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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. Genetic differentiation of Bemisia tabaci (Gennadius)(Hemiptera: Aleyrodidae) biotype Q based on mitochondrial DNA markers

    Institute of Scientific and Technical Information of China (English)

    Dong Chu; Fang-Hao Wan; Yun-Li Tao; Guo-Xia Liu; Zhong-Xue Fan; Yu-Ping Bi

    2008-01-01

    In the present study, genetic differentiation of Bemisia tabaci (Gennadius)biotype Q was analyzed based on mitochondrial cytochrome oxidase I (mt COI) gene sequence. The results showed that B. tabaci biotype Q could be separated into two subclades,which were labeled as subclades Q1 and Q2. Subclade Q1 was probably indigenous to the regions around the Mediterranean area and subclade Q2 to Israel or Cyprus. It was because B. tabaci was composed of several genetically distinct groups with a strong geographical association between more closely related biotypes. Not all of the B. tabaci biotype Q in the non-Mediterranean countries come from the same regions. Until now, all B. tabaci biotype Q in China were grouped into subclade Q1. The B. tabaci biotype Q introduced into the US included both subclades Q1 and Q2. The genetic structure analysis showed higher genetic variation of subclade Q1 than that of subclade Q2.

  3. Sequence Analysis of mtDNA COIGene and Molecular Phylogeny of Different Geographical Populations of Bemisia tabaci (Gennadius)

    Institute of Scientific and Technical Information of China (English)

    CHU Dong; ZHANG You-jun; CONG Bin; XU Bao-yun; WU Qing-jun; ZHU Guo-ren

    2005-01-01

    Bemisia tabaci(Gennadius) is a serious pest in many cropping systems worldwide and occurs in different biotypes. The mtDNA COI gene of the 12 Bemisia tabaci (Gennadius) populations from different regions and countries were analyzed.Based on mtDNA COI sequences, their biotypes were characterized and phylogenetic relationships among these populations were established with the method of UPGMA. The results indicated the genetic similarity between those populations from Beijing, Zhengzhou, Zaozhuang, Nanjing, Shanghai, Haikou, and the B-biotype populations from California, Texas, Arizona reached 99.8-100%, which meant the nation-wide infested populations of B. tabaci in China in recent years were B-biotypes. Another population collected from Kunming of Yunnan Province showed very high similarity with Q-biotype B. tabaci from Spain and Morocco, which meant the Kunming population was Q-biotype. This is the first report on the invasion of Q-biotype into China.

  4. 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.

  5. 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)

  6. 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...

  7. 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.

  8. Identification of Chinese populations of Bemisia tabaci (Gennadius) by analyzing ribosomal ITS1 sequence

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Spreading of Bemisia tabaci B biotype has had a large impact on the production of vegetables, ornamental and fiber crops in many countries of the world since the 1990s. This study analyzes the ribosomal ITS1 sequence (~520 bp) to distinguish genetic difference of B. tabaci from representative different geographical populations in China. Phylogenetic analysis shows that populations of B.tabaci from Beijing and Shandong Province are of biotype B, and populations of B.tabaci from sweet potato in Fujian Province and pumpkin in Guangxi, China, belong to two different non-B biotypes and have a geographical origin of Asia.

  9. 烟粉虱暴发成因及其治理技术研究%Outbreak Reason of Cotton Whitefly [Bemisia Tabaci(Gennadius)]and its Integrated Pest Measure

    Institute of Scientific and Technical Information of China (English)

    慕卫; 刘峰; 刘海涛

    2003-01-01

    The reason of cotton whitefly [ Bemisia tabaci ( Gennadius) ] happened heavily in China in recent years was analyzed from its biology characteristic, host range, crop culture and environment situation, control measure. At last, integrated pest measure for control cotton whiteflywas clarified.

  10. Comparative Analysis of Population Genetic Structure in Bemisia tabaci (Gennadius) Biotypes B and Q Based on ISSR Marker

    Institute of Scientific and Technical Information of China (English)

    CHU Dong; WAN Fang-hao; XU Bao-yun; WU Qing-jun; ZHANG You-jun

    2008-01-01

    Bemisia tabaci (Gennadius) biotypes B and Q are two invasive biotypes in the species complex. The comparison of the population genetic structure of the two biotypes is of significance to show their invasive mechanism and to their control. The intersimple sequence repeats (ISSR) marker was used to analyze the 16 B-biotype populations and 4 Q-biotype populations worldwide with a Trialeurodes vaporariorum population in Shanxi Province, China, and a B. tabaci non-B/Q-biotype population in Zhejiang Province, China, was used as control populations. The analysis of genetic diversity showed that the diversity indexes of biotype Q including Nei's gene diversity index, Shannon informative index, and the percentage of polymorphic loci were higher than those of biotype B. The high genetic diversity of biotype Q might provide the genetic basis for the excellent ecological adaptation. Cluster analysis suggested that the ISSR could not be used in the phylogenetic analysis though it could easily distinguish the biotypes of B. tabaci. The difference of the population genetic structure between the biotype B and the biotype Q exists based on the ISSR marker. Meanwhile, the results suggested that the molecular marker has its limitation in the phylogenetic analysis among the biotypes of B. tabaci.

  11. Enhancement of Phenylalanine Ammonia Lyase, Polyphenoloxidase, and Peroxidase in Cucumber Seedlings by Bemisia tabaci(Gennadius) (Hemiptera: Aleyrodidae) Infestation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this study, the activities of phenylalanine ammonia lyase (PAL), polyphenoloxidase (PPO), and peroxidase (POD) were assayed in cucumber seedlings (Cucumis sativus L.) at 0, 6, 12, 24, 48, 72, and 96 h after they were infested by Bemisia tabaci (Gennadius) using spectrophotometric analysis. The results indicated that herbivore infestation increased the activities of PAL, PPO, and POD. The enzymes showed different activity levels at different times after the infestation. The PAL activity reached the first high peak by 23.1% at 6 h and the highest peak by 29.1% at 48 h compared to the control. The PPO activity reached the first high peak by 22.7% at 6 h and the highest peak by 52.6% at 24 h, and the POD activity reached the highest peak by 213.2% at 6 h and another higher peak value by 135.2% at 96 h. The results suggest that the enhanced activities of the enzymes may contribute to bioprotection of cucumber plants against B. Tabaci infestation.

  12. Induced changes in the antioxidative compounds of Vigna mungo genotypes due to infestation by Bemisia tabaci (Gennadius).

    Science.gov (United States)

    Taggar, Gaurav Kumar; Gill, Ranjit Singh; Gupta, Anil Kumar; Singh, Sarvjeet

    2014-11-01

    Antioxidative compounds were quantified from the leaves of nine black gram (Vigna mungo (L.) Hepper) genotypes over a period of two years, for potential whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleryrodidae) resistance. Oviposition preference, nymphal and adult development were evaluated under screen-house conditions. Biochemical analysis revealed that higher per cent increase in the total phenol and o-dihydroxy phenol contents both at 30 and 50 days after sowing was evident in moderately resistant genotypes NDU 5-7 (49.6 and 50.8%, respectively) and KU 99-20 (47.8 and 50.8%, respectively) under whitefly stress conditions as compared to non-stressed plants. Tannin and flavonol contents in leaves increased to varying degrees (up to 11.1 and 7.1%, respectively) in resistant plants after whitefly infestation, indicating that the changes in tannin and flavonol contents were closely associated with the resistance to whitefly. Correlation studies relating leaf content of black gram antioxidative compounds from different genotypes with whitefly population were also worked out. Total phenols (r = -0.71 & -0.88), o- dihydroxy phenols (r = -0.56 & -0.76), flavonols (r = -0.80 & -0.81) and tannins (r= -0.16 & -0.26) showed significant negative correlation with whitefly population (nymphs and adults) suggesting that enhanced level of these biochemicals may contribute to bioprotection of black gram plants against B. tabaci infestation. Comparatively higher level of resistance in genotype NDU 5-7 and KU 99-20 can serve as base for genetic improvement of black gram, focusing on the development of resistant varieties to B. tabaci.

  13. 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...... (Manihot esculenta Crantz) – one of the most important food security crops in sub-Saharan Africa. After the outbreak and spread of a severe form of CMD from Uganda to several East and African countries, the production of cassava has been impaired causing severe yield loss resulting in food shortages...... the use of field survey and molecular approaches aimed to fill the knowledge gap to this effect and sought (i) to assess the genetic diversity and distribution of cassava-associated B. tabaci in CMD pandemicaffected areas in Tanzania and to establish the association of a distinct B. tabaci genotype...

  14. 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 ...

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  16. 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

  17. 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

  18. 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.

  19. 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)

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

    Science.gov (United States)

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

    2012-10-01

    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 plants. The enzymes showed different activity levels at different times after the infestation. The results indicated that in general, whitefly infestation increased the activities of peroxidase and decreased the catalase activity. Resistant genotypes NDU 5-7 and KU 99-20 recorded higher peroxidase and catalase activities at 30 and 50 DAS under whitefly-stress conditions as compared with non-stressed plants. The results suggest that the enhanced activities of the enzymes may contribute to bioprotection of black gram plants against B. tabaci infestation. The potential mechanisms to explain the correlation of resistance to whitefly in black gram genotypes with higher activities of oxidative enzymes are also discussed.

  1. Biological parameters of Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae) on Jatropha gossypiifolia, commercial (Manihot esculenta) and wild cassava (Manihot flabellifolia and M. carthaginensis) (Euphorbiaceae).

    Science.gov (United States)

    Carabalí, Arturo; Belloti, Anthony C; Montoya-Lerma, James

    2010-01-01

    Bemisia tabaci (Gennadius) is one of the most important pests of cassava in Africa and several countries of Asia due to the damage caused by direct feeding, the excretion of honeydew, and its capacity as a vector of cassava mosaic geminivirus. There is a general consensus that B. tabaci is a complex of morphologically indistinguishable populations with different biotypes. In the Americas, the polyphagous biotype B does not appear to feed on cassava. Recent studies indicate that it is possible, however, for biotype B to gradually adapt to cassava using phylogenetically related hosts. Therefore, the possibility that some wild species of cassava constitute intermediate hosts in the adaptation process may lead to the establishment of biotype B on commercial varieties of Manihot esculenta. In here, we evaluated Jatropha gossypiifolia, two wild species of cassava (Manihot flabellifolia and M. carthaginensis) and a commercial cassava variety (MCol 2063) as hosts of biotype B. The highest oviposition rate (2.7 eggs /two days) occurred on M. esculenta, although the development time (44 d) was the longest when compared to M. carthaginensis and J. gossypiifolia. About 60% of the population could reproduce on the wild cassava species vs. 55% on J. gossypiifolia and 27.5% on the commercial variety. Our data suggest that J. gossypiifolia is a suitable host and the wild species M. carthaginensis can constitute a potential intermediate host in the adaptation of biotype B to commercial varieties of cassava.

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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

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

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    Reihaneh Barati

    2013-01-01

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

  11. 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...

  12. 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...

  13. 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

  14. 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

  15. New records of entomopathogenic fungi infecting Bemisia tabaci and Trialeurodes vaporariorum, pests of horticultural crops, in Argentina

    Science.gov (United States)

    The whiteflies (Hemiptera: Aleyrodidae) Bemisia tabaci (Gennadius), and Trialeurodes vaporariorum (Westwood) are major crop pests throughout the world. Although extensive research about biological control of whitefly has been conducted towards these insect's parasitoids and predators, several entom...

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

    Science.gov (United States)

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

  17. A distinct Bemisia tabaci (Gennadius) (Hemiptera: Sternorrhyncha: Aleyrodidae) genotype cluster is associated with the epidemic of severe cassava mosaic virus disease in Uganda.

    Science.gov (United States)

    Legg, J P; French, R; Rogan, D; Okao-Okuja, G; Brown, J K

    2002-07-01

    During the 1990s, an epidemic of cassava mosaic virus disease caused major losses to cassava production in Uganda. Two factors associated with the epidemic were the occurrence of a novel recombinant begomovirus, EACMV-Ug, and unusually high populations of the whitefly vector, Bemisia tabaci. Here we present molecular evidence for the occurrence of two cassava-colonizing B. tabaci genotype clusters, Ug1 and Ug2, one of which, Ug2, can be consistently associated with the CMD epidemic in Uganda at the time of collection in 1997. By contrast, a second genotype cluster, Ug1, only occurred 'at' or 'ahead of' the epidemic 'front', sometimes in mixtures with Ug2. Comparison of mitochondrial cytochrome oxidase I gene sequences for Ug1 and Ug2 and well-studied B. tabaci reference populations indicated that the two Ugandan populations exhibited approximately 8% divergence, suggesting they represent distinct sub-Saharan African lineages. Neither Ugandan genotype cluster was identified as the widely distributed, polyphagous, and highly fecund B biotype of Old World origin, with which they both diverged by approximately 8%. Within genotype cluster divergence of Ug1 at 0.61 +/- 0.1% was twice that of Ug2 at 0.35 +/- 0.1%. Mismatch analysis suggested that Ug2 has undergone a recent population expansion and may be of nonUgandan origin, whereas Ug1 has diverged more slowly, and is likely to be an indigenous genotype cluster.

  18. Biotypes Identification and Damage Analysis of Bemisia tabaci ( Gennadius)in Shaanxi Area%陕西地区烟粉虱生物型的鉴定及其危害分析

    Institute of Scientific and Technical Information of China (English)

    赵瑞华; 邓振山; 贺晓龙

    2015-01-01

    To evaluate main biotypes and damage of Bemisia tabaci( Gennadius)in Shaanxi area,we analyzed the ex-tent of damage through investigation and identified the variety of biotypes in Shaanxi main host plants by mtDNA COI sequences of Bemisia tabaci. The sequence analysis results indicated that the B and Q biotypes B. tabaci co-existed in Shaanxi area,and B biotype B. tabaci was 78. 85%. The results showed that B biotype still was the main biotype ,but Q biotype spreads widely in Shaanxi area and may replace B biotype as a major crop pest in Shaanxi ar-ea. B. tabaci damaged crops seriously such as tobacco,sweet pepper,tomato of solanaceae and cucumber,pumpkin of cucurbitaceae. But the plants of cruciferae were damaged lightly,and damagous to potato of solanaceae and cow-pea,peas of leguminosae were lightest.%为探明陕西地区烟粉虱的危害及主要生物型,实地调查了陕西地区主要农作物上烟粉虱的危害状况与发生程度,并利用mtDNACOI基因测序方法,对陕西地区烟粉虱的生物型组成进行了分析鉴定.同源性分析结果表明,B型和Q型烟粉虱是陕西地区烟粉虱种群的主要生物型,其中B型占所测总样本的78. 85%,表明陕西省烟粉虱主要生物型仍是B型,但Q型种群比例在增长,不排除有取代B型成为陕西地区烟粉虱主要危害类型的趋势.在陕西地区烟粉虱主要危害的植物是茄科的烟草、甜椒、番茄以及葫芦科的黄瓜、西葫芦,而十字花科植物普遍受害较轻,茄科的马铃薯和豆科的豇豆、豌豆受害最轻.

  19. 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

  20. 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...

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

    Science.gov (United States)

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

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

    OpenAIRE

    Nombela, Gloria; 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...

  3. Genetic Differentiation of Different Geographical Populations of Bemisia tabaci (Gennadius) Complex%烟粉虱复合种不同地理种群的遗传分化

    Institute of Scientific and Technical Information of China (English)

    褚栋; 刘国霞; 范仲学; 陶云荔; 张友军

    2006-01-01

    烟粉虱Bemisia tabaci(Gennadius) 是由具有遗传分化的不同地理种群组成的复合种.本文介绍了烟粉虱不同地理种群遗传分化的最新研究进展,并在世界各国对烟粉虱核糖体ITS1(rDNA ITS1)、线粒体COI(mtDNA COI)基因大量测序的基础上,进一步分析了烟粉虱不同地理种群的遗传分化.根据mtDNA COI和rDNA ITS1基因序列分析的结果,烟粉虱不同地理种群可分为5组,即亚洲组(Asia group)、美洲组(America group)、非洲组(Africa group)、澳洲组(Australia group)、B型/地中海/中东/北非/Ms型组(Biotype B/Mediterranean/Middle Eastern/Northern Africa/Biotype Ms group);此外,还包括3个没有特定组的种群,即乌干达(Uganda)、科特迪瓦(Ivory Coast和台湾(Taiwan)种群.地理隔离可能是造成烟粉虱不同地理种群遗传分化的最重要驱动力.许多具有入侵性或生物学优势的烟粉虱种群随着人类活动而传入新的地区,造成了严重的经济损失.有必要加强烟粉虱生物型的监测,遏制已入侵烟粉虱种群的蔓延,防止新的具有潜在危险性的烟粉虱种群传入中国.

  4. 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

  5. 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.

  6. A new silverleaf inducing biotype of Bemisia tabaci (Hemiptera: Aleyrodidae) Ms, indigenous for the islands of the South West Indian Ocean

    NARCIS (Netherlands)

    Delatte, H.; Reynaud, B.; Granier, M.; Thornary, L.; Lent, van J.W.M.; Goldbach, R.W.; Peterschmitt, M.

    2005-01-01

    Following the first detection of tomato yellow leaf curl virus (TYLCV) from Réunion (700 km east of Madagascar) in 1997 and the upsurge of Bemisia tabaci (Gennadius) on vegetable crops, two genetic types of B. tabaci were distinguished using RAPD¿PCR and cytochrome oxidase I (COI) gene sequence comp

  7. 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...

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    BACKGROUND: The two common whitefly species, Bemisia tabaci (Gennadius) MEAM1 and Trialeurodes vaporariorum (Westwood), often co-occur on their host plants. The effect of host plant occupation by one species on later-arriving conspecific individuals or on the other competing species was examined...

  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. Interspecific interactions between Bemisia tabaci biotype B and Trialeurodes vaporariorum (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Zhang, Gui-Fen; Li, Dong-Chao; Liu, Tong-Xian; Wan, Fang-Hao; Wang, Jin-Jun

    2011-02-01

    Bemisia tabaci (Gennadius) biotype B and Trialeurodes vaporariorum (Westwood) are invasive whitefly species that often co-occur on greenhouse-grown vegetables in northern China. Although B. tabaci biotype B has been present in China for a relatively short period of time, it has become dominant over T. vaporariorum. We studied the interspecific competitive interactions between the two species in single or mixed cultures at 24 ± 1 °C, 40 ± 5% RH, and L14:D10 h photoperiod. Female longevity on tomato was not significantly different between species, but B. tabaci reproduced 4.3 to 4.9 fold more progeny. The ratio of female to male progeny in both instances was greater for B. tabaci. When cultured on tomato, cotton, and tobacco, B. tabaci developed 0.8, 3.3, and 4.7 d earlier in single culture, and 1.8, 3.9, and 4.3 d earlier in mixed culture. B. tabaci displaced T. vaporariorum in four, five and six generations when the initial ratios of B. tabaci to T. vaporariorum were 15:15, 20:10, or 10:20 on tomato. Populations of B. tabaci were 2.3 fold higher than that of T. vaporariorum on tomato plants for seven consecutive generations in single culture. B. tabaci performed better in development, survival, fecundity, and female ratio. We conclude that B. tabaci could displace T. vaporariorum in as short as four generations in a controlled greenhouse environment when they start at equal proportions. Warmer greenhouse conditions and an increase in total greenhouse area could be contributing factors in the recent dominance of B. tabaci.

  13. 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.

  14. 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.

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

    Science.gov (United States)

    Bonato, Olivier; Couton, Louise; Fargues, Jacques

    2006-08-01

    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, young or late instars) were assessed. M. caliginosus preferred older nymphs of B. tabaci than any other stage. It also chose T. vaporariorum over B. tabaci, unless the latter consisted of > 75% of the available prey. These results suggested that M. caliginosus might interfere with parasitoids such as Encarsia, Eretmocerus, or Amitus spp. because all three species emerge from the host pupal case. Furthermore, in mixed infestations, M. caliginosus preference for T. vaporariorum might either negatively affect the control of B. tabaci, or, contrarily, enhance the predator population, before a B. tabaci outbreak occurs in the greenhouse.

