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Sample records for bemisia tabaci gennadius

  1. HOST PLANT PREFERENCES OF BEMISIA TABACI GENNADIUS

    Institute of Scientific and Technical Information of China (English)

    JINGYing; HUANGJian; MARui-yan; HANJu-cai

    2003-01-01

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

  2. Extraordinary resistance to insecticides reveals exotic Q biotype of Bemisia tabaci (Gennadius) in the New World

    Science.gov (United States)

    The whitefly Bemisia tabaci (Gennadius) possessing unusually high levels of resistance to a wide range of insecticides were discovered in 2004 in the course of routine resistance monitoring in Arizona. The multiply-resistant insects, collected from poinsettia (Euphorbia pulcherrima) plants purchased...

  3. Characterization and Comparative Profiling of miRNAs in Invasive Bemisia tabaci (Gennadius) B and Q

    OpenAIRE

    Guo, Qiang; Tao, Yun-Li; Chu, Dong

    2013-01-01

    Background MicroRNAs (miRNAs) are small, conserved, non-coding RNAs that post-transcriptionally regulate gene expression. Bemisia tabaci (Gennadius) B and Q are two invasive and dominant whiteflies, and B. tabaci Q has been displacing B in China. Differences in biological traits (fecundity, host range, resistance to insecticides, etc.) as affected by miRNAs might be involved in the displacement. In this study, we performed high-throughput sequencing to identify miRNAs in B. tabaci B and Q. Re...

  4. Resistencia a insecticidas en Bemisia tabaci (Gennadius): nivel de resistencia, resistencias cruzadas y mecanismosimplicados

    OpenAIRE

    Fernández García, María Esther

    2013-01-01

    [SPA] La mosca blanca del tabaco, Bemisia tabaci (Gennadius, 1889), desde la década de los 90 es una de las plagas más importantes de muchos cultivos hortícolas y ornamentales españoles, tanto por sus daños directos como por la aparición de virus transmitidos por este insecto. A lo largo de estos años el uso excesivo de insecticidas para su control ha hecho que esta plaga desarrolle resistencias a diversos grupos de insecticidas. Para evitar esto y poder plantear estrategias de control adecua...

  5. Genetic Differentiation of Different Geographical Populations of Bemisia tabaci (Gennadius) Complex

    Institute of Scientific and Technical Information of China (English)

    CHU Dong; LIU Guo-xia; FAN Zhong-xue; TAO Yun-li; ZHANG You-jun

    2007-01-01

    Bemisia tabaci (Gennadius) is a species complex, which includes different geographical populations with genetic differentiation. The recent progress on the genetic differentiation of various geographical populations of B. tabaci complex was introduced. The genetic differentiation was further analyzed on the basis of the sequences of mtDNA COI and rDNA ITSl recorded in the world's GenBank. Five groups are defined on the basis of mtDNA COI and rDNA ITS1, including the Asia group, America group, Africa group, Australia group, and Biotype B/Mediterranean/Middle East/ Northern Africa/Biotype Ms group. There are several ungrouped geographical classifications, such as the Uganda population, Ivory Coast population, and Taiwan population. Geographical isolation may be the most important factor that contributed to the genetic differentiation of various geographical populations of B. tabaci. Many populations with biological advantages invaded new regions and caused severe economic losses within human activity. It is necessary to strengthen the research of B. tabaci biotype to prevent the spread of invaded populations and the invasion of potentially dangerous populations.

  6. Study on species composition of Bemisia tabaci (Gennadius, 1889) (Hemiptera: Aleyrodidae) on cotton in Çukurova plain, Turkey

    OpenAIRE

    KARUT, Kamil; Kaydan,M. Bora; CASTLE, Steven J.; KAZAK, Cengiz; ULUSOY, M. Rifat

    2014-01-01

    The whitefly Bemisia tabaci (Gennadius, 1889) (Hemiptera: Aleyrodidae) is one of the most important pest species on cotton in the Çukurova Plain as well as in all cotton growing areas of Turkey. Although numerous studies on population dynamics, population development and parasitism were conducted on B. tabaci in the Çukurova Plain, there has been a few studies on the species complex of B. tabaci for this region. The aims of this study were to present genetic polymorphism and species compositi...

  7. MORPHOMETRICS OF BEMISIA TABACI (GENNADIUS (HEMIPTERA: ALEYRODIDAE SPECIES COMPLEX FROM COTTON

    Directory of Open Access Journals (Sweden)

    ASHA THOMAS

    2016-09-01

    Full Text Available The whitefly Bemisia tabaci (Gennadius is now recognized as a species complex and many of its genetic groups are important agricultural pests. B. tabaci specimens collected from three cotton cultivars were subjected to genetic characterization and morphometric studies. The cotton cultivars selected were namely HS1300, P86 and LRA5166. Genetic diversity in the populations using mitochondrial cytochrome oxidase 1 (mtCO-1 sequences revealed the presence of three genetic groups namely Asia 1, Asia II 1 and Asia II 7 groups. For morphometrics, 62 morphological characters on puparia were considered. The principal component analysis revealed a wide range of morphological variations in the critical taxonomic characters among the populations. Contrastingly, puparial length was more in Asia II 1 genetic group whereas breadth of puparia, length of antenna, lingula and vasiform orifice were more in Asia I genetic group. Thus, this study adds to our knowledge of the host-associated morphological variations and genetic diversity of B. tabaci populations.

  8. Relative amount of symbionts in Bemisia tabaci (Gennadius) Q changes with host plant and establishing the method of analyzing free amino acid in B. tabaci

    OpenAIRE

    Pan, Huipeng; Su, Qi; Jiao, Xiaoguo; Zhou, Long; Liu, Baiming; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Xu, Baoyun; Zhang, Youjun

    2013-01-01

    The impact of symbionts on their insect hosts depends on their infection density. In the current study, we investigated the effects of host plants (cucumber, cabbage, and cotton) on the relative amount of symbionts Portiera and Hamiltonella in the whitefly Bemisia tabaci (Gennadius) Q. The relative amounts of symbionts in 3 host plant B. tabaci Q populations with the same genetic background were evaluated by quantitative PCR. The whiteflies of cabbage population harbored more Portiera than th...

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    International Nuclear Information System (INIS)

    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)

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

    OpenAIRE

    Blenzar A.; Boughdad A.; Bouchelta A.

    2005-01-01

    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 u...

  12. Antixenosis evaluation in bean germoplasm (Phaseolus vulgaris L.) against Bemisia tabaci Gennadius

    OpenAIRE

    Melchiorre, G.; G. Truol; Di Feo, L. del V.

    2008-01-01

    One of the main limitations to bean yields is the whitefly Bemisia tabaci. It is an important worldwide pest that causes direct and indirect damages leading to yield decrease in crops. The objective was to evaluate antixenosis by the analysis of attraction and oviposition preference of Bemisia tabaci, biotype A, in seven bean cultivars, using free choice tests. The following parameters were measured: number of adults on the abaxial leaf surface; number of eggs/ leaf; numb...

  13. 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.

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

    OpenAIRE

    Lima L.H.C.; Návia D.; Inglis P.W.; Oliveira M.R.V. de

    2000-01-01

    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 f...

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

    International Nuclear Information System (INIS)

    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)

  16. 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

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex comprising at least 35 morphologically indistinguishable species that exhibit high genetic variation. B. tabaci is the vector of cassava mosaic geminiviruses (CMGs) causing cassava mosaic disease (CMD) to cassava...... 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...... (Portiera aleyrodidarum) essential for their survival, and many also harbour non-essential secondary symbionts. In an attempt to understand the cause of the super-abundant populations, it was suggested that a distinct genotype cluster is associated with the pandemic, however, there was no definitive proof...

  17. 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. PMID:26431703

  18. Fluctuations in peroxidase and catalase activities of resistant and susceptible black gram (Vigna mungo (L.) Hepper) genotypes elicited by Bemisia tabaci (Gennadius) feeding

    OpenAIRE

    Taggar, Gaurav Kumar; Gill, Ranjit Singh; Gupta, Anil Kumar; Sandhu, Jeet Singh

    2012-01-01

    Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleryrodidae), is a serious pest of black gram, (Vigna mungo (L.) Hepper), an important legume pulse crop grown in north India. This research investigated the potential role of selected plant oxidative enzymes in resistance/susceptibility to whitefly in nine black gram genotypes. Oxidative enzyme activity was estimated spectrophotometrically from leaf samples collected at 30 and 50 d after sowing (DAS) from whitefly infested and uninfested plan...

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

    International Nuclear Information System (INIS)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Capacidad de infestación en invernadero de los biotipos B y Q de Bemisia tabaci (Gennadius) en plantas de tomate con y sin el gen Mi

    OpenAIRE

    Baraja, M.J.; Manchón, M.A.; Nombela, Gloria; Muñiz, M.; Beitia, F.

    2002-01-01

    Se han realizado experimentos de libre elección en condiciones de invernadero para obtener la relación entre el porcentaje de plantas de tomate infestadas (y) y el número de adultos de los biotipos By Qde Bemisia tabaci Gennadius(x) mediante la función linealz=-ax,siendo z= ln[1-(y/100)], utilizándose variedades de estecultivo con y sin elgen Mi de resistencia a nematodos del género Meloidogyne y al áfido de la patata, Macrosiphum euphorbiae (Thomas). Tanto el número medio de adultos como el ...

  2. Modificación del método de las placas adhesivas amarillas para bioensayos de insecticidas en Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae)

    OpenAIRE

    Bielza Lino, Pablo; Conesa Gallego, Encarnación; Lacasa Plasencia, Alfredo; Contreras Gallego, Joséfa

    2000-01-01

    [ESP] Se ha desarrollado un método para realizar bioensayos de resistencia a insecticidas en adultos de Bemisia tabaci (Gennadius), tanto en laboratorio y como en campo. El método es una variación de un sistema ya establecido, simplificando el equipo necesario para su elaboración. Se han realizado bioensayos con este método en una población de laboratorio y en poblaciones de campo, resultando en una relación significativa entre la concentración del insecticida (endosulfán y metomilo)...

  3. 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).

    Science.gov (United States)

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

    2016-01-01

    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. tabaci present in

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

    Institute of Scientific and Technical Information of China (English)

    Lvei

    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 theophrasti Medicus), sunlfower (Helianthus annuus L.), sweet potato (Ipomoea batatas L.), soybean (Glycine max L.), and maize (Zea mays L.). The whitelfy species identity was repeatedly tested and conifrmed;seasonal dynamics on the various host plants were standardized by the quartile method. B. tabaci MED 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 2 to 3 weeks on cotton, starting in early (2010) or mid-August (2011). The common ragweed growing adjacent to cotton supported the highest B. tabaci densities (no. on 100 cm2 leaf surface), 12-22 fold higher than on cotton itself. Sunlfower supported more B. tabaci than the other plants, and about 1.5-2 fold higher than cotton did. Our results indicate that weeds (esp. the common ragweed) around cotton ifelds could increase the population density of B. tabaci MED on cotton, while sunlfower could act as a trap crop for decreasing pest pressure on cotton.

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

    OpenAIRE

    Wenxiao Du; Xiaoqing Han; Yubo Wang; Yuchuan Qin

    2016-01-01

    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% DLC...

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

    International Nuclear Information System (INIS)

    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)

  7. Invasive mechanism and manasement stratesy of Bemisia tabaci (Gennadius) biotype B: Progress report of 973 Program on invasive alien species in China

    Institute of Scientific and Technical Information of China (English)

    WAN FangHao; CUI XuHong; ZHANG LiPing; ZHANG Fan; ZHANG QingWen; LIU WanXue; LIANG Pei; LEI ZhongRen; ZHANG YongJun; ZHANG GuiFen; LIU ShuSheng; LUO Chen; CHU Dong; ZHANG YouJun; ZANG LianSheng; JIU Min; Lǖ ZhiChuang

    2009-01-01

    Bemisia tabaci (Gennadius) biotype B, called a "superbug", is one of the most harmful biotypes of this species complex worldwide. In this report, the invasive mechanism and management of B. tabaci bio-type B, based on our 5-year studies, are presented. Six B. tabaci biotypes, B, Q, ZHJ1, ZHJ2, ZHJ3 and FJ1, have been identified in China. Biotype B dominates the other biotypes in many regions of the country. Genetic diversity in biotype B might be induced by host plant, geographical conditions, and/or insecticidal application. The activities of CarE (carboxylesterase) and GSTs (glutathione-S-transferase) in biotype B reared on cucumber and squash were greater than on other host plants, which might have increased its resistance to insecticides. The higher activities of detoxification enzymes in biotype B might be induced by the secondary metabolites in host plants. Higher adaptive ability of biotype B adults to adverse conditions might be linked to the expression of heat shock protein genes. The in-digenous B. tabaci biotypes were displaced by the biotype B within 225 d. The asymmetric mating in-teractions and mutualism between biotype B and begomoviruses via its host plants speed up wide-spread invasion and displacement of other biotypes. B. tabaci biotype B displaced Trialeurodes vapo-rariorum (Westwood) after 4-7 generations under glasshouse conditions. Greater adaptive ability of the biotype B to adverse conditions and its rapid population increase might be the reasons of its suc-cessful displacement of T. vaporariorum. Greater ability of the biotype B to switch to different host plants may enrich its host plants, which might enable it to better compete with T. vaporariorum. Native predatory natural enemies possess greater ability to suppress B. tabaci under field conditions. The kairomones in the 3rd and 4th instars of biotype B may provide an important stimulus in host searching and location by its parasitoids. The present results provide useful information in

  8. Invasive mechanism and management strategy of Bemisia tabaci (Gennadius) biotype B: progress report of 973 Program on invasive alien species in China.

    Science.gov (United States)

    Wan, FangHao; Zhang, GuiFen; Liu, ShuSheng; Luo, Chen; Chu, Dong; Zhang, YouJun; Zang, LianSheng; Jiu, Min; Lü, ZhiChuang; Cui, XuHong; Zhang, LiPing; Zhang, Fan; Zhang, QingWen; Liu, WanXue; Liang, Pei; Lei, ZhongRen; Zhang, YongJun

    2009-01-01

    Bemisia tabaci (Gennadius) biotype B, called a "superbug", is one of the most harmful biotypes of this species complex worldwide. In this report, the invasive mechanism and management of B. tabaci biotype B, based on our 5-year studies, are presented. Six B. tabaci biotypes, B, Q, ZHJ1, ZHJ2, ZHJ3 and FJ1, have been identified in China. Biotype B dominates the other biotypes in many regions of the country. Genetic diversity in biotype B might be induced by host plant, geographical conditions, and/or insecticidal application. The activities of CarE (carboxylesterase) and GSTs (glutathione-S-transferase) in biotype B reared on cucumber and squash were greater than on other host plants, which might have increased its resistance to insecticides. The higher activities of detoxification enzymes in biotype B might be induced by the secondary metabolites in host plants. Higher adaptive ability of biotype B adults to adverse conditions might be linked to the expression of heat shock protein genes. The indigenous B. tabaci biotypes were displaced by the biotype B within 225 d. The asymmetric mating interactions and mutualism between biotype B and begomoviruses via its host plants speed up widespread invasion and displacement of other biotypes. B. tabaci biotype B displaced Trialeurodes vaporariorum (Westwood) after 4-7 generations under glasshouse conditions. Greater adaptive ability of the biotype B to adverse conditions and its rapid population increase might be the reasons of its successful displacement of T. vaporariorum. Greater ability of the biotype B to switch to different host plants may enrich its host plants, which might enable it to better compete with T. vaporariorum. Native predatory natural enemies possess greater ability to suppress B. tabaci under field conditions. The kairomones in the 3rd and 4th instars of biotype B may provide an important stimulus in host searching and location by its parasitoids. The present results provide useful information in

  9. Invasive mechanism and management strategy of Bemisia tabaci(Gennadius) biotype B:Progress report of 973 Program on invasive alien species in China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Bemisia tabaci(Gennadius) biotype B,called a "superbug",is one of the most harmful biotypes of this species complex worldwide.In this report,the invasive mechanism and management of B.tabaci biotype B,based on our 5-year studies,are presented.Six B.tabaci biotypes,B,Q,ZHJ1,ZHJ2,ZHJ3 and FJ1,have been identified in China.Biotype B dominates the other biotypes in many regions of the country.Genetic diversity in biotype B might be induced by host plant,geographical conditions,and/or insecticidal application.The activities of CarE(carboxylesterase) and GSTs(glutathione-S-transferase) in biotype B reared on cucumber and squash were greater than on other host plants,which might have increased its resistance to insecticides.The higher activities of detoxification enzymes in biotype B might be induced by the secondary metabolites in host plants.Higher adaptive ability of biotype B adults to adverse conditions might be linked to the expression of heat shock protein genes.The indigenous B.tabaci biotypes were displaced by the biotype B within 225 d.The asymmetric mating interactions and mutualism between biotype B and begomoviruses via its host plants speed up widespread invasion and displacement of other biotypes.B.tabaci biotype B displaced Trialeurodes vaporariorum(Westwood) after 4-7 generations under glasshouse conditions.Greater adaptive ability of the biotype B to adverse conditions and its rapid population increase might be the reasons of its successful displacement of T.vaporariorum.Greater ability of the biotype B to switch to different host plants may enrich its host plants,which might enable it to better compete with T.vaporariorum.Native predatory natural enemies possess greater ability to suppress B.tabaci under field conditions.The kairomones in the 3rd and 4th instars of biotype B may provide an important stimulus in host searching and location by its parasitoids.The present results provide useful information in explaining the mechanisms of genetic diversity

  10. Lethal and Inhibitory Activities of Plant-Derived Essential Oils Against Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) Biotype B in Tomato.

    Science.gov (United States)

    Fanela, T L M; Baldin, E L L; Pannuti, L E R; Cruz, P L; Crotti, A E M; Takeara, R; Kato, M J

    2016-04-01

    The silverleaf whitefly Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) is one of the most severe tomato pests in the world. The damage caused by this insect may compromise up to 100% of crop production, and management of this pest has relied on spraying of synthetic insecticides. However, due to the environmental issues associated with this practice, alternative methods such as the use of botanical pesticides are now used as a strategy of integrated pest management (IPM). We evaluated the effects of essential oils of five plant species on B. tabaci biotype B in tomato and demonstrate that the essential oils (0.5%) of Piper callosum (PC-EO), Adenocalymma alliaceum (AA-EO), Pelargonium graveolens (PG-EO), and Plectranthus neochilus (PN-EO) inhibit the settlement and oviposition of B. tabaci biotype B adults in tomato plants. In fumigation tests, A. alliaceum (AA-EO) at 0.4 μL/L of air after 72 h and 0.1 μL/L of air after 6 h was the most effective against nymphs and adults of B. tabaci biotype B, respectively. The major chemical constituents of PC-EO were identified as being safrole (29.3%), α-pinene (19.2%), and β-pinene (14.3%), whereas diallyl trisulfide (66.9%) and diallyl disulfide (23.3%) were the major compounds identified in AA-EO. This is the first report on the reduction of oviposition by the use of P. callosum (PC-EO) and A. alliaceum (AA-EO). In addition, the fumigant effect of A. alliaceum (AA-EO) on nymphs and adults has also been reported here for the first time. PMID:26712319

  11. TYLCSV DNA, but not infectivity, can be transovarially inherited by the progeny of the whitefly vector Bemisia tabaci (Gennadius)

    International Nuclear Information System (INIS)

    The transovarial transmission of two species of begomovirus, Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl Sardinia virus (TYLCSV), through generations of Bemisia tabaci of the B and Q biotypes has been investigated. Different life stages of the progeny of viruliferous female whiteflies have been analysed by PCR detection of viral DNA and infectivity tests. Our results indicate that TYLCSV DNA can be detected in eggs and nymphs, and to a lesser extent adults, of the first-generation progeny. Infectivity tests using a large number of adult progeny of the first, second, and third generation indicate that even when viral DNA is inherited, infectivity is not. For TYLCV, neither viral DNA nor infectivity were associated with the progeny of viruliferous female whiteflies. Because the inherited viral DNA is unable to give rise to infections, the transovarial transmission of TYLCSV DNA appears to have no epidemiological relevance

  12. 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.

  13. 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 tomato plants was significantly lower (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.

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

    Directory of Open Access Journals (Sweden)

    Tatjana Masten

    2004-06-01

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

  15. Host Plant Mediated Population Variations of Cotton Whitefly Bemisia tabaci Gennadius (Aleyrodidae: Homoptera Characterized with Random DNA Markers

    Directory of Open Access Journals (Sweden)

    Yasodha Perumal

    2009-01-01

    Full Text Available Problem statement: Whitefly, Bemisia tabaci is an important sucking pest of field, horticultural and ornamental plants causing feeding injuries besides spreading disease by acting as a vector of Gemini viruses. The polyphagous nature of the pest makes it as a highly complex species. Approach: The influence of host plants utilized by the species on the population differences at molecular level was attempted using Random Amplified Polymorphic DNA (RAPD markers. Results: Ten RAPD primers out of the total seventeen primers screened produced 236 markers. The total number of bands obtained from each primer ranged from 11-35 with an average of 23.60 bands per primer. Of the pair wise combination among thirteen species, Srivilliputhur population showed the highest similarity index (0.826 while the lowest (0.111 was recorded by Namakkal population. The similarity coefficient based on the 236 RAPD markers generated ranged from 0.111-0.826. Three major clusters were formed from UPGMA dendrogram, which was constructed based on Jaccard’s similarity. PCR screening demarcated the whitefly population based on the host species. The first cluster included population collected from okra and cotton, while second cluster comprised of population from eggplant and cauliflower and the third cluster included population from eggplant. It could be deduced that population from cotton and okra had 50% similarity, while 60-70% similarity was observed for population from eggplant and cauliflower. Conclusion: Our investigation offered the lead that within a narrow geographical region there exits variation based on host plants being utilized by the whitefly population.

  16. Implicaciones de Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) en la mejora del control biológico de Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) en el cultivo de pimiento en invernadero

    OpenAIRE

    Calvo Robles, Francisco Javier

    2011-01-01

    [ESP] La mosca blanca Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) es una plaga clave en pimiento para cuyo control se han empleado tradicionalmente agentes de control químico, dejando otras técnicas como el control biológico en un segundo plano. Sin embargo, la disminución en los últimos años del número de agentes de control químico que pueden ser empleados frente a esta y otras plagas ha despertado el interés por otras medidas de control, en especial por el control biológico. Para el c...

  17. Effect of bean genotypes, insecticides, and natural products on the control of Bemisia tabaci (Gennadius biotype B (Hemiptera: Aleyrodidae and Caliothrips phaseoli (Hood (Thysanoptera: Thripidae = Efeito de genótipos de feijoeiro, inseticida e produtos naturais no controle Bemisia tabaci (Gennadius biotipo B (Hemiptera: Aleyrodidae e Caliothrips phaseoli (Hood (Thysanoptera: Thripidae

    Directory of Open Access Journals (Sweden)

    Júlio Cesar Janini

    2011-07-01

    Full Text Available Effect of bean genotypes, insecticides, and natural products on the control of Bemisia tabaci (Gennadius biotype B (Hemiptera: Aleyrodidae and Caliothrips phaseoli (Hood (Thysanoptera: Thripidae. The influence of bean genotypes associated with neem oil as insecticide was evaluated to control B. tabaci (Gennadius biotype B and C. phaseoli (Hood during the wet season sowing. The experimental design used was the randomized block arrangement in a 4x4x3 factorial scheme, represented by genotypes, neem oil and insecticides respectively, with three replications. The genotypes Carioca, IAC Harmonia, IAC Centauro and Pérola were used. The evaluations were done at 14 and 42 days after seedling emergence, bycounting B. tabaci biotype B eggs and nymphs and C. phaseoli nymphs in the genotypes leaf. Conclusion: The B. tabaci biotype B eggs and nymphs number were smaller in IAC Centauro and higher in IAC Harmonia. The tested genotypes were similarly infested by C. phaseoli. IAC Centauro and IAC Harmonia genotypes associated with neem oil (highlighting the full dose – 1% provided lower number of whitefly eggs and thrips nymphs. Neem oil at the full dose alsoreduced whitefly nymph number. In the tested genotypes the insecticide provided reduction in the number of whitefly eggs and nymphs as well in the thrips nymphs, with increase in therecommend dose. Avaliou-se a influência de genótipos de feijoeiro associado à aplicação de óleo de nim e inseticida no controle de B. tabaci (Gennadius biótipo B e C. phaseoli (Hood na época de semeadura “das águas”. O delineamento experimental utilizados foi o de blocos casualizados dispostos em um esquema fatorial 4 x 3 x 3, representado por variedades, óleo de nim e inseticidas, respectivamente, com três repetições. Utilizaram-se os genótipos Carioca, IAC Harmonia, IAC Centauro e Pérola. As avaliações foram realizadas dos 14 aos 42 dias após a emergência das plantas, contando-se o número de ovos e

  18. The Importance of Maintaining Protected Zone Status against Bemisia tabaci

    OpenAIRE

    Cuthbertson, Andrew G. S.; Irene Vänninen

    2015-01-01

    The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of economically important crops worldwide. Both the United Kingdom (UK) and Finland hold Protected Zone status against this invasive pest. As a result B. tabaci entering these countries on plants and plant produce is subjected to a policy of eradication. The impact of B. tabaci entering, and becoming established, is that it is an effective vector of many plant viruses that are not currently found in ...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    theophrasti Medicus), sunflower (Helianthus annuus L.), sweet potato (Ipomoea batatas L.), soybean (Glycine max L.), and maize (Zea mays L.). The whitefly species identity was repeatedly tested and confirmed; seasonal dynamics on the various host plants was standardized by the quartile method. B. tabaci MED...

  1. Bemisia tabaci (Homoptera: Aleyrodidae) and Indian cassava mosaic virus transmission

    Science.gov (United States)

    Bemisia tabaci (Gennadius) adults from colonies reared on cassava or sweet potato plants were studied to determine their ability to transmit Indian cassava mosaic virus (ICMV) (Geminiviridae: Begomovirus) from cassava to cassava. Virus acquisition access (feeding) periods (AAP) of 48 h on ICMV-infec...

  2. The Importance of Maintaining Protected Zone Status against Bemisia tabaci.

    Science.gov (United States)

    Cuthbertson, Andrew G S; Vänninen, Irene

    2015-01-01

    The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of economically important crops worldwide. Both the United Kingdom (UK) and Finland hold Protected Zone status against this invasive pest. As a result B. tabaci entering these countries on plants and plant produce is subjected to a policy of eradication. The impact of B. tabaci entering, and becoming established, is that it is an effective vector of many plant viruses that are not currently found in the protected zones. The Mediterranean species is the most commonly intercepted species of B. tabaci entering both the UK and Finland. The implications of maintaining Protected Zone status are discussed. PMID:26463194

  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. 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

  5. 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

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

    OpenAIRE

    Simone Silva Vieira; Mari Inês Carissimi Boff; Adeney Freitas Bueno; Alysson Luis Gobbi; Rafael Vicentini Lobo; Regiane Cristina Oliveira de Freitas Bueno

    2012-01-01

    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. Bup...

  7. Atividade ovicida de extratos aquosos de meliáceas sobre a mosca branca Bemisia tabaci (Gennadius biótipo B em tomateiro Ovicidal activity of aqueous extracts of meliaceae on the silverleaf whitefly for tomato

    Directory of Open Access Journals (Sweden)

    Antonio Pancrácio de Souza

    2000-09-01

    Full Text Available A mosca branca Bemisia tabaci (Gennadius biótipo B atualmente é uma das principais pragas do tomateiro. O uso de extratos botânicos no controle desse inseto é uma alternativa promissora, mas que ainda precisa ser melhor pesquisada. O presente trabalho teve como objetivo determinar a bioatividade de extratos aquosos de folhas de Melia azedarach L. e de ramos de Trichilia pallida Swartz, sobre a mosca branca Bemisia tabaci (Gennadius biótipo B, criada em tomateiro. Foram realizados dois experimentos, avaliando-se a mortalidade e duração das fases de ovo e ninfa, após o tratamento da fase de ovo com os referidos extratos. No primeiro experimento, foram testadas as concentrações de 1 e 2% (p/v, acrescentando-se a concentração de 3% no segundo experimento. Em todos os tratamentos houve efeito ovicida, sendo o maior valor obtido com T. pallida a 3% (52,32%. Nos demais tratamentos, a mortalidade variou entre 16 e 37%. Os extratos aplicados sobre os ovos pouco afetaram a sobrevivência ninfal. Com exceção do tratamento com T. pallida a 2%, no primeiro experimento, em que a mortalidade ninfal foi de 26,42%, nos demais a mortalidade foi inferior a 16%. Em nenhum dos experimentos foi verificada alteração na duração dos períodos de incubação e ninfal.The silverleaf whitefly is today one of most important pests of tomato. The use of botanical extracts to control this insect is an interesting technique, but more research about it should be carried out. The objective of this work was to determine the bioactivity of aqueous extracts of Melia azedarach leaves and Trichilia pallida twigs on the silverleaf whitefly Bemisia tabaci (Gennadius biotype B, reared on tomato. Extracts were applied to eggs, and mortality and duration of egg and nymphal stages were evaluated in two experiments. In the first experiment, extracts were tested at concentrations of 1 and 2% (w/v and in the second experiment the concentration of 3% was added. The ovicidal

  8. 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...

  9. Biochemical study of resistance to imidacloprid in B-biotype Bemisia tabaci from Guatemala

    Science.gov (United States)

    Systemic uptake bioassays using excised cotton leaves confirmed resistance to imidacloprid in a Guatemalan population of the tobacco whitefly Bemisia tabaci Gennadius. Polyacrylamide gel electrophoresis of naphthyl esterases identified the insects as B-types. Upon collection from the field, resistan...

  10. Extraordinary resistance to insecticides reveals exotic Q biotype of Bemisia tabaci

    Science.gov (United States)

    The whitefly Bemisia tabaci (Gennadius) possessing unusually high levels of resistance to a wide range of insecticides were discovered in 2004 in the course of routine resistance monitoring in Arizona. The multiply-resistant insects, collected from poinsettia (Euphorbia pulcherrima) plants purchased...

  11. Climate change and Bemisia tabaci (Hemiptera: Aleyrodidae): Impacts of temperature and carbon dioxide on life history

    Science.gov (United States)

    Climate change is relevant to life around the globe. A rise in ambient temperature and CO2 may have various impacts on arthropods such as altered life cycles, modified reproductive patterns, and changes in distribution. The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a global agricultural...

  12. Determination of Genetic Variation in Populations of Bemisia tabaci in Antalya

    OpenAIRE

    GÖÇMEN, Hüseyin

    2002-01-01

    Although a number of investigations on the molecular genetics of Bemisia tabaci (Gennadius) have appeared in the literature, no such studies are known from Turkey. In order to fill this gap the amplified fragment length polymorphism (AFLP) technique was used to assay eight populations of B. tabaci collected from cotton, protected vegetables (tomato, cucumber and eggplant) and peppermint in various locations in the province of Antalya, Turkey. Eleven AFLP primer pairs detected a total of 547 ...

  13. Feeding preference of Macrolophus caliginosus (Heteroptera : Miridae) on Bemisia tabaci and Trialeurodes vaporariorum (Homoptera : Aleyrodidae)

    OpenAIRE

    Olivier Bonato; Louise Couton; Jacques Fargues

    2006-01-01

    A study of predation choices of Macrolophus caliginosus Wagner (Heteroptera: Miridae) late instars and adults, when offered various developmental stages (eggs and nymphs) of the recently established whitefly Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), was made based on two preference indices. In addition, prey choices of late instars when presented with three ratios of Trialeurodes vaporariorum (Westwood) (Homoptera: Aleyrodidae) and B. tabaci at a similar developmental stage (eggs, ...

  14. The Feeding Rate of Predatory Mites on Life Stages of Bemisia tabaci Mediterranean Species

    OpenAIRE

    Cuthbertson, Andrew G. S.

    2014-01-01

    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. There has recently been a shift from Middle East-Asia Minor 1 to the more chemical resistant Mediterranean species entering the UK. Predatory mites (Amblyseius swirskii, Transeius montdorensis and Typhlodromalus limoni...

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

    OpenAIRE

    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, ...

  16. Comparison of three trap types for adult catching of whitefly Bemisia tabaci and its parasitoid Eretmocerus mundus in tomato greenhouse

    OpenAIRE

    Nombela, G.; Chu, CC.; Heneberry, T.; Muñiz, M.

    2003-01-01

    The attractiveness of three trap types to Bemisia tabaci (Gennadius) B-biotype (= Bemisia argentifolii Bellows & Perring) and Eretmocerus mundus Mercet adult was compared in two choice experiments in a greenhouse at the Centro de Ciencias Medioambientales, Madrid, Spain.  Yellow sticky cards equipped with light-emitting-diodes (LED-YC) caught more adults per trap per day than yellow sticky card (YC) traps.YC traps caught significantly more B. tabaci and E. mundus adults than plastic cup traps...

  17. Tri-Tek (Petroleum Horticultural Oil) and Beauveria bassiana: Use in Eradication Strategies for Bemisia tabaci Mediterranean Species in UK Glasshouses

    OpenAIRE

    Cuthbertson, Andrew G. S.; Collins, Debbie A.

    2015-01-01

    The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest of global importance on both outdoor and glasshouse crops. To date, B. tabaci has not become established in the UK. 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. Mediterranean species is now the most prevalent Bemisia species entering the UK. Increasing neonicotinoid resistance is becoming increasingly wid...

  18. 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

  19. The Field Trial of Several Insecticides against Bemisia tabaci(Gennadius)on Cabbage(Brassica oleracea)%几种杀虫剂防治甘蓝烟粉虱田间药效试验研究

    Institute of Scientific and Technical Information of China (English)

    李兴东; 王小丽; 王潍波

    2014-01-01

    以期为烟粉虱的防治提供参考,比较了几种不同类型杀虫剂对甘蓝烟粉虱的田间防治效果,结果表明:10%烯啶虫胺、25%阿克泰、10%吡虫啉、1.8%害极灭和25%吡蚜酮对烟粉虱均具有较好的防治效果,9 d后的防效分别达到89.57%、96.11%、76.56%、90.52%、88.68%。25%扑虱灵、4.5%高效氯氰菊酯、2.5%高效氯氟氢菊酯和40%毒死蜱对烟粉虱的防效较差,已失去对烟粉虱的有效防治。%The toxicity of several insecticides on Bemisia tabaci is determined in this test,so as to provide the reference for prevention and control of Bemisia tabaci.The results show that 10% nitenpyram AS,25% thiamethoxam WG,10% imidacloprid WP,1.8% abamectin EC and 25% pymertrozine WP have good control effect on Bemisia tabaci. The control effects are 89.57%,96.11%,75.56%,90.52%,88.68% respectively after 9-day treatment.The control effects of 25% buprofezin WP,4.5% Beta-cypermethrin EC,2.5%cyhalothrin WP,and 40%chlorpyrifos EC are bad.They cannot be used for prevention and control against Bemisia tabaci.

  20. Comparison of three single-nozzle operator-carried spray applicators for whitefly (Bemisia tabaci) management on squash

    Science.gov (United States)

    Whiteflies cause problems in vegetable production on a global scale. The primary worldwide whitefly pest is Bemisia tabaci (Gennadius). Insecticides are commonly used to mitigate the whitefly problem in vegetable crops. In limited-resource crop production, operator-carried spray applicators are comm...

  1. Introduction and Recovery of Delphastus catalinae (Coleoptera: Coccinellidae) as a predator of Bemisia tabaci (Hemiptera: Aleyrodidae) in Egypt

    Science.gov (United States)

    Bemisia tabaci (Gennadius) (Hemiptera: Alyerodidae) is an important pest of many crops on a global scale. The use of biological control organisms such as coccinelid predators can help manage this pest. Delphastus catalinae (Horn) (Coleoptera: Coccinelidae) is an obligate predator of whiteflies, in...

  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. PMID:26314072

  3. Bioactivity of Indigenous Medicinal Plants against the Cotton Whitefly, Bemisia tabaci

    OpenAIRE

    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...

  4. Isolation and characterization of nine microsatellite loci from bemisia tabaci (Hemiptera: Aleyrodidae) Biotype B

    OpenAIRE

    Hadjistylli, M.; Schwartz, SA; Brown, JK; Roderick, GK

    2014-01-01

    © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America. Nine microsatellites were isolated from Bemisia tabaci (Gennadius) biotype B and screened across 60 individuals from two populations (biotype B) to examine polymorphism. Two to 12 alleles were observed per locus. Observed and expected heterozygosities ranged from 0.033 to 0.967 and 0.033 to 0.854, respectively. There was no significant deviation from Hardy-Weinberg equilibrium and no sig...

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

    OpenAIRE

    Hagler, James R.; Jackson, Charles G.; Rufus Isaacs; Machtley, Scott A.

    2004-01-01

    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 prey...

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

    OpenAIRE

    Luis Latournerie-Moreno; Alex Ic-Caamal; Esaú Ruiz-Sánchez; Horacio Ballina-Gómez; Ignacio Islas-Flores; Wilberth Chan-Cupul; Daniel González-Mendoza

    2015-01-01

    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-rela...

  7. Research on tomato resistance to the virus-transmitter whitefly Bemisia tabaci undertaken during the last years in Madrid (Spain)

    OpenAIRE

    Muñiz, M.; Nombela, G.

    2009-01-01

    Whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important pest of horticultural crops worldwide, including tomato plants, whose damage may be directly through phloem feeding or indirectly by the transmission of plant viruses such as Tomato Yellow Leaf Curl Viruses. Although control of B. tabaci is based mainly on the application of insecticides, most of these chemicals are environmentally toxic and whiteflies appear to be resistant to many of them. Among the most outstandin...

  8. Trade-Offs between Survival, Longevity, and Reproduction, and Variation of Survival Tolerance in Mediterranean Bemisia tabaci after Temperature Stress

    OpenAIRE

    Lü, Zhi-Chuang; Wang, Yan-Min; Zhu, Shao-Guang; Yu, Hao; Guo, Jian-Ying; Wan, Fang-Hao

    2014-01-01

    The invasive Mediterranean Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) has emerged as one of the most common agricultural pests in the world. In the present study, we examined the cross-tolerance, fitness costs, and benefits of thermal tolerance and the variation in the responses of life history traits after heat-shock selection. The results showed that survival and longevity of Mediterranean B. tabaci were decreased significantly after direct or cross temperature stress and that the ...

  9. The virus-transmitter whitefly Bemisia tabaci increases tomato susceptibility to subsequent infestation by the same insect pest

    OpenAIRE

    Nombela, Gloria; Pascual, S.; Gómez, Azahara A.; Avilés, M; Alonso, D.; Muñiz, M.

    2007-01-01

    Efficient management of virus diseases requires a global knowledge of all factors involved, which includes the behaviour of vector insects. Both, B- and Q-biotypes of whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) are important pests of horticultural crops worldwide due to their ability to transmit a number of plant viruses to different cultivated species, including tomato. Infestation by pests or pathogens can induce responses in the plant that affect to a subsequent infest...

  10. Quantification and Localization of Watermelon Chlorotic Stunt Virus and Tomato Yellow Leaf Curl Virus (Geminiviridae) in Populations of Bemisia tabaci (Hemiptera, Aleyrodidae) with Differential Virus Transmission Characteristics

    OpenAIRE

    Mario Kollenberg; Stephan Winter; Monika Götz

    2014-01-01

    Bemisia tabaci (Gennadius) is one of the economically most damaging insects to crops in tropical and subtropical regions. Severe damage is caused by feeding and more seriously by transmitting viruses. Those of the genus begomovirus (Geminiviridae) cause the most significant crop diseases and are transmitted by B. tabaci in a persistent circulative mode, a process which is largely unknown. To analyze the translocation and to identify critical determinants for transmission, two populations of B...

  11. Prey Preference and Life Table of Amblyseius orientalis on Bemisia tabaci and Tetranychus cinnabarinus.

    Science.gov (United States)

    Zhang, Xiaoxiao; Lv, Jiale; Hu, Yue; Wang, Boming; Chen, Xi; Xu, Xuenong; Wang, Endong

    2015-01-01

    Amblyseius orientalis (Ehara) (Acari: Phytoseiidae) is a native predatory mite species in China. It used to be considered as a specialist predator of spider mites. However, recent studies show it also preys on other small arthropod pests, such as Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Experiments were conducted to investigate (1) prey preference of A. orientalis between Tetranychus cinnabarinus (Boisd.) (Acari: Tetranychidae) and B. tabaci, and (2) development, consumption and life table parameters of A. orientalis when reared on T. cinnabarinus, B. tabaci or a mix of both prey species. When preying on different stages of T. cinnabarinus, A. orientalis preferred protonymphs, whereas when preying on different stages of B. tabaci, A. orientalis preferred eggs. When these two most preferred stages were provided together (T. cinnabarinus protonymphs and B. tabaci eggs), A. orientalis randomly selected its prey. Amblyseius orientalis was able to complete its life cycle on B. tabaci eggs, T. cinnabarinus protonymphs, or a mix of both prey. However, its developmental duration was 53.9% and 30.0% longer when reared on B. tabaci eggs than on T. cinnabarinus and a mix of both prey, respectively. In addition, it produced only a few eggs and its intrinsic rate of increase was negative when reared on B. tabaci eggs, which indicates that B. tabaci is not sufficient to maintain A. orientalis population. The intrinsic rates of increase were 0.16 and 0.23 when A. orientalis was fed on the prey mix and T. cinnabarinus, respectively. These results suggest that although B. tabaci is a poor food resource for A. orientalis in comparison to T. cinnabarinus, A. orientalis is able to sustain its population on a mix of both prey. This predatory mite may thus be a potential biological control agent of B. tabaci when this pest co-occurs with the alternative minor pest T. cinnabarinus. PMID:26436422

  12. Prey Preference and Life Table of Amblyseius orientalis on Bemisia tabaci and Tetranychus cinnabarinus.

    Directory of Open Access Journals (Sweden)

    Xiaoxiao Zhang

    Full Text Available Amblyseius orientalis (Ehara (Acari: Phytoseiidae is a native predatory mite species in China. It used to be considered as a specialist predator of spider mites. However, recent studies show it also preys on other small arthropod pests, such as Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae. Experiments were conducted to investigate (1 prey preference of A. orientalis between Tetranychus cinnabarinus (Boisd. (Acari: Tetranychidae and B. tabaci, and (2 development, consumption and life table parameters of A. orientalis when reared on T. cinnabarinus, B. tabaci or a mix of both prey species. When preying on different stages of T. cinnabarinus, A. orientalis preferred protonymphs, whereas when preying on different stages of B. tabaci, A. orientalis preferred eggs. When these two most preferred stages were provided together (T. cinnabarinus protonymphs and B. tabaci eggs, A. orientalis randomly selected its prey. Amblyseius orientalis was able to complete its life cycle on B. tabaci eggs, T. cinnabarinus protonymphs, or a mix of both prey. However, its developmental duration was 53.9% and 30.0% longer when reared on B. tabaci eggs than on T. cinnabarinus and a mix of both prey, respectively. In addition, it produced only a few eggs and its intrinsic rate of increase was negative when reared on B. tabaci eggs, which indicates that B. tabaci is not sufficient to maintain A. orientalis population. The intrinsic rates of increase were 0.16 and 0.23 when A. orientalis was fed on the prey mix and T. cinnabarinus, respectively. These results suggest that although B. tabaci is a poor food resource for A. orientalis in comparison to T. cinnabarinus, A. orientalis is able to sustain its population on a mix of both prey. This predatory mite may thus be a potential biological control agent of B. tabaci when this pest co-occurs with the alternative minor pest T. cinnabarinus.

  13. Densities of Eggs and Nymphs and Percent Parasitism of Bemisia tabaci (Hemiptera: Aleyrodidae) on Common Weeds in West Central Florida

    OpenAIRE

    Smith, Hugh A.; Nagle, Curtis A.; Gregory A. Evans

    2014-01-01

    The density of eggs and nymphs of Bemisia tabaci (Gennadius) biotype B and the percent parasitism of the nymphs were measured from specimens collected on nine species of weeds, commonly found in west central Florida during the spring and summer of 2012 and 2013. The weeds were direct seeded in 2012 and grown as transplants in 2013 for Randomized Complete Block design experiments. The leaf area of each whole-plant sample was measured and the B. tabaci density parameters were converted to numbe...

  14. Oviposition, Development and Survivorship of the sweetpotato Whitefly Bemisia tabaci on Soybean, Glycine max, and the Garden Bean, Phaseolus vulgaris

    OpenAIRE

    Mansaray, Augustine; Sundufu, Abu James

    2009-01-01

    Oviposition, development and survivorship of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) were evaluated on soybean and garden bean under laboratory conditions of 26.0 ± 0.5 °C, 70 – 80% RH and a photoperiod of 14:10 (L:D). B. tabaci deposited more eggs and survivorship of nymphs was significantly greater in a choice-test on soybean, Glycine max L. (Merr.) (Fabeles: Fabaceae), compared to the garden bean, Phaseolus vulgaris L. Overall developmental time from egg to adult eclosion was l...

  15. Insecticide resistance in Bemisia tabaci from Cyprus

    Institute of Scientific and Technical Information of China (English)

    Vassilis Vassiliou; Maria Emmanouilidou; Andreas Perrakis; Evangelia Morou; John Vontas; Anastasia Tsagkarakou; Emmanouil Roditakis

    2011-01-01

    A comprehensive study on the Bemisia tabaci(biotype B)resistance to neonicotinoid insecticides imidacloprid,acetamiprid and thiamethoxam,and pyrethroid bifenthrin was conducted in Cyprus.The resistance level to eight field-collected B.tabaci populations was investigated.The activities of enzymes involved in metabolic detoxification and the frequencies of pyrethroid and organophosphates target site resistance mutations were determined.Moderate to high levels of resistance were detected for imidacloprid(resistance factor[RF]77-392)and thiamethoxam(RF 50-164)while low resistance levels were observed for acetamiprid(RF 7-12).Uniform responses by the Cypriot whiteflies could be observed against all neonicotinoid insecticides.No cross-resistance between the neonicotinoids was detected as well as no association with the activity of the P450 microsomal oxidases.Only imidacloprid resistance correlated with carboxylesterase activity.Low to extremely high resistance was observed for insecticide bifenthrin(RF 49-1 243)which was associated with the frequency of the resistant allele in the sodium channel gene but not with the activity of the detoxification enzymes.Finally,the F331W mutation in the acetylcholinesterase enzyme ace1 gene was fixed in all B.tabaci populations from Cyprus.

  16. Diversity of secondary endosymbionts among different putative species of the whitefly Bemisia tabaci

    Institute of Scientific and Technical Information of China (English)

    Xiao-Li Bing; Yong-Ming Ruan; Qiong Rao; Xiao-Wei Wang; Shu-Sheng Liu

    2013-01-01

    Endosymbionts are important components of arthropod biology.The whitefly Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae) is a cryptic species complex composed of≥28 putative species.In addition to the primary endosymbiont Portiera aleyrodidarum,six secondary endosymbionts (S-endosymbionts),Hamiltonella,Rickettsia,Wolbachia,Cardinium,Arsenophonus and Fritschea,have been identified in B.tabaci thus far.Here,we tested five of the six S-endosymbiont lineages (excluding Fritschea) from 340 whitely individuals representing six putative species from China.Hamiltonella was detected only in the two exotic invaders,Middle East-Asia Minor 1 (MEAM 1) and Mediterranean (MED).Rickettsia was absent in Asia Ⅱ 1 and MED,scarce in Asia Ⅱ 3 (13%),but abundant in Asia Ⅱ 7 (63.2%),China 1 (84.7%) and MEAM1 (100%).Wolbachia,Cardinium and Arsenophonus were absent in the invasive MEAM 1 and MED but mostly abundant in the native putative species.Furthermore,phylogenetic analyses revealed that some S-endosymbionts have several clades and different B.tabaci putative species can harbor different clades of a given S-endosymbiont,demonstrating further the complexity of S-endosymbionts in B.tabaci.All together,our results demonstrate the variation and diversity of S-endosymbionts in different putative species ofB.tabaci,especially between invasive and native whiteflies.

  17. Bemisia tabaci: The current situation in the UK and the prospect of developing strategies for eradication using entomopathogens

    Institute of Scientific and Technical Information of China (English)

    Andrew G.S.Cuthbertson; Lisa F.Blackburn; Dominic P.Eyre; Raymond J.C.Cannon; Judith Miller; Phil Northing

    2011-01-01

    The sweetpotato whitefly,Bemisia tabaci(Gennadius)(Hemiptera: Aleyrodidae)remains a serious threat to crops worldwide.The damaging B-biotype is of specific economic concern because it is an effective vector of over 111 viruses from several families,particularly geminiviruses.Bemisia tabaci is regularly intercepted on plants coming into the UK where it is subjected to a policy of eradication.The UK maintains Protective Zone status against this pest.A main pathway of entry of B.tabaci into the Protected Zone involves propagating material,especially Poinsettia(Euphorbia pulcherrima).With increased insecticide resistance continuously being recorded,B.tabaci is becoming more difficult to control/eradicate.Recent research involving both entomopathogenic nematodes and fungi is showing much potential for the development of control programs for this pest.Both the nematode Steinernema feltiae and the fungus Lecanicillium muscarium have been shown to be most effective against second instar B.tabaci.Fine-tuning of the environmental conditions required has also increased their efficacy.The entomopathogens have also shown a high level of compatibility with chemical insecticides,all increasing their potential to be incorporated into control strategies against B.tabaci.

  18. Genetic structure of the whitefly Bemisia tabaci populations in Colombia following a recent invasion.

    Science.gov (United States)

    Díaz, Fernando; Endersby, Nancy M; Hoffmann, Ary A

    2015-08-01

    The whitefly Bemisia tabaci (Gennadius) is one of the most important pests causing economic losses in a variety of cropping systems around the world. This species was recently found in a coastal region of Colombia and has now spread inland. To investigate this invasive process, the genetic structure of B. tabaci was examined in 8 sampling locations from 2 infested regions (coastal, inland) using 9 microsatellite markers and the mitochondrial COI gene. The mitochondrial analysis indicated that only the invasive species of the B. tabaci complex Middle East-Asia Minor 1 (MEAM 1 known previously as biotype B) was present. The microsatellite data pointed to genetic differences among the regions and no isolation by distance within regions. The coastal region in the Caribbean appears to have been the initial point of invasion, while the inland region in the Southwest showed genetic variation among populations most likely reflecting founder events and ongoing changes associated with climatic and topographical heterogeneity. These findings have implications for tracking and managing B. tabaci. PMID:24753322

  19. 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; Wan, Fang-Hao

    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....... However, resource preoccupied by T. vaporariorum had only minor detrimental effectsonthe performanceof later-arriving B. tabaci MEAM1.In theopposite colonisation sequence, previous occupation by B. tabaci MEAM1 had no significant effects on the life history parameters of later-arriving conspecifics, but...... severe detrimental effects were observed on the performance of later-arriving T. vaporariorum. Total immature survival of T. vaporariorum decreased in both weak and strong previous occupation situations by B. tabaci MEAM1. CONCLUSION: The interspecific interactions between B. tabaci MEAM1 and T...

  20. Life History of Delphastus Catalinae: a predator of Bemisia tabaci

    Science.gov (United States)

    Immature development and reproductive life history of Delphastus catalinae (Coleoptera: Coccinellidae) feeding on Bemisia tabaci (Homoptera: Aleyrodidae) immatures was studied at three constant temperatures: 22, 26 and 30 ºC. Development rates and lower temperature threshold temperatures (T0) were e...

  1. Effects of selected fertilizers on the life history of Bemisia tabaci (Hemiptera: Aleyrodidae) biotype B.

    Science.gov (United States)

    England, K M; Sadof, C S; Cañnas, L A; Kuniyoshi, C H; Lopez, R G

    2011-04-01

    We tested the effects among a purportedly sustainable water-soluble fertilizer, a conventional water-soluble fertilizer, an alternation of these, a controlled-release fertilizer, and a clear water control on the life-history traits of sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae; =Bemisia argentifolii Bellows & Perring) biotype B reared on poinsettia (Euphorbia pulcherrima Willdenow ex Klotzch). Free amino acids in petioles were measured to estimate plant nutrient assimilation and phloem nutritional quality for B. tabaci biotype B. The sustainable fertilizer produced plants with the highest concentration of amino acids. In contrast, fecundity of whiteflies was lowest in plants treated with the sustainable fertilizer and the water control. The relationship between total amino acids in phloem and survival was significantly quadratic, with the highest survival at intermediate levels. Fecundity, however, was negatively correlated with total amino acid content of the maternal host plant. Variation in total amino acid concentration in petioles of plants treated within fertilizer treatments makes it difficult to predict whether a particular fertilizer will produce plants with enough amino acids to deleteriously affect both survivorship and fecundity and yet yield a plant of good quality. Despite this limitation, we can conclude that the use of this sustainable fertilizer will not cause increases in whitefly populations relative to plants fertilized with water-soluble and slow-release fertilizers that deliver the same level of nitrogen to the plant. PMID:21510203

  2. Study on the Occurrence Regularity of Invasive Whitefly Bemisia Tabaci Population

    Directory of Open Access Journals (Sweden)

    Xu Senfu

    2013-11-01

    Full Text Available The B biotype whitefly Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae is an invasive species in China, witch severely damage the production of numerous crops through direct feeding and transmission of plant viruses. In order to clarify the major biological characteristics of a whitefly as an alien invasive species, reveal the seasonal growth and decline of its population quantity, the law of fluctuation from year to year and it’s influencing factors and improves the monitoring, prevention and control level. Our study investigates the main biological characteristics and the population quantity’s fluctuation of the whitefly Bemisia tabaci in Linhai, Zhejiang province, China. Adult whiteflies were investigated in the greenhouse and field from 2006 to 2011 with using yellow sticky boards. The results show that the whiteflies can produce 11 generations each year with an evident generation overlapping. The number of whiteflies in the greenhouse started to increase from June, with a significant increase after July and then reached its peak during August and September. With the temperature drop, the whitefly population started to decrease after mid-October. The observation of the insects indicated that whiteflies are capable of surviving within the whole year under the greenhouse condition. On the other hand, the overwintering frequency for the whitefly in the open field was approximately 20%. Moreover, the main factors that affect the population dynamics of whiteflies in the field include the initial population number, climate condition, farming system and flood inundation, among which, the temperature condition is the most important.

  3. 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.

  4. Host selection by the autoparasitoid Encarsia pergandiella on primary (Bemisia tabaci) and secondary (Eretmocerus mundus) hosts.

    Science.gov (United States)

    Zhang, Yi-Bo; Castañé, Cristina; Gabarra, Rosa; Albajes, Ramon; Wan, Fang-Hao

    2015-12-01

    In autoparasitoids, females are generally primary endoparasitoids of Hemiptera, while males are hyperparasitoids developing in or on conspecific females or other primary parasitoids. Female-host acceptance can be influenced by extrinsic and/or intrinsic factors. In this paper, we are concerned with intrinsic factors such as nutritional status, mating status, etc. We observed the behavior of Encarsia pergandiella Howard (Hymenoptera: Aphelinidae) females when parasitizing primary (3rd instar larvae of Bemisia tabaci Gennadius [Homoptera: Aleyrodidae]) and secondary hosts (3rd instar larvae and pupae of Eretmocerus mundus Mercet [Hymenoptera: Aphelinidae]) for a period of 1 h. Females had different reproductive (virgin or mated younger) and physiological (fed elder or mated elder) status. Virgin females killed a large number of secondary hosts while investing a long time per host. However, they did not feed upon them. Mated females killed a lower number of secondary hosts and host feeding was observed in both consuming primary and secondary hosts. It was common to observe host examining females of all physiological statues tested repeatedly stinging the same hosts when parasitizing, killing or rejecting them. Fed elder females parasitized more B. tabaci larvae than E. mundus larvae or pupae, while investing less time on the primary host than on the secondary host. They also parasitized more B. tabaci larvae than mated elder females, while investing less time per host. The access of females to honey allowed them to lay more eggs. PMID:24992443

  5. 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. PMID:26488331

  6. Extraordinary resistance to insecticides reveals exotic Q biotype of Bemisia tabaci in the New World.

    Science.gov (United States)

    Dennehy, Timothy J; Degain, Benjamin A; Harpold, Virginia S; Zaborac, Marni; Morin, Shai; Fabrick, Jeffrey A; Nichols, Robert L; Brown, Judith K; Byrne, Frank J; Li, Xianchun

    2010-12-01

    A strain of the whitefly Bemisia tabaci (Gennadius) possessing unusually high levels of resistance to a wide range of insecticides was discovered in 2004 in the course of routine resistance monitoring in Arizona. The multiply resistant insects, collected from poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) plants purchased at a retail store in Tucson, were subjected to biotype analysis in three laboratories. Polyacrylamide gel electrophoresis of naphthyl esterases and sequencing of the mitochondrial cytochrome oxidase I gene (780 bp) confirmed the first detection of the Q biotype of B. tabaci in the New World. This U.S. Q biotype strain, referred to as Poinsettia'04, was highly resistant to two selective insect growth regulators, pyriproxyfen and buprofezin, and to mixtures of fenpropathrin and acephate. It was also unusually low in susceptibility to the neonicotinoid insecticides imidacloprid, acetamiprid, and thiamethoxam, relative to B biotype whiteflies. In 100 collections of whiteflies made in Arizona cotton (Gossypium spp.), vegetable, and melon (Cucumis melo L.) fields from 2001 to 2005, no Q biotypes were detected. Regions of the United States that were severely impacted by the introduction of the B biotype of B. tabaci in the 1980s would be well advised to promote measures that limit movement of the Q biotype from controlled environments into field systems and to formulate alternatives for managing this multiply-resistant biotype, in the event that it becomes more widely distributed. PMID:21309242

  7. Extensive survey of Bemisia tabaci (Hemiptera: Aleyrodidae) biotypes in Florida investigating the Q invasion

    Science.gov (United States)

    After the discovery of the Bemisia tabaci Q biotype in the U.S., there was an urgent need to determine its spread. As part of a coordinated whole country survey, an extensive survey of Bemisia tabaci biotypes was conducted in Florida through cooperation with growers and state agencies. This was done...

  8. Sequence variation of Bemisia tabaci Chemosensory Protein 2 in cryptic species B and Q: New DNA markers for whitefly recognition.

    Science.gov (United States)

    Liu, Guo-Xia; Ma, Hong-Mei; Xie, Hong-Yan; Xuan, Ning; Picimbon, Jean-François

    2016-01-15

    Bemisia tabaci Gennadius biotypes B and Q are two of the most important worldwide agricultural insect pests. Genomic sequences of Type-2 B. tabaci chemosensory protein (BtabCSP2) were cloned and sequenced in B and Q biotypes, revealing key biotype-specific variations in the intron sequence. A Q260 sequence was found specifically in Q-BtabCSP2 and Cucumis melo LN692399, suggesting ancestral horizontal transfer of gene between the insect and the plant through bacteria. A cleaved amplified polymorphic sequences (CAPS) method was then developed to differentiate B and Q based on the sequence variation in exon of BtabCSP2 gene. The performances of CSP2-based CAPS for whitefly recognition were assessed using B. tabaci field collections from Shandong Province (P.R. China). Our SacII based CAPS method led to the same result compared to mitochondrial cytochrome oxidase-based CAPS method in the field collections. We therefore propose an explanation for CSP origin and a new rapid simple molecular method based on genomic DNA and chemosensory gene to differentiate accurately the B and Q whiteflies of the Bemisia complex around the world. PMID:26481237

  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. Comparative Morphology and Morphometry of Six Biotypes of Bemisia tabaci (Hemiptera:Aleyrodidae) from China

    Institute of Scientific and Technical Information of China (English)

    LI Jing-jing; TANG Qing-bo; BAI Run-e; LI Xiao-min; JIANG Jin-wei; ZHAI Qing; YAN Feng-ming

    2013-01-01

    Morphology and morphometry of six biotypes (B, Q, Cv, ZHJ-1, ZHJ-2 and ZHJ-3) of Bemisia tabaci (Gennadius) from China on cotton plants were studied by using microscopes. Nymphal body sizes and characters were measured and observed, especially on the 4th instar (pupal case), including the vasiform orifice, operculum, lingula, length and thickness of anterior and posterior wax margins, width of thoracic tracheal combs. Adult characters of both sexes were investigated including the body size, compound eyes, antennal segments, vasiform orifice, hind tarsi and genitals. The results indicated that differences of some morphological characters or morphometrics were significant among the six biotypes of B. tabaci in China:(1) Pupal sizes of the exotic biotypes (B and Q) were significantly larger than the indigenous biotypes with the following order as B>Q>ZHJ-1>Cv>ZHJ-3>ZHJ-2;(2) for both male and female adults, sizes of all characters investigated in the invading biotypes (B and Q), especially B, were much larger than those of the indigenous ones.

  11. 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.

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

    OpenAIRE

    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 Bem...

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Bemisia tabaci: A new clip-cage for biological studies

    OpenAIRE

    Muñiz, M.; Nombela, G.

    2001-01-01

    This new clip-cage has been designed in our laboratory. It is a transparent plastic truncated cone clip-cage (3.6 cm x 2.6 cm diameter; 4 cm high). A very thin polypropylene mesh (30 holes/inch) is attached to the bottom by paraffin wax. We have used this clip-cage attached to the under surface of the leaves in our studies on the biology of both B and Q biotypes of Bemisia tabaci with excellent results.

  15. Rickettsia influences thermotolerance in the whitefly Bemisia tabaci B biotype

    Institute of Scientific and Technical Information of China (English)

    Marina Brumin; Svetlana Kontsedalov; Murad Ghanim

    2011-01-01

    The whitefly Bemisia tabaci harbors Portiera aleyrodidarum,an obligatory symbiotic bacterium,as well as several secondary symbionts,including Rickettsia,Hamiltonella,Wolbachia,Arsenophonus,Cardinium and Fritschea,the function of which is unknown.In Israel,Rickettsia is found in both the B and Q of B.tabaci biotypes,and while all other secondary symbionts are located in the bacteriomes,Rickettsia can occupy most of the body cavity of the insect.We tested whether Rickettsia influences the biology of B.tabaci and found that exposing a Rickettsia-containing population to increasing temperatures significantly increases its tolerance to heat shock that reached 40℃,compared to a Rickettsia-free population.This increase in tolerance to heat shock was not associated with specific induction of heat-shock protein gene expression; however,it was associated with eduction in Rickettsia numbers as was assessed by quantitative real-time polymerase chain reaction and fluorescence in situ hybridization analyses.To assess the causes for thermotolerance when ickettsia is reduced,we tested whether its presence is associated with the induction of genes required for thermotolerance.We found that under normal 25℃ rearing temperature,genes associated with response to stress such as cytoskeleton genes are induced in the Rickettsia-containing population.Thus,the presence of Rickettsia in B.tabaci under normal conditions induces the expression of genes required for thermotolerance that under high temperatures indirectly lead to this tolerance.

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

    Science.gov (United States)

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

  17. 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. PMID:25373231

  18. Behavioral Response of Bemisia tabaci (Hemiptera: Aleyrodidae) to 20 Plant Extracts.

    Science.gov (United States)

    Emilie, Deletre; Mallent, Maelle; Menut, Chantal; Chandre, Fabrice; Martin, Thibaud

    2015-08-01

    In the Mediterranean region, the use of small-mesh netting to protect horticultural crops is an effective sustainable tool against pests. But in tropical regions, because of high humidity under the net favoring fungal development, netting with a larger mesh size has to be used, protecting crops against lepidopteran pests but not against small pests such as hemipterans, thrips, and phytophagous mites. A combination of netting with a repellent or irritant product is one possible solution, but the desire to reduce the use of synthetic chemicals and mitigate resistance issues calls for a natural alternative. The objective of this study was to evaluate the repellent, irritant, and toxic effects of nets dipped in 20 different plant extracts on Bemisia tabaci (Gennadius) adults. The repellent effect of volatile compounds was evaluated using a still-air olfactometer. The irritant effect and toxicity were evaluated with a no-choice test in tubes separated into two parts by an impregnated net. Our results showed the seven most irritant and toxic products against B. tabaci were aframomum, cinnamon, geranium, dill, citronella, litsea, and savory. The most repellent were aframomum and lemongrass, although cinnamon, geranium, and savory were also repellent at higher doses. Effects varied with the plant extract and the concentration, and effects were independent of one another, i.e., an essential oil can be irritant but not repellent, suggesting that the repellent mechanism and that behind the irritant or toxic effects is not the same. The use of repellent compounds in combination with netting as new pest control strategy is discussed. PMID:26470332

  19. 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. PMID:27001484

  20. 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. PMID:26826802

  1. The evolutionary dynamics of insecticide resistance in the whitefly, Bemisia tabaci

    OpenAIRE

    Jones, Christopher Mark

    2011-01-01

    The whitefly Bemisia tabaci (Hempitera: Aleyrodidae), is one of most destructive insect pests of agriculture and horticulture worldwide. B. tabaci has an extensive host-plant range, transmits several plant viruses and is a highly invasive species. Managing B. tabaci is therefore extremely problematic and expensive, with a heavy burden placed upon insecticides. Despite a broad spectrum of insecticidal chemistry available for whitefly control, resistance is widespread and insecticide resistance...

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

    OpenAIRE

    L.H.C. Lima; Campos, L; M.C. Moretzsohn; D. Návia; M.R.V. de Oliveira

    2002-01-01

    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 ...

  3. Characterization of a Newly Discovered Symbiont of the Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae)

    OpenAIRE

    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 Chi...

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

    OpenAIRE

    Fatemeh Yarahmadi; Ali Rajabpour; Nooshin Zandi Sohani; Leila Ramezani

    2013-01-01

    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 concen...

  5. Acylsucrose-Producing Tomato Plants Forces Bemisia tabaci to Shift Its Preferred Settling and Feeding Site

    OpenAIRE

    Rodríguez-López, M. J.; Garzo, E.; Bonani, J. P.; Fernández-Muñoz, R.; Moriones, E.; Fereres, Alberto

    2012-01-01

    Background The whitefly Bemisia tabaci (Genn.) causes dramatic damage to plants by transmitting yield-limiting virus diseases. Previous studies proved that the tomato breeding line ABL 14-8 was resistant to B. tabaci, the vector of tomato yellow leaf curl disease (TYLCD). This resistance is based on the presence of type IV glandular trichomes and acylsucrose production. These trichomes deter settling and probing of B. tabaci in ABL 14-8, which reduces primary and secondary spread of TYLCD. Me...

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  8. Glucosinolate Desulfation by the Phloem-Feeding Insect Bemisia tabaci.

    Science.gov (United States)

    Malka, Osnat; Shekhov, Anton; Reichelt, Michael; Gershenzon, Jonathan; Vassão, Daniel Giddings; Morin, Shai

    2016-03-01

    Glucosinolates are plant secondary defense metabolites confined nearly exclusively to the order Brassicales. Upon tissue rupture, glucosinolates are hydrolyzed to various bioactive breakdown products by the endogenous plant enzyme myrosinase. As the feeding of chewing insect herbivores is associated with plant tissue damage, these insects have developed several independent strategies for coping with the glucosinolate-myrosinase defense system. On the other hand, our knowledge of how phloem-feeding insects interact with the glucosinolate-myrosinase system is much more limited. In fact, phloem feeders might avoid contact with myrosinase altogether so their susceptibility to intoxication by glucosinolate hydrolysis products is unclear. Previous studies utilizing Arabidopsis thaliana plants accumulating high levels of aliphatic- or indolic-glucosinolates indicated that both glucosinolate groups have moderate negative effects on the reproductive performance of Bemisia tabaci, a generalist phloem-feeding insect. To get a deeper understanding of the interaction between B. tabaci and glucosinolate-defended plants, adults were allowed to feed on artificial diet containing intact glucosinolates or on Brussels sprout and A. thaliana plants, and their honeydew was analyzed for the presence of possible metabolites. We found that B. tabaci is capable of cleaving off the sulfate group of intact glucosinolates, producing desulfoglucosinolates that cannot be activated by myrosinases, a mechanism described to date only in several chewing insect herbivores. The presence of desulfated glucosinolates in the honeydew of a generalist phloem-feeder may indicate the necessity to detoxify glucosinolates, likely due to some level of cellular damage during feeding, which results in glucosinolate activation, or as a mechanism to circumvent the non-enzymatic breakdown of indolic glucosinolates. PMID:26961756

  9. Factors affecting the attack rate of Bemisia tabaci on cucumber Fatores que afetam o ataque de Bemisia tabaci em pepino

    Directory of Open Access Journals (Sweden)

    Germano Leão Demolin Leite

    2006-08-01

    Full Text Available The objective of this work was to determine the effects of rainfall, temperature, predators, parasitoids, plant age, leaf chemical composition, levels of leaf nitrogen and potassium, besides density of leaf trichomes, on attack intensity of Bemisia tabaci biotype B on the Cucumis sativus. An increase in the number of whitefly adults and nymphs per leaf was observed with plant aging. A higher number of whitefly adults per leaf and eggs cm-2 was verified in the apical part than in the middle and bottom part of the plants canopy. However, the higher number of whitefly nymphs was observed in the mid-part than in the apical and bottom part of the plant canopy. The incidence of whitefly nymphs was negatively affected with foliar nitrogen. Pentacosane and octacosane positively affected whitefly adults and the first compound also affected the nymphs of this pest species.O objetivo deste trabalho foi determinar os efeitos de pluviosidade, temperatura, predadores, parasitóides, idade de planta, composição química foliar, níveis de nitrogênio e potássio foliares, assim como de densidade de tricomas, na intensidade de ataque de Bemisia tabaci biótipo B em Cucumis sativus. Observaram-se maiores números de adultos e de ninfas de mosca-branca por folha com o aumento de idade de plantas. Adultos por folha e ovos cm-2 foram encontrados com maior freqüência na parte apical do que na parte mediana e basal do dossel das plantas. Entretanto, observou-se maior número de ninfas desse inseto no terço mediano do que nos terços apical e basal. Nitrogênio foliar afetou negativamente ninfas de mosca-branca. Pentacosano e octacosano afetaram positivamente adultos e o primeiro composto afetou também as ninfas dessa praga.

  10. Taxonomic Status of the Bemisia tabaci Complex (Hemiptera: Aleyrodidae) and Reassessment of the Number of Its Constituent Species

    OpenAIRE

    Lee, Wonhoon; Park, Jongsun; Lee, Gwan-Seok; Lee, Seunghwan; Akimoto, Shin-ichi

    2013-01-01

    Bemisia tabaci (Hemiptera: Aleyrodidae) is one of the most important insect pests in the world. In the present study, the taxonomic status of B. tabaci and the number of species composing the B. tabaci complex were determined based on 1059 COI sequences of B. tabaci and 509 COI sequences of 153 hemipteran species. The genetic divergence within B. tabaci was conspicuously higher (on average, 11.1%) than interspecific genetic divergence within the respective genera of the 153 species (on averag...

  11. Densities of Eggs and Nymphs and Percent Parasitism of Bemisia tabaci (Hemiptera: Aleyrodidae on Common Weeds in West Central Florida

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    Hugh A. Smith

    2014-11-01

    Full Text Available The density of eggs and nymphs of Bemisia tabaci (Gennadius biotype B and the percent parasitism of the nymphs were measured from specimens collected on nine species of weeds, commonly found in west central Florida during the spring and summer of 2012 and 2013. The weeds were direct seeded in 2012 and grown as transplants in 2013 for Randomized Complete Block design experiments. The leaf area of each whole-plant sample was measured and the B. tabaci density parameters were converted to numbers per 100 cm2. In June and July, 2013, whole-plant samples became too large to examine entirely, thus a representative portion of a plant totaling about 1000 cm2 was sampled. Egg and nymph densities and percent parasitism varied greatly among weed species, and were higher overall in 2012 than in 2013. The highest densities of eggs and nymphs were measured on Abutilon theophrasti, Cassia obtusifolia and Emilia fosbergii each year. Lower densities of immature B. tabaci were measured on most dates for Amaranthus retroflexus, Bidens alba, Ipomoea lacunosa, Sesbania exaltata and Sida acuta. Nymph to egg ratios of 1:4 were observed on A. theophrasti and S. exaltata in 2012, while less than one nymph per ten eggs was observed overall on A. retroflexus, E. fosbergii and I. lacunosa. In 2012, parasitism rates of 32.3% were measured for B. alba, 23.4% for C. obtusifolia and 17.5% for S. acuta. Of the 206 parasitoids reared out over two seasons, 96.6% were Encarsia spp. and the remainder Eretmocerus spp. The role of weeds in managing B. tabaci is discussed.

  12. Densities of Eggs and Nymphs and Percent Parasitism of Bemisia tabaci (Hemiptera: Aleyrodidae) on Common Weeds in West Central Florida.

    Science.gov (United States)

    Smith, Hugh A; Nagle, Curtis A; Evans, Gregory A

    2014-01-01

    The density of eggs and nymphs of Bemisia tabaci (Gennadius) biotype B and the percent parasitism of the nymphs were measured from specimens collected on nine species of weeds, commonly found in west central Florida during the spring and summer of 2012 and 2013. The weeds were direct seeded in 2012 and grown as transplants in 2013 for Randomized Complete Block design experiments. The leaf area of each whole-plant sample was measured and the B. tabaci density parameters were converted to numbers per 100 cm². In June and July, 2013, whole-plant samples became too large to examine entirely, thus a representative portion of a plant totaling about 1000 cm² was sampled. Egg and nymph densities and percent parasitism varied greatly among weed species, and were higher overall in 2012 than in 2013. The highest densities of eggs and nymphs were measured on Abutilon theophrasti, Cassia obtusifolia and Emilia fosbergii each year. Lower densities of immature B. tabaci were measured on most dates for Amaranthus retroflexus, Bidens alba, Ipomoea lacunosa, Sesbania exaltata and Sida acuta. Nymph to egg ratios of 1:4 were observed on A. theophrasti and S. exaltata in 2012, while less than one nymph per ten eggs was observed overall on A. retroflexus, E. fosbergii and I. lacunosa. In 2012, parasitism rates of 32.3% were measured for B. alba, 23.4% for C. obtusifolia and 17.5% for S. acuta. Of the 206 parasitoids reared out over two seasons, 96.6% were Encarsia spp. and the remainder Eretmocerus spp. The role of weeds in managing B. tabaci is discussed. PMID:26462945

  13. Tomato yellow leaf curl virus alters the host preferences of its vector Bemisia tabaci

    OpenAIRE

    Fang, Yong; Jiao, Xiaoguo; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Shi, Xiaobin; Chen, Gong; Su, Qi; Yang, Xin; Pan, Huipeng; Zhang, Youjun

    2013-01-01

    Bemisia tabaci, the whitefly vector of Tomato yellow leaf curl virus (TYLCV), seriously reduces tomato production and quality. Here, we report the first evidence that infection by TYLCV alters the host preferences of invasive B. tabaci B (Middle East-Minor Asia 1) and Q (Mediterranean genetic group), in which TYLCV-free B. tabaci Q preferred to settle on TYLCV-infected tomato plants over healthy ones. TYLCV-free B. tabaci B, however, preferred healthy tomato plants to TYLCV-infected plants. I...

  14. 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.

  15. Bemisia tabaci B-Arabidopsis Interactions Examined by Electrical Penetration Graphs

    OpenAIRE

    Zhou, Jaclyn Shuzhen

    2014-01-01

    In the absence of strong resistance mechanisms to control the world-wide pest Bemisia tabaci B, new methods for control must be derived from understanding the plant innate immune response to whiteflies. Using four Arabidopsis defense-signaling mutants, transcriptome and hormone treatment studies, it was shown that B. tabaci B activates SA-regulated defenses, suppresses JA-regulated defenses, and the JA-defenses are effective in slowing whitefly nymphal development. Here we used the Ele...

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

    OpenAIRE

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

    2015-01-01

    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 volatil...

  17. Developing conversed microsatellite markers and their implications in evolutionary analysis of the Bemisia tabaci complex

    OpenAIRE

    Hua-Ling Wang; Jiao Yang; Boykin, Laura M.; Qiong-Yi Zhao; Yu-Jun Wang; Shu-Sheng Liu; Xiao-Wei Wang

    2014-01-01

    The study of population genetics among the Bemisia tabaci complex is limited due to the lack of conserved molecular markers. In this study, 358, 433 and 322 new polynucleotide microsatellites are separately identified from the transcriptome sequences of three cryptic species of the B. tabaci complex. The cross species transferability of 57 microsatellites was then experimentally validated. The results indicate that these markers are conserved and have high inter-taxon transferability. Thirtee...

  18. Spatial and host-plant partitioning between coexisting Bemisia tabaci cryptic species in Tunisia

    OpenAIRE

    Saleh, D; Laarif, A.; clouet, C.; Gauthier, Nathalie

    2012-01-01

    The whitefly Bemisia tabaci is a species complex including at least 24 morphologically indistinguishable species among which the Mediterranean (Med) and Middle East-Asia Minor I (MEAMI) species containing the biotypes commonly known as Q and B, respectively. These B and Q biotypes (hereafter referred to as MEAMI and Med species) are the most invasive agricultural pests of the B. tabaci complex worldwide. The spread of MEAMI and more recently of Med species into regions already invaded by othe...

  19. Twelve new polymorphic microsatellite loci and PCR multiplexing in the whitefly, Bemisia tabaci

    OpenAIRE

    Gauthier, Nathalie; Dalleau-Clouet, C.; Bouvret, M. E.

    2008-01-01

    Twelve new dinucleotide microsatellite loci of the whitefly, Bemisia tabaci, were obtained from enriched genomic libraries. Three polymerase chain reaction multiplex sets comprising three, five and four loci were optimized and characterized across 133 B. tabaci females from Israeli rearings and natural populations collected in four Mediterranean countries (Tunisia, France, Spain and Morocco). There were three to 24 alleles per locus and the observed heterozygosity was from 0.084 to 0.420. Dev...

  20. Isolation and identification of culturable bacteria from honeydew of whitefly, Bemisia tabaci (G.) (Hemiptera: Aleyrodidae)

    OpenAIRE

    Roopa H.K.; Rebijith K.B.; Asokan R.; Riaz Mahmood; Krishna Kumar N.K.

    2014-01-01

    Bemisia tabaci (G.) is an important pest and a vector of Gemini viruses infecting plants. During the process of feeding B. tabaci excretes honeydew which is rich in nutrients, and an excellent medium for microbial growth. Recent report proved that volatile emitted by the honeydew associated bacteria of aphid, Acyrthosiphon pisum Harris was involved in natural enemy calling. Thus understanding the honeydew associated bacteria is of paramount importance from the non-chemical method of insect pe...

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

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    ANTONIO PANCRÁCIO DE SOUZA

    2000-01-01

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

  2. First report of the Q biotype of Bemisia tabaci in Argentina and Uruguay

    OpenAIRE

    Grille, G.; Gauthier, Nathalie; Buenahora, J.; Basso, C; Bonato, Olivier

    2011-01-01

    Bemisia tabaci adults were collected from pepper and melon at different commercial production greenhouses in Argentina and Uruguay. The biotype status of adults was then established using cytochrome oxidase I gene (mtCOI) as molecular marker. Only the Q biotype was found on all plants sampled. This is the first report of the Q biotype in Argentina and Uruguay.

  3. Draft Genome Sequence of Rickettsia sp. Strain MEAM1, Isolated from the Whitefly Bemisia tabaci

    OpenAIRE

    Rao, Qiong; Wang, Shuang; Zhu, Dan-Tong; Wang, Xiao-Wei; Liu, Shu-Sheng

    2012-01-01

    We report the draft genome sequence of the Rickettsia sp. strain MEAM1, which is a facultative symbiont from an invasive species of the whitefly Bemisia tabaci. The total length of the assembled genome is approximately 1.24 Mb, with 335 scaffolds and 1,247 coding sequences predicted within the genome.

  4. Insecticidal Activity of Chromobacterium subtsugae on the Sweet Potato Whitefly, Bemisia tabaci, Biotype B

    Science.gov (United States)

    Chromobacterium subtsugae crude extracts contain compounds that are toxic to nymphal and adult Bemisia tabaci. When fed on artificial diet containing 10% of the supernatant of an aqueous cell-free extract of C subtsugae, the number of 2nd and 4th instar nymphs and of emerged adults was significantl...

  5. Identification and characterization of functional aquaporin water channel protein from alimentary tract of whitefly, Bemisia tabaci

    Science.gov (United States)

    Some hemipteran xylem and phloem feeding insects have evolved specialized alimentary structures or filter chambers that rapidly transport water for excretion or osmoregulation. In the whitefly, Bemisia tabaci, mass movement of water through opposing alimentary tract tissues within the filter chamber...

  6. Aerial electrostatic-charged spray for deposition and efficacy against sweetpotato whitefly (Bemisia tabaci) on cotton

    Science.gov (United States)

    Efficacy of aerial electrostatic-charged sprays was evaluated for spray deposit characteristics and season-long control of sweet potato whitefly (SWF), Bemisia tabaci biotype B (a.k.a. B. argentifolii), in an irrigated 24-ha cotton field. Treatments included electrostatic-charged sprays at full and ...

  7. Molecular Characterization of Vitellogenin and Vitellogenin Receptor of Bemisia tabaci

    Science.gov (United States)

    Upadhyay, Santosh Kumar; Singh, Harpal; Dixit, Sameer; Mendu, Venugopal; Verma, Praveen C.

    2016-01-01

    Vitellogenin (Vg) plays vital role in oocytes and embryo development in insects. Vg is synthesized in the fat body, moves through haemolymph and accumulates in oocytes. Vitellogenin receptors (VgR) present on the surface of oocytes, are responsible for Vg transportation from haemolymph to oocytes. Here, we cloned and characterized these genes from Bemisia tabaci Asia1 (BtA1) species. The cloned BtA1Vg and BtA1VgR genes consisted of 6,330 and 5,430 bp long open reading frames, which encoded 2,109 and 1,809 amino acid (AA) residues long protein. The BtA1Vg protein comprised LPD_N, DUF1943 and VWFD domains, typical R/KXXR/K, DGXR and GL/ICG motifs, and polyserine tracts. BtA1VgR protein contained 12 LDLa, 10 LDLb and 7 EGF domains, and a trans-membrane and cytoplasmic region at C-terminus. Phylogenetic analyses indicated evolutionary association of BtA1Vg and BtA1VgR with the homologous proteins from various insect species. Silencing of BtA1VgR by siRNA did not affect the transcript level of BtA1Vg. However, BtA1Vg protein accumulation in oocytes was directly influenced with the expression level of BtA1VgR. Further, BtA1VgR silencing caused significant mortality and reduced fecundity in adult whiteflies. The results established the role of BtA1VgR in transportation of BtA1Vg in oocytes. Further, these proteins are essential for fecundity, and therefore these can be potential RNAi targets for insect control in crop plants. PMID:27159161

  8. Molecular Characterization of Vitellogenin and Vitellogenin Receptor of Bemisia tabaci.

    Science.gov (United States)

    Upadhyay, Santosh Kumar; Singh, Harpal; Dixit, Sameer; Mendu, Venugopal; Verma, Praveen C

    2016-01-01

    Vitellogenin (Vg) plays vital role in oocytes and embryo development in insects. Vg is synthesized in the fat body, moves through haemolymph and accumulates in oocytes. Vitellogenin receptors (VgR) present on the surface of oocytes, are responsible for Vg transportation from haemolymph to oocytes. Here, we cloned and characterized these genes from Bemisia tabaci Asia1 (BtA1) species. The cloned BtA1Vg and BtA1VgR genes consisted of 6,330 and 5,430 bp long open reading frames, which encoded 2,109 and 1,809 amino acid (AA) residues long protein. The BtA1Vg protein comprised LPD_N, DUF1943 and VWFD domains, typical R/KXXR/K, DGXR and GL/ICG motifs, and polyserine tracts. BtA1VgR protein contained 12 LDLa, 10 LDLb and 7 EGF domains, and a trans-membrane and cytoplasmic region at C-terminus. Phylogenetic analyses indicated evolutionary association of BtA1Vg and BtA1VgR with the homologous proteins from various insect species. Silencing of BtA1VgR by siRNA did not affect the transcript level of BtA1Vg. However, BtA1Vg protein accumulation in oocytes was directly influenced with the expression level of BtA1VgR. Further, BtA1VgR silencing caused significant mortality and reduced fecundity in adult whiteflies. The results established the role of BtA1VgR in transportation of BtA1Vg in oocytes. Further, these proteins are essential for fecundity, and therefore these can be potential RNAi targets for insect control in crop plants. PMID:27159161

  9. Interaction between resistant tomato genotypes and plant extracts on Bemisia tabaci (Genn. biotype B Interação de genótipos resistentes de tomateiro e extratos vegetais sobre Bemisia tabaci (Genn. biótipo B

    Directory of Open Access Journals (Sweden)

    Edson Luiz Lopes Baldin

    2007-10-01

    Full Text Available The tomato (Lycopersicon spp. productivity is severely reduced by attack of several insects and microorganisms. It is economically one of the most important crops that has been extensively cultivated in the Americas. Therefore, assays were performed in the greenhouse and the laboratory to evaluate the possible interaction between resistant tomato genotypes and plant extracts on the control of the pest Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae biotype B. This evaluation was performed for genotypes IAC-Santa Clara, PI-134417, LA-716, PI-134418, and PI-127826, and aqueous extracts from seeds of Azadirachta indica A. de Jussieu (Rutales: Meliaceae, branches and leaves of Trichilia pallida Swartz (Rutales: Meliaceae. In the greenhouse, spraying with extracts from seeds of A. indica, and leaves and branches of T. pallida reduced whitefly attraction with IAC-Santa Clara; on PI-134417, LA-716, PI-134418, and PI-127826 the extracts did not affect the attractiveness to the B. tabaci biotype B. Extracts from A. indica seeds and T. pallida leaves and branches reduced oviposition on IAC-Santa Clara; extracts from T. pallida branches reduced oviposition on PI-134417, PI-134418, and PI-127826, while the extract from A. indica seeds reduced oviposition in PI-127826. The extracts did not affect oviposition on LA-716. In the laboratory, the extracts increased the mortality of nymphs on the genotypes. The "genotype × extract" interaction was significant, indicating an addictive effect between resistant genotypes and plant extracts on whitefly control.O tomate (Lycopersicon spp. é uma das hortaliças mais importantes do mundo em termos econômicos e tem sido extensivamente cultivado nas Américas há séculos. Entretanto, a produtividade poderia ser mais alta se ela não fosse suscetível a ataques de insetos e microorganismos. Foram realizados ensaios em casa-de-vegetação e laboratório visando avaliar a possível interação de genótipos de tomateiro

  10. Encarsia species (Hymenoptera: Aphelinidae) of Australia and the Pacific Islands attacking Bemisia tabaci and Trialeurodes vaporariorum (Hemiptera: Aleyrodidae)--a pictorial key and descriptions of four new species.

    Science.gov (United States)

    Schmidt, S; Naumann, I D; De Barro, P J

    2001-10-01

    After the recent introduction of the pest whitefly Bemisia tabaci (Gennadius) biotype B into Australia, research was undertaken to study the parasitoids of the long established native B. tabaci and Trialeurodes vaporariorum (Westwood). The genus Encarsia contains species which are important biological control agents of whiteflies and hard scales. The taxonomy of the Encarsia species attacking B. tabaci and T. vaporariorum in Australia and the Pacific Islands is revised. DNA sequencing of the 28S D2 ribosomal DNA was used to characterize species. Sixteen species are recognized, with 12 occurring in Australia, eight in the Pacific region, and four in both regions. All except one species (E. formosa Gahan) are new records for Australia. Four species are described as new from Australia: E. accenta Schmidt & Naumann sp. n., E. adusta Schmidt & Naumann sp. n., E. oakeyensis Schmidt & Naumann sp. n., and E. ustulata Schmidt & Naumann sp. n. Diagnostic descriptions are given for all species and each species is illustrated. A pictorial key is provided to allow the identification of species by non-specialists. PMID:11583600

  11. A knottin-like putative antimicrobial gene family in the Whitefly Bemisia tabaci B: cloning and transcript regulation

    Science.gov (United States)

    The whitefly, Bemisia tabaci, is a worldwide plant pest and the vector of agriculturally important plant pathogenic begomoviruses. Of two vectored begomoviruses, Tomato yellow leaf curl virus (TYLCV) is transcriptionally active in B. tabaci and Tomato mottle virus (ToMoV)is not. Comparative analyses...

  12. Genome Sequences of the Primary Endosymbiont “Candidatus Portiera aleyrodidarum” in the Whitefly Bemisia tabaci B and Q Biotypes

    OpenAIRE

    Jiang, Zi-Feng; Xia, Fangfang; Johnson, Kipp W.; Bartom, Elizabeth; Tuteja, Jigyasa H.; Stevens, Rick; Grossman, Robert L; Brumin, Marina; White, Kevin P.; Ghanim,Murad

    2012-01-01

    “Candidatus Portiera aleyrodidarum” is the obligate primary endosymbiotic bacterium of whiteflies, including the sweet potato whitefly Bemisia tabaci, and provides essential nutrients to its host. Here we report two complete genome sequences of this bacterium from the B and Q biotypes of B. tabaci.

  13. Draft Genome Sequence of “Candidatus Hamiltonella defensa,” an Endosymbiont of the Whitefly Bemisia tabaci

    OpenAIRE

    Rao, Qiong; Wang, Shuang; Su, Yun-Lin; Bing, Xiao-Li; Liu, Shu-Sheng; Wang, Xiao-Wei

    2012-01-01

    “Candidatus Hamiltonella defensa” is a facultative endosymbiont of the whitefly Bemisia tabaci. Herein, we report the first draft genome sequence of “Candidatus Hamiltonella defensa” from the invasive Mediterranean cryptic species of the B. tabaci complex. The 1.84-Mbp genome sequence comprises 404 contigs and contains 1,806 predicted protein-coding genes.

  14. Mechanisms of inter- and intra-specific competitive replacement by the Bemisia tabaci B biotype (Homoptera: Aleyrodidae)

    OpenAIRE

    Jinyan Liu; Guifen Zhang; Fanghao Wan; Jinjun Wang

    2008-01-01

    The B biotype of Bemisia tabaci, sometimes called a “super bug”, has been one of this species complex’s most harmful biotypes because of the tremendous damage it inflicts worldwide. Recently, competitivedisplacement of pre-existent biotypes and other herbivores by the B. tabaci B biotype has been observed in many regions worldwide. Based on literature review, the mechanisms responsible for competitive replacement by B. tabaci may include exploitation or interference competition, which involve...

  15. Special Issue Introduction- The Whitefly Bemisia tabaci Species Complex and Begomoviruses: Research Progress and Future Prospects

    Institute of Scientific and Technical Information of China (English)

    LIU Shu-sheng; Linda L Walling; WANG Xiao-wei

    2012-01-01

    The whitefly Bemisia tabaci species complex and the begomoviruses they transmit are devastating agricultural pests worldwide.With the rapid and further invasions by some members of the whitefly species complex into new regions,their impacts on human society are likely to increase in the years to come.This special issue of the Journal of Integrative Agriculture is devoted to these two groups of interacting organisms.The initial inspiration for this special issue came from the International Symposium on Future Directions in Bemisia Research held in Hangzhou,China,in October 2010.The symposium was organized by the Institute of Insect Sciences and the Institute of Biotechnology of Zhejiang University,China,in an effort to promote information exchange and international collaborative research on a few key aspects of the biology of B.tabaci.

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

    OpenAIRE

    André Luiz Lourenção; Hiroshi Nagai

    1994-01-01

    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 lavour...

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

    OpenAIRE

    Carlos Enrique Ail-Catzim; Alejandro Manelik García-López; Rosalba Troncoso-Rojas; Rosario Esmeralda González-Rodríguez; Yuliana Sánchez-Segura

    2015-01-01

    T he use of repeated insecticide applications in agricultural crops to control Bemisia tabaci (Genn.) has resulted in resistance problems and environmental pollution. Inputs from plant species are an alternative to reduce this problem. Plants are a source of bioactive chemicals that can have insecticidal, repellent, attractant, anti-feeding or growth regulator effects. The aim of this study was to determine the insecticidal and repellent activity of ethanolic, acetonic and aqueous extracts of...

  18. Naturally occurring bioactive compounds from four repellent essential oils against Bemisia tabaci whiteflies

    OpenAIRE

    Deletre, E.; Chandre, Fabrice; Barkman, B.; Menut, C.; Martin, T.

    2016-01-01

    BACKGROUNDIn tropical countries, netting is an effective sustainable tool for protecting horticultural crops against Lepidoptera, although not against small pests such as Bemisia tabaci, while smaller mesh netting can be used in temperate regions. A solution is to combine a net with a repellent. Previously we identified repellent essential oils: lemongrass (Cymbopogon citratus), cinnamon (Cinnamomum zeylanicum), cumin (Cuminum cyminum) and citronella (Cymbopogon winternarius). The present stu...

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

    OpenAIRE

    Esmaeily Saeideh; Samih Mohammad Amin; Zarabi Mehdi; Jafarbeigi Fatemeh

    2014-01-01

    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 lowes...

  20. 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, s

  1. 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.

  2. Parasitization by the wasp Eretmocerus mundus induces transcription of genes related to immune response and symbiotic bacteria proliferation in the whitefly Bemisia tabaci

    Directory of Open Access Journals (Sweden)

    Czosnek Henryk

    2008-07-01

    Full Text Available Abstract Background The whitefly Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae, and the viruses it transmits, are a major constraint to growing vegetable crops worldwide. Although the whitefly is often controlled using chemical pesticides, biological control agents constitute an important component in integrated pest management programs, especially in protected agriculture. One of these agents is the wasp Eretmocerus mundus (Mercet (Hymenoptera: Aphelinidae. E. mundus lays its egg on the leaf underneath the second-third instar nymph of B. tabaci. First instars of the wasp hatch and penetrate the whitefly nymphs. Initiation of parasitization induces the host to form a capsule composed of epidermal cells around the parasitoid. The physiological and molecular processes underlying B. tabaci-E. mundus interactions have never been investigated. Results We used a cDNA microarray containing 6,000 expressed sequence tags (ESTs from the whitefly genome to study the parasitoid-whitefly interaction. We compared RNA samples collected at two time points of the parasitization process: when the parasitoid first instar starts the penetration process and once it has fully penetrated the host. The results clearly indicated that genes known to be part of the defense pathways described in other insects are also involved in the response of B. tabaci to parasitization by E. mundus. Some of these responses included repression of a serine protease inhibitor (serpin and induction of a melanization cascade. A second set of genes that responded strongly to parasitization were bacterial, encoded by whitefly symbionts. Quantitative real-time PCR and FISH analyses showed that proliferation of Rickettsia, a facultative secondary symbiont, is strongly induced upon initiation of the parasitization process, a result that supported previous reports suggesting that endosymbionts might be involved in the insect host's resistance to various environmental stresses. Conclusion This

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

    Directory of Open Access Journals (Sweden)

    Aline R. Rabello

    2008-01-01

    Full Text Available 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 distinguished from the BR individuals. A phylogenetic tree based on ITS1 rDNA sequence was constructed. This is the first report of the ITS1 rDNA sequence of Bemisia tuberculata and of the BR biotype of B. tabaci.

  4. Host plants and natural enemies of Bemisia tabaci (Hemiptera: Aleyrodidae)in China

    Institute of Scientific and Technical Information of China (English)

    Shao-Jian Li; Xia Xue; Muhammad Z.Ahmed; Shun-Xiang Ren; Yu-Zhou Du; Jian-Hui Wu; Andrew G.S.Cuthbertson; Bao-Li Qiu

    2011-01-01

    The sweetpotato whitefly,Bemisia tabaci,has been a destructive pest in China for over the past two decades.It is an extremely polyphagous insect,being recorded feeding on hundreds of host plants around the world.Potential host plants and natural enemies of B.tabaci in the south,southeast,middle,north and northwest of China were investigated during the last decade.In total 361 plant species from 89 families were recorded in our surveys.Plants in the families Compositae,Cruciferae,Cucurbitaceae,Solanaceae and Leguminosae were the preferred host species for B.tabaci,which therefore suffered much damage from this devastating pest due to their high populations.In total,56 species of parasitoids,54 species of arthropod predators and seven species of entomopathogenic fungi were recorded in our surveys.Aphelinid parasitoids from Encarsia and Eretmocerus genera,lady beetles and lacewings in Coleoptera and Neuroptera were found to be the dominant arthropod predators of B.tabaci in China.The varieties of host plant,their distribution and the dominant species of natural enemies of B.tabaci in different regions of China are discussed.

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

    International Nuclear Information System (INIS)

    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)

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

    OpenAIRE

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

    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...

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

    OpenAIRE

    He, Yuxian; Zhao, Jianwei; Zheng, Yu; Weng, Qiyong; Biondi, Antonio; DESNEUX, Nicolas

    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...

  8. Antifeedant activity of botanical crude extracts and their fractions on Bemisia tabaci (Homoptera: Aleyrodidae) adults: III. Quassia amara (Simaroubaceae)

    OpenAIRE

    Guillermo Flores; Luko Hilje; Gerardo A Mora; Manuel Carballo

    2008-01-01

    Bemisia tabaci is a key virus vector on several crops worldwide. Then, 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 bitterwood (Quassia amara, Simaroubaceae) were tested for phagodeterrence to B. tabaci adults under greenhouse conditions, on tomato plants, in Costa Rica...

  9. Rapid accumulation and low degradation: key parameters of Tomato yellow leaf curl virus persistence in its insect vector Bemisia tabaci

    OpenAIRE

    Nathalie Becker; Loup Rimbaud; Frédéric Chiroleu; Bernard Reynaud; Gaël Thébaud; Jean-Michel Lett

    2015-01-01

    Of worldwide economic importance, Tomato yellow leaf curl virus (TYLCV, Begomovirus) is responsible for one of the most devastating plant diseases in warm and temperate regions. The DNA begomoviruses (Geminiviridae) are transmitted by the whitefly species complex Bemisia tabaci. Although geminiviruses have long been described as circulative non-propagative viruses, observations such as long persistence of TYLCV in B. tabaci raised the question of their possible replication in the vector. We m...

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

    OpenAIRE

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

    2015-01-01

    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 detoxi...

  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. Scientific Opinion on the risks to plant health posed by Bemisia tabaci species complex and viruses it transmits for the EU territory

    OpenAIRE

    EFSA Panel on Plant Health (PLH)

    2013-01-01

    The Panel on Plant Health conducted a pest risk assessment for Bemisia tabaci and the viruses it transmits, including an evaluation of risk reduction options and an assessment of the effectiveness of the special requirements linked to B. tabaci and the viruses listed in Council Directive 2000/29/EC. B. tabaci and a large number of viruses transmitted by this polyphagous insect occur in subtropical and tropical climates around the world. Five entry pathways for B. tabaci and associated viruses...

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

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    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.

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

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    Francisco das Chagas Vidal Neto

    2008-02-01

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

  16. Modelling temperature-dependent bionomics of Bemisia tabaci (Q-biotype)

    OpenAIRE

    Bonato, Olivier; Lurette, A.; Vidal, Claire; Fargues, J.

    2007-01-01

    The influence of temperature (17, 21, 25, 30 and 35 degrees C) on life-history traits of a Q-biotype Bemisia tabaci population on tomato is studied. Temperature-dependent relationships are characterized for immature developmental rate, immature survival, fecundity, longevity and intrinsic rate of increase. Development time vary from 20 days at 30 degrees C to 56 days at 17 degrees C and the lowest thermal threshold is estimated at 10.2 degrees C. The optimal temperature for immature developme...

  17. HOST SPECIFIC MOLECULAR VARIATIONS IN BEMISIA TABACI (G. AS REVEALED BY USING MITOCHONDRIAL AND RIBOSOMAL MARKER

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    R. ELLANGO

    2014-06-01

    Full Text Available Bemisia tabaci is globally important pest and also vector of Gemini viruses on various economically important crops worldwide. Presently there are lots of debates going on the species status and cryptic nature of this species which is complex as challenging. Therefore, in this study we analysed the genetic diversity of B. tabaci (18 samples collected on various host plants. The diversity analysis was performed using two well known markers such as mitochondrial COI gene and the ribosomal ITS1. The phylogenetic trees were constructed separately for two dataset using Neighbor-Joining method. Our result confirmed presence of four putative species of B. tabaci such as Asia I, Asia II 1, Asia II 5 and Asia II 8 in India. The Asia I genetic group found most widely distributed and shows relatively polyphagus, which has mtCOI consensus sequence identity of 84.32% to 86.76% with Asia II sub groups. Our work has shown the genetic boundary of B. tabaci which helped in understanding host specificity across Karnataka, India.

  18. Genome sequencing and analysis of the whitefly (Bemisia tabaci) MEAM1, one of the most important vectors for plant viruses

    Science.gov (United States)

    Among whiteflies, the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex is particularly important because of its ability to transmit hundreds of plant viruses, resulting in the loss of billions of U.S. dollars on agronomically important crops such as tomato, cucurbits, cassava, and cotton worl...

  19. Taxonomic status of the Bemisia tabaci complex (Hemiptera: Aleyrodidae and reassessment of the number of its constituent species.

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    Wonhoon Lee

    Full Text Available Bemisia tabaci (Hemiptera: Aleyrodidae is one of the most important insect pests in the world. In the present study, the taxonomic status of B. tabaci and the number of species composing the B. tabaci complex were determined based on 1059 COI sequences of B. tabaci and 509 COI sequences of 153 hemipteran species. The genetic divergence within B. tabaci was conspicuously higher (on average, 11.1% than interspecific genetic divergence within the respective genera of the 153 species (on average, 6.5%. This result indicates that B. tabaci is composed of multiple species that may belong to different genera or subfamilies. A phylogenetic tree constructed based on 212 COI sequences without duplications revealed that the B. tabaci complex is composed of a total of 31 putative species, including a new species, JpL. However, genetic divergence within six species (Asia II 1, Asia II 7, Australia, Mediterranean, New World, and Sub Saharan Africa 1 was higher than 3.5%, which has been used as a threshold of species boundaries within the B. tabaci complex. These results suggest that it is necessary to increase the threshold for species boundaries up to 4% to distinguish the constituent species in the B. tabaci complex.

  20. 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.

  1. Endosymbiont metacommunities, mtDNA diversity and the evolution of the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex.

    Science.gov (United States)

    Gueguen, Gwénaelle; Vavre, Fabrice; Gnankine, Olivier; Peterschmitt, Michel; Charif, Delphine; Chiel, Elad; Gottlieb, Yuval; Ghanim, Murad; Zchori-Fein, Einat; Fleury, Frédéric

    2010-10-01

    Bemisia tabaci, an invasive pest that causes crop damage worldwide, is a highly differentiated species complex, divided into biotypes that have mainly been defined based on mitochondrial DNA sequences. Although endosymbionts can potentially induce population differentiation, specialization and indirect selection on mtDNA, studies have largely ignored these influential passengers in B. tabaci, despite as many as seven bacterial endosymbionts have been identified. Here, we investigate the composition of the whole bacterial community in worldwide populations of B. tabaci, together with host genetic differentiation, focusing on the invasive B and Q biotypes. Among 653 individuals studied, more than 95% of them harbour at least one secondary endosymbiont, and multiple infections are very common. In addition, sequence analyses reveal a very high diversity of facultative endosymbionts in B. tabaci, with some bacterial genus being represented by more than one strain. In the B and Q biotypes, nine different strains of bacteria have been identified. The mtDNA-based phylogeny of B. tabaci also reveals a very high nucleotide diversity that partitions the two ITS clades (B and Q) into six CO1 genetic groups. Each genetic group is in linkage disequilibrium with a specific combination of endosymbionts. All together, our results demonstrate the rapid dynamics of the bacterial endosymbiont-host associations at a small evolutionary scale, questioning the role of endosymbiotic communities in the evolution of the Bemisia tabaci species complex and strengthening the need to develop a metacommunity theory of inherited endosymbionts. PMID:20723069

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

    Directory of Open Access Journals (Sweden)

    Huipeng Pan

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

  3. 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

    2015-01-01

    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. PMID:26334135

  4. Bemisia tabaci, Brevicoryne brassicae and Thrips tabaci abundance on Brassica oleracea var. acephala Abundância de Bemisia tabaci, Brevicoryne brassicae e Thrips tabaci em Brassica oleracea var. acephala

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    Germano Leão Demolin Leite

    2005-03-01

    Full Text Available Kale Brassica oleracea var. acephala is attacked by whitefly Bemisia tabaci, aphid Brevicoryne brassicae and Thrips tabaci. One of the main reasons for extensive insecticide application is the lack of information about factors that control insect population. The objectives of this study were to investigate the relationships between predators and parasitoids, organic compound leaves, levels of leaf nitrogen and potassium, total rainfall, relative humidity, sunlight and median temperature on the abundance of whitefly, aphid, and thrips in kale genotype "Talo Roxo". The beating tray method, direct counting and magnifying lens were used to estimate the number of these pests, predators and parasitoids. Median temperature, sunlight and relative humidity correlated to the amount of leaf nonacosane, which in turn was associated with aphids population increase. A tendency in the reduction of aphids and thrips populations with increase in total rainfall was observed. The whitefly can be a harmful pest in kale producing regions of higher temperature and smaller rainfall. In regions which present moderate temperature, where there is a high incidence of aphids, genotype with low leaf wax content should be chosen. Natural enemies, especially the parasitoid Adialytus spp., can control agents of the aphids population in kale.A couve, Brassica oleracea var. acephala, é atacada por mosca-branca Bemisia tabaci, pulgão Brevicoryne brassicae e tripes Thrips tabaci. Uma das principais razões para o uso intensivo de inseticidas é a falta de informação sobre os fatores que controlam a população de insetos. O objetivo deste estudo foi investigar as relações entre predadores e parasitóides, compostos orgânicos foliares, níveis foliares de nitrogênio e de potássio, pluviosidade total, umidade relativa, insolação e temperatura média na abundância da mosca-branca, pulgões e tripes em couve genótipo Talo Roxo. Foi usado o método da batida em bandeja

  5. 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. PMID:26470209

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

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    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.

  7. Potential of two populations of Amblyseius swirskii (Acari: Phytoseiidae) for the control of Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) in Brazil.

    Science.gov (United States)

    Cavalcante, Ana Cristina Cerqueira; Borges, Lucas Rosa; Lourenção, André Luiz; de Moraes, Gilberto José

    2015-12-01

    Predatory mites of the family Phytoseiidae are commercialized in European and North American countries for the control of whiteflies (Insecta: Aleyrodidae). Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is one of the predators used for that purpose. This predator is not found in Brazil and in many other countries, but its introduction could promote biological control of Bemisia tabaci (Gennadius) biotype B (silverleaf whitefly) in those countries. The aim of this study was to compare two populations of A. swirskii as predators of eggs of B. tabaci of two different ages, as well as the acceptance of those populations for other food types [eggs of Tetranychus urticae Koch; larvae and protonymphs of Aleuroglyphus ovatus (Troupeau) (Astigmatina: Acaridae) and cattail pollen (Typha domingensis Persoon)]. One of the populations of A. swirskii was collected in the Republic of Benin, in tropical Africa, and the other was commercially available in The Netherlands. The comparison was done to evaluate the population with better potential for practical use, and to determine food types that could be used for mass rearing the predator. Experiments were conducted at 28 ± 1 °C, 80 ± 10 % relative humidity and 12 h photophase. Both populations were able to oviposit when fed eggs of B. tabaci, but the Netherlands population showed higher oviposition rate (2.3 and 1.6 times higher on young and older eggs, respectively). Higher predation rates were observed for eggs up to 24 h of age in comparison with older eggs. Aleuroglyphus ovatus proved to be a promising prey for possible mass rearing of this predator in Brazil, where that astigmatic mite is found naturally when pollen was used as food, no significant difference was observed for oviposition rate between populations. The results suggested a higher potential of the Netherlands population of A. swirskii for the control of B. tabaci biotype B in this country for augmentative biological control, with the possible use of

  8. Transmission of Tomato Yellow Leaf Curl Virus by Bemisia tabaci as Affected by Whitefly Sex and Biotype

    OpenAIRE

    Wenxi Ning; Xiaobin Shi; Baiming Liu; Huipeng Pan; Wanting Wei; Yang Zeng; Xinpei Sun; Wen Xie; Shaoli Wang; Qingjun Wu; Jiaxu Cheng; Zhengke Peng; Youjun Zhang

    2015-01-01

    Bemisia tabaci is a serious pest of vegetables and other crops worldwide. The most damaging and predominant B. tabaci biotypes are B and Q, and both are vectors of tomato yellow leaf curl virus (TYLCV). Previous research has shown that Q outperforms B in many respects but comparative research is lacking on the ability of B and Q to transmit viruses. In the present study, we tested the hypothesis that B and Q differ in their ability to transmit TYLCV and that this difference helps explain TYLC...

  9. Bemisia tabaci (Hemiptera: Aleyrodidae) nymphal feeding in cotton (Gossypium hirsutum) leaves

    Institute of Scientific and Technical Information of China (English)

    CHANG-CHI CHU; DENNIS A. MARGOSAN; JAMES S. BUCKNER; THOMAS P. FREEMAN; THOMAS J. HENNEBERRY

    2007-01-01

    We used brightfield electron microscopy (BEM), differential interference contrast microscopy (DICM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and confocal laser scanning microscopy (CLSM) to investigate the stylet pathways of Bemisia tabaci during nymphal feeding behavior in cotton leaves beginning with penetration of the abaxial leaf surface and ending with stylers in sieve tubes in phloem tissues. Most nymphal stylets within salivary sheaths penetrating leaf tissues made complex turns and developed more than one salivary sheath branch before ending in sieve tubes. The external morphology of the salivary sheaths and their routes between and through leaf cells are described during the present study. Results showed the presence of the stylet within the sieve tubes. B. tabaci nymphs may remove stylets and feed in different sieve tubes.Ten short movies showing the progression of the stylet penetrations from adaxial surface to the sieve tubes are attached to Figures 8-15. The report and movies can be viewed from the internet. Download the movies to a local drive in your compute rfirs tfor fast upload. The movies are posted on theweb sitehttp ://www.ars.usda.gov/Services/docs.htm? docid= 14629.The movies can be used as a teaching aid in biology classes.

  10. Codon Usage Bias in Two Hemipteran Insect Species: Bemisia tabaci and Homalodisca coagulata

    Directory of Open Access Journals (Sweden)

    Jyotika Sharma

    2014-01-01

    Full Text Available Codon bias is the nonuniform use of synonymous codons which encode the same amino acid. Some codons are more frequently used than others in several organisms, particularly in the highly expressed genes. The spectacular diversity of insects makes them a suitable candidate for analyzing the codon usage bias. Recent expansion in genome sequencing of different insect species provides an opportunity for studying the codon usage bias. Several works on patterns of codon usage bias were done on Drosophila and other related species but only few works were found in Hemiptera order. We analyzed codon usage in two Hemipteran insect species namely Bemisia tabaci and Homalodisca coagulata. Most frequent codons end with A or C at the 3rd codon position. The ENC (a measure of codon bias value ranges from 43 to 60 (52.80 in B. tabaci but from 49 to 60 (56.69 in H. coagulata. In both insect species, a significant positive correlation was observed between A and A3%, C and C3%, and GC and GC3%, respectively. Our findings suggest that codon usage bias in two Hemipteran insect species is not remarkable and that mutation pressure causes the codon usage pattern in two Hemipteran insect species.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Acyl sugars and whitefly (Bemisia tabaci) resistance in segregating populations of tomato genotypes.

    Science.gov (United States)

    Dias, D M; Resende, J T V; Marodin, J C; Matos, R; Lustosa, I F; Resende, N C V

    2016-01-01

    The wild tomato, Solanum pennellii, is an important source of resistance genes against tomato pests. This resistance is due to the presence of acyl sugars (AS), which are allelochemicals that have negative effects on arthropod pests. There are no commercially available tomato cultivars that exhibit significant levels of resistance to arthropod pests. Therefore, this study evaluated resistance to whitefly (Bemisia tabaci) in F2 and F2RC1 tomato genotypes with high AS levels from a cross between Solanum lycopersicum 'Redenção' and the S. pennellii accession, LA-716. Plants were exposed to B. tabaci biotype B at the pre-flowering stage. In both generations, there were significant, negative correlations between AS content and oviposition preference and nymph development. Whitefly exhibited a lower preference for oviposition and produced fewer nymphs in genotypes with high AS levels and the wild parent S. pennellii than in the low AS-level genotypes and Redenção cultivar, demonstrating that the breeding program was effective in transferring resistance to the F2 and F2RC1 generations. RVTA-2010-pl#31 and RVTA-2010-pl#94 in the F2 population are promising genotypes that produced materials with high AS levels in the F2RC1 generation (RVTA-2010-31-pl#177 and RVTA-2010-94-pl#381). PMID:27173206

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

    International Nuclear Information System (INIS)

    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)

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

    Science.gov (United States)

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

    2016-04-01

    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 used to elucidate the genetic background of whitefly-resistance related traits and associated biochemical traits in this species. Minor quantitative trait loci (QTLs) for whitefly adult survival (AS) and oviposition rate (OR) were identified and some were confirmed in an F2 BC1 population, where they showed increased percentages of explained variance (more than 30%). Bulked segregant analyses on pools of whitefly-resistant and -susceptible F2 plants enabled the identification of metabolites that correlate either with resistance or susceptibility. Genetic mapping of these metabolites showed that a large number of them co-localize with whitefly-resistance QTLs. Some of these whitefly-resistance QTLs are hotspots for metabolite QTLs. Although a large number of metabolite QTLs correlated to whitefly resistance or susceptibility, most of them are yet unknown compounds and further studies are needed to identify the metabolic pathways and genes involved. The results indicate a direct genetic correlation between biochemical-based resistance characteristics and reduced whitefly incidence in S. pennellii. PMID:26576823

  15. Complete mitochondrial DNA genome of Bemisia tabaci cryptic pest species complex Asia I (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Tay, W T; Elfekih, S; Court, L; Gordon, K H; De Barro, P J

    2016-01-01

    The complete length of the Asia I member of the Bemisia tabaci species complex mitochondrial DNA genome (mitogenome) is 15,210 bp (GenBank accession no. KJ778614) with an A-T biased nucleotide composition (A: 32.7%; T: 42.4%; G: 14.0%; C: 10.8%). The mitogenome consists of 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNA (rRNAs) and a 467 bp putative control region which also includes the A+T rich repeat region. All PCGs have an ATA (n = 8) or ATG (n = 5) start codon. Gene synteny of Asia I is overall similar to B. afer and two other members of the B. tabaci species complex Mediterranean and New World 1, and contains the tRNA-Ser2 located between the Cytb and ND1 genes found in Mediterranean and New World 1, but which is absent in B. afer. The orientation of the tRNA-Arg in Asia I is on the "plus" strand and differed from Mediterranean which is found on the "minus" strand. The Asia I mitogenome size is currently ranked the second smallest after B. afer (14,968 bp) followed by New World 1 (15,322 bp) and Mediterranean (15,632 bp). PMID:24960562

  16. Aqueous Extracts of Some Medicinal Plants are as Toxic as Lmidacloprid to the Sweet Potato Whitefly, Bemisia tabaci

    OpenAIRE

    Ateyyat, Mazen A.; Al-Mazra'awi, Mohammad; Abu-Rjai, Talal; Shatnawi, Mohamad A.

    2009-01-01

    Aqueous extracts of nine plants, known to have medicinal activity, were tested for their toxicity against the sweet potato whitefly, Bemisia tabaci Genn. (Homoptera: Aleurodidae) compared to the toxicity of the insecticide, Imidacloprid. Extracts of Lepidiuim sativum L. (Brassicales: Brassicaceae) killed 71 % of early stage nymphs, which was not significantly different from mortality caused by Imidacloprid. Treatment of pupae with three plant extracts, L. sativum, Achillea biebersteinii L. (A...

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

    OpenAIRE

    Horacio Ballina-Gomez; Luis Latournerie-Moreno; Esau Ruiz-Sanchez; Alfonso Perez-Gutierrez; Gabriel Rosado-Lugo

    2013-01-01

    The high diversity of chili pepper (Capsicum annuum L.) in Mexico offers an excellent alternative to search for wild and semi-domesticated genotypes as sources of resistance to the complex Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae)-Begomovirus, which has caused enormous losses in commercial production of various horticultural crops. The goal of the present work was to characterize ex situ 18 genotypes of C. annuum from southern Mexico through 47 morphological descriptors, and to evaluate...

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

    OpenAIRE

    2014-01-01

    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...

  19. Estimation of the Whitefly Bemisia tabaci Genome Size Based on k-mer and Flow Cytometric Analyses

    OpenAIRE

    Wenbo Chen; Hasegawa, Daniel K.; Kathiravetpillai Arumuganathan; Simmons, Alvin M.; Wintermantel, William M.; Zhangjun Fei; Kai-Shu Ling

    2015-01-01

    Whiteflies of the Bemisia tabaci (Hemiptera: Aleyrodidae) cryptic species complex are among the most important agricultural insect pests in the world. These phloem-feeding insects can colonize over 1000 species of plants worldwide and inflict severe economic losses to crops, mainly through the transmission of pathogenic viruses. Surprisingly, there is very little genomic information about whiteflies. As a starting point to genome sequencing, we report a new estimation of the genome size of ...

  20. Heritability and Evolutionary Potential in Thermal Tolerance Traits in the Invasive Mediterranean Cryptic Species of Bemisia tabaci (Hemiptera: Aleyrodidae)

    OpenAIRE

    Ma, Fang-Zhou; Lü, Zhi-Chuang; Wang, Ren; Wan, Fang-Hao

    2014-01-01

    With advancing global climate change, the analysis of thermal tolerance and evolutionary potential is important in explaining the ecological adaptation and changes in the distribution of invasive species. To reveal the variation of heat resistance and evolutionary potential in the invasive Mediterranean cryptic species of Bemisia tabaci, we selected two Chinese populations—one from Harbin, N China, and one from Turpan, S China—that experience substantial heat and cold stress and conducted kno...

  1. [Effects of calcium fertilizer on the development, survival, and feeding of B-biotype Bemisia tabaci on Euphorbia pulcherrima].

    Science.gov (United States)

    Huang, Jun; Zhang, Juan; Yu, Yong-Ming; Liu, Jian-Xin; Li, Ming-Jiang; Zhu, Kai-Yuan

    2012-09-01

    This paper studied the development, survival, and feeding of B-biotype Bemisia tabaci on Euphorbia pulcherrima under the conditions of 26 +/- 1 degrees C and 60% - 80% relative humidity after applying calcium fertilizer, taking applying fresh water as the control. There existed significant differences in the developmental duration of B. tabaci between treatment applying calcium fertilizer and the control. After applying calcium fertilizer, the egg stage of B. tabaci shortened significantly, and the development from egg to adult took 20.18 days (for the control, it took 18.72 days). However, there were no significant differences in the survival rates of B. tabaci at different development stages between the two treatments. The feeding of B. tabaci on E. pulcherrima induced the plant leaf chlorophyll fluorescence parameters changed, i. e., the photochemical efficiency (Fv/Fm), photochemical quenching coefficient (q(p)), light use efficiency (alpha), maximum photosynthesis rate (rETRmax), and tolerance to light (I(k)) decreased significantly, while the non-photochemical quenching coefficient (NPQ) had a significant increase. After applying calcium fertilizer, the plant leaf photoinhibition parameter (beta), rETRmax, and I(k) had less difference with th e control. The nail polish blot observation on the lower epidermis structure of plant leaf showed that calcium fertilizer could effectively compensate the decrease in the photosynthesis of E. pulcherrima damaged by B-biotype B. tabaci. PMID:23286011

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

    Directory of Open Access Journals (Sweden)

    Horacio Ballina-Gomez

    2013-12-01

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

  3. 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)

  4. Bean yellow disorder virus: Parameters of transmission by Bemisia tabaci and host plant range

    Institute of Scientific and Technical Information of China (English)

    German Martín; Isabel Maria Cuadrado; Dirk Janssen

    2011-01-01

    Bean yellow disorder virus(BnYDV)was recently identified as the first crinivirus(family Closteroviridae)that infects members of the family Leguminosae.It was first observed during the autumn of 2003,causing heavy losses in French bean (Phaseolus vulgaris L.)grown commercially in Spain.The virus is transmitted by the sweetpotato whitefly,Bemisia tabaci(Hemiptera:Aleyrodidae)Q-biotype,and disease symptoms resemble nutritional disorders consisting of interveinal mottling and yellowing in leaves,combined with stiffness or brittleness,and are typically produced on the middle to lower parts of the plant.Transmission experiments showed that 50% and 100% of B.tabaci adults acquired the virus after a feeding period of 3 and 7 h,respectively.Viruliferous whiteflies infected 66% and 100% of P.vulgaris plants after a feeding period of 12 and 24 h,respectively.The transmission efficiency of single whiteflies was 37% and persistence of BnYDV in the vector lasted up to 2 weeks with a half-life of 9 days.BnYDV was transmitted to P.vulgaris,Pisum sativum L.,Lens culinaris Medik.,and Vicia faba L.,but not to Vigna unguiculata L.,Glycine max(L.) Merr.,Cicer arietum L.,and to crop species belonging to families of the Solanaceae and Cucurbitaceae.No virus was detected in field samples collected from 30 different species from Boraginaceae,Asteraceae,Geraniaceae,Lamiaceae,Leguminosae,Malvaceae,Scrophulariaceae,Thymelaeaceae and Verbenaceae.The restricted host range and efficient management of crops regarding whitefly infestation may be key elements in the control of BnYDV.

  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. PMID:27247302

  6. 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

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

    Indian Academy of Sciences (India)

    Santosh Kumar Upadhyay; K Chandrashekar; Nidhi Thakur; Praveen Chandra Verma; J Francis Borgio; Pradhyumna Kumar; Rakesh Tuli

    2011-03-01

    RNA interference (RNAi)-mediated gene silencing was explored for the control of sap-sucking pest Bemisia tabaci, commonly known as whitefly. dsRNAs and siRNAs were synthesized from five different genes – actin ortholog, ADP/ATP translocase, -tubulin, ribosomal protein L9 (RPL9) and V-ATPase A subunit. A simplified insect bioassay method was developed for the delivery of ds/siRNA through the oral route, and efficacy was evaluated. ds/siRNA caused 29–97% mortality after 6 days of feeding. Each insect ingested nearly 150 nl of insect diet per day, which contained a maximum of 6 ng of RNA. Knocking down the expression of RPL9 and V-ATPase A caused higher mortality with LC50 11.21 and 3.08 g/ml, respectively, as compared to other genes. Semi-quantitative PCR of the treated insects showed significant decrease in the level of RPL9 and V-ATPase A transcripts. siRNAs were found stable in the insect diet for at least 7 days at the room temperature. Phloem-specific expression of dsRNAs of RPL9 and V-ATPase A in transgenic plants for the protection against whiteflies might be an interesting application of this technology.

  8. Evidence for horizontal transmission of secondary endosymbionts in the Bemisia tabaci cryptic species complex.

    Directory of Open Access Journals (Sweden)

    Muhammad Z Ahmed

    Full Text Available Bemisia tabaci (Hemiptera: Aleyrodidae is a globally distributed pest composed of at least 34 morphologically indistinguishable cryptic species. At least seven species of endosymbiont have been found infecting some or all members of the complex. The origin(s of the associations between specific endosymbionts and their whitefly hosts is unknown. Infection is normally vertical, but horizontal transmission does occur and is one way for new infections to be introduced into individuals. The relationships between the different members of the cryptic species complex and the endosymbionts have not been well explored. In this study, the phylogenies of different cryptic species of the host with those of their endosymbionts were compared. Of particular interest was whether there was evidence for both coevolution and horizontal transmission. Congruence was observed for the primary endosymbiont, Portiera aleyrodidarum, and partial incongruence in the case of two secondary endosymbionts, Arsenophonus and Cardinium and incongruence for a third, Wolbachia. The patterns observed for the primary endosymbiont supported cospeciation with the host while the patterns for the secondary endosymbionts, and especially Wolbachia showed evidence of host shifts and extinctions through horizontal transmission rather than cospeciation. Of particular note is the observation of several very recent host shift events in China between exotic invader and indigenous members of the complex. These shifts were from indigenous members of the complex to the invader as well as from the invader to indigenous relatives.

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

    International Nuclear Information System (INIS)

    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)

  10. Computational Insights into the Different Resistance Mechanism of Imidacloprid versus Dinotefuran in Bemisia tabaci.

    Science.gov (United States)

    Meng, Xiaoqing; Zhu, Chengchun; Feng, Yue; Li, Weihua; Shao, Xusheng; Xu, Zhiping; Cheng, Jiagao; Li, Zhong

    2016-02-17

    Insecticide resistance is a critical problem for pest control and management. For Bemisia tabaci, striking high metabolic resistance (generally conferred by CYP6CM1) was observed for imidacloprid (IMI) and most other neonicotinoid members. However, dinotefuran (DIN) displayed very low resistance factors, which indicated distinct metabolic properties. Here, molecular modeling methods were applied to explore the different resistance features of IMI versus DIN within the Q type of CYP6CM1. It was found that Arg225 played crucial roles in the binding of IMI-CYP6CM1vQ with a cation-π interaction and two stable H-bonds; however, such interactions were all absent in the DIN-CYP6CM1vQ system. The stable binding of IMI with CYP6CM1vQ would facilitate the following metabolic reaction, while the weak binding of DIN might disable its potential metabolism, which should be an important factor for their distinct resistance levels. The findings might facilitate future design of the antiresistance neonicotinoid molecules. PMID:26817991

  11. Resistencia genética al Virus del Arrugamiento Foliar del Fríjol transmitido por Bemisia tabaci (Hemiptera: Aleyrodidae) Genetic resistance to Bean Leaf Crumple Virus transmitted by Bemisia tabaci (Hemiptera: Aleyrodidae)

    OpenAIRE

    MARÍA ELENA CUÉLLAR J.; Morales, Francisco J.; JAMES MONTOYA LERMA

    2011-01-01

    Desde 2002, los cultivos de fríjol habichuela (Phaseolus vulgaris) de la parte plana del Valle del Cauca han sido afectados por el Virus del Arrugamiento Foliar del Fríjol (Begomovirus: Geminiviridae) agente causal de una nueva y severa enfermedad, transmitido por el biotipo B de la mosca blanca, Bemisia tabaci. Se investigó la relación virus-vector utilizando genotipos de fríjol común seleccionados como posibles fuentes de resistencia. Se determinó la eficiencia de transmisión del virus usan...

  12. Evaluación de ácido acético como fumigante de mosquita blanca Bemisia tabaci (Gennadious) en laboratorio y campo Assessment of acetic acid like fumigant of silverleaf whitefly Bemisia tabaci (Gennadious) in laboratory and field

    OpenAIRE

    José Alfredo Samaniego Gaxiola; José Emmanuel Amaya Carrillo; José Luis Puente Manríquez

    2012-01-01

    El objetivo de este trabajo fue evaluar la capacidad del ácido acético (AA) como fumigante en contra de Bemisia tabaci (moquita blanca) que es un plaga de importancia nacional. En el laboratorio, se fumigó el insecto con tres regímenes de dosis - tiempo: (ambos medios), baja - largos y altas - cortos. En el campo, las hojas de calabaza de cuatro variedades fueron fumigadas con 8, 16 y 32 µg ml-1 de AA en tiempos de 20, 40 y 60 min; adicionalmente, se evaluó el daño en las hojas (fitotoxicidad...

  13. 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

    OpenAIRE

    Patricia Valle Pinheiro; Eliane Dias Quintela; Jaison Pereira de Oliveira; José Carlos Seraphin

    2009-01-01

    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 ...

  14. 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. PMID:26958907

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Flow cytometry and K-mer analysis estimates of the genome sizes of Bemisia tabaci B and Q (Hemiptera: Aleyrodidae)

    OpenAIRE

    Guo, Li T.; Wang, Shao L.; Wu, Qing J.; Zhou, Xu G.; Xie, Wen; Zhang, You J.

    2015-01-01

    The genome sizes of the B- and Q-types of the whitefly Bemisia tabaci (Gennnadius) were estimated using flow cytometry (Drosophila melanogaster as the DNA reference standard and propidium iodide (PI) as the fluorochrome) and k-mer analysis. For flow cytometry, the mean nuclear DNA content was 0.686 pg for B-type males, 1.392 pg for B-type females, 0.680 pg for Q-type males, and 1.306 pg for Q-type females. Based on the relationship between DNA content and genome size (1 pg DNA = 980 Mbp), the...

  17. Resistência de genótipos de feijoeiro a Bemisia tabaci biótipo B

    OpenAIRE

    Lucas Castro Torres; Brígida Souza; André Luiz Lourenção; Marlice Botelho Costa; Bruno Barbosa Amaral; Sérgio Augusto Morais Carbonell; Alisson Fernando Chiorato; Ricardo Lima Tanque

    2012-01-01

    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...

  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. Estimation of the Whitefly Bemisia tabaci Genome Size Based on k-mer and Flow Cytometric Analyses.

    Science.gov (United States)

    Chen, Wenbo; Hasegawa, Daniel K; Arumuganathan, Kathiravetpillai; Simmons, Alvin M; Wintermantel, William M; Fei, Zhangjun; Ling, Kai-Shu

    2015-01-01

    Whiteflies of the Bemisia tabaci (Hemiptera: Aleyrodidae) cryptic species complex are among the most important agricultural insect pests in the world. These phloem-feeding insects can colonize over 1000 species of plants worldwide and inflict severe economic losses to crops, mainly through the transmission of pathogenic viruses. Surprisingly, there is very little genomic information about whiteflies. As a starting point to genome sequencing, we report a new estimation of the genome size of the B. tabaci B biotype or Middle East-Asia Minor 1 (MEAM1) population. Using an isogenic whitefly colony with over 6500 haploid male individuals for genomic DNA, three paired-end genomic libraries with insert sizes of ~300 bp, 500 bp and 1 Kb were constructed and sequenced on an Illumina HiSeq 2500 system. A total of ~50 billion base pairs of sequences were obtained from each library. K-mer analysis using these sequences revealed that the genome size of the whitefly was ~682.3 Mb. In addition, the flow cytometric analysis estimated the haploid genome size of the whitefly to be ~690 Mb. Considering the congruency between both estimation methods, we predict the haploid genome size of B. tabaci MEAM1 to be ~680-690 Mb. Our data provide a baseline for ongoing efforts to assemble and annotate the B. tabaci genome. PMID:26463411

  20. 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

  1. Rapid accumulation and low degradation: key parameters of Tomato yellow leaf curl virus persistence in its insect vector Bemisia tabaci.

    Science.gov (United States)

    Becker, Nathalie; Rimbaud, Loup; Chiroleu, Frédéric; Reynaud, Bernard; Thébaud, Gaël; Lett, Jean-Michel

    2015-01-01

    Of worldwide economic importance, Tomato yellow leaf curl virus (TYLCV, Begomovirus) is responsible for one of the most devastating plant diseases in warm and temperate regions. The DNA begomoviruses (Geminiviridae) are transmitted by the whitefly species complex Bemisia tabaci. Although geminiviruses have long been described as circulative non-propagative viruses, observations such as long persistence of TYLCV in B. tabaci raised the question of their possible replication in the vector. We monitored two major TYLCV strains, Mild (Mld) and Israel (IL), in the invasive B. tabaci Middle East-Asia Minor 1 cryptic species, during and after the viral acquisition, within two timeframes (0-144 hours or 0-20 days). TYLCV DNA was quantified using real-time PCR, and the complementary DNA strand of TYLCV involved in viral replication was specifically quantified using anchored real-time PCR. The DNA of both TYLCV strains accumulated exponentially during acquisition but remained stable after viral acquisition had stopped. Neither replication nor vertical transmission were observed. In conclusion, our quantification of the viral loads and complementary strands of both Mld and IL strains of TYLCV in B. tabaci point to an efficient accumulation and preservation mechanism, rather than to a dynamic equilibrium between replication and degradation. PMID:26625871

  2. Molecular cloning of the sex-related gene PSI in Bemisia tabaci and its alternative splicing properties.

    Science.gov (United States)

    Liu, Yating; Xie, Wen; Yang, Xin; Guo, Litao; Wang, Shaoli; Wu, Qingjun; Yang, Zezhong; Zhou, Xuguo; Zhang, Youjun

    2016-04-15

    The P-element somatic inhibitor (PSI) is gene known to regulate the transcription of doublesex (dsx) when transformer (tra) is absent in Bombyx mori. In this study, we identified and characterized a PSI homolog in Bemisia tabaci (BtPSI). BtPSI cDNA had a total length of 5700bp and contained a predicted open reading frame (ORF) of 2208 nucleotides encoding for 735 amino acids. Multiple sequence alignments of the common regions of PSI proteins from B. tabaci and five other insect species revealed a high degree of sequence conservation. BtPSI is expressed in all stages of B. tabaci development, and expression did not significantly differ between female and male adult. A total of 92 BtPSI isoforms (78 in female and 22 in male) were identified, and a marker indicating the female-specific form was found. These results increase the understanding of genes that may determine sex in B. tabaci and provide a foundation for research on the sex determination mechanism in this insect. PMID:26773355

  3. Estimation of the Whitefly Bemisia tabaci Genome Size Based on k-mer and Flow Cytometric Analyses

    Directory of Open Access Journals (Sweden)

    Wenbo Chen

    2015-07-01

    Full Text Available Whiteflies of the Bemisia tabaci (Hemiptera: Aleyrodidae cryptic species complex are among the most important agricultural insect pests in the world. These phloem-feeding insects can colonize over 1000 species of plants worldwide and inflict severe economic losses to crops, mainly through the transmission of pathogenic viruses. Surprisingly, there is very little genomic information about whiteflies. As a starting point to genome sequencing, we report a new estimation of the genome size of the B. tabaci B biotype or Middle East-Asia Minor 1 (MEAM1 population. Using an isogenic whitefly colony with over 6500 haploid male individuals for genomic DNA, three paired-end genomic libraries with insert sizes of ~300 bp, 500 bp and 1 Kb were constructed and sequenced on an Illumina HiSeq 2500 system. A total of ~50 billion base pairs of sequences were obtained from each library. K-mer analysis using these sequences revealed that the genome size of the whitefly was ~682.3 Mb. In addition, the flow cytometric analysis estimated the haploid genome size of the whitefly to be ~690 Mb. Considering the congruency between both estimation methods, we predict the haploid genome size of B. tabaci MEAM1 to be ~680–690 Mb. Our data provide a baseline for ongoing efforts to assemble and annotate the B. tabaci genome.

  4. 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 ...

  5. Comparison of the Genome Sequences of “Candidatus Portiera aleyrodidarum” Primary Endosymbionts of the Whitefly Bemisia tabaci B and Q Biotypes

    OpenAIRE

    Jiang, Zi-Feng; Xia, Fangfang; Johnson, Kipp W.; Brown, Christopher D.; Bartom, Elizabeth; Tuteja, Jigyasa H.; Stevens, Rick; Grossman, Robert L; Brumin, Marina; White, Kevin P.; Ghanim,Murad

    2013-01-01

    “Candidatus Portiera aleyrodidarum” is the primary endosymbiont of whiteflies. We report two complete genome sequences of this bacterium from the worldwide invasive B and Q biotypes of the whitefly Bemisia tabaci. Differences in the two genome sequences may add insights into the complex differences in the biology of both biotypes.

  6. Complete Genome Sequence of “Candidatus Portiera aleyrodidarum” BT-QVLC, an Obligate Symbiont That Supplies Amino Acids and Carotenoids to Bemisia tabaci

    OpenAIRE

    Santos-Garcia, Diego; Farnier, Pierre-Antoine; Beitia, Francisco; Zchori-Fein, Einat; Vavre, Fabrice; Mouton, Laurence; Moya, Andrés; Latorre, Amparo; Silva, Francisco J.

    2012-01-01

    The genome of “Candidatus Portiera aleyrodidarum,” the primary endosymbiont of the whitefly Bemisia tabaci (Mediterranean species), is reported. It presents a reduced genome (357 kb) encoding the capability to synthetize, or participate in the synthesis of, several amino acids and carotenoids, being the first insect endosymbiont capable of supplying carotenoids.

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

    International Nuclear Information System (INIS)

    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)

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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

  10. 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

  11. 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.

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

    Science.gov (United States)

    Liu, Guoxia; Ma, Hongmei; Xie, Hongyan; Xuan, Ning; Guo, Xia; Fan, Zhongxue; Rajashekar, Balaji; Arnaud, Philippe; Offmann, Bernard; Picimbon, Jean-François

    2016-01-01

    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. PMID:27167733

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

    Science.gov (United States)

    Liu, Guoxia; Ma, Hongmei; Xie, Hongyan; Xuan, Ning; Guo, Xia; Fan, Zhongxue; Rajashekar, Balaji; Arnaud, Philippe; Offmann, Bernard; Picimbon, Jean-François

    2016-01-01

    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. PMID:27167733

  14. Scientific Opinion on the risks to plant health posed by Bemisia tabaci species complex and viruses it transmits for the EU territory

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Plant Health (PLH

    2013-04-01

    Full Text Available The Panel on Plant Health conducted a pest risk assessment for Bemisia tabaci and the viruses it transmits, including an evaluation of risk reduction options and an assessment of the effectiveness of the special requirements linked to B. tabaci and the viruses listed in Council Directive 2000/29/EC. B. tabaci and a large number of viruses transmitted by this polyphagous insect occur in subtropical and tropical climates around the world. Five entry pathways for B. tabaci and associated viruses were identified, with the plants for planting pathway being most significant and rated for entry of insects and viruses as likely and moderately likely, respectively. The most invasive B. tabaci species and several of its associated viruses responsible for severe diseases in major European food crops are established outdoors in coastal Mediterranean regions. Because of similar climate requirements and host plant preferences, B. tabaci and associated viruses currently not present in Europe are likely to establish within the temperature limits set for B. tabaci. Trade between European Member States allows B. tabaci to reach greenhouses in northern Europe, including those in areas with protected zone status. Because of the cool climate, establishment and spread outdoors of B. tabaci is rated unlikely for northern Europe. This situation is likely to continue even under a climatic scenario with an increase in temperature of +2 °C. B. tabaci -transmitted viruses cause severe diseases with major negative impact on crop production when risk reduction measures are not used. Risk reduction options will also apply to B. tabaci and viruses new to Europe. Risk reductions options are evaluated in terms of reducing B. tabaci populations, crop infestations, virus incidence and the impact of diseases. © European Food Safety Authority, 2013

  15. The presence of six cryptic species of the whitefly Bemisia tabaci complex in China as revealed by crossing experiments

    Institute of Scientific and Technical Information of China (English)

    Peng Wang; Di-Bing Sun; Bao-Li Qiu; Shu-Sheng Liu

    2011-01-01

    Recent phylogenetic analysis using mitochondrial cytochrome oxidase I(mtCOI)sequences of Bemisia tabaci worldwide indicates that the whitefly comprises at least 24 morphologically indistinguishable but genetically distinct cryptic species.While evidence of reproductive isolation has been reported for some of the putative species,more extensive crossing experiments are required to clarify the systematics of this species complex.In this study,we established laboratory cultures for six putative species of B.tabaci collected in China.We conducted 22 inter-species crosses among the six putative species.The data and those reported previously were collated,and the combined dataset covered all the 30 possible inter-species crosses among the six putative species.Intra-species controls always produced female and male progeny and the proportions of females in the first generation(F1)ranged from 56% to 70%.However,in inter-species crosses female progeny were rarely produced,and the few F1 females produced in four of the 30 inter-species crosses were either sterile or significantly weaker in viability.These results demonstrate a pattern of complete reproductive isolation among the six putative species and show that they are six cryptic species in the B.tabaci complex.

  16. Pathogenicity of Isaria fumosorosea to Bemisia tabaci, with some observations on the fungal infection process and host immune response.

    Science.gov (United States)

    Tian, Jing; Diao, Hongliang; Liang, Li; Hao, Chi; Arthurs, Steven; Ma, Ruiyan

    2015-09-01

    Isaria fumosorosea is an important pathogen of whiteflies, and is used as a mycoinsecticide against this pest in many regions of the world. We quantified the pathogenicity of the Chinese isolate IF-1106 against different life stages of sweetpotato whitefly, Bemisia tabaci, on cucumber plants, and describe the infection process and aspects of the host immunological response in the laboratory. The second instar was the most susceptible life stage to infection, with mortality rates at 10(7)conidia/ml ≈83% after 7d. Scanning electron microscopy was used to monitor morphological aspects of the infection process. The following stages were observed; conidia adhered on the cuticle of B. tabaci and began to germinate within 6h of inoculation, appressoria development after 24h, germ tube penetration within 48h, emergent hyphae within 72h, secondary conidiogenesis within 96h with mass hyphal proliferation occurring on cadavers within 120h. The activities of endogenous enzymes were evaluated from host homogenate at various intervals post infection. Three enzymes associated with antioxidant activity [superoxide dismutase (SOD), perioxidase (POD), and catalase (CAT)], and two with detoxification [glutathione S-transferase (GSTs) and carboxylesterase (CarE)] were apparently upregulated in second instars infected by I. fumosorosea. Enzyme activities reached peak values at 48-60h post infection, then decreased to significantly lower than controls in 84h as mycosis occurred. Our results provide new insights into the pathogenicity and potential physiological response of B. tabaci to this fungal isolate. PMID:26264671

  17. Differential expression patterns among heat-shock protein genes and thermal responses in the whitefly Bemisia tabaci (MEAM 1).

    Science.gov (United States)

    Díaz, Fernando; Orobio, Rony F; Chavarriaga, Paul; Toro-Perea, Nelson

    2015-08-01

    There is convincing evidence that heat-shock proteins (HSP) are upregulated by stress conditions in insects; however, the relative contribution of each HSP gene to the heat-shock response remains unclear. Here we considered the whitefly Bemisia tabaci (MEAM 1), a phloem feeder and invasive species whose molecular stress response is an important mechanism for overcoming heat stress. We assessed the expression of the hsp23, 40, 70 and 90 genes at the mRNA level when submitted to heat shocks of 40 and 44°C/1h (control at 25°C). For this, we evaluated a set of available and suitable reference genes in order to perform data normalization using the real-time polymerase chain reaction (qRT-PCR) technique, and then confirmed the production of HSP70 protein based on Western blot. Results were compared with the hardening capacity of B. tabaci, measured by fitness components as a response to heat shocks, using 40°C as the induction temperature. Three of the four genes (hsp23, 70 and 90) were upregulated by heat stress at mRNA, showing differential expression patterns. Hsp70 expression was confirmed at the protein level. Hardening significantly increased fitness following heat stress, suggesting that HSPs may contribute to hardening capacity in B. tabaci. Potential role of each gene in the heat-shock response for whiteflies is discussed. PMID:26267515

  18. 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

    2015-01-01

    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. PMID:26655836

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

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    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.

  20. Caractérisation des populations de Bemisia tabaci en fonction des plantes hôtes : recherche de marqueurs électrophorétiques et transferts d'hôtes

    OpenAIRE

    Burban, C.; Fishpool, Lincoln D. C.; Abisgold, J D

    1989-01-01

    The whitefly #Bemisia tabaci$ is a well known vector of African Cassava Mosaic in tropical countries. By using isozyme electrophoresis (esterase patterns) and host-range studies, tow types of #B. tabaci$ were characterised : one breeding mainly on cassava, the other breeding on all plants other than cassava. Each types shows a different esterase pattern. (Résumé d'auteur)

  1. Activation of the Phenylpropanoid pathway in Nicotiana tabacum improves the performance of the whitefly Bemisia tabaci via reduced jasmonate signaling.

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    Michal Alon

    Full Text Available BACKGROUND: Phloem-feeding insects can manipulate plant-induced resistance and are able to suppress effective jasmonic acid/ethylene (JA/ET defenses by the induction of inefficient salicylic acid (SA based responses. As a result, activation of the phenylpropanoid biosynthesis pathway in transgenic plants is anticipated to cause complex interactions between phloem-feeding insects and their host plants due to predicted contradiction between two defense forces: the toxicity of various phenylpropanoids and the accumulation of SA via a branch of the activated pathway. METHODOLOGY/PRINCIPAL FINDINGS: Here, we investigated the effect of activating the phenylpropanoids pathway in Nicotiana tabacum, by over-expression of the PAP1 transcription factor, on the whitefly Bemisia tabaci, a phloem-feeding insect model. Our performance assays indicated that the over-expression made the transgenic plants a more suitable host for B. tabaci than wild-type (WT plants, although these plants accumulated significantly higher levels of flavonoids. Transcription analyses of indicator genes in the SA (PR1a and JA/ET (ERF1, COI1 and AOC pathways followed by quantification of the SA and JA hormone levels, indicated that B. tabaci infestation periods longer than 8 hours, caused higher levels of activity of SA signaling in transgenic plants and higher levels of JA/ET signaling in WT plants. CONCLUSIONS/SIGNIFICANCE: Taken together, these results emphasize the important role JA/ET-induced defenses play in protecting plants from successful infestation by B. tabaci and likely other phloem-feeding insects. It also indicates the necessity of phloem feeders to suppress these defenses for efficient utilization of plant hosts. Our data also indicate that the defensive chemistry produced by the phenylpropanoids pathway has only a minor effect on the insect fitness.

  2. Chitinolytic Bacteria Isolated from Chili Rhizosphere: Chitinase Characterization and Its Application as Biocontrol for Whitefly (Bemisia tabaci Genn.

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    Nisa R. Mubarik

    2010-01-01

    Full Text Available Problem statement: Chitin, a common constituent of insect exoskeleton, could be hydrolyzed by chitinase. The research was conducted to screen chitinolytic rhizobacteria isolated from rhizosphere of chilli pepper and to determine their chitinase activity in degrading chitin of whitefly, Bemisia tabaci Genn. (Hemiptera: Aleyrodidae. Whitefly is recognized as an important pest on many crops including chilli pepper. Approach: Screening and molecular identification based on 16S rRNA sequence of chitinolytic isolates, chitinase productions, measurement of chitinase activity, characterization of chitinase and effect of the chitinase treatment on whitefly were studied. Results: A total of 25 isolates of rhizobacteria formed a clear zone on solid chitin media. Two isolates, i.e., I.5 and I.21 isolates had the highest chitinolytic index. Based on sequence of 16S rRNA gene, the isolates of I.5 and I.21 were identified as Bacillus sp. and Bacillus cereus, respectively. The highest chitinolytic index and specific activity of I.5 isolate was 0.94 and 0.11 U mg-1 proteins, respectively. Maximum production of I.5 chitinase was occured after 36 h cultivation at 30°C and pH 7.0. The highest chitinolytic index and specific activity of I.21isolate was 0.75 and 0.114 U mg-1 proteins, respectively. Maximum production of I.21 chitinase was occured after 36 h cultivation at 55°C and pH 7.0. Cell culture and crude enzyme of the isolates were tested on chitin of B. tabaci and the effect was observed using a microscope and sterile water was used as a negative control. Hydrolytic observation showed that crude enzyme of I.21 isolate could degrade chitin of B. tabaci exoskeleton and the activity was better than that of I.5 isolate. Conclusion: Chitinase produced by Bacillus cereus I.21 strain has potential application as biocontrol agents for B. tabaci.

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

    OpenAIRE

    Luciana Cláudia Toscano; Terezinha Monteiro dos Santos; Arlindo Leal Boiça Júnior

    2003-01-01

    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 De...

  4. Elimination of Arsenophonus and decrease in the bacterial symbionts diversity by antibiotic treatment leads to increase in fitness of whitefly, Bemisia tabaci.

    Science.gov (United States)

    Raina, Harpreet Singh; Rawal, Vagisha; Singh, Shama; Daimei, Guisuibou; Shakarad, Mallikarjun; Rajagopal, Raman

    2015-06-01

    Bemisia tabaci is an invasive agricultural pest with more than 24 genetic groups harboring different bacterial endosymbionts categorized into obligatory and facultative endosymbionts. Arsenophonus is one of the facultative endosymbionts prevalent in B. tabaci of Indian sub-continent. Not much is known about the functional role of this endosymbiont in its host. Some studies have revealed its involvement in virus transmission by B. tabaci, but how it effects the biology of B. tabaci is unknown. In this study, tetracycline was used to eliminate Arsenophonus from B. tabaci to study its effects with regard to development and other fitness parameters. Bacteria specific 16S Polymerase chain reaction (PCR) was used to ascertain Arsenophonus absence with differential effects on other secondary endosymbionts present in B. tabaci. Our results revealed that Arsenophonus negative (A(-)) whiteflies had more fecundity, increased juvenile developmental time, increased nymphal survival and increased adult life span as compared to control (A(+)) whiteflies. Thus, our results demonstrate that A(+) whiteflies have lesser fitness as compared to A(-) whiteflies. These observations give a new insight about the probable role of Arsenophonus in B. tabaci, that need to be explored further. PMID:25801610

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

    Science.gov (United States)

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

    2015-10-01

    Plant defense to pests or pathogens involves global changes in gene expression mediated by multiple signaling pathways. A role for the salicylic acid (SA) signaling pathway in Mi-1-mediated resistance of tomato (Solanum lycopersicum) to aphids was previously identified and its implication in the resistance to root-knot nematodes is controversial, but the importance of SA in basal and Mi-1-mediated resistance of tomato to whitefly Bemisia tabaci had not been determined. SA levels were measured before and after B. tabaci infestation in susceptible and resistant Mi-1-containing tomatoes, and in plants with the NahG bacterial transgene. Tomato plants of the same genotypes were also screened with B. tabaci (MEAM1 and MED species, before known as B and Q biotypes, respectively). The SA content in all tomato genotypes transiently increased after infestation with B. tabaci albeit at variable levels. Whitefly fecundity or infestation rates on susceptible Moneymaker were not significantly affected by the expression of NahG gene, but the Mi-1-mediated resistance to B. tabaci was lost in VFN NahG plants. Results indicated that whiteflies induce both SA and jasmonic acid accumulation in tomato. However, SA has no role in basal defense of tomato against B. tabaci. In contrast, SA is an important component of the Mi-1-mediated resistance to B. tabaci in tomato. PMID:26032615

  6. Aqueous extracts of some medicinal plants are as toxic as Imidacloprid to the sweet potato whitefly, Bemisia tabaci.

    Science.gov (United States)

    Ateyyat, Mazen A; Al-Mazra'awi, Mohammad; Abu-Rjai, Talal; Shatnawi, Mohamad A

    2009-01-01

    Aqueous extracts of nine plants, known to have medicinal activity, were tested for their toxicity against the sweet potato whitefly, Bemisia tabaci Genn. (Homoptera: Aleurodidae) compared to the toxicity of the insecticide, Imidacloprid. Extracts of Lepidiuim sativum L. (Brassicales: Brassicaceae) killed 71 % of early stage nymphs, which was not significantly different from mortality caused by Imidacloprid. Treatment of pupae with three plant extracts, L. sativum, Achillea biebersteinii L. (Asterales: Asteraceae), or Retama raetam (Forssk.) Webb and Berthel (Fabales: Fabaceae) prevented adult development, and treatment with R. raetam extract killed adults, at levels that were not significantly different from Imidacloprid. None of the other plants showed significant toxicity. However extracts of four plants, Pimpinella anisum L. (Apiales: Apiaceae), Galium longifolium (Sibth. and SM.) (Gentianales: Rubiaceae), R. raetam and Ballota undulata Bentham (Lamiales: Lamiaceae) had a repellent effect. PMID:19613450

  7. 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)

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

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    Giuliana Etore do Valle

    2002-06-01

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

  10. Transmission of Tomato Yellow Leaf Curl Virus by Bemisia tabaci as Affected by Whitefly Sex and Biotype.

    Science.gov (United States)

    Ning, Wenxi; Shi, Xiaobin; Liu, Baiming; Pan, Huipeng; Wei, Wanting; Zeng, Yang; Sun, Xinpei; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Cheng, Jiaxu; Peng, Zhengke; Zhang, Youjun

    2015-01-01

    Bemisia tabaci is a serious pest of vegetables and other crops worldwide. The most damaging and predominant B. tabaci biotypes are B and Q, and both are vectors of tomato yellow leaf curl virus (TYLCV). Previous research has shown that Q outperforms B in many respects but comparative research is lacking on the ability of B and Q to transmit viruses. In the present study, we tested the hypothesis that B and Q differ in their ability to transmit TYLCV and that this difference helps explain TYLCV outbreaks. We compared the acquisition, retention, and transmission of TYLCV by B and Q females and males. We found that Q females are more efficient than Q males, B females, and B males at TYLCV acquisition and transmission. Although TYLCV acquisition and transmission tended to be greater for B females than B males, the differences were not statistically significant. Based on electrical penetration graphs determination of phloem sap ingestion parameters, females fed better than males, and Q females fed better than Q males, B females, or B males. These results are consistent with the occurrences of TYLCV outbreaks in China, which have been associated with the spread of Q rather than B. PMID:26021483

  11. Host-Associated Population Variations of Bemisia tabaci (Genn.) (Hemiptera:Sternorrhyncha: Aleyrodidae) Characterized with Random DNA Markers

    OpenAIRE

    Helmi, A.

    2011-01-01

    Whitefly, Bemisia tabaci (Genn.) is an important sucking plant sap pest of field, horticultural and ornamental plants causing feeding injuries besides spreading plant diseases by acting as a vector of Gemini-viruses. The polyphagous nature of the pest makes it as a highly complex species. The influence of six host plants belonging to three different plant families utilized by the species on the population differences at molecular level was attempted using Random Amplified Polymorphic DNA (RAP...

  12. Chitinolytic Bacteria Isolated from Chili Rhizosphere: Chitinase Characterization and Its Application as Biocontrol for Whitefly (Bemisia tabaci Genn.)

    OpenAIRE

    NISA R MUBARIK; Irni Mahagiani; Amaryllis Anindyaputri; Sugeng Santoso; Iman Rusmana

    2010-01-01

    Problem statement: Chitin, a common constituent of insect exoskeleton, could be hydrolyzed by chitinase. The research was conducted to screen chitinolytic rhizobacteria isolated from rhizosphere of chilli pepper and to determine their chitinase activity in degrading chitin of whitefly, Bemisia tabaci Genn. (Hemiptera: Aleyrodidae). Whitefly is recognized as an important pest on many crops including chilli pepper. Approach: Screening and molecular identification based on 16...

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

    OpenAIRE

    Fatemeh Jafarbeigi; Mohammad Amin Samih; Mehdi Zarabi; Saeideh Esmaeily

    2014-01-01

    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 neem...

  14. The genome of Cardinium cBtQ1 provides insights into genome reduction, symbiont motility, and its settlement in Bemisia tabaci.

    OpenAIRE

    Santos-Garcia, Diego; Rollat-Farnier, Pierre-Antoine; Beitia, Francisco; Zchori-Fein, Einat; Vavre, Fabrice; Mouton, Laurence; Moya, Andrés; Latorre, Amparo; Silva, Francisco J.

    2014-01-01

    Many insects harbor inherited bacterial endosymbionts. Although some of them are not strictly essential and are considered facultative, they can be a key to host survival under specific environmental conditions, such as parasitoid attacks, climate changes, or insecticide pressures. The whitefly Bemisia tabaci is at the top of the list of organisms inflicting agricultural damage and outbreaks, and changes in its distribution may be associated to global warming. In this work, we have sequenced ...

  15. Identification and characterization of two phospholipid hydroperoxide glutathione peroxidase genes from the Mediterranean species of the whitefly Bemisia tabaci complex.

    Science.gov (United States)

    Jiu, Min; Li, Jun-Min; Gao, Xian-Long; Wang, Lun-Ji; Wang, Xiao-Wei; Liu, Shu-Sheng

    2015-05-01

    Phospholipid hydroperoxide glutathione peroxidases (PHGPXs) are essential enzymes of the cellular antioxidant defense system during insect-plant interactions. However, little attention has been devoted to the functional characterization of PHGXPs in the whitefly Bemisia tabaci. Here, we report the identification and characterization of two PHGPX genes, designated as BtQ-PHGPX1 and BtQ-PHGPX2 from the Mediterranean species of the B. tabaci complex. Sequence analysis indicated that the length of BtQ-PHGPX1 is of 942 bp with a 729 bp open-reading frame (ORF) encoding 242 amino acids, and BtQ-PHGPX2 is of 699 bp with a 567 bp ORF encoding 188 amino acids. Sequence alignment analysis showed that BtQ-PHGPX1 and BtQ-PHGPX2 shared high similarity with other known PHGPXs. The NVASXCGXT, FPCNQFXXQEPG, and IKWNFXKFLV surrounded the reactive cysteine, glutamine, and tryptophan residues, respectively. Recombinant BtQ-PHGPX1 and BtQ-PHGPX2 were overexpressed in Escherichia coli and purified. quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis with whiteflies of different development stages showed that the mRNA levels of BtQ-PHGPX2 were significantly higher in larvae than in other stages. The mRNA levels of BtQ-PHGPX2 were significantly higher than BtQ-PHGPX1 during all the developmental stages. The mRNA levels of BtQ-PHGPX1 and BtQ-PHGPX2 in female adults were relatively higher than in male adults. The expression of BtQ-PHGPX1 and BtQ-PHGPX2 was induced by the insecticide imidacloprid. These results suggest that BtQ-PHGPX1 and BtQ-PHGPX2 may participate in detoxification of oxidative hazards in B. tabaci. PMID:25639712

  16. Interspecific interference competition between Encarsia formosa and Encarsia sophia(Hymenoptera: Aphelinidae) in parasitizing Bemisia tabaci(Hemiptera:Aleyrodidae)on five tomato varieties

    Institute of Scientific and Technical Information of China (English)

    Shu-Ting Pang; Liang Wang; Yan-Hong Hou; Zu-Hua Shi

    2011-01-01

    Interspecific competition between Encarsia formosa and Encarsia sophia,two major parasitoids of Bemisia tabaci,and the influence of five tomato varieties on competition outcome were investigated under laboratory conditions.E.formosa parasitized more B.tabaci than E.sophia when in single wasp assays on any of the tomato varieties investigated.When B.tabaci nymphs were exposed to both wasp species(either simultaneously or sequentially),the number of B.tabaci nymphs parasitized by either waspspecies was significantly decreased compared to the sole access condition.Total mortalityof B.tabaci was increased when B.tabaci nymphs were exposed to both wasp species compared to only one wasp species.Thus competition between E.formosa and E.sophia apparently reduced parasitoid offspring numbers,but not the efficiency of biological control.In fact,control efficiency was enhanced in some cases,particularly on tomato variety Huangtuoyuan(HTY).When wasps were allowed sequential access to hosts,interference occurred through host feeding by the second wasp,especially if it was E.sophia.The effect of different tomato varieties was not significant.

  17. 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.

  18. 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

    Directory of Open Access Journals (Sweden)

    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

  19. 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

  20. Desarrollo y reproducción de Bemisia tabaci “B” (Hemiptera: Aleyrodidae sobre genotipos de yuca (Manihot esculenta Development and reproduction of Bemisia tabaci "B" (Hemiptera: Aleyrodidae on cassava (Manihot esculenta genotypes

    Directory of Open Access Journals (Sweden)

    ARTURO CARABALÍ

    2008-06-01

    Full Text Available Resumen : Los geminivirus del mosaico de la yuca (CMGs (Geminiviridae, Begomovirus y su vector la mosca blanca, Bemisia tabaci, ocasionan las mayores pérdidas en el rendimiento de raíces a cultivos de yuca en África y Asia. Evidencias recientes sugieren que B. tabaci representa un complejo de poblaciones indistinguibles morfológicamente con numerosos biotipos. En las Américas, aunque la yuca parece no ser un hospedero conveniente para el polífago biotipo B, se ha postulado que la ausencia de CMGs y daño mecánico están relacionados con la inhabilidad de este biotipo para colonizar eficientemente este cultivo. No obstante, resultados previos han demostrado que su adaptación a yuca, vía hospederos alternos, es un riesgo que debe tenerse siempre en mente. Este estudio tuvo como objetivo principal evaluar el desarrollo y la reproducción del biotipo B de B. tabaci al alimentarse sobre tres genotipos de M. esculenta (MEcu72, CG489-34 y CMC-40. A través de bioensayos bajo condiciones controladas (25 ± 2°C, 70 ± 5 HR. 12L:12O se evaluó longevidad, fecundidad, supervivencia y parámetros demográficos, mediante tablas de vida. Aunque las longevidades medias para MEcu72, CG489-34 y CMC-40 fueron similares (6,3, 5,07 y 3,9 días, respectivamente, CMC-40 presentó la tasa de oviposición más baja (0,49 huevos/hembra/2días comparada con MEcu72 (0,89 y CG489-34 (0,86. Con una tasa de supervivencia muy baja (0,03 MEcu72 fue el único genotipo donde el biotipo B completó su desarrollo de huevo a adulto, necesitando 55,1 días. Los resultados son discutidos evaluando el potencial de adaptación de B. tabaci en Sur América sobre genotipos comerciales de yuca.Abstract: The geminiviruses of cassava mosaic virus (CMGs (Geminiviridae, Begomovirus and their whitefly vector, Bemisia tabaci, produce the major losses in root yield of cassava crops in Asia and Africa. Recent evidence suggests that B. tabaci represents a complex of morphologically

  1. Infestação de Bemisia tabaci biótipo B e Caliothrips phaseoli em genótipos de feijoeiro Infestation of Bemisia tabaci biotype B and Caliothrips phaseoli on bean genotypes

    Directory of Open Access Journals (Sweden)

    Flávio Gonçalves de Jesus

    2010-01-01

    Full Text Available Avaliou-se o comportamento de genótipos de feijoeiro sob a infestação de Bemisia tabaci (Genn. biótipo B e Caliothrips phaseoli (Hood em condições de campo, nas épocas de cultivo "de inverno", "das águas" e "da seca". Adotou-se o delineamento de blocos casualizados em esquema de parcelas sub-subdividida (19x3x6, com 19 genótipos (IAC Tybatã, IAC Una, FT Nobre, Pérola, Gen 96A98-15-3-32-1, Gen 96A45-3-51-52-1, IAC Alvorada, IAC Diplomata, Gen 96A3-P1-1-1, LP 98-122, LP 02-130, LP 01-38, LP 9979, BRS-Pontal, BRS-Requinte, BRS-Triunfo, BRS-Grafite, CV-48 e Z-28, três épocas de cultivos (inverno, águas e seca e seis períodos de avaliação. As avaliações foram realizadas semanalmente, contando-se o número de ovos e ninfas de B. tabaci e ninfas de C. phaseoli em dez folíolos por parcela. Os genótipos IAC Una, Pérola, Gen 96A45-3-51-52-1, Gen 96A98-15-32-1, FT Nobre, IAC Tybatã, IAC Alvorada, LP 02-130, LP 01-38, LP 98-122, IAC Diplomata e Gen 96A3P1-1-1 foram menos ovipositados por B. tabaci no cultivo "das águas". Os genótipos Pérola, Gen 96A45-3-51-52-1, IAC Una, Gen 96A98-15-32-1, IAC Tybatã e FT Nobre foram menos infestados por C. phaseoli. A maior incidência de ninfas de mosca-branca ocorreu no fim de janeiro no cultivo "das águas" e início de maio no cultivo "da seca"; para tripés, foi em junho durante o cultivo "de inverno". A maior incidência da população de B. tabaci e C. phaseoli, ocorreu dos 46 aos 60 dias após a emergência das plantas.The response of bean genotypes to infestation of Bemisia tabaci (Genn. biotype B and Caliothrips phaseoli (Hood in field conditions on the winter, rainy and dry seasons was evaluated. The experiment was arranged in a randomized Sub-divided (19x3x6 blocks design with 19 genotypes (IAC Tybatã, IAC Una, FT Nobre, Pérola, Gen 96A98-15-3-32-1, Gen 96A45-3-51-52-1, IAC Alvorada, IAC Diplomata, Gen 96A3-P1-1-1, LP 98-122, LP 02-130, LP 01-38, LP 9979, BRS-Pontal, BRS

  2. 不同寄主植物上烟粉虱次生共生菌感染与性比相关性%Relationships between infection with facultative symbionts and sex ratio of Bemisia tabaci on different host plants

    Institute of Scientific and Technical Information of China (English)

    瞿钰峰; 李永腾; 刘向东; 方继朝; 郭慧芳

    2015-01-01

    【目的】烟粉虱 Bemisia tabaci (Gennadius)体内次生共生菌感染受寄主植物的影响,一些共生菌会引起害虫的雌性化,明确田间不同寄主植物上害虫种群中共生菌与性比的相关性,可有利于进一步了解烟粉虱田间种群暴发机制。【方法】采集田间不同寄主植物上烟粉虱成虫,观察其性比,并对其中次生共生菌进行分子检测,分析共生菌携带率与性比相关性。【结果】江苏南京地区棉花、番茄、黄瓜和红薯4种寄主植物上烟粉虱次生共生菌 Hamiltonella 和 Rickettsia 感染均存在显著差异,其中 Hamiltonella 为优势共生菌,感染率依次为:棉花>黄瓜>番茄>红薯。寄主植物间 Wolbachia 和 Cardinium 的感染率均无显著差异。各寄主植物上烟粉虱雌性比均高于60%,其中黄瓜上高达75.6%,但不同寄主植物间无显著差异。进一步分析表明,Hamiltonella 和 Rickettsia 感染率均与烟粉虱雌性比呈显著的二次多项式相关性。当Hamiltonella 和 Rickettsia 感染率分别低于69%和5%时,随着感染率提高,烟粉虱雌性比上升,当感染率高于上述值时,则随着感染率增加,雌性比下降。【结论】棉花、番茄、黄瓜和红薯4 种寄主植物上烟粉虱均表现出雌性化,但不同寄主植物间性比无差异,烟粉虱体内次生共生菌与性比存在相关性。%Objectives] Infection of the whitefly, Bemisia tabaci (Gennadius) by facultative symbionts varies with host plant and some facultative symbionts can cause feminization of the host. Studies of the relationship between facultative symbiont infection and sex ratio in field populations of B. tabaci will be helpful to understand the breakout mechanism of this insect pest. [Methods] B. tabaci adults were collected from field populations from four species of host plants in Nanjing, China, and their sex ratios and frequency of symbiont infection determined. [Results

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

    Science.gov (United States)

    Okuda, Mitsuru; Okuda, Shiori; Iwai, Hisashi

    2015-09-01

    Cucurbit chlorotic yellows virus (CCYV) of the genus Crinivirus within the family Closteroviridae is an emerging infectious agent of cucurbits leading to severe disease and significant economic losses. Effective detection and identification methods for this virus are urgently required. In this study, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed to detect CCYV from its vector Bemisia tabaci. LAMP primer sets to detect CCYV were evaluated for their sensitivity and specificity, and a primer set designed from the HSP70h gene with corresponding loop primers were selected. The RT-LAMP assay was applied to detect CCYV from viruliferous B. tabaci trapped on sticky traps. A simple extraction procedure using RNAsecure™ was developed for template preparation. CCYV was detected in all of the B. tabaci 0, 1, 7 and 14 days after they were trapped. Although the rise of turbidity was delayed in reactions using RNA from B. tabaci trapped for 7 and 14 days compared with those from 0 and 1 day, the DNA amplification was sufficient to detect CCYV in all of the samples. These findings therefore present a simple template preparation method and an effective RT-LAMP assay, which can be easily and rapidly performed to monitor CCYV-viruliferous B. tabaci in the field. PMID:25912723

  4. 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. PMID:27273750

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

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    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.

  6. BIO-EFFICACY OF NEWER INSECTICIDES AGAINST TOMATO LEAF CURL VIRUS DISEASE AND ITS VECTOR WHITEFLY (BEMISIA TABACI IN TOMATO

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    Govindappa, M.R

    2013-08-01

    Full Text Available Tomato leaf curl begomovirus and its vector whitaefly (Bemisia tabaci are the major limiting factors, which cause substantial yield loss in tomato. Present investigations on Invitro efficacy of new insecticide molecules on whitefly mortality and leaf curl virus transmission revealed that adult mortality varies with the length of incubation period of different insecticides, as increase in the concentration of insecticides, adult mortality was more in the initial hrs of incubation. Among the test chemicals, cyantraniliprole 10 OD at 60 and 75 g.a.i/ha have knockdown effect and caused 100 per cent mortality at 48 hrs after treatments and also recorded least virus transmission (10 and 5 % respectively. Whiteflies remained active and caused 100 per cent transmission of leaf curl virus in the untreated check. The incidence of B. tabaci and tomato leaf curl virus disease (disease inoculums was stastically varied with respect to different dose of insecticides evaluated at two different levels of observation. Among the different concentrations of new molecule cyantraniliprole (Cyazypyr 10 OD (45, 60 and 75 g.a.i/ha tested, cyantraniliprole 10 OD at 60 and 75 g.a.i/ha. were found more effect in reducing both whitefly and disease incidence at first and final observation with the least whitefly population and leaf curl disease incidence. Correspondingly the yields were high in plot received cyantraniliprole 10 OD 75 g.a.i/ha (32.5tons/ha and significantly superior over the standard check triazophos (23.5tons/ha. followed by cyantraniliprole 10 OD at 60 g.a.i/ha (29.2 tons/ha and cyantraniliprole 10 OD at 45 g.a.i/ha (27.4 tons/ha.

  7. 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)

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

    OpenAIRE

    Sheila Salles de Carvalho; José Djair Vendramim; Rafael Major Pitta; Moacir Rossi Forim

    2012-01-01

    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-ins...

  9. Resistência de genótipos de feijoeiro a Bemisia tabaci biótipo B

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    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.

  10. 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

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

    International Nuclear Information System (INIS)

    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)

  12. 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. PMID:22420748

  13. Efeito de fontes de potássio na infestação de Bemisia tabaci biótipo B e nas características de frutos de tomateiro sob ambiente protegido

    Directory of Open Access Journals (Sweden)

    Feltrin Deise Maria

    2002-01-01

    Full Text Available Bemisia tabaci (Gennadius biótipo B é considerada a espécie de mosca- branca mais nociva à agricultura, pois é responsável por grandes perdas de comercialização e por baixos preços no mercado, principalmente na cultura do tomateiro. Dentre os fatores ambientais, a nutrição mineral pode influenciar a manifestação de resistência da planta em relação ao inseto. Objetivou-se avaliar a influência de diferentes fontes de potássio no tomateiro sobre a infestação de mosca-branca e as principais características dos frutos. O experimento foi realizado no Núcleo Experimental de Campinas (IAC, de dezembro de 1999 a maio de 2000. O híbrido Rocio foi cultivado em "slabs" contendo substrato agrícola, em condições de ambiente protegido. Foram utilizadas quatro soluções nutritivas com variação nas fontes de potássio: KCl + K2SO4 + K2SiO3; KCl + K2SO4; K2SO4 e KCl. Realizaram-se três avaliações do número de ovos + ninfas aos 15, 30 e 45 dias após a infestação com adultos de mosca-branca. Avaliaram-se, ainda, a produtividade e a qualidade dos frutos. Observa-se que as soluções nutritivas com base nas diferentes fontes de potássio não influenciaram a infestação de B. tabaci biótipo B; não se verificou diferença entre os tratamentos em relação à qualidade dos frutos e à produtividade para o híbrido Rocio, em condições de ambiente protegido.

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

    Science.gov (United States)

    Hariton Shalev, Aliza; Sobol, Iris; Ghanim, Murad; Liu, Shu-Sheng; Czosnek, Henryk

    2016-01-01

    The whitefly Bemisia tabaci is a major pest to agricultural crops. It transmits begomoviruses, such as Tomato yellow leaf curl virus (TYLCV), in a circular, persistent fashion. Transcriptome analyses revealed that B. tabaci knottin genes were responsive to various stresses. Upon ingestion of tomato begomoviruses, two of the four knottin genes were upregulated, knot-1 (with the highest expression) and knot-3. In this study, we examined the involvement of B. tabaci knottin genes in relation to TYLCV circulative transmission. Knottins were silenced by feeding whiteflies with knottin dsRNA via detached tomato leaves. Large amounts of knot-1 transcripts were present in the abdomen of whiteflies, an obligatory transit site of begomoviruses in their circulative transmission pathway; knot-1 silencing significantly depleted the abdomen from knot-1 transcripts. Knot-1 silencing led to an increase in the amounts of TYLCV ingested by the insects and transmitted to tomato test plants by several orders of magnitude. This effect was not observed following knot-3 silencing. Hence, knot-1 plays a role in restricting the quantity of virions an insect may acquire and transmit. We suggest that knot-1 protects B. tabaci against deleterious effects caused by TYLCV by limiting the amount of virus associated with the whitefly vector. PMID:27455309

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

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    Patricia Valle Pinheiro

    2009-04-01

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

  16. Evaluación de ácido acético como fumigante de mosquita blanca Bemisia tabaci (Gennadious en laboratorio y campo Assessment of acetic acid like fumigant of silverleaf whitefly Bemisia tabaci (Gennadious in laboratory and field

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    José Alfredo Samaniego Gaxiola

    2012-06-01

    Full Text Available El objetivo de este trabajo fue evaluar la capacidad del ácido acético (AA como fumigante en contra de Bemisia tabaci (moquita blanca que es un plaga de importancia nacional. En el laboratorio, se fumigó el insecto con tres regímenes de dosis - tiempo: (ambos medios, baja - largos y altas - cortos. En el campo, las hojas de calabaza de cuatro variedades fueron fumigadas con 8, 16 y 32 µg ml-1 de AA en tiempos de 20, 40 y 60 min; adicionalmente, se evaluó el daño en las hojas (fitotoxicidad después de fumigarse. En el laboratorio, tiempo de fumigación > 15 miny 8 µg ml-1 de AA mató 100% de la mosquita, mientras que, su supervivencia se redujo 40% al fumigarla ocho horas con 2 µg ml-1de AA; pero la incubación del testigo (mosquita sin fumigar por ≥ 16 h también redujo su supervivencia; entretanto, con 8 y 16 µml-¹ de AA se redujo la supervivencia del insecto desde los cinco minutos (~20-80%. En el campo, la mosquita sobrevivió ~ 40% en las hojas de las cuatro variedades después de fumigarse con AA(8-32 µgml-¹ durante 20 min, pero el insecto prácticamente no sobrevivió al aumentar el tiempo de fumigación a 60 min. Las hojas mostraron un daño severo (fitotoxicidad > al 50% excepto en la dosis de 8 µg ml-¹ a los 20 min con un daño de ~ 20%. Se discuten alternativas del empleo del AA como fumigante.The aim of this work was to assess the capacity of acetic acid (AA like fumigant against Bemisia tabaci (silverleaf whitefly which is a pest of national importance. In laboratory, the bug was fumigated with three doses-time regimes: (both media, low dose-long time and high dose-short time. In field, squash leaves of four varieties were fumigated with 8, 16 and 32 µg ml-¹ of AA during of 20, 40 and 60 min; additionally, it was assessed damage in foils (phytotoxicity after fumigation. In laboratory, fumigation time > 15 min and 8µgml-¹ of AA killed 100% of whitefly, while its survival was reduced 40% when fumigated eight hours

  17. 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

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    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

  18. 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

  19. 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.

  20. ОЦЕНКА УСТОЙЧИВОСТИ НЕКОТОРЫХ СОРТОВ ХЛОПЧАТНИКА К ПОРАЖЕНИЮ ХЛОПКОВОЙ БЕЛОКРЫЛКОЙ (BEMISIA TABACI GENN.)

    OpenAIRE

    Ташпулатов, М.

    2006-01-01

    In 1994-2000 years in Khatlon region cotton fields are noted cotton pests, especially Bemisia tabaci Genn. This pest take place for living under the cotton leaves and sucking leaves liguid till autumn will damage the cotton plant. On the basis of data level of harmfulness and inhabitants of Bemisia tabaci Genn. was find out that the less inhabitation of Bemisia tabaci Genn. is in Mehrgon variety of cotton.

  1. A novel Wolbachia strain from the rice moth Corcyra cephalonica induces reproductive incompatibility in the whitefly Bemisia tabaci: sequence typing combined with phenotypic evidence.

    Science.gov (United States)

    Hu, Hong-Yan; Li, Zheng-Xi

    2015-06-01

    Wolbachia are a group of maternally inherited bacteria frequently found in arthropods and filarial nematodes. They have recently attracted attention for their ecological roles in manipulating host reproduction, their potential use in biological control of pest insects and medical significance. Classification of Wolbachia strains is currently solely based on molecular methods. However, the strains even with identical sequence types may induce different host phenotypes. Here we isolated a Wolbachia strain from the rice moth Corcyra cephalonica (designated as wCcep_B_BJ), which was shown to share multilocus sequence typing and Wolbachia surface protein hypervariable region profiles with a cytoplasmic incompatibility (CI)-inducing strain in supergroup B, but the phenotype wCcep_B_BJ may induce needs to be determined. We thus transinfected it into the whitefly Bemisia tabaci harbouring an A-Wolbachia through nymphal microinjection. Fluorescent in situ hybridization demonstrated that wCcep_B_BJ was successfully transinfected into B. tabaci and transmitted to offspring through host eggs. Reciprocal cross showed that wCcep_B_BJ induced a strong bidirectional CI in the transinfected host without imposing a significant cost on female fecundity. Our results suggest that wCcep_B_BJ may be a promising strain for biocontrol of B. tabaci, an important agricultural pest insect. PMID:25683566

  2. 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.

  3. Effects of elevated CO2 on the interspecific competition between two sympatric species of Aphis gossypii and Bemisia tabaci fed on transgenic Bt cotton

    Institute of Scientific and Technical Information of China (English)

    Zhi-Yi Li; Tong-Jin Liu; Neng-Wen Xiao; Jun-Sheng Li; Fa-Jun Chen

    2011-01-01

    Effects of elevated CO2 (twice ambient vs.ambient) and Bt CrylAc transgene (Bt cotton cv.33B vs.its nontransgenic parental line cv.DP5415) on the interspecific competition between two ecologically similar species of cotton aphid Aphis gossypii and whitefly biotype-Q Bemisia tabaci were studied in open-top chambers.The results indicated that elevated CO2 and Bt cotton both affected the population abundances of A.gossypii and biotype-Q B.tabaci when introduced solely (i.e.,without interspecific competition) or two species coexisted (i.e.,with interspecific competition).Compared with ambient CO2,elevated CO2 increased the population abundances ofA.gossypii and biotype-Q B.tabaci as fed on Bt and nontransgenic cotton on 45 (i.e.,seedling stage) and 60 (i.e.,flowering stage) days after planting (DAP),but only significantly enhanced aphid abundance without interspecific competition on the 45-DAP nontransgenic cotton and 60-DAP Bt cotton,and significantly increased whitefly abundance with interspecific competition on the 45-DAP Bt cotton and 60-DAP nontransgenic cotton.In addition,compared with nontransgenic cotton at elevated CO2,Bt cotton significantly reduced biotype-Q B.tabaci abundances without and with interspecific competition during seedling and flowering stage,while only significantly decreasing A.gossypii abundances without interspecific competition during the seedling stage.When the two insect species coexisted,the proportions ofbiotype-Q B.tabaci were significantly higher than those ofA.gossypii on Bt and nontransgenic cotton at the same CO2 levels,and elevated CO2 only significantly increased the percentages of biotype-Q B.tabaci and significantly reduced the proportions ofA.gossypii on seedling and flowering nontransgenic cotton.Therefore,the effects of elevated CO2 were favorable for biotype-Q B.tabaci to out-compete A.gossypii under the predicted global climate change.

  4. A SURVEY OF SIZES AND WEIGHTS OF BEMISIA TABACI(HOMOPTERA:ALEYRODIDAE)B BIOTYPE LIFE STAGES FROM FIELD GROWN COTTON AND CANTALOUPES%棉花和香瓜的甘薯粉虱Bemisia tabaci(同翅目,粉虱科)B生态型虫体大小和重量的田间调查

    Institute of Scientific and Technical Information of China (English)

    朱昌祺; James S. Buckner; Kamil Karut; Thomas P. Freeman; Dennis R. Nelson; Thomas J. Henneberry

    2003-01-01

    Size and weight measurements were made for all the life stages of Bemisia tabaci (Gennadius) B biotype from field grown cotton ( Gossypium hirsutum L. ) and cantaloupe ( Cucumis melo L., var. cantalupensis )in Phoenix, AZ and Fargo, ND, USA in 2000 and 2001. Nymphal volumes were derived from the measurements.The average nymphal volume increase for settled 1 st to the late 4th instar was exponential. The greatest increase in body volume occurred during development from the 3rd to early 4th instar. Nymphs on cotton leaves were wider,but not longer compared with those on cantaloupe. Ventral and dorsal depth ratios of nymphal bodies from 1st to late 4th instars from cantaloupe leaves were significantly greater compared with those from cotton leaves. During nymphal development from 1st to 4th instar, the average (from the two host species) ventral body half volume increased by nearly 51 times compared with an increase of 28 times for the dorsal body half volume. Adult female and male average lengths, from heads to wing tips, were 1 126 μm and 953 μm, respectively. Average adult female and male weights were 39 and 17 μg, respectively. Average widths, lengths, and weights of eggs from cotton and cantaloupe were, 99 μm, 197 μm, and 0.8 μg, respectively. Average widths, lengths, and weights for exuviae of non-parasitized nymphs from both cotton and cantaloupe were 492 μm, 673 μm, and 1.20 μg, respectively; and widths, lengths, and weights of parasitized nymph exuviae were 452μm, 665 μm, and 3.62 μg, respectively. Both exuviae from non-parasitized and parasitized nymphs from cotton leaves were wider, longer, and heavier than those from cantaloupe leaves.%2000和2001年在美国凤凰城和北达科塔州法哥城田间,调查棉花和香瓜上甘薯粉虱Bemisia tabaci B生态型所有虫期虫体大小和重量.从若虫大小计算出若虫的体积.第一到第四龄晚期,若虫平均体积以指数方式增加.体积增加最快的是第三到第四龄早

  5. 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

    OpenAIRE

    Maria Santana de Araújo Trindade; Adalberto Hipólito de Sousa; Patrício Borges Maracajá; Rui Sales Júnior; Wilson Galdino de Andrade

    2007-01-01

    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); c...

  6. Phylogenetic relationships of native and introduced Bemisia tabaci (Homoptera: Aleyrodidae) from China and India based on mtCOI DNA sequencing and host plant comparisons

    Institute of Scientific and Technical Information of China (English)

    Qiu Baoli; Susan A. Coats; Ren Shunxiang; Ali M. Idris; Xu Caixia; Judith K. Brown

    2007-01-01

    Phylogenetic relationships for Bemisia tabaci were reconstructed by analysis of a ~ 780 bp fragment of the mitochondrial cytochrome oxidase Ⅰ (mtCOI) gene with an emphasis on geographic range and distribution among eight eudicot plant families that are common hosts of B. tabaci worldwide to elucidate key phylogeographic linkages between populations extant in China (n = 31 ) and India ( n = 34). Bootstrap values for the Maximum Parsimony tree were highly robust for all major nodes involving the major Asian clade, subgroups, and sister groups within, at 92%-100%. Between-clade distances for the Southeast Asia and three other major clades, e.g.from sub-Sahara Africa, North Africa-Mediterranean, and the Americas, were approximately > 16 % divergent. Two major Asian subgroups (Ⅰ, Ⅱ) were resolved, which represented populations indigenous to the region, comprising two (Ⅰ a, Ⅰ b) and five (Ⅱ a-e) sister groups, respectively, which diverged by 11%. Two distinct populations from sunflower in Hyderabad grouped separately within the two Asian subgroups. All other populations grouped uniquely within Asian subgroup Ⅱ or Ⅰ. The "B" biotype was identified in 23 collections from China at 97.3 %-99.5 % nucleotide identity with "B" biotype reference sequences; it was not identified in collections from India.The majority of haplotypes were associated with 3-4 plant families, with one exception that for sister group Ⅱd (sesame, India), it might be monophagous. Thus, B. tabaci from the southeastern and near eastern regions of the Asian continent comprise of a large number of ancestral, richly divergent, mostly polyphagous populations. This region is therefore hypothesized to constitute an important Old World center of diversification for the B. tabaci complex, together with sub-Saharan Africa.

  7. 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. PMID:27081849

  8. 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

  9. Only the B biotype of Bemisia tabaci is present on vegetables in São Paulo State, Brazil Somente o biótipo B de Bemisia tabaci ocorre em hortaliças no Estado de São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Kelly Cristina Gonçales Rocha

    2011-02-01

    Full Text Available Bemisia tabaci (Genn. is one of the most important pests in cultivated areas of vegetables and ornamental crops around the world. Based on the mitochondrial cytochrome oxidize I (mtCOI sequence, there is evidence that B. tabaci should be considered a cryptic species complex of 11 groups containing 24 species. Two of the groups, Middle East-Asia Minor 1 and Mediterranean include biotypes B and Q, respectively. In this study we evaluated the mtCOI sequence of B. tabaci populations collected in sites of the state of São Paulo, Brazil. Using PCR-RFLP with Taq I, a typical biotype B profile was obtained for all specimens. Based on the comparison with mtCOI reference sequences we found four haplotypes all belonging to the Middle East-Asia Minor 1. They occurred in the hosts pepper (Capsicum annuum L., tomato (Solanum lycopersicum L., eggplant (Solanum melongena L. and cucurbitaceae plants.Bemisia tabaci (Genn. é considerada uma das mais importantes pragas em cultivos de hortaliças e ornamentais em todo o mundo. Baseado na análise da seqüência mitocondrial (citocromo oxidase I - mtCOI foi proposto recentemente que B. tabaci deva ser considerado um complexo críptico de espécies, contendo 11 grupos e 24 espécies. Dois destes grupos: Middle East-Asia Minor e Mediterranean englobam os biótipos B e Q, respectivamente. Avaliou-se a sequência mtCOI de espécimes de B. tabaci coletados em regiões do estado de São Paulo, Brasil. Por PCR-RFLP utilizando-se a enzima Taq I, pôde-se observar somente o padrão típico de clivagem para o biótipo B. Comparando-se com sequências consenso, todas as moscas brancas foram classificadas no grupo Middle East-Asia Minor e puderam ser separadas em quatro haplótipos, indicando prevalência do biótipo B em áreas de pimentão (Capsicum annuum L., tomate (Solanum lycopersicum L., cucurbitáceas e berinjela (Solanum melongena L. do Estado de São Paulo.

  10. Estadísticos vitales de Bemisia tabaci biotipo B en frijol e interacción con el parasitoide Amitus fuscipennis

    OpenAIRE

    Manzano Martínez María del Rosario; Vélez Mera Cristian Andrés; Mosos Martínez William Andrés

    2009-01-01

    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 (rm) de 0.125. Estos valores son coincidentes con ...

  11. Preferência de Bemisia tabaci biótipo B para oviposição em cultivares de algodoeiro

    OpenAIRE

    Toscano Luciana Cláudia; Santos Terezinha Monteiro dos; Boiça Júnior Arlindo Leal

    2003-01-01

    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 De...

  12. Evaluation of Interspecific Interaction Between Encarsia lutea and Eretomocerus near mundus, the Parasitoids of Cotton Whitefly (Bemisia tabaci) with Host Plants Density Levels and Preference

    Science.gov (United States)

    Arshad Ullah, Muhammad; Abbasi, Khalida Hamid; Bano, Saadia; Khanum, Saeeda

    `Studies were carried out at CABI Biosciences Pakistan Centre, Rawalpindi to evaluate the effects of host plants and insects with host density levels and preference by both these species, i.e., Encarsia lutea and Eretomocerus separately as well as together in competitive situation. Preference of density levels by both parasitoids species showed that density level 20 (cotton leaf disc with 20 Bemisia tabaci nymphs and pupae) was contributed more (42%) preference than other density levels (5, 10, 40, 60 and 80). Different density levels had highly significant effect on settlement time of both species separately while in competitive situation the settlement time of both species was not significantly different from each other on different treatments.

  13. Adult attractiveness and non-preference for oviposition of Bemisia tabaci (Genn. biotype B (Hemiptera: Aleyrodidae in genotypes of Cucurbita spp

    Directory of Open Access Journals (Sweden)

    Ronelza Rodrigues da Costa Zaché

    2013-12-01

    Full Text Available The objective was to evaluate the oviposition preference and attractiveness of squash genotypes (Cucurbita spp. to Bemisia tabaci biotype B. For bioassays, B. tabaci rearing biotype B was kept under greenhouse conditions. Twenty genotypes of Cucurbita spp. (‘Alicia AF 9354’, ‘Aline AF 9353’, ‘Golden Delight’, ‘Nova Caravela’, ‘Menina Morena’, ‘Novita’, ‘AF-6741’, ‘Atlas’, ‘Bárbara 305’, ‘Menina Brasileira’, ‘Caserta’, ‘Itapuã 301’, ‘Tâmara’, ‘Samira’, ‘Canhão Seca Gigante’, ‘Exposição’, ‘Novita Plus’, ‘Daiane’, ‘Formosa’, ‘Sandy’ were evaluated in trials (attractiveness and oviposition choice, under laboratory and greenhouse. The attractiveness (adults/cm2 was assessed et 12, 24, 48 and 72 hours after release. After 72 hours leaves were collected for counting the number of eggs (free choice. The area of the sheets were measured to obtain the number of eggs/cm2 number of adults and / cm 2. The attractiveness index s (AI and oviposition preference index (OPI were calculated, and the genotype ‘Novita’ was adopted as the standard susceptible. The genotype ‘Golden Delight’ was the most attractive to adults of B. tabaci biotype B. ‘Sandy’ ‘Daiane’ and ‘Formosa’ showed low attractiveness and ‘Golden Delight’ was the most atractive to B. tabaci biotype B adults. ‘Sandy’, ‘Exposição’, ‘Daiane’, ‘Atlas’, ‘Tamara’ and ‘Formosa’ expressed no preference for free choise assay. According to the attractiveness index (AI the genotype ‘Golden Delight’ was the most attractive to adults of B. tabaci biotype B, and between repellents stood out ‘Sandy’, ‘Daiane’, ‘Formosa’, ‘Novita Plus’, ‘Atlas’, ‘Bárbara 305’, ‘Canhão Seca Gigante’ and ‘Menina Brasileira’. The genotypes ‘Nova Caravela’, ‘Golden Delight’, ‘Aline AF 9353’ and ‘Samira’ are considered by stimulating oviposition

  14. Cryptic species composition and genetic diversity within Bemisia tabaci complex in soybean in India revealed by mtCOI DNA sequence

    Institute of Scientific and Technical Information of China (English)

    Prasanna H C[1; Kanakala S[2; Archana K[2; Jvothsna p[2; Varma R K[3; Malathi V G[2

    2015-01-01

    Bemisia tabaci is a cryptic species complex, causing signifi(:ant loss on many agriculturally important crops worldwide. Knowledge on species composition and diversity within B. tabaci complex is critical for evolving sustainable pest management strategies. Here we investigate the whitefly species complex in soybean in major soybean growing states of India. The mitochondrial cytochrome oxidase gene subunit-1 (mtCOI) based phylogenetic relationships established using Bayesian methods indicated the existence of three cryptic species namely Asia I, Asia II 1, and Asia II 7. All the haplotypes detected in the study could be assigned to these three cryptic species following the species demarcation criteria of 3.5% divergence threshold. Of these, Asia II 1 was found to be predominant with wide spread distribution across the surveyed regions from cool temperate zones to hot and humid tropical plains. On the contrary, cryptic species Asia II 7 showed localized distribu- tion. The Asia II 1 exhibited the highest haplotype diversity and Asia I showed high level of nucleotide diversity. There was a significantly high genetic differentiation among these three cryptic species. The MEAM 1, a dreadful invasive species was not detected in the specimens tested in the current study. The diversity and distribution of three cryptic species is discussed in the light of current knowledge on distribution of whitefly species in India and yellow mosaic disease observed during sampling survey.

  15. 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

  16. 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

  17. Využití entomopatogenních hub v biologické ochraně proti molici skleníkové Trialeurodes vaporariorum a bavlníkové Bemisia tabaci

    OpenAIRE

    NAVRÁTILOVÁ, Dana

    2007-01-01

    Diploma Thesis concerns with usage of entomopathogenic fungi in system of biological control against greenhouse whitefly Trialeurodoes vaporariorum and sweetpotato whitefly Bemisia tabaci. The Aim of diploma thesis was through in vivo and in vitro experiments determinated the basic evolutional and vegetative characteristics of selected entomopathogenic fungi and compare their effectivity in completed system "plant - pest - pathogenic". All experiments and results are demonstrated in the table...

  18. 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.

  19. 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

  20. Toxicities of five insecticides to Bemisia tabaci B-biotype%5种杀虫剂对B型烟粉虱的毒力测定

    Institute of Scientific and Technical Information of China (English)

    胡彧娴; 郑栋辉; 肖志浩; 刘长明

    2012-01-01

    采用浸叶法分别测定了苦参碱、阿维菌素、氯氰菊酯、灭多威和吡虫啉对B型烟粉虱不同虫态的毒力.结果表明:苦参碱对烟粉虱卵的毒力最高,LC50为0.802 mg·L-1,其毒力是吡虫啉的323.8倍;阿维菌素、苦参碱和吡虫啉对1龄和3龄若虫的毒力均较高,但对1龄若虫的毒力高于3龄若虫;阿维菌素和苦参碱对成虫的毒力较高,分别是吡虫啉的111.6和77.4倍;而灭多威和氯氰菊酯对烟粉虱各虫态均表现出较低的毒力.%Toxicities of raatrine, abamectin, cypermethrin, methomyl and imidacloprid to different development stages of Bemisia tabaci B-biotype were determined using leaf-dipping method. The results showed that matrine had the highest toxicity to eggs of B. tabaci, the LC50 value was 0.802 mg·L-1, which was 323.8 times as high as imidacloprid; abamectin, matrine and imidacloprid showed high toxicities to 1st and 3rd instar nymphs, and the toxicity to 1st instar nymphs was higher than to 3rd instar nymphs; abamectin and matrine had high toxicities to adults, which were 111.6 and 77.4 times as high as imidacloprid respectively; methomyl and cypermethrin had lower toxicities to all development stages of whitellies.

  1. 不同温度下吡虫啉对B型烟粉虱毒杀活性的研究%Influence of temperature on the toxicity of imidacloprid on the different stages of Bemisia tabaci B -biotype (Hemiptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    黄俊; 韦茂兔; 张娟; 沈福泉; 李明江; 陈常理

    2011-01-01

    The effects of imidacloprid on the different stages of Bemisia tabaci B - biotype at the temperatures of22℃, 25℃, 28℃, 31℃ and 34℃ were detected using the dipping egg, impregnation and dipping leaf methods. The results showed that the control effects of imidacloprid on the different stages of B. Tabaci gradually increased with the increasing of temperature, and the 60 mg/L imidacloprid treatment was the most evident. Besides, compared with the treatment of 22% and 34℃, the control effects of 60 mg/L imidacloprid on B. Tabaci eggs, low - instar nymphs, high - instar nymphs and adults rose by 20. 89% , 33. 52% , 33.37% and 17.86% respectively. Consequently, the increasing of temperature has positive effect on the control of B. Tabaci by imidacloprid.%分别采用浸卵法、浸渍法和浸叶法测定了22、25、28、31和34℃下吡虫啉对B型烟粉虱Bemisia tabaci B - biotype不同虫态的控制效果.结果表明,随着温度的升高,吡虫啉对B型烟粉虱不同虫态的控制效果也逐渐上升,当温度上升至34℃时,60 mg/L浓度药液处理下卵、低龄若虫、高龄若虫及成虫死亡率分别较22℃时升高了20.89%、33.52%、33.37%及17.86%.因此,温度提高对吡虫啉防治B型烟粉虱起到了正面效应.

  2. Tomato yellow leaf curl virus infection of tomato does not affect the performance of the Q and ZHJ2 biotypes of the viral vector Bemisia tabaci

    Institute of Scientific and Technical Information of China (English)

    Meng Li; Jian Liu; Shu-Sheng Liu

    2011-01-01

    To better understand the etiology of begomovirus epidemics in regions under invasion we need to know how indigenous and invasive whitefly vectors respond to virus infection.We investigated both direct and indirect effects of infection with Tomato yellow leaf curl virus(TYLCV)on the performance of the invasive Q biotype and the indigenous Asian ZHJ2 biotype of whitefly Bemisia tabaci.The Q biotype performed better than the ZHJ2 biotype on either uninfected or virus-infected tomato plants.However,virus-infection of host plants did not,or only marginally affected,the performance of either biotype of whiteflies m terms of fecundity,longevity,survival,development and population increase.Likewise,association of the vectors with TYLCV did not affect fecundity and longevity of the Q or ZHJ2 biotypes on cotton,a non-host of TYLCV.These results indicate that the alien Q biotype whitefly,but not the indigenous ZHJ2 biotype,is likely to become the major vector of TYLCV in the field and facilitate virus epidemics.

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

    Science.gov (United States)

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

    2015-06-01

    Cotton whitefly, Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae) is a major sucking pest in many agricultural and horticultural cropping systems globally. The frequent use of insecticides of different mode of action classes resulted in populations resisting treatments used to keep numbers under economic damage thresholds. Recently it was shown that resistance to neonicotinoids such as imidacloprid is linked to the over-expression of CYP6CM1, a cytochrome P450 monooxygenase detoxifying imidacloprid and other neonicotinoid insecticides when recombinantly expressed in insect cells. However over-expression of CYP6CM1 is also known to confer cross-resistance to pymetrozine, an insecticide not belonging to the chemical class of neonicotinoids. In addition we were able to demonstrate by LC-MS/MS analysis the metabolisation of pyriproxyfen by recombinantly expressed CYP6CM1. Based on our results CYP6CM1 is one of the most versatile detoxification enzymes yet identified in a pest of agricultural importance, as it detoxifies a diverse range of chemical classes used to control whiteflies. Therefore we developed a field-diagnostic antibody-based lateral flow assay which detects CYP6CM1 protein at levels providing resistance to neonicotinoids and other insecticides. The ELISA based test kit can be used as a diagnostic tool to support resistance management strategies based on the alternation of different modes of action of insecticides. PMID:26047106

  4. Presença e impacto de Bemisia Tabaci (genn.) (homoptera: aleyrodidae) em culturas hortícolas em Portugal Presence and impact of Bemisia Tabaci (genn.) (homoptera: aleyrodidae) in vegetable crops in Portugal

    OpenAIRE

    Célia Mateus; Fernanda Amaro; Diamamtina Louro; António Mexia

    2008-01-01

    Em Portugal, emisia tabaci (Genn.) (Homoptera: Aleyrodidae) foi detectada pela primeira vez em 1992, em culturas hortícolas. Desde 1995, é uma praga importante no Algarve, onde está presente nas estufas durante todo o ano, com níveis de infestação elevados no Verão. A partir de 2006, foi considerada também estabelecida no Alentejo e em parte do Ribatejo e Oeste. A espécie constitui um grave problema em diversas culturas hortícolas, não só pelos prejuízos directos, mas, principalmente, pela su...

  5. Identificación y caracterización molecular de virus transmitidos por mosca blanca bemisia tabaci que infectan tomate en la región andina de Colombia

    OpenAIRE

    Betancur Pérez, Jhon Fredy

    2012-01-01

    Los Begomovirus son virus que pertenecen a la familia Geminiviridae, se caracterizan por infectar plantas dicotiledóneas y ser transmitidos por mosca blanca (Bemisia tabaci, biotipo B). El genoma está constituido por una o dos moléculas circulares de ADN de cadena sencilla, cuyos genes están asociados con procesos de replicación, transcripción, encapsidación y movimiento. Los Begomovirus son considerados virus emergentes debido al aumento en la incidencia y severidad en las enfermedades causa...

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

    OpenAIRE

    Eneida Torres Cabra; Javier Hernández-Fernández

    2014-01-01

    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 realiz...

  7. 不同类型杀虫剂对北京地区Q型烟粉虱的毒力测定%Toxicities of Different Insecticides to Q-Type Bemisia tabaci in Beijing

    Institute of Scientific and Technical Information of China (English)

    宫亚军; 石宝才; 朱亮; 康总江; 王泽华; 魏书军

    2011-01-01

    [目的]近年来Q型烟粉虱在我国许多地区危害严重,但关于Q型烟粉虱对杀虫剂的抗性研究甚少.采用浸叶生测法分别测定了7种杀虫剂对北京地区Q型烟粉虱成虫的毒力.[结果]结果表明7种药剂对烟粉虱成虫的毒力排序:阿维菌素>甲氨基阿维菌素苯甲酸盐>多杀霉素>啶虫脒>吡虫啉>毒死蜱>敌敌畏.[结论]在北京地区防治烟粉虱时应选用敏感性高的抗生素类杀虫剂,交替使用新烟碱类农药,限制使用有机磷类农药.%[Aims] Q-type whitefly Bemisia tabaci caused serious damages in many areas in China in recent years.However, there are few studies on resistance of this pest to insecticides. Here, we tested the toxicities of seven insecticides to adults of Q-type B. tabaci by leaf-dipping method in Beijing. [Results] The results showed that the descending order of toxicity of these seven insecticides to B. tabaci adults is abamectin, emamectin benzoate, spinosad, acetamiprid,imidacloprid, chlorpyrifos, dichlorvos. [Conclusions] Thus, antibiotic insecticides with high sensitivity and alternate use of neonicotinoid pesticides are recommended in controlling whitefly Bemisia tabaci in Beijing areas. However, usage of organophosphorus pesticides should be restricted.

  8. Evaluation on the Effect of Spirotetramat on Controlling Bemisia tabaci%螺虫乙酯对烟粉虱的防治效果评价

    Institute of Scientific and Technical Information of China (English)

    谢文; 吴青君; 徐宝云; 王少丽; 张友军

    2011-01-01

    The bioassay research of spirotetramat in Bemisia tabaci egg, nymph and adult were investigated. 96 % movento showed high toxicity to egg and nymph of B.tabaci, which had no significant difference compared with that of 95 % imidacloprid used as a controlling pesticide and LC50 were 18.91 mg ? L-1 and 14.97 mg ? L-1 , respectively. However, 96 % movento showed low toxicity to adult of B.tabaci and Lcso were up to 453.34 mg ? L , which was significantly higher than that of 95 % imidacloprid. On the other hand, 24 % movento SC has good control effect and persistence to B.tabaci through field experiment. The combinations effect of movento and biopower were obviously better than that of movento used alone. The results showed that control effects of 24 % movento SC biopower 0.2 % ( 3.6 g ? Hm" ) were 64.91 %-66.92 %, 82.00 %-82.59 %, 88.11 %-89.97 %, 89.99 %-93.94 % and 91.10 %-93.56 % after spaying 1-28 days, respectively.%采用室内毒力测定与田间试验相结合的方法,研究了螺虫乙酯( Movento)对烟粉虱的防治效果.室内毒力测定结果表明:96%螺虫乙酯原药对烟粉虱卵和若虫都具有非常高的杀虫活性,LC50分别为18.91 mg·L-1和14.97 mg·L-1,与对照95%吡虫啉没有显著差异;但对烟粉虱成虫的杀虫效果并不十分理想,LC50达到了453.34 mg·L-1,且显著高于对照95%吡虫啉.田间试验结果表明:24%螺虫乙酯悬浮剂(SC)对烟粉虱有良好的防效和持效性,且螺虫乙酯与Biopower(助剂)混用的防效明显优于螺虫乙酯单独使用的效果;螺虫乙酯与0.2%[0.24 g·(667 m2)-1] Biopower混用,药后1~28 d对烟粉虱的防效分别为64.91%~66.92%、82.00%~82.59%、88.11%~89.97%、89.99%~93.94%和91.10%~93.56%.

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

    Directory of Open Access Journals (Sweden)

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

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    Marilene Fancelli

    2008-12-01

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

  11. 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

  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

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    Antônio Lopes da Silva

    2007-09-01

    Full Text Available

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

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

  13. Avaliação da Dispersão primária e secundária do Tomato severe rugose virus para genótipos de Capsicum spp. por Bemisia tabaci MEAM1

    OpenAIRE

    Késsia de Fátima Cunha Pantoja; Kelly Cristina Gonçales Rocha; Edson Luiz Lopes Baldin; Marcelo Agenor Pavan; Renate Krause-Sakate

    2014-01-01

    A mosca branca Bemisia tabaci (Hemiptera: Aleyrodidae) é considerada uma das pragas agrícolas mais ameaçadoras em todo o mundo, pelo seu efeito direto na sucção de seiva das plantas e principalmente pelo seu efeito indireto de transmitir vírus, em especial os begomovírus. No Brasil, a espécie de begomovírus predominante em solanáceas é o Tomato severe rugose vírus - ToSRV. Uma possibilidade de manejo da doença é a utilização de cultivares resistentes ou tolerantes tanto ao vírus, como ao inse...

  14. 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

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    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

  15. Avaliação da Dispersão primária e secundária do Tomato severe rugose virus para genótipos de Capsicum spp. por Bemisia tabaci MEAM1

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    Késsia de Fátima Cunha Pantoja

    2014-12-01

    Full Text Available A mosca branca Bemisia tabaci (Hemiptera: Aleyrodidae é considerada uma das pragas agrícolas mais ameaçadoras em todo o mundo, pelo seu efeito direto na sucção de seiva das plantas e principalmente pelo seu efeito indireto de transmitir vírus, em especial os begomovírus. No Brasil, a espécie de begomovírus predominante em solanáceas é o Tomato severe rugose vírus - ToSRV. Uma possibilidade de manejo da doença é a utilização de cultivares resistentes ou tolerantes tanto ao vírus, como ao inseto vetor. Foram avaliados neste trabalho a dispersão primária e secundária do ToSRV por Bemisia tabaci, espécie MEAM1, também conhecida como biótipo B, em cultivares tolerantes ao ToSV Capsicum baccatum (IAC-1357 C. annuum (IAC-1566 e C. frutescens (IAC-1544. O genótipo (IAC-1544 apresentou menor número de plantas infectadas pelo ToSRV no ensaio de dispersão primária e nenhuma eficiência na transmissão do isolado na dispersão secundária. Estes resultados colaboram para o melhoramento de pimentão e pimentas visando a resistência ao ToSRV e seu inseto vetor.

  16. Assessment of the Bemisia tabaci CYP6CM1vQ transcript and protein levels in laboratory and field-derived imidacloprid-resistant insects and cross-metabolism potential of the recombinant enzyme

    Institute of Scientific and Technical Information of China (English)

    Emmanouil Roditakis; Evangelia Morou; Anastasia Tsagkarakou; Maria Riga; Ralf Nauen; Mark Paine; Shai Morin; John Vontas

    2011-01-01

    Over-expression of the cytochrome P450 CYP6CM1 gene has been associated with imidacloprid resistance in a number of Q and B biotype Bemisia tabaci laboratory strains from distinct geographical origins worldwide.We recently demonstrated that the Q biotype version of the CYP6CM1 protein(CYP6CM1vQ)is capable of metabolizing imidacloprid.Here,we show that the levels of BtCYP6CM1vQ were also elevated in laboratoryresistant strains and field-derived populations,with variable imidacloprid resistance levels,collected in Crete.High levels of CYP6CM1vQ transcripts were also determined in survivors of a heterogeneous field population,after exposure to discriminating imidacloprid dosage.Using peptide antibody-based detection assays,we demonstrated that in line with transcriptional data,the YP6CM1vQ protein levels were higher in imidacloprid-resistant insects,which further implicates the gene as the causal factor of resistance.Finally,assessment of the cross-metabolism potential of CYP6CM1vQ against additional neonicotinoid olecules used for B.tabaci control revealed that clothianidin and thiacloprid,but not acetamiprid or thiamethoxam,are metabolized by the recombinant enzyme in vitro.

  17. The trapping effect of piemarker in cabbage fields for Bemisia tabaci and the evaluation of chemical control%苘麻对甘蓝田烟粉虱诱集效果及药剂防治评价

    Institute of Scientific and Technical Information of China (English)

    谭永安; 柏立新; 肖留斌; 魏书艳; 赵洪霞

    2011-01-01

    本文针对烟粉虱Bemisia tabaci在不同寄主苘麻Abutilon theophrasti Medic和甘蓝Brassinca oleracea上的嗜好性、趋性、田间种群动态进行了研究,并设计苘麻不同种植方式和配套施药评价苘麻对烟粉虱的诱集防治效果.室内趋性试验结果表明,接虫60h后苘麻上的成虫数是甘蓝上的5.5倍,若虫数为4.7倍.在大田甘蓝生育期内,苘麻对烟粉虱成、若虫的诱集效果分别可达76.8%和60.1%,说明苘麻对烟粉虱具极显著的诱集作用.苘麻不同种植方式诱集烟粉虱的效果结果表明,点状分布种植格局上的烟粉虱成、若虫数量与条状和片状分布种植上烟粉虱数量相比差异显著.配套施药试验结果表明,苘麻喷施10%吡虫啉可湿性粉剂,10%高渗四氟乳油,1.8%阿维菌素乳油,0.3%印楝素乳油,25%阿克泰水分散粒剂5种药剂7d后对烟粉虱成、若虫的防治效果分别为74.38%~94.86%和68.91%~93.29%,以阿克泰和阿维菌素防治效果最好.%In this paper, the preference, tropism and field population dynamics of Bemisia tabaci in different host piemarker and cabbage were studied, and we designed different planting types and insecticide application on the piemarker plant for the effect of trap control. The result indicated that the piemarker plants showed strong attraction to B. tabaci adults and nymphs, when insects observed after 60 h among the indoor trend test, the number of adults on the piemarker was cabbage 5. 5 times and 4. 7 times of nymphs. Through the entire cabbage growth period in field, the effects of trapping to B. tabaci adults and nymphs were 76. 8% and 60. 1% , respectively. There was significant difference between different planting types for trapping B. tabaci adults and nymphs, the attractive efficiency from single -planting piemarker was much more as compared to the planting types of the strip - planting and plot -planting. The insecticide application of 10

  18. 大草蛉幼虫对烟粉虱的捕食功能反应及捕食行为观察%The Predation Function Response and Predatory Behavior Observation of Chrysopa pallens Larva to Bemisia tabaci

    Institute of Scientific and Technical Information of China (English)

    刘爽; 王甦; 刘佰明; 周长青; 张帆

    2011-01-01

    [Objective] The objective of this study is to evaluate the potential regulation capacity of Chrysopa pallens to Bemisia tabaci, and analyze the function response, searching rate and relative predatory behaviors of C. pallens on B. tabaci egg,nymph and pupa in lab conditions. [ Method ] Different prey densities of egg, nymph and pupa orB. tabaci were set up as different treatments for evaluating predatory capacity of3rd instar larva C pallens. The net aggregation of prey consumed and prey consumed ratio in each density were recorded and analyzed. Furthermore, the predatory period was classified into different independent behavior events and evaluated each event in the way of occurrence frequency and ratio of each behavior event to the total duration of predation. The description of each event was also executed at the same time. [Result] The results showed that the function response of C. pallens 3rd instar larva on B. tabaci egg, nymph and pupa were fitted to Holling Ⅱ & Ⅲ formulas. In lab controlled conditions,the predatory capacities of C. pallens on B. tabaci egg, nymph and pupa increased with the increasing prey density. The instantaneous attacking rate was increased with the increasing of target development stages, and the variation of dealing duration was nymph > pupae > egg. On the contrast, the best searching density was the lowest in nymph treatment. Furthermore, the evaluation of searching rate showed that the searching rate of C. pallens on B. tabaci increased with the increasing of target development stages. When C. pallens preyed egg and nymph, the percentage of walking and searching behavior were the most and second. But in pupa treatment, the searching behaviour was the first place and the predation was the second. Similarly, the frequency of each behavior was shown significant differences in predation courses. [ Conclusion ] The present study demonstrated that the predatory capacity of C. pallens larva to B. tabaci egg, nymph and pupa

  19. Resistance of tomato genotypes to the silverleaf whitefly mediated by acylsugars Resistência de genótipos de tomateiro a Bemisia tabaci biótipo B, mediada por acilaçúcares

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    Juliano TV de Resende

    2009-09-01

    Full Text Available Acylsugars in the leaflets of the wild accession LA-716 (Lycopersicon pennellii gives resistance to Bemisia spp., which causes expressive losses to the tomato crop. The goal of this work was to evaluate the resistance to the silverleaf whitefly (Bemisia tabaci biotype B of previously selected genotypes, based on the level of acylsugars in the leaflets. F2BC1 plants {F2[Lycopersicon esculentum TOM 584 x (L. esculentum TOM 584 x L. pennellii LA-716]} were selected for extreme contents of acylsugars: BPX-370B pl#30-275, BPX-370B pl#79-278, BPX-370B pl#30-380, BPX-370B pl#25-271 (high contents, BPX-370B pl#30-02, BPX-370B pl#30-142 (low contents. These genotypes, along with the parents TOM 584 and LA-716, were submitted to a silverleaf whitefly infestation. Oviposition and nymph development were evaluated. The oviposition on the genotypes BPX-370B pl#30-275 and BPX-370B pl#30-380 was significantly lower to that which occurred on the genotype TOM 584 and in the other genotypes of the F2RC1 generation. The four genotypes selected for high acylsugar contents presented the lowest number of nymphs, except to LA-716. Although the number of eggs in the BPX-370B pl#25-271 and BPX-370B pl#79-278 genotypes (high contents was elevated, the number of nymphs was reduced, similarly to the other high-acylsugar genotypes, probably due to antibioses effect.Acilaçúcares presentes nos folíolos do acesso selvagem 'LA-716' (Lycopersicon pennellii conferem resistência a moscas-brancas (Bemisia spp., causadoras de danos expressivos à cultura do tomate. O objetivo do trabalho foi avaliar a resistência de genótipos de tomateiro à mosca-branca Bemisia tabaci biótipo B, com base nos teores de acilaçúcares nos folíolos. Foram selecionadas plantas F2RC1{[L. esculentum 'TOM-584' x (L. esculentum 'TOM-584' x L. pennellii 'LA-716']} para teores extremos de acilaçúcares: BPX-370B pl#30-275, BPX-370B pl#79-278, BPX-370B pl#30-380, BPX-370B pl#25-271 (altos teores, BPX

  20. A method for establishing a Bemisia tabaci population infected with Rickettisa massilia%一种含特异性侵染内共生菌 Rickettisa massilia的烟粉虱种群建立方法

    Institute of Scientific and Technical Information of China (English)

    杨义婷; 张焱; 郭建洋; 郭建英; 万方浩

    2015-01-01

    Objectives] The whitefly, Bemisia tabaci (Gennadaius), is widely distributed in over more than 90 countries and all the world’s regions except Antarctica. Because of its wide host range and capacity to cause serious damage to agricultural crops this species is a particularly destructive pest. The endosymbionts of B. tabaci contribute both to its distribution and host fitness. However, most of these endosymbionts are secondary ones that are very difficult to culture in vitro. [Methods] Whiteflies were collected and reared in a laboratory. One pair of species-specific PCR primers based on a fragment of the known mitochondrial DNA cytochrome oxidaseⅠ(mtDNA COⅠ)sequence was used to diagnose the biotype of the collected specimens. Next, a specific primer was designed to detect whitefly endosymbionts. [Results] The biotype of the B. tabaci specimens collected was MED (previously called the Q biotype). After five generations of population screening, a stable whitefly population carrying and transmitting the endosymbiont Rickettsia to subsequent generations was established. [Conclusion] The method can produce a stable Rickettsia-infected whitefly population, which is useful for studying the interactions between whiteflies, their endosymbionts, and host plants. This method lays a foundation for investigating the role of Rickettsia in the biology of B. tabaci.%【目的】烟粉虱 Bemisia tabaci(Gennadaius)广泛分布于全球除南极洲外各大洲的90多个国家和地区,其寄主范围广,危害严重,属于农业上的重要害虫。烟粉虱体内的内共生菌有助于其扩散传播,提高其寄主适合度,但其体内的内共生菌大都为次生内共生菌,很难进行体外培养,因此,加大了其内共生菌研究的难度。【方法】采集我国部分地区的烟粉虱种群,然后利用基于 mtDNA COⅠ基因的种特异性引物进行种群生物型鉴定,再用内共生菌的特异性引物来鉴定含有特异性

  1. Bemisia: bionomics and management of a global pest

    Science.gov (United States)

    Bemisia tabaci has distinguished itself from the more than 1000 whitefly species in the world by it adaptability, persistence and potential to damage a wide range of agricultural and horticultural crops in all six of the world’s inhabited continents. B. tabaci inflicts plant damage through direct f...

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 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

  4. Gene expression profiling of the whitefly(Bemisia tabaci)Middle East-Asia Minor 1 feeding on healthy and Tomato yellow leaf curl China virus-infected tobacco

    Institute of Scientific and Technical Information of China (English)

    Jun-Min Li; Yong-Ming Ruan; Fang-Fang Li; Shu-Sheng Liu; Xiao-Wei Wang

    2011-01-01

    Begomoviruses are exclusively transmitted by whitefly(Bemisia tabaci)in a circulative,non-propagative manner.The influences of begomoviruses on whitefly vector are complex with both direct and indirect effects.However,the molecular mechanisms underlying these effects are poorly understood and the transcriptional profiles of whitefly on healthy and virus-infected plants have not yet been studied.Using suppression subtractive hybridization,we investigated the differentially expressed genes in whitefly Middle East-Asia Minor 1 feeding on healthy and Tomato yellow leaf curl China virus(TYLCCNV)infected tobacco.From the forward cDNA library,124 differentially expressed expression sequence tags(ESTs)were obtained which represent up-regulated genes in the whiteflies feeding on the infected tobacco.From the reverse library,112 ESTs were isolated which represent down-regulated genes.Among the up-regulated genes,we identified several genes that are probably involved in direct interaction between whitefly and TYLCCNV,including a 26/29-kDa proteinase that appears to participate in the elimination of foreign proteins,heparan sulfate proteoglycan which mediates the entry of several viruses into host cells and two genes of Rickettsia-a secondary endosymbiotic bacterium of whitefly.In addition,we identified a number of genes involved in metabolism,transcription and translation which might be the result of indirect effects of TYLCCNV on the whitefly via host plants.Collectively,our results suggest that TYLCCNV-infected tobacco changes the gene expression profiles of whitefly via both direct and indirect interactions.This study revealed a number of genes involved in whitefly-TYLCCNV-tobacco interactions and provided useful information for future study on this complex system.

  5. Toxicity of spirotetramat to Bemisia tabaci biotype B and the impact on the biological parameters%螺虫乙酯对B型烟粉虱毒力及部分生物学参数的影响

    Institute of Scientific and Technical Information of China (English)

    戈大庆; 姜兴印; 王燕; 李俊虎; 段强

    2011-01-01

    In order to value the bioactivity and impact on the biology of spirotetramat against Bemisia tabaci biotype B, the toxicity of spirotetramat and imidacloprid (control agent) to different instar nymphs of B. tabaci biotype B and the effects of the longevity, fecundity and eggs hatchability were measured in the laboratory by using egg-dipping and leaf-dipping. The toxicity of the 2nd instar nymph is high after treatment by spirotetramat, the LCso was 4.07 mg/L, it was 2.73 times to the toxicity of imidacloprid, toxicity was low to the eggs and adults, and lower than that of imidacloprid. Longevity of the B. tabaci biotype B was 17.3 days after treatment with 12.5 mg/L spirotetramat, it was significantly shorted compared with the contrast experiment (treatment without pesticides), while imidacloprid was insignificant. The fecundity was 5 and the eggs hatching rate was 3.23% after treatment with 12.5 mg/L spirotetramat, which has significantly inhibition to the fecundity and the eggs hatching, and it was significantly lower than those treated with imidacloprid and the contrast experiment. It was no significant differences between imidacloprid and the contrast experiment. The repellent action was 52% to the adults of spirotetramat after 24 h treated with 100 mg/L spirotetramat, and the repellent action was not very good.%为系统评价新药剂螺虫乙酯(spirotetramat)对B型烟粉虱(Bem isia tabacibiotype B)的生物活性及生物学参数的影响,采用浸渍法测定了螺虫乙酯及对照药剂吡虫啉对B型烟粉虱各个虫态的室内毒力、成虫寿命、产卵量及所产卵孵化率的影响。结果表明,螺虫乙酯对2龄若虫毒力最高,LC50为4.07mg/L,为吡虫啉的2.73倍,对卵及成虫毒力较低,且显著低于吡虫啉;12.5 mg/L螺虫乙酯处理后,成虫寿命为17.3天,较空白对照显著缩短,吡虫啉与空白对照无显著差异;12.5mg/L螺虫乙酯处理后平均产卵量为5.0粒,所

  6. Antenna Excision and Its Effects on the Spouse Selection Behavior of Sweetpotato Whitefly Bemisia tabaci%烟粉虱触角的切除及其在配偶选择过程中的作用

    Institute of Scientific and Technical Information of China (English)

    范许哲; 程婷; 郭秋; 尹祥杰; 任顺祥; 邱宝利

    2015-01-01

    烟粉虱是全世界分布的农业重大害虫,是一个由至少24个存在交配行为隔离的生物型组成的种的复合。研究不同体积分数酒精对烟粉虱麻醉效应的基础上,比较了触角切除与否对B生物型烟粉虱雄成虫对同型异型烟粉虱雌成虫择偶行为的影响。结果表明,综合考虑苏醒时间与对烟粉虱的伤害程度2个因素,25%乙醇是麻醉烟粉虱以满足其触角切除时间需要的最佳体积分数。在10 min配偶选择过程中,触角正常的B型烟粉虱雄成虫对B型雌成虫的平均择偶滞留时间为117.3 s,远远长于对Q和Cv型烟粉虱雌成虫的选择时间(43.1 s和39.8 s),其进入B型烟粉虱雌成虫所在区域的平均次数(1.79次)也明显多于进入Q和Cv型所在区域的次数(0.47次,0.89次);而当触角切除后,B型烟粉虱雄成虫对B、Q和Cv型烟粉虱雌成虫择偶滞留时间分别为116.2,110.7,110.1 s,进入相应处理区的次数分别为0.59、0.61和0.56次,三者之间均无明显差异。表明触角正常的B生物型烟粉虱雄成虫择偶时显著倾向于选择同型雌成虫,而触角切除后的B生物型烟粉虱雄成虫对同型和异型雌成虫的选择无明显差异,因此推断触角对烟粉虱的择偶行为及效率具有重要影响。%The whitefly Bemisia tabaci is one of the most damaging agricultural pests distributed over the world,which has been identified as a species complex consists of at least 24 different reproductive isolated bio-types.In the present study,the anesthetizing effects of gradient concentration alcohol (15%-95%) on B.tabaci were tested,and the effects of antenna excision on the spouse selection behavior of the male adults of B.tabaci B biotype were studied in a four-arm olfactometer.The results indicated that 25%alcohol was the optimum concentration for B.tabaci anesthesia concerning the physiological harm to the whitefly

  7. Oviposição de Bemisia tabaci (genn. (Homoptera: aleyrodidae em três variedades de soja sem chance de escolha Oviposition of Bemisia tabaci (genn. (homoptera:aleyrobidae on three soybean varieties in a non-choice type of experiment

    Directory of Open Access Journals (Sweden)

    André Luiz Lourenção

    1982-01-01

    Full Text Available A non-choice type of experiment was conducted in a greenhouse at Campinas to study the oviposition of B. tabaci on two introductions (PI 171451 and PI 229358 and one commercial variety (Santa Rosa of soybean. Previously these introductions were less oviposited by the whitefly in a free-choice type of experiment when compared to commercial varieties. The observed average number of eggs per square centimeter of leaf were 0.82, 0.42 and 0.41 for 'Santa Rosa' susceptible, PI 171451 (resistant and PI 229358 (resistant, respectively. These results showed that the lower rate of for oviposition observed previously is maintained when the insect does not have a chance to oviposit on a susceptible variety.

  8. Effects of the volatiles from different tomato varieties on host selection behavior of B-biotype Bemisia tabaci%不同番茄品种挥发物对B型烟粉虱寄主选择行为的影响

    Institute of Scientific and Technical Information of China (English)

    赵艳群; 赵金瑞; 毛黎娟; 施祖华

    2012-01-01

    采用顶空固相微萃取和气相色谱-质谱法鉴定了6个番茄品种(浙杂809、浙杂203、合作903、凯特一号、黄椭圆和金妃)植株挥发物的成分,并利用Y型嗅觉仪测定了烟粉虱对不同番茄品种植株及其挥发物的嗅觉反应.结果表明:从6个番茄品种中共鉴定出13种化合物,其主要成分为萜类化合物,品种间挥发物的组成成分和各成分所占比例存在差异.(+)-3-蒈烯和β-石竹烯对B型烟粉虱的驱避性较其他萜类强.烟粉虱对含萜类挥发物种类多、比例高的品种(如浙杂809和浙杂203)选择性较弱,而对含萜类挥发物种类少、比例低的品种(如黄椭圆和金妃)选择性较强.%By the methods of headspace solid-phase micro extraction and gas chromatography-mass spectrometry, and using Y-type olfactometer, this paper identified the volatiles from six tomato varieties (Zheza 809, Zheza 203, Hezuo 903, Kate No. 1, Huangtuoyan, and Jinfei) , and bio-assayed the olfactory responses of female B-biotype Bemisia tabaci to the tomato plants and their released volatiles. Thirteen kinds of compounds in the volatiles collected from the six tomato varieties were identified, among which, terpenoids were the main components. However, the compositions and contents of the volatiles differed with tomato varieties. (+)-3-carene and β-caryophyllene showed stronger repellency than other terpenoids to B-type B. tabaci. B-type B. tabaci showed the lowest preference to the tomato varieties such as Zheza 809 and Zheza 203 which contained more kinds of terpenoids and had higher proportion of terpenoids in the volatiles, and showed the greatest preference to the varieties like Huangtuoyan and Jinfei which contained fewer kinds of terpenoids and had lower proportion of terpenoids in the volatiles.

  9. 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

  10. 不同叶面肥对番茄植株生理生化及烟粉虱种群生态的影响%Effects of different foliar fertilizers on the physiology and biochemistry of tomato and population ecology of Bemisia tabaci

    Institute of Scientific and Technical Information of China (English)

    庞淑婷; 董元华

    2013-01-01

    利,但同时会延长烟粉虱的发育历期,且氨基酸叶面肥处理番茄上的烟粉虱雌成虫寿命和生殖力并非最高,抵消了营养对烟粉虱的有利作用.同时,氨基酸叶面肥不会提高烟粉虱的内禀增长率,也就是不会促进烟粉虱的种群增长,在生产中有良好的应用前景.%Fertilization, an important resource of plant nutrient, has been found to affect the development and reproduction of herbivores and their ability to damage plants. The influences of amino acid foliar fertilizer, phytonutrient and branched-chain amino acids on the growth and nutritional status of tomato and then on the development, survival and reproduction of Bemisia tabaci were studied in the laboratory under condition of (25±1) ℃; L : D = 14 h : 10 h; and 70%~80% RH. Nymph size and fecundity of B. tabaci were also observed and the potential of amino acid foliar fertilizer application in practice was discussed. Compared with the control, amino acid foliar fertilizer significantly promoted tomato growth which was evident in increased plant height, leaf stentering and leaf area. Phytonutrient also promoted plant growth but to a lesser degree than amino acid fertilizer. Except for nitrogen and sugar, minerals and nutrient contents in tomato leaves varied with fertilizers treatments. The concentrations of phosphorus, protein and free amino acid in tomato leaves were positively correlated with several tomato growth parameters, including plant height, leaf stentering, and leaf area. Negative correlation was observed between potassium and these parameters. Chlorophyll and water contents in tomato leaves showed minimal differences among treatments. The developmental duration of B. tabaci was longest on tomatoes treated with amino acid foliar fertilizer (22.95 d), followed by those treated with phytonutrient (22.83 d), and was shortest on control treatments (21.78 d). B. tabaci survival rate changed little under different foliar fertilizers

  11. Effects of selected defoliants in combination with insecticides on sweetpotato whitefly (Hemiptera: Aleyrodidae) and its parasitoids in cotton

    Science.gov (United States)

    Effects of two defoliants, Def (S, S, Stributylphosphorotrithioate) and Dropp (thidiazuron) alone and in combination with two commonly used insecticides, a pyrethroid, Karate (lambda-cyhalothrin) and an organophosphate, Guthion (azinphosmethyl) on sweetpotato whitefly, Bemisia tabaci Gennadius Bioty...

  12. Biology and management of Bemisia whitefly vectors of cassava virus pandemics in Africa.

    Science.gov (United States)

    Legg, James P; Shirima, Rudolph; Tajebe, Lensa S; Guastella, Devid; Boniface, Simon; Jeremiah, Simon; Nsami, Elibariki; Chikoti, Patrick; Rapisarda, Carmelo

    2014-10-01

    Cassava mosaic disease and cassava brown streak disease are caused by viruses transmitted by Bemisia tabaci and affect approximately half of all cassava plants in Africa, resulting in annual production losses of more than $US 1 billion. A historical and current bias towards virus rather than vector control means that these diseases continue to spread, and high Bemisia populations threaten future virus spread even if the extant strains and species are controlled. Progress has been made in parts of Africa in replicating some of the successes of integrated Bemisia control programmes in the south-western United States. However, these management efforts, which utilise chemical insecticides that conserve the Bemisia natural enemy fauna, are only suitable for commercial agriculture, which presently excludes most cassava cultivation in Africa. Initiatives to strengthen the control of B. tabaci on cassava in Africa need to be aware of this limitation, and to focus primarily on control methods that are cheap, effective, sustainable and readily disseminated, such as host-plant resistance and biological control. A framework based on the application of force multipliers is proposed as a means of prioritising elements of future Bemisia control strategies for cassava in Africa. PMID:24706604

  13. Phylogenetic analysis of three species of Encarsia ( Hymenoptera: Aphelinidae) parasitizing Bemisia tabaci ( Hemiptera: Aleyrodidae) in China based on their 28S rRNA gene%中国寄生烟粉虱的三种恩角蚜小蜂28S rRNA系统发育分析

    Institute of Scientific and Technical Information of China (English)

    薛夏; 彭伟录; Muhammad Z. AHMED; Nasser S. MANDOUR; 任顺祥; Andrew G. S. CUTHBERTSON; 邱宝利

    2012-01-01

    Encarsia F(o)rster consists of important parasitoids of whitefly (Bemisia tabaci) pests,including E.bimaculata,E.formosa and E.sophia,the three most important aphelinid parasitoids in China.Eight populations of Encarsia from the South,Southeast,North and Southwest of China,as well as two populations from Malaysia and Egypt,respectively,were collected in the present study,and their interspecies phylogenetic relationships were analyzed based on 28S rRNA D2 and D3 expansion regions.The D2 and D3 regions were consistent with each other,confirmed a closer genetic relationship between E.sophia and E.bimaculata since they both belong to the Encarisa strenus species group,compared to those between these two species and En.formosa.Results of the genetic distance analysis using 28S rRNA D2 sequences revealed that there are certain genetic divergences within single species of the Encarsia parasitoids.The Guangzhou population of Encarsia sophia is more close to populations from Australia,Spain,Egypt and Ethiopia,but further from the population from Thailand.E. bimaculata populations from Sudan,Egypt and Guatemala as well as one population from Australia cluster together,while E.formosa Hengshui and Kunming populations cluster together with those from USA,UK and Greece,but are further from the Egypt population.The reasons for the inconsistency between the genetic and geographical distances of the Encarsia species are discussed.%蚜小蜂Bemisia tabaci是烟粉虱的重要天敌,其中双斑恩蚜小蜂Encarsia bimaculata,丽蚜小蜂E.forTmosa以及浅黄恩蚜小蜂E.sophia是国内烟粉虱寄生蜂3个优势种.本研究以采自中国华南、华东、华北、西南地区以及马来西亚、埃及的E.bimaculata、E.formosa和E.sophia3个优势种的8个不同地理种群为研究对象,对其28SrRNA D2和D3扩展区序列进行了测定和分析.结果表明:Encarsia属的恩蚜小蜂其28S rRNA D2和D3序列在种间水平上高度保守;与丽蚜小蜂相比,双斑

  14. Caracterização molecular da mosca-branca (Bemisia spp.) no Brasil Molecular characterization of whitefly (Bemisia spp.) in Brazil

    OpenAIRE

    MARIA REGINA VILARINHO DE OLIVEIRA; MYRIAN SILVANA TIGANO; SALAH ALJANABI

    2000-01-01

    A análise de RAPD foi utilizada para avaliar a variabilidade genética de 12 populações brasileiras de Bemisia spp. (Hemiptera: Aleyrodidae). Foram analisados dez primers que permitiram a detecção de polimorfismo entre as amostras testadas. Os resultados obtidos mostraram que os indivíduos analisados provenientes de uma colônia mantida desde 1983 apresentaram perfis de RAPD próximos do padrão de B. tabaci oriunda da Califórnia, EUA. As outras populações analisadas apresentaram padrões semelhan...

  15. Potential sources of whitefly (Hemiptera: Aleyrodidae) resistance in desert watermelon (Citrullus colocynthis) germplasm

    Science.gov (United States)

    Selection for host plant resistance and incorporation of natural resistance into cultivars is a fundamental strategy to control insects and diseases in an environmentally-sensitive manner, and may help reduce reliance on synthetic pesticides. The sweetpotato whitefly, Bemisia tabaci (Gennadius), is...

  16. Tritrophic interaction among host plants, whiteflies, and parasitoids

    Science.gov (United States)

    Laboratory experiments were conducted to compare effects of cotton, bean, sweet potato, and tomato on the mortality and development of Bemisia tabaci (Gennadius) biotype B, Traileurodes abutilonea (Haldeman), and T. vaporariorum (Westwood) and on the key biological parameters of an exotic parasitoid...

  17. Sweet Potato Leaf Curl Virus: Virus Reservoir in Species of Wild Morning Glory

    Science.gov (United States)

    Recent increases in populations of the Sweetpotato leaf curl virus (SPLCV) vector, the sweetpotato whitefly, Bemisia tabaci (Gennadius), led to a dramatic increase in the disease in sweetpotato (Ipomoea batatas). Knowledge of crop or weed species that occur in sweetpotato growing areas and can serv...

  18. 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...

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

    OpenAIRE

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

    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...

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    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)

  2. Expression Profiling in Bemisia tabaci under Insecticide Treatment: Indicating the Necessity for Custom Reference Gene Selection

    OpenAIRE

    Liang, Pei; Guo, Yajie; Zhou, Xuguo; Gao, Xiwu

    2014-01-01

    Finding a suitable reference gene is the key for qRT-PCR analysis. However, none of the reference gene discovered thus far can be utilized universally under various biotic and abiotic experimental conditions. In this study, we further examine the stability of candidate reference genes under a single abiotic factor, insecticide treatment. After being exposed to eight commercially available insecticides, which belong to five different classes, the expression profiles of eight housekeeping genes...

  3. Behavioral response of Bemisia tabaci (Hemiptera : Aleyrodidae) to 20 plant extracts

    OpenAIRE

    Emilie, D; Mallent, M.; Menut, C.; Chandre, Fabrice; Martin, T.

    2015-01-01

    In the Mediterranean region, the use of small-mesh netting to protect horticultural crops is an effective sustainable tool against pests. But in tropical regions, because of high humidity under the net favoring fungal development, netting with a larger mesh size has to be used, protecting crops against lepidopteran pests but not against small pests such as hemipterans, thrips, and phytophagous mites. A combination of netting with a repellent or irritant product is one possible solution, but t...

  4. Temperature stress, anti-oxidative enzyme activity and virus acquisition in Bemisia tabaci (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    In most eukaryotic systems, antioxidants provide protection when cells are exposed to stressful environmental conditions. Antioxidants, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase, function in a stepwise series with SOD initially preventing oxidative damage by conve...

  5. 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...

  6. Codon Usage Bias in Two Hemipteran Insect Species: Bemisia tabaci and Homalodisca coagulata

    OpenAIRE

    Jyotika Sharma; Supriyo Chakraborty; Arif Uddin

    2014-01-01

    Codon bias is the nonuniform use of synonymous codons which encode the same amino acid. Some codons are more frequently used than others in several organisms, particularly in the highly expressed genes. The spectacular diversity of insects makes them a suitable candidate for analyzing the codon usage bias. Recent expansion in genome sequencing of different insect species provides an opportunity for studying the codon usage bias. Several works on patterns of codon usage bias were done on Droso...

  7. Response of Bemisia tabaci (Hemiptera: Aleyrodidae) to vapor pressure deficit: Oviposition, immature survival and body size

    Science.gov (United States)

    Ambient temperature is an abiotic factor that has been studied extensively in insect biology and population dynamics while relatively little investigations have been carried out on the impact of ambient moisture. Whiteflies cause major agricultural problems in environments ranging from arid to humi...

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

    OpenAIRE

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

    2012-01-01

    In the last 20 years, molecular ecology approaches have proven to be extremely useful to identify and assess factors associated with viral emerging diseases, particularly in economically and socially important tropical crops such as maize (maize streak disease) and cassava (cassava mosaic disease). Molecular ecology approaches were applied in Reunion Island to analyze the epidemic of tomato yellow leaf curl disease, which has been affecting the island since the end of the 1990s. Before the in...

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

    OpenAIRE

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

    2015-01-01

    Our greenhouse tomatoes have suffered from attacks by viruliferous whiteflies Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) over the last 10 years. The fundamental countermeasure was the application of an electric field screen to the greenhouse windows to prevent their entry. However, while the protection was effective, it was incomplete, because of the lack of a guard at the greenhouse entrance area; in fact, the pests entered from the entrance door when workers entered and exited. To ...

  10. Bazı ilaçların laboratuvar koşullarında, tütün beyazsineği parazitoiti Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae)’a karşı yan etkileri

    OpenAIRE

    Mustafa PORTAKALDALI; Serdar SATAR

    2015-01-01

    The silverleaf whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of major pests in greenhouses vegetable cultivation. Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) has an important role among effective parasitoids used in biological control of the silverleaf whitefly. Nondestructive or less destructive pesticides against this parasitoid should be preferred in the scope of biological control. For this goal, side effects of 8 plant protection products, including spinos...

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

    Science.gov (United States)

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

    2014-01-01

    The western flower thrips, Frankliniella occidentalis (Pergande), and the sweetpotato whitefly, Bemisia tabaci (Gennadius), are both invasive insect pests and are present in most of the same agricultural crops without a clear dominance of either species. Here, intra- and interspecific competition in B. tabaci and F. occidentalis was determined under controlled experiments. The results showed that intraspecific competition was distinct in F. occidentalis and that the co-occurrence of B. tabaci had a strong effect on F. occidentalis, resulting in a decrease in oviposition. Significant intraspecific competition was found in B. tabaci, and the coexistence of F. occidentalis had limited effect on the oviposition of B. tabaci. In a selective host plant preference experiment, both F. occidentalis and B. tabaci preferred eggplants most, followed by cucumbers and tomatoes. On cucumber plants, B. tabaci was predominant, whereas on eggplant and tomato plants, F. occidentalis and B. tabaci exhibited comparative competitive abilities during the initial stage. However, over time, higher numbers of B. tabaci than that of F. occidentalis were found on the two host plants. Our in vitro and potted plant experiments indicate that B. tabaci is competitively superior to F. occidentalis, which might help to explain their differential distribution patterns in China. PMID:25480973

  12. Evolution and homoplasy at the Bem6 microsatellite locus in three sweetpotato whitefly (Bemisia tabaci) cryptic species

    Science.gov (United States)

    The evolution of individual microsatellite loci is often complex and homoplasy is common but often goes undetected. Sequencing alleles at a microsatellite locus can provide a more complete picture of the common evolutionary mechanisms occurring at that locus and can reveal cases of homoplasy. Within...

  13. First report of Bemisia tabaci biotype Q in Costa Rica and detection of viruliferous whiteflies in greenhouses

    Science.gov (United States)

    Whiteflies are a complex that comprises multiple species and biotypes or races which are capable of affecting crops by phloem feeding, virus transmission and promotion of fungal colonization. The distribution of these pests is worldwide. In Costa Rica, a country located in the tropics, the most prob...

  14. Inoculation of tomato plants with rhizobacteria enhances the performance of the phloem-feeding insect Bemisia tabaci

    OpenAIRE

    Shavit, Roee; Ofek-Lalzar, Maya; Burdman, Saul; Morin, Shai

    2013-01-01

    In their natural environment, plants experience multiple biotic interactions and respond to this complexity in an integrated manner. Therefore, plant responses to herbivory are flexible and depend on the context and complexity in which they occur. For example, plant growth promoting rhizobacteria (PGPR) can enhance plant growth and induce resistance against microbial pathogens and herbivorous insects by a phenomenon termed induced systemic resistance (ISR). In the present study, we investigat...

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

    DEFF Research Database (Denmark)

    Sohrabi, Fariba; Enkegaard, Annie; Shishehbor, Parviz; Saber, Moosa; Mosaddegh, Mohammad Said

    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 by...... 5th instar nymphs and adults of O. majusculus offered unparasitised 3rd, early 4th or 4th instar B. tabaci nymphs or parasitised nymphs containing 2nd or 3rd larval instar or pupal parasitoids. In addition, prey preference of the two stages of O. majusculus for parasitised or unparasitised whitefly...... nymphs was studied using nine different prey combinations. Both predator stages readily preyed upon on both unparasitised and parasitised B. tabaci. In no-choice experiments, predation on 3rd instar E. formosa by adult predators was the highest, while predator nymphs preyed most on unparasitised 3rd...

  16. Speciation in Thrips tabaci Lindeman, 1889 (Thysanoptera: the current state of knowledge and its consequences*

    Directory of Open Access Journals (Sweden)

    Fail József

    2016-03-01

    Full Text Available Based on DNA sequences of the mitochondrial COI gene, Thrips tabaci has been divided into three lineages: a tobacco-associated (T and two leek-associated types (L1, L2. It is believed that the arrhenotokous leek-associated type (L1 is the ancient form of T. tabaci and that the T type diverged from it and adapted to solanaceous host plants. The third lineage of T. tabaci, the so-called thelytokous leek-associated type (L2 and the L1 form share many host plants. According to a recent study, the L2 form of T. tabaci could outcompete the L1 type on cabbage plants; it might therefore be more accurate to identify it as the thelytokous cabbage-associated type.

  17. Hubungan Morfologi Tanaman Tomat dengan Preferensi Bemicia tabaci sebagai Bentuk Ketahanan Pasif terhadap Virus Kuning

    OpenAIRE

    Gunaeni, Neni; Gaswanto, Redy; Srie Duriat, Ati

    2011-01-01

    The purpose of the study was to determine the preference of Bemicia tabaci to tomato plants with different morphological characteristics as a passive resistance mechanism of the plant against tomato yellow leaf curl virus (TYLCV) transmitted by the insect. The study was conducted in the Vegetable Crops Research Institute, Lembang, West Java, Indonesia (1,200 m above sea level) from June to December 2006. About 400 individuals of B. tabaci were released in the center point of a 1-m...

  18. Trap catches of the sweetpotato whitefly (Homoptera: Aleyrodidae) in the Imperial Valley, California, from 1996 to 2002

    Institute of Scientific and Technical Information of China (English)

    CHANG-CHI CHU; EDWARD BARNES; ERIC T. NATWICK; TIAN-YE CHEN; DAVID RITTER; THOMAS J. HENNEBERRY

    2007-01-01

    An outbreak of the sweetpotato whitefly, Bemisia tabaci (Gennadius), biotype B occurred in the Imperial Valley, California in 1991. The insects destroyed melon crops and seriously damaged other vegetables, ornamentals and row crops. As a result of the need for sampling technology, we developed a whitefly trap (named the CC trap) that could be left in the field for extended time periods. We used the traps to monitor populations of B. tabaci adults during year-round samplings from 1996 to 2002 to study variations in the weekly trap catches of the insect. The greatest number of B. tabaci adults was recorded in 1996, followed by a continuing annual decrease in trap catches each year through 2002. The overall decline of B. tabaci is attributed in part to the adoption of an integrated pest management (IPM) program initiated in 1992 and reduced melon hectares from 1996 to 2002. Other factors may also have contributed to the population reductions. Seasonally, B. tabaci trap catches decreased during the late summer and fall concurrent with decreasing minimum temperatures that are suggested to be a significant factor affecting seasonal activity and reproduction.

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

    Science.gov (United States)

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

    2016-01-01

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

  20. Reduction of viral load in whitefly (Bemisia tabaci Gen.) feeding on RNAi-mediated bean golden mosaic virus resistant transgenic bean plants.

    Science.gov (United States)

    de Paula, Nayhanne T; de Faria, Josias C; Aragão, Francisco J L

    2015-12-01

    The RNAi concept was explored to silence the rep gene from the bean golden mosaic virus (BGMV) and a genetically modified (GM) bean immune to the virus was previously generated. We investigated if BGMV-viruliferous whiteflies would reduce viral amount after feeding on GM plants. BGMV DNA amount was significantly reduced in whiteflies feeding in GM-plants (compared with insects feeding on non-GM plants) for a period of 4 and 8 days in 52% and 84% respectively. PMID:26297125

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

    NARCIS (Netherlands)

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

    2004-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Alexander M Muvea

    Full Text Available 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.

  3. Plant traits associated with resistance to Thrips tabaci in cabbage (Brassica oleracea var capitata)

    OpenAIRE

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

    2008-01-01

    Thrips tabaci is a major problem in the cultivation of cabbage for storage, as this pest causes symptoms that necessitate the removal of affected leaves from the product. Between cabbage varieties large differences in susceptibility occur. This study aimed to identify plant traits associated with these differences, in field experiments with natural infestation in 2005 and 2006. One factor affecting the amount of thrips damage was the timing of the development of the head. In an experiment wit...

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

    International Nuclear Information System (INIS)

    An extracellular toxin, tabtoxinine-β-lactam (TβL), is produced by Pseudomonas syringae pv. tabaci. This toxin irreversibly inhibits its target, glutamine synthetase; yet P. syringae pv. tabaci retains significant amounts of glutamine synthetase activity during toxin production in culture. As part of our investigation of the self-protection of P. syringae pv. tabaci, the authors compared the effects of TβL on Tox+ (TβL-producing, insensitive to TβL) and Tox- (TβL nonproducing, sensitive to TΛ) strains. The extent of protection afforded to the Tox- strain when induced to adenylylate glutamine synthetase was tested. It was concluded that an additional protection mechanism was required. A detoxification activity was found in the Tox+ strain which opens the ε-lactam ring to TβL to produce the inactive, open-chain form, tabtoxinine. Whole cells of the Tox+ strain incubated for 24 h with [14C]TβL (0.276 μmol/3 x 1010 cells) contained [14C]tabtoxinine (0.056 μmol), and the medium contained TβL (0.226 μmol). Extracts of spheroplasts of the Tox+ stain also converted TβL to tabtoxinine, whereas extracts of the Tox- strain did not alter TβL. The conversion was time dependent and stoichiometric and was destroyed by boiling for 30 min or by the addition of 5mM EDTA. Penicillin, a possible substrate and competitive inhibitor of this lactamase activity, inhibited the conversion of TΛ to tabtoxinine. Periplasmic fluid did not catalyze the conversion of TβL

  5. Relative susceptibility of onion (allium cepa) genotypes of pakistan to onion thrips (thrips tabaci) (thysanoptera: thripidae)

    International Nuclear Information System (INIS)

    The present studies were conducted during 2008-2010, to test the susceptibility of onion crop to a globally recognized pest of onion Thrips tabaci Lindeman. The results revealed that genotype VRIO-3 was highly susceptible one having 181.7 thrips per plant. The genotype Desi Large was moderately resistant having 94.2 thrips per plant. Survey of susceptibility of onion cultivars revealed that there is a scarcity of thrips resistant varieties in agro-ecosystem of Punjab, Pakistan. So, thrips resistant varieties must be developed to combat the menace to thrips attack. This study provides a guideline to the genetic engineers and conventional breeders. (author)

  6. Entomopathogenic fungi against whiteflies. Tritrophic interactions between Aschersonia species, Trialeurodes vaporariorum and Bemisia argentifolii, and glasshouse crops

    NARCIS (Netherlands)

    Meekes, E.T.M.

    2001-01-01

    Many horticultural and agricultural crops are good host plants for the greenhouse whitefly, Trialeurodes vaporariorum, and the silverleaf whitefly, Bemisia argentifolii . Their damage to crops is manifold. When present in sufficient numbers they can cause leaf drop and inhibit fruit maturation. They

  7. 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 cen

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

    International Nuclear Information System (INIS)

    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. Onion Thrips, Thrips tabaci, Have Gut Bacteria That are Closely Related to the Symbionts of the Western Flower Thrips, Frankliniella occidentalis

    OpenAIRE

    Vries, de, P.M.; Wurff, van der, A.W.G.; Jacobs, G.; Breeuwer, J.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 desc...

  10. 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. PMID:24548212

  11. CONTROLE QUÍMICO DA MOSCA BRANCA Bemisia argentifolli SOBRE A BERINJELA CHEMICAL CONTROL OF THE WHITE FLY Bemisia argentifolli ON EGGPLANT

    Directory of Open Access Journals (Sweden)

    Selby Pereira dos Santos

    2007-09-01

    Full Text Available

    Avaliou-se a eficiência de três dosagens do inseticida fisiológico HIT 98 e uma dose NNI-750D-SC, comparado ao Evolution e Actara, no controle da mosca branca Bemisia argentifolli sobre berinjela. O experimento foi conduzido no Departamento de Horticultura da Escola de Agronomia da Universidade Federal de Goiás, no período de abril a julho de 1999. Foi utilizado um delineamento em blocos completamente ao acaso com cinco tratamentos e quatro repetições. Os tratamentos aplicados foram os seguintes: 1 NNI-750D-SC na dosagem de 100 ml/ 100 litros de água; 2 HIT 98 nas dosagens de 10, 15 e 20 g/100 litros de água; 3 Evolution 970 PL na dosagem de 75 g/ 100 litros; 4 Actara na dosagem de 15 g/ l00 litros de água e 5 testemunha. Os resultados obtidos mostraram que, com exceção do Evolution, os outros tratamentos controlaram a citada praga até 17 dias após a aplicação, com eficiências que variaram de 85 a 96% de controle.

    PALAVRAS-CHAVE: Insecta; inseticidas; Bemisia sp.; berinjela.

    The efficiency of three dosages of the physiologic insecticide was evaluated. Hit 98 and a dose of NNI-750 D

  12. Impact of cotton planting date and nitrogen fertilization on Bemisia argentifolii populations

    Institute of Scientific and Technical Information of China (English)

    JIAN-LONGBI; DONG-MEILIN; KEH-SHENLII; NICKC.TOSCANO

    2005-01-01

    The silverleaf whitefly (Bemisia argentifolii Bellows and Perring) is a widely distributed pest of cotton (Gossypium hirsutum L.) and the population levels may be affected by rates of nitrogen fertilization and planting date. Field experiments were conducted to investigate the impact of cotton planting date and nitrogen fertilization on silverleaf whitefly population dynamics. Cotton was planted on 26 April and 8 June, for the early and late plantings, respectively. Nitrogen treatments consisted of soil applications of 0, 112, 168 and 224 kg of nitrogen per hectare. The population levels of adult whiteflies were much higher on early-planted cotton than on late planting. Also, increased numbers of adult whiteflies on both early and late plantings occurred with increasing amounts of applied nitrogen.Applied nitrogen increased seed cotton yields of early plantings but had no effect on the yields of late plantings.

  13. Isolation and identification of culturable forms of bacteria from the sweet potato whitefly Bemesia tabaci Genn. (Homoptera: Aleyrodidae) in Jordan

    OpenAIRE

    ATEYYAT, Mazen Ahmad; SHATNAWI, Mohamad; AL-MAZRA'AWI, Mohammad

    2010-01-01

    Homopteran insects contain bacteria in their cells and tissues known as "secondary symbionts," which under special environmental circumstances act against their host insects. In this study, both molecular- and culture-based methods were used to characterize the bacteria associated with the whitefly in Jordan. We isolated, cultured, and identified 11 species of bacteria from nymphs (6 species), adults (8 species), and parasitized pupae (2 species) of the whitefly Bemesia tabaci colle...

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

    Directory of Open Access Journals (Sweden)

    Nézio Nery de Andrade Filho

    2010-08-01

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

  15. Potencial biótico da mosca-branca Bemisia argentifolii a diferentes plantas hospedeiras Biotic potential of Bemisia argentifolii to different host plants

    Directory of Open Access Journals (Sweden)

    Geni L. Villas Bôas

    2002-03-01

    Full Text Available A mosca-branca Bemisia argentifolii Bellows & Perring, 1994 causa danos em diversas culturas de importância econ��mica no Brasil. Este trabalho teve o objetivo de avaliar o potencial biótico do inseto nas plantas de abobrinha, feijão, mandioca, milho, poinsétia, repolho e tomate. Os experimentos foram conduzidos na Embrapa Hortaliças, em Brasília-DF, em câmaras climatizadas, à temperatura de 28 ± 2ºC e casa de vegetação, à temperatura ambiente (25 ± 8ºC, partindo-se de uma população de B. argentifolii, criada em poinsétia desde 1995. Repolho e feijão foram as plantas hospedeiras que apresentaram períodos pré-imaginais mais curtos, respectivamente 20,5 e 21,9 dias. As maiores porcentagens de mortalidade nesses períodos foram observadas em mandioca (97,9% e milho (94,2%. A razão sexual em geral foi favorável às fêmeas. O inseto apresentou valores muito próximos de r m (capacidade intrínseca de crescimento da população, variando de 0,18 em feijão a 0,13 em repolho, mostrando estar igualmente adaptado a estes hospedeiros. Resultados diversos foram observados em milho e mandioca, onde as fêmeas apresentaram alta mortalidade (> 90%, o que sugere baixa capacidade de utilização destes hospedeiros pela mosca-branca.The whitefly Bemisia argentifolii Bellows & Perring, 1994 has been causing damage in several economically important crops in Brazil. The purpose of this research was to determine the biotic potential of the insect in zucchini, dry bean, cassava, corn, poinsettia, cabbage and tomato. The experiments were carried out at the Experimental Station of Embrapa Hortaliças, located in Brasilia, in BOD chamber (28°C ± 2°C and greenhouse (25°C ± 8°C, with a whitefly population continuously reared on poinsettia plants since 1995. Cabbage and dry bean were the host plants with shorter pre-imaginal periods, 20.5 and 21.9 days respectively. The highest mortality in this periods was observed in cassava (97.9% and

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

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    M. F. Mahmoud

    2013-09-01

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

  17. Evaluating Weeds as Hosts of Tomato yellow leaf curl virus.

    Science.gov (United States)

    Smith, Hugh A; Seijo, Teresa E; Vallad, Gary E; Peres, Natalia A; Druffel, Keri L

    2015-08-01

    Bemisia tabaci (Gennadius) biotype B transmits Tomato yellow leaf curl virus (TYLCV), which affects tomato production globally. Prompt destruction of virus reservoirs is a key component of virus management. Identification of weed hosts of TYLCV will be useful for reducing such reservoirs. The status of weeds as alternate hosts of TYLCV in Florida remains unclear. In greenhouse studies, B. tabaci adults from a colony reared on TYLCV-infected tomato were established in cages containing one of four weeds common to horticultural fields in central and south Florida. Cages containing tomato and cotton were also infested with viruliferous whiteflies as a positive control and negative control, respectively. Whitefly adults and plant tissue were tested periodically over 10 wk for the presence of TYLCV using PCR. After 10 wk, virus-susceptible tomato plants were placed in each cage to determine if whiteflies descended from the original adults were still infective. Results indicate that Bidens alba, Emilia fosbergii, and Raphanus raphanistrum are not hosts of TYLCV, and that Amaranthus retroflexus is a host. PMID:26314055

  18. BIOEFFICACY OF CYANTRANILIPROLE 10% OD-AN ANTHRANILIC DIAMIDE INSECTICIDE AGAINST SUCKING PESTS OF COTTON

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    R. D. PATEL

    2014-03-01

    Full Text Available Field studies were conducted during two consecutive kharif seasons of 2010-11 and 2011-12 in order to evaluate the field bio-efficacy of a newer molecule cyantraniliprole 10% OD (Cyazypyr @ 45, 60, 75, 90 and 105 g a.i./ ha along with indoxacarb 14.5 SC (Avaunt @ 75 g a.i./ha and endosulfan 35 EC (Thiodan @ 350 g a.i./ha as standard checks against the cotton aphid, Aphis gossypii Glover; thrips, Thrips tabaci Lindeman and whitefly, Bemisia tabaci (Gennadius. The two higher doses of cyantraniliprole 10% OD i.e. 90 and 105 g a.i./ha was found highly effective in managing the population of aphid, thrips and whitefly during both the year compared to endosulfan and indoxacarb. The seed cotton yield was recorded significantly higher in treatments cyantraniliprole 10% OD @ 90 (31.97 q/ha and 105 (33.33 q/ha g a.i./ha with an increase of 50.80 and 52.81 per cent over untreated control, respectively. Considering the bio-efficacy and yield, cyantraniliprole 10% OD @ 90 g a.i./ha is recommended for effective control of sucking pests in cotton ecosystem.

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

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    Kontsedalov Svetlana

    2010-05-01

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

  20. Efectos letales y subletales de insecticidas sobre Bemisia tabaci y su principal parasitoide Eretmocerus mundus e impacto sobre aspectos comportamentales del mismo

    OpenAIRE

    Francesena, Natalia

    2015-01-01

    El control biológico de plagas mediante enemigos naturales (parasitoides, depredadores y entomopatógenos) es una de las estrategias de control que promueve en sus premisas el Manejo Integrado de Plagas (MIP). En los últimos años ha habido un incremento sobre la importancia económica de estos enemigos en la agricultura y de las restricciones de los métodos tradicionales de control a través del uso de plaguicidas. En este sentido, el empleo de enemigos naturales para el control biológico de pla...

  1. Pathogenicity of Aschersonia spp. against whiteflies Bemisia argentifolii and Trialeurodes vaporariorum.

    Science.gov (United States)

    Meekes, Ellis T M; Fransen, Joanne J; van Lenteren, Joop C

    2002-09-01

    Entomopathogenic fungi of the genus Aschersonia are specific for whitefly and scale insects. They can be used as biological control agents against silverleaf whitefly, Bemisia argentifolii and greenhouse whitefly, Trialeurodes vaporariorum. Forty-four isolates of Aschersonia spp. were tested for their ability to sporulate and germinate on semi-artificial media and to infect insect hosts. Seven isolates sporulated poorly (less than 1x10(7) conidia/dry weight) and 10 were not able to infect either of the whitefly species. Several isolates were able to produce capilliconidia. Infection level was not correlated with germination on water agar. After a selection based on spore production and infection, virulence of 31 isolates was evaluated on third instar nymphs of both whitefly species on poinsettia (Euphorbia pulcherrima). Whitefly infection levels varied between 2 and 70%, and infection percentages of B. argentifolii correlated with that of T. vaporariorum. However, mortality was higher for T. vaporariorum than for B. argentifolii, as a result of a higher 'mortality due to unknown causes.' Several isolates, among which unidentified species of Aschersonia originating from Thailand and Malaysia, A. aleyrodis from Colombia, and A. placenta from India showed high spore production on semi-artificial medium and high infection levels of both whitefly species. PMID:12417207

  2. Nonpreference of whitefly for oviposition in tomato genotypes Não-preferência para oviposição de mosca-branca por genótipos de tomateiro

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    Luciana Cláudia Toscano

    2002-12-01

    Full Text Available The silverleaf whitefly is one of most important pests of tomato (Lycopersicon spp.. The use of host plant resistance to control this insect is an interesting, potentially useful technique, but in demand of more research. The objectives of this work were to evaluate the oviposition non-preference of Bemisia tabaci (Gennadius, 1889 biotype B for different tomato plant genotypes, evaluating the correlation between oviposition preference and pubescence in the genotypes, and analyzing the abaxial and adaxial surfaces of Lycopersicon pennellii leaflets under the scanning electron microscope. Four wild tomato genotypes, LA 716 (L. pennellii; PI 127826 and PI 127827 (L. hirsutum; PI 134417 (L. hirsutum f. glabratum, and two commercial genotypes, Santa Clara and Bruna VFN hybrid (L. esculentum were evaluated for number of eggs cm-2 in free and no-choice oviposition tests, using randomized block design and completely randomized design, respectively. The number of trichome was measured in 4 mm² and coefficients of correlation between number of trichomes and number of eggs were calculated. The wild genotypes LA 716 and PI 134417 were less preferred showing oviposition nonpreference resistance type in both tests. The Bruna VFN and Santa Clara were more preferred in free-choice test, while wild genotypes PI 127826 and PI 127827 were more preferred in no-choice test. L. pennellii leaflets presented glandular trichomes type IV in both surfaces. Santa Clara genotype presented higher density of trichomes, and B. tabaci biotype B presented higher preference to oviposition.A mosca-branca Bemisia tabaci (Gennadius, 1889 biótipo B é atualmente uma das principais pragas do tomateiro (Lycopersicon spp.. O uso de plantas resistentes para o controle deste inseto apresenta-se interessante, com grande potencial para Manejo Integrado de Pragas. Este trabalho teve por objetivos verificar a não-preferência para oviposição de B. tabaci biótipo B em genótipos de

  3. Toxicity of oil from Anacardium humile Saint Hill (Anacardiaceae), on Bemisia tuberculata (Bondar, 1923) (Hemipttera: Aleyrodidae) on cassava plants.

    OpenAIRE

    Andrade Filho, Nézio Neri; Roel, Antonia Railda; Yano, Mami; Cardoso, Claudia Andreia Lima; Matias, Rosemary

    2013-01-01

    The aim was to evaluate the toxic effects of essential oil of Anacardium humile, in different concentrations, on survival and development of the whitefly Bemisia tuberculata on the cassava plants, Manihot esculenta Crantz. The experiment was carried out in a greenhouse at a temperature of 26±4º C. Twenty adults were confined in cages, which contained a leaf of cassava plant and removed after 24 hours. The oil was sprayed in the concentrations of the 0.006%, 0.05%, 0.8% and 2%, when the nymphs...

  4. Preference and prey switching in a generalist predator attacking local and invasive alien pests.

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    Coline C Jaworski

    Full Text Available Invasive pest species may strongly affect biotic interactions in agro-ecosystems. The ability of generalist predators to prey on new invasive pests may result in drastic changes in the population dynamics of local pest species owing to predator-mediated indirect interactions among prey. On a short time scale, the nature and strength of such indirect interactions depend largely on preferences between prey and on predator behavior patterns. Under laboratory conditions we evaluated the prey preference of the generalist predator Macrolophus pygmaeus Rambur (Heteroptera: Miridae when it encounters simultaneously the local tomato pest Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae and the invasive alien pest Tuta absoluta (Meyrick (Lepidoptera: Gelechiidae. We tested various ratios of local vs. alien prey numbers, measuring switching by the predator from one prey to the other, and assessing what conditions (e.g. prey species abundance and prey development stage may favor such prey switching. The total predation activity of M. pygmaeus was affected by the presence of T. absoluta in the prey complex with an opposite effect when comparing adult and juvenile predators. The predator showed similar preference toward T. absoluta eggs and B. tabaci nymphs, but T. absoluta larvae were clearly less attacked. However, prey preference strongly depended on prey relative abundance with a disproportionately high predation on the most abundant prey and disproportionately low predation on the rarest prey. Together with the findings of a recent companion study (Bompard et al. 2013, Population Ecology, the insight obtained on M. pygmaeus prey switching may be useful for Integrated Pest Management in tomato crops, notably for optimal simultaneous management of B. tabaci and T. absoluta, which very frequently co-occur on tomato.

  5. Preference and prey switching in a generalist predator attacking local and invasive alien pests.

    Science.gov (United States)

    Jaworski, Coline C; Bompard, Anaïs; Genies, Laure; Amiens-Desneux, Edwige; Desneux, Nicolas

    2013-01-01

    Invasive pest species may strongly affect biotic interactions in agro-ecosystems. The ability of generalist predators to prey on new invasive pests may result in drastic changes in the population dynamics of local pest species owing to predator-mediated indirect interactions among prey. On a short time scale, the nature and strength of such indirect interactions depend largely on preferences between prey and on predator behavior patterns. Under laboratory conditions we evaluated the prey preference of the generalist predator Macrolophus pygmaeus Rambur (Heteroptera: Miridae) when it encounters simultaneously the local tomato pest Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and the invasive alien pest Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). We tested various ratios of local vs. alien prey numbers, measuring switching by the predator from one prey to the other, and assessing what conditions (e.g. prey species abundance and prey development stage) may favor such prey switching. The total predation activity of M. pygmaeus was affected by the presence of T. absoluta in the prey complex with an opposite effect when comparing adult and juvenile predators. The predator showed similar preference toward T. absoluta eggs and B. tabaci nymphs, but T. absoluta larvae were clearly less attacked. However, prey preference strongly depended on prey relative abundance with a disproportionately high predation on the most abundant prey and disproportionately low predation on the rarest prey. Together with the findings of a recent companion study (Bompard et al. 2013, Population Ecology), the insight obtained on M. pygmaeus prey switching may be useful for Integrated Pest Management in tomato crops, notably for optimal simultaneous management of B. tabaci and T. absoluta, which very frequently co-occur on tomato. PMID:24312646

  6. Life history and life table analysis of the whitefly predator Delphastus catalinae (Coleoptera: Coccinellidae) on collards

    Institute of Scientific and Technical Information of China (English)

    TONG-XIANLIU

    2005-01-01

    The ladybeetle, Delphastus catalinae (Horn), is one of the most commonly used predacious natural enemies being commercially reared for controlling whiteflies, including Bemisia tabaci (Gennadius) biotype B (= B. argentifolii Bellows & Perring), on various ornamental and vegetable crops under greenhouse conditions. The development, survivorship,and fecundity of D. catalinae feeding on B. tabaci biotype B on collard plants were determined in the laboratory, and the age-specific life table parameters were analyzed based on the life history data. Developmental time was 4.0, 1.9, 1.1, 1.4, 5.2, and 5.3 days for eggs,first, second, third, fourth instars, and pupae, respectively, with an average of 18.9 days from oviposition to adult emergence for both sexes, 19.0 days for females, and 18.8 days for males.Adult longevities averaged 146.6 days for both sexes, 122.6 days for females, and 170.5 days for males. After an average 4.9 days preoviposition period, females laid a mean of 5.6 eggs per day over a 97.0-day period. Net reproductive rate (R0) and gross reproductive rate (Σmx) were estimated by life table analysis at 276.8 and 325.1, respectively. Generation time (T) and doubling time (DT) were 35.6 and 4.8 days respectively, and the intrinsic rate of natural population increase (rm) was estimated at 0.158, or l = 1.171 for the finite rate of increase.The rm value ofD. catalinae is similar to or higher than those of the whitefly feeding on most vegetable and ornamental crops, indicating that the ladybeetle is capable of regulating populations of B. tabaci biotype B and other whiteflies under greenhouse conditions.

  7. Spatiotemporal distribution of Macrolophus caliginosus in protected tomato crop (Heteroptera : Miridae)

    OpenAIRE

    Bonato, Olivier; Deschamps, C; Hamdi, F.; Ridray, G.; Chadoeuf, J.

    2011-01-01

    The characteristics of the generalist predator Macrolophus caliginosus made it the main actor in the biological control of Trialeurodes vaporariorum in protected tomato crops; but its action on Bemisia tabaci remains unclear. Because B tabaci does not belong to the natural host spectrum of M caliginosus, the feeding foraging behaviour of the predator is questioned when B tabaci is the only prey available. The movements of M caliginosus and its aggregation on B tabaci populations were studied ...

  8. A complete mitochondrial DNA genome derived from a Chinese population of the Bemisia afer species complex (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Wang, Hua-Ling; Zhang, Zhen; Bing, Xiao-Li; Liu, Yin-Quan; Liu, Shu-Sheng; Wang, Xiao-Wei

    2016-09-01

    We report here the sequence of a complete mitochondrial genome (mitogenome) of a population of Bemisia afer species complex, which was collected from Abutilonaviecnnae gaerner at LinYi, Shan Dong province of China (hereafter B. afer_China_Ag) (GenBank accession number: KR819174). The mitogenome of B. afer_China_Ag is 15 300 bp and contains 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and 2 control regions. The content and arrangement of mitochondrial genes of B. afer_China_Ag exhibit remarkable differences from the mitogenome of a B. afer population collected from African cassava (KF734668). Phylogenetic analyses based on 13 protein-coding genes support the close relationship of the two sequenced B. afer mitogenomes and confirm the species status of our specimen. PMID:26218308

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

    Directory of Open Access Journals (Sweden)

    Paulo Antonio de Souza Gonçalves

    2004-08-01

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

  10. Whitefly resistance in tomato: from accessions to mechanisms

    OpenAIRE

    Lucatti, A.F.

    2014-01-01

    Tomato (Solanum lycopersicum) is affected by a wide range of biotic stresses, of which Bemisia tabaci is one of the most important.Bemisia tabaci affects tomato directly through phloem sap feeding, and indirectly through its ability to be the vector of a large number of viruses. Different methods are available for whitefly control, and although several biological control agents are used against whiteflies in greenhouse cultivation, chemical control still is an essential component in open fiel...

  11. VIRUS-VECTOR INTERACTION AT DISEASE OF Tomato yellow leaf curl begomovirus-TYLCV

    OpenAIRE

    TOPAKÇI, Nurdan; GÜNEŞ, Sema

    2006-01-01

    The importance of the sweetpotato or tobacco whitefly, Bemisia tabaci (Genn.), as a serious pest in vegetable and cotton has increased woldwide. The whitefly reduced crop prodection by vectoring numerous plant viruses and by direct feedind damage. Tomato Yellow Leaf Curl Virus (TYLCV) is one of the most devastating begomoviruses of cultivated tomatoes in tropical and subtropical regions. TYLCV, is transmitted by the whitefly Bemisia tabaci in a circulative, persistent manner.

  12. Assessing transmission of crop diseases by insect vectors in a landscape context.

    Science.gov (United States)

    Carrière, Y; Degain, B; Hartfield, K A; Nolte, K D; Marsh, S E; Ellers-Kirk, C; Van Leeuwen, W J D; Liesner, L; Dutilleul, P; Palumbo, J C

    2014-02-01

    Theory indicates that landscape composition affects transmission of vector-borne crop diseases, but few empirical studies have investigated how landscape composition affects plant disease epidemiology. Since 2006, Bemisia tabaci (Gennadius) has vectored the cucurbit yellow stunting disorder virus (CYSDV) to cantaloupe and honeydew melons (Cucumis melo L.) in the southwestern United States and northern Mexico, causing significant reductions in yield of fall melons and increased use of insecticides. Here, we show that a landscape-based approach allowing simultaneous assessment of impacts of local (i.e., planting date) and regional (i.e., landscape composition) factors provides valuable insights on how to reduce crop disease risks. Specifically, we found that planting fall melon fields early in the growing season, eliminating plants germinating from seeds produced by spring melons after harvest, and planting fall melon fields away from cotton and spring melon fields may significantly reduce the incidence of CYSDV infection in fall melons. Because the largest scale of significance of the positive association between abundance of cotton and spring melon fields and CYSDV incidence was 1,750 and 3,000 m, respectively, reducing areas of cotton and spring melon fields within these distances from fall melon fields may decrease CYSDV incidence. Our results indicate that landscape-based studies will be fruitful to alleviate limitations imposed on crop production by vector-borne diseases. PMID:24665679

  13. Are Mummies and Adults of Eretmocerus mundus (Hymenoptera: Aphelinidae) Compatible With Modern Insecticides?

    Science.gov (United States)

    Fernández, María Del Mar; Medina, Pilar; Fereres, Alberto; Smagghe, Guy; Viñuela, Elisa

    2015-10-01

    The parasitic wasp Eretmocerus mundus (Mercet) is an important natural enemy of the widespread key pest Bemisia tabaci (Gennadius). The toxicity of 11 modern insecticides applied at their maximum field recommended rate in Spain was tested in two life stages of E. mundus: adults and mummies. Laboratory and persistence tests were conducted and effects assessed not only in terms of mortality but on reproductive performance as well. Some insecticides caused the same effect to both life stages: flubendiamide, methoxyfenozide, spiromesifen, and flonicamid were harmless, while spinosad and sulfoxaflor were harmful. The last two insecticides cannot be used jointly with E. mundus under any condition because they were highly persistent. The rest of tested insecticides (spirotetramat, metaflumizone, deltamethrin, abamectin, and emamectin) caused some direct mortality to one or both life stages and/or affected reproduction of the parasitic wasp and their harmful effect in the field ranged from short lived (metaflumizone and spirotetramat) to slightly persistent (emamectin) and to moderately persistent (abamectin and deltamethrin). Therefore, they could be recommended for use in integrated pest management programs together with the natural enemy if appropriate safety intervals after insecticide application are observed. PMID:26453715

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Functional response, host stage preference and interference of two whitefly parasitoids.

    Science.gov (United States)

    Xu, Hai-Yun; Yang, Nian-Wan; Duan, Min; Wan, Fang-Hao

    2016-02-01

    The functional responses of two parasitoids, Eretmocerus hayati Zolnerowich & Rose and Encarsia sophia Girault & Dodd, of whitefly Bemisia tabaci Gennadius Middle East-Asia Minor 1 were studied under laboratory conditions. In addition, the influence of host density and host stage on the competitive interactions between the two parasitoids, and biological control effect on whitefly were evaluated. In the functional response study, adult parasitoids were tested individually, with a conspecific or heterospecific competitor. Both Er. hayati and En. sophia exhibited a type II response to increasing host density, whether a conspecific or heterospecific competitor was present or not. Difference of searching rates and handling times between treatments suggested interference interactions existed between two parasitoid species. In the host stage preference study, two parasitoid species were jointly tested. Er. hayati had a competitive advantage over En. sophia when provided young host instars (first and second instar), whereas no advantage was found on old host instars (third and fourth instar). The biological control effect of Er. hayati and En. sophia in different introductions varied with host density. However, the effect of host instar on host mortality was not significant. These findings provide information for the practice of biological control and give better insight into how parasitoid species may coexist in diverse environments. PMID:25393924

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

    Directory of Open Access Journals (Sweden)

    Mustafa PORTAKALDALI

    2015-12-01

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

  17. Recessive Resistance Derived from Tomato cv. Tyking-Limits Drastically the Spread of Tomato Yellow Leaf Curl Virus

    Directory of Open Access Journals (Sweden)

    Rita C. Pereira-Carvalho

    2015-05-01

    Full Text Available The tomato yellow leaf curl disease (TYLCD causes severe damage to tomato (Solanum lycopersicum L. crops throughout tropical and subtropical regions of the world. TYLCD is associated with a complex of single-stranded circular DNA plant viruses of the genus Begomovirus (family Geminiviridae transmitted by the whitefy Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae. The tomato inbred line TX 468-RG is a source of monogenic recessive resistance to begomoviruses derived from the hybrid cv. Tyking F1. A detailed analysis of this germplasm source against tomato yellow leaf curl virus-Israel (TYLCV-IL, a widespread TYLCD-associated virus, showed a significant restriction to systemic virus accumulation even under continuous virus supply. The resistance was effective in limiting the onset of TYLCV-IL in tomato, as significantly lower primary spread of the virus occurred in resistant plants. Also, even if a limited number of resistant plants could result infected, they were less efficient virus sources for secondary spread owing to the impaired TYLCV-IL accumulation. Therefore, the incorporation of this resistance into breeding programs might help TYLCD management by drastically limiting TYLCV-IL spread.

  18. Recessive Resistance Derived from Tomato cv. Tyking-Limits Drastically the Spread of Tomato Yellow Leaf Curl Virus.

    Science.gov (United States)

    Pereira-Carvalho, Rita C; Díaz-Pendón, Juan A; Fonseca, Maria Esther N; Boiteux, Leonardo S; Fernández-Muñoz, Rafael; Moriones, Enrique; Resende, Renato O

    2015-05-01

    The tomato yellow leaf curl disease (TYLCD) causes severe damage to tomato (Solanum lycopersicum L.) crops throughout tropical and subtropical regions of the world. TYLCD is associated with a complex of single-stranded circular DNA plant viruses of the genus Begomovirus (family Geminiviridae) transmitted by the whitefy Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae). The tomato inbred line TX 468-RG is a source of monogenic recessive resistance to begomoviruses derived from the hybrid cv. Tyking F1. A detailed analysis of this germplasm source against tomato yellow leaf curl virus-Israel (TYLCV-IL), a widespread TYLCD-associated virus, showed a significant restriction to systemic virus accumulation even under continuous virus supply. The resistance was effective in limiting the onset of TYLCV-IL in tomato, as significantly lower primary spread of the virus occurred in resistant plants. Also, even if a limited number of resistant plants could result infected, they were less efficient virus sources for secondary spread owing to the impaired TYLCV-IL accumulation. Therefore, the incorporation of this resistance into breeding programs might help TYLCD management by drastically limiting TYLCV-IL spread. PMID:26008699

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

    Directory of Open Access Journals (Sweden)

    Yoshihiro Takikawa

    2015-05-01

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

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

    Science.gov (United States)

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

    2015-01-01

    Our greenhouse tomatoes have suffered from attacks by viruliferous whiteflies Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) over the last 10 years. The fundamental countermeasure was the application of an electric field screen to the greenhouse windows to prevent their entry. However, while the protection was effective, it was incomplete, because of the lack of a guard at the greenhouse entrance area; in fact, the pests entered from the entrance door when workers entered and exited. To address this, we developed a portable electrostatic insect sweeper as a supplementary technique to the screen. In this sweeper, eight insulated conductor wires (ICWs) were arranged at constant intervals along a polyvinylchloride (PVC) pipe and covered with a cylindrical stainless net. The ICWs and metal net were linked to a DC voltage generator (operated by 3-V alkaline batteries) inside the grip and oppositely electrified to generate an electric field between them. Whiteflies on the plants were attracted to the sweeper that was gently slid along the leaves. This apparatus was easy to operate on-site in a greenhouse and enabled capture of the whiteflies detected during the routine care of the tomato plants. Using this apparatus, we caught all whiteflies that invaded the non-guarded entrance door and minimized the appearance and spread of the viral disease in tomato plants in the greenhouse. PMID:26463195

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

    Directory of Open Access Journals (Sweden)

    Edson LL Baldin

    2007-12-01

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

  2. Nickel toxicity in Pseudomonas tabaci: single cell and bulk sample analysis of bacteria cultured at high cation levels

    International Nuclear Information System (INIS)

    The growth of Pseudomonas tabaci in nutrient medium is partially inhibited in the presence of 10-3 M added nickel (threshold toxic concentration), with complete inhibition at 10-2 M nickel - but no effect at 10sup-4 and 10-5 M. Toxic levels of nickel affect both cell division and cell viability. Spectrophotometric determination of intracellular levels of nickel at different external concentrations showed that the highest internal values occured with cells cultured in 10-4 M (non-toxic) nickel medium rather than in 10-3 (toxic) medium - suggesting that nickel toxicity does not primarily relate to internal concentration. X-ray microanalysis, carried out on whole bacterial cells, showed that toxic levels of nickel in the external medium resulted in a range of ionic changes in the cell, including a decrease in the level of K (K efflux) and an increase in the levels Mn, Fe, Ni, and Cu (transition metal cation influx). Other changes induced by nickel toxicity included an increase in the level of soluble S (with a decrease in insoluble S), an increased cell dry mass, and a conspicuous plasmolysis - which was observed both in whole and in ultrathin sections. The results obtained support a primary toxic effect of nickel at the cell surface - possibly directly affecting the transport activity of the plasmalemma. The resulting changes, particularly involving the influx of a range of cations, may lead to secondary toxic activities affecting the whole metabolism, leading to plasmolysis and inhibition of division. (Author)

  3. Tissue-specific changes of glutamine synthetase activity in oats after rhizosphere infestation by Pseudomonas syringae pv. tabaci. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Knight, T.J. [Univ. of Southern Maine, Portland, ME (United States); Temple, S.; Sengupta-Gopalan, C. [New Mexico State Univ., Las Curces, NM (United States)] [and others

    1996-05-15

    Oats (Avena sativa L. lodi) tolerant of rhizosphere infestation by Pseudomonas syringae pv. tabaci when challenged by the pathogen experience tissue-specific alterations of ammonia assimilatory capabilities. Altered ammonia assimilatory potentials between root and leaf tissue result from selective inactivation of glutamine synthetase (GS) by the toxin Tabtoxinine-B-lactam (TBL). Root GS is sensitive and leaf GSs are resistant to TBL inactivation. With prolonged challenge by the pathogen root GS activity decreases but leaf GS specific activity increase. Higher leaf GS activity is due to decreased rates of degradation rather than increased GS synthesis. Higher leaf GS activity and elevated levels of GS polypeptide appear to result from a limited interaction between GS and TBL leading to the accumulation of a less active but more stable GS holoenzyme. Tolerant challenged oats besides surviving rhizosphere infestation, experience enhanced growth. A strong correlation exists between leaf GS activity and whole plant fresh weight, suggesting that tissue-specific changes in ammonia assimilatory capability provides the plant a more efficient mechanism for uptake and utilization of nitrogen.

  4. Evaluating plant and plant oil repellency against the sweetpotato whitefly

    Science.gov (United States)

    The sweetpotato whitefly, Bemisia tabaci is a major insect pest of vegetables world-wide. We evaluated the effect of commercial plant oils – garlic oil, hot pepper wax, and mustard oil against B. tabaci. Cucumber plants served as the control. Additional treatments included no plants or oil (clear ai...

  5. Avaliação da preferência de Bemisia argentifolii por diferentes espécies de plantas Evaluation of Bemisia argentifolii preference for different plant species

    Directory of Open Access Journals (Sweden)

    Geni Litvin Villas Bôas

    2001-07-01

    Full Text Available Este trabalho teve como objetivo avaliar a preferência de Bemisia argentifolii em relação a algumas plantas hospedeiras potenciais como: abobrinha, feijão, repolho, tomate, mandioca, pepino, soja, pimentão, milho, poinsétia, brócolos e berinjela. Utilizou-se a metodologia de, em testes de livre escolha, expor uma população de mosca-branca previamente criada em plantas de poinsétia, às diversas espécies botânicas. Após 48h de exposição às diferentes espécies, insetos adultos e ovos presentes nas folhas foram contados e a área foliar medida, calculando-se o número de adultos e de ovos por cm² de área foliar. Em outro experimento, após três gerações de associação de uma população de mosca-branca com berinjela, repolho e mandioca, avaliou-se a utilização destas plantas como substrato para o desenvolvimento pré-imaginal de B. argentifolii. De maneira geral, as plantas abobrinha, tomate, feijão, pepino, berinjela, repolho e soja atraíram adultos de B. argentifolii, que efetuaram posturas nestas plantas. Mandioca, milho e pimentão foram as plantas menos preferidas. Uma relação positiva entre o número de adultos presentes, a área foliar e o número de posturas, sugere que o mecanismo de escolha do hospedeiro para alimentação e abrigo do adulto, envolve a conseqüente seleção do hospedeiro para oviposição. O número de adultos e ninfas foi maior em repolho e a porcentagem de ninfas vivas foi semelhante para repolho e berinjela. Em mandioca, uma elevada porcentagem de ninfas mortas demonstra não ser esta planta adequada para a sobrevivência do inseto.We evaluated the preference of Bemisia argentifolii for potential host plants such as zucchini, dry bean, cabbage, tomato, cassava, cucumber, soybean, sweet-pepper, corn, poinsettia, broccoli and eggplant. An insect population previously reared on poinsettia plants was placed in the presence of host plants during 48 hours in free-choice tests. The number of

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

    OpenAIRE

    Zhao, Haipeng; Zhang, Xiaoying; Xue, Ming; Zhang, Xiao

    2015-01-01

    Background The feeding of Bemisia tabaci nymphs trigger the SA pathway in some plant species. A previous study showed that B. tabaci nymphs induced defense against aphids (Myzus persicae) in tobacco. However, the mechanism underlying this defense response is not well understood. Methodology/Principal Findings Here, the effect of activating the SA signaling pathway in tobacco plants through B. tabaci nymph infestation on subsequent M. persicae colonization is investigated. Performance assays s...

  7. 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

  8. Light Suppresses Bacterial Population through the Accumulation of Hydrogen Peroxide in Tobacco Leaves Infected with Pseudomonas syringae pv. tabaci.

    Science.gov (United States)

    Cheng, Dan-Dan; Liu, Mei-Jun; Sun, Xing-Bin; Zhao, Min; Chow, Wah S; Sun, Guang-Yu; Zhang, Zi-Shan; Hu, Yan-Bo

    2016-01-01

    Pseudomonas syringae pv. tabaci (Pst) is a hemibiotrophic bacterial pathogen responsible for tobacco wildfire disease. Although considerable research has been conducted on the tobacco plant's tolerance to Pst, the role of light in the responses of the photosystems to Pst infection is poorly understood. This study aimed to elucidate the underlying mechanisms of the reduced photosystem damage in tobacco leaves due to Pst infection under light conditions. Compared to dark conditions, Pst infection under light conditions resulted in less chlorophyll degradation and a smaller decline in photosynthetic function. Although the maximal quantum yield of photosystem II (PSII) and the activity of the photosystem I (PSI) complex decreased as Pst infection progressed, damage to PSI and PSII after infection was reduced under light conditions compared to dark conditions. Pst was 17-fold more abundant in tobacco leaves under dark compared to light conditions at 3 days post inoculation (dpi). Additionally, H2O2 accumulated to a high level in tobacco leaves after Pst infection under light conditions; although to a lesser extent, H2O2 accumulation was also significant under dark conditions. Pretreatment with H2O2 alleviated chlorotic lesions and decreased Pst abundance in tobacco leaves at 3 dpi under dark conditions. MV pretreatment had the same effects under light conditions, whereas 3-(3,4-dichlorophenyl)-1,1-dimethylurea pretreatment aggravated chlorotic lesions and increased the Pst population. These results indicate that chlorotic symptoms and the size of the bacterial population are each negatively correlated with H2O2 accumulation. In other words, light appears to suppress the Pst population in tobacco leaves through the accumulation of H2O2 during infection. PMID:27148334

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

    Directory of Open Access Journals (Sweden)

    Germano Leão Demolin Leite

    2005-01-01

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

  10. Host plant pubescence: Effect on silverleaf whitefly, Bemisia argentifolii, fourth instar and pharate adult dimensions and ecdysteroid titer fluctuations

    Directory of Open Access Journals (Sweden)

    Dale B. Gelman

    2003-08-01

    Full Text Available The ability to generate physiologically synchronous groups of insects is vital to the performance of investigations designed to test insect responses to intrinsic and extrinsic stimuli. During a given instar, the silverleaf whitefly, Bemisia argentifolii, increase in depth but not in length or width. A staging system to identify physiologically synchronous 4th instar and pharate adult silverleaf whiteflies based on increasing body depth and the development of the adult eye has been described previously. This study determined the effect of host plant identity on ecdysteroid fluctuations during the 4th instar and pharate adult stages, and on the depth, length and width dimensions of 4th instar/pharate adult whiteflies. When grown on the pubescent-leafed green bean, tomato and poinsettia plants, these stages were significantly shorter and narrower, but attained greater depth than when grown on the glabrous-leafed cotton, collard and sweet potato plants. Thus, leaf pubescence is associated with reduced length and width dimensions, but increased depth dimensions in 4th instars and pharate adults. For all host plants, nymphal ecdysteroid titers peaked just prior to the initiation of adult development. However, when reared on pubescent-leafed plants, the initiation of adult development typically occurred in nymphs that had attained a depth of 0.2 to 0.25 mm (Stage 3 - 4. When reared on glabrous-leafed plants, the initiation of adult development typically occurred earlier, in nymphs that had attained a depth of only 0.15-0.18 mm (Stage 2 Old - early 3. Therefore, based on ecdysteroid concentration, it appears that Stage-2, -3 and -4/5 nymphs reared on pubescent-leafed plants are physiologically equivalent to Stage-1, -2 Young and -2 Old/3, respectively, nymphs reared on glabrous-leafed plants. The host plant affected the width but not the height of the nymphal-adult premolt ecdysteroid peak. However, leaf pubescence was not the determining factor. Thus

  11. Biological control strategies for the South American tomato moth (Lepidoptera: Gelechiidae) in greenhouse tomatoes.

    Science.gov (United States)

    Cabello, Tomas; Gallego, Juan R; Fernandez, Francisco J; Gamez, Manuel; Vila, Enric; Del Pino, Modesto; Hernandez-Suarez, Estrella

    2012-12-01

    The South American tomato pinworm, Tuta absoluta (Meyrick) has been introduced into new geographic areas, including the Mediterranean region, where it has become a serious threat to tomato production. Three greenhouse trials conducted in tomato crops during 2009 and 2010 explored control strategies using the egg-parasitoid Trichogramma achaeae Nagaraja and Nagarkatti compared with chemical control. The effectiveness of the predator Nesidiocoris tenuis (Reuter) was also tested. In greenhouses with early pest infestations (discrete generations), periodic inundative releases (eight releases at a rate of 50 adults/m2, twice a week) were necessary to achieve an adequate parasitism level (85.63 +/- 5.70%) early in the growing season. However, only one inoculative release (100 adults/m2) was sufficient to achieve a comparatively high parasitism level (91.03 +/- 12.58%) under conditions of high pest incidence and overlapping generations. Some intraguild competition was observed between T. achaeae and the predator, N. tenuis. This mirid species is commonly used in Mediterranean greenhouse tomato crops for the control of the sweetpotato whitefly, Bemisia tabaci (Gennadius). Tomato cultivars were also observed to influence the activity of natural enemies, mainly N. tenuis (whose average numbers ranged between 0.17 +/- 0.03 and 0.41 +/- 0.05 nymphs per leaf depending on the cultivar). This may be because of differences in plant nutrients in different cultivars, which may affect the feeding of omnivorous insects. In contrast, cultivar effects on T. achaeae were less apparent or possibly nonexistent. Nevertheless, there was an indirect effect in as much as T. achaeae was favored in cultivars not liked by N. tenuis. PMID:23356074

  12. Generating Within-Plant Spatial Distributions of an Insect Herbivore Based on Aggregation Patterns and Per-Node Infestation Probabilities.

    Science.gov (United States)

    Rincon, Diego F; Hoy, Casey W; Cañas, Luis A

    2015-04-01

    Most predator-prey models extrapolate functional responses from small-scale experiments assuming spatially uniform within-plant predator-prey interactions. However, some predators focus their search in certain plant regions, and herbivores tend to select leaves to balance their nutrient uptake and exposure to plant defenses. Individual-based models that account for heterogeneous within-plant predator-prey interactions can be used to scale-up functional responses, but they would require the generation of explicit prey spatial distributions within-plant architecture models. The silverleaf whitefly, Bemisia tabaci biotype B (Gennadius) (Hemiptera: Aleyrodidae), is a significant pest of tomato crops worldwide that exhibits highly aggregated populations at several spatial scales, including within the plant. As part of an analytical framework to understand predator-silverleaf whitefly interactions, the objective of this research was to develop an algorithm to generate explicit spatial counts of silverleaf whitefly nymphs within tomato plants. The algorithm requires the plant size and the number of silverleaf whitefly individuals to distribute as inputs, and includes models that describe infestation probabilities per leaf nodal position and the aggregation pattern of the silverleaf whitefly within tomato plants and leaves. The output is a simulated number of silverleaf whitefly individuals for each leaf and leaflet on one or more plants. Parameter estimation was performed using nymph counts per leaflet censused from 30 artificially infested tomato plants. Validation revealed a substantial agreement between algorithm outputs and independent data that included the distribution of counts of both eggs and nymphs. This algorithm can be used in simulation models that explore the effect of local heterogeneity on whitefly-predator dynamics. PMID:26313173

  13. Farmers’ knowledge and perceptions of potato pests and their management in Uganda

    Directory of Open Access Journals (Sweden)

    Joshua Sikhu Okonya

    2016-03-01

    Full Text Available As we initiate entomological research on potato (Solanum tuberosum L. in Uganda, there is need to understand farmers’ knowledge of existing insect pest problems and their management practices. Such information is important for designing a suitable intervention and successful integrated pest management (IPM strategy. A farm household survey using a structured questionnaire was conducted among 204 potato farmers in six districts of Uganda (i.e., Kabale, Kisoro, Mbale, Kapchorwa, Mubende, and Kyegegwa during August and September 2013. Diseases, insect pests, price fluctuations, and low market prices were the four highest ranked constraints in potato production, in order of decreasing importance. Cutworms (Agrotis spp., aphids (Myzus persicae (Sulzer, and potato tuber moth (Phthorimaea operculella (Zeller were the three most severe insect pests. Ants (Dorylis orantalis Westwood, whiteflies (Bemisia tabaci (Gennadius, and leafminer flies (Liriomyza huidobrensis (Blanchard were pests of moderate importance. Major yield losses are predominantly due to late blight (Phytophthora infestans (Mont. de Bary and reached 100% without chemical control in the districts of Kabale, Kisoro, Mbale, and Kapchorwa. On average, farmers had little to moderate knowledge about pest characteristics. The predominant control methods were use of fungicides (72% of respondents and insecticides (62% of respondents. On average, only 5% of the 204 farmers knew about insect pests and their natural enemies. This lack of knowledge calls for training of both farmers and extension workers in insect pest identification, their biology, and control. Empowering farmers with knowledge about insect pests is essential for the reduction of pesticide misuse and uptake of more environmentally friendly approaches like IPM. Field surveys would need follow-up in order to assess the actual field infestation rates and intensities of each insect pest and compare the results with the responses

  14. 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 (< 1.0) at week 4 compared with imidacloprid-treated plants (23.7-25.3). The uptake of dinotefuran into poinsettia plants was also more rapid and resulted in quicker and higher percent mortality of 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. PMID:22606821

  15. 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

    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...

  16. Determining the role of ethylene biosynthesis in the development of tomato irregular ripening disorder using microarray technology and rt-real time PCR.

    Science.gov (United States)

    Whiteflies, Bemisia tabaci biotype B, are associated with a plant physiological disorder termed tomato irregular ripening. Symptoms of tomato irregular ripening disorder do not appear on tomato foliage where whitefly feed, but appear as an uneven fruit color development during ripening in tomato. Th...

  17. Metablic Coevolution in the bacterial symbiosis of whiteflies and related plant sap-feeding insects

    Science.gov (United States)

    In animals dependent on intracellular bacteria with very small genomes, the host cell is adapted to support the function of its bacterial symbionts, but the molecular basis of these adaptations is poorly understood. We investigated the metabolic coevolution between the whitefly Bemisia tabaci and th...

  18. The effect of time of whitefly infestation and plant nutrition on the development of tomato irregular ripening disorder

    Science.gov (United States)

    Tomato irregular ripening (TIR) is a physiological plant disorder caused by Bemisia tabaci biotype B feeding on foliage and resulting in incomplete ripening of longitudinal sections of fruit.Our objective was to determine the effect of time of whitefly infestation and plant nutrition on the developm...

  19. Companion and refuge plants to control insect pests

    Science.gov (United States)

    Introduction: The sweetpotato whitefly, Bemisia tabaci and aphids are major pests of crops in the southeast USA. An environmentally-friendly management strategy is “push-pull” technology which combines the use of repellent (“push”) and trap crops (“pull”) for insect pest control. The repellent crop,...

  20. Establishment and impact of exotic aphelinid parasitoids in Arizona: A life table approach

    Science.gov (United States)

    A large multi-institutional, interagency classical biological control program was initiated in the early 1990s to combat the invasion of the B biotype of Bemisia tabaci into the USA. This large program was successful in the discovery, importation, rearing and release of more than 30 species/strains...

  1. THE Q-BIOTYPE WHITEFLY

    Science.gov (United States)

    In 2004, the Q-biotype of the sweetpotato whitefly, Bemisia tabaci, was identified in the U.S. for the first time. The level of insecticide resistance to pyriproxyfen (Distance) and imidacloprid (Marathon) of the Q-biotype was higher than any U.S. population of B-biotype whiteflies (silverleaf white...

  2. Management of watermelon vine decline in Florida

    Science.gov (United States)

    Squash vein yellowing virus (SqVYV), the causal agent of watermelon vine decline (WVD) in Florida, is vectored by the silverleaf whitefly Bemisia tabaci (Biotype “B”). Watermelon plants mechanically inoculated at different growth stages from transplant to fruit formation with SqVYV developed WVD sy...

  3. Biotype investigation

    Science.gov (United States)

    This article gives the background to the recent invasion of the USA by the Q biotype Bemisia tabaci. It also describes recent results comparing the efficacy of insecticides against the B and Q biotypes of this important pest whitefly. Both biotypes are controllable with pesticides, although there ar...

  4. Whiteflies

    Science.gov (United States)

    Whiteflies have long been considered a major pest of ornamentals. Before 1986, the primary pest species was the greenhouse whitefly until Bemisia tabaci was found attacking an array of ornamental plants in Florida greenhouses. The Q biotype was detected in Arizona in 2004 and is problematic because ...

  5. Tracking disease and insect pests using Smartphone technology: a new approach for regional (and local) pest management

    Science.gov (United States)

    Tomato yellow leaf curl virus (TYLCV) is vectored by the silverleaf whitefly (Bemisia tabaci biotype B) and was first detected in south Florida in 1997. The virus has spread widely in Florida and is responsible for millions of dollars of lost production. Anlaysis of data from a comprehensive, multi-...

  6. Função bioquímica da via daslipoxigenases em plantas de soja submetidas ao ataque de mosca-branca (Bemisia argentifolii Biochemical function of lipoxygenases pathway of soybean plants submitted to the attack of whitefly (Bemisia argentifolii

    Directory of Open Access Journals (Sweden)

    Francine Barbosa Silva

    2004-04-01

    Full Text Available Neste trabalho, avaliou-se a capacidade da planta de soja de uma cultivar comercial, IAC-100, e de um genótipo IAC-100 TN que apresenta ausência de lipoxigenases nas sementes de responderem ao ataque de mosca-branca (Bemisia argentifolii pela via das Lipoxigenases. Foi realizada a caracterização cinética do pool de lipoxigenases. Os valores de KMapp decresceram nas plantas atacadas, sugerindo uma alteração no pool de lipoxigenases foliares. Valores similares de KMapp, entre os genótipos, indicam que a remoção de lipoxigenases de sementes não interferiram na expressão de lipoxigenases em folhas. Ocorreu aumento significativo na produção de inibidores de proteases. Com esses resultados, infere-se que a produção de inibidores de proteases está envolvida no mecanismo de defesa de soja ao ataque da mosca-branca.This work evaluated the capacity of the soybean plant, from a commercial cultivar IAC-100 and from a genotype IAC-100 TN, with absence of lipoxygenases in their seeds, to respond to the attack by whitefly (sucking insect by lipoxygenases pathway. The kinetic characterization of the “pool” of lipoxygenases was determined. The KMapp values decreased, suggesting a change in the “pool” of lipoxygenases in response to the attack by whitefly. The similar KMapp values suggest that the removal of the lipoxygenases from the seeds does not change the expression of LOX in the leaves. There was a noticeable increase in protease inhibitors. These results suggest that the production of protease inhibitors are involved in the defense mechanism of soybean plant against whitefly injury.

  7. A Survey of the Insect Pests and Farmers' Practices in the Cropping of Tomato in Nigeria

    OpenAIRE

    Umeh, VC.; Kuku, FO.; Nwanguma, EI.; Adebayo, OS.; Manga, AA.

    2002-01-01

    A survey of some tomato producing areas of Nigeria indicated that the major insects attacking tomato included the fruit borer Helicoverpa armigera Hübner, the grasshopper Zonocerus variegatus L., the whitefly Bemisia tabacci Gennadius, and various species of aphids, mostly Aphis gossypii Glover. Interviews conducted to assess farmers' practices which contribute to insect damage showed that inappropriate application of insecticides and the use of wrong dosages may have contributed to insect co...

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

    Directory of Open Access Journals (Sweden)

    Germano Leão Demolin Leite

    2002-07-01

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

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

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  10. Differential and Synergistic Functionality of Acylsugars in Suppressing Oviposition by Insect Herbivores.

    Directory of Open Access Journals (Sweden)

    Brian M Leckie

    Full Text Available Acylsugars are secondary metabolites exuded from type IV glandular trichomes that provide broad-spectrum insect suppression for Solanum pennellii Correll, a wild relative of cultivated tomato. Acylsugars produced by different S. pennellii accessions vary by sugar moieties (glucose or sucrose and fatty acid side chains (lengths and branching patterns. Our objective was to determine which acylsugar compositions more effectively suppressed oviposition of the whitefly Bemisia tabaci (Gennadius (Middle East--Asia Minor 1 Group, tobacco thrips, Frankliniella fusca (Hinds, and western flower thrips, Frankliniella occidentalis (Pergande. We extracted and characterized acylsugars from four S. pennellii accessions with different compositions, as well as from an acylsugar-producing tomato breeding line. We also fractionated the acylsugars of one S. pennellii accession to examine the effects of its components. Effects of acylsugars on oviposition were evaluated by administering a range of doses to oviposition sites of adult whiteflies and thrips in non-choice and choice bioassays, respectively. The acylsugars from S. pennellii accessions and the tomato breeding line demonstrated differential functionality in their ability to alter the distribution of whitefly oviposition and suppress oviposition on acylsugar treated substrates. Tobacco thrips were sensitive to all compositions while western flower thrips and whiteflies were more sensitive to acylsugars from a subset of S. pennellii accessions. It follows that acylsugars could thus mediate plant-enemy interactions in such a way as to affect evolution of host specialization, resistance specificity, and potentially host differentiation or local adaptation. The acylsugars from S. pennellii LA1376 were separated by polarity into two fractions that differed sharply for their sugar moieties and fatty acid side chains. These fractions had different efficacies, with neither having activity approaching that of the

  11. Repellent and Attractive Effects of α-, β-, and Dihydro-β- Ionone to Generalist and Specialist Herbivores.

    Science.gov (United States)

    Cáceres, L A; Lakshminarayan, S; Yeung, K K-C; McGarvey, B D; Hannoufa, A; Sumarah, M W; Benitez, X; Scott, I M

    2016-02-01

    In plants, the oxidative cleavage of carotenoid substrates produces volatile apocarotenoids, including α-ionone, β-ionone, and dihydro-β-ionone, compounds that are important in herbivore-plant communication. For example, β-ionone is part of an induced defense in canola, Brassica napus, and is released following wounding by herbivores. The objectives of the research were to evaluate whether these volatile compounds would: 1) be released in higher quantities from plants through the over-expression of the carotenoid cleavage dioxygenase1 (CCD1) gene and 2) cause herbivores to be repelled or attracted to over-expressing plants relative to the wild-type. In vivo dynamic headspace collection of volatiles coupled with gas chromatography-mass spectrometry was used to determine volatile organic compounds (VOC) in the headspace of the Arabidopsis thaliana ecotype Columbia-0 (L.) over-expressing the AtCCD1 gene. The analytical method allowed the detection of β-ionone in the Arabidopsis headspace where emission rates ranged between 2 and 5-fold higher compared to the wild type, thus corroborating the in vivo enhancement of gene expression. A two chamber choice test between wild type and AtCCD1 plants revealed that crucifer flea beetle Phyllotreta cruciferae (Goeze) adults were repelled by the AtCCD1 plants with the highest transcription and β-ionone levels. α-Ionone and dihydro-β-ionone were not found in the headspace analysis, but solutions of the three compounds were tested in the concentration range of β-ionone found in the Arabidopsis headspace (0.05 to 0.5 ng/μl) in order to assess their biological activity with crucifer flea beetle, two spotted spider mite Tetranychus urticae (Koch), and silverleaf whiteflies Bemisia tabaci (Gennadius). Choice bioassays demonstrated that β-ionone has a strong repellent effect toward both the flea beetle and the spider mite, and significant oviposition deterrence to whiteflies. In contrast, dihydro-β-ionone had attractant

  12. Differential and Synergistic Functionality of Acylsugars in Suppressing Oviposition by Insect Herbivores.

    Science.gov (United States)

    Leckie, Brian M; D'Ambrosio, Damon A; Chappell, Thomas M; Halitschke, Rayko; De Jong, Darlene M; Kessler, André; Kennedy, George G; Mutschler, Martha A

    2016-01-01

    Acylsugars are secondary metabolites exuded from type IV glandular trichomes that provide broad-spectrum insect suppression for Solanum pennellii Correll, a wild relative of cultivated tomato. Acylsugars produced by different S. pennellii accessions vary by sugar moieties (glucose or sucrose) and fatty acid side chains (lengths and branching patterns). Our objective was to determine which acylsugar compositions more effectively suppressed oviposition of the whitefly Bemisia tabaci (Gennadius) (Middle East-Asia Minor 1 Group), tobacco thrips, Frankliniella fusca (Hinds), and western flower thrips, Frankliniella occidentalis (Pergande). We extracted and characterized acylsugars from four S. pennellii accessions with different compositions, as well as from an acylsugar-producing tomato breeding line. We also fractionated the acylsugars of one S. pennellii accession to examine the effects of its components. Effects of acylsugars on oviposition were evaluated by administering a range of doses to oviposition sites of adult whiteflies and thrips in non-choice and choice bioassays, respectively. The acylsugars from S. pennellii accessions and the tomato breeding line demonstrated differential functionality in their ability to alter the distribution of whitefly oviposition and suppress oviposition on acylsugar treated substrates. Tobacco thrips were sensitive to all compositions while western flower thrips and whiteflies were more sensitive to acylsugars from a subset of S. pennellii accessions. It follows that acylsugars could thus mediate plant-enemy interactions in such a way as to affect evolution of host specialization, resistance specificity, and potentially host differentiation or local adaptation. The acylsugars from S. pennellii LA1376 were separated by polarity into two fractions that differed sharply for their sugar moieties and fatty acid side chains. These fractions had different efficacies, with neither having activity approaching that of the original exudate

  13. Effect of commercially available plant-derived essential oil products on arthropod pests.

    Science.gov (United States)

    Cloyd, Raymond A; Galle, Cindy L; Keith, Stephen R; Kalscheur, Nanette A; Kemp, Kenneth E

    2009-08-01

    Plant-derived essential oil products, in general, are considered minimum-risk pesticides and are exempt from Environmental Protection Agency registration under section 25(b) of the Federal Insecticide Fungicide and Rodenticide Act. However, many of the plant-derived essential products available to consumers (homeowners) have not been judiciously evaluated for both efficacy and plant safety. In fact, numerous plant-derived essential oil products labeled for control of arthropod pests have not been subject to rigorous evaluation, and there is minimal scientific information or supporting data associated with efficacy against arthropod pests. We conducted a series of greenhouse experiments to determine the efficacy and phytotoxicity of an array of plant-derived essential oil products available to consumers on arthropod pests including the citrus mealybug, Planococcus citri (Risso); western flower thrips, Frankliniella occidentalis (Pergande); twospotted spider mite, Tetranychus urticae Koch; sweetpotato whitefly B-biotype, Bemisia tabaci (Gennadius); and green peach aphid, Myzus persicae (Sulzer). Although the products Flower Pharm (cottonseed, cinnamon, and rosemary oil) and Indoor Pharm (soybean, rosemary, and lavender oil) provided > 90% mortality of citrus mealybug, they were also the most phytotoxic to the coleus, Solenostemon scutellarioides (L.) Codd, plants. Both GC-Mite (cottonseed, clove, and garlic oil) and Bugzyme (citric acid) were most effective against the twospotted spider mite (> or = 90% mortality). However, SMC (canola, coriander oil, and triethanolamine), neem (clarified hydrophobic extract of neem oil), and Bug Assassin (eugenol, sodium lauryl sulfate, peppermint, and citronella oil) provided > 80% mortality. Monterey Garden Insect Spray, which contained 0.5% spinosad, was most effective against western flower thrips with 100% mortality. All the other products evaluated failed to provide sufficient control of western flower thrips with or = 4.5 of

  14. Comparative efficacy of different insecticides against sucking pests of cotton

    International Nuclear Information System (INIS)

    Seven insecticides, viz. Mospilan 20SP, Confider 200SL, Talstar 10EC, Advantage 20EC, Actara 25WG, Polo 500EC and Tamaron 60SL were evaluated for their efficacy against jassid (Amarasca devastans Dist., (Whitefly (Bemisia tabaci (Genn.)) and thrips (Thrips tabaci Lind.) on cotton, at the University College of Agriculture, Bahauddin Zakariya University, Multan. The most effective insecticides for jassid, up to seven days were Confider and Mospilan, while Advantage was ineffective to control jassid population. Against whitefly the most effective insecticides were Mospilan and Actara, while Mospilan, Confidor and Tamaron were highly effective against thrips. (author)

  15. Evidence For Rapid Spatiotemporal Changes in Genetic Structure of an Alien Whitefly During Initial Invasion

    OpenAIRE

    Chu, Dong; Guo, Dong; Tao, Yunli; Jiang, Defeng; Jie LI; Zhang, Youjun

    2014-01-01

    The sweetpotato whitefly Bemisia tabaci Q species is a recent invader and important pest of agricultural crops in China. This research tested the hypothesis that the Q populations that establish in agricultural fields in northern China each year are derived from multiple secondary introductions and/or local populations that overwinter in greenhouses (the pest cannot survive winters in the field in northern China). Here, we report the evidence that the Q populations in agricultural fields main...

  16. Introduced sap-feeding insect pests of crop plants in the Maltese Islands

    OpenAIRE

    Mifsud, David; Watson, Gillian W.

    1999-01-01

    Sap-feeding insects within Hemiptera and Thysanoptera are some of the most important crop pests world-wide. Apart from the loss of yield they cause by sap depletion, saliva toxicity and soiling of the leaves, some species transmit serious plant virus diseases. Important sap-feeding species that have been introduced to the Maltese Islands include the whitefly Bemisia tabaci; the scale insects Pseudococcus longispinus, Planococcus citri and Icerya purchasi; the aphids Aphis gossypii...

  17. Systemic Nicotinoid Toxicity against the Predatory Mirid Pilophorus typicus : Residual Side Effect and Evidence for Plant Sucking

    OpenAIRE

    Nakahira, Kengo; Kashitani, Ryoya; Tomoda, Masafumi; Kodama, Rika; Ito, Katsura; Yamanaka, Satoshi; Momoshita, Mitsutoshi; Arakawa, Ryo; Takagi, Masami

    2011-01-01

    The predatory mirid Pilophorus typicus (Heteroptera: Miridae) is a potential biological control agent against Bemisia tabaci (Hemiptera: Aleyrodidae), but the sucking for host plant is unknown. To investigate collaboration use of P. typicus and nicotinoid granules and to confirm the sucking for pepper plant, residual harmful toxicity of 4 nicotinoids: acetamiprid; imidacloprid; nitempyram; and thiamethoxam on P. typicus adult were investigated at 7, 14 21, 28 and 35 d after treatment of the n...

  18. Cotton transgenics with Antisense AC1 gene for resistance against cotton leaf curl virus

    OpenAIRE

    J.Amudha, G.Balasubramani, V.G.Malathi, D.Monga, K.C.Bansal and K.R.Kranthi

    2010-01-01

    Cotton leaf curl virus is a devastating pest in the North India and in small pockets of Southern states. Cotton leaf curldisease (CLCuD) is caused by a Geminivirus, transmitted by whitefly Bemisia tabaci vector. This is a serious problem inthe northern region and leads to yield losses up to 58% and 69% (ICAC recorder, 1999). Genetic engineering for cottontransgenics resistant to leaf curl disease (CLCuD) through antisense RNA approach is potential to tackle the disease incotton. Cotton transg...

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

    OpenAIRE

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

    2015-01-01

    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...

  20. Competitive Interactions between Parasitoids Provide New Insight into Host Suppression

    OpenAIRE

    Xu, Hai-Yun; Yang, Nian-Wan; Wan, Fang-Hao

    2013-01-01

    Understanding the dynamics of potential inter- and intraspecific competition in parasitoid communities is crucial in the screening of efficient parasitoid species and for utilization of the best parasitoid species combinations. In this respect, the host-parasitoid systems, Bemisia tabaci and two parasitoids, Eretmocerus hayati (exotic) and Encarsia sophia (existing) were studied under laboratory conditions to investigate whether interference competition between the exotic and existing species...

  1. Identification of whitefly resistance in tomato and hot pepper

    OpenAIRE

    Firdaus, S.

    2012-01-01

    Key words: Capsicum, Bemisia tabaci, trichome density, cuticle thickness Whitefly is economically one of the most threatening pests of pepper worldwide, which is mainly caused by its ability to transmit many different viruses. In this research, we characterized pepper germplasm to identify whitefly-resistant accessions that will form the basis for future resistance breeding. Forty-four pepper accessions representing four species (Capsicum annuum, C. frutescens, C. chinense, C. baccatum) were ...

  2. Influence of Additives on the Yield and Pathogenicity of Conidia Produced by Solid State Cultivation of an Isaria javanica Isolate

    OpenAIRE

    Kim, Jeong Jun; Xie, Ling; Han, Ji Hee; Lee, Sang Yeob

    2014-01-01

    Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of Bemisia tabaci worldwide, because of its increased resistance to some insecticide groups. As an alternative control agent, we selected an Isaria javanica isolate as a candidate for the development of a mycopesticide against the Q biotype of sweet potato whitefly. To select optimal mass production media for solid-state fermentation, we compared the production yield and virulence of conidia between 2...

  3. Comparative Efficacy of Insecticides, Insect Growth Regulator and M.Y. Strategy Against Insect Pets of Okra (Abelmoschus esculentus

    Directory of Open Access Journals (Sweden)

    Muhammad Tariq

    2000-01-01

    Full Text Available The efficacy of Azodrin and Pirate (insecticides, Cascade (insect growth regulator and Pressurized water spray (M. Y. strategy was evaluated against insect pests of okra. Cascade was found to be the best efficient against Helicoverpa armigera and Earias spp. Pirate showed maximum efficacy against Amrasca biguttula biguttula, whereas, against Bemisia tabaci, the most effective treatment was Azodrin followed by M.Y. strategy.

  4. Differential profiles of direct and indirect modification of vector feeding behaviour by a plant virus

    OpenAIRE

    Wen-Bo He; Jie Li; Shu-Sheng Liu

    2015-01-01

    Plant viruses interact with their insect vectors directly and indirectly via host plants, and this tripartite interaction may produce fitness benefits to both the vectors and the viruses. Our previous studies show that the Middle East-Asia Minor 1 (MEAM1) species of the whitefly Bemisia tabaci complex improved its performance on tobacco plants infected by the Tomato yellow leaf curl China virus (TYLCCNV), which it transmits, although virus infection of the whitefly per se reduced its performa...

  5. New experimental tools for bioassays with whitefly in laboratory

    Directory of Open Access Journals (Sweden)

    Thiago Luis Martins Fanela

    2012-12-01

    Full Text Available The objective of this work was to develop an experimental kit for assessments of repellency, deterrence for oviposition, and insecticidal activity on adults of the whitefly Bemisia tabaci biotype B. The kit, which consisted of arenas and nebulizer, was effective for conducting bioassays, and the application of aqueous extracts by inhaler was adequate. The techniques are simple, cheap, and may contribute to research on this insect.

  6. Tomato yellow leaf curl virus differentially influences plant defence responses to a vector and a non-vector herbivore.

    Science.gov (United States)

    Su, Qi; Mescher, Mark C; Wang, Shaoli; Chen, Gong; Xie, Wen; Wu, Qingjun; Wang, Wenkai; Zhang, Youjun

    2016-03-01

    Plants frequently engage in simultaneous interactions with diverse classes of biotic antagonists. Differential induction of plant defence pathways by these antagonists, and interactions between pathways, can have important ecological implications; however, these effects are currently not well understood. We explored how Tomato yellow leaf curl virus (TYLCV) influenced the performance of its vector (Bemisia tabaci) and a non-vector herbivore (Tetranychus urticae) occurring separately or together on tomato plants (Solanum lycopersicum). TYLCV enhanced the performance of B. tabaci, although this effect was statistically significant only in the absence of T. urticae, which adversely affected B. tabaci performance regardless of infection status. In contrast, the performance of T. urticae was enhanced (only) by the combined presence of TYLCV and B. tabaci. Analyses of phytohormone levels and defence gene expression in wild-type tomatoes and various plant-defence mutants indicate that the enhancement of herbivore performance (for each species) entails the disruption of downstream defences in the jasmonic acid (JA) pathway. For T. urticae, this disruption appears to involve antagonistic effects of salicylic acid (SA), which is cumulatively induced to high levels by B. tabaci and TYLCV. In contrast, TYLCV was found to suppress JA-mediated responses to B. tabaci via mechanisms independent of SA. PMID:26436779

  7. 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.

  8. Effects of plant virus and its insect vector on Encarsia formosa, a biocontrol agent of whiteflies.

    Science.gov (United States)

    Liu, Xiaoyuan; Xiang, Wensheng; Jiao, Xiaoguo; Zhang, Youjun; Xie, Wen; Wu, Qingjun; Zhou, Xuguo; Wang, Shaoli

    2014-01-01

    In this study, we investigated the tritrophic interactions among a persistently transmitted plant virus, Tomato yellow leaf curl virus (TYLCV), its insect vector, the sweetpotato whitefly Bemisia tabaci, and a parasitoid, Encarsia formosa Gahan, one of the most extensively used biological control agents. As an emerging invasive pest worldwide, the two most damaging whiteflies are B. tabaci B and Q cryptic species. On healthy tomato plants, parasitoid-induced mortality was significantly higher in B. tabaci B than in Q. In contrast, similar mortality levels of B and Q were observed on TYLCV-infected plants. A higher rate of parasitism was consistently observed in B, independent of the TYLCV infection. Similarly, the life history traits of E. formosa were influenced by both TYLCV and the two cryptic species of B. tabaci. Specifically, E. formosa parasitizing B had a greater adult longevity and shorter developmental time on healthy plants, whereas the parasitoids developing from Q has a greater adult longevity on TYLCV-infected plants. The emergence rate of E. formosa was unaffected by either B. tabaci cryptic species or the virus. These results suggest that the vector-borne pathogen can manipulate the host suitability of a parasitoid and hence the parasitoid-host interactions. PMID:25096549

  9. Compatibilidad in vitro de un bioplaguicida a base de Lecanicillium lecanii (Hypocreales: Clavicipitaceae con agroquímicos empleados en los cultivos de algodón y berenjena

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    Adriana Marcela Santos Díaz

    2013-12-01

    Full Text Available In vitro compatibility of the biopesticide based on Lecanicillium lecanii (Hypocreales: Clavicipitaceae with agrochemicals used in cotton and eggplant cropsResumen: El aislamiento colombiano de Lecanicillium lecanii Vl026 formulado como un granulado dispersable WG, ha demostrado una alta eficiencia para el control de Bemisia tabaci en los cultivos de algodón y berenjena. Teniendo en cuenta el potencial de este bioinsumo, el objetivo del siguiente fue determinar la compatibilidad in vitro del bioplaguicida a base de L. lecanii con agroquímicos (insecticidas y fungicidas que se utilizan con mayor frecuencia en dichos cultivos. La compatibilidad in vitro se estableció determinando el porcentaje de germinación (% y las Unidades Formadoras de Colonia (UFC en presencia de los plaguicidas y estimando la concentración inhibitoria 10 (CI10. Cada plaguicida se evaluó a la dosis recomendada, a la mitad y a un cuarto de ésta. Los fungicidas químicos  (Benomil®, Vitavax®, Ridomil® y Manzate® no fueron compatibles con L. lecanii, ya que inhibieron la germinación y las Unidades Formadoras de Colonia del hongo en las tres dosis evaluadas. En cuanto a los insecticidas químicos, el producto Confidor® no inhibió la viabilidad en comparación con el tratamiento control, considerándose compatible con el bioplaguicida. Cuando se evaluó la dosis completa de los demás insecticidas (Oportune®, Actara®, Match® y Malathion® se obtuvieron germinaciones inferiores al 80%, por lo que dichos productos se clasificaron como no compatibles con el bioplaguicida a base de L. lecanii. El único agroquímico que fue compatible en condiciones in vitro con L. lecanii fue el producto Confidor®. Sin embargo, se recomienda evaluar el efecto in vivo de los productos químicos habitualmente utilizados por los agricultores sobre L. lecanii, con el propósito de desarrollar y establecer estrategias de manejo integrado de la mosca blanca Bemisia tabaci

  10. 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

    OpenAIRE

    Kátia Maria de Medeiros Siqueira; Angela Maria Isidro Farias

    2003-01-01

    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 c...

  11. Persistent, circulative transmission of begomoviruses by whitefly vectors.

    Science.gov (United States)

    Rosen, Ran; Kanakala, Surapathrudu; Kliot, Adi; Cathrin Pakkianathan, Britto; Farich, Basheer Abu; Santana-Magal, Nadine; Elimelech, Meytar; Kontsedalov, Svetlana; Lebedev, Galina; Cilia, Michelle; Ghanim, Murad

    2015-12-01

    Begomoviruses comprise an emerging and economically important group of plant viruses exclusively transmitted by the sweetpotato whitefly Bemisia tabaci in many regions of the world. The past twenty years have witnessed significant progress in studying the molecular interactions between members of this virus group and B. tabaci. Mechanisms and proteins encoded by the insect vector and its bacterial symbionts, which have been shown to be important for virus transmission, have been identified and thoroughly studied. Despite the economic importance of this group of viruses and their impact on the global agriculture, progress in investigating the virus-vector interactions is moving slowly when compared with similar virus-vector systems in plants and animals. Major advances in this field and future perspectives will be discussed in this review. PMID:26196230

  12. Factors affecting attack rate of whitefly on the eggplant

    Directory of Open Access Journals (Sweden)

    Leite Germano Leão Demolin

    2003-01-01

    Full Text Available The objective of this study was to determine the effects of weather, predators and parasitoids, canopy height and plant age, leaf chemical composition, levels of leaf N and K and leaf trichomes on the intensity of Bemisia tabaci attack on Solanum melongena. A higher density of nymph and whitefly adults was recorded at the base and medium of the plant compared to the apex. A higher number of eggs was observed on the medium part than on the apical and base part of the plants dossel. An increase in the density of whitefly is associated with an increase in temperature.

  13. Enhanced Whitefly Resistance in Transgenic Tobacco Plants Expressing Double Stranded RNA of v-ATPase A Gene

    OpenAIRE

    Thakur, Nidhi; Upadhyay, Santosh Kumar; Verma, Praveen C.; Chandrashekar, Krishnappa; Tuli, Rakesh; Singh, Pradhyumna K.

    2014-01-01

    Background Expression of double strand RNA (dsRNA) designed against important insect genes in transgenic plants have been shown to give protection against pests through RNA interference (RNAi), thus opening the way for a new generation of insect-resistant crops. We have earlier compared the efficacy of dsRNAs/siRNAs, against a number of target genes, for interference in growth of whitefly (Bemisia tabaci) upon oral feeding. The v-ATPase subunit A (v-ATPaseA) coding gene was identified as a cr...

  14. Lethal and sublethal effects of thiamethoxam on the whitefly predator Serangium japonicum (Coleoptera: Coccinellidae) through different exposure routes.

    Science.gov (United States)

    Yao, Feng-Luan; Zheng, Yu; Zhao, Jian-Wei; Desneux, Nicolas; He, Yu-Xian; Weng, Qi-Yong

    2015-06-01

    Given expectations for a booming usage of thiamethoxam and increasing availability of the promising biological agent Serangium japonicum for the control of Bemisia tabaci in China, an evaluation of their compatibility is crucial for integrated pest management (IPM). This study examined the lethal and sublethal effects of thiamethoxam on S. japonicum through three exposure routes. An acute toxicity bioassay showed that LC50 values of thiamethoxam for S. japonicum through residue contact, egg-dip, and systemic treatment were 6.65, 4.37, and 2.43 mg AI L(-1), respectively. The prey consumption of S. japonicum given different densities of B. tabaci eggs under control, discontinuous, egg-dip and systemic exposure scenarios showed a good fit to a Type II functional response. Predation of S. japonicum was most affected under systemic exposure, followed by egg-dip, and discontinuous, which was only slightly affected. In all cases tested, however, predators recovered their predation capacity rapidly, either after 24h of exposure or 24h after the end of exposure. Thiamethoxam was highly toxic to S. japonicum regardless of exposure routes. Sublethal effects of thiamethoxam applied systemically or foliar both impaired the biological control of S. japonicum on B. tabaci. Therefore, thiamethoxam should be used with caution in IPM of B. tabaci. PMID:25655818

  15. A Survey of the Insect Pests and Farmers' Practices in the Cropping of Tomato in Nigeria

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    Umeh, VC.

    2002-01-01

    Full Text Available A survey of some tomato producing areas of Nigeria indicated that the major insects attacking tomato included the fruit borer Helicoverpa armigera Hübner, the grasshopper Zonocerus variegatus L., the whitefly Bemisia tabacci Gennadius, and various species of aphids, mostly Aphis gossypii Glover. Interviews conducted to assess farmers' practices which contribute to insect damage showed that inappropriate application of insecticides and the use of wrong dosages may have contributed to insect control failures. Intercropping tomato with crops such as cereals tubers and other vegetables reduced infestation in some areas. However, most farmers' practices did not affect insect pest abundance. Insect populations and percentages of infestation were, in most cases, found to be significantly higher in Oyo state (in the rain forest agro-ecological zone than in other surveyed states located in the savannah agro-ecological zones.

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

    Directory of Open Access Journals (Sweden)

    Maria Elisa de Sena Fernandes

    2009-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Thiago Luis Martins Fanela

    2012-12-01

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

  18. LNA probes substantially improve the detection of bacterial endosymbionts in whole mount of insects by fluorescent in-situ hybridization

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    Priya Natarajan

    2012-05-01

    Full Text Available Abstract Background Detection of unculturable bacteria and their localization in the host, by fluorescent in-situ hybridization (FISH, is a powerful technique in the study of host-bacteria interaction. FISH probes are designed to target the 16 s rRNA region of the bacteria to be detected. LNA probes have recently been used in FISH studies and proven to be more efficient. To date no report has employed LNA probes for FISH detection of bacterial endosymbiont in the whole mount tissues. Further, though speculated, bacteriocytes have not been reported from males of Bemisia tabaci. Results In this study, we compared the efficiency in detecting bacteria by fluorescent DNA oligonucleotides versus modified probes containing Locked Nucleic Acid (LNA substitution in their structure. We used the insect Bemisia tabaci as the experimental material since it carried simultaneous infection by two bacteria: one a primary endosymbiont, Portiera (and present in more numbers while the other a secondary endosymbiont Arsenophonus (and present in less numbers. Thus a variation in the abundance of bacteria was expected. While detecting both the bacteria, we found a significant increase in the signal whenever LNA probes were used. However, the difference was more pronounced in detecting the secondary endosymbiont, wherein DNA probes gave weak signals when compared to LNA probes. Also, signal to noise ratio for LNA probes was higher than DNA probes. We found that LNA considerably improved sensitivity of FISH, as compared to the commonly used DNA oligonucleotide probe. Conclusion By employing LNA probes we could detect endosymbiotic bacteria in males, which have never been reported previously. We were able to detect bacteriocytes containing Portiera and Arsenophonus in the males of B. tabaci. Thus, employing LNA probes at optimized conditions will help to significantly improve detection of bacteria at the lowest concentration and may give a comprehensible depiction

  19. Spatiotemporal patterns of induced resistance and susceptibility linking diverse plant parasites.

    Science.gov (United States)

    Mouttet, Raphaëlle; Kaplan, Ian; Bearez, Philippe; Amiens-Desneux, Edwige; Desneux, Nicolas

    2013-12-01

    Induced defenses mediate interactions between parasites sharing the same host plant, but the outcomes of these interactions are challenging to predict because of spatiotemporal variation in plant responses and differences in defense pathways elicited by herbivores or pathogens. Dissecting these mediating factors necessitates an approach that encompasses a diversity of parasitic feeding styles and tracks interactions over space and time. We tested indirect plant-mediated relationships across three tomato (Solanum lycopersicum) consumers: (1) the fungal pathogen-powdery mildew, Oidium neolycopersici; (2) a sap-feeding insect-silverleaf whitefly, Bemisia tabaci; and (3) a chewing insect-the leaf miner, Tuta absoluta. Further, we evaluated insect/pathogen responses on local vs. systemic leaves and over short (1 day) vs. long (4 days) time scales. Overall, we documented: (1) a bi-directional negative effect between O. neolycopersici and B. tabaci; (2) an asymmetrical negative effect of B. tabaci on T. absoluta; and (3) an asymmetrical positive effect of T. absoluta on O. neolycopersici. Spatiotemporal patterns varied depending on the species pair (e.g., whitefly effects on leaf miner performance were highly localized to the induced leaf, whereas effects on pathogen growth were both local and systemic). These results highlight the context-dependent effects of induced defenses on a diverse community of tomato parasites. Notably, the outcomes correspond to those predicted by phytohormonal theory based on feeding guild differences with key implications for the recent European invasion by T. absoluta. PMID:23851986

  20. The intracellular bacterium Wolbachia uses parasitoid wasps as phoretic vectors for efficient horizontal transmission.

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    Muhammad Z Ahmed

    2015-02-01

    Full Text Available Facultative bacterial endosymbionts are associated with many arthropods and are primarily transmitted vertically from mother to offspring. However, phylogenetic affiliations suggest that horizontal transmission must also occur. Such horizontal transfer can have important biological and agricultural consequences when endosymbionts increase host fitness. So far horizontal transmission is considered rare and has been difficult to document. Here, we use fluorescence in situ hybridization (FISH and multi locus sequence typing (MLST to reveal a potentially common pathway of horizontal transmission of endosymbionts via parasitoids of insects. We illustrate that the mouthparts and ovipositors of an aphelinid parasitoid become contaminated with Wolbachia when this wasp feeds on or probes Wolbachia-infected Bemisia tabaci AsiaII7, and non-lethal probing of uninfected B. tabaci AsiaII7 nymphs by parasitoids carrying Wolbachia resulted in newly and stably infected B. tabaci matrilines. After they were exposed to infected whitefly, the parasitoids were able to transmit Wolbachia efficiently for the following 48 h. Whitefly infected with Wolbachia by parasitoids had increased survival and reduced development times. Overall, our study provides evidence for the horizontal transmission of Wolbachia between insect hosts by parasitic wasps, and the enhanced survival and reproductive abilities of insect hosts may adversely affect biological control programs.

  1. Detección, identificación y localización geográfica de Begomovirus que afectan al tomate en Colombia

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    Juan Carlos Vaca-Vaca

    2011-12-01

    Full Text Available Detection, identification and geographical localization of tomato-infecting Begomovirus in Colombia Título corto: Begomovirus que afectan tomate en Colombia ResumenEn la actualidad, los Begomovirus (Familia Geminiviridae se han convertido en la mayor amenaza para los cultivos de interés agrícola ubicados en las zonas tropicales y templadas del planeta. Estos virus son transmitidos por la mosca blanca Bemisia tabaci, la cual en los últimos años en Colombia ha tenido un aumento significativo en sus poblaciones y se ha asociado con la aparición de síntomas virales en cultivos de tomate. Muestras de tomate con síntomas virales típicos fueron recolectadas en las cinco principales zonas productoras de esta solanácea en el país. Los Begomovirus fueron detectados por medio de la técnica de hibridación de ácidos nucleicos tipo Dot blot así como por medio de la reacción en cadena de la polimerasa (PCR en todas las muestras colectadas. Con la excepción de un reporte previo en el Valle del Cauca, este es el primer reporte de Begomovirus afectando cultivos de tomate en los departamentos de Antioquia, Santander, Boyacá y Cundinamarca. Asimismo, es la primera vez que se informa sobre Begomovirus que afectan cultivos de tomate localizados por encima de 1500 msnm en Colombia. Palabras clave: Begomovirus, Bemisia tabaci, tomate, Dot blot, PCR. Abstract The begomoviruses (Family Geminiviridae have recently emerged as  Key words: Begomovirus, Bemisia tabaci, tomato, Dot blot, PCR. samples with typical Begomovirus symptoms were collected in five different departments, comprising the mayor tomato growing areas of the country. Begomovirus were detected by Polymerase Chain Reaction (PCR or Dot Blot Hybridization in all tomato samples collected in whole tomato growing areas of the country. With exception for Valle del Cauca, this is the first report of tomato-infecting Begomovirus in Antioquia, Santander, Boyacá and Cundinamarca departments

  2. Detecção de um begomovírus em amostras foliares de tomateiro com sondas não-radioativas Detection of a begomovirus in tomato leaf samples using non-radioactive probes

    Directory of Open Access Journals (Sweden)

    Flávio Martins Santana

    2007-02-01

    Full Text Available O aumento na ocorrência de begomoviroses (geminiviroses em tomateiros, Lycopersicon esculentum Mill., em várias regiões brasileiras, vem causando grandes prejuízos para o agronegócio de tomate, devido à ocorrência do inseto vetor, Bemisia argentifolii (Bemisia tabaci biotipo B. A diagnose é realizada em geral por "polymerase chain reaction" (PCR ou por hibridização com sondas radioativas. A PCR é um método de alta sensibilidade, porém apresenta a desvantagem da possibilidade de obtenção de resultados falso-positivos, devido a contaminações, ou falso-negativos causados por inibidores contaminantes da reação, ou pela extrema especificidade dos iniciadores. A hibridização de ácidos nucléicos com sondas radioativas tem o seu uso limitado devido à necessidade de infra-estrutura especial, treinamento de pessoal, riscos para a saúde do manipulador e demanda constante de radioquímicos. O presente trabalho tem por finalidade demonstrar a viabilidade do uso do método de hibridização com sondas não-radioativas para a detecção de um begomovírus de tomateiro do Brasil. A sensibilidade do teste foi alta, obtendo-se detecção de até 0,1fg do DNA homólogo e em extrato bruto foliar diluído até 100 vezes.Major outbreaks of tomato begomoviruses (geminiviruses in several tomato Lycopersicon esculentum Mill growing in many parts of Brazil have been imposing significant losses upon the tomato agribusiness, due to the introduction of the Bemisia argentifolii (Bemisia tabaci biotype B. Polymerase chain reaction (PCR and hybridization are generally used for diagnosis. The PCR is a detection method with high sensitivity, however it has the disadvantage of producing false-positives, due to contamination, or false-negatives caused by inhibitors or because of the high primer specifity. The use of nucleic acid hybridization with radio-labelled probes is restricted due to the requirement of special infrastructure and handling experience

  3. Distribuição espacial da meleira do mamoeiro em zonas de trópico úmido e trópico semi-árido Spatial patterns of papaya sticky disease in brazilian semi arid and rain forest regions

    OpenAIRE

    Carlos A. Vidal; Francisco F. Laranjeira; Antônio S. Nascimento; Tuffi C. Habibe

    2004-01-01

    O vírus da meleira, transmitido por Bemisia tabaci, é um dos maiores problemas da cultura do mamoeiro (Carica papaya), sendo responsável por perdas de até 100% na produção. Com o objetivo de compreender melhor sua epidemiologia e gerar subsídios para estudos da influência de fatores culturais e bioecológicos na dinâmica da doença, avaliou-se a distribuição espacial de plantas afetadas pela meleira em zonas de Trópico Úmido e Trópico Semi-árido, em 15 plantios comerciais em Eunápolis-BA e Petr...

  4. Dicty_cDB: Contig-U15678-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 00508 ) Rattus norvegicus EST, 5'-end sequence, clone etn... 66 3e-24 4 ( FC288217 ) CAGN4339.fwd CAGN Nematostella vectensis Nem...s cDNA, mRNA seq... 54 6e-20 4 ( FC250485 ) CAGH6384.fwd CAGH Nematostella vectensis Nem...74 ) A0534D09-5 NIA Mouse Mesenchymal Stem Cell cDNA L... 66 1e-10 2 ( CN662460 ) A0734D09-5 NIA Mouse Hematopoietic Stem...030-1-F12-T3_F12 Whitefly Bemisia tabaci... 50 6e-10 2 ( T34713 ) EST73889 Human Bone Homo sapiens cDNA 5' end si...ekewekahtdffeafkny deagnsrriqclkylvlacmlmlstinpfdsteakpykndpdilamtnlvmayekndiya fekilkdnrktimddpfirmyied

  5. The Role of Bacterial Chaperones in the Circulative Transmission of Plant Viruses by Insect Vectors

    Directory of Open Access Journals (Sweden)

    Murad Ghanim

    2013-06-01

    Full Text Available Persistent circulative transmission of plant viruses involves complex interactions between the transmitted virus and its insect vector. Several studies have shown that insect vector proteins are involved in the passage and the transmission of the virus. Interestingly, proteins expressed by bacterial endosymbionts that reside in the insect vector, were also shown to influence the transmission of these viruses. Thus far, the transmission of two plant viruses that belong to different virus genera was shown to be facilitated by a bacterial chaperone protein called GroEL. This protein was shown to be implicated in the transmission of Potato leafroll virus (PLRV by the green peach aphid Myzus persicae, and the transmission of Tomato yellow leaf curl virus (TYLCV by the sweetpotato whitefly Bemisia tabaci. These tri-trophic levels of interactions and their possible evolutionary implications are reviewed.

  6. Differential tolerance capacity to unfavourable low and high temperatures between two invasive whiteflies.

    Science.gov (United States)

    Xiao, Na; Pan, Li-Long; Zhang, Chang-Rong; Shan, Hong-Wei; Liu, Shu-Sheng

    2016-01-01

    Thermal response and tolerance to ambient temperature play important roles in determining the geographic distribution and seasonal abundance of insects. We examined the survival and performance, as well as expression of three heat shock protein related genes, of two species of invasive whiteflies, Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED), of the Bemisia tabaci species complex following exposure to a range of low and high temperatures. Our data demonstrated that the MED species was more tolerant to high temperatures than the MEAM1 species, especially in the adult stage, and this difference in thermal responses may be related to the heat shock protein related genes hsp90 and hsp70. These findings may assist in understanding and predicting the distribution and abundance of the two invasive whiteflies in the field. PMID:27080927

  7. Tomato yellow leaf curl virus confronts host degradation by sheltering in small/midsized protein aggregates.

    Science.gov (United States)

    Gorovits, Rena; Fridman, Lilia; Kolot, Mikhail; Rotem, Or; Ghanim, Murad; Shriki, Oz; Czosnek, Henryk

    2016-02-01

    Tomato yellow leaf curl virus (TYLCV) is a begomovirus transmitted by the whitefly Bemisia tabaci to tomato and other crops. TYLCV proteins are endangered by the host defenses. We have analyzed the capacity of the tomato plant and of the whitefly insect vector to degrade the six proteins encoded by the TYLCV genome. Tomato and whitefly demonstrated the highest proteolytic activity in the fractions containing soluble proteins, less-in large protein aggregates; a significant decrease of TYLCV proteolysis was detected in the intermediate-sized aggregates. All the six TYLCV proteins were differently targeted by the cytoplasmic and nuclear degradation machineries (proteases, ubiquitin 26S proteasome, autophagy). TYLCV could confront host degradation by sheltering in small/midsized aggregates, where viral proteins are less exposed to proteolysis. Indeed, TYLCV proteins were localized in aggregates of various sizes in both host organisms. This is the first study comparing degradation machinery in plant and insect hosts targeting all TYLCV proteins. PMID:26654789

  8. Dicty_cDB: Contig-U15422-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available terase (EC 3.1.1.7) 1 - green peach ... 171 6e-41 ( O62760 ) RecName: Full=Cholinesterase; EC=3.1.1...... 155 3e-36 FJ228228_1( FJ228228 |pid:none) Orchesella villosa acetylcholinest...... 155 3e-36 (Q6NT32) RecName: Full=Carboxylesterase 7; EC=3.1.1.1; ... 155 3e-36 FJ228227_1( FJ228227 |pid:none) Orches... |pid:none) Bemisia tabaci partial mRNA for acetylcholinesterase-like protein (ache2 gene), strain SUD-S. Le...quence BC01528... 164 1e-38 AB361595_1( AB361595 |pid:none) Cyprinus carpio ache mRNA for acet... 163 1e-38

  9. Fatores naturais que influenciam o ataque da mosca-branca em pimentão Natural factors influencing whitefly attack in sweet pepper

    Directory of Open Access Journals (Sweden)

    Germano Leão Demolin Leite

    2002-08-01

    Full Text Available Este trabalho objetivou determinar os efeitos da pluviosidade, da temperatura, da umidade relativa, dos predadores e parasitóides, da idade das plantas, dos compostos químicos foliares (cromatógrafo a gás acoplado a espectrômetro de massa - CG/EM, dos níveis de N e de K foliares sobre a intensidade do ataque de Bemisia tabaci biótipo B (Genn. (Homoptera: Aleyrodidae em pimentão (Capsicum annuum var. Myr-10. As correntes totais de íons dos picos 28,178 min. (tempo de retenção e 42,755 min. (tempo de retenção correlacionaram-se positivamente com as ninfas e adultos da mosca-branca, respectivamente, e a corrente total de íons do pico 36,352 min. (tempo de retenção correlacionou-se negativamente com ninfas deste inseto.The objective of this work was to determine the effect of rainfall, temperature, relative humidity, predators, parasitoids, plant age, leaf chemical composition (GC/MS-gas chromatographic-mass spectrometric analysis of hexane extract and levels of N and K on the intensity of attack by Bemisia tabaci biotype B (Genn. (Homoptera: Aleyrodidae on sweet pepper (Capsicum annuum var. Myr-10. Out of the four peaks detected in the hexane extract on GC/MS analysis, areas of the peak eluting at 28.178 and 42.755 min correlated positively to the nymph and adult population, respectively. The peak eluting at 36.352 min correlated negatively with the nymph population.

  10. CrypticspeciescompositionandgeneticdiversitywithinBemisiatabaci complex in soybean in India revealed by mtCOI DNA sequence

    Institute of Scientific and Technical Information of China (English)

    Prasanna H C; Kanakala S; Archana K; Jyothsna P; Varma R K; Malathi V G

    2015-01-01

    Bemisia tabaci is a cryptic species complex, causing signiifcant loss on many agricultural y important crops worldwide. Knowledge on species composition and diversity within B. tabaci complex is critical for evolving sustainable pest management strategies. Here we investigate the whitelfy species complex in soybean in major soybean growing states of India. The mitochondrial cytochrome oxidase gene subunit-1 (mtCOI) based phylogenetic relationships established using Bayesian methods indicated the existence of three cryptic species namely Asia I, Asia II 1, and Asia II 7. Al the haplotypes detected in the study could be assigned to these three cryptic species fol owing the species demarcation criteria of 3.5%divergence threshold. Of these, Asia II 1 was found to be predominant with wide spread distribution across the surveyed regions from cool temperate zones to hot and humid tropical plains. On the contrary, cryptic species Asia II 7 showed localized distribu-tion. The Asia II 1 exhibited the highest haplotype diversity and Asia I showed high level of nucleotide diversity. There was a signiifcantly high genetic differentiation among these three cryptic species. The MEAM 1, a dreadful invasive species was not detected in the specimens tested in the current study. The diversity and distribution of three cryptic species is discussed in the light of current knowledge on distribution of whitelfy species in India and yel ow mosaic disease observed during sampling survey.

  11. AVALIAÇÃO DE EXTRATOS VEGETAIS NO CONTROLE DE MOSCA BRANCA EM TOMATE

    Directory of Open Access Journals (Sweden)

    BRUNO MARCUS FREIRE VIEIRA LIMA

    2011-01-01

    Full Text Available In response to defense against herbivores, plants produce one versatile bioactive molecules synthesized in plant secondary metabolism. This paper aimed to evaluate the efficiency of plant extracts on the population level of whitefly nymphs on tomato cv. IPA 6, assess the number of fruits per treatment, fruit weight, ripeness and irregular pith. The experiment was installed in the field with the tomato crop IPA 6, block design, making use of substances extracted from plants, etanolic extract straw (Ipomoea carnea subsp. Fistulosa, etanolic extract castor (Ricinus communis L., aqueous extract tingui (Mascagnia rigida Griseb , aqueous extract Mexican poppy (Argemone mexicana L. and neem oil (Azadirachta indica A. Juss for the control of whitefly (Bemisia tabaci biotype B. The spraying was carried out by spraying, between 16 and 18 h, with an interval of seven days. Statistical analysis performed by WinStat and percentage of treatment efficiency calculated by Abbott (1925. The straw (72.41% and neem oil (67.26% were the most effective on nymphs. The number and weight of tomato fruits did not differ significantly between treatments. In relation to irregular maturation, extracts of I. carnea and M. rigida were significant. The extracts of I. carnea, M. rigida and A. Mexicana shown to be effective in controlling the pith. All plant extracts used in this experiment show efficiency on nymphs of B. tabaci.

  12. Difference in Feeding Behaviors of Two Invasive Whiteflies on Host Plants with Different Suitability: Implication for Competitive Displacement

    Directory of Open Access Journals (Sweden)

    Baiming Liu, Fengming Yan, Dong Chu, Huipeng Pan, Xiaoguo Jiao, Wen Xie, Qingjun Wu, Shaoli Wang, Baoyun Xu, Xuguo Zhou, Youjun Zhang

    2012-01-01

    Full Text Available In China, Bemisia tabaci Q (commonly known as biotype Q has rapidly displaced B (commonly known as biotype B in the past 6 years. The mechanisms underlying such phenomenon have been studied extensively in recent years; however, we have not come to a definitive conclusion yet. In the present study, the differences in host suitability between B and Q whitefly adults to five host plants (cabbage, cotton, cucumber, poinsettia, and tomato were evaluated based on their respective feeding behaviors using a direct-current electrical penetration graph (DC-EPG system. Pair-wise comparisons of B. tabaci B and Q feeding on each of the five host plants clearly indicate that Q feeds better than B on tomato, cotton and poinsettia, while B feeds better than Q on cabbage and cucumber. The EPG parameters related to both phloem and non-phloem phases confirm that cabbage and cucumber are best suited to B, while tomato, cotton, and poinsettia are best suited to Q. Our present results support the contention that host suitability and adult feeding behavior contribute to the competitive displacement of biotype B by biotype Q. The discrepancy between field (previous studies and laboratory results (this study, however, suggests that 1 whitefly displacement is apparently contributed by multiple factors; and 2 factor(s other than the host plant suitability may play a vital role in dictating the whitefly biotypes in the field.

  13. Whiteflies stabilize their take-off with closed wings.

    Science.gov (United States)

    Ribak, Gal; Dafni, Eyal; Gerling, Dan

    2016-06-01

    The transition from ground to air in flying animals is often assisted by the legs pushing against the ground as the wings start to flap. Here, we show that when tiny whiteflies (Bemisia tabaci, body length ca. 1 mm) perform take-off jumps with closed wings, the abrupt push against the ground sends the insect into the air rotating forward in the sagittal (pitch) plane. However, in the air, B. tabaci can recover from this rotation remarkably fast (less than 11 ms), even before spreading its wings and flapping. The timing of body rotation in air, a simplified biomechanical model and take-off in insects with removed wings all suggest that the wings, resting backwards alongside the body, stabilize motion through air to prevent somersaulting. The increased aerodynamic force at the posterior tip of the body results in a pitching moment that stops body rotation. Wing deployment increases the pitching moment further, returning the body to a suitable angle for flight. This inherent stabilizing mechanism is made possible by the wing shape and size, in which half of the wing area is located behind the posterior tip of the abdomen. PMID:27045098

  14. Variations in the identity and complexity of endosymbiont combinations in whitefly hosts

    Directory of Open Access Journals (Sweden)

    ShiriFreilich

    2014-07-01

    Full Text Available The target of natural selection is suggested to be the holobiont - the organism together with its associated symbiotic microorganisms. The well-defined endosymbiotic communities of insects make them a useful model for exploring the role of symbiotic interactions in shaping the functional repertoire of plants and animals. Here, we studied the variations in the symbiotic communities of the sweet potato whitefly Bemisia tabaci (Hemiptera: Aleyrodidae by compiling a dataset of over 2,000 individuals derived from several independent screenings. The secondary endosymbionts harbored by each individual were clustered into entities termed Facultative Endosymbiont Combinations (FECs, each representing a natural assemblage of co-occurring bacterial genera. The association of FECs with whitefly individuals stratified the otherwise homogeneous population into holobiont units. We both identified bacterial assemblages that are specific to whitefly groups sharing unique genetic backgrounds, and characterized the FEC variations within these groups. The analysis revealed that FEC complexity is positively correlated with both distance from the equator and specificity of the genetic clade of the host insect. These findings highlight the importance of symbiotic combinations in shaping the distribution patterns of B. tabaci and possibly other insect species.

  15. Dynamics of the endosymbiont Rickettsia in an insect pest.

    Science.gov (United States)

    Cass, Bodil N; Yallouz, Rachel; Bondy, Elizabeth C; Mozes-Daube, Netta; Horowitz, A Rami; Kelly, Suzanne E; Zchori-Fein, Einat; Hunter, Martha S

    2015-07-01

    A new heritable bacterial association can bring a fresh set of molecular capabilities, providing an insect host with an almost instantaneous genome extension. Increasingly acknowledged as agents of rapid evolution, inherited microbes remain underappreciated players in pest management programs. A Rickettsia bacterium was tracked sweeping through populations of an invasive whitefly provisionally described as the "B" or "MEAM1" of the Bemisia tabaci species complex, in the southwestern USA. In this population, Rickettsia provides strong fitness benefits and distorts whitefly sex ratios under laboratory conditions. In contrast, whiteflies in Israel show few apparent fitness benefits from Rickettsia under laboratory conditions, only slightly decreasing development time. A survey of B. tabaci B samples revealed the distribution of Rickettsia across the cotton-growing regions of Israel and the USA. Thirteen sites from Israel and 22 sites from the USA were sampled. Across the USA, Rickettsia frequencies were heterogeneous among regions, but were generally very high, whereas in Israel, the infection rates were lower and declining. The distinct outcomes of Rickettsia infection in these two countries conform to previously reported phenotypic differences. Intermediate frequencies in some areas in both countries may indicate a cost to infection in certain environments or that the frequencies are in flux. This suggests underlying geographic differences in the interactions between bacterial symbionts and this serious agricultural pest. PMID:25626393

  16. WHITEFLY- A STRONG TRANSMITTER OF PLANT VIRUSES

    Directory of Open Access Journals (Sweden)

    Suresh P. Tiwari

    2013-08-01

    Full Text Available Bemisia tabaci transmit 111 viruses. The silver leaf/sweet potato whitefly prefers 25°C to 30°C for development and rapid generation time while the greenhouse whitefly prefers temperatures of 20°C to 25°C. Eggs hatch in eight to 10 days. Resistance in B- and Q-biotype of B. tabaci appears to be linked to enhanced oxidative detoxification of neonicotinoids. Transmission efficiency from infected weeds to tomato varied from 66.7 to 100 percent, whereas, from tomato to these weeds varied from 58.3 to 83.3 percent. Increased mortality of biotype Q females and immature instars with lower rate of fecundity and progeny size compared to biotype B was recorded in such population when reared in single or mixed cultures. Two genetic types of B. tabaci were distinguished using RAPD-PCR and cytochrome oxidase I (COI gene sequence comparisons. One type was assigned to biotype B and the other was genetically dissimilar to the populations described elsewhere and was named Ms. This new genetic type forms a distinct group that is sister to two other groups, one to which the B biotype is a member and Q bioype have  similar values of intra population diversity, which were higher than the values shown by populations of biotype B. Epidemics of begomoviruses have been observed in many crops including tomato for which Tomato yellow leaf curl China virus (TYLCCNV and Tomato yellow leaf curl virus (TYLCV have been identified as two major disease-causing agents. The replication of geminiviruses induces micro-structural changes in the nucleus of the host cells. The begomovirus vector B.  tabaci is  an  insect species  complex  that  has  geographically  distinct phenotypic and genotypic variants. Criniviruses are limited to phloem and are transmitted in nature in a semipersistent manner by whiteflies. The genus Ipomovirus includes viruses that are transmitted by the whitefly B. tabaci in a semipersistent manner. Virus particles occur in the cytoplasm singly

  17. Metabolic Coevolution in the Bacterial Symbiosis of Whiteflies and Related Plant Sap-Feeding Insects.

    Science.gov (United States)

    Luan, Jun-Bo; Chen, Wenbo; Hasegawa, Daniel K; Simmons, Alvin M; Wintermantel, William M; Ling, Kai-Shu; Fei, Zhangjun; Liu, Shu-Sheng; Douglas, Angela E

    2015-09-01

    Genomic decay is a common feature of intracellular bacteria that have entered into symbiosis with plant sap-feeding insects. This study of the whitefly Bemisia tabaci and two bacteria (Portiera aleyrodidarum and Hamiltonella defensa) cohoused in each host cell investigated whether the decay of Portiera metabolism genes is complemented by host and Hamiltonella genes, and compared the metabolic traits of the whitefly symbiosis with other sap-feeding insects (aphids, psyllids, and mealybugs). Parallel genomic and transcriptomic analysis revealed that the host genome contributes multiple metabolic reactions that complement or duplicate Portiera function, and that Hamiltonella may contribute multiple cofactors and one essential amino acid, lysine. Homologs of the Bemisia metabolism genes of insect origin have also been implicated in essential amino acid synthesis in other sap-feeding insect hosts, indicative of parallel coevolution of shared metabolic pathways across multiple symbioses. Further metabolism genes coded in the Bemisia genome are of bacterial origin, but phylogenetically distinct from Portiera, Hamiltonella and horizontally transferred genes identified in other sap-feeding insects. Overall, 75% of the metabolism genes of bacterial origin are functionally unique to one symbiosis, indicating that the evolutionary history of metabolic integration in these symbioses is strongly contingent on the pattern of horizontally acquired genes. Our analysis, further, shows that bacteria with genomic decay enable host acquisition of complex metabolic pathways by multiple independent horizontal gene transfers from exogenous bacteria. Specifically, each horizontally acquired gene can function with other genes in the pathway coded by the symbiont, while facilitating the decay of the symbiont gene coding the same reaction. PMID:26377567

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  20. Pest-managing activities of plant extracts and anthraquinones from Cassia nigricans from Burkina Faso.

    Science.gov (United States)

    Georges, Kambou; Jayaprakasam, Bolleddula; Dalavoy, Sanjeev S; Nair, Muraleedharan G

    2008-04-01

    Insecticidal activity of eight plants collected from Burkina Faso was studied using mosquito (Ochlerotatus triseriatus), Helicoverpa zea and Heliothis virescens larvae and adult white fly (Bemisia tabaci). The n-hexane, ethyl acetate and methanol extracts of Pseudocedrela kotschyi, Strophantus hispidus, Securidaca longepedunculata, Sapium grahamii, Swartzia madagascariensis, Cassia nigricans, Jatropha curcas and Datura innoxia were used in this study. Extracts were tested at 250 microg/mL concentration. All three extracts of C. nigricans, J. curcas (skin and seeds) and D. innoxia exhibited 100% mortality on fourth instar mosquito (O. triseriatus) larvae. In addition, the n-hexane and ethyl acetate extracts of S. hispidus, S. longepedunculata, S. grahamii showed 100% mortality. The ethyl acetate extract of S. madagascariensis was the most active on adult white fly and exhibited 80% mortality. Extracts of all other plants exhibited 30-50% mortality on B. tabaci. In the antifeedant assays against H. zea and H. virescens, the MeOH extracts of C. nigricans, S. madagascarensis and S. hispidus were more effective against H. zea as indicated by 74% larval weight reduction as compared to the control. Since C. nigricans is commonly used in West Africa to protect grain storage from insects, we have characterized the insecticidal components present in its extract. Bioassay directed isolation of C. nigricans leaf extract yielded anthraquinones emodin, citreorosein, and emodic acid and a flavonoid, luteolin. Emodin, the most abundant and active anthraquinone in C. nigricans showed approximately 85% mortality on mosquito larvae Anopheles gambiaea and adult B. tabaci at 50 and 25 microg/mL, respectively, in 24 h. These results suggest that the extract of C. nigricans has the potential to be used as an organic approach to manage some of the agricultural pests. PMID:17478091

  1. Population dinamic of snap bean pests on four growing seasons and its influence on productive parameters / Flutuação populacional de insetos associados ao feijão-vagem c.v. UEL-1 em quatro épocas de plantio e seu efeito sobre as características produtivas

    Directory of Open Access Journals (Sweden)

    Ronaldo Mitsuo Takada

    2003-05-01

    Full Text Available Insect pests of snap beans in northern Paraná state – Brazil were monitored during four growing seasons: March – May, May – June, August – September, September – November. Adults of leafhopper (Empoasca kraemeri, whiteffly (Bemisia tabaci and corn rootworm (Diabrotica speciosa were monitored weekly using a cone trap. Leafhoppers nymphs were counted in mid height trifoliate leaves. The productive parameters evaluated in harvesting were: number of pods / plant; number of marketable pods; number of damaged pods divided in bent pods, empty pods or bored pods. Insect infestation were lower in August – September growing period, which yielded higher percent of marketable pods. The highest population of leafhopper occurred in March – May period, when the percent of curved pods were also the highest. Maximum population of whitefly occurred in early season of March – May growing period. Leaf beetle (D. speciosa population did not surpass de damage threshold in any growing period, but was higher in March – May season.Objetivou-se conhecer a flutuação populacional dos principais insetos que atacam a cultura do feijãovagem UEL-1 cultivado em diferentes épocas, e seu efeito sobre as características das vagens. Os plantios foram conduzidos na fazenda-escola da Universidade Estadual de Londrina, em quatro diferentes períodos: março-maio; maio-junho; agosto-setembro; setembro-novembro. Foram avaliados semanalmente os adultos da cigarrinha-verde (Empoasca kraemeri, mosca-branca (Bemisia tabaci e vaquinha (Diabrotica speciosa com auxílio de cone entomológico. Contagens de ninfas de E. kraemeri foram realizadas em trifólios do estrato médio da planta. Ao final de cada safra, avaliou-se o número de vagens/planta, de vagens com tamanho comercial, de vagens encurvadas, chochas e perfuradas. As menores populações de insetos ocorreram no plantio de agosto-setembro, quando obteve-se maior porcentagem de vagens com qualidade comercial

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  4. Optimización de las condiciones de inoculación por biobalística de un Begomovirus en tomate y tabaco

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    Karina López-López

    2013-12-01

    Full Text Available Optimizing conditions for biolistic inoculation of Begomovirus in tomato and tobaccoResumen: La transmisión experimental de Begomovirus es problemática. La mayoría de estos virus se pueden transmitir de planta a planta por su vector biológico, Bemisia tabaci. Las inoculaciones experimentales con mosca blanca son problemáticas debido a sus hábitos de alimentación, una planta viva infectada e instalaciones de contención para el vector. Por su parte la inoculación mecánica de Begomovirus es posible, pero generalmente a tasas bajas y no en todos los casos. Por esta razón el bombardeo de partículas (biobalística de DNA viral como una estrategia de inoculación fue desarrollada. La posibilidad de utilizar el dispositivo de mano Helios Gen System Gun (Biorad®, un equipo de biobalística, para la transmisión de un Begomovirus bipartita a plantas de tomate y tabaco fue ensayado y optimizado. Los parámetros evaluados fueron: número de disparos (1-2, presión de helio (220 y 320 psi y diámetro de las partículas de oro (0.6 y 1.6µm. Los síntomas característicos de la enfermedad viral (deformación clorosis, mosaico y de la hoja aparecieron 3 semanas después del bombardeo en las hojas jóvenes no inoculadas. La replicación del DNA viral en las plantas se confirmó por Reacción en cadena de la polimerasa. Plantas infectadas en un 100% se obtuvieron cuando en el bombardeo se emplearon partículas de oro de 1.6 µm recubiertas con DNA viral a una presión de 320psi. A nuestro entender este es el primer reporte en Colombia de la inoculación directa de plantas de tomate y tabaco con un Begomovirus bipartita usando un dispositivo portátil de biobalística.Palabras clave: geminivirus, Solanum lycopersicum, Nicotiana tabacum,  N. benthamiana, Bemisia tabaciAbstract: Experimental transmission of Begomovirus is problematic. Most Begomoviruses can be transmitted readily from plant to plant by the whitefly vector, but this also requires a

  5. Development of leaf silvering in squash cultivars infested by silverleaf whitefly Prateamento das folhas em cultivares de aboboreira infestadas por mosca-branca

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    AL Lourenção

    2011-03-01

    Full Text Available The silverleaf whitefly Bemisia tabaci biotype B is one of the most harmful insect pests for agricultural and vegetable crops. Beside the direct damage, it transmits pathogenic virus and induces plant physiological disorders, such as the squash silverleaf disorder. In this research we evaluated the development of leaf silvering in squash cultivars submitted to artificial infestation of B. tabaci biotype B. An experiment was conducted under field conditions, in Campinas, São Paulo State, Brazil, during the season 2003-2004. The germplasm (Cucurbita spp. comprised of seven cultivars of summer squash and nine of bush squash. The experiment used a complete randomized blocks design, with 16 treatments (cultivars and five replications. Each plot consisted of two plants. The artificial infestation was done when the plants emitted the third pair of leaves, by transplanting soybean plants infested with silverleaf whitefly between the squash plots. The leaf silvering was evaluated every two or three days, using a rating scale varying from 1 (no symptom to 5 (leaves completely silvered. The highest level (5.0 was observed in 'Baianinha', 'Golden Delight', 'Caravela' and 'Arlika', while 'Novita' (2.5, 'Atlas' (2.0 and 'Atlanta AG-303' (1.5 showed light symptoms, indicating that these have low sensibility to this physiological disorder.A mosca-branca (Bemisia tabaci biótipo B é uma das mais nocivas pragas da agricultura. Além de danos diretos, transmite vírus e também induz desordens fisiológicas, como o prateamento-das-folhas-da-aboboreira. No presente trabalho, avaliou-se o prateamento em folhas de cultivares de aboboreiras, submetidas à infestação artificial de B. tabaci biótipo B. Um experimento foi conduzido em condições de campo, em Campinas-SP, no ano agrícola 2003-2004, com 16 cultivares de aboboreira (Cucurbita spp., sendo sete de hábito de crescimento rasteiro e nove de moita. Utilizou-se delineamento de blocos ao acaso, com 16

  6. INCIDÊNCIA DE MOSAICO DOURADO EM FEIJOEIRO

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    SILVA, Anderson Gonçalves da

    2013-10-01

    Full Text Available Pest insects may cause damages on bean plants, and the whitefly Bemisia tabaci (biotype B stands out. The insect may transmit viruses such as the bean golden mosaic virus (BGMV, which provides economical losses that may range from 30 to 100% on the yield. Thus, this study aimed to evaluate the incidence of the golden mosaic virus on bean cultivars. The assays were set up from December 2010 to March 2011, in the Departamento de Fitossanidade at FCAV/UNESP, Campus of Jaboticabal, SP. In the assays, the cultivars were used: IAC-Formoso, IAC-Diplomata, IAC-Una, IAC- Alvorada, IAC- Harmonia, IAC- Galante, IAC-Carioca-Eté, IAC-Centauro, IAC-Carioca-Tybatã, BRS-Supremo, BRS- Requinte, BRS- Pontal, BRS- Cometa, IAPAR-81, IPR-Siriri, IPR-Eldorado, Guará, IPR-139 and Pérola. Overall, the lowest incidence of the golden mosaic were on the cultivars Pérola, IPR-Eldorado, IPR-Siriri, IPR-139, BRS-Pontal, BRS-Requinte, BRS-Supremo, IAC-Formos, IAC-Diplomata and IAC-Centauro. Insetos-praga podem causar injúrias na cultura do feijoeiro e Bemisia tabaci (biótipo B merece destaque. Este inseto pode transmitir a viroses do mosaico-dourado-do-feijoeiro (VMDF e isto provoca perdas econômicas que podem variar de 30% a 100% na produção. Dessa forma, o objetivo do presente estudo foi avaliar a incidência de mosaico dourado em cultivares de feijoeiro. Os ensaios foram instalados de dezembro de 2010 a março de 2011, no Departamento de Fitossanidade da FCAV/UNESP – Câmpus de Jaboticabal, SP. Nos testes foram utilizadas as cultivares (tratamentos: IAC-Formoso, IAC-Diplomata, IAC-Una, IAC-Alvorada, IAC-Harmonia, IAC-Galante, IAC-Carioca-Eté, IAC-Centauro, IAC-Carioca-Tybatã, BRS-Supremo, BRS-Requinte, BRS-Pontal, BRS-Cometa, IAPAR-81, IPR-Siriri, IPR-Eldorado, Guará, IPR-139 e Pérola. De maneira geral, a menor incidência de moisaco-dourado foi nas cultivares Pérola, IPR-Eldorado, IPR-Siriri, IPR-139, BRS-Pontal, BRS-Requinte, BRS-Supremo, IAC-Formos, IAC

  7. Begomovírus infectando a cultura de pimentão no estado de São Paulo Begomovirus infecting pepper crops in São Paulo state

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    Denise Nakada Nozaki

    2010-09-01

    Full Text Available Vírus do gênero Begomovirus são transmitidos por mosca-branca Bemisia tabaci G., e constituem um dos problemas fitossanitários sérios em diversas culturas. Plantas de pimentão coletadas em oito regiões do Estado de São Paulo, foram submetidas a extração de DNA total e PCR com primers universais e degenerados para begomovírus, que amplificam parte da região codificadora para a proteína capsicial. Os dados indicam a presença de begomovírus em pimentão nas cinco regiões coletadas. Análise das seqüências do DNA viral e análise filogenética revelaram identidade com dois begomovírus nativo da América. Tomato severe rugose virus - ToSRV (AY029750 e com Tomato yellow vein streak virus (ToYVSV, AY829113, espécies descritas infectando tomateiro no Brasil. A presença de begomovírus em pimentão foi verificada nas regiões de Alvinlândia, Ubirajara, Botucatu, Elias-Fausto, Paulínia, Mogi Guaçu, Paranapanema e Pirajú.Virus to the genus Begomovirus transmitted by whiteflies Bemisia tabaci G., and considered one of the most important fitossanitary problems for several cultures. Pepper plants were collected in eight the regions of São Paulo State, the extraction of total DNA and PCR were submitted with universal and degenerate primers was used to amplify partial sequences of the begomovírus coat protein gene. The data indicated the presence of begomovírus in five collected regions. DNA viral sequence analysis and phylogenetic analysis revealed identity with two native begomovírus of America. Tomato severe rugose virus - ToSRV (AY029750 and with Tomato yellow vein streak virus (ToYVSV, AY829113, described species infecting tomateiro in Brazil. The begomovírus presence in pepper plant was verified in the areas of Alvinlândia, Ubirajara, Botucatu, Elias-Fausto, Paulínia, Mogi Guaçu, Paranapanema and Pirajú.

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

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    Flávia Silva Barbosa

    2011-01-01

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

  9. Efeito do cultivo do mamoeiro (Carica papaya L. em ambiente protegido sobre a ocorrência de ácaros fitófagos e moscas-brancas Effect of papaya (Carica papaya L. cultivated in a protected environment on the occurrence of phytophagous mites and whiteflies

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    Marineide Rosa Vieira

    2004-12-01

    Full Text Available O efeito do cultivo do mamoeiro em ambiente protegido foi estudado em três condições: sem cobertura e em dois telados construídos com tela de propileno branca, com malhas de 2 x 2 mm e 2 x 1 mm. Nessa área foram feitas avaliações na cultivar Baixinho de Santa Amália, contando-se o número de plantas com sintomas de ataque recente, para o ácaro branco Polyphagotarsonemus latus, com sintomas e presença de ácaros, para o ácaro rajado Tetranychus urticae e com presença de adultos ou ninfas nas folhas, no caso das moscas-brancas Trialeurodes sp., Bemisia tabaci biótipo B e uma terceira espécie não identificada. Para moscas-brancas, também foram realizadas contagens de ninfas e exúvias em laboratório. O cultivo em ambiente protegido favoreceu a sobrevivência e o desenvolvimento populacional das espécies estudadas, sendo que algumas possíveis causas são discutidas no texto. Considerando-se que o cultivo protegido pode ser uma boa alternativa para o controle de viroses, como o mosaico do mamoeiro, problema limitante para a cultura, estratégias de manejo de pragas nesses ambientes devem ser desenvolvidas, para viabilizar o seu uso.It was measured the effect of cultivating papaya cultivar "Baixinho de Santa Amália" in a protected environment and in three situations: without shade, and under screen shades of white polyethylene mesh sizes 2 x 2 mm or 2 x 1 mm. It was registered the number of plants with symptoms of recent attacks of the broad mite (Polyphagotarsonemus latus, symptoms and presence of the two-spotted spider mite (Tetranychus urticae and the presence on leaves of adults or nymphs of whiteflies (Trialeurodes sp., Bemisia tabaci biotype B and a third unidentified species. Whitefly nymph and exuviae numbers were also counted in the laboratory. Cultivation in a protected environment favored the survival and development of the species under study, and some possible reasons for these are discussed along the text. Since

  10. Effects of food deprivation on host feeding and parasitism of whitefly parasitoids.

    Science.gov (United States)

    Zang, Lian-Sheng; Liu, Tong-Xian

    2010-06-01

    Most whitefly parasitoids kill whiteflies in one of two ways, by piercing the whitefly body with the ovipositor and laying an egg or by piercing the body and feeding on host fluids. The effects of food deprivation on host-feeding and parasitizing capacity of the whitefly parasitoids Eretmocerus melanoscutus and Encarsia formosa (Hymenoptera: Aphelinidae) were determined in this study. We investigated the effects of various food-deprivation durations (0, 3, 6, 10, and 24 h, and 20% honey solution offered) before being released on the host mortality and parasitism by these species, using fourth-instar Bemisia tabaci (Homoptera: Aleyrodidae) nymphs as test hosts. Er. melanoscutus that were food deprived for 6 h fed on more hosts than those that were food deprived for 0 and 10 h and those that were fed only on honey solution. En. formosa was less sensitive to food deprivation, there being no significant changes in host feeding and parasitism. These species' differences were further confirmed by using third instars of B. tabaci, and both parasitoid species that were food deprived for 6 h fed on more hosts and parasitized similar or more hosts than those that were not food deprived. We also confirmed that Er. melanoscutus that were food deprived for 6 h killed significantly more whiteflies by host feeding and parasitism combined than the nonfood-deprived Er. melanoscutus. However, there were no significant differences in longevity between food-deprived and nonfood-deprived parasitoids of either species. We concluded that the effectiveness of Er. melanoscutus to biological control whitefly nymphs could be improved by starving them for 6 h prior to release. PMID:20550806

  11. Formation of Stylet Sheaths in aere (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. Inhibition of α-glucosidase activity by N-deoxynojirimycin analogs in several insect phloem sap feeders.

    Science.gov (United States)

    Ya'kobovitz, Marina Katzman; Butters, Terry D; Cohen, Ephraim

    2016-02-01

    Secondary metabolites and synthetic iminosugars that structurally resemble monosaccharides are potent inhibitors of α-glucosidase activity. The enzyme is core in cleaving sucrose in phloem feeding insects and it also plays a crucial role of reducing osmotic stress via the formation of oligosaccharides. Inhibition of hydrolysis by iminosugars should result in nutritional deficiencies and/or disruption of normal osmoregulation. Deoxynojirimycin (DNJ) and 2 N-alkylated analogs [N-butyl DNJ (NB-DNJ) and N-nonyl DNJ (NN-DNJ)] were the major iminosugars used throughout the study. The extensive experiments conducted with α-glucosidase of the whitefly Bemisia tabaci indicated the competitive nature of inhibition and that the hydrophilic DNJ is a potent inhibitor in comparison to the more hydrophobic NB-DNJ and NN-DNJ compounds. The same inhibitory pattern was observed with the psyllid Cacopsylla bidens α-glucosidase. In contrast to the above pattern, enzymes of the aphids, Myzus persicae and Aphis gossypii were more sensitive to the hydrophobic iminosugars as compared to DNJ. In vivo experiments in which adult B. tabaci were fed dietary iminosugars, show that the hydrophilic DNJ was far less toxic than the lipophilic NB-DNJ and NN-DNJ. It is proposed that this pattern is attributed to the better accessibility of the hydrophobic NN-DNJ to the α-glucosidase membrane-bound compartment in the midgut. Based on the inhibitory effects of certain polyhydroxy N-alkylated iminosugars, α-glucosidase of phloem feeding hemipterans could serve as an attractive target site for developing novel pest control agents. PMID:25900765

  13. Interaction Between Bt-Transgenic Cotton and the Whitefly’s Parasitoid, Encarsia Formosa (Hymenoptera: Aphelinidae

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    Azimi Solmaz

    2014-07-01

    Full Text Available Transgenic Bt cotton developed against lepidopteran pests may not be compatible with parasitoid of secondary pests such as Bemisia tabaci which attack many plants such as cotton. In this study, the effects of Bt cotton on the demographic parameters of Encarsia formosa, parasitoid of B. tabaci were assessed. The data were analysed using the age specific, two-sex life table parameters. The results indicated that pre-adult developmental time, the total preoviposition period (TPOP and the adult preoviposition period (APOP in the Bt cotton were significantly longer than in the non-Bt cotton. Also, fecundity and body size in both lines were significantly different. The fecundity was 23.64±0.73 and 43.75±0.89 eggs/females in the Bt and non-Bt cotton, respectively. All the population parameters were affected by the Bt cotton. The intrinsic rate of increase (r was 0.15 day-1 in the non-Bt cotton but it was 0.10 day-1 in the Bt cotton. The finite rate of increase (λ was 1.11 day-1 in the non-Bt cotton whilst it was 1.08 in the Bt cotton. The net reproductive rate (R0 in the non-Bt cotton was 36.75 but in the Bt cotton these parameters showed 19.62 offspring/individual. Also, the mean generation time (T in the non-Bt and Bt cotton was 22.69 and 27.79 days, respectively. The results illustrated, that although transgenic crops are effective tools for management of the target pests, they can adversely affect, either directly or indirectly, the natural enemies dependent on these plants.

  14. The toxicity comparison and application evaluation of pyridaben to three insect pest%哒螨灵对三种害虫的毒力比较及其应用潜力评价

    Institute of Scientific and Technical Information of China (English)

    任学祥; 王开运; 左一鸣; 肖昌海; 杨焕青

    2011-01-01

    In order to extend the application scope of pyridaben, the toxicity of pyridaben to Bemisia tabaci biotype B, Laodelphax striatellus and Phyllotreta striolata were detected using the residual film and immersion methods. The results showed that pyridaben had higher toxicity than the other pesticides to adults of B. tabaci biotype B and P. striolata with LC50 O. 952 mg/L and 0. 252 mg/L, respectively. The LC50 of pyridaben to nymphs of B. tabaci biotype B was 43. 148 mg/L, the toxicity of which was lower than those of acetamiprid and imidacloprid, as high as nitenpyram, but higher than pyriproxyfen nearly one time. The LC50 of pyridaben to L. striatellus was 195. 123 mg/L, which was lower than that of chlorpyrifos, but was higher than those of acetamiprid and imidacloprid. The results showed that pyridaben had high toxicity to adults of B. tabaci biotype B and L. striatellus, to nymphs of B. tabaci and P. striolata as well. The results indicated that pyridaben was worthy to be further studied and developed.%为明确杀螨剂哒螨灵对B型烟粉虱、水稻灰飞虱和黄曲条跳甲等3种害虫的毒力和扩大其使用范围,采用玻管药膜法测定了哒螨灵等药剂对B型烟粉虱和水稻灰飞虱成虫的毒力,用浸渍法测定了哒螨灵等对B型烟粉虱若虫和黄曲条跳甲的毒力.结果显示,哒螨灵对烟粉虱成虫和水稻灰飞虱成虫的毒力最高,触杀LC50分别为0.952 mg/L和0.252 mg/L;哒螨灵对B型烟粉虱若虫的触杀LC50为43.148 mg/L,其毒力较啶虫眯和吡虫啉低,与烯啶虫胺毒力相当,但较吡丙醚毒力高近1倍;哒螨灵对黄曲条跳甲的LC50为195.123 mg/L,其毒力低于毒死蜱,但高于啶虫脒和吡虫啉.表明哒螨灵不仅对B型烟粉虱和水稻灰飞虱成虫毒力高,对烟粉虱若虫和黄曲条跳甲的毒力也较高,有进一步开发应用的潜力.

  15. Characterization of a new begomovirus and a beta satellite associated with the leaf curl disease of French bean in northern India.

    Science.gov (United States)

    Kamaal, Naimuddin; Akram, Mohammad; Pratap, Aditya; Yadav, Prashant

    2013-02-01

    Begomoviruses are emerging as serious threat to many crops throughout the world particularly in tropical and sub-tropical regions. A leaf curl disease with symptoms typical of infection by many begomoviruses was observed in French bean (Phaseolus vulgaris) at Kanpur, India, during 2010-2012. The disease caused downward leaf curling and made the plants unproductive. The disease was transmitted from infected to healthy plants through whitefly (Bemisia tabaci). The products of five samples digested with EcoRI yielded DNA fragments of about 2.7 kb. The complete sequence of the Fb1 sample comprised 2,741 nucleotides with genome organization typical of begomoviruses having two ORFs in virion-sense and five ORFs in complementary-sense separated by an intergenic region with begomovirus conserved nonanucleotide sequence, TAATATTAC. The complete DNA-A sequence homology was most closely related to Cotton leaf curl Bangalore virus with 80 % nucleotide sequence identity. Based on the demarcation criteria for identifying a begomovirus species, Fb1 is considered as a distinct begomovirus species, named French bean leaf curl virus and designated as FbLCV-[IN:Knp:12]. The complete sequence of associated satellite DNA-β comprises 1,379 nucleotides with single ORF and has 80 % identity with Papaya leaf curl beta satellite. There was no evidence of recombination in DNA-A of FbLCV and associated beta satellite DNA molecule. PMID:23054434

  16. Sweepoviruses cause disease in sweet potato and related Ipomoea spp.: fulfilling Koch's postulates for a divergent group in the genus begomovirus.

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    Helena P Trenado

    Full Text Available Sweet potato (Ipomoea batatas and related Ipomoea species are frequently infected by monopartite begomoviruses (genus Begomovirus, family Geminiviridae, known as sweepoviruses. Unlike other geminiviruses, the genomes of sweepoviruses have been recalcitrant to rendering infectious clones to date. Thus, Koch's postulates have not been fullfilled for any of the viruses in this group. Three novel species of sweepoviruses have recently been described in Spain: Sweet potato leaf curl Lanzarote virus (SPLCLaV, Sweet potato leaf curl Spain virus (SPLCSV and Sweet potato leaf curl Canary virus (SPLCCaV. Here we describe the generation of the first infectious clone of an isolate (ES:MAL:BG30:06 of SPLCLaV. The clone consisted of a complete tandem dimeric viral genome in a binary vector. Successful infection by agroinoculation of several species of Ipomoea (including sweet potato and Nicotiana benthamiana was confirmed by PCR, dot blot and Southern blot hybridization. Symptoms observed in infected plants consisted of leaf curl, yellowing, growth reduction and vein yellowing. Two varieties of sweet potato, 'Beauregard' and 'Promesa', were infected by agroinoculation, and symptoms of leaf curl and interveinal loss of purple colouration were observed, respectively. The virus present in agroinfected plants was readily transmitted by the whitefly Bemisia tabaci to I. setosa plants. The progeny virus population present in agroinfected I. setosa and sweet potato plants was isolated and identity to the original isolate was confirmed by sequencing. Therefore, Koch's postulates were fulfilled for the first time for a sweepovirus.

  17. Arthropods associated with medicinal plants in coastal South Carolina

    Institute of Scientific and Technical Information of China (English)

    ROLANDO LOPEZ; B. MERLE SHEPARD

    2007-01-01

    Arthropods were sampled from feverfew [Tanacetum parthenium (L.) SchultzBip], Echinaceapurpurea (L.) Moench, Echinaceapallida (Nutt.) Nutt., Valeriana officinalis L., and St. John's wort (Hypericum perforatum L.) during 1998-2001. In addition,arthropods were sampled on tansy (Tanacetum vulgare L.) from 2001-2004. In general,50-60 arthropod species where collected and identified among all of the medicinal plant species. Among the predators, Orius insidiosus (Say) (Hemiptera: Anthocoridae), Geocoris punctipes (Say) (Hemiptera: Lygaeidae) and spiders were most abundant from 1998-2004.The three-cornered alfalfa hopper, Spissistilus festinus (Say), was the most abundant herbivore found from 1998 to 2001. Orius insidiosus and G. punctipes were 3-4 times more abundant on T. parthenium than on any other medicinal plant species. Based on the numbers of predatory arthropods found on T. parthenium, this crop could be suitable as a companion or "banker" plant to attract and maintain populations of predators, especially O. insidiosus and G. punctipes. Whitefly nymphs attacked by predators with piercing/sucking mouthparts are easily identified using a microscope because of the general appearance of the carcass left by the predators. Thus, populations of predators on T. parthenium suppressed Bemisia tabaci populations on E. purpurea when these crops were planted as companion crops.

  18. Transgenic plants expressing the AaIT/GNA fusion protein show increased resistance and toxicity to both chewing and sucking pests.

    Science.gov (United States)

    Liu, Shu-Min; Li, Jie; Zhu, Jin-Qi; Wang, Xiao-Wei; Wang, Cheng-Shu; Liu, Shu-Sheng; Chen, Xue-Xin; Li, Sheng

    2016-04-01

    The adoption of pest-resistant transgenic plants to reduce yield losses and decrease pesticide use has been successful. To achieve the goal of controlling both chewing and sucking pests in a given transgenic plant, we generated transgenic tobacco, Arabidopsis, and rice plants expressing the fusion protein, AaIT/GNA, in which an insecticidal scorpion venom neurotoxin (Androctonus australis toxin, AaIT) is fused to snowdrop lectin (Galanthus nivalis agglutinin, GNA). Compared with transgenic tobacco and Arabidopsis plants expressing AaIT or GNA, transgenic plants expressing AaIT/GNA exhibited increased resistance and toxicity to one chewing pest, the cotton bollworm, Helicoverpa armigera. Transgenic tobacco and rice plants expressing AaIT/GNA showed increased resistance and toxicity to two sucking pests, the whitefly, Bemisia tabaci, and the rice brown planthopper, Nilaparvata lugens, respectively. Moreover, in the field, transgenic rice plants expressing AaIT/GNA exhibited a significant improvement in grain yield when infested with N. lugens. This study shows that expressing the AaIT/GNA fusion protein in transgenic plants can be a useful approach for controlling pests, particularly sucking pests which are not susceptible to the toxin in Bt crops. PMID:25641865

  19. Silverleaf whitefly induces salicylic acid defenses and suppresses effectual jasmonic acid defenses.

    Science.gov (United States)

    Zarate, Sonia I; Kempema, Louisa A; Walling, Linda L

    2007-02-01

    The basal defenses important in curtailing the development of the phloem-feeding silverleaf whitefly (Bemisia tabaci type B; SLWF) on Arabidopsis (Arabidopsis thaliana) were investigated. Sentinel defense gene RNAs were monitored in SLWF-infested and control plants. Salicylic acid (SA)-responsive gene transcripts accumulated locally (PR1, BGL2, PR5, SID2, EDS5, PAD4) and systemically (PR1, BGL2, PR5) during SLWF nymph feeding. In contrast, jasmonic acid (JA)- and ethylene-dependent RNAs (PDF1.2, VSP1, HEL, THI2.1, FAD3, ERS1, ERF1) were repressed or not modulated in SLWF-infested leaves. To test for a role of SA and JA pathways in basal defense, SLWF development on mutant and transgenic lines that constitutively activate or impair defense pathways was determined. By monitoring the percentage of SLWF nymphs in each instar, we show that mutants that activate SA defenses (cim10) or impair JA defenses (coi1) accelerated SLWF nymphal development. Reciprocally, mutants that activate JA defenses (cev1) or impair SA defenses (npr1, NahG) slowed SLWF nymphal development. Furthermore, when npr1 plants, which do not activate downstream SA defenses, were treated with methyl jasmonate, a dramatic delay in nymph development was observed. Collectively, these results showed that SLWF-repressed, JA-regulated defenses were associated with basal defense to the SLWF. PMID:17189328

  20. Silverleaf Whitefly Induces Salicylic Acid Defenses and Suppresses Effectual Jasmonic Acid Defenses1[W][OA

    Science.gov (United States)

    Zarate, Sonia I.; Kempema, Louisa A.; Walling, Linda L.

    2007-01-01

    The basal defenses important in curtailing the development of the phloem-feeding silverleaf whitefly (Bemisia tabaci type B; SLWF) on Arabidopsis (Arabidopsis thaliana) were investigated. Sentinel defense gene RNAs were monitored in SLWF-infested and control plants. Salicylic acid (SA)-responsive gene transcripts accumulated locally (PR1, BGL2, PR5, SID2, EDS5, PAD4) and systemically (PR1, BGL2, PR5) during SLWF nymph feeding. In contrast, jasmonic acid (JA)- and ethylene-dependent RNAs (PDF1.2, VSP1, HEL, THI2.1, FAD3, ERS1, ERF1) were repressed or not modulated in SLWF-infested leaves. To test for a role of SA and JA pathways in basal defense, SLWF development on mutant and transgenic lines that constitutively activate or impair defense pathways was determined. By monitoring the percentage of SLWF nymphs in each instar, we show that mutants that activate SA defenses (cim10) or impair JA defenses (coi1) accelerated SLWF nymphal development. Reciprocally, mutants that activate JA defenses (cev1) or impair SA defenses (npr1, NahG) slowed SLWF nymphal development. Furthermore, when npr1 plants, which do not activate downstream SA defenses, were treated with methyl jasmonate, a dramatic delay in nymph development was observed. Collectively, these results showed that SLWF-repressed, JA-regulated defenses were associated with basal defense to the SLWF. PMID:17189328

  1. de calda e do espectro de gotas

    Directory of Open Access Journals (Sweden)

    José Luís Aguiar Figueiredo

    2007-01-01

    Full Text Available Se evaluó la influencia de la norma de aplicación y del espectro de gotas durante la aplicación de insecticidas, en el control de la mosca blanca (Bemisia tabaci, en el cultivo de la berenjena. Los ensayos constaron de muestras de menores y adultas de la mosca blanca en los tercios cimero y mediano de la parte aérea de plantas de berenjena, a los 4,7,14 y 21 días después de la aplicación de los tratamientos y del espectro de la población de gotas obtenido durante las aplicaciones. Los tratamientos utilizados fueron resultados de la combinación del tipo de equipamiento, boquillas hidráulicas y normas de pulverización, además del testigo donde no hubo aplicación. El uso de menores normas de aplicación produjo gotas de menor tamaño y mejor cobertura, evaluadas en términos de impactos por unidad de área . El mejor control de las menores y adultas de la mosca blanca fue obtenido a través de la combinación de la mochila manual dotada de válvula de presión constante (2 bar, boquilla abanico (API 11003 y norma de pulverización de 500 L/ha.

  2. Evolutionary conservation of candidate osmoregulation genes in plant phloem sap-feeding insects.

    Science.gov (United States)

    Jing, X; White, T A; Luan, J; Jiao, C; Fei, Z; Douglas, A E

    2016-06-01

    The high osmotic pressure generated by sugars in plant phloem sap is reduced in phloem-feeding aphids by sugar transformations and facilitated water flux in the gut. The genes mediating these osmoregulatory functions have been identified and validated empirically in the pea aphid Acyrthosiphon pisum: sucrase 1 (SUC1), a sucrase in glycoside hydrolase family 13 (GH13), and aquaporin 1 (AQP1), a member of the Drosophila integral protein (DRIP) family of aquaporins. Here, we describe molecular analysis of GH13 and AQP genes in phloem-feeding representatives of the four phloem-feeding groups: aphids (Myzus persicae), coccids (Planococcus citri), psyllids (Diaphorina citri, Bactericera cockerelli) and whiteflies (Bemisia tabaci MEAM1 and MED). A single candidate GH13-SUC gene and DRIP-AQP gene were identified in the genome/transcriptome of most insects tested by the criteria of sequence motif and gene expression in the gut. Exceptionally, the psyllid Ba. cockerelli transcriptome included a gut-expressed Pyrocoelia rufa integral protein (PRIP)-AQP, but has no DRIP-AQP transcripts, suggesting that PRIP-AQP is recruited for osmoregulatory function in this insect. This study indicates that phylogenetically related SUC and AQP genes may generally mediate osmoregulatory functions in these diverse phloem-feeding insects, and provides candidate genes for empirical validation and development as targets for osmotic disruption of pest species. PMID:26896054

  3. 我国蔬菜作物重大入侵害虫发生、危害与控制%Occurrence,damage and control of important invasive insect pests on the vegetable crops in China

    Institute of Scientific and Technical Information of China (English)

    张友军; 朱国仁; 褚栋; 吴青君; 王少丽

    2011-01-01

    Vegetables are important economic crops in China. Alien invasive insect pests have caused great losses to vegetable production in China in recent years. This review used three kinds of important invasive insects on vegetable crops in China as examples, namely Bemisia tabaci, Frankliniella occidentalis and Liriomyza, and summarized the important achievements in this area, including discoveries of alien insects, species identification, distribution and dispersal, outbreak mechanisms, and technical system for sustainable control of these pests.%蔬菜是我国重要的经济作物,近年来外来入侵害虫给我国蔬菜生产造成了重大损失.本文以严重危害我国蔬菜作物的3类重大入侵害虫-烟粉虱、西花蓟马和斑潜蝇为例,从入侵昆虫的发现、种群鉴定、分布扩散趋势及其规律、灾变机制以及可持续治理技术体系的研究与应用等方面概述了我国蔬菜入侵害虫研究的主要成就.

  4. Assessment of pest and pesticide trends in vegetable crops in united arab emirates and sultanate of oman

    International Nuclear Information System (INIS)

    A preliminary survey on pesticide uses in 40 vegetable-growing farms representing different agricultural areas in Oman and the UAE, twenty farms from each country, revealed that all the vegetable farms used pesticides for crop protection. Among the major insect-pests, white flies (Bemisia tabaci), leafminers (Liriomyza trifolii), melon fruit flies (Bactrocera ciliatus), aphids (Aphis spp.) and tobacco leafworm (Spodoptera litteralis) were recorded in Omani farms. In the UAE, white flies, leafminers, cutworms (Agrotis ypsilan), tomato fruitworms (Helicoverpa armigera) and eggplant fruitworms (Leucinodes orbonalis) were the 5 top insect-pests. Among the plant diseases, powdery mildew (Erysiphe spp.), blight (Alternaria spp.), damping off (Pythium spp.), leafspot (Alternaria spp.) and mosaic (CMV) Were major cause of vegetable diseases in Omani farms; whereas, damping off (Pythium aphanidermatum), downy mildew (Pseudoperonspora cubensis), early blight (Alternaria solani), septoria leaf spot (Septoria lycopersici) and anthracnose rip rot (colletotrichum spp.) were the most predominant diseases encountered in most UAE farms. Among the most commonly used pesticides, 29 insecticides, 16 fungicides and 3 herbicides were used by the vegetable farmers. Around 55% of Omani farms used routine application of pesticides, irrespective of the pest presence. Whereas, in the UAE, most farmers started to spray pesticides at 6-20% pest (insect, disease and weeds) infection. Over 65 of the farms, in both the countries, received chemical pest management information from the sales representatives. (author)

  5. Identification of a novel DNA molecule associated with Tobacco leaf curl virus

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A circular DNA molecule, designated as DNAβ, was identified in tobacco plants infected with Tobacco leaf curl virus (TLCV) isolates Y5 and Y8 by PCR using primers based on the conserved region of the two reported DNAβsequences of whitefly-transmitted geminiviruses (WTGs). The complete nucleotide sequences of DNAβof Y5 and Y8 (TLCV DNAβ) were determined. Y5 DNAβcomprises 1333 nucleotides encoding 8 predicted ORFs with 4 ORFs in virion-sense DNA and 4 ORFs in complementary-sense DNA; Y8 DNAβconsists of 1338 nucleotides encoding 7 predicted ORFs with 4 ORFs in virion-sense DNA and 3 ORFs in complementary-sense DNA. TLCV DNAβhas little sequence homology to DNA-A of TLCV, except that it shares conserved TAATATTAC loop sequence with TLCV DNA-A. Sequence comparison showed that Y5 DNAβshared 85% sequence homology with Y8 DNAβ, and both Y5 DNAβand Y8 DNAβhad relatively low sequence identity (51%-65%) with the reported DNAβmolecules associated with Ageratum yellow vein virus and Cotton leaf curl virus. The immunotrapping PCR and whitefly transmission tests showed that DNAβmolecule could be encapsidated in virus particle and transmitted by Bemisia tabaci. This is the first report of DNAβassociated with WTGs in China.

  6. 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.

  7. 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

    2015-10-01

    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. PMID:26516898

  8. Enhanced methanol production in plants provides broad spectrum insect resistance.

    Directory of Open Access Journals (Sweden)

    Sameer Dixit

    Full Text Available Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR and spectra showed up to 16 fold higher methanol as compared to control wild type (WT plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid and Bemisia tabaci (whitefly, respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants.

  9. Pepper (Capsicum annuum) Is a Dead-End Host for Tomato yellow leaf curl virus.

    Science.gov (United States)

    Morilla, G; Janssen, D; García-Andrés, S; Moriones, E; Cuadrado, I M; Bejarano, E R

    2005-09-01

    ABSTRACT Tomato yellow leaf curl (TYLC) is one of the most devastating pathogens affecting tomato (Lycopersicon esculentum) worldwide. The disease is caused by a complex of begomovirus species, two of which, Tomato yellow leaf curl Sardinia virus (TYLCSV) and Tomato yellow leaf curl virus (TYLCV), are responsible for epidemics in Southern Spain. TYLCV also has been reported to cause severe damage to common bean (Phaseolus vulgaris) crops. Pepper (Capsicum annuum) plants collected from commercial crops were found to be infected by isolates of two TYLCV strains: TYLCV-Mld[ES01/99], an isolate of the mild strain similar to other TYLCVs isolated from tomato crops in Spain, and TYLCV-[Alm], an isolate of the more virulent TYLCV type strain, not previously reported in the Iberian Peninsula. In this work, pepper, Nicotiana benthamiana, common bean, and tomato were tested for susceptibility to TYLCV-Mld[ES01/99]and TYLCV-[Alm] by Agrobacterium tumefaciens infiltration, biolistic bombardment, or Bemisia tabaci inoculation. Results indicate that both strains are able to infect plants of these species, including pepper. This is the first time that infection of pepper plants with TYLCV clones has been shown. Implications of pepper infection for the epidemiology of TYLCV are discussed. PMID:18943307

  10. Genetic Study of Resistance to Begomovirus on Chili Pepper by Hayman’s Diallel Analysis

    Directory of Open Access Journals (Sweden)

    Dwi Wahyuni Ganefianti

    2015-01-01

    Full Text Available Genetic study of resistance to  Begomovirus  is required in plant breeding program to obtain  a resistance cultivar. Diallel analysis was used to evaluate the genetic parameters in early generation for Begomovirus resistance and agronomic characters. Fourty two  hybrids and 7 selfed families generated from a full diallel cross of seven parental lines varying in Begomovirus resistance and yield potential were allotted in a randomized complete block design with three replications. Virus infection was made by inoculating ‘Segunung’ isolate from infected plant using Bemisia tabaci as the vector.  Results showed that disease intensity, types of symptoms and fruit number were controlled by genes interaction.  Fruit weight was controlled by additive gene actions, whereas incubation period were controlled by dominant gene actions.   Disease intensity, types of symptoms and incubation period showed over-dominant gene actions towards lower intensity and longer incubation period respectively. The broad sense and narrow sense heritability for all characteristics are classified as moderate to high.

  11. Comparative transcriptome analysis of Arabidopsis thaliana infested by diamond back moth (Plutella xylostella larvae reveals signatures of stress response, secondary metabolism, and signalling

    Directory of Open Access Journals (Sweden)

    Aeschliman Dana S

    2008-04-01

    Full Text Available Abstract Background Plants are exposed to attack from a large variety of herbivores. Feeding insects can induce substantial changes of the host plant transcriptome. Arabidopsis thaliana has been established as a relevant system for the discovery of genes associated with response to herbivory, including genes for specialized (i.e. secondary metabolism as well as genes involved in plant-insect defence signalling. Results Using a 70-mer oligonulceotide microarray covering 26,090 gene-specific elements, we monitored changes of the Arabidopsis leaf transcriptome in response to feeding by diamond back moth (DBM; Plutella xylostella larvae. Analysis of samples from a time course of one hour to 24 hours following onset of DBM feeding revealed almost three thousand (2,881 array elements (including 2,671 genes with AGI annotations that were differentially expressed (>2-fold; p[t-test] Pieris rapae, Frankliniella occidentalis, Bemisia tabaci,Myzus persicae, and Brevicoryne brassicae. Conclusion Arabidopsis responds to feeding DBM larvae with a drastic reprogramming of the transcriptome, which has considerable overlap with the response induced by other insect herbivores. Based on a meta-analysis of microarray data we identified groups of transcription factors that are either affected by multiple forms of biotic or abiotic stress including DBM feeding or, alternatively, were responsive to DBM herbivory but not to most other forms of stress.

  12. Suscetibilidade de genótipos de feijão ao vírus-do-mosaico-dourado

    Directory of Open Access Journals (Sweden)

    Lemos Leandro Borges

    2003-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a suscetibilidade de diversos genótipos de feijão ao vírus-do-mosaico-dourado (VMDF, transmitido pela mosca branca (Bemisia tabaci. A semeadura foi realizada na época da seca e das águas, com e sem aplicação do inseticida granulado Aldicarb (3,0 kg ha-1 do i.a. no sulco de semeadura. O delineamento experimental utilizado foi o de blocos casualizados disposto em esquema fatorial 14x2, representado por genótipos e inseticida, respectivamente, com quatro repetições. A maior infestação de mosca-branca e incidência do vírus ocorreu na época da seca, causando prejuízos à produção do feijoeiro. Os genótipos apresentaram diferentes graus de suscetibilidade ao vírus e ao inseto vetor. Os genótipos mais tolerantes foram IAPAR 57, IAPAR 65, IAPAR 72, Ônix, Aporé e 606 (5(214-17. A aplicação do inseticida sistêmico controla o vetor em ambas as épocas de cultivo, proporcionando aumentos da produtividade.

  13. Differential profiles of direct and indirect modification of vector feeding behaviour by a plant virus.

    Science.gov (United States)

    He, Wen-Bo; Li, Jie; Liu, Shu-Sheng

    2015-01-01

    Plant viruses interact with their insect vectors directly and indirectly via host plants, and this tripartite interaction may produce fitness benefits to both the vectors and the viruses. Our previous studies show that the Middle East-Asia Minor 1 (MEAM1) species of the whitefly Bemisia tabaci complex improved its performance on tobacco plants infected by the Tomato yellow leaf curl China virus (TYLCCNV), which it transmits, although virus infection of the whitefly per se reduced its performance. Here, we use electrical penetration graph recording to investigate the direct and indirect effects of TYLCCNV on the feeding behaviour of MEAM1. When feeding on either cotton, a non-host of TYLCCNV, or uninfected tobacco, a host of TYLCCNV, virus-infection of the whiteflies impeded their feeding. Interestingly, when viruliferous whiteflies fed on virus-infected tobacco, their feeding activities were no longer negatively affected; instead, the virus promoted whitefly behaviour related to rapid and effective sap ingestion. Our findings show differential profiles of direct and indirect modification of vector feeding behaviour by a plant virus, and help to unravel the behavioural mechanisms underlying a mutualistic relationship between an insect vector and a plant virus that also has features reminiscent of an insect pathogen. PMID:25567524

  14. Cellular and molecular remodelling of a host cell for vertical transmission of bacterial symbionts

    Science.gov (United States)

    Luan, Jun-Bo; Shan, Hong-Wei; Isermann, Philipp; Huang, Jia-Hsin; Lammerding, Jan; Liu, Shu-Sheng; Douglas, Angela E.

    2016-01-01

    Various insects require intracellular bacteria that are restricted to specialized cells (bacteriocytes) and are transmitted vertically via the female ovary, but the transmission mechanisms are obscure. We hypothesized that, in the whitefly Bemisia tabaci, where intact bacteriocytes (and not isolated bacteria) are transferred to oocytes, the transmission mechanism would be evident as cellular and molecular differences between the nymph (pre-adult) and adult bacteriocytes. We demonstrate dramatic remodelling of bacteriocytes at the developmental transition from nymph to adulthood. This transition involves the loss of cell–cell adhesion, high division rates to constant cell size and onset of cell mobility, enabling the bacteriocytes to crawl to the ovaries. These changes are accompanied by cytoskeleton reorganization and changes in gene expression: genes functioning in cell–cell adhesion display reduced expression and genes involved in cell division, cell motility and endocytosis/exocytosis have elevated expression in adult bacteriocytes, relative to nymph bacteriocytes. This study demonstrates, for the first time, how developmentally orchestrated remodelling of gene expression and correlated changes in cell behaviour underpin the capacity of bacteriocytes to mediate the vertical transmission and persistence of the symbiotic bacteria on which the insect host depends. PMID:27358364

  15. Differential temporal changes of primary and secondary bacterial symbionts and whitefly host fitness following antibiotic treatments.

    Science.gov (United States)

    Zhang, Chang-Rong; Shan, Hong-Wei; Xiao, Na; Zhang, Fan-Di; Wang, Xiao-Wei; Liu, Yin-Quan; Liu, Shu-Sheng

    2015-01-01

    Where multiple symbionts coexist in the same host, the selective elimination of a specific symbiont may enable the roles of a given symbiont to be investigated. We treated the Mediterranean species of the whitefly Bemisia tabaci complex by oral delivery of the antibiotic rifampicin, and then examined the temporal changes of its primary symbiont "Candidatus Portiera aleyrodidarum" and secondary symbiont "Ca. Hamiltonella defensa" as well as host fitness for three generations. In adults treated with rifampicin (F0), the secondary symbiont was rapidly reduced, approaching complete disappearance as adults aged. In contrast, the primary symbiont was little affected until later in the adult life. In the offspring of these adults (F1), both symbionts were significantly reduced and barely detectable when the hosts reached the adult stage. The F1 adults laid few eggs (F2), all of which failed to hatch. Mating experiments illustrated that the negative effects of rifampicin on host fitness were exerted via female hosts but not males. This study provides the first evidence of differential temporal reductions of primary and secondary symbionts in whiteflies following an antibiotic treatment. Studies that disrupt functions of bacterial symbionts must consider their temporal changes. PMID:26510682

  16. No cross-resistance between imidacloprid and pymetrozine in the brown planthopper: status and mechanisms.

    Science.gov (United States)

    Yang, Yuanxue; Huang, Lixin; Wang, Yunchao; Zhang, Yixi; Fang, Siqi; Liu, Zewen

    2016-06-01

    Cross-resistance between insecticides, especially from different groups, can be extremely unpredictable, and it has been a serious concern in pest control. Pymetrozine has been widely used to control Nilaparvata lugens with the suspension of imidacloprid for the resistance, and N. lugens has showed obvious pymetrozine resistance in recent years. To investigate the possible cross-resistance between imidacloprid and pymetrozine is very important to avoid the adverse effects on resistance development and pest control. Bioassays of two field populations in five consecutive years showed that imidacloprid resistance decreased greatly, while pymetrozine resistance increased significantly. The synergist piperonyl butoxide (PBO) could synergize both imidacloprid and pymetrozine in all field populations, which indicated the importance of P450s in the resistance to two insecticides. Imidacloprid resistance was reported to be associated with two P450s, CYP6AY1 and CYP6ER1, which could metabolize imidacloprid efficiently. However, the recombinant proteins of these two P450s did not show any enzymatic activity to metabolize pymetrozine. The pymetrozine susceptibility did not change when CYP6AY1 and CYP6ER1 mRNA levels were reduced by RNA interference (RNAi), although which could obviously decrease imidacloprid resistance. In vivo and in vitro studies provided evidences to demonstrate that there was no cross-resistance between imidacloprid and pymetrozine in N. lugens, which was different from the findings in Bemisia tabaci. PMID:27155488

  17. Insect stings to change gear for healthy plant: Improving maize drought tolerance by whitefly infestation.

    Science.gov (United States)

    Park, Yong-Soon; Ryu, Choong-Min

    2016-05-01

    Since plants first appeared about 1.1 billion years ago, they have been faced with biotic and abiotic stresses in their environment. To overcome these stresses, plants developed defense strategies. Accumulating evidence suggests that the whitefly [Bemisia tabaci (Genn.)] affects the regulation of plant defenses and physiology. A recent study demonstrates that aboveground whitefly infestation positively modulates root biomass and anthocyanin pigmentation on brace roots of maize plants (Zea mays L.). In agreement with these observations, indole-3-acetic acid (IAA) and jasmonic acid (JA) contents and the expression of IAA- and JA-related genes are higher in whitefly-infested maize plants than in non-infected control plants. Interestingly, the fresh weight of whitefly-infested maize plants is approximately 20% higher than in non-infected control plants under water stress conditions. Further investigation has revealed that hydrogen peroxide (H2O2) accumulates in whitefly-infested maize plants after water stoppage. Taken together, these results suggest that activation of phytohormones- (i.e., IAA and JA) and H2O2-mediated maize signaling pathways triggered by aboveground whitefly infestation promotes drought resistance. They also provide an insight into how inter-kingdom interactions can improve drought tolerance in plants. PMID:27164447

  18. Use of Posttranscription Gene Silencing in Squash to Induce Resistance against the Egyptian Isolate of the Squash Leaf Curl Virus.

    Science.gov (United States)

    Taha, Omnia; Farouk, Inas; Abdallah, Abdelhadi; Abdallah, Naglaa A

    2016-01-01

    Squash leaf curl virus (SqLCV) is a bipartite begomovirus affecting squash plants. It is transmitted by whitefly Bemisia tabaci biotype B causing severe leaf curling, vein banding, and molting ending by stunting. In this study full-length genomic clone of SqLCV Egyptian isolated and posttranscriptional gene silencing (PTGS) has been induced to develop virus resistance. The Noubaria SqLCV has more than 95% homology with Jordon, Israel, Lebanon, Palestine, and Cairo isolates. Two genes fragment from SqLCV introduced in sense and antisense orientations using pFGC5049 vector to be expressed as hairpin RNA. The first fragment was 348 bp from replication associated protein gene (Rep). The second fragment was 879 bp representing the full sequence of the movement protein gene (BC1). Using real-time PCR, a silencing record of 97% has been recorded to Rep/TrAP construct; as a result it has prevented the appearance of viral symptoms in most tested plants up to two months after infection, while construct containing the BC1 gene scored a reduction in the accumulation of viral genome expression as appearing in real-time PCR results 4.6-fold giving a silencing of 79%, which had a positive effect on symptoms development in most tested plants. PMID:27034922

  19. Glucose concentration alters dissolved oxygen levels in liquid cultures of Beauveria bassiana and affects formation and bioefficacy of blastospores.

    Science.gov (United States)

    Mascarin, Gabriel Moura; Jackson, Mark A; Kobori, Nilce Naomi; Behle, Robert W; Dunlap, Christopher A; Delalibera Júnior, Ítalo

    2015-08-01

    The filamentous fungus Beauveria bassiana is an economically important pathogen of numerous arthropod pests and is able to grow in submerged culture as filaments (mycelia) or as budding yeast-like blastospores. In this study, we evaluated the effect of dissolved oxygen and high glucose concentrations on blastospore production by submerged cultures of two isolates of B. bassiana, ESALQ1432 and GHA. Results showed that maintaining adequate dissolved oxygen levels coupled with high glucose concentrations enhanced blastospore yields by both isolates. High glucose concentrations increased the osmotic pressure of the media and coincided with higher dissolved oxygen levels and increased production of significantly smaller blastospores compared with blastospores produced in media with lower concentrations of glucose. The desiccation tolerance of blastospores dried to less than 2.6 % moisture was not affected by the glucose concentration of the medium but was isolate dependent. Blastospores of isolate ESALQ1432 produced in media containing 140 g glucose L(-1) showed greater virulence toward whitefly nymphs (Bemisia tabaci) as compared with blastospores produced in media containing 40 g glucose L(-1). These results suggest a synergistic effect between glucose concentration and oxygen availability on changing morphology and enhancing the yield and efficacy of blastospores of B. bassiana, thereby facilitating the development of a cost-effective production method for this blastospore-based bioinsecticide. PMID:25947245

  20. Effect of neem seed kernel and handal extracts on muskmelon pest complex

    International Nuclear Information System (INIS)

    Cucumis melo (var ananas) was grown during the autumn and winter seasons of 1996/97 at Shambat. The efficacy of three neem (azadirachta indica A. Juss) seed kernel (NSK) extracts and one handal (citrullus colocynthis) fruit-extract (HFE) were tested against pests-complex and natural enemies associated with this crop. Malathion was used as a standard treatment. All extracts significantly reduced infestations of major pests, especially bemisia tabaci (genn), aphis gossypii (glov) and liriomyza spp, compared to untreated control. The results were always comparable to, or even better than those of malathion NSK extracts residual affect extended up to 10 days, which is longer than that of HFE. The latter seems to be attractive to epilachna elaterii at the applied dosage rate. All extracts showed delayed effect on the populations of this pest towards the end of the season. All treatments, except HFE, significantly reduced the damage by dacus ciliatus (Lw). No adverse effects on natural enemies, viz chrysopids, syrphids, and coccinellids, were detectable as a result of using plant extracts.(Author)