabaci biotype B in melon plants after treatment with neem-dry-leaf aqueous extracts and neem-oil ( A. Juss. applied alternately with neonicotinoid insecticides under field conditions. The experimental design was a randomized block, with 6 treatments and 4 replications. The treatments were control (only water; neem-dry-leaf extract at 5% (neem-dry-leaf powder 50g L-1 of water; neem oil (5.0mL L-1 water; chemicals insecticides imidacloprid (30g 25L-1 of water and acetamiprid (5g 20L-1 of water; neem-dry-leaf extract at 5% weekly alternated with imidacloprid (30g 25L-1 of water and acetamiprid (5g 20L-1 of water; neem oil (5.0mL L-1 of water weekly alternated with imidacloprid (30g 25L-1 of water and acetamiprid (5g20 L-1 of water. The efficiency of treatments was compared through of the number of nymphs recorded in leaves of melon with 35, and 50 days after planting. The less number of nymphs was registered when the neem oil was applied alternatively with the chemical treatment with efficiency of 28.58 and 7.85% in the first and second evaluations, respectively. However, the nymphs incidence was higher when the neem oil and the chemical treatment were applied separately.O objetivo deste trabalho foi avaliar a densidade populacional de ninfas de mosca-branca (Bemisia tabaci biótipo B em plantas de melão após o tratamento com extratos aquosos de folhas secas de nim e de óleo de nim (Azadiracta indica A. Juss., aplicados alternadamente com inseticidas neonitotinóides, sob condições de campo. O delineamento utilizado foi o de blocos casualizados, com 6 tratamentos e 4 repetições. Foram utilizados os seguintes tratamentos: controle (apenas água; extrato aquoso de folhas secas de nim a 5% (pó de folhas secas de nim, 50 g L-1 de água; óleo de nim (5mL L-1 de água; inseticidas químicos imidacloprid (30g 25L-1 de água e acetamiprid (5g 20L-1 de

  16. Ecology of black pineleaf scale (Homoptera: Diaspididae)

    Energy Technology Data Exchange (ETDEWEB)

    Edmunds, G.F. Jr.

    1973-10-01

    The ecology of black pineleaf scale which occurs on several species of pine and Douglas fir causing defoliation, discoloration of foliage, and reduced growth is reviewed. All known outbreaks of this scale have been caused by reduction in the population of Prosphaltella parasitoid that normally keeps the scale populations at very low densities. Abnormal mortality of Prosphaltella has been found to be caused either by the presence of sorptive dusts or by drift of insecticides. High population densities of scale have been found mainly in areas of high dust fall resulting from industrial sources and roadways. No known causal relationships have been found to exist between atmospheric fluorides and the black pineleaf scale population density. Environmental improvement to conserve the Prosphaltella parasitoids appears to be the most effective control measure.

  17. 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 ...

  18. Morfologia externa dos cicadellinae (homoptera, cicadellidae: comparação entre versigonalia ruficauda (walker (cicadellini e tretogonia cribrata melichar (proconiini, com notas sobre outras espécies e análise da terminologia External morphology of the cicadellinae (homoptera, cicadellidae: comparison between versigonalia ruficauda (walker (cicadellini and tretogonia cribrata melichar (proconiini, with notes on other species and an analysis of the structural terminology

    Directory of Open Access Journals (Sweden)

    Gabriel Mejdalani

    1998-01-01

    Full Text Available The external morphology of two cicadelline species, Versigonalia ruficauda (Walker, 1851 (Cicadellini and Tretogonia cribrata Melichar, 1926 (Proconiini, is analyzed. The head, axillary sclerites, wing venation, female genitalia, and tegumentary processes are described. Notes on other Cicadellini - Amblyscarlidia albofasciata (Walker, 1851, Tettisama quinquemacidata (Germar, 1821, Macugonalia lencomelas (Walker, 1851, and Diedrocephala variegata (Fabricius, 1775 - and Proconiini - Ciccus adspersus (Fabricius, 1803, Homoscarta superciliaris (Jacobi, 1905, Ichthyobelus sp., and Rhaphirrhinus phosphoreus (Linnaeus, 1758 - are added. A technique for dissecting the female genitalia is presented. The facial porlion of head in V. ruficauda, T. cribrata, and remaining species has a large sclerite (frons or postfrontofrons clearly defined by the frontogenal suture. Below the frons, and separated from it by the epistomal suture, a smaller sclerite is present (clypeus. The identification of these sclerites is based on comparisons with descriptions in the literature of a generalized Pterygota, a Psocoptera, a fossil Hemipteroidea, and other Homoptera. The conclusions about the identities of frons and clypeus corroborate the hypotheses of Hamilton (1981 on the homologies of cephalic areas in Rhynchota. The facial sclerites have modifications related with the xyleniomyzous diet. The frons is swollen, providing a larger area for attachmcnt of cibarial muscles. Other modifications increasing the area of frons are observed in the Proconiini. In C. adspersus its lateral margins are distinctly pronounced and its upper portion has a pair of lateral elevations. In Ichthyobelus sp. and R. phosphoreus the upper part of frons is greatly developed, occupying 4/5 of dorsal area of head on middle line. The vertex is limited to a small portion (1/5 of that area. The clypeus is also swollen, a fact related with the greater development of cibarium. This character is more

  19. Transcriptome analysis of the whitefly, Bemisia tabaci MEAM1 during feeding on tomato infected with the crinivirus, Tomato chlorosis virus, identifies a temporal shift in gene expression and differential regulation of novel orphan genes.

    Science.gov (United States)

    Kaur, Navneet; Chen, Wenbo; Zheng, Yi; Hasegawa, Daniel K; Ling, Kai-Shu; Fei, Zhangjun; Wintermantel, William M

    2017-05-11

    Whiteflies threaten agricultural crop production worldwide, are polyphagous in nature, and transmit hundreds of plant viruses. Little is known how whitefly gene expression is altered due to feeding on plants infected with a semipersistently transmitted virus. Tomato chlorosis virus (ToCV; genus Crinivirus, family Closteroviridae) is transmitted by the whitefly (Bemisia tabaci) in a semipersistent manner and infects several globally important agricultural and ornamental crops, including tomato. To determine changes in global gene regulation in whiteflies after feeding on tomato plants infected with a crinivirus (ToCV), comparative transcriptomic analysis was performed using RNA-Seq on whitefly (Bemisia tabaci MEAM1) populations after 24, 48, and 72 h acquisition access periods on either ToCV-infected or uninfected tomatoes. Significant differences in gene expression were detected between whiteflies fed on ToCV-infected tomato and those fed on uninfected tomato among the three feeding time periods: 447 up-regulated and 542 down-regulated at 24 h, 4 up-regulated and 7 down-regulated at 48 h, and 50 up-regulated and 160 down-regulated at 72 h. Analysis revealed differential regulation of genes associated with metabolic pathways, signal transduction, transport and catabolism, receptors, glucose transporters, α-glucosidases, and the uric acid pathway in whiteflies fed on ToCV-infected tomatoes, as well as an abundance of differentially regulated novel orphan genes. Results demonstrate for the first time, a specific and temporally regulated response by the whitefly to feeding on a host plant infected with a semipersistently transmitted virus, and advance the understanding of the whitefly vector-virus interactions that facilitate virus transmission. Whitefly transmission of semipersistent viruses is believed to require specific interactions between the virus and its vector that allow binding of virus particles to factors within whitefly mouthparts. Results provide a

  20. 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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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...

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

    African Journals Online (AJOL)

    1987-07-13

    Jul 13, 1987 ... Tape recordings of calling males were made at various times of day, between October, 1984 and February, ... A sustained noise composed of evenly spaced double pulses. Narrow band sonagrams show a ..... the calls are strictly constrained by the physics of the sound-producing organs, while the temporal ...

  3. Strawberry resistance to the aphid Chaetosiphon fragaefolii Cockerell (Homoptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Slobodan Milenković

    2014-12-01

    Full Text Available Cross-sections of leaf blades and petioles of different strawberry genotypes exhibiting different levels of resistance to Chaetosiphon fragaefolii were studied using the paraffin method, and staining with safranin, crystal violet and light green. Besides thicker cell walls of the cortex collenchyma in the more resistant genotypes, and a proportionally wider collenchyma than parenchyma in the cortex, their midribs are also encircled by a ring of more intensely stained lignified cells forming a physical ring. This stain reaction of cells to safranin and crystal violet occurs also in lateral vascular bundles, as well as in leaf palisade tissue. The tissue cross-sections of the sensitive genotypes revealed a predominance of green on the cellulose cell walls and protoplasts due to the reaction to light green SF, while stain reactions to safranin and crystal violet were not evidenced.

  4. Status Of Cotton Aphid, Aphis gssypiiHomoptera ...

    African Journals Online (AJOL)

    They call for a strict national effort to regulate the influx of pesticides on the market, and ensure safe insecticide types and usage, as well as manage resistance in all concerned major insect pests. Les caractéristiques de répartition en groupes électrophorétiques et les analyses quantitatives de carboxylestérases de l'aphidé ...

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

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    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.

  6. Notes sur les Orgeriini d'Espagne (Homoptera)

    NARCIS (Netherlands)

    Blöte, H.C.

    1957-01-01

    Notre connaissance du groupe des Orgeriini est d'origine récente. La première espèce qu'on a fait la description est Bursinia hemiptera, qui provient d'Italie et qui est décrit comme Fulgora par O. G. Costa en 1840. En 1849 L. Dufour a décrit Dyctiophora longipes et D. genei, étant des espèces qu'on

  7. Range Expansion of Metcalfa pruinosa (Homoptera: Fulgoroidea in Southeastern Europe

    Directory of Open Access Journals (Sweden)

    Cristina Preda

    2011-07-01

    Full Text Available The citrus flatid planthopper Metcalfa pruinosa, a Nearctic species of Fulgoroidea: Flatidae, was accidentally introduced in Europe, first in Italy in the late 1970’s. In a few decades, Metcalfa pruinosa has spread over most of Europe, finally reaching the Black Sea coast in 2009. Hundreds of individuals of different life stages were observed for the first time in the southeastern part of Romania throughout the summer of 2009 on several host plants: Hibiscus syriacus, Ligustrum vulgare, Robinia pseudoacacia, Evonymus japonicus, Spirea x vanhouttei, Aesculus hippocastanum, Philadelphus coronarius, Ficus carica, Vitis vinifera, Fraxinus pennsylvanica. The number of individuals observed and the area covered increased dramatically in 2010 as well as the number of host plants (110 species in 49 families, suggesting the planthopper is in the expansion phase of the invasion process.

  8. Distributional patterns and possible origin of leafhoppers (Homoptera, Cicadellidae

    Directory of Open Access Journals (Sweden)

    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.

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

    African Journals Online (AJOL)

    1987-07-13

    Jul 13, 1987 ... Calling songs were recorded on high quality magnetic tape (Scotch. standard play) at a speed of 38 em/sec ..... by reinforcement. S. Afr. f. Sci. 74: 369-371. PATERSON, H.E. 1985. The recognition concept of species. In: Species and Speciation. Ed. E. Vrba. Transvaal Museum Monograph No.4, TraQsvaal ...

  10. 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

  11. Influence Of Phytolyma lata (Homoptera: Psyllidae) On Seedling ...

    African Journals Online (AJOL)

    Milicia excelsa (Iroko) is a valuable timber species occurring naturally in the humid forests of Africa. The high quality and great demand of wood obtained from M. excelsa has resulted in its overexploitation. Attempts at establishing large scale plantations to ensure sustained production have been hampered by the gall ...

  12. Effects of rearing host species on the host-feeding capacity and parasitism of the whitefly parasitoid Encarsia formosa.

    Science.gov (United States)

    Dai, Peng; Ruan, Changchun; Zang, Liansheng; Wan, Fanghao; Liu, Linzhou

    2014-01-01

    Parasitoids of the Encarsia genus (Hymenoptera: Aphelinidae) are important biological control agents against whiteflies. Some of the species in this genus not only parasitize their hosts, but also kill them through host feeding. The whitefly parasitoid, Encarsia formosa Gahan, was examined to determine whether the rearing host species affects its subsequent host-feeding capacity and parasitism. E. formosa wasps were reared on Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) and Bemisia tabaci (Gennadius) 'Q', and their subsequent host-feeding capacity and parasitism of T. vaporariorum and B. tabaci were examined. E. formosa reared on T. vaporariorum were significantly larger in body size than those reared on B. tabaci, but these wasps killed a similar number of whitefly nymphs by host feeding when they attacked the same host species on which they were reared. Regardless of the species on which it was reared, E. formosa fed significantly more on the B. tabaci nymphs than on the T. vaporariorum nymphs. The number of whitefly nymphs parasitized by E. formosa differed between the wasps reared on T. vaporariorum and those reared on B. tabaci depending on which whitefly species was offered as a host. In addition, the wasps reared on T. vaporariorum parasitized significantly more on T. vaporariorum than those reared on B. tabaci. The wasps reared on B. tabaci, however, parasitized similar numbers of whiteflies of both host species. The results indicated that the host-feeding capacity of E. formosa was affected more by the host species attacked than by the rearing host species, but the parasitism was affected by the host species attacked and the rearing host species. Generally, E. formosa reared on T. vaporariorum killed more T. vaporariorum nymphs by parasitism and host feeding than those reared on B. tabaci. Additionally, a similar number of B. tabaci nymphs were killed by parasitism and host feeding regardless of the rearing host species. Currently

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Contribution to the study of insects (Arthropoda:Insecta associated with the genus Ixora L. (Angiospermae: Rubiaceae in Brazil

    Directory of Open Access Journals (Sweden)

    Thiago Dias Trindade

    2015-08-01

    Full Text Available This study aimed to register insects (Arthropoda: Insecta associated with genus Ixora L. (Angiospermae: Rubiaceae and contribute the knowledge about this popular tropical ornamental plant in Brazil. For this study, we detected the presence of insects in solid or isolated plants of Ixora spp., and greenhouses, between the period 2004 and 2012. It was pointed out for the first time on I. chinensis Lam.: Syntermes dirus (Burmeister, 1839 (Isoptera: Termitidae, Aspidiotus destructor (Signoret, 1869 and Chrysomphalus aonidum (Linnaeus, 1758 (Hemiptera: Diaspididae, Praelongorthezia praelonga (Douglas, 1891 (Hemiptera: Ortheziidae and Camponotus sp. (Hymenoptera: Formicidae. Studies registered for the first time on I. coccinea L.: Aleurothrixus aepim (Goeldi, 1886 and Bemisia tabaci (Gennadius, 1889 (Hemiptera: Aleyrodidae Eucalymnatus sp., Parasaissetia nigra (Nietner, 1861 and Saissetia olae (Olivier, 1791 (Hemiptera: Coccidae, and Camponotus sp. It was observed first on I. macrothyrsa Teijsm. & Binn. N. E. Br.: Aleurothrixus floccosus (Maskell, 1895, Aleurotrachelus sp. (Aleyrodidae, Aphis (Toxoptera citricida (Kirkaldy, 1907 and Myzus (Nectarosiphon persicae (Sulzer, 1778 (Hemiptera: Aphididae Harmonia sp. (Coleoptera: Coccinellidae, Camponotus sp. This paper contributes to the study of these important ornamental plants, presenting for the first time a list of associated insects. This work also creates conditions for future studies.

  15. Transmission of Sweet Potato Leaf Curl Virus by Bemisia tabaci

    Science.gov (United States)

    Sweetpotato, Ipomoea batatas (L.) Lam. (Solanales: Convolvulaceae), is an important world food crop, and Asia is the focal production region. Because it is vegetatively propagated, sweetpotato is especially prone to accumulate infections by several viruses. Sweet potato leaf curl virus (SPLCV) (ss...

  16. siRNA machinery in whitefly (Bemisia tabaci).

    Science.gov (United States)

    Upadhyay, Santosh Kumar; Dixit, Sameer; Sharma, Shailesh; Singh, Harpal; Kumar, Jitesh; Verma, Praveen C; Chandrashekar, K

    2013-01-01

    RNA interference has been emerged as an utmost tool for the control of sap sucking insect pests. Systemic response is necessary to control them in field condition. Whitefly is observed to be more prone to siRNA in recent studies, however the siRNA machinery and mechanism is not well established. To identify the core siRNA machinery, we curated transcriptome data of whitefly from NCBI database. Partial mRNA sequences encoding Dicer2, R2D2, Argonaute2 and Sid1 were identified by tblastn search of homologous sequences from Aphis glycines and Tribolium castaneum. Complete encoding sequences were obtained by RACE, protein sequences derived by Expasy translate tool and confirmed by blastp analysis. Conserved domain search and Prosite-Scan showed similar domain architecture as reported in homologs from related insects. We found helicase, PAZ, RNaseIIIa, RNaseIIIb and double-stranded RNA-binding fold (DSRBF) in Dicer2; DsRBD in R2D2; and PAZ and PIWI domains in Argonaute2. Eleven transmembrane domains were detected in Sid1. Sequence homology and phylogenetic analysis revealed that RNAi machinery of whitefly is close to Aphids. Real-time PCR analysis showed similar expression of these genes in different developmental stages as reported in A. glycines and T. castaneum. Further, the expression level of above genes was quite similar to the housekeeping gene actin. Availability of core siRNA machinery including the Sid1 and their universal expression in reasonable quantity indicated significant response of whitefly towards siRNA. Present report opens the way for controlling whitefly, one of the most destructive crop insect pest.

  17. 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 well in the second year contributing to significant yield improvement against the control. There was no statistically significant difference among treatments in plant height, leaf number and bulb weight. From among ...

  18. Evolution des populations de Bemisia tabaci Genn. selon les ...

    African Journals Online (AJOL)

    Les facteurs climatiques et édaphiques entraînent une forte pression parasitaire qui ..... en dépit du fait que les facteurs climatiques jouent un rôle déterminant dans le fonctionnement de certains écosystèmes ou .... eu des performances assez bonnes et meilleures au niveau de la contamination. L'évolution de la maladie ...

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

    African Journals Online (AJOL)

    ... Mexican marigold (Tagetus minuta L.), tree tobacco (Nicotiana glauca Graham) and Jimson weed (Datura stramonium L.) were tested for their controlling effect on onion thrips. The population dynamics of the thrips was monitored and population counts were made before and after the application of each of the treatments.

  20. 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)

  1. 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

  2. Diet Selection Exhibited by Juvenile and Adult Lifestages of the Omnivores Western Tarnished Plant Bug, Lygus hesperus and Tarnished Plant Bug, Lygus lineolaris

    Science.gov (United States)

    Hagler, James R.; Jackson, C. Glen; Blackmer, Jacquelyn L.

    2010-01-01

    Lygus hesperus Knight and Lygus lineolaris (Palisot de Beauvois) (Heteroptera: Miridae) are economically important plant bugs on many crops worldwide. However, these omnivores are also facultative predators on a wide variety of insects. This study was conducted to quantify and compare herbivory and carnivory exhibited among different lifestages of these two insect pests. The feeding activity of a total of 422 individuals was observed for 1 h each in feeding arenas containing a cotton leaf disk and copious amounts of the sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) eggs, nymphs and adults. The L. hesperus and L. lineolaris lifestages examined included adults and 3rd, 4th and 5th instar nymphs. Plant feeding occupied the majority of both species' time budget, regardless of the species or lifestage examined. There was a tendency for L. lineolaris lifestages to feed more often and for longer duration on plant tissue than L. hesperus. All lifestages of both species rarely fed on B. tabaci, but when they did, they preferred nymphs > adults > eggs. There were only a few cases where there were significant differences in predation rates and prey handling times exhibited among lifestages and between species, but juvenile L. hesperus tended to be more predaceous than juvenile L. lineolaris on whitefly nymphs and adults and 5thinstar and adult L. lineolaris were significantly more herbaceous than their L. hesperus counterparts. In addition, the younger individuals of both species tended to have greater prey handling times than their older counterparts. The significance of these findings is discussed. PMID:20879921

  3. Mitochondrial DNA variability and development of a PCR diagnostic test for populations of the whitefly Bemisia afer (Priesner and Hosny).

    Science.gov (United States)

    Maruthi, M N; Rekha, A R; Sseruwagi, P; Hillocks, R J

    2007-01-01

    The whitefly, Bemisia afer (Hemiptera; Aleyrodidae), is emerging as a major agricultural pest. The current identification methods based on adult and pupal morphology are laborious and unreliable. A diagnostic polymerase chain reaction (PCR) protocol was developed for the first time in this study to discriminate B. afer from other whitefly species. Primers specific to mitochondrial cytochrome oxidase I gene (mtCOI) were designed to amplify a band of approx 650 bp. The PCR products were sequenced from B. afer samples collected from Malawi, Tanzania, Uganda, Zanzibar, and the United Kingdom. Phylogenetic analyses of mtCOI sequences and those of reference B. afer sequences clustered the African B. afer separately from the UK and Chinese populations and from other whitefly species. The African cluster was divided into two clades by parsimony and neighbor-joining methods. This indicates the existence of at least two genotypic clusters of B. afer, which are diverged by 0.8 to 3.2% nucleotide (nt) identities. Analysis of molecular variance indicated that these differences were the result of within population variation but were insufficient to identify discrete populations. Among the whitefly species used in the analysis, B. afer was equally dissimilar to Bemisia tabaci and Bemisia tuberculata (21.3-26.2% nt identities). As is the case for B. tabaci, these data show that mtCOI sequences are informative also for identifying B. afer variants, which lack distinguishing morphological features.

  4. Distributional patterns and possible origins of the tribes and genera of Coelidiinae (Homoptera, Membracoidea, Cicadellidae

    Directory of Open Access Journals (Sweden)

    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.

  5. Comparative biology of three Scymnus lady beetles (Coleoptera: Coccinellidae): predators of Adelges tsugae (Homoptera: Adelgidae)

    Science.gov (United States)

    Wenhua Lu; Michael E. Montgomery

    2000-01-01

    Scymnus (Neopullus) sinuanodulus Yu et Yao, S. (N.) camptodromusYu et Liu, and Scymnus (Neopullus) n. sp. (in press) were collected in the People's Republic of China from hemlocks infested with the hemlock woolly adelgid, Adelges tsugae Annand. To date, 3 of the 14 provinces in China where...

  6. Life Table and Population Parameters of Nasonovia ribisnigri (Homoptera: Aphididae) at different Constant Temperatures

    OpenAIRE

    Díaz Desani, Beatriz M.; Fereres, Alberto

    2005-01-01

    Age-specific life tables of the lettuce aphid, Nasonovia ribisnigri (Mosley), feeding on lettuce were determined at different constant temperatures under controlled conditions. Our results showed that the proportion of alates increased with increasing temperatures, remaining below 7% at 16°C and increasing to 40–57% at a temperature above 20°C. The longest developmental time of apterous aphids was obtained at 8°C (31.5 d), and the shortest was at 26°C (6.2 d), whereas the developmental time o...

  7. 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

  8. [The development of the mycetome in the embryo of Euscelis plebejus Fall. (Homoptera-Cicadina)].

    Science.gov (United States)

    Körner, Helge Klaus

    1969-03-01

    The egg of the leafhopper Euscelis plebejus contains 2 types of symbiontic bacteria classified by MüLLER (1949) as t- and a-symbionts. They are lodged near the posterior egg pole as a nearly spherical mass surrounded by periplasm. During anatrepsis of the germ band the volume of the symbiont mass increases considerably. At the same time the a-symbionts are taken up by primary a-mycetocytes which then form a spherical layer around the as yet extracellular mass of t-symbionts. When the mesoderm of the abdominal segments starts to differentiate into organ primordia, a cluster of presumably polyploid mesoderm cells leaves the 2nd abdominal segment and migrates towards the 5th and 6th abdominal segments where the symbionts are lodged. There these cells are filled with the t-symbionts which they harbour through all further stages of embryonic and postembryonic life. The a-symbionts before katatrepsis of the germ band appear to be taken over by a second type of a-mycetocyte which stems from the genital ridge of the 4th-6th abdominal segments and as a rule is binucleate. During and after katatrepsis the t-mycetocytes and secondary a-mycetocytes migrate from their medial position to the lateral walls of the abdomen where they form one compound mycetome on each side.

  9. Test for intercalary regeneration of the metameric pattern of the leafhopperEuscelis plebejus fall. (homoptera).

    Science.gov (United States)

    Vogel, Otto

    1983-09-01

    Immerging U-shaped germ bands of the leafhopperEuscelis plebejus were cut twice by constriction in order to combine the anterior and posterior ends of the embryo. Although these terminal parts fused in a number of cases, no intercalary regeneration was observed.In addition, the experiments revealed that constriction during anatrepsis (germ anlage extension) causes gaps of varying size in the abdominal part of the segment pattern.The data suggest that "differential adhesion" between yolk cells and the surface of the germ anlage might play a part in the immersion of the germ anlage into the yolk.

  10. Antibiosis and antixenosis to Aphis gossypii (Homoptera: Aphididac) in Colocasia esculenta.

    Science.gov (United States)

    Coleson, Jenifer L; Miller, Ross H

    2005-06-01

    Fifty cultivars of taro, Colocasia esculenta (L.) Schott (Araceae), collected from islands in Micronesia and Polynesia, eight cultivars from the University of Hawaii's taro germplasm collection, and a closely related aroid, Xanthosorna sagittifolium (L.) (Araceae), were screened for antibiosis and antixenosis to Aphis gossypii Clover. Life history data for A. gossypii were collected by assessing survivorship and fecundity of aphids caged on taro leaves in the field. Significant differences in aphid reproductive rate and longevity were observed among the taro cultivars, and cultivars were ranked from most resistant to most susceptible. Antixenosis was assayed in the laboratory in a multiround choice test where A. gossypii were offered four leaf discs excised from different taro cultivars. Additionally, field observations of aphid abundance on taro cultivars were made to corroborate clip cage studies and laboratory experiments. 'Iliuaua','Rumung Mary','Maria', 'Ketan 36', and'Agaga' were the most resistant in terms of reducing aphid fecundity and survivorship, whereas the Iliuana,'Purple', 'TC-83001', and 'Putih 24' were least preferred in aphid choice tests. X. sagittifolium consistently exhibited strong aphid resistance. Resistant cultivars identified in this study may form the basis of breeding programs seeking to combine aphid resistance with other desirable agronomic traits in taro.

  11. General trends of chromosomal evolution in Aphidococca (Insecta, Homoptera, Aphidinea + Coccinea

    Directory of Open Access Journals (Sweden)

    Ilya Gavrilov-Zimin

    2015-07-01

    Full Text Available Parallel trends of chromosomal evolution in Aphidococca are discussed, based on the catalogue of chromosomal numbers and genetic systems of scale insects by Gavrilov (2007 and the new catalogue for aphids provided in the present paper. To date chromosome numbers have been reported for 482 species of scale insects and for 1039 species of aphids, thus respectively comprising about 6% and 24% of the total number of species. Such characters as low modal numbers of chromosomes, heterochromatinization of part of chromosomes, production of only two sperm instead of four from each primary spermatocyte, physiological sex determination, "larval" meiosis, wide distribution of parthenogenesis and chromosomal races are considered as a result of homologous parallel changes of the initial genotype of Aphidococca ancestors. From a cytogenetic point of view, these characters separate Aphidococca from all other groups of Paraneoptera insects and in this sense can be considered as additional taxonomic characters. In contrast to available paleontological data the authors doubt that Coccinea with their very diverse (and partly primitive genetic systems may have originated later then Aphidinea with their very specialised and unified genetic system.

  12. 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.

  13. A review of the leafhopper genus Jikradia with descriptions of four new species (Homoptera: Cicadellidae

    Directory of Open Access Journals (Sweden)

    Carolina Godoy

    1998-09-01

    Full Text Available The genus Jikradia Nielson extends from eastern North America to Central America and the Galapagos Islands. Four additional new species are described and illustrated: J. mexicana (Mexico J. longa (Costa Rica, Guatemala, Mexico, J. zurquiensis (Costa Rica and J. lizanoi (Costa Rica. J. mexicana general color is ochraceous; the aedeagus without seta-like spine. Jikradia longa, general color is light ochraceous; the aedeagus with long seta-like process subapically with three spine-like setae opposite to single subapical seta. Jikradia zurquiensis, general color brown; aedeagus with single seta-like process subapically with three small spine-like setae basad of single subapical setae on the opposite lateral margin of aedeagus. Jikradia lizanoi, general color brown; aedeagus asymmetrical, long, narrow, tube-like, in lateral aspect with sharply pointed apex, with two long seta-like processes subapically with four spine-like setae. A revised key to all known species, and subspecies, based on male genitalia, is also presented.Se describen e ilustran cuatro especies nuevas de Jikradia Nielson: J. mexicana (México J. longa (Costa Rica, Guatemala, México, J. zurquiensis (Costa Rica y J. lizanoi (Costa Rica. El trabajo inlcuye una clave ilustrada para todas las subespecies, con base en los aparatos genitales masculinos.

  14. 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.

  15. TOKSISITAS BEBERAPA HASIL EKSTRAK DAUN TEMBAKAU TERHADAP Myzus persicae (Homoptera;Aphididae

    Directory of Open Access Journals (Sweden)

    - Sudjak

    2015-09-01

    Full Text Available Penggunaan pestisida kimia sintetik yang tidak rasional dapat menyebabkan pencemaran air, tanah, udara, produk pertanian, keracunan manusia/pekerja, resistensi/resurgensi hama, terbunuhnya hewan bermanfaat, perubahan status hama, dan ledakan hama. Untuk itu dirasa perlu mencari pestisida alternatif untuk mendukung pertanian yang berkelanjutan . Melalui kegiatan penelitian yang bertahap telah diperoleh produk pestisida yang diesktrak dari sisa-sisa tanaman tembakau rakyat di lapang yaitu ekstrak 1, ekstrak 2, ekstrak 3, dan ekstrak 4.Kegiatan penelitian ini dilaksanakan di Laboratorium Entomologi Balai Penelitian Tanaman Pemanis dan Serat, Malang mulai bulan Januari sampai dengan Desember 2011.Tujuan penelitian untuk memanfaatkan tembakau sebagai bahan aktif pembuatan pestisida nabati.Untuk tiap-tiap ekstrak di buat lima macam konsentrasi, yaitu 100%, 50%, 25%, 12,5%, 6,25%, 3,125%, dan 0 (kontrol. Serangga uji yang digunakan adalah hama pengisap daun tembakau Myzus persicae. Masing-masing ulangan dengan 20 serangga uji.Data yang diperoleh dari setiap pengamatan dianalisis menggunakan Analisis Probit. Hasil penelitian menunjukkan bahwa empat ekstrak daun tembakau yang diuji terbukti menyebabkan toksisitas pada kutu daun tembakau M. persicae. Ekstrak 3 merupakan ekstrak yang paling toksit dibanding 3 ekstrak yang lain.  LC50 ekstrak 1, ekstrak 2, ekstrak 3, dan ekstrak 4 berturut-turut 35,53%, 26,93%, 5,08%, dan 5,2%. Kata kunci: Ekstrak tembakau, pestisida botani, M. persicae.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Observations of the larval stages of Diceroprocta apache Davis (Homoptera: Tibicinidae)

    Science.gov (United States)

    Ellingson, A.R.; Andersen, D.C.; Kondratieff, B.C.

    2002-01-01

    Diceroprocta apache Davis is a locally abundant cicada in the riparian woodlands of the southwestern United States. While its ecological importance has often been hypothesized, very little is known of its specific life history. This paper presents preliminary information on life history of D. apache from larvae collected in the field at seasonal intervals as well as a smaller number of reared specimens. Morphological development of the fore-femoral comb closely parallels growth through distinct size classes. The data indicate the presence of five larval instars in D. apache. Development times from greenhouse-reared specimens suggest a 3-4 year life span and overlapping broods were present in the field. Sex ratios among pre-emergent larvae suggest the asynchronous emergence of sexes.

  18. The tribe Acutalini Fowler (Homoptera, Membracidae, Smiliinae: new genera, new species and some nomenclatural changes

    Directory of Open Access Journals (Sweden)

    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.

  19. On the taxonomy of Anaceratagallia Zachvatkin, 1946 (Homoptera: Auchenorrhyncha: Cicadellidae: Agalliinae) of Western Kyrgyzstan.

    Science.gov (United States)

    Tishechkin, Dmitri Yu

    2017-06-01

    In Western Kyrgyzstan the genus Anaceratagallia includes four species: A. venosa (de Fourcroy, 1785), A. aciculata (Horvath, 1894), A. laevis (Ribaut, 1935) = A. acuteangulata Dubovskiy, 1966 nec Zachvatkin, 1946, and A. alabugensis Dubovskiy, 1966 = A. collicola Dubovskiy, 1966, syn. n. = A. turanica Dubovskiy, 1966, syn. n. = A. laevis Dubovskiy, 1966 nec Ribaut, 1935. Illustrated descriptions and male calling signal oscillograms for all species are given. The range of A. acuteangulata Zachvatkin, 1946 includes Italy, Greece, Turkey, and North Caucasus; records of this species from Ukraine, Kazakhstan and Central Asia are erroneous. Investigation of morphological and acoustic characters in Anaceratagallia showed that small differences in the shape of male genitalia and 2nd abdominal apodemes are not species-specific traits.

  20. 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...

  1. Duas novas espécies de Tunama fennah, 1968 (Homoptera, Cercopidae

    Directory of Open Access Journals (Sweden)

    Gervásio Silva Carvalho

    1990-01-01

    Full Text Available Two new brazilian species of Tunaima Fennah, 1968 are described: T. brunneoau-rantiaca sp.n. (from São Paulo and Paraná and T. brunneolutea sp.n. (from Paraná and Rio Grande do Sul.

  2. 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

  3. Pauesia decurrens sp. nov. (Hymenoptera: Braconidae), a parasitoid of a Cinara sp. (Homoptera: Aphididae) from California

    Czech Academy of Sciences Publication Activity Database

    Starý, Petr; Zuparko, R. L.

    2005-01-01

    Roč. 81, 3/4 (2005), s. 171-176 ISSN 0031-0603 R&D Projects: GA AV ČR(CZ) IBS5007102 Institutional research plan: CEZ:AV0Z5007907 Keywords : Insecta * Hymenoptera * Braconidae Subject RIV: EG - Zoology Impact factor: 0.308, year: 2005

  4. Effects on the non-target aphid Aphis Gossypii Glover (Homoptera ...

    African Journals Online (AJOL)

    bych76-zhjh77

    2012-05-22

    May 22, 2012 ... parasitoids and their honeydew is an important energy source for several arthropods. Analyses of the impact of transgenic plants expressing Cry toxins on aphids gave variable results ranging from minor negative effects on aphid survival and fecundity to significant beneficial effects on aphid populations ...

  5. Aphids and parasitoids on willows and poplars in southeastern Europe (Homoptera: Aphidoidea; Hymenoptera, Braconidae, Aphidiinae)

    Czech Academy of Sciences Publication Activity Database

    Tomanovic, Ž.; Kavallieratos, N. G.; Starý, Petr; Petrovic-Obradovic, O.; Tomanovic, S.; Jovanović, S.

    2006-01-01

    Roč. 113, č. 4 (2006), s. 174-180 ISSN 1861-3829 R&D Projects: GA AV ČR(CZ) IBS5007102 Grant - others:Ministry of Science and Environmental Protection of the Republic of Serbia(CS) 143006B; Ministry of Science and Environmental Protection of the Republic of Serbia(CS) 145002 Institutional research plan: CEZ:AV0Z50070508 Keywords : agroecosystems * aphids * aphid parasitoid s Subject RIV: EH - Ecology, Behaviour

  6. Areopraon lepelleyi (Waterston) (Hymenoptera: Braconidae: Aphidiinae), a parasitoid of Eriosomatinae (Homoptera: Aphidoidea: Pemphigidae) new to Iran

    Czech Academy of Sciences Publication Activity Database

    Kazemzadeh, S.; Rakhshani, E.; Tomanović, Ž.; Starý, Petr; Petrović, A.

    2009-01-01

    Roč. 14, č. 1 (2009), s. 55-63 ISSN 0354-9410 Grant - others:Ministry of Science and Technological Development of the Republic of Serbia(CS) 143006B Institutional research plan: CEZ:AV0Z50070508 Keywords : Eriosoma lanuginosum * Iran * Areopraon lepelleyi Subject RIV: EG - Zoology

  7. Contact-Induced Emigration of Potato Leafhopper (Homoptera: Cicadellidae) from Alfalfa-Forage Grass Mixtures

    OpenAIRE

    Roda, A. L.; Landis, D. A.; Miller, J. R.

    2017-01-01

    Studies were conducted to evaluate the mechanisms leading to increased potato leafhopper, Empoasca fabae (Harris), emigration from alfalfa-forage grass mixtures. A laboratory behavioral bioassay was used to measure daily emigration rates of adult leafhoppers from alfalfa, Medicago sativa L.; smooth bromegrass, Bromus inermis Leyss.; orchardgrass, Dactylis glomerata L.; and timothy, Phleum pratense L., alone and in 1:1 mixtures of each grass with alfalfa. Emigration was ≍9-fold greater from pu...

  8. 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

  9. The phylogeny and taxonomic status of the Chlorocystini (sensu stricto) (Homoptera, Tibicinidae)

    NARCIS (Netherlands)

    Boer, de A.J.

    1995-01-01

    The “Baeturia and related genera complex”, as defined earlier (De Boer, 1990) by shared aedeagal characters, is identified as the tribe Chlorocystini (sensu stricto). The Prasiini (sensu stricto) are identified as the sister group of the Chlorocystini (sensu stricto), while the genus Muda is

  10. Appearance of cicada fauna (Homoptera: Cicadoidea) by altitudes in Johor National Park, Mount Ledang, Johor

    Science.gov (United States)

    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.

  11. 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

  12. Biology of Scymnus ningshanensis (Coleoptera: Coccinellidae): A predator of Adelges tsugae (Homoptera: Adelgidae)

    Science.gov (United States)

    Michael Montgomery; Hongbin Wang; Defu Yao; Wenhau Lu; Nathan Havill; Guangwu. Li

    2002-01-01

    Information is presented on the occurrence, development, and feeding of Scymnus (Neopullus) ningshanensis Yu et Yao. Information on its biology was collected in the field and laboratory in China and in quarantine in the United States. This lady beetle was found in China only on hemlock infested with ...

  13. Aploneura lentisci (Homoptera: Aphididae and its interactions with fungal endophytes in perennial ryegrass (Lolium perenne

    Directory of Open Access Journals (Sweden)

    Alison Jean Popay

    2016-09-01

    Full Text Available Aploneura lentisci Pass. is endemic to the Mediterranean region where it is holocyclic, forming galls on its primary host, Pistacia lentiscus and alternating over a 2 year period between Pistacia and secondary hosts, principally species of Graminae. This aphid is widely distributed in Australia and New Zealand on the roots of the common forage grasses, ryegrass (Lolium spp. and tall fescue (Schedonorus phoenix where it exists as permanent, anholocyclic, parthenogenetic populations. Previous studies have indicated that infestations of A. lentisci significantly reduce plant growth and may account for differences in field performance of Lolium perenne infected with different strains of the fungal endophyte Epichloë festucae var lolii. These obligate biotrophs protect their host grasses from herbivory via the production of alkaloids. To confirm the hypothesis that growth of L. perenne is associated with the effect of different endophyte strains on aphid populations, herbage and root growth were measured over time in two pot trials that compared three fungal endophyte strains with an endophyte-free control. In both pot trials, aphid numbers were lowest on plants infected with endophyte strain AR37 at all sampling times. In plants infected with a common toxic strain naturalized in New Zealand, aphid numbers overall were lower than on uninfected plants or those infected with strain AR1, but numbers did not always differ significantly from these treatments. Populations on AR1-infected plants were occasionally significantly higher than those on endophyte-free. Cumulative foliar growth was reduced in AR1 and Nil treatments relative to AR37 in association with population differences of A. lentisci in both trials and root dry weight was reduced in one trial. In four Petri dish experiments survival of A. lentisci on plants infected with AR37 declined to low levels after an initial phase of up to 19 days during which time aphids fed and populations were similar to those on plants without endophyte. Aphids on AR37-infected plants became uncoordinated in their movement and developed tremors before dying suggesting a neurotoxin was responsible for their mortality. Results support the hypothesis that differences in A. lentisci populations due to to endophyte infection status and strain affects plant growth.

  14. Ultralow oxygen treatment for postharvest control of Nasonovia ribisnigri (Homoptera: Aphididae) on iceberg lettuce.

    Science.gov (United States)

    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.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Behavior Performance of Diuraphis noxia (Homoptera: Aphididae) on Fungal Endophyte-Infected and Uninfected Perennial Ryegrass

    Science.gov (United States)

    S.L. Clement; D.G. Lester; A. Dan Wilson; K.S. Pike

    1992-01-01

    The behavior and performance of the Russian wheat aphid, Diuraphis noxia (Mordvilko), on fungal endophyte-infected and endophyte-free perennial ryegrass, Lolium perenne L., was investigated in the laboratory and field. Aphids did not select endophyte-free over endophyte-infected leaf sheaths and stem segments in petri dish preference tests....

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Evaluation of the attractive effect of coloured sticky traps for Aleurocanthus spiniferus (Quaintance and its monitoring method in tea garden in China

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2015-12-01

    Full Text Available Aleurocanthus spiniferus (Quaintance, namely tea spiny whitefly (TSW, belongs to the family Aleyrodidae in the order Homoptera, widespread in tea trees and fruit trees in many countries or regions. In this study, the preference of TSW for different colours was evaluated in tea gardens. Yellow was the colour most preferred by TSW, followed by pink, red, white and other colours. The controlling technologies about the number of sticky traps in a certain area of tea garden and the height of sticky traps above tea canopy were also evaluated, the results indicated that the attractive effect of 20 traps/667 m2 of trials area and the height of 10 cm above tea canopy were significantly higher than others treatments. In addition, more TSW was caught at 11:00-15:00, followed by 7:00-11:00, and 15:00-19:00 in a daytime; higher activity level of male adults was at 7:00-11:00 and 11:00-15:00 in day time (95.13% and 94.97% of caught TSW, indicating a higher activity level for male adult.

  20. FECUNDITY OF FICUS WHITEFLY, SINGHIELLA SIMPLEX (HEMIPTERA: ALEYRODIDAE), AND ITS PREDATION BY DELPHASTUS CATALINAE (COLEOPTERA: COCCINELLIDAE)

    Science.gov (United States)

    Ficus Whitefly (Singhiella simplex) was first reported in Miami-Dade County in August 2007. This invasive pest causes infested plants to exhibit leaf yellowing, followed by leaf drop. The pest has been recorded on multiple ficus hosts including Ficus benjamina, F. altissima, F. bengalensis, F. micro...

  1. Repellency, toxicity, and oviposition inhibition of vegetable extracts against greenhouse whitefly Trialeurodes vaporariorum (Westwood (Hemiptera: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Edgar Eduardo Mendoza-Garcia

    2014-03-01

    Full Text Available In a search for sustainable options of greenhouse whitefly Trialeurodes vaporariorum (Westwood management, the toxic and/or repellent potential of water, ethanolic, and acetonic extracts of Ambrosia artemisiifolia L. (Asteraceae, Comocladia engleriana Loes (Anacardiaceae, Piper auritum Kunth (Piperaceae, Raphanus raphanistrum L. (Brassicaceae, and Taraxacum officinale F.H. Wigg. aggr.* (Asteraceae were evaluated. Repellency was assessed by the cylinder method (olfactometer, while toxicity and oviposition inhibition were assessed by the leaf immersion method. Acetonic extracts did not cause any repellent or insecticidal effect. In contrast, 200 mg mL-1 water and ethanolic extracts of R. raphanistrum and ethanolic extract of A. artemisiifolia had the highest repellent activity (76%, 72%, and 69%, respectively although their activity decreased gradually over time. Ethanolic extracts of P. auritum (66% and R. raphanistrum (56% at 200 mg mL¹ were highlighted as being toxic, while the most effective in inhibiting oviposition were water extracts of R. raphanistrum (76.1% and P. auritum (72.0% and ethanolic extract of P. auritum (69.5%; however, concentrations lower than 60 mg mL-1 caused oviposition stimulation. Our results suggest that water and ethanolic extracts of R. raphanistrum and P. auritum represent a useful tool in integrated whitefly management.

  2. REPRODUCTION OF THE FICUS WHITEFLY, SINGHIELLA SIMPLEX (HEMIPTERA: ALEYRODIDAE): A NEW INVASIVE PEST IN THE USA

    Science.gov (United States)

    Ficus Whitefly (Singhiella simplex) was first reported in Miami-Dade County in August 2007. This invasive pest causes infested plants to exhibit leaf yellowing, followed by leaf drop. The pest has been recorded on multiple ficus hosts including Ficus benjamina, F. altissima, F. bengalensis, F. micro...

  3. Siphoninus finitimus Silvestri (Hemiptera: Aleyrodidae), "mosquita blanca del olivo" en Arica-Chile

    OpenAIRE

    Bobadilla Guzman, Dante; Cerdá Hernández, Carolina; Salvatierra Martínez, Ricardo; Sepúlveda Chavera, Germán F.

    2014-01-01

    Se ent regan antecedentes sobr e las diferencias morfométricas en distintas estructuras de adultos y del pupoide de las poblaciones de aleyródidos asociados a olivo, peral y granado en la región de Arica- Parinacota, Chile. Las significativas diferencias (p < 0,01) encontradas en las dimensiones y en la morfología de las estructuras estudiadas entre las distintas poblaciones de mosquitas blancas que a...

  4. 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...

  5. [Occurrence of Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) in the state of Maranhão, Brazil].

    Science.gov (United States)

    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.

  6. 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)

  7. 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

    Directory of Open Access Journals (Sweden)

    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

  8. 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

  9. Diversity and localization of bacterial endosymbionts from whitefly species collected in Brazil.

    Science.gov (United States)

    Marubayashi, Julio Massaharu; Kliot, Adi; Yuki, Valdir Atsushi; Rezende, Jorge Alberto Marques; Krause-Sakate, Renate; Pavan, Marcelo Agenor; Ghanim, Murad

    2014-01-01

    Whiteflies (Hemiptera: Aleyrodidae) are sap-sucking insect pests, and some cause serious damage in agricultural crops by direct feeding and by transmitting plant viruses. Whiteflies maintain close associations with bacterial endosymbionts that can significantly influence their biology. All whitefly species harbor a primary endosymbiont, and a diverse array of secondary endosymbionts. In this study, we surveyed 34 whitefly populations collected from the states of Sao Paulo, Bahia, Minas Gerais and Parana in Brazil, for species identification and for infection with secondary endosymbionts. Sequencing the mitochondrial Cytochrome Oxidase I gene revealed the existence of five whitefly species: The sweetpotato whitefly Bemisia tabaci B biotype (recently termed Middle East-Asia Minor 1 or MEAM1), the greenhouse whitefly Trialeurodes vaporariorum, B. tabaci A biotype (recently termed New World 2 or NW2) collected only from Euphorbia, the Acacia whitefly Tetraleurodes acaciae and Bemisia tuberculata both were detected only on cassava. Sequencing rRNA genes showed that Hamiltonella and Rickettsia were highly prevalent in all MEAM1 populations, while Cardinium was close to fixation in only three populations. Surprisingly, some MEAM1 individuals and one NW2 population were infected with Fritschea. Arsenopnohus was the only endosymbiont detected in T. vaporariorum. In T. acaciae and B. tuberculata populations collected from cassava, Wolbachia was fixed in B. tuberculata and was highly prevalent in T. acaciae. Interestingly, while B. tuberculata was additionally infected with Arsenophonus, T. acaciae was infected with Cardinium and Fritschea. Fluorescence in situ hybridization analysis on representative individuals showed that Hamiltonella, Arsenopnohus and Fritschea were localized inside the bacteriome, Cardinium and Wolbachia exhibited dual localization patterns inside and outside the bacteriome, and Rickettsia showed strict localization outside the bacteriome. This study is

  10. Validation of a Landscape-Based Model for Whitefly Spread of the Cucurbit Yellow Stunting Disorder Virus to Fall Melons.

    Science.gov (United States)

    Carrière, Yves; Degain, Ben; Liesner, Leighton; Dutilleul, Pierre; Palumbo, John C

    2017-10-01

    The cucurbit yellow stunting disorder virus (CYSDV) transmitted by Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) has caused significant reductions in fall melon (Cucumis melo L.) yields in Yuma County, Arizona. In a recent landscape-based study, we found evidence that cotton and spring melon fields increased abundance of B. tabaci and spread of CYSDV infection in fall melon fields. Here, we show that a statistical model derived from data collected in 2011-2012 and based on areas of cotton and spring melon fields located within 1,500 m from edges of fall melon fields was sufficient to retrospectively predict incidence of CYSDV infection in fall melon fields during 2007-2010. Nevertheless, the slope of the association between areas of spring melon fields and incidence of CYSDV infection was three times smaller in 2007-2010 than in 2011-2012, whereas the slope of the association between areas of cotton fields and incidence of CYSDV infection was consistent between study periods. Accordingly, predictions were more accurate when data on areas of cotton alone were used as a basis for prediction than when data on areas of cotton and spring melons were used. Validation of this statistical model confirms that crop isolation has potential for reducing incidence of CYSDV infection in fall melon fields in Yuma County, although isolation from cotton may provide more consistent benefits than isolation from spring melon. © 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.

  11. 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.

  12. 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

    Directory of Open Access Journals (Sweden)

    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.

  13. Effect of sugar beet root aphid, Pemphigus fuscicornis (Homoptera: Pemphigidae), on sugar beet yield and quality in Iran.

    Science.gov (United States)

    Zarrabi, M

    2007-10-01

    Pemphigus fuscicornis (Koch) is a pest of sugar beet root in warm and dry regions of Iran. This belongs to the Middle East and south east of Asia fauna. Nymphs establish colonies in root sutures and feed heavily which cause wilting and yellowing in beet near harvest. This study was conducted to determine infestation indices, damage occurrence and the necessity for control measures of this pest. Nymph colonies were monitored in different experimental fields that were planted with commonly used monogerm variety Afshari and then five infested places were selected. Damaged root specimens were sampled from five foci and ranked for infestation, yield and sugar concentration. Results indicated that there were no significant differences in weight, sugar concentration and impurities between indices 1, 2, 3 and none infested beets. Only the sugar concentration of indices 4 showed significant differences with zero infested beets. In the other hand, no specimens were found with the highest population density index (indices 5). Therefore, the sugar beet root aphid populations did not reach to the level of economic damage in these experimental fields. Thus, the control measures such as chemical application and use of resistant varieties may be used when the colonies density increases to the indices four and five throughout the foci in such fields.

  14. Comparison of AC electronic monitoring and field data for estimating tolerance to Empoasca kraemeri (Homoptera: Cicadellidae) in common bean genotypes.

    Science.gov (United States)

    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.

  15. 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.

  16. 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)

  17. The taxonomy and biogeography of the bloetei group of the genus Baetura Stål, 1866 (Homoptera, Tibicinidae)

    NARCIS (Netherlands)

    Boer, de A.J.

    1989-01-01

    The bloetei group is proposed for a monophyletic group of 18 species of the genus Baeturia Stål, 1866. Fifteen species are described as new ( B. bilebanarai, B. bismarckensis, B. bloetei, B. boulardi, B. brandti, B. cristovalensis, B. gressitti, B. macgillavryi, B. manusensis, B. marginata, B.

  18. Tanggap fungsional Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae terhadap Aphis gossypii (Glover (Homoptera: Aphididae pada umur tanaman cabai berbeda

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    Novri Nelly

    2015-09-01

    Full Text Available The lady beetle, Menochilus sexmaculatus is one of the biological control agents that can be used to control aphids. Presently, there is a lack of information about the effectiveness of this beetle to control aphids. The objective of this research was to study the functional response of M. sexmaculatus on Aphis gossypii at different ages of plants. All preys were exposed to one M. sexmaculatus adult for an hour at five different densities of aphids (10, 20, 30, 40, and 50 individuals is four different ages of chilli plants (2,4,6, and 8 weeks. Data were analyzed by ANOVA and logistic regression to determine the type of functional response. The results showed that the ability of M. sexmaculatus to prey was not significant at 2 to 4 and 6 to 8 weeks old chilli plants. At 2 week old chilli plants M. sexmaculatus showed type I of functional response, while at 4, 6 and 8 weeks the functional response were type III.

  19. Performance of novel vs traditional insecticides for the control of amrascs biguttula biguttula (homoptera, cicadellidae) on cotton

    International Nuclear Information System (INIS)

    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)

  20. Bacterial symbionts, Buchnera, and starvation on wing dimorphism in English grain aphid, Sitobion avenae (F.) (Homoptera: Aphididae)

    Science.gov (United States)

    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). Virtually al...

  1. Pattern formation in longitudinal halves of leaf hopper eggs (Homoptera) and some remarks on the definition of "Embryonic regulation".

    Science.gov (United States)

    Sander, Klaus

    1971-12-01

    1. Eggs of the leaf hopperEuscelis plebejus F. were fragmented longitudinally by a novel technique during cleavage. 2. Irrespective of the plane of fragmentation, both fragments may produce germ bands which are either of perfect bilateral symmetry or contain at least some bilaterally symmetrical body segments. With one possible exception, no longitudinal half-patterns were formed. 3. Ventral and lateral egg halves produce either complete germ bands or anterior partial germ bands. The failure to produce posterior body segments is correlated to the absence of special posterior pole materials marked by the symbiont mass. 4. Dorsal egg halves may produce either complete germ bands or posterior partial germ bands. The loss of anterior segments may be due to lack of keimanlagen cells. 5. The results are discussed and compared to those from transverse fragmentations carried out earlier. 6. Aided by a formalized presentation of the results a dilemma of definition is pointed out which results from the common usage of defining embryonic regulation as the alternative of mosaic development and at the same time by reference to the normal result of development.

  2. Varietals resistance and susceptibility in mustard (brassica campestris l.) genotypes against aphid myzus persicae (sulzer) (homoptera: aphididae)

    International Nuclear Information System (INIS)

    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)

  3. Comparative profiling of microRNAs in the winged and wingless English grain aphid, Sitobion avenae (F.) (Homoptera: Aphididae)

    Science.gov (United States)

    English green aphid, Sitobion avenae (F.), show a classic polyphenic wing dimorphism among isogenic adults that is an intriguing model for the study of morphological plasticity in response to the environment. Short non-coding microRNA (miRNA) molecules regulate gene expression by post-transcriptiona...

  4. A redescription of Puto antennatus Sign. (Homoptera, Coccoidea) with notes on Ceroputo pilosellae Šulc and Macrocerococcus superbus Leon.

    NARCIS (Netherlands)

    Reyne, A.

    1954-01-01

    In the taxonomy of Coccoidea or scale insects much confusion is due to an insufficient knowledge of the type species of several genera. Especially our knowledge of some of the older genera is very incomplete, as the descriptions of their type species are extremely short and superficial from the

  5. Parasitism and predation of the planthopper Tagosodes orizicolus (Homoptera: Delphacidae by a dryinid parasitoid in Costa Rica

    Directory of Open Access Journals (Sweden)

    Floria Mora-Kepfer

    2009-11-01

    Full Text Available We analyzed the effect of predation and parasitism by the native dryinid Haplogonatopus hernandezae as a natural enemy of the rice pest Tagosodes orizicolus under controlled conditions in an insectary in Costa Rica. We found no change in the proportion of T. orizicolus nymphs that were fed upon, parasitized, and that showed no apparent damage throughout the adult stage in H. hernandezae, which favors a stable control of the pest. The percentage of T. orizicolus nymphs that were parasitized (37 % and preyed upon (36.5 % was similar, eliminating 73,5 % of the total nymphs causing damage to the rice plants (N = 1 099. Of the total 324 parasitized nymphs, female nymphs were more parasitized than male nymphs (95 % and 5 % respectively and dryinids developed more successfully in female host nymphs. These tendencies did not change with dryinid age. Survival of dryinids was higher in female T. orizicolus, both for larvae that emerged from the host and pupated, and for pupae that moulted to adults. In cages where the nymphs had no contact with dryinids we found a higher amount of males than females (57.44 ± 28.5 vs 45.22 ± 25.85. In contrast, when the nymphs were in contact with dryinids, the sex ratio was two females to one male reaching adulthood since the dryinids fed more on male nymphs (N = 692. Our results indicate that female dryinids prefer to oviposit in female T. orizicolus nymphs and prey on males. Reproduction by parthenogenesis, acceleration of the development in an insectary with controlled conditions and eficiency of H. hernandezae as a parasitoid and predator indicate that this dryinid is an effective biological control agent of T. orizicolus. Rev. Biol. Trop. 57 (Suppl. 1: 203-211. Epub 2009 November 30.

  6. CONTROLE QUÍMICO DO PULGÃO MYZUS PERSICAE (SULZER,1776 (HOMOPTERA-APHIDIDAE NA CULTURA DO FUMO

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    Manoel Fernando Sigaran Tarragó

    1994-01-01

    Full Text Available RESUMO Estudou-se a ação de diferentes inseticidas sobre populações do pulgão, Myzus persicae, em lavouras de fumo da Agro Comercial Fumageira S. A., var. Sumatra, no Município de Cruz das Almas - BA. Foram realizados dois ensaios, um em dezembro de 1991 e o outro em fevereiro de 1992, e nas duas oportunidades mostraram-se eficientes os inseticidas Acefate 750 PS, Pirimicarb 500 PM e Metamidofos 600 CE.

  7. Resistance of Endophyte-Infected Plants of Tall Fescue and Perennial Ryegrass to the Russian Wheat Aphid (Homoptera: Aphididae)

    Science.gov (United States)

    S.L. Clement; K.S. Pike; W.J. Kaiser; A. Dan Wilson

    1991-01-01

    Fewer aphids of the Russian wheat aphid, (Mordvilko), were found on tall fescue and perennial ryegrass plants harboring systemic fungal endophytes than on endophyte-free plants in laboratory tests. These results indicate that enhanced resistance in some perennial grasses to D. noxia is associated with the presence of endophytic fungi.

  8. Guineapsaltria, a new genus from the Australian — New Guinean region (Homoptera, Tibicinidae), with notes on its taxonomy and biogeography

    NARCIS (Netherlands)

    Boer, de A.J.

    1993-01-01

    The genus Guineapsaltria is erected for eight species, distributed in New Guinea and northeastern Queensland. Five species are transferred from the genus Baeturia Stål, 1866 and redescribed, viz. G. chinai (Blöte, 1960), G. flava (Goding & Froggatt, 1904), G. pallida (Blöte, 1960), G. stylata

  9. Chemical Composition and Behavioral Effects of Five Plant Essential Oils on the Green Pea Aphid Acyrthosiphon pisum (Harris) (Homoptera: Aphididae).

    Science.gov (United States)

    Kasmi, Abir; Hammami, Majdi; Raoelison, Emmanuel G; Abderrabba, Manef; Bouajila, Jalloul; Ducamp, Christine

    2017-05-01

    Essential oils (EOs) from Schinus molle, Helichrysum gymnocephalum, Cedrelopsis grevei and Melaleuca viridiflora, four aromatic and medicinal plants, are commonly used in folk medicine. EOs were characterized by gas chromatography/mass spectrometry (GC/MS) and quantified by gas chromatography-flame ionization detection (GC-FID); then evaluated for their behavioral effects on adults of the green pea aphid Acyrthosiphon pisum (Harris) using a Perspex four-armed olfactometer in order to test the compatibility of their use as phytoinsecticides to control this insect pest. Our results showed that the EOs from the leaves of S. molle, M. viridiflora and C. grevei did not change aphids' behavior. However, S. molle fruits EO seemed to be attractive while H. gymnocephalum leaves EO exhibited repellency towards aphids at a dose of 10 μl. The major compounds in S. molle fruits EO were 6-epi-shyobunol (16.22%) and d-limonene (15.35%). While, in H. gymnocephalum leaves EO, 1,8-cineole was the main compound (47.4%). The difference in aphids' responses to these two EOs could be attributed to the differences in their compositions. Our findings suggest that these two EOs have potential applications for the integrated pest management of A. pisum (Harris). © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  10. Aphids (Homoptera, Aphidodea inhabiting the trees Crataegus x media Bechst. in the urban green area. Part I. The population dynamics

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    Bożena Jaśkiwicz

    2013-12-01

    Full Text Available The studies were conducted in the years 1999-2001 in the green areas of Lublin, on the trees of Crataegus x media Bechst. The purpose of the studies was to establish the species composition and the population dynamics of aphids inhabiting hawthorn in the street and park sites. The studies found out the presence of four aphid species on the examined trees, namely Aphis pomi De Geer, aphids from the genus Dysaphis Börn., Ovatus crataegarius (Walk. and Rhopalosiphum insertum (Walk.. More aphid species and bigger populations were found in the street site (A as compa red with the park site (B.The weather conditions (air temperatures of over 30°C and stormy rainfalls limited the population of all aphid species. On the other hand, a mild winter and a warm spring with the rainfalls within the norm caused that the number of aphids decreased considerably.

  11. Clonal turnover of MACE-carrying peach-potato aphids (Myzus persicae (Sulzer), Homoptera: Aphididae) colonizing Scotland.

    Science.gov (United States)

    Kasprowicz, L; Malloch, G; Foster, S; Pickup, J; Zhan, J; Fenton, B

    2008-04-01

    Peach-potato aphids, Myzus persicae (Sulzer), collected in Scotland in the years 1995 and 2002-2004 were characterized using four microsatellite loci and three insecticide resistance mechanisms. From 868 samples, 14 multilocus genotypes were defined (designated clones A-N). Five of these (denoted A, B, H, M and N) carried modified acetylcholinesterase (MACE) resistance, the most recent resistance mechanism to have evolved in M. persicae. The current paper shows that the continued presence of MACE aphids is due to turnover, as clones A and B were replaced in field samples by clones H, M and N in later seasons. Thus, insecticide-resistant populations in Scotland can be attributed to multiple waves of rapid clone colonisations and not to the continued presence of stable resistant clones or mutation or sexual recombination in local populations. The MACE clones carried varying levels of the other insecticide resistance mechanisms, kdr and esterase. The presence of these mechanisms could alter the clones success in the field depending on insecticide spraying (positive selection) and resistance fitness costs (negative selection).

  12. Pear transformed with a lytic peptide gene for disease control affects nontarget organism, pear psylla (Homoptera: Psyllidae).

    Science.gov (United States)

    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.

  13. Bacterial symbionts, Buchnera, and starvation on wing dimorphism in English grain aphid, Sitobion avenae (F. (Homoptera: Aphididae

    Directory of Open Access Journals (Sweden)

    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.

  14. A new species of Aphidius Nees, 1818 (Hymenoptera, Braconidae, Aphidiinae) attacking Uroleucon aphids (Homoptera, Aphididae) from Iran and Iraq

    Czech Academy of Sciences Publication Activity Database

    Rakhshani, E.; Talebi, A. A.; Starý, Petr; Tomanovic, Ž.; Manzari, S.; Kavallieratos, N. G.; Cetkovic, A.

    2006-01-01

    Roč. 40, 32-34 (2006), s. 1923-1929 ISSN 0022-2933 R&D Projects: GA AV ČR(CZ) IBS5007102 Grant - others:The Ministry of Science and Environmental Protection of the Republic of Serbia(CS) 143006 Institutional research plan: CEZ:AV0Z50070508 Keywords : Aphidiinae * Aphidius * Iran Subject RIV: EG - Zoology Impact factor: 0.631, year: 2006

  15. A contribution to the taxonomy, cytogenetics and reproductive biology of the genus Aclerda Signoret (Homoptera, Coccinea, Aclerdidae

    Directory of Open Access Journals (Sweden)

    Ilya Gavrilov-Zimin

    2012-11-01

    Full Text Available A new species of scale insects, Aclerda pseudozoysiae sp. n., is described and illustrated. The karyotypes and some aspects of reproductive biology and cytogenetics of the new species species and Aclerda takahashii Kuwana, 1932 were studied, representing the first data for the genus Aclerda Signoret, 1874 and the family Aclerdidae as a whole. A. pseudozoysiae sp. n. has 2n=16, bisexual reproduction, and heterochromatinization of one haploid set of chromosomes in male stages of the life cycle, matching either a Lecanoid or a Comstockioid genetic system. A. takahashii demonstrates 2n=18 and unusual type of parthenogenesis with diploid and haploid embryos (inside each gravid female without heterochromatinization. Both species are ovoviviparous; all stages of embryonic development occur inside the mother’s body.

  16. Lady beetles (Coleoptera: Coccinellidae) from Chinese hemlocks infested with the hemlock woolly adelgid, Adelges tsugae Annand (Homoptera: Adelgidae)

    Science.gov (United States)

    Gouyue Yu; Michael E. Montgomery; Defu Yao

    2000-01-01

    Fifty-four species of lady beetles were collected from three Chinese hemlock species, Tsuga dumosa (D. Don) Eichler, T. forrestii Downie and T. chinensis (Franchet) Pritzel, in Yunnan, Sichuan and Shaanxi provinces of China as part of a search for natural enemies of the hemlock woolly adelgid, Adelges tsugae Annand. Twenty new species are described: Clitostethus...

  17. The environmental plasticity of diverse body color caused by extremely long photoperiods and high temperature in Saccharosydne procerus (Homoptera: Delphacidae

    Directory of Open Access Journals (Sweden)

    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.

  18. Interplant movement and spatial distribution of alate and apterous morphs of Nasonovia ribisnigri (Homoptera: Aphididae) on lettuce.

    Science.gov (United States)

    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.

  19. 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.

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

    Indian Academy of Sciences (India)

    The siRNAs were recovered by precipitation with ethanol, dissolved in water and analysed on 15% native polyacrylamide gel. 3. Results. 3.1 Selection ..... insecticidal Photorhabdus luminescens toxin complex a (Tca):. Activity against the Colorado potato beetle, Leptinotarsa. 160. Santosh Kumar Upadhyay et al. J. Biosci.