  16. Improved DNA barcoding method for Bemisia tabaci and related Aleyrodidae: development of universal and Bemisia tabaci biotype-specific mitochondrial cytochrome c oxidase I polymerase chain reaction primers.

    Science.gov (United States)

    Shatters, Robert G; Powell, Charles A; Boykin, Laura M; Liansheng, He; McKenzie, C L

    2009-04-01

    Whiteflies, heteropterans in the family Aleyrodidae, are globally distributed and severe agricultural pests. The mitochondrial cytochrome c oxidase I (mtCOI) sequence has been used extensively in whitefly phylogenetic comparisons and in biotype identification of the agriculturally important Bemisia tabaci (Gennadius) whitefly. Because of the economic importance of several whitefly genera, and the invasive nature of the B and the Q biotypes of Bemisia tabaci, mtCOI sequence data are continually generated from sampled populations worldwide. Routine phylogenetic comparisons and biotype identification is done through amplification and sequencing of an approximately 800-bp mtCOI DNA fragment. Despite its routine use, published primers for amplification of this region are often inefficient for some B. tabaci biotypes and especially across whitefly species. Through new sequence generation and comparison to available whitefly mtCOI sequence data, a set of polymerase chain reaction (PCR) amplification primers (Btab-Uni primers) were identified that are more efficient at amplifying approximately 748 bp of the approximately 800-bp fragment currently used. These universal primers amplify an mtCOI fragment from numerous B. tabaci biotypes and whitefly genera by using a single amplification profile. Furthermore, mtCOI PCR primers specific for the B, Q, and New World biotypes of B. tabaci were designed that allow rapid discrimination among these biotypes. These primers produce a 478-, 405-, and 303-bp mtCOI fragment for the B, New World, and Q biotypes, respectively. By combining these primers and using rapid PCR and electrophoretic techniques, biotype determination can be made within 3 h for up to 96 samples at a time.

  17. Suitability changes with host leaf age for Bemisia tabaci B biotype and Trialeurodes vaporariorum.

    Science.gov (United States)

    Zhang, Gui-Fen; Wan, Fang-Hao

    2012-10-01

    The suitability of tomato leaves of different ages for Bemisia tabaci (Gennadius) B biotype and Trialeurodes vaporariorum (Westwood) was characterized by development time, stage-specific survival, sex ratio, longevity, and fecundity. Three categories of leaf ages were tested (young: expanding leaves <2 wk old; mature: fully expanded, 4-5-wk-old leaves; old: fully expanded, 6-7-wk-old leaves). There was no significant variation in the duration of development of the two species among the three classes of leaf ages, but total survival and ratio of females to males on mature and old leaves were higher than on young leaves. For egg hatch, the reverse tendency was found. Longevity of both species was higher on mature than on young leaves, and fecundity during the first 2 wk of adult life was higher on mature than on young or old leaves. The B. tabaci B biotype developed faster through the quiescent fourth nymphal instar, had higher ratio of females to males, survived longer, and produced more eggs (in the first 2 wk of adult life) than T. vaporariorum on leaves of the same age; although on young leaves, B. tabaci B biotype survivorship was lower than that of T. vaporariorum. The index of host suitability of B. tabaci B biotype was higher on mature and old leaves than on young leaves. In T. vaporariorum, no such differences were found among these three leaf ages. The results could provide some cues why B. tabaci B biotype is spreading so vigorously.

  18. 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.

  19. 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.

  20. Effects of host plants on insecticide susceptibility and carboxylesterase activity in Bemisia tabaci biotype B and greenhouse whitefly, Trialeurodes vaporariorum.

    Science.gov (United States)

    Liang, Pei; Cui, Jian-Zhou; Yang, Xiu-Qing; Gao, Xi-Wu

    2007-04-01

    Bemisia tabaci (Gennadius) biotype B and the greenhouse whitefly, Trialeurodes vaporariorum (Westwood), have become serious pests of cotton and vegetable crops in China since the early 1990s. In recent years, however, B. tabaci have broken out more frequently and widely than have T. vaporariorum. The B. tabaci biotype B has also developed higher resistance to several insecticides. Here, the effects of four different host plants on the insecticide susceptibility of B. tabaci biotype B and T. vaporariorum have been compared. The LC(50) values of imidacloprid, abamectin, deltamethrin and omethoate in T. vaporariorum reared on cucumber were significantly higher than those in B. tabaci (the LC(50) values in T. vaporariorum were respectively 3.13, 2.63, 2.78 and 6.67 times higher than those in B. tabaci). On the other hand, the B. tabaci population reared on cotton was more tolerant to all four insecticides tested than the T. vaporariorum population from the same host, especially to abamectin (up to 8.4-fold). The effects of the four host plants on the activity of carboxylesterase (CarE) in B. tabaci biotype B and T. vaporariorum were also compared. The results showed that, although the CarE activity of B. tabaci and T. vaporariorum varied depending on the host plants, the B. tabaci population possessed significantly higher CarE activity than the T. vaporariorum population reared on the same host plant. This was especially so on cucumber and cotton, where the CarE activities of the B. tabaci population were over 1.6 times higher than those of T. varporariorum. The frequency profiles for this activity in B. tabaci and T. vaporariorum populations reared on same host plant were apparently different.

  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. 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.

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

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    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.

  4. Fitness of Encarsia sophia(Hymenoptera: Aphelinidae)parasitizing Trialeurodes vaporariorum and Bemisia tabaci (Hemiptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    Chen Luo; Tong-Xian Liu

    2011-01-01

    Fitness and efficacy of Encarsia sophia(Girault & Dodd)(Hymenoptera:Aphelinidae)as a biological control agent was compared on two species of whitefly(Hemiptera: Aleyrodidae)hosts,the relatively smaller sweetpotato whitefly,Bemisia tabaci(Gennadius)biotype 'B',and the larger greenhouse whitefly,Trialeurodes vaporariorum(Westwood).Significant differences were observed on green bean(Phaseolus vulgaris L.)in the laboratory at 27± 2℃,55% ± 5% RH,and a photoperiod of 14 : 10 h(L : D).Adult parasitoids emerging from T.vaporariorum were larger than those emerging from B.tabaci,and almost all biological parameters of E.sophia parasitizing the larger host species were superior except for the developmental times of the parasitoids that were similar when parasitizing the two host species.Furthermore,parasitoids emerging from T.vaporariorum parasitized more of these hosts than did parasitoids emerging from B.tabaci.We conclude that E.sophia reared from larger hosts had better fitness than from smaller hosts.Those from either host also preferred the larger host for oviposition but were just as effective on smaller hosts.Therefore,larger hosts tended to produce better parasitoids than smaller hosts.

  5. 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

  6. 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.

  7. 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.

  8. 西藏发现Q型烟粉虱%New record of theBemisia tabaci Q biotype in Tibet, China

    Institute of Scientific and Technical Information of China (English)

    卢少华; 白润娥; 翟卿; 王保海; 闫凤鸣

    2016-01-01

    Objectives]To determine the biotypes ofBemisia tabaci (Gennadius) found in the Tibet Autonomous Region, China. [Methods] Morphological characteristics of whiteflies were observed under a 3D digital microscope, and the biotype of whiteflies collected from Lhasa, Tibet, identified on the basis of variation in the molecular marker mtCOⅠ. [Results] Analysis of variation in themtCOⅠmolecular marker shows that whiteflies collected in Tibet were of the Q biotype. [Conclusion]The results of both morphological identification and molecular analysis show that the whiteflies collected in Lhasa, Tibet Autonomous Region, were of theBemisia tabaci Q biotype. This is the first report of theBemisia tabaci Q biotype from the Tibet Autonomous Region.%【目的】调查西藏自治区烟粉虱Bemisia tabaci(Gennadius)的发生情况。【方法】从西藏拉萨采集到烟粉虱各个虫态,采用3D数码显微镜观察所采集烟粉虱的形态特征,利用 mtCOⅠ分子标记检测烟粉虱的生物型。【结果】明确并详细描述了烟粉虱各形态特征,mtCOⅠ分子标记检测显示西藏采集到的烟粉虱为Q生物型。【结论】在形态学鉴定的基础上,分子生物学鉴定该粉虱为Q型烟粉虱,这是Q型烟粉虱在西藏自治区发生的首次报道。

  9. 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.

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

    Science.gov (United States)

    Van Ekert, Evelien; Chauvigné, François; Finn, Roderick Nigel; Mathew, Lolita G; Hull, J Joe; Cerdà, Joan; Fabrick, Jeffrey A

    2016-10-01

    The Middle East-Asia Minor 1 (MEAM1) whitefly, Bemisia tabaci (Gennadius) is an economically important pest of food, fiber, and ornamental crops. This pest has evolved a number of adaptations to overcome physiological challenges, including 1) the ability to regulate osmotic stress between gut lumen and hemolymph after imbibing large quantities of a low nitrogen, sugar-rich liquid diet; 2) the ability to avoid or prevent dehydration and desiccation, particularly during egg hatching and molting; and 3) to be adapted for survival at elevated temperatures. One superfamily of proteins involved in the maintenance of fluid homeostasis in many organisms includes the aquaporins, which are integral membrane channel proteins that aid in the rapid flux of water and other small solutes across biological membranes. Here, we show that B. tabaci has eight aquaporins (BtAqps), of which seven belong to the classical aquaporin 4-related grade of channels, including Bib, Drip, Prip, and Eglps and one that belongs to the unorthodox grade of aquaporin 12-like channels. B. tabaci has further expanded its repertoire of water channels through the expression of three BtDrip2 amino-terminal splice variants, while other hemipteran species express amino- or carboxyl-terminal isoforms of Drip, Prip, and Eglps. Each BtAqp has unique transcript expression profiles, cellular localization, and/or substrate preference. Our phylogenetic and functional data reveal that hemipteran insects lost the classical glp genes, but have compensated for this by duplicating the eglp genes early in their evolution to comprise at least three separate clades of glycerol transporters. PMID:27491441

  11. 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.

  12. 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.

  13. Whitefly Bemisia tabaci (Homoptera: Aleyrodidae) infestation on cassava genotypes grown at different ecozones in Nigeria.

    Science.gov (United States)

    Ariyo, O A; Dixon, A G O; Atiri, G I

    2005-04-01

    Large-scale screening of cassava, Manihot esculenta Crantz, genotypes for resistance to infestation by whitefly Bemisia tabaci Gennadius, the vector of cassava mosaic geminiviruses, is limited. A range of new cassava elite clones were therefore assessed for the whitefly infestation in the 1999/2000 and 2000/2001 cropping seasons in experimental fields of International Institute of Tropical Agriculture, Ibadan, Nigeria. On each scoring day, between 0600 and 0800 hours when the whiteflies were relatively immobile, adult whitefly populations on the five topmost expanded leaves of cassava cultivars were counted. All through the 6-mo scoring period, there was a highly significant difference in whitefly infestation among the new cassava elite clones. Vector population buildup was observed in Ibadan (forest-savanna transition zone) and Onne (humid forest), 2 mo after planting (MAP). Mean infestation across cassava genotypes was significantly highest (16.6 whiteflies per plant) in Ibadan and lowest in Zaria (0.2). Generally, whitefly infestation was very low in all locations at 5 and 6 MAP. During this period, cassava genotypes 96/1439 and 91/02324 significantly supported higher infestations than other genotypes. Plants of 96/1089A and TMS 30572 supported the lowest whitefly infestation across cassava genotypes in all locations. The preferential whitefly visitation, the differences between locations in relation to whitefly population, cassava mosaic disease, and the fresh root yield of cassava genotypes are discussed.

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

    Directory of Open Access Journals (Sweden)

    Andrew G. S. Cuthbertson

    2015-02-01

    Full Text Available 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 widespread and problematic with this species. As a result, this continues to pose problems for eradication strategies. The current study investigates the efficacy of Tri-Tek (a petroleum horticultural oil awaiting UK registration and the fungus Beauveria bassiana to act as control agents against Mediterranean species in UK glasshouses. Tri-Tek provided 100% egg mortality compared to 74% for B. bassiana. When tested against second instar larvae, mortalities of 69% and 65% respectively were achieved. Both products can be successfully “tank-mixed”. A tank-mix application provided 95.5% mortality of second instar larvae under glasshouse conditions. The potential integration of both products into current Bemisia eradication strategies in UK glasshouses is discussed.

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

    Science.gov (United States)

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

    2013-06-01

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

  16. Development and reproduction of ‘B' biotype Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) on four ornamentals

    Institute of Scientific and Technical Information of China (English)

    LILIN; SHUN-XIANGREN

    2005-01-01

    Effects of four commercial ornamentals on the development, survivorship and reproduction of the whitefly B biotype Bemisia tabaci (Gennadius) were studied in the laboratory (temperature 26 ±1℃; relative humidity 75%-90%; L: D 14:10). The total survivorship from egg to adult on hibiscus (Hibiscus rosa-sinensis L.), poinsettia (Euphorbia pulcherrima Will), cottonrose hibiscus (Hibiscus mutabilis L.) and variegated leafcroton (Codiaeum variegatum ‘Aucubaefolium') were 33.69%, 40.55%, 79.11%, and 29.39%,respectively. The developmental periods from egg to adult varied from 23.12 days on cottonrose hibiscus to 32.13 days on hibiscus. The average longevity of adult females ranged from 6.87 days on variegated leafcroton to 21.07 days on poinsettia. The average numbers of eggs laid per female were 9.20, 25.13, 54.45, and 26.79 on the above respective hosts. The intrinsic rates of natural increase (rm) for B biotype B. tabaci on cottonrose hibiscus was the highest. Based on life table analyses of whitefly populations, cottonrose hibiscus was the most suitable host for B biotype B. tabaci in this study.

  17. The integrated use of chemical insecticides and the entomopathogenic nematode, Steinernema carpocapsae(Nematoda: Steinernematidae), for the control of sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    Andrew G. S. Cuthbertson; James J. Mathers; Phil Northing; Anthony J. Prickett; Keith F. A. Waiters

    2008-01-01

    The integration of chemical insecticides and infective juveniles of the entomopathogenic nematode Steinernema carpocapsae (Wesier) (Nematoda:Steinernematidae), to control second instars of the sweetpotato whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) was investigated. Using a sand bioassay, the effects of direct exposure of S. carpocapsae for 24 h to field rate dilutions of four insecticides (spiromesifen, thiacloprid, imidaeloprid and pymetrozine) on infectivity to Galleria rnellonella larvae were tested. Although all chemicals tested, except spiromesifen, produced acceptable nematode infectivity rates, they were all significantly less than the water control. The effect of insecticide treatment (dry residues of spiromesifen, thiacloprid and pymetrozine and soil drench of imidacloprid) on the efficacy of the nematode against B. tabaci was also investigated. Nematodes in combination with thiacloprid and spiromesifen gave higher B.tabaci mortality (86.5% and 94.3% respectively) compared to using nematodes alone (75.2%) on tomato plants. There was no significant difference in B. tabaci mortality when using the chemicals imidacloprid, pymetrozine and spiromesifen in conjunction with nematodes compared to using the chemicals alone. However, using thiaeloprid in combination with the nematodes produced significantly higher B. tabaci mortality than using the chemical alone. The integration of S. carpocapsae and these chemical agents into current integrated pest management programmes for the control of B. tabaci is discussed.

  18. The effects of potassium levels in tobacco plants on the development, survival and host selectivity of Q-biotype Bemisia tabaci (Gennadius)%烟草钾营养对Q型烟粉虱发育、存活和寄主选择性的影响

    Institute of Scientific and Technical Information of China (English)

    金鹏; 林华峰; 李毅; 李茂业; 陈德鑫

    2014-01-01

    Objectives In order to provide a theoretical foundation for the control of Q-biotype Bemisia tabaci by regulating the nutrition of its host plant, the effects of potassium levels in tobacco plants on host selection, development and survival rate of Q-biotype B. tabaci were examined. [Methods] The host selection, development and survival rate of Q-biotype B. tabaci were investigated on water-cultured tobacco plants provided with five different concentrations of potassium:K1 (0 mmol/L), K2 (3 mmol/L), K3 (6 mmol/L), K4 (9 mmol/L) and K5 (12 mmol/L). [Results] Host preference, developmental duration and survival rate of Q-biotype B. tabaci on tobacco plants treated with different concentrations of potassium were significantly different. Relative feeding and oviposition preferences were K2>K1>K3>K4>K5, while the length of developmental duration from egg to adult on different plants was K5 (22.54 d)>K4 (21.96 d)>K1 (20.92 d)>K2 (20.32 d)>K3 (20.23 d). Survival rates from egg to adult on different plants were K3 (88.72%)>K2 (85.05%)>K1 (82.03%)>K4 (77.02%)> K5 (69.92%). [Conclusion] Q-biotype B. tabaci populations can be managed by regulating the potassium content of tobacco plants.%明确烟草钾营养对Q型烟粉虱Q-biotype Bemisia tabaci(Gennadius)的寄主选择性、发育和存活的影响,旨在为通过调节寄主植物营养控制Q型烟粉虱种群数量提供理论依据。水培法培养经K1(0 mmol/L)、K2(3 mmol/L)、K3(6 mmol/L)、K4(9 mmol/L)及K5(12 mmol/L)5个不同钾浓度处理的烟草,研究Q型烟粉虱在不同处理烟草上的寄主选择性、发育历期和存活率。Q型烟粉虱在不同钾浓度处理烟草上的寄主选择性、发育历期和存活率均有显著差异,取食和产卵偏好性顺序为K2>K1>K3>K4>K5,卵到成虫羽化发育历期顺序为K5(22.54 d)>K4(21.96 d)>K1(20.92 d)>K2(20.32 d)>K3(20.23 d),卵到成虫羽化存活率顺序为K3(88.72%)>K2(85.05%

  19. B型烟粉虱和温室白粉虱热激蛋白90基因(hsp90)的全长cDNA克隆与系统发育分析%cDNA cloning and phylogenetic analysis of the heat shock protein 90 gene (hsp90) in two whiteflies,Bemisia tabaci (Gennadius) biotype B and Trialeurodes vaporariorum (Westwood) (Homoptera:Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    余昊; 万方浩

    2009-01-01

    B型烟粉虱Bemisia tabaci (Gennadius) biotype B和温室白粉虱Trialeurodes vaporariorum均为全球普遍发生的重要害虫.本研究以其他昆虫热激蛋白90基因(hsp90)保守区域设计兼并引物扩增两种粉虱hsp90中间片段,然后利用RACE技术获得全长cDNA.温室白粉虱hsp90全长cDNA的开放性阅读框2 166 bp,编码722个氨基酸;烟粉虱hsp90全长cDNA的开放性阅读框2 160 bp,编码720个氨基酸.两种粉虱HSP90的完整氨基酸序列相似性高达92.94%,并均具有定义HSP90家族签名序列的5个氨基酸保守区域和末尾基序"MEEVD".通过real-time PCR技术,探测到两个基因在mRNA水平上皆能高温诱导表达.采用昆虫纲所有完整HSP90氨基酸序列进行Kimura双参数遗传距离分析并构建NJ进化树,结果显示hsp90在昆虫纲低级阶元水平和高级阶元水平系统进化上能得到一个较理想结果.本研究结果为B型烟粉虱和温室白粉虱抗逆适应性研究提供基础,并进一步验证保守的功能基因hsp90可以作为研究生物系统发育的手段之一.

  20. 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

  1. Genetic mutations associated with chemical resistance in the cytochrome P450 genes of invasive and native Bemisia tabaci (Hemiptera: Aleyrodidae) populations in China

    Institute of Scientific and Technical Information of China (English)

    Bao-Li Qiu; Li Liu; Xiao-Xi Li; Vartika Mathur; Zhen-Qiang Qin; Shun-Xiang Ren

    2009-01-01

    Bemisia tabaci (Gennadius) is a species complex, and its two most damaging biotypes B and Q are globally distributed pests. Despite increasing biological and economic impacts, little is known about the evolutionary mechanisms that favor their competfion with native populations. Here, we investigated the genetic mutations in the P450 gene of the invasive B, Q biotypes and the native Cv population. Four mutations associated with chemical resistance, Pro-Leu, Ala-Ser, Ser-Phe and Trp-Leu, were found in the cytochrome P450 CYP6C and CYP9F genes of the B and Q biotypes. Bioassay results also revealed that both the B and Q biotypes have about 12-47 times more resistance to acephate, betacypermethrin, methomyl, and 5-7 times more resistance to imidacloprid insecticide than Cv population. Our results provide a molecular approach for better understanding and monitoring the pesticide resistances of invasive and native B. tabaci populations in China.

  2. 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

  3. Inundative field releases and evaluation of three predators for Bemisia tabaci (Hemiptera: Aleyrodidae) management in three vegetable crops

    Institute of Scientific and Technical Information of China (English)

    Alvin M. Simmons; Shaaban Abd-Rabou

    2011-01-01

    The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is a global pest on numerous crops, including vegetables. Weekly inundative releases of a coccineUid predator (Coccinella undecimpunctata L. [Coleoptera: Coccinellidae]), a common green lacewing predator (Chrysoperla carnea Stephen [Neuroptera: Chrysopidae]), and a mirid predator (Macrolophus caliginosus [Wagner] [Hemiptera: Miridae]) were independently made in three vegetable crops (cabbage [Brassica oleracea var. capitata L.],cucumber [Cucumis sativus L.], and squash [Cucurbita pepo L.]) for the management of the sweetpotato whitefly. Approximately 1 million to 2.5 million larvae or nymphs of each predator were released in the vegetable crops during 20 weeks. Whitefly populations were reduced by ≈ 25%-45% during most of the season in each crop where each predator was released. The effect of each predator was similar on whitefly population reduction. Late in the season (October) when whitefly populations were low, generally no benefit was obtained from releasing the predators. Numbers of predators recovered during sampling in all crops were greatest for C. carnea, but this corresponded with the fact that more individuals of this predator were released than any other predator in the experiment. These results help define the utility of these natural enemies for managing B. tabaci in vegetable crops.

  4. 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.

  5. 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...

  6. Transient receptor potential is essential for high temperature tolerance in invasive Bemisia tabaci Middle East Asia minor 1 cryptic species.

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    Zhi-Chuang Lü

    Full Text Available Temperature is an important factor in affecting population dynamics and diffusion distribution of organisms. Alien species can successfully invade and colonize to various temperature environments, and one of important reasons is that alien species have a strong resistance to stress temperature. Recently, researchers have focused on the mechanisms of temperature sensing to determine the sensing and regulation mechanisms of temperature adaptation. The transient receptor potential (TRP is one of the key components of an organism's temperature perception system. TRP plays important roles in perceiving temperature, such as avoiding high temperature, low temperature and choosing the optimum temperature. To assess high temperature sensation and the heat resistance role of the TRP gene, we used 3' and 5' rapid-amplification of cDNA ends to isolate the full-length cDNA sequence of the TRP gene from Bemisia tabaci (Gennadius MEAM1 (Middle East Asia Minor 1, examined the mRNA expression profile under various temperature conditions, and identified the heat tolerance function. This is the first study to characterize the TRP gene of invasive B. tabaci MEAM1 (MEAM1 BtTRP. The full-length cDNA of MEAM1 BtTRP was 3871 bp, and the open reading frames of BtTRP was 3501 bp, encoding 1166 amino acids. Additionally, the BtTRP mRNA expression level was significantly increased at 35°C. Furthermore, compared with control treatments, the survival rate of B. tabaci MEAM1 adults was significantly decreased under high temperature stress conditions after feeding with dsRNA BtTRP. Collectively, these results showed that MEAM1 BtTRP is a key element in sensing high temperature and plays an essential role in B. tabaci MEAM1 heat tolerance ability. Our data improved our understanding of the mechanism of temperature sensation in B. tabaci MEAM1 at the molecular level and could contribute to the understanding of the thermal biology of B. tabaci MEAM1 within the context of global

  7. Within-plant distribution and sampling of single and mixed infestations of Bemisia tabaci and Trialeurodes vaporariorum (Homoptera: Aleyrodidae) in winter tomato crops.

    Science.gov (United States)

    Arnó, Judit; Albajes, Ramon; Gabarra, Rosa

    2006-04-01

    In several areas of Spain, the greenhouse whitefly, Trialeurodes vaporariorum (Westwood), and the sweet potato whitefly, Bemisia tabaci (Gennadius), coexist in tomato, Lycopersicon esculentum Miller. For integrated pest management decision-making, it is important to know the abundance of each species, because they exhibit different abilities to transmit viruses, are susceptible to different biological control agents, and have different responses to insecticides. This study was conducted to provide information on the vertical distribution of T. vaporariorumn and B. tabaci in tomato plants grown in greenhouses in winter and to determine the optimal sampling unit and the sample size for estimating egg and nymphal densities of both whitefly species. Eggs of T. vaporariorum were mainly located on the top stratum of the plant, whereas B. tabaci eggs were mainly found on the middle stratum. Nymphs of both species mainly concentrated in the bottom stratum of the plant. When pest abundance and low relative variation were considered, the bottom stratum was selected as the most convenient for sampling nymphs of both whitefly species. Conversely, the same two criteria indicated that either the top or the middle strata could be used when sampling T. vaporariorum and B. tabaci eggs. Several different sampling units were compared to optimize the estimation of nymphal and egg densities in terms of cost efficiency. One disk (1.15 cm in diameter) per leaflet collected from the top stratum of the tomato plant was the most efficient sampling unit for simultaneously estimating the egg densities of the two whitefly species.

  8. 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 ...

  9. The Bemisia tabaci species complex: Additions from different parts of the world

    NARCIS (Netherlands)

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

    2013-01-01

    Bemisia tabaci is one of the most threatening pests in many crops. We sequenced part of the mitochondrial cytochrome oxidase I gene from fifty whitefly populations collected in Indonesia, Thailand, India and China. Nineteen unique sequences (haplotypes) of the cytochrome oxidase I were identified in

  10. Insecticidal activities of azadirachtin and its effects on sweetpotato whitefly,Bemisia tabaci%印楝素的杀虫活性及其对烟粉虱的驱避作用

    Institute of Scientific and Technical Information of China (English)

    文吉辉; 侯茂林; 卢伟; 黎家文

    2007-01-01

    印楝素(azadirachtin)被认为是最有发展前景的植物源杀虫剂.文章主要介绍印楝素对昆虫的接触驱避、产卵驱避、拒食、毒杀、降低生殖力、生长调节等作用及其作用机理.同时也论述印楝素对烟粉虱Bemisia tabaci(Gennadius)寄主选择、产卵、孵化、若虫发育的影响.

  11. Nuevos registros de especies del género Eretmocerus (Hymenoptera: Aphelinidae, parasitoides de Trialeurodes vaporariorum y el complejo Bemisia tabaci (Hemiptera: Aleyrodidae en Argentina

    Directory of Open Access Journals (Sweden)

    Silvia N. LÓPEZ

    2008-01-01

    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.

  12. 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

  13. 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.

  14. Identification and evaluation of suitable reference genes for gene expression studies in the whitefly Bemisia tabaci (Asia I) by reverse transcription quantitative realtime PCR.

    Science.gov (United States)

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

    2014-05-02

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

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

    Science.gov (United States)

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

    2016-01-01

    Begomovirus ssDNA plant virus (family Geminiviridae) replication within the Bemisia tabaci vector is controversial. Transovarial transmission, alteration to whitefly biology, or detection of viral transcripts in the vector are proposed as indirect evidence of replication of tomato yellow leaf curl virus (TYLCV). Recently, contrasting direct evidence has been reported regarding the capacity of TYLCV to replicate within individuals of B. tabaci based on quantitave PCR approaches. Time-course experiments to quantify complementary and virion sense viral nucleic acid accumulation within B. tabaci using a recently implemented two step qPCR procedure revealed that viral DNA quantities did not increase for time points up to 96 hours after acquisition of the virus. Our findings do not support a recent report claiming TYLCV replication in individuals of B. tabaci. PMID:27476582

  16. Host plant effects on alkaline phosphatase activity in the whiteflies, Bemisia tabaci Biotype B and Trialeurodes vaporariorum.

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

    Hu, Jing S; Gelman, Dale B; Blackburn, Michael B

    2003-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jing S. Hu

    2003-08-01

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

  19. Plastic cup traps equipped with light-emitting diodes for monitoring adult Bemisia tabaci (Homoptera: Aleyrodidae).

    Science.gov (United States)

    Chu, Chang-Chi; Jackson, Charles G; Alexander, Patrick J; Karut, Kamil; Henneberry, Thomas J

    2003-06-01

    Equipping the standard plastic cup trap, also known as the CC trap, with lime-green light-emitting diodes (LED-plastic cup trap) increased its efficacy for catching Bemisia tabaci by 100%. Few Eretmocerus eremicus Rose and Zolnerowich and Encarsia formosa Gahan were caught in LED-plastic cup traps. The LED-plastic cup traps are less expensive than yellow sticky card traps for monitoring adult whiteflies in greenhouse crop production systems and are more compatible with whitefly parasitoids releases for Bemisia nymph control.

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

    Science.gov (United States)

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

    2014-04-01

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

  1. 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.

  2. 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...

  3. 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...

  4. 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...

  5. Acylsucrose-producing tomato plants forces Bemisia tabaci to shift its preferred settling and feeding site.

    Directory of Open Access Journals (Sweden)

    Maria Jose Rodríguez-López

    Full Text Available 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. METHODOLOGY/PRINCIPAL FINDINGS: Whitefly settlement preference was evaluated on the adaxial and abaxial leaf surfaces of nearly-isogenic tomato lines with and without B. tabaci-resistance traits, 'ABL 14-8 and Moneymaker' respectively, under non-choice and free-choice conditions. In addition, the Electrical Penetration Graph technique was used to study probing and feeding activities of B. tabaci on the adaxial and abaxial leaf surfaces of the same genotypes. B. tabaci preferred to settle on the abaxial than on the adaxial surface of 'Moneymaker' leaves, whereas no such preference was observed on ABL 14-8 tomato plants at the ten-leaf growth stage. Furthermore, B. tabaci preferred to feed on the abaxial than on the adaxial leaf surface of 'Moneymarker' susceptible tomato plants as shown by a higher number of sustained phloem feeding ingestion events and a shorter time to reach the phloem. However, B. tabaci standard probing and feeding behavior patterns were altered in ABL 14-8 plants and whiteflies were unable to feed from the phloem and spent more time in non-probing activities when exposed to the abaxial leaf surface. CONCLUSIONS/SIGNIFICANCE: The distorted behavior of B. tabaci on ABL 14-8 protects tomato plants from the transmission of phloem-restricted viruses such as Tomato yellow leaf curl virus (TYLCV, and forces whiteflies to feed on the adaxial side of leaves where they feed less efficiently and become more vulnerable to natural enemies.

  6. 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.

  7. 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

  8. 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.

  9. Development of an antibody-based diagnostic method for the identification of Bemisia tabaci biotype B.

    Science.gov (United States)

    Baek, Ji Hyeong; Lee, Hye Jung; Kim, Young Ho; Lim, Kook Jin; Lee, Si Hyeock; Kim, Bum Joon

    2016-07-01

    The whitefly Bemisia tabaci is a very destructive pest. B. tabaci is composed of various morphologically undistinguishable biotypes, among which biotypes B and Q, in particular, draw attention because of their wide distribution in Korea and differential potentials for insecticide resistance development. To develop a biotype-specific protein marker that can readily distinguishes biotypes B from other biotypes in the field, we established an ELISA protocol based on carboxylesterase 2 (COE2), which is more abundantly expressed in biotypes B compared with Q. Recombinant COE2 was expressed, purified and used for antibody construction. Polyclonal antibodies specific to B. tabaci COE2 [anti-COE2 pAb and deglycosylated anti-COE2 pAb (DG anti-COE2 pAb)] revealed a 3-9-fold higher reactivity to biotype B COE2 than biotype Q COE2 by Western blot and ELISA analyses. DG anti-COE2 pAb exhibited low non-specific activity, demonstrating its compatibility in diagnosing biotypes. Western blot and ELISA analyses determined that one of the 11 field populations examined was biotype B and the others were biotype Q, suggesting the saturation of biotype Q in Korea. DG anti-COE2 pAb discriminates B. tabaci biotypes B and Q with high specificity and accuracy and could be useful for the development of a B. tabaci biotype diagnosis kit for on-site field applications. PMID:27265822

  10. 微卫星位点在Q型烟粉虱入侵种群中的多态性分析%Polymorphisms of microsatellite loci within invasive populations of Bemisia tabaci biotype Q

    Institute of Scientific and Technical Information of China (English)

    刘国霞; 褚栋

    2011-01-01

    During the past several years, the Bemisia tabaci (Gennadius) Q-biotype has invaded China and become the predominant biotype by replacing the previously established B-biotype in some areas. B. tabaci's genetic polymorphism could be influenced by the invasion process and pesticides used. The polymorphism information content (PIC) of 4 microsatellite loci in Q-biotype populations from Shandong Province was assessed and used to determine the genetic diversity of these populations. The results show that all 4 loci were moderately or highly polymorphic indicating that these loci are informative for determining the genetic diversity of invasive Q-biotype populations. These results provide a foundation for determining the utility of microsatellite markers in the invasive Q-biotype.%近年来烟粉虱Bemisia tabaci(Gennadius) Q 型入侵我国并在部分地区取代B型成为了烟粉虱优势生物型.外来物种的入侵过程及农药使用等因素可影响种群的遗传多样性水平及其遗传结构.本研究分析了4个微卫星位点在Q型烟粉虱入侵种群的多态信息含量(PIC),并在此基础上进行了遗传多样性分析.结果表明这些微卫星位点在Q型烟粉虱入侵种群中具有中度或高度多态性,说明微卫星位点能有效分析Q型入侵种群的遗传多态性.本研究为利用微卫星标记研究Q型入侵种群的遗传结构奠定了基础.

  11. 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...

  12. 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

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

    Directory of Open Access Journals (Sweden)

    Francisco das Chagas Vidal Neto

    2008-02-01

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

  15. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 一种快速鉴别烟粉虱与温室白粉虱成虫的方法——复眼镜检法%Rapid differentiation between Bemisia tabaci and Trialeurodes vaporariorum adults by microscopic examination of compound eyes

    Institute of Scientific and Technical Information of China (English)

    褚栋; 王斌; 张四海; 陶云荔; 刘国霞

    2008-01-01

    介绍能够快速鉴别2种形态相似的重要农业害虫即烟粉虱Bemisia tabaci(Gennadius)和温室白粉虱Trialeurodes vaporariorum(Westwood)成虫的方法--复眼镜检法及其应用.复眼镜检法研究表明,烟粉虱成虫上部复眼、下部复眼之间有一个小眼连接,而温室白粉虱成虫上部复眼、下部复眼是完全分离的.

  18. The first record of a cryptic Bemisia tabaci MED species in Guangdong%广东首次发现Q型烟粉虱种群分布

    Institute of Scientific and Technical Information of China (English)

    孙秀新; 薛夏; 任素丽; 任顺祥; 邱宝利

    2013-01-01

    The whitefly Bemisia tabaci (Gennadius) is a globally distributed, phloem-feeding insect that transmits more than 110 plant viruses. Since its first record in China on Poinsettia in Kunming in 2003, the B. tabaci Q biotype (belonging to a Mediterranean cryptic species) has been found to have spread to more than 10 provinces, gradually replacing the B biotype ( MEAM1 cryptic species). However, the B. tabaci Q biotype had not been reported in Guangdong, a Province with a large volume of internal and international trade. However, a population of the Q biotype was recently identified from specimens collected from a hibiscus plant in Changban Park, Guangzhou City. PCR and DNA sequencing using B/Q biotype primers revealed that this population is 1-2 base pairs different from known Q biotype populations in Yunnan, Jiangsu and Zhejiang provinces. Neighbour-joining phylogenetic tree analysis indicates that this Guangzhou Q biotype is closer to the Q biotype populations in Yunnan and Jiangsu provinces, and that it is probably of western Mediterranean, Greece, Spain, Morocco etc. The B. tabaci Q biotype is considered to have higher resistance to chemicals and a greater ability to transmit plant viruses. The first record of this pest in Guangzhou could indicate that this pest is already well established in this Province. Further investigation is required to monitor its spread, host plants and damage.%烟粉虱Bemisia tabaci (Gennadius)是全世界分布的刺吸式传毒昆虫,其中Q型烟粉虱自2003年首次在昆明一品红上发现以来,该种群已在全国10多个省份广泛传播,并有逐步取代B型烟粉虱的趋势.然而,作为较早对外开放的沿海省份,广东省一直未有Q型烟粉虱在田间分布危害的报道.本文利用常规PCR、特异B/Q型烟粉虱引物扩增及DNA测序技术,对近期在广州长湴公园扶桑寄主上采集的烟粉虱种群进行了分子鉴定,并对该种群与国内外其它Q型种群的系统发育关系进行

  19. The Population Dynamics of Bemisia tabaci and Trialeurodes vaporariorum in Shandong Province and Their Distribution%山东省烟粉虱与温室白粉虱种群动态及其地理分布调查

    Institute of Scientific and Technical Information of China (English)

    褚栋; 周洪旭; 王斌; 陶云荔; 刘国霞; 朱国仁; 张友军

    2007-01-01

    烟粉虱(Bemisia tabaci Gennadius)和温室白粉虱(Trialeurodes vaporariorum Westwood)是山东省农作物上主要的粉虱物种.2006年6月至8月调查表明,这两种粉虱具有相似的空间生态位,不同植物上种群数量存在差异.2006年9月中下旬调查结果表明,山东各地农作物上烟粉虱仍是粉虱优势种群.本文还探讨了烟粉虱与温室白粉虱的种群动态关系及其影响因素.

  20. MtDNA variability in whitefly (Bemisia tabaci) populations in Brazil.

    Science.gov (United States)

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

    2011-01-01

    Bemisia tabaci (Hemiptera: Aleyrodidae) consists of a complex of morphologically indistinct biotypes that vary mainly in their capacity to transmit plant viruses and to induce physiological disorders in plants of economic importance. The adaptability of B. tabaci to many regions of the world has fostered the appearance of various biotypes and has resulted in a broad spectrum of host plants. Our goal was to identify which biotypes were present in four B. tabaci populations in Brazil. We quantified genetic variability between and within populations. Three individuals were collected from three host plant species: two populations on soybean (Campinas and Rondonópolis), one on pumpkin (Barreiras) and one on tomato (Cruz das Almas) in three States of Brazil (São Paulo, Mato Grosso, and Bahia). We chose one sequence of the B biotype, obtained from GenBank; the Campinas population, which had been previously characterized as biotype B, was used as a control for this biotype. We also included one sequence of the Q biotype, obtained from GenBank, as an outgroup. The COI region of the mtDNA gene was partially amplified with the CI-J-2195 and L2-N-3014 pair of primers, and the reaction products were sequenced. Based on distance-based algorithm analyses, we found that all haplotypes belong to biotype B, which was confirmed by the haplotype network. Genetic structure analyses showed that the host plant species does not influence population structuring of this pest; only the geographic location mattered. PMID:21968683

  1. 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

  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. 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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    Lucas Castro Torres

    2012-01-01

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

  5. Resistance of soybean genotypes to Bemisia tabaci (Genn.) Biotype B (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Vieira, S S; Bueno, A F; Boff, M I C; Bueno, R C O F; Hoffman-Campo, C B

    2011-01-01

    The silverleaf whitefly Bemisia tabaci (Genn.) biotype B has become a serious problem for soybean cultivation because it can significantly reduce soybean productivity. The use of soybean cultivars resistant to whitefly attack is an important strategy in an integrated pest management (IPM) program. This study evaluated the preference for oviposition and colonization by B. tabaci biotype B on different soybean genotypes. In the free-choice test, the genotypes studied were 'IAC 17' and 'IAC 19' as the standards for resistance and 'IAC Holambra Stwart' as the standard for susceptibility, as well as BABR01-0492, BABR01-0173, BABR01-1259, BABR01-1576, BABR99-4021HC, BABR99-4021HP, 'Barreiras', 'Conquista', 'Corisco', 'BRS Gralha', PI274454, PI227687, and PI171451. In the no-choice test, the four best genotypes selected in the free-choice test, in addition to the susceptible and resistant standards were evaluated. Our data indicated 'Barreiras' as the most resistant genotype against B. tabaci biotype B. 'BRS Gralha', which was the least attractive to whitefly adults in the free-choice test, did not show resistance to insect attack when they were confined in cages in the no-choice test. Despite the high number of eggs observed, BABR01-1576 and BABR99-4021HC showed a reduced number of nymphs, indicating antibiosis. The genotypes with a high level of resistance can be used as a tool against B. tabaci in IPM or as a source of resistance in plant-breeding programs.

  6. 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.

  7. Identification of the molting hormone of the sweet potato (Bemisia tabaci) and greenhouse (Trialeurodes vaporariorum) whitefly.

    Science.gov (United States)

    Gelman, Dale B; Blackburn, Michael B; Hu, Jing S

    2005-01-01

    In order to identify the whitefly molting hormone, whole body extracts of mature 4th instar and newly formed pharate adult Bemisia tabaci (Biotype B) and Trialeurodes vaporariorum were prepared and subjected to reverse phase high performance liquid chromatography (RPHPLC). Ecdysteroid content of fractions was determined by enzymeimmunoassay (EIA). The only detectable ecdysteroids that were present in significant amounts in whitefly extracts were ecdysone and 20-hydroxyecdysone. The concentrations of 20-hydroxyecdysone in B. tabaci and T. vaporariorum extracts, respectively, were 40 and 15 times greater than the concentrations of ecdysone. The identity of the two ecdysteroids was confirmed by normal phase high performance liquid chromatography (NPHPLC). When ecdysteroid content of RPHPLC fractions was assayed by radioimmunoassay (RIA), small amounts of polar ecdysteroids were also detected indicating that these ecdysteroids have a very low affinity for the antiserum used in the EIA. Ecdysteroid at 10.4 mM administered by feeding stimulated 2nd instar whitefly nymphs to molt. Based on our results, it appears that 20-hydroxyecdysone is the whitefly molting hormone.

  8. 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.

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

    Institute of Scientific and Technical Information of China (English)

    Alejandro F Lucatti; Sjaak van Heusden; Colette Broekgaarden; Roland Mumm; Marcel Dicke; Ben Vosman

    2016-01-01

    The whitefly Bemisia tabaci is a serious threat in tomato cultivation worldwide as all varieties grown today are highly susceptible to this devastating herbivorous insect. Many accessions of the tomato wild relative Solanum pennellii show a high resistance towards B. tabaci. A mapping approach was 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 F2BC1 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 suscepti-bility, 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 correla-tion between biochemical-based resistance characteristics and reduced whitefly incidence in S. pennellii.

  10. 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

  11. 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...

  12. 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...

  13. [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.

  14. 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.

  15. 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)

  16. 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.

  17. Identification of three major Bemisia tabaci biotypes in China based on morphological and DNA polymorphisms

    Institute of Scientific and Technical Information of China (English)

    Baoli Qiu; Yanping Chen; Li Liu; Weilu Peng; Xiaoxi Li; Yuzhou Du; Shunxiang Ren

    2009-01-01

    The sweet potato whitefly, Bemisia tabaci, is a complex species, and many of its biotypes are important agricultural pests. The B and Q biotypes are invasive and coexist with the native Cv biotype on vegetable and ornamental crops in China. In this study, these three bio-types were identified based on their morphological characteristics, RAPD-PCR analysis, and DNA sequences of the COl gene. The ante-rior and posterior wax fringes of the B, Q, and Cv biotypes significantly differed from each other. Based on this morphological characteristic, the three biotypes can easily be distinguished in greenhouses and fields. Genomic DNA RAPD-PCR band patterns also revealed differences between these biotypes using the H16 primer. The B biotype has three bright DNA bands between 250 and 600 bp, the Q biotype only has one bright band at ~300 bp, while the Cv biotype has no band between 250 and 500 bp. Both the Cv and Q biotypes have two bright bands at ~750 and 1000 bp while the B biotype has only one band at ~1000 bp. Based on the COI gene, the genetic identity between B and Cv, B and Q, and Q and CV was 85.8%, 94.7%, and 86.0%, respectively. The MP tree indicated that the phylogenetic relationship between the B and Q biotypes is much closer than that between the B and Cv or the Q and Cv biotypes. The uses of the morphological, RAPD-PCR, and DNA sequencing methods in biotype identification of B. tabaci are discussed.

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

    KAUST Repository

    Ragab, Alaa I.

    2013-05-01

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

  19. 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

  20. Molecular cloning and bioinformatics analysis of theBemisia tabaci Mediterranean (MED) transient receptor potential (TRP) gene%烟粉虱MED隐种TRP基因全长cDNA克隆及生物信息学分析

    Institute of Scientific and Technical Information of China (English)

    李倩; 吕志创; 李子玲; 万方浩

    2015-01-01

    [Objectives] Recently, researchers have paid more attention to the insect temperature sensing mechanism of which the transient receptor potential (TRP) is one of key components. Studying the temperature sensing mechanism will provide a theoretical basis for understanding the regulatory mechanism involved in temperature adaptation. TRP plays important roles in perceiving temperature, such as avoiding extreme temperatures and choosing the optimum temperature. [Methods] In the present study, we used 3′RACE and 5′RACE to isolate the TRP gene cDNA sequence fromtheBemisia tabaci(Gennadius) Mediterranean (MED) cryptic species, and bioinformatics to characterize the TRP genes molecular structure and analyze its phylogenetic relationships. [Results] The TRP gene ofB. Tabaci MED, namedBtTRP, had an open reading frame of 3 501 bp, encoding 1 166 amino acids. The encoded products included 6 transmembrane structures, which are one of the features of transient receptor ion channels.Bemisia tabaciMEDBtTRP displayed 75% and 71% similarity with that ofAcyrthosiphon pisum(Harris) andBombus terrestris(Linnaeus), respectively.[Conclusion] These results provide basic information for further study of theBtTRP gene function underlyingB. tabaciMED temperature perception, and provide a theoretical basis for understanding the temperature perception of insects and their adaptability.%[目的]近几年,昆虫温度适应的感知机理备受研究者的关注.由瞬时感受器离子通道(Transient receptor potential,TRP)介导的温度感知系统是影响昆虫温度感知的关键组成.研究温度感知机制关键调控因子的功能可为明确温度感知以及温度适应调控机理提供理论依据.TRP具有感知高温、低温以及在适温范围内温度选择等功能,对昆虫感知温度有重要的作用.[方法]本研究以烟粉虱Bemisia tabaci (Gennadius)Mediterranean(MED)隐种为研究对象,采用反转录PCR(Reverse transcription PCR,RT-PCR)

  1. THE PEST STATUS OF BEMISIA TABACI IN CHINA AND NON-CHEMICAL CONTROL STRATEGIES%烟粉虱在我国的发生为害现状及其非化学控制对策

    Institute of Scientific and Technical Information of China (English)

    任顺祥; 王振中; 秋宝利; 肖燕

    2001-01-01

    烟粉虱(Bemisiatabaci Gennadius)是热带、亚热带和温带地区主要害虫之一。烟粉虱早在40年代在我国就已有记载,现广泛分布于我国的22个省市。过去烟粉虱在我国为害并不严重,近年来在广东和北京等地已成为蔬菜和园艺作物生产的严重障碍。除直接为害外,烟粉虱可传播番茄和南瓜曲叶病等5种难于防治的病毒病。到目前为止,已报到18种寄生性天敌、17种捕食性天敌及1种虫生真菌。本文简要慨述烟粉虱在我国的发生为害与传毒现状,并结合我国的具体情况提出非化学控制烟粉虱的对策。%Bemisia tabaci (Gennadius) has been considered as a serious post in all of tropical, subtropical and temperate regions of the world. B. tabaci first recorded as early as in 1940s in China and has been reported as a pest of various crops in 22 provinces or cities. But only recently it has become a severe problem for vegetable and orna mental crops in Guangdong and Beijing. In China B. tabaci is known to transmit at least 5 plant viruses, including tomato yellow leaf curl virus (TYLCV), tomato leaf curl virus (TomLCV), squash leaf curl virus (SqLCV-C). So far, approximately 18 parasitoids, 17 predators and 1 pathogenic fimgus were recorded in China. This paper presents an overview of B. tabaci as a pest and virus vector in China, with spocial attention given to non-chemical control strategies.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Wen eXie

    2014-12-01

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

  4. 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.

  5. 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...

  6. 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 ...

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

    Science.gov (United States)

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

    2014-01-01

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

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    Roee eShavit

    2013-08-01

    Full Text Available 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 rizhobacteria (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 investigated the effect of tomato (Solanum lycopersicum pre-inoculation with the PGPR Pseudomonas fluorescens WCS417r, on the performance of the generalist phloem-feeding insect Bemisia tabaci. Based on the ability of P. fluorescens WCS417r to prime for ISR against generalists chewing insects and necrotrophic pathogens, we hypothesized that pre-inoculated plants will strongly resist B. tabaci infestation. In contrast, we discovered that the pre-inoculation treatment increased the tomato plant suitability for B. tabaci which was emphasized both by faster developmental rate and higher survivability of nymph stages on pre-inoculated plants. Our molecular and chemical analyses suggested that the phenomenon is likely to be related to: (I the ability of the bacteria to reduce the activity of the plant induced defense systems; (II a possible manipulation by P. fluorescens of the plant quality (in terms of suitability for B. tabaci through an indirect effect on the rhizosphere bacterial community. The contribution of our study to the pattern proposed for other belowground rhizobacteria and mycorrhizal fungi and aboveground generalist phloem-feeders is discussed.

  10. 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

  11. 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 ...

  12. 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.

  13. Monitoring of biotypes and occurrence of Bemisia tabaci in Jiangsu Province, China%江苏地区烟粉虱发生危害及其生物型监测

    Institute of Scientific and Technical Information of China (English)

    蔡力; 许丽丽; 杜以梅; 杜予州

    2015-01-01

    [Objectives] Biotypes Q and B are two of the most prevalent cryptic species of Bemisia tabaci (Gennadius) (Hemiptera: Aleypdidae) and have consequently been the focus of considerable research as this pest has spread rapidly around the world. In an extensive field survey of the B. tabaci complex throughout Jiangsu Province from 2010 to 2013, we investigated the occurrence and distribution of these two whiteflies in Jiangsu Province. [Methods] Microscopic examination was used to detect crop damage caused by B.tabaci, and a rapid test for identifying biotypes was conducted based on the mtCOⅠgene. [Results] Crop damage first increased in 2011 then decreased in 2013. Similarly, damage also first increased then declined in South and North Jiangsu, but in the Central Jiangsu the opposite trend was apparent. Moreover, damage to eggplant, cucumber and pumpkin crops was relatively high. [Conclusion] The results show that the abundance of B. tabaci differs from year to year in different regions and on different hosts. The resultant differences in crop damage have no direct relationship to the population dynamics of the two whitefly biotypes. Although biotype Q has replaced biotype B as the dominant biotype in Jiangsu Province, we still could detect a small, but gradually increasing, proportion of biotype B in southern and northern Jiangsu.%【目的】随着 Q 型和 B 型烟粉虱 Bemisia tabaci (Gennadius)在全世界范围内的传播和入侵,两种入侵烟粉虱的发生危害和种群扩张越来越受到人们的关注。本文对2010—2013年江苏省内烟粉虱的发生危害程度及其生物型的分布进行了全面的调查研究。【方法】应用室内镜检鉴定烟粉虱的发生危害程度,同时结合 mtCOⅠ分子标记快速检测法鉴定烟粉虱的生物型。【结果】从时间来看,烟粉虱的发生危害程度在2011年最严重,而在2013年最低,呈“先上升后下降”的趋势。从不同地区来

  14. 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

  15. 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

  16. 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.

  17. 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

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

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    María del Rosario Manzano Martínez

    2009-10-01

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

  19. 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.

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

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    A. Helmi

    2011-01-01

    Full Text Available 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 (RAPD markers. Fifteen RAPD primers were screened seven of them were produced 218 DNA fragments, 209 of them were polymorphic while the other nine bands could be considered as common for B. tabaci. Total number of bands obtained from each primer ranged from 23-44 with an average of 36.33 bands per primer. RAPD-PCR analysis led to identification of 42 polymorphic markers holding specificity for these hosts' populations. Phylogenetic relationships among the studied populations using this technique clearly separated these six populations into two main clusters with similarity matrix percentage of 88 and 64%. These results indicated that B. tabaci may have different genotypes on adaptations to certain host plant species in Egypt.

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

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    Yi-Wei Fang

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

  2. EPG-recorded probing and feeding behaviors of Bemisia tabaci and Trialeurodes vaporariorum on cabbage%烟粉虱和温室粉虱在甘蓝上的刺探取食行为比较

    Institute of Scientific and Technical Information of China (English)

    高庆刚; 罗晨; 郭晓军; 墨铁路; 张芝利

    2006-01-01

    利用刺吸电波图技术研究B型、ZHJ-1型烟粉虱Bemisia tabaci(Gennadius)和温室粉虱Trialeurodes vaporariorum(Westwood)在甘蓝上的取食行为,将3种粉虱的电波图进行比较,其中,B型和ZHJ-1型烟粉虱记录到np,C,pd,E1,E2,F和G波7种波形,温室粉虱只记录到刺探波形,少有取食波形.B型的20个记录中只有1个没有持续吸食波形;ZHJ-1型的25个记录中有10个记录没有持续吸食波形;温室粉虱没有持续吸食记录.甘蓝叶片韧皮部的结构或汁液的化学成分与温室粉虱的抗性密切相关.

  3. Further compatibility tests of the entomopathogenic fungus Lecanicillium muscarium with conventional insecticide products for control of sweetpotato whitefly, Bemisia tabaci on poinsettia plants

    Institute of Scientific and Technical Information of China (English)

    Andrew G. S. Cuthbertson; Lisa F. Blackburn; Phil Northing; Weiqi Luo; Raymond J. C. Cannon; Keith F. A. Waiters

    2008-01-01

    The effect on spore germination of the entomopathogenic fungus Lecanicillium muscarium following direct exposure for 24 h to the insecticides Majestik, Spray Oil, Agri50E, Savona and Oberon for the control of both egg and second instar stages of the sweetpotato whitefly, Bemisia tabaci, was determined. Exposure to both Agri-50E and Oberon was followed by acceptable spore germination. Infectivity rates of L. rnuscarium on poinsettia foliage in the presence of dry residues of the insecticides were also investigated.No significant detrimental effects on the levels of control of B. tabaci were recorded compared with fungus applied to residue-free foliage. Sequential application of the chemicals Savona, Spray Oil and Majestik with the fungus all produced mortalities of second instar B. tabaci above 90%. Incorporation of these chemicals with L. muscarium into integrated control programs for B. tabaci is discussed.

  4. 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.

  5. Assessment of potential sublethal effects of various insecticides on key biological traits of the tobacco whitefly, Bemisia tabaci.

    Science.gov (United States)

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

    2013-01-01

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

  6. 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.

  7. USING RAPD-PCR TO DISTINGUISH BIOTYPES OF BEMISIA TABACI ( HOMOPTERA: ALEYRODIDAE) IN CHINA%RAPD方法用于区分中国烟粉虱的生物型

    Institute of Scientific and Technical Information of China (English)

    吴杏霞; 胡敦孝; 李正西; 沈佐锐

    2002-01-01

    应用RAPD-PCR技术研究了中国大陆10个烟粉虱种群的生物型情况.聚类分析表明:这10个种群中包含了3种生物型:烟粉虱B型、广西型(南宁南瓜寄主)和福建型(福州地瓜).值得注意的是,在福建并存着两种烟粉虱生物型,即甘蓝上的B型烟粉虱和甘薯上的福建福州型.研究表明烟粉虱B型已经传入中国,至少在北京、山东、新疆、福建、广东等地都有发生和分布.广西型和福建型是否中国的本土种群还需进一步研究.%Ten populations of the whitefly Bemisia tabaci (Gennadius) collected from eight fieed and ornamentalcrops from seven provinces/cities in China were determined using RAPD-PCR. Results showed that the 10 populations ofB. tabaci could be classified into three distinct groups: a Biotype B group, a Guangxi group, and a Fujian group. Thewhiteflies in the Biotype B group were collected from sweetpotato and cotton in Beijing, tomato in Shandong, poinsettiain Shanghai and Guangdong, cabbage in Fujian, and hemp and eggplant in Xinjiang. The Guangxi group were collectedfrom pumpkin in Nanning, Guangxi, and the Fujian group, from sweetpotato in Fujian. It was notable that B. tabacispecimens collected on cabbage in Fujian belonged to the Biotype B group. It is clear that Biotype B does now occur inChina, in Beijing, Shandong, Xinjiang, Shanghai, Fujian and Guangdong. It is likely that the Guangxi and Fujiangroups are native to China.

  8. 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

  9. 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

  10. 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)

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

    Directory of Open Access Journals (Sweden)

    Giuliana Etore do Valle

    2002-06-01

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

  12. 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...

  13. Preliminary study of succession of Bemisia tabaci biotypes in Jiangsu Province, China%江苏地区烟粉虱生物型演替研究初报

    Institute of Scientific and Technical Information of China (English)

    沈媛; 杜予州; 任顺祥; 邱宝利

    2011-01-01

    本文连续5年系统监测了江苏省13个地级市烟粉虱Bemisia tabaci(Gennadius)生物型的发生分布状况,探讨了它们的迁移扩散和演替规律.利用RAPD分子标记和mtDNA COI基因序列进行烟粉虱生物型鉴定,结果表明:江苏地区发生的烟粉虱生物型为B型和Q型.自2005年到2009年,B型烟粉虱在苏南和苏北地区的发生分布频率逐年下降,在苏北地区的发生分布频率由52.58%下降为22.22%,在苏南由56.52%下降为9.37%;而Q型烟粉虱在苏南和苏北的发生分布频率逐年升高,在苏北由47.42%上升至77.78%,在苏南由43.48%上升为90.63%.B型烟粉虱的发生分布范围由全省逐渐向苏北地区缩小,而Q型烟粉虱的发生分布范围逐渐扩大遍及全省;此外,Q型烟粉虱在江苏是由苏中和苏南地区向苏北地区扩散,并逐步取代B型烟粉虱成为江苏地区农作物的主要害虫.%The occurrence and distribution of Bemisia tabaci(Gennadius) biotypes in 13 cities in Jiangsu Province was surveyed systematically from 2005 to 2009 and biotypes identified on the basis of RAPD marks and mtDNA COI gene sequence. The results showed that the B. tabaci B and Q biotypes co-exist in Jiangsu Province but that the distribution of the B biotype has decreased while that of the Q biotype has increased. The frequency of the B biotype ranged from 52.58% to 22. 22% in Northern Jiangsu and from 56. 52% to 9. 37% in Southern Jiangsu. The distribution of the Q biotype ranged from 47.42% to 77.78% in Northern Jiangsu and from 43.48% to 90. 63% in Southern Jiangsu. The Q biotype has spread from Southern and Central Jiangsu to Northern Jiangsu and has gradually replaced the B biotype as a major crop pest in Jiangsu Province.

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

    Directory of Open Access Journals (Sweden)

    Rosemarije Buitenhuis

    2016-09-01

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

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

    Science.gov (United States)

    Buitenhuis, Rosemarije; Brownbridge, Michael; Brommit, Angela; Saito, Taro; Murphy, Graeme

    2016-01-01

    (1) Global movement of propagative plant material is a major pathway for introduction of Bemisia tabaci (Hemiptera: Aleyrodidae) into poinsettia greenhouses. Starting a poinsettia crop with high pest numbers disrupts otherwise successful biological control programs and widespread resistance of B. tabaci against pesticides is limiting growers' options to control this pest; (2) This study investigated the use of several biopesticides (mineral oil, insecticidal soap, Beauveria bassiana, Isaria fumosorosea, Steinernema feltiae) and combinations of these products as immersion treatments (cutting dips) to control B. tabaci on poinsettia cuttings. In addition, phytotoxicity risks of these treatments on poinsettia cuttings, and effects of treatment residues on mortality of commercial whitefly parasitoids (Eretmocerus eremicus and Encarsia formosa) were determined; (3) Mineral oil (0.1% v/v) and insecticidal soap (0.5%) + B. bassiana (1.25 g/L) were the most effective treatments; only 31% and 29%, respectively, of the treated B. tabaci survived on infested poinsettia cuttings and B. tabaci populations were lowest in these treatments after eight weeks. Phytotoxicity risks of these treatments were acceptable, and dip residues had little effect on survival of either parasitoid, and are considered highly compatible; (4) Use of poinsettia cutting dips will allow growers to knock-down B. tabaci populations to a point where they can be managed successfully thereafter with existing biocontrol strategies. PMID:27681741

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

    Science.gov (United States)

    Buitenhuis, Rosemarije; Brownbridge, Michael; Brommit, Angela; Saito, Taro; Murphy, Graeme

    2016-09-26

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

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

    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

    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] Hamiltonella defensa and Rickettsia infection in B. tabaci varied with host plant, including cotton, tomato, cucumber and sweet potato. Hamiltonella was the most common symbiont on all host plants, and frequency of infection of this symbiont was highest on cotton, followed, in descending order, by cucumber, tomato, and sweet potato. The frequency of Wolbachia and Cardinium infection was not affected by host plant. Females comprised > 60% of all four B. tabaci populations and there was no significant difference in the proportion of females among different host plants. Regression analysis indicates that both Hamiltonella and Rickettsia infection are related to a female biased sex ratio, and quadratic polynomial regression models established an association between infection frequency and female ratio. When the infection rates of Hamiltonella and Rickettsia were lower than 69%and 5%, respectively, the proportion of females increased with infection rate. However, when symbiont infection rates were higher than those above, female ratios decreased with infection rates. [Conclusion] B. tabaci populations on cotton, tomato, cucumber and sweet potato are all female-biased, and sex ratios are not significantly different among different host plants. The infection frequencies of facultative symbionts is related to the population sex ratio.%【目的】烟粉虱 Bemisia tabaci (Gennadius)体内次生共生菌感染受寄

  1. Tomato pathogenesis-related protein genes are expressed in response to Trialeurodes vaporariorum and Bemisia tabaci biotype B feeding.

    Science.gov (United States)

    Puthoff, David P; Holzer, Frances M; Perring, Thomas M; Walling, Linda L

    2010-11-01

    The temporal and spatial expression of tomato wound- and defense-response genes to Bemisia tabaci biotype B (the silverleaf whitefly) and Trialeurodes vaporariorum (the greenhouse whitefly) feeding were characterized. Both species of whiteflies evoked similar changes in tomato gene expression. The levels of RNAs for the methyl jasmonic acid (MeJA)- or ethylene-regulated genes that encode the basic β-1,3-glucanase (GluB), basic chitinase (Chi9), and Pathogenesis-related protein-1 (PR-1) were monitored. GluB and Chi9 RNAs were abundant in infested leaves from the time nymphs initiated feeding (day 5). In addition, GluB RNAs accumulated in apical non-infested leaves. PR-1 RNAs also accumulated after whitefly feeding. In contrast, the ethylene- and salicylic acid (SA)-regulated Chi3 and PR-4 genes had RNAs that accumulated at low levels and GluAC RNAs that were undetectable in whitefly-infested tomato leaves. The changes in Phenylalanine ammonia lyase5 (PAL5) were variable; in some, but not all infestations, PAL5 RNAs increased in response to whitefly feeding. PAL5 RNA levels increased in response to MeJA, ethylene, and abscisic acid, and declined in response to SA. Transcripts from the wound-response genes, leucine aminopeptidase (LapA1) and proteinase inhibitor 2 (pin2), were not detected following whitefly feeding. Furthermore, whitefly infestation of transgenic LapA1:GUS tomato plants showed that whitefly feeding did not activate the LapA1 promoter, although crushing of the leaf lamina increased GUS activity up to 40 fold. These studies indicate that tomato plants perceive B. tabaci and T. vaporariorum in a manner similar to baterical pathogens and distinct from tissue-damaging insects.

  2. 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

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

    Directory of Open Access Journals (Sweden)

    Mohammad Amin Samih

    2014-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Jair Campos Moraes

    2009-10-01

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

  5. 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)

  6. 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...

  7. 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

  8. Effects of host, temperature and relative humidity on competitive displacement of two invasive Bemisia tabaci biotypes [Q and B

    Institute of Scientific and Technical Information of China (English)

    Dong Chu; Yun-Li Tao; You-Jun Zhang; Fang-Hao Wan; Judith K Brown

    2012-01-01

    Bemisia tabaci shifted unexpectedly in China from a predominance of B biotype to Q biotype during 2005-2008.This observation stimulated an interest in investigating whether environmental factors,including host,temperature and relative humidity (RH) could possibly explain the observed shift in biotypes distribution.Results indicated that all three parameters examined influenced biotype survivability.The percentage of B biotype,when reared together on pepper plants with the Q biotype,decreased significantly from 66.7% in the founder population,to 13.6% and 3.7% in the first and second generations,respectively.When the B (founder at 66.7%) and Q (founder at 33.3%) biotypes were reared together on eggplant alone,or on pepper-plus-eggplant combination,the population size of the B biotype either remained constant,or increased somewhat in the first and second generations.On eggplant,the effects of RH and temperature on the competitiveness between the Q and B biotypes (3 pairs of Q and 6 pairs of B) were not significant.

  9. 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)

  10. 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.

  11. 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

    Directory of Open Access Journals (Sweden)

    Aliza Hariton Shalev

    2016-07-01

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

  12. 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

  13. 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

  14. The identification of biotypes of Bemisia tabaci in Hubei Province%湖北省烟粉虱生物型鉴定

    Institute of Scientific and Technical Information of China (English)

    陈冲; 马娟; 王欣茹; 覃春华; 李建洪

    2011-01-01

    Mitochondrial cytochrome oxidase Ⅰ (mtDNA COl) gene sequences were utilized to identify biotypes of Bemisa tabaci ( Gennadius ) in Hubei Province. Of the 720 bp COl sequences examined, those from populations in Dangyang,Xiantao,Tianmen ,Jianli, Yichang and Wuhan had as much as 100% similarity. COl sequences of B. tabaci from these six sites were also 100% similar to those of the Q biotype from the USA and Hubei Province. COl sequences of specimens of a B. tabaci population from Zaoyang were 100% similar to specimens of the B biotype from Israel,Zhejiang and Hubei Province. Ⅰ conclude that B. tabaci from Dang yang, Xiantao, Tianmen, Jianli, Yichang and Wuhan are of the Q biotype where those from Zaoyang are the B biotype.%本研究利用mtDNA COI基因片段作标记,通过序列分析对湖北省烟粉虱Bemisa tabaci(Gennadius)生物型进行了鉴定.结果表明当阳、仙桃、天门、监利、宜昌和武汉6个地理种群烟粉虱的720 bp COI基因序列的同源性高达100%,且该6个地理种群烟粉虱与USA-Q型烟粉虱、湖北Q型烟粉虱的同源性也高达100%.枣阳地区烟粉虱与Israel-B型烟粉虱、我国浙江B型烟粉虱、我国湖北B型烟粉虱的同源性为100%.由此可见当阳、仙桃、天门、监利、宜昌和武汉6个地区烟粉虱生物型属于Q型,仅枣阳地区烟粉虱属于B型.

  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

    Directory of Open Access Journals (Sweden)

    Patricia Valle Pinheiro

    2009-04-01

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

  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

    Directory of Open Access Journals (Sweden)

    Demétrio Martinez Palhares

    2007-09-01

    Full Text Available

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

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

  18. Effect of previous infestation of tomatoes by Bemisia tabaci or Trialeurodes vaporariorum on the fitness of these whitefly species%烟粉虱及温室白粉虱为害后对后续粉虱种群的影响

    Institute of Scientific and Technical Information of China (English)

    陈春丽; 郅军锐; 匡先钜; 戈峰

    2015-01-01

    . vaporariorum was not beneficial to the development of B. tabaci.%【目的】分析烟粉虱 Bemisia tabaci (Gennadius)或温室白粉虱 Trialeurodes vaporariorum (Westwood)为害番茄后对后续温室白粉虱和烟粉虱生长、发育、成虫寿命和繁殖等产生的促进或抑制作用,可为明确寄主植物番茄介导的温室白粉虱-烟粉虱的种间互作,开展粉虱的科学防控提供科学依据。【方法】通过在寄主植物番茄叶片上先将 B 型烟粉虱或温室白粉虱按不同的顺序、时间间隔分开接种,再系统观察后续接上的两种粉虱生长、发育、繁殖等种群参数的变化。【结果】(1)先期接上烟粉虱对后续温室白粉虱的发育、寿命、产卵量有明显的促进作用;这种作用需烟粉虱的持续诱导,若去掉烟粉虱,其对温室白粉虱的促进作用即消失;先期接上温室白粉虱可缩短后续烟粉虱伪蛹期,但温室白粉虱的持续存在不利于烟粉虱的产卵,且明显降低烟粉虱的内禀增长率和净增殖率。(2)先后在番茄上同时接上温室白粉虱可降低后续烟粉虱的单雌产卵量和雌、雄虫的成虫寿命;先后同时接种烟粉虱却显著地增加了温室白粉虱的单雌产卵量;烟粉虱的提前存在降低了后续烟粉虱单雌产卵量。(3)但两种粉虱之间作用存在着一定的时间滞后性。烟粉虱对温室白粉虱的发育、寿命、产卵量产生的促进作用大约在其卵期后的一段时间才能显现出来;温室白粉虱对烟粉虱伪蛹期的缩短作用也需提前诱导;而温室白粉虱对温室白粉虱的促进作用相当滞后,直到成虫期才显现出来。【结论】 B 型烟粉虱和温室白粉虱之间可通过寄主番茄产生相互影响,前期烟粉虱为害可显著促进后续温室白粉虱卵和若虫的发育,而前期温室白粉虱为害对烟粉虱的发育不利。

  19. Critical feeding periods for last instar nymphal and pharate adults of the whiteflies, Trialeurodes vaporariorum and Bemisia tabaci.

    Science.gov (United States)

    Gelman, Dale B; Hu, Jing S

    2007-01-01

    A critical feeding period is the time after which 50% of a given species of insect can be removed from its food source and complete development by undergoing adult eclosion. The critical feeding period was determined for the greenhouse white fly, Trialeurodes vaporariorum, and the sweet potato whitefly, Bemisia tabaci (Biotype B) (Homptera/Hemiptera: Aleyrodidae). Fourth (last) instar and pharate adult whiteflies were removed from green bean leaves, staged, placed on filter paper in small Petri dishes containing drops of water, and observed daily for eclosion. For T. vaporariorum reared at 25 degrees C and L:D 16:8, 55 and 80% adult eclosion were observed when whiteflies were removed at stages 4 (0.23-0.26 mm in body depth) and 5 (> or = 0.27 mm in body depth), respectively, so that at least 50% eclosion was only achieved in this species of whitefly when adult eye development had already been initiated (in Stage 4), and 80% eclosion when adult wing development had been initiated (Stage 5). In contrast, 63% of B. tabaci emerged as adults if removed from the leaf at Stage 3 (0.18-0.22 mm in body depth), and 80% emerged if removed at Stage 4/5, stages in which adult formation had not yet been initiated. The mean number of eggs laid by experimental (those removed at Stages 4-5, 6-7 or 8-9) and control (those that remained on the leaf prior to eclosion) whiteflies, and the mean percent hatch of these eggs were not significantly different in experimental and control groups. Stages 7, 8 and 9 are characterized by a light red adult eye, medium red bipartite adult eye and dark red or red-black bipartite adult eye, respectively. Mean adult longevity also was not significantly different between experimental and control groups. However, for all groups of T. vaporariorum, adult female longevity was significantly (at least 2 times) greater than male longevity. Our results identify the critical feeding periods for last instar/pharate adults of two important pest species of

  20. 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.

  1. 上海地区烟粉虱生物型的最新鉴定%The latest identification of Bemisia tabaci biotype in Shanghai area

    Institute of Scientific and Technical Information of China (English)

    王欢; 李凯

    2015-01-01

    以 mtDNA CO Ⅰ序列标记对上海8个区县的烟粉虱进行了生物型鉴定。序列分析显示,所测33个种群165个样本中,仅发现2种烟粉虱单倍型,即 Q 型与 B 型。B 型仅存于远郊崇明的花椰菜种群与奉贤的南瓜种群,比例为6%;其余各种群均为 Q 型,占94%。结果显示:Q 型烟粉虱已全面取代 B 型烟粉虱,成为上海地区主要优势生物型。%The biotypes of Bemisia tabaci from 8 districts of Shanghai suburbs were identified by mtDNA CO Ⅰ sequence marking.The sequence analysis showed that there were only 2 mtDNA haplotypes(Q and B bio-types)found in the 165 individuals of 33 populations.The B biotype was merely living on both broccoli population in Chongming County and pumpkin population in Fengxian District and accounted for 6%;The Q biotype accoun-ted for 94% and became the major biotype of Bemisia tabaci in Shanghai area.

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

    Directory of Open Access Journals (Sweden)

    Manzano Martínez María del Rosario

    2009-12-01

    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 (rm 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.

  3. Transcriptome analysis of Bemisia tabaci nymphs infected with Beauveria bassiana%感染球孢白僵菌的烟粉虱若虫免疫应答转录组分析

    Institute of Scientific and Technical Information of China (English)

    王登杰; 吴圣勇; 雷仲仁; 王海鸿

    2015-01-01

    Objectives] To screen the whitefly Bemisia tabaci (Gennadius) genes that respond to infection by Beauveria bassiana in order to further elaborate molecular mechanisms underlying the immune response to fungal infection. [Methods] High throughput sequencing technology was used in the transcriptome analysis of Bemisia tabaci 4th instar nymphs that were either infected, or uninfected (control), with B. bassiana. Differentially expressed genes (DEGs) and their functions, classifications and signaling pathways were analyzed using bioinformatic tools. [Results] 232 554 non-redundant Unigenes were identified, among which N50 and N90 were 1 153 bp and 260 bp in length, respectively. The average length of all Unigenes were 674 24 bp. Among the 1 166 DEGs (P<0.05) identified, 474 were up-regulated and 692 were down-regulated, and 405 are known to be involved in insect immune response. The identified Unigenes were enriched in 156 biological processes (66 402 Unigenes), 89 cellular components (27 645 Unigenes) and 154 molecular functions (73 417 Unigenes) by GO analysis. KEGG pathway analysis indicated that 1 145 DEGs were mapped to 309 distinctive pathways, and were enriched in 76 pathways. [Conclusion] Four hundred and five genes that are possibly involved in the immune recognition and defense of whitefly nymphs against B. bassiana infection were sequenced. The results provide a bioinformatic data base for using entomopathogenic fungi as a biological control for whitefly.%【目的】筛选烟粉虱 Bemisia tabaci (Gennadius)若虫应对白僵菌 Beauveria bassiana 侵染的应答基因,以进一步研究烟粉虱免疫反应的分子机制。【方法】采用新一代高通量测序技术对感染和非感染白僵菌的烟粉虱4龄若虫进行了测序分析,并筛选了差异表达基因;利用生物信息学工具对转录组测序得到的基因进行了功能注释、分类以及参与的信号通路展示。【结果】组装得到非冗余 Unigene 232554

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

    Directory of Open Access Journals (Sweden)

    Harpreet Singh Raina

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

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

    Science.gov (United States)

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

    2014-07-01

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

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

    Science.gov (United States)

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

    2014-07-01

    The insecticidal potential of Galanthus nivalis agglutinin-related lectins against hemipterans has been experimentally proven. However, the basis behind the toxicity of these lectins against hemipterans remains elusive. The present study elucidates the molecular basis behind insecticidal efficacy of Colocasia esculenta tuber agglutinin (CEA) against Bemisia tabaci and Lipaphis erysimi. Confocal microscopic analyses highlighted the binding of 25 kDa stable homodimeric lectin to insect midgut. Ligand blots followed by LC MS/MS analyses identified binding partners of CEA as vacuolar ATP synthase and sarcoplasmic endoplasmic reticulum type Ca(2+) ATPase from B. tabaci, and ATP synthase, heat shock protein 70 and clathrin heavy chain assembly protein from L. erysimi. Internalization of CEA into hemolymph was confirmed by Western blotting. Glycoprotein nature of the receptors was identified through glycospecific staining. Deglycosylation assay indicated the interaction of CEA with its receptors to be probably glycan mediated. Surface plasmon resonance analysis revealed the interaction kinetics between ATP synthase of B. tabaci with CEA. Pathway prediction study based on Drosophila homologs suggested the interaction of CEA with insect receptors that probably led to disruption of cellular processes causing growth retardation and loss of fecundity of target insects. Thus, the present findings strengthen our current understanding of the entomotoxic potentiality of CEA, which will facilitate its future biotechnological applications. PMID:24753494

  7. 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.

  8. 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.

  9. Population and host plant differentiation of the sweetpotato whitefly,Bemisia tabaci(Homoptera:Aleyrodidae),in East,South and Southwest China%华东、华南和西南地区烟粉虱的种群及寄主分化

    Institute of Scientific and Technical Information of China (English)

    Muhammad Z.AHMED; 沈媛; 金桂华; 任顺祥; 杜予州; 邱宝利

    2009-01-01

    烟粉虱Bemisia tabaci是一个复合种,它具有的生物型分化、较强的传播病毒的能力和抗药性、较快的繁殖速率等特征使其成为我国农业生产中重要害虫之一.本研究利用细胞色素线粒体氧化酶I基因,对采集自江苏、广东和云南三省的烟粉虱样本进行了生物型鉴定,并对烟粉虱生物型与寄主植物之间的关联性开展了调查.结果表明,在广东和云南省,都存在未鉴定的土著种群与入侵的B型、Q型共存的现象;同时,在本研究中广东省尚未采集到Q型烟粉虱,而在江苏采集到的粉虱样本全部为人侵型.研究结果还表明,相对于入侵种而言,土著种群显示出更强的寄主植物趋同性;丰富的寄主植物以及本身具有的多食性特性有助于B型、Q型等生物型在世界各地的广泛入侵.%The sweetpotato whitefly,Bemisia tabaci(Gennadius),is a species complex that is considered an important agricultural pest because of its diversity in biotypes,capacity to transmit viruses,high resistance to chemicals and rapid physiological development.Its biotype status in Jiangsu,Guangdong and Yunnan provinces was determined by using mitochondrial DNA Col markers and correlated with their host plants and locations.Results indicated that.in Guangdong and Yunnan,the local unresolved biotypes and the already known biotypes 0f B.tabaci(B and O)coexist the fc'rnler is relatively more dependent on its host plants than the invasive biotypes.No Q biotype of B.tabaci has been found in Guangdong and no local biotype has been found in Jiangsu in this studv.Multitudinous host plants and the inherent polyphagous characteristics enhance the wide invasion of B and Q biotypes in different counties.

  10. 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

  11. Comparative on development and reproduction between Bemisia tabaci biotype B and Trialeurodes vaporariorum on four species of host-plants%寄主植物对B型烟粉虱(Bemisia tabaci)和温室粉虱(Trialeurodes vaporariorum)个体发育和种群繁殖的影响

    Institute of Scientific and Technical Information of China (English)

    罗晨; 向玉勇; 郭晓军; 张帆; 张芝利

    2007-01-01

    烟粉虱Bemisia tabaci(Gennadius)和温室粉虱Trialeurodes vaporariorum (Westwood)在我国北方常混合发生,为了解两种粉虱所造成的危害和自身种群的增长变化,制定科学的综合防治措施,在(27±1)℃条件下研究了两种粉虱在棉花Gossypium hirsutum L. (泗棉3号)、黄瓜Cucumis sativas L. (北京202)、茄子Solanum melongena L. (北京七叶茄)和番茄Lycopersicum esculentum Mill. (佳粉十号)上各虫态大小、存活率、发育历期、成虫寿命、平均产卵量等生物学参数.在同一种寄主植物上,温室粉虱的1,2龄若虫的体长和体宽均显著大于烟粉虱,3龄以后两种粉虱的体型则变异较大.两种粉虱从卵到成虫羽化,在棉花上的发育历期无显著差异,在黄瓜、茄子和番茄上,温室粉虱的发育历期(19.7、19.4、20.8d)显著长于烟粉虱(17.3、17.6、18.3d).在黄瓜和番茄上,烟粉虱的平均寿命(31.2、32.1)显著长于温室粉虱的平均寿命(26、24.9d);在棉花、黄瓜和番茄上,烟粉虱的单雌产卵量(122.2、220.2、266.5粒)显著高于温室粉虱(97.1、186.6、197.1粒).烟粉虱在棉花、黄瓜、茄子和番茄上的总存活率分别为67.9%、 77.8%、67.8% 和 59.0% ,温室粉虱依次为 62.2%、67.2%、64.4% 和66.1%.综合比较4种寄主植物,烟粉虱比温室粉虱具有个体发育时间短、种群繁殖速度快、生殖竞争能力强等特点.

  12. 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...

  13. 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.

  14. 上海地区烟粉虱生物型的鉴定%The Identification of Biotypes of Bemisia tabaci in Shanghai Area

    Institute of Scientific and Technical Information of China (English)

    史苹香; 王冬生; 滕海媛; 章巧利; 张天澍; 袁永达; 王建国

    2012-01-01

    烟粉虱是一种由许多生物型组成的复合种,是一种世界性的重要害虫.不同生物型的烟粉虱在寄主范围、传毒能力、抗药性等许多生物学特性方面存在差异.利用mtDNA COI基因作标记对上海地区的烟粉虱生物型进行了分析鉴定.结果表明,所测上海10个代表性地区中,闵行区只检测到B型烟粉虱,嘉定、青浦和徐汇区只检测到Q型烟粉虱,其余各地区B型和Q型两种生物型烟粉虱共存.所测上海地区共45个种群中,有31个种群为Q型,占所测种群的68.9%,14个种群为R型,占31.1%.而且,大棚采集种群多为Q型(Q型占87.0%).结果说明Q型烟粉虱已在上海地区广泛存在、大量发生,并有取代R型烟粉虱成为上海地区烟粉虱主要危害类型的可能.%The Bemisia tabaci (Cennadius) species complex is one of the most devastating agricultural pests in the world, which is composed of numerous bieiypes. These biotypes show different biological traits with respect to host range,virus -transmission capabilities and insecticide resistance. In this study, the 45 Bemisia tabaci populations from 10 different regions of Shanghai were collected and analyzed based on the gene sequence of Mitochondrial cytochrome oxidase 1 ( mtDNA COI). The results show that the populations from Jiading, Jinshan and Xuhui districts were only Q biotype, and only B biotypes was found in Minhang district, but B and Q biotypes co - exist in other districts. Moreover, among the total 45 populations of Bemisia tabaci i-dentified in this study, 31 populations were Q biotype, 68. 9% proportion and B biotype 31. 1% respectively. In addition, most populations collected from greenhouse were Q biotype(87. 0% ). The results indicated that Q biotype spreads widely in Shanghai area and may replace the B biotype as a major crop pest in Shanghai area.

  15. 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

  16. 烟粉虱血细胞对白僵菌的防御反应%Defense Response of Hemolymph in Bemisia tabaci to Beauveria bessiana

    Institute of Scientific and Technical Information of China (English)

    任洁; 韩雪梅; 刘昭; 雷仲仁

    2013-01-01

    To identify the defense mechanism of Bemisia tabaci hemolymph against Beauveria bassiana,cellular immune responses of the infected 3rd instar nymph was investigated with optics microscope and Giemsa stain.The results showed that the invasion of Beauveria bassiana could bring about changes in the total numbers of host hemocytes.After 36 hours inoculation,the blastospores appeared in B. tabaci and the total numbers of host hemocytes were increased.At the same time, the blastospores were adsorbed to the surface of plamatocyte.60 hours after inoculation,the hyphal bodies were absorbed to the surface of granulocytes.More hyphal bodies were observed to the surface of granulocytes 96 hours after inoculation,and the insect body color had appeared the symptoms of infection,which means that the B. bassiana has broken the defense of B. tabaci.B. tabaci can only inhibit the invasion of B. basiana temporarily.%  为了探讨烟粉虱(Bemisia tabaci)血淋巴对白僵菌(Beauveria bassiana)的防御机制,利用吉姆萨染色法在光学显微镜下观察烟粉虱3龄若虫血细胞感染白僵菌后的免疫反应。结果表明:白僵菌的入侵可导致烟粉虱血细胞数量发生改变。体表接种36 h后,虫体内出现芽生孢子,血细胞数量开始增加,芽生孢子被吸附到浆血细胞表面;接种60 h后菌丝段吸附到粒血细胞表面;接种96 h后粒血细胞表面吸附大量菌丝段,此时昆虫体色已经呈现感染症状,说明真菌已经打破了烟粉虱的防御体系,烟粉虱幼虫血淋巴对白僵菌有短时间抑制。

  17. 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...

  18. Population suppression of Bemisia tabaci (Hemiptera:Aleyrodidae) using yellow sticky traps and Eretmocerus nr.rajasthanicus (Hymenoptera:Aphelinidae) on tomato plants in greenhouses

    Institute of Scientific and Technical Information of China (English)

    Xi-Shu Gu; Wen-Jun Bu; Wei-Hong Xu; Yi-Chuan Bai; Bai-Ming Liu; Tong-Xian Liu

    2008-01-01

    WeconductedthreeexperimentsformanagementofBemisiatabaci(Gennadius)biotype'B 'on tomatoes under greenhouse conditions:(i) vertically placing yellow sticky cards either parallel or perpendicular to tomato rows at a rate of 1 per 3-m row;(ii) releasing Eretmocerus sp.nr.rajasthanicus once at 30 adults/m2 in the high whitefly density greenhouses (> 10 adults/plant),or twice at 15 adults/m2 at a 5-day interval in the low whitefly density greenhouses (< 10 adults/plant);and (iii) using combinations of yellow sticky cards that were placed vertically parallel to tomato rows and parasitoids released once at 30/m2 in high whitefly density greenhouses or twice at 15/m2 at a 5-day interval in low whitefly density greenhouses.Our data show that yellow sticky cards trapped B.tabaci adults and significantly reduced whitefly populations on tomato.The yellow sticky cards that were placed parallel to tomato rows caught significantly more whitefly adults than those placed perpendicular to tomato rows on every sampling date.In the treatment where parasitoids were released once at 30/m2 in high whitefly density greenhouses,the number of live whitefly nymphs were reduced from 4.6/leaf to 2.9/leaf in 40 days as compared with those on untreated plants on which live whitefly nymphs increased from 4.4/leaf to 8.9/leaf.In the treatment where parasitoids were released twice at 15/m2 in low whitefly density greenhouses,the numbers of live nymphs ofB.tabaci on tomato leaves were reduced from 2.1/leaf to 1.7/leaf in 20 days as compared with those on untreated plants on which numbers of live nymphs of B.tabaci increased from 2.2/leaf to 4.5/leaf.In the treatment of yellow sticky cards and parasitoid release once at 30/m2 in high whitefly density greenhouses,the numbers of live nymphs of B.tabaci on tomato leaves were reduced from 7.2/leaf to 1.9/leaf,and in the treatment of yellow sticky cards and parasitoid release twice at 15/m2 at a 5-day interval at low whitefly density,the numbers of

  19. 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.

  20. Chemical composition and insecticidal activity of essential oils of two aromatic plants from Ivory Coast against Bemisia tabaci G. (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Tia, Etienne V; Adima, Augustin A; Niamké, Sébastien L; Jean, Gnago A; Martin, Thibaud; Lozano, Paul; Menut, Chantal

    2011-08-01

    Essential oils of aromatic plants with insecticidal properties are nowadays considered as alternative insecticides to protect cultures from attack by insect pest. The aims of the present work were to evaluate the toxicity of the essential oils vapors of two aromatic plants (Lippia multiflora Mold. and Aframomum latifolium K. Schum) against Bemisia tabaci and to characterize their chemical composition. The highest fumigant toxicity against B. tabaci adults was observed with the L. multiflora oil: by exposure to 0.4 microL/L air, the lethal time inducing 90% mortality (LT90) was below 2 hours for this essential oil whereas it reached 15 h in the case of the A. latifolium oil. Both oils were analyzed by GC-FID and GC-MS on two capillary columns. The oil of L. multiflora contained a majority of oxygenated terpenoids mainly represented by the two acyclic components linalool (46.6%) and (E)-nerolidol (16.5%); the oil of A. latifolium was dominated by hydrocarbonated terpenoids among them beta-pinene (51.6%) and beta-caryophyllene (12.3%) were the two major components.

  1. 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

  2. 10种杀虫剂对南京地区Q型烟粉虱的室内毒力测定%Indoor Toxicities of Ten Insecticides to Q -type Bemisia tabaci in Nanjing District

    Institute of Scientific and Technical Information of China (English)

    徐德进; 季英华; 顾中言; 徐广春; 许小龙; 董玉轩

    2011-01-01

    在室内测定了10种杀虫剂对南京地区Q型烟粉虱的毒力,为生产上科学选择杀虫剂品种提供依据.根据烟粉虱的虫态和虫龄分别设计毒力测定方法,结果表明:10种杀虫剂中阿维菌素、甲氨基阿维菌素苯甲酸盐、啶虫脒和印楝素对烟粉虱成虫、若虫毒力较高,测定的杀虫剂品种中仅印楝素和噻虫啉对烟粉虱卵表现出较好的杀伤作用;在南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,并配合使用对烟粉虱卵高效的杀虫剂品种.%In order to scientifically apply insecticides to control Q -type Bemisia tabaci in the production in Nanjing, the toxici-ties of ten insecticides to Q -type Bemisia tabaci in Nanjing district were tested in the laboratory, and different determination methods were designed according to the morphology and instar of Bemisia tabaci. The results indicated that the toxicities of Abamectin, Em-amectin benzoate, Acetamiprid and Azadirachtin to the adult and nymph were higher than those of the other insecticides tested in the experiments. Among the ten insecticides, only Azadirachtin and Thiacloprid exhibited high ovicidalactivity. Therefore, the application of the antibiotic insecticides with high sensitivity, the alternative use of the neonicotinoid pesticides, and the combined application of the insecticides with high ovicidalactivity were recommended in the control of Bemisia tabaci in Nanjing district.

  3. Virion stability is important for the circulative transmission of tomato yellow leaf curl sardinia virus by Bemisia tabaci, but virion access to salivary glands does not guarantee transmissibility.

    Science.gov (United States)

    Caciagli, Piero; Medina Piles, Vicente; Marian, Daniele; Vecchiati, Manuela; Masenga, Vera; Mason, Giovanna; Falcioni, Tania; Noris, Emanuela

    2009-06-01

    The capsid protein (CP) of the monopartite begomovirus Tomato yellow leaf curl Sardinia virus (TYLCSV), family Geminiviridae, is indispensable for plant infection and vector transmission. A region between amino acids 129 and 152 is critical for virion assembly and insect transmissibility. Two previously described mutants, one with a double Q129P Q134H mutation (PNHD) and another with a further D152E change (PNHE), were found nontransmissible (NT). Another NT mutant with a single N130D change (QDQD) was retrieved from a new mutational analysis. In this study, these three NT mutants and the wild-type (wt) virus were compared in their relationships with the whitefly vector Bemisia tabaci and the nonvector Trialeurodes vaporariorum. Retention kinetics of NT mutants were analyzed by quantitative dot blot hybridization in whiteflies fed on infected plants. The QDQD mutant, whose virions appeared nongeminate following purification, was hardly detectable in either whitefly species at any sampling time. The PNHD mutant was acquired and circulated in both whitefly species for up to 10 days, like the wt virus, while PNHE circulated in B. tabaci only. Using immunogold labeling, both PNHD and PNHE CPs were detected in B. tabaci salivary glands (SGs) like the wt virus, while no labeling was found in any whitefly tissue with the QDQD mutant. Significant inhibition of transmission of the wt virus was observed after prior feeding of the insects on plants infected with the PNHE mutant, but not on plants infected with the other mutants. Virion stability and ability to cross the SG barrier are necessary for TYLCSV transmission, but interactions with molecular components inside the SGs are also critical for transmissibility.

  4. 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

  5. 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.

  6. 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.

  7. Pest Management on Bemisia tabaci Using Trap Plants%利用诱集植物防治烟粉虱的研究

    Institute of Scientific and Technical Information of China (English)

    丁雪玲; 赵建伟; 姚凤銮; 郑宇; 何玉仙

    2015-01-01

    Experiments to examine the host selection of the pest,Bemisia tabaci ,was conducted in laboratory.The most preferred plant by the pests was used in a field test to determine its efficiency in attracting B .tabaci for an integrated pest management application.The results showed that B .tabaci strongly preferred the cucumber (Cucumis sativus ), followed by cabbage (Brassica oleracea ), tomato (Lycopersicon esculentum ), eggplant (Solanum melongena ), cowpea (Vigna sinensis ), kidney bean (Phaseolus vulgaris ), squash (Cucurbita moschata ),and loofah (Luffa cylindrical ),but was poorly attracted to soybean (Glycine max ),piemarker (Abutilon theophrasti )and pepper (Capsicum frutescens ).As a trap plant,cucumber was intercropped with soybeans in a field that attracted adult whiteflies at a rate of 90.2% with a pest control efficiency of 82.83%. Subsequently,several insecticides were applied on the cucumber plants showing varying degrees of control efficacy on adult whiteflies.Among the insecticides tested,22.4% spirotetramat SC,10% nitenpyram EC,10% bifenthrin EC and 25% pymetrozine WP showed greater control efficiencies of 82.72%,78.71%,67.39% and 74.34%, respectively,7 days after treatment.%通过选择性试验,研究烟粉虱的寄主选择性差异,进而开展诱集植物筛选及其对烟粉虱诱集效果的评价。结果表明,烟粉虱成虫明显嗜好黄瓜,然后依次为甘蓝、番茄、茄子、豇豆、四季豆、西葫芦、丝瓜,对毛豆、苘麻和辣椒的嗜好性较差;毛豆田间作黄瓜作为诱集植物对烟粉虱成虫的诱集效果达90.2%,防治效果为82.83%。配套施药试验结果表明,22.4%螺虫乙酯悬浮剂、10%烯啶虫胺水剂、10%联苯菊酯乳油和25%吡蚜酮可湿性粉剂能有效控制诱集植物黄瓜上的烟粉虱成虫,药后7 d 防治效果分别达82.72%、78.71%、67.39%和74.34%。

  8. 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.

  9. 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

  10. 吡蚜酮对烟粉虱取食干扰效应的探讨%Effect of pymetrozine interferes with feeding behaviour of Bemisia tabaci ( Homoptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    王海鸿; 雷仲仁; 岳梅; 李硕; 纪云亮

    2011-01-01

    采用甘兰叶片浸液法测定了吡蚜酮对烟粉虱Bemisia tabaci(Gennadius)成虫、卵、1龄若虫和3龄若虫的致死作用.在所测试的浓度范围(9.38~300 mg/L)内,烟粉虱若虫和成虫的校正死亡率均随吡蚜酮浓度的增大而顺次显著增大.取食75~150 mg/L、9.38~37.5 mg/l吡蚜酮处理叶片和清水处理叶片的存活成虫个体单头蜜露量(分别为0.37~0.42、0.59~0.72、1.48 mm2)间存在显著差异(P<0.05).用EPG技术研究了吡蚜酮对烟粉虱口针刺吸的不同阶段和取食活性的影响.接触低浓度吡蚜酮(75 mg/L)时,最初粉虱能够正常开始取食,但不能从韧皮部正常吸取汁液.高浓度的吡蚜酮(300 mg/L)抑制了口针向植物的插入.综合上述结果,说明吡蚜酮可望成为防治番茄黄曲叶病毒病载体-烟粉虱的重要药剂之一.%We tested the mortality and LC50 of pymetrozine against whiteflies using the cabbage leaf-disc dipping method. The concentration of pymetrozine ranged between 9. 38mg/L and 300mg/L and mortality was significantly dosage-dependent. There were significant differences in the honeydew quantities ( 0. 37 - 0. 42、0. 59 - 0. 72 and 1.48 mm2 ,respectively) of adults feeding on leaves dipped in 75 - 150、9. 38 -37.5 and 0 mg/L pymetrozine (P <0.05).The effect of pymetrozine on different phases of styler penetration and feeding activity of individual whiteflies was studied using the Electrical Penetration Graph technique (EPG). When low-concertration pymetrozine (75 mg/L) was applied to leaves,whiteflies started feeding normally. However, after some time they withdrew their stylets from the phloem.Higher concertrations of pymetrozine (300 mg/L) inhibited stylet insertion into the plant. Therefore, pymetrozine may be one of the most effective chemicals for the control of sweet-potato whiteflies, which are vectors of tomato yellow-leaf curl viruses.

  11. Characterization of acetylcholinesterases, and their genes, from the hemipteran species Myzus persicae (Sulzer), Aphis gossypii (Glover), Bemisia tabaci (Gennadius) and Trialeurodes vaporariorum (Westwood).

    Science.gov (United States)

    Javed, N; Viner, R; Williamson, M S; Field, L M; Devonshire, A L; Moores, G D

    2003-12-01

    Gene sequences encoding putative acetylcholinesterases have been reported for four hemipteran insect species. Although acetylcholinesterase insensitivity occurs in insecticide-resistant populations of each of these species, no mutations were detected in the gene sequences from the resistant insects. This, coupled with a series of experiments using novel reversible inhibitors to compare the biochemical characteristics of acetylcholinesterase from a range of insect species, showed that the cloned cDNA fragments are unlikely to encode the hemipteran synaptic acetylcholinesterases, and there is likely to be a second ace locus.

  12. 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.

  13. 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%.

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

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    Sheila Salles de Carvalho

    2015-01-01

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

  15. 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

  16. 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

  17. 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.

  18. Study on the Interspecific Competition Between Bemisia tabaci and Trialeurodes vaporariorum Under the Same Conversition%烟粉虱和温室白粉虱在相同生境下的种间竞争研究

    Institute of Scientific and Technical Information of China (English)

    郑长英; 冯志国; 王雅卉; 王思芳

    2012-01-01

    为确定烟粉虱(Bemisia tabaci)和温室白粉虱(Trialeurodes vaporariorum)在室内自然条件下对寄主植物的选择性和种间竞争。2008年研究了2种粉虱在茄子、黄瓜、番茄、辣椒4种寄主植物上的适应性和种间竞争,茄子上烟粉虱和温室白粉虱不同起始种群数量二者间的竞争,温室白粉虱对南瓜和茄子的喜好。结果表明:4种寄主植物上,相同基数的2种试虫,烟粉虱建立种群的能力大于温室白粉虱,在茄子上表现尤为明显;在茄子上不同种群基数的竞争条件下,烟粉虱最终可将温室白粉虱取代;温室白粉虱在养虫笼小生境下对南瓜的喜好略大于茄子。表明在同一生境条件下烟粉虱较温室白粉虱有更强的种间竞争能力。%This experiment studied on the interspecific competition between Bemisia tabaci and Trialeurodes vaporariorum and the selection of two pests to the eggplant,the cucumber,the tomato and the hot pepper in laboratory in 2008.For studying on the interspecific competition between the 2 pests,T.vaporariorum and B.tabaci were put the same number into the cage with one different host plant respectively and put two pests according to the different proportion into the cage with one eggplant.The selection of T.vaporariorum to pumpkin and eggplant was tested.The results showed that on the four kinds of host plants,the ability of building population of B.tabaci was higher than T.vaporariorum,especially on the eggplants;T.vaporariorum has been replaced by B.tabaci in no mater what propotion on eggplant;T.vaporariorum like pumpkins more than eggplants.It indicated that B.tabaci has higher competition ability than T.vaporariorum.

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

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    Hugh A. Smith

    2016-10-01

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

  20. A comparative study of the removal of endosymbionts in Bemisia tabaci biotypes B and Q using three antibiotics%三种抗生素对B型和Q型烟粉虱内共生菌的去除效果比较研究

    Institute of Scientific and Technical Information of China (English)

    苏奇; 潘慧鹏; 王少丽; 吴青君; 徐宝云; 张友军

    2012-01-01

    利用烟粉虱Bemisia tabaci (Gennadius)内共生菌特异性引物,研究了内共生菌在B、Q型烟粉虱种群中的分布和感染率,同时评价了3种不同的抗生素利福平、氨苄青霉素和硫酸卡那霉素分别在3种不同的浓度下(100.0、50.0及25.0 μg/mL)对烟粉虱内共生菌的去除效果.结果表明:B、Q型烟粉虱原生内共生细菌Portiera 的带菌率均为100.0%;B、Q型烟粉虱次生内共生菌Hamiltonella的带菌率分别为91.7%和100.0%;B型烟粉虱次生内共生菌Rickettsia的带菌率为87.5%,Q型为0;其它次生内共生菌在B、Q型烟粉虱中均未检测到.利福平、氨苄青霉素和硫酸卡那霉素在3种不同的浓度下均不能去除B、Q型烟粉虱Portiera;利福平、氨苄青霉素在3种不同的浓度下均能完全去除B型烟粉虱Rickettsia,硫酸卡那霉素在不同浓度下去除Rickettsia的效果不同;3种抗生素去除Hamiltonella的能力受抗生素种类以及浓度的影响.同一抗生素在不同浓度下去除Hamiltonella的效果均是100.0 μg/mL >50.0 μg/mL >25.0 μg/mL;不同浓度的抗生素去除Hamiltonella的效果均是利福平>氨苄青霉素>硫酸卡那霉素,各浓度与各抗生素之间的去除Hamiltonella的效果均具有显著性差异.%A PCR survey of endosymbionts in one B and one Q Bemisia tabaci biotype was conducted. Kanamycin sulfate, ampicillin trihydrate, and rifampicin were used to investigate the sensitivity of endosymbionts in the two biotypes to antibiotics. The results show that 100% of all individuals of the both biotypes had Portiera. Hamiltonella was also found in both biotypes, with an infection frequency of 91. 7% and 100.0%, respectively. Rickettsia was only detected in 87.5% of the B biotype. Other endosymbionts including Wolbachia, Fritschea, Arsenophonus, and Cardinium were not detected in either biotype. The three antibiotics failed to eliminated Portiera from any individual of the B and Q biotypes

  1. 温室粉虱和烟粉虱3个隐种中热激蛋白基因hsp70和hsp90含量的比较分析%Comparative analysis of the copy numbers of hsp70 and hsp90 in Trialeurodes vaporariorum and three cryptic species of Bemisia tabaci complex (Hemiptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    韦姣; 吕志创; 王韧; 万方浩

    2014-01-01

    [目的]昆虫适应新环境的能力与其对温度的耐受能力密切相关.热激蛋白HSP70和HSP90具有提高生物体温度耐受性的功能.烟粉虱Bemisia tabaci (Gennadius)不同隐种和不同种粉虱对温度的适应能力有差异,这与它们的热激蛋白基因拷贝数的差异可能相关.[方法]利用实时荧光定量PCR方法,检测入侵型烟粉虱MED隐种和MEAM1隐种、本地型烟粉虱AsiaⅡ1隐种以及温室粉虱Trialeurodes vaporariorum (Westwood)基因组DNA中热激蛋白基因hsp70和hsp90的拷贝数.[结果]不同种类的粉虱和烟粉虱不同隐种体内的hsp70和hsp90的含量均有较大差异,其中hsp70和hsp90拷贝数在入侵型烟粉虱MED和MEAM1隐种中含量较其他两种均高,而在土著种AsiaⅡ1隐种中含量最低,在温室粉虱中居中.此外,相同物种雌雄成虫hsp70和hsp90的拷贝数也不同,雌虫hsp70和hsp90拷贝数约为雄虫的2倍.[结论]不同种粉虱及烟粉虱不同隐种的hsp70和hsp90的拷贝数可能与其耐热性差异相关.本研究为解释不同种粉虱、烟粉虱不同隐种及其不同性别的耐热性差异机制提供了进一步的依据.

  2. Caracterização e avaliação de acilaçúcar sintético no comportamento da mosca-branca Bemisia Tabaci (Gennadius, 1886 biótipo B (Hemiptera: Aleyrodidae em tomateiro Characterization and evaluation of synthetic acylsugar on the behavior of the whitefly Bemisia tabaci (Gennadius, 1886 b biotype (hemiptera: aleyrodidae in tomato plant

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    Vanisse de Fátima Silva

    2008-10-01

    Full Text Available O cultivo de tomate é uma atividade de destaque no Brasil em termos de produção e consumo e os estados de Goiás, São Paulo e Minas Gerais são os principais produtores. Visando a desenvolver novos compostos com função inseticida, este trabalho foi desenvolvido com o objetivo de sintetizar acilaçúcares, aleloquímico presente nas folhas que conferem resistência natural ao tomateiro Lycopersicon pennellii e avaliar seus efeitos no comportamento da mosca-branca. O delineamento utilizado foi o inteiramente casualizado, com cinco tratamentos e cinco repetições. Os ensaios consistiram dos seguintes tratamentos: plantas de tomate cv. Santa Clara pulverizadas com água pura (testemunha; plantas de tomate cv. Santa Clara pulverizadas com acilaçúcar 01 (sintetizado a partir de sacarose; plantas de tomate cv. Santa Clara pulverizadas com acilaçúcar 02 (sintetizado a partir da glicose com cloreto de zinco como catalisador; plantas de tomate cv. Santa Clara pulverizadas com acilaçúcar 03 (sintetizado a partir da glicose com acetato de sódio como catalisador e plantas de tomate Lycopersicon pennellii pulverizadas com água pura. A concentração do composto utilizada foi de 0,05%. Os resultados obtidos mostraram que o acilaçúcar 03 reduz a oviposição do inseto no tomateiro. Todavia, se fazem necessários estudos mais detalhados para se avaliar melhor a ação desse composto sobre a mosca-branca.Tomato plant growing is an important activity in Brazil both in production and in consumption, and the states of Goiás, São Paulo and Minas Gerais are the main producing states. In order to develop new products with insecticide activity, this work was developed with the aim synthesizing acylsugar, alelochemical present in the leaves that give natural resistance to the tomato plant Lycopersicon pennellii evaluating and its effects on the behavior of the whitefly. The layout used was a completely randomized design, with five treatments and five repetitions. The trials consisted of the following treatments: Santa Clara tomato plants cultivar sprayed with pure water (control; Santa Clara tomato plants cultivar sprayed with acylsugar 01 (synthesized starting from sucrose; Santa Clara plants of tomato cultivar sprayed with acylsugar 02 (synthesized starting from the glucose with chloride of zinc as catalyst; tomato plants Santa Clara cultivar sprayed with acylsugar 03 (synthesized starting from the glucose with acetate of sodium as catalyst and tomato plants Lycopersicon pennellii splayed with pure water. The concentration of the composition used was of 0.05%. The results showed that the acylsugar 03 reduce the egg laying activity of the whitefly in the tomato plant. However, it seems necessary to deepen studies to evaluate the action of this product on the whitefly behavior.

  3. 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

  4. 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.

  5. 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

  6. Control Effects of Yellow Sticky Trap (YST) to Bemisia tabaci in the Greenhouses in Turpan Area%黄板诱杀对设施蔬菜烟粉虱控制作用研究

    Institute of Scientific and Technical Information of China (English)

    陈丹; 张以和; 热孜万古力; 米日古丽; 杨媚; 潘卫萍; 马德英

    2012-01-01

    [目的]减少农药的使用,提高农产品质量安全.[方法]研究不同黄板间距及色板颜色对温室烟粉虱的诱杀作用.[结果]3 m间距黄板对烟粉虱的诱杀效果最好,30 d后虫口减退率高达99.52%;其次是6和9m间距,虫口减退率分别达87.27%和44.92%.以植株上烟粉虱虫口减退率对黄板间距进行拟合,得到回归方程Y=-1.7404X2+11.392 X+79.874(R2=1).表明黄板间距大于3 m以后,随着间距的增大,植株上烟粉虱的虫口减退率降低.3~5m间距植株上烟粉虱成虫的虫口减退率下降趋势缓慢,是设施内经济有效的黄板间距.两种黄板颜色的比较表明,金黄色板和橘黄色板对烟粉虱均有明显的诱杀作用.金黄色板对烟粉虱的诱集效果更好,与橘黄色板间差异显著.[结论]在设施烟粉虱发生初期虫口密度较低时,即虫口密度在平均每片叶不超过5头的时候,以3~5m间距悬挂2列金黄色板,对温室蔬菜定植后早期发生的烟粉虱可以获得理想的控制效果.%[Objective] In order to reduce pesticides amount and enhance the the quality and safety of farm produce. [ Method ] The traping and killing effect of different densities of yellow sticky trap as well as color differences are studied in greenhouses to Bemisia tabaci. [Result] Results showed that the traping and killing effect of 3 m space between yellow sticky traps is the best with 99. 5% population decline rate after 30 d, lined with 6 m and 9 m at 87. 27% and 44. 92% population decline rate, respectively. Combining population decline rate of B. Tabaci on plant and the space between yellow traps fitted the regression equation of Y = -1.740 4 X2 + 11. 392 X + 79. 874 (R2 = 1). It suggested that the population decline rate of B. Tabaci on plant decreased along with the increase of spaces between yellow sticky trap after 3 m. Whereas the population decline rate of B. Tabaci on plant decreased very slowly in distance of 3 - 5 m. This may be the

  7. 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

  8. Effects of calcium fertilizer on the development, survival, and feeding of B-biotype Bemisia tabaci on Euphorbia pulcherrima%钙肥对B型烟粉虱发育、存活及取食为害的影响

    Institute of Scientific and Technical Information of China (English)

    黄俊; 张娟; 郁永明; 刘建新; 李明江; 朱开元

    2012-01-01

    This paper studied the development, survival, and feeding of B-biotype Bemisia tabaci on Euphorbia pulcherrima under the conditions of 26±1 ℃ 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 (qp) , light use efficiency (α) , maximum photosynthesis rate (rETRmax ) , and tolerance to light (Ik) decreased significantly, while the non-photochemical quenching coefficient (NPQ) had a significant increase. After applying calcium fertilizer, the plant leaf photoinhibition parameter (β) , rETRmax,and Ik had less difference with the 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.%以清水为对照,研究了施用钙肥后一品红植株对B型烟粉虱发育、存活和取食为害的影响.结果表明:在温度(26±1)℃、相对湿度60%~80%条件下,钙肥处理的一品红植株上的B型烟粉虱在发育历期上与对照存在显著差异,卵期明显缩短,各龄若虫期延长,从卵到成虫的发育时间为20.18 d,而对照为18.72 d;但钙肥处理对B型烟粉虱各虫态的存活率无显著影响.B型烟粉虱的取食为害诱导了一品红叶片叶

  9. 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

  10. The Susceptibility of Bemisia Tabaci and Trialeurodes vaporariorum to Used Insecticides%常用杀虫剂对烟粉虱和温室白粉虱的毒力测定

    Institute of Scientific and Technical Information of China (English)

    王俊平; 张爱霞; 郑长英; 杨现明

    2012-01-01

    The susceptibility of adults of Bemisia tabaci and Trialeurodes vaporariorum to 3 insecticides, imidaclo-prid, beta cypermethrin and dimethyl - dichloro - vinyl - phosphate was studied with the method of leaf - dip bio-assay. Results suggested that the susceptibility of B. tabaci and T. vaporariorum, collected from same areas in Shandong to 3 insecticides, had been approximately same. High variability in the susceptibility to dimethyl - dichloro - vinyl - phosphate, beta cypermethrin and imidacloprid was noted, ranging from low ( LC50 = 1383 -1965mg/L) to medium ( LC50 = 124 - 153mg/L) to high lethal concentration 50 ( LC50 = 60 - 95mg/L). But T. vaporariorum (Qingdao) to imidacloprid had generated the medium level resistance. So we should streng their resistance monitoring.%2007~2008年通过琼脂浸叶法测定山东不同地区烟粉虱和温室白粉虱对吡虫啉、高效氯氰菊酯和敌敌畏3种杀虫剂的敏感性.同一地区内,烟粉虱和温室白粉虱对3种杀虫剂敏感度基本相同.温室白粉虱和烟粉虱成虫对吡虫啉的敏感度高,LC50为60 ~ 95mg/L;其次是高效氯氰菊酯,LC50为124~ 153mg/L;最低为敌敌畏,LC50为1383~1965mg/L.但是青岛温室白粉虱种群对吡虫啉抗性程度已达中等水平,应加强其抗药性监测.

  11. Insecticidal Activity of 5% Beta-cypermethrin and Acetamiprid Hot Fogging Concentrate against Bemisia tabaci%5%高氯•啶虫脒热雾剂对烟粉虱的杀虫活性

    Institute of Scientific and Technical Information of China (English)

    冯岗; 闫超; 叶火春; 袁恩林; 张静

    2015-01-01

    Insecticidal activity of 5% beta-cypermethrin and acetamiprid hot fogging concentrate against Bemisia tabaci were investigated in the laboratory and field. The results showed that the preparation has high toxicity against the adult of B. tabaci with linear regress equation of 4.007 8+1.457 7x and LC50 of 4.79 mg/mL, which displayed that beta-cypermethrin exhibited strong synergistic effect on acetamiprid, the co-toxicity coefficient (CTC) being as high as 186. In dealing with a dose of 2.5 to 7.5 g/667 m2, he corrected efficacy can reach more than 75% when examined at 7th day after treatment. 5%beta-cypermethrin and acetamiprid hot fogging concentrate as a insecticide controlling B. tabaci is therefore promising.%于室内和田间测定了5%高氯•啶虫脒热雾剂对烟粉虱的杀虫活性。结果表明:5%高氯•啶虫脒热雾剂对烟粉虱成虫具有很强的毒杀作用,其毒力回归方程为4.0078+1.4577x, LC50值为4.79 mg/L,说明氯氰菊酯对啶虫脒具有显著的增效作用,其共毒系数(CTC)为186;田间防治试验显示,5%高氯•啶虫脒热雾剂对烟粉虱具有明显的控制作用,在处理剂量为37.5~112.5 g/hm2时,药后7 d的防治效果可达75%以上。5%高氯•啶虫脒热雾剂可作为防治烟粉虱的专用药剂。

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. 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

  17. 烟粉虱 B 型和 Q 型竞争能力的室内比较分析%Comparative Analysis of the Competitiveness Between B and Q Biotypes of Bemisia tabaci Under Laboratory Conditions

    Institute of Scientific and Technical Information of China (English)

    卢少华; 李静静; 刘明杨; 白润娥; 汤清波; 闫凤鸣

    2015-01-01

    [Objective]B and Q biotypes of Bemisia tabaci are two invasive cryptic species in China. The field investigation showed that Q biotype is becoming the dominant replacing B biotype in most areas of China in recent years. It is necessary to research the mechanisms and the influencing factor of the B. tabaci biotype replacement. Differences of feeding behaviors and competitiveness between B and Q biotypes of B. tabaci were compared under laboratory conditions, aiming to provide a basis for effective management of whiteflies. [Method] The stylet probing behaviors of B and Q biotypes of B. tabaci on Cucumis sativus were recorded and analyzed by using the electrical penetration graph (EPG) technique. The competitiveness of the two biotypes of B. tabaci was compared by investigating the population dynamics of the two biotypes in six successive generations on C. sativus.[Result] EPG results showed that B biotype B. tabaci had significantly more total number of probes (P=0.020) and longer total duration of probes (P=0.048) than Q biotype, and during the 2nd phase, the percentage of E was mainly lower (P=0.001) in B biotype than Q biotype, but there was no significant difference in percentage of probing duration between the two biotypes. Q biotype had significantly more total number of Pd (potential drop) (P=0.012) and longer total duration of Pd (P=0.016). For comparison of males and females in the same biotype, B biotype females were significantly lower than B biotype males in the percentage of Np (P=0.035) and the percentage of E (P0.05) in the 3rd phase between males and females of B biotype. For Q biotype, females not only had significantly higher percentage of probing duration (P=0.031) in the 2nd phase than Q biotype males, but also had significantly longer total duration of probes (P=0.039). Q biotype females had significantly shorter total duration of Np (P=0.038) than Q biotype males. There were no significant differences between males of B and Q biotypes for all

  18. Control effects and toxicities of six insecticides against Bemisia tabaci Q biotype%6种杀虫剂对Q型烟粉虱的田间防治效果及抗性测定

    Institute of Scientific and Technical Information of China (English)

    边海霞; 穆常青; 郭晓军; 罗晨; 郅军锐

    2011-01-01

    Impacts of six common insecticides on Bemisia tabaci Q-biotype in field efficiency trials and bioassays were tested with cucumber. The results showed that the corrected mortality of Q-biotype whiteflies was 78. 8% three days after abamectin was used. The corrected mortality by oxymatrine ? Prosuler was 65.1%, and the others were less than 45%. The mortality gradually decreased and had no significant differences between different insecticides tested after seven days. Compared with the B-biotype whitefly, Q-biotype developed higher resistance level to abamectin, matrine, acetamiprid, imidacloprid, oxymatrine ? Prosuler and cypermethrin. Attention should be paid to selecting appropriate pesticides to prevent Q-Biotype whiteflies on cucumber. The six insecticides used at present induced different levels of resistance.%本文测试了6种常用杀虫剂对黄瓜上Q型烟粉虱的田间防治效果,并进行室内毒力测定,以确定Q型烟粉虱对不同药剂的抗性.结果表明,施药后第3天,阿维菌素防治效果达78.8%,其次为苦参·内酯,防效达65.1%,其他药剂防效低于45%;施药7d后,6种供试杀虫剂防效均下降到45%以下,且药剂间的差异不显著.毒力测定显示,Q型烟粉虱对6种常用杀虫剂均产生不同程度的抗性,且抗性水平高于B型.其中,Q型对高效氯氰菊酯抗性(抗性倍数47.69)显著高于B型(抗性倍数7.19);对阿维菌素抗性则相对较低,抗性指数仅为4.40;对苦参碱、啶虫脒和吡虫啉的抗性居中(抗性倍数4.57~9.44).

  19. Ultra-structure of the antennal, stylet, and tarsal sensilla of three whiteflies: Bemisia tabaci , Trialeurodes vaporariorum ,Alenrocybotns indice ( Homoptera: A!eyrodidae)%三种粉虱触角、口针及跗节感受器的超微结构观察

    Institute of Scientific and Technical Information of China (English)

    洪慧金; 任顺祥; 杜予州; 王联德

    2011-01-01

    Scanning electron microspcopy was used to reveal the morphology and detailed ultra-structure of the antenna, stylet, and tarsal sensilla of three whiteflies; Bemisia tabaci, Trialeurodes vaporariorum, Alenrocybotns indice.All three species have microtrichia and 2 sensilla, i.e. chaetae sensilla and basiconic sensilla on the antennae. B.tabaci has 2 other types of sensilla on the antennae: campaniform sensilla and coebconic sensilla, but no campaniform sensilla were found on the on the antennae of T. vaporariorum and A. indice. All three species have similar morphological characteristics of microtrichia and chaetae sensilla on stylet, and tams.%对烟粉虱Bemisia tabaci、温室白粉虱Trialeurodes vaporariorum和禾粉虱Aleurocybotus indicus 3种粉虱的触角、口针及跗节感受器的超微结构进行了观察.利用扫描电镜观察了烟粉虱、温室白粉虱和禾粉虱3种粉虱触角、口针及跗节化学感受器的类型和分布,进行了比较.3种粉虱触角上都有刚毛感受器、锥形感受器2种感受器和微毛,烟粉虱触角还有钟形感受器和腔锥感受器;温室白粉虱和禾粉虱触角均没有发现钟形感受器;3种粉虱的口针和跗节上均只有刚毛感受器和微毛,且形态结构相似.

  20. 米尔贝霉素、乐平霉素及其他40种农药防治烟粉虱的特性比较%A Comparative Study of Characteristics of Milbemycins, Lepimetin and other 40 Kinds of Pesticides to Control Bemisia tabaci

    Institute of Scientific and Technical Information of China (English)

    向春华; 王相晶; 向文胜

    2014-01-01

    综述了米尔贝霉素、乐平霉素等42种农药对烟粉虱防治特性以及42种农药对烟粉虱3龄幼虫、成虫、孵化卵的毒性。相对于其他40种化学农药,米尔贝霉素、乐平霉素防治浓度低且高效,能很好地抑制粉虱卵的孵化以及雌性成虫粉虱产卵,对烟粉虱拟寄生物的影响极小,具有无互交抗性、安全等特性。此试验为选择合适的农药防治烟粉虱提供了参考。%The preventive characteristics of milbemectin, lepimectin and the other 40 kinds of pesticides on Bemisia tabaci and the toxicity of milbemectin, lepimectin on Bemisia tabaci with the other 40 kinds of pesticides tested on third stadium larvae, adult whiteflies and hatching were reviewed. Compared to other 40 kinds of chemical pesticides, milbemycins and lepimectin showed a low concentration and high efficiency, have a good effect in inhibition of eggs hatching and the number of adult female-whitefly lay eggs, have minimal impact on parasitoid intended of whitefly, no mutual cross-resistance and have high security. Therefore, it provides a clue for selecting appropriate pesticides to control whiteflies.

  1. Preliminary research on the distribution and transmission efficiency of Rickettsia, an endosymbiont of whitefly Bemisia tabaci%烟粉虱内共生菌 Rickettsia 在植物体内的分布及转移效率初探

    Institute of Scientific and Technical Information of China (English)

    安璇; 李翌菡; 李绍建; 郭长飞; 任顺祥; 邱宝利

    2015-01-01

    【目的】检测 Q 型烟粉虱 Bemisia tabaci (Gennadius)体内 Rickettsia 的感染情况,研究分析Rickettsia 共生菌经烟粉虱传入豇豆植物后的分布、转移效率等。【方法】以 Q 型烟粉虱为实验材料,利用常规 PCR 及荧光原位杂交技术(FISH),检测了烟粉虱体内 Rickettsia 的感染率,以及 Rickettsia 传入豇豆植物体内后的存留情况。【结果】 Q 型烟粉虱可以通过取食将 Rickettsia 传至豇豆植株内;接虫数量与 Rickettsia传入效率及其在取食部位相邻的下部叶片中检测到的起始时间呈负相关;Rickettsia 经烟粉虱取食传入豇豆叶片后,集中分布在叶片的韧皮部筛管中;基于16S rRNA 的系统发育分析结果表明,Q 型烟粉虱体内的Rickettsia 与经取食传入豇豆叶片的 Rickettsia 高度同源。【结论】 Rickettsia 可以通过烟粉虱的取食传入植物体内,并且可以在相邻叶片之间转移传播,Rickettsia 在由寄主昆虫向植株传播过程中高度保守。%Objectives] To detect the infection of Bemisia tabaci by Rickettsia, and the distribution and dissemination of Rickettsia after its transmission to cowpea leaves through whitefly feeding. [Methods] Infection of the B. tabaci Q biotype by Rickettsia, and its persistence in cowpea plants, were detected by PCR and fluoresent in situ hybridization (FISH). [Results] The distribution of Rickettsia was limited to the phloem vessels of cowpea leaves, Rickettsia could move along the vessels between different leaves, and its efficiency of dissemination was highly related to the initial population size of Rickettsia-positive B. tabaci individuals that fed on the cowpea leaves. Phylogenetic analysis based on 16S rRNA variation showed that Rickettsia in cowpea plants and whiteflies was 100% identical. [Conclusion] Rickettsia can be horizontally transmitted to cowpea plants through the feeding of the B. tabaci Q biotype and little genetic variation

  2. Effects of host plants on the growth and development, trehalose content and two enzyme activities of Q-biotype Bemisia tabaci%寄主植物对Q型烟粉虱生长发育、海藻糖含量及2种酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    谭永安; 肖留斌; 孙洋; 柏立新

    2012-01-01

    This experiment was conducted to determine the sizes of nymph, developmental durations, survival rates, content of trehalose and two enzyme activities for Q-biotype Bemisia tabaci fed on tomato, cucumber, cotton, pi-emarker. The sizes of Q-biotype B. tabaci nymphs on tomato and cucumbe were bigger than those on cotton and piemarker. The duration of Q-biotype B. tabaci nymphs on tomato was the shortest (17. 01 d) , followed by cucumber (18. 25 d ) , piemarker (20.31 d), cotton (20.57 d). The survival rates of Q-biotype B. tabaci on tomato, cucumber, cotton, and piemarker were 63. 71% , 61. 33% , 53. 77% and 51. 76% respectively. Tomato and cucumber were in favor of the Q-biotype populations breeding compared to cotton and piemarker, and adult longevity and single female spawning quantity on tomato , cucumber, cotton, and piemarker were respectively 24. 55 d and 268. 20 grains, 24.65 d and 202. 65 grains, 23.30 d and 173. 45 grains, 17. 10 d and 146. 70 grains. The trehalose content of the Q-biotype Bemisia tabaci fed on tomato was the highest (9. 38 (μg per nymph) , and that fed on cotton was the lowest (7. 15 μg per nymph) , but there was no positive correlation between trehalase activity and trehalose content. The alkaline phosphatase activity of the Q-biotype Bemisia tabaci fed on tomato was the highest [ 58. 57 OD/( min · ml) ]. In a word, tomato was the best host plant for Q-biotype B. tabaci.%以番茄、黄瓜、棉花及苘麻为供试寄主,测定了取食这4种寄主后的Q型烟粉虱的体型、发育历期、存活率等生物学参数与海藻糖含量及2种酶活性.结果表明:Q型烟粉虱若虫在番茄和黄瓜上的体型大于棉花和苘麻上的;在番茄上的若虫历期最短(17.01 d),其余依次为黄瓜(18.25 d)、苘麻(20.31 d)、棉花(20.57 d);Q型烟粉虱在番茄、黄瓜、棉花及苘麻上存活率分别为63.71%、61.33%、53.77%和51.76%;与棉花和苘麻相比,番茄和黄瓜明显有利于Q型烟粉虱

  3. 短时高温暴露对Q型烟粉虱成虫存活和生殖适应性的影响%Effects of Brief Exposure to High Temperature on Survival and Fecundity of Bemisia tabaci Q-biotype(Homoptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    崔旭红; 徐建信; 李晓宇; 蔡冲

    2011-01-01

    The effects of brief exposure to high temperature on survival and fecundity of Bemisia tabaci Q-biotype, (Homoptera: Aleyrodidae) were studied in the laborary condition to understand occasional changes in the biological characteristic of whitefly species encountered high temperature stress. The survival rate,reproduction and survival rate from egg to adult of F1 progeny of B. tabaci Q-biotype were evaluated after the adults were exposed to five degrees of temperature, 37, 39, 41, 43, 45℃, for 1 hour. The survival rates of adults of B. tabaci Q-biotype decreased with the increase of temperature. Within the range of 37℃ to 45℃, the survival rate of B. tsbaci Q-Biotype adults decreased from 100% to 21.4%,. Adult survival was significantiy affected when they were exposed at 41℃ or higher temperature. Female oviposition was not significantly different when adults were heat-exposured at all temperatures. However, the total survival rate from egg to adult of F1 progeny that produced by heated adults of B. tabaci Q-biotype decreased from 71.3% to 31.3%.The percentages of F1 offspring developing to adults were significantly affected when temperature increased to 41℃.The adults of B. tabaci Q-biotype has strong adaptability to high temperature, which could facilitate the population of B. tabaci Q-Biotype development in hot seasons%为了明确短时高温暴露对Q型烟粉虱成虫存活及生殖适应性的影响,将Q型烟粉虱成虫在不同温度(37、39、41、43、45℃)下暴露l h后研究了成虫存活率、产卵量及F1代存活率的变化.结果表明,Q型烟粉虱在37~45℃范围内暴露1 h后,成虫存活率由100%下降到21.4%,41℃及以上高温对Q型烟粉虱成虫存活率有显著影响;高温暴露后Q型烟粉虱成虫产卵量与对照相比没有显著差异,但F1代的存活率随着暴露温度的升高由71.3%下降到31.3%,在41℃及以上高温下暴露1 h后Q型烟粉虱F1的存活率显著下降.Q型烟粉虱对高

  4. 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.

  5. Transmission of Cry1Ac from transgenic Bt cotton to the predatory ladybug Propylaea japonica via the whitefly Bemisia tabaci%转Bt基因棉花中Cry1Ac蛋白经烟粉虱途径向龟纹瓢虫的传递

    Institute of Scientific and Technical Information of China (English)

    周福才; 顾爱祥; 杨益众; 苏宏华; 胡其靖; 杨爱民

    2015-01-01

    白可以消减,但在10 d时间内龟纹瓢虫体内仍会有Cry1Ac残留。%Objectives] The whitefly, Bemisia tabaci, is an economically important, non-target pest of Bt transgenic cotton. In this study, we examined the transmission of Cry1Ac from transgenic Bt cotton to the predatory ladybug, Propylaea japonica, (a natural enemy of the whitefly) in an effort to better evaluate the ecological safety of transgenic Bt cotton. [Methods] We used an enzyme linked immunosorbent assay (ELISA) to compare Cry1Ac levels in B. tabaci fed on the leaves of the conventional cotton cultivars SM3, SM33, and SY321 to those fed on the Bt transgenic cotton lines GK12, XM33B, and SGK321. [Results] Cry1Ac was detected in the adults, nymphs and honeydew of B. tabaci fed on Bt transgenic cotton. Cry1Ac was also detected in P. japonica that fed on these B. tabaci after just one day of feeding on B. tabaci nymphs that had consumed Bt transgenic cotton. The Cry1Ac content of P. japonica increased with increased with the duration of feeding, then stabilized after 6 to 8 days. The Cry1Ac content of P. japonica differed depending on the transgenic cotton line on which B. tabaci had fed. Although the Cry1Ac content of P. japonica declined when these were no longer exposed to food containing Cry1Ac, it did not disappear completely. The results of this study suggest that Cry1Ac from Bt transgenic cotton can be transferred to P. japonica through B. tabaci, and that B. tabaci can accumulate Cry1Ac. Cry1Ac levels in P. japonica eventually plateau;the speed of Cry1Ac accumulation in P. japonica, but not its saturation capacity, is related to the Cry1Ac content of their food. [Conclusion] Cry1Ac from Bt transgenic cotton can be transferred to P. japonica through B. tabaci, and B. tabaci can accumulate Cry1Ac. Cry1Ac levels in P. japonica plateau after 6 to 8 days; the speed of Cry1Ac accumulation in P. japonica, but not its saturation capacity, is related to the Cry1Ac content of their food.

  6. 烟粉虱MEAM1隐种漆酶-1基因全长cDNA克隆、序列分析与组织表达%Molecular cloning, sequence analysis and expression of a laccase-1 gene from Bemisia tabaci Middle East-Asia Minor 1 (Hemiptera:Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    杨春红; 彭露; 郭建洋; 严盈; 万方浩; 王进军

    2013-01-01

    多酚氧化酶是多种刺吸式昆虫唾液中的关键酶类,可以通过干扰寄主植物正常的氧化还原反应来调控食物来源使其更有利于昆虫本身.昆虫体内的漆酶-1属于多酚氧化酶家族,被认为参与昆虫取食过程中的金属离子代谢、降解植物次生有毒物质以及免疫防御等生理活动.为研究漆酶-1基因在烟粉虱MEAM1隐种Bemisia tabaciMiddle East-Asia Minor 1组织中的功能,利用RACE技术首次获得了烟粉虱MEAMI隐种漆酶-1(laccase-1,lac-1)基因的cDNA全长序列,命名为Btlac-1(GenBank登录号:JQ966215).结果表明,该基因含有一个2 733 bp的开放阅读框,编码910个氨基酸,其编码产物含有3个Cu-oxidase功能域,属于蓝多铜氧化酶家族成员.同源性比较分析表明,Btlac-1与黑尾叶蝉Nephotettix cincticeps和豌豆蚜Acyrthosiphon pisum的lac-1编码的氨基酸序列一致性达58%.Btlac-1在不同组织和发育时期的转录表达分析表明,Btlac-1在烟粉虱MEAM1隐种中肠中的转录水平最高,显著高于头胸部和腹部组织中,且在各个发育时期均有表达,在成虫期的表达水平较高.该结果为进一步明确lac-1在烟粉虱取食过程的生理作用奠定基础,也为探讨刺吸式昆虫与植物相互作用机制提供理论依据.%Polyphenol oxidase is the predominant enzyme in saliva of piercing-sucking insects. It can interfere with the normal oxidation-reduction reaction in host plants of insects and make food source more acceptable for itself. Insect laccase-1 (lac-1) belongs to the polyphenol oxidase family, and it has been verified that it is involved in the iron homeostasis, immune defense and detoxification. But the function of lac-1 in Bemisia tabaci is not clear. To determine the function of lac-1 gene in different tissues of Bemisia tabaci Middle East-Asia Minor 1 ( MEAM1) , lac-1 gene in B. tabaci MEAM1 was cloned using RACE method and named Btlac-l (GenBank accession no. JQ966215). Btlac

  7. 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

  8. Biotype distribution and phylogenetic analysis of Bemisia tabaci populations in main cotton planting areas in Hubei Province%湖北省棉花主产区烟粉虱生物型分布及系统发育分析

    Institute of Scientific and Technical Information of China (English)

    周新改; 马伟华; 刘美刚; 杨小红; 王沫

    2011-01-01

    [Objective] To understand the biotypes of Bemisia tabaci of cotton in main planting areas of Wuhan, Jingzhou, Xiaogan, Suizhou and Wuxue in Hubei Province. [Method] In this study, PCR-RFLP of mtCOI and gene sequencing method were used to identify the biotypes of whitefly field populations from main cotton planting areas in Hubei Province, and phylogenetic analysis of them was also conducted. [Result] The Q biotype was dominant in the field populations, while the B biotype was dominant in greenhouse populations. In addition, ZHJ1 biotype was also identified in Wuxue population. Phylogenetic analysis showed that populations from main cotton planting areas in Hubei Province were always homologous with populations from most other provinces in China. [Conclusion] The results may provide a reference for the control of B. Tabaci in Hubei Province.%[目的]明确武汉、荆州、孝感、随州、武穴5个棉花主产区烟粉虱生物型组成.[方法]通过以线粒体细胞色素氧化酶Ⅰ(mitochondrial cytochrome oxidase I,mtCOI)为基础的PCR-RFLP和基因测序的方法,鉴定湖北5个棉花主产区烟粉虱地理种群的生物型组成,并分析5个地理种群与其他省种群的系统发育关系.[结果]Q型烟粉虱为湖北省棉花主产区的优势种群,而武汉温室种群则均为B型烟粉虱,土著生物型ZHJ1型在大田中略有分布;系统发育分析表明,湖北省棉花主产区B型和Q型烟粉虱种群均与中国其他多个省的烟粉虱种群亲缘关系较近.[结论]本文研究结果可以为湖北省5个棉花主产区烟粉虱的有效防治提供参考.

  9. 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

  10. Female Reproductive System ofEretmocerus hayati (Zolnerowich & Rose) and Encarsia sophia (Girault & Dodd), Parasitoids of Bemisia tabaci (Gennadius)%海氏桨角蚜小蜂和浅黄恩蚜小蜂雌性生殖系统的解剖结构

    Institute of Scientific and Technical Information of China (English)

    冀禄禄; 杨念婉; 万方浩; 李照会

    2012-01-01

    Reproductive organ structures of Eretmocerus hayati (Zolnerowich & Rose) and Encarsia sophia (Girault & Dodd), parasitoids of Bemisia tabaci (Gennadius), were described in this paper. Both parasitoid females have two ovaries, each consisting of three ovarioles. Mature ova could be observed in the ovaries of 6 h-old females and the number of mature ova increased in 24 h-old females, indicating that these two parasitoids were synovigenic parasitoids. Moreover, the number of mature ova in Er hayati was higher than that in En. sophia whether the female was 6 or 24 h-old. The results were coincident with what we found in oviposition experiment that the 24 h-old Er. hayati female parasitized more hosts than En. sophia, but fed less.%首次对烟粉虱的寄生蜂海氏桨角蚜小蜂Eretmocerus hayati(Zolnerowich&Rose)和浅黄恩蚜小蜂Encarsia sophia(Girault&Dodd)的雌性生殖系统结构进行了研究。两种小蜂的卵巢均由6条卵巢管构成,雌蜂羽化后卵巢内有部分成熟卵,而羽化后24 h的成熟卵量较羽化后6 h有所增加,两种寄生蜂均是同步卵(synovigenic)类寄生蜂;海氏桨角蚜小蜂羽化6 h和24 h后体内成熟卵的数量均显著高于浅黄恩蚜小蜂,这与海氏桨角蚜小蜂24 h雌蜂的寄生量显著高于浅黄恩蚜小蜂,而寄主取食量却低于浅黄恩蚜小蜂的结果一致。

  11. 益害虫比对沙巴拟刀角瓢虫与越南斧瓢虫捕食烟粉虱行为的影响%Effects of the pest-natural enemy ratio on the predatory behavior of Serangiella sababensis and Axinoscymnus apioides (Coleoptera: Coccinellidae), two predators of Bemisia tabaci (Homoptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    苗静; 邱宝利; 任顺祥

    2010-01-01

    在实验室条件下研究了烟粉虱Bemisia tabaci Gennadius若虫不同密度、既定烟粉虱密度不同天敌数量两种条件下,沙巴拟刀角瓢虫Serangiella sababensis Sasaji和越南斧瓢虫Axinoscymnus apioides Kuznetsov & Ren的捕食行为.研究结果表明,但烟粉虱若虫密度从5增加到40头/cm2,沙巴拟刀角瓢虫和越南斧瓢虫搜寻猎物的时间,随着粉虱密度的增加而逐渐减少;取食猎物的时间,随着粉虱密度的增加而逐渐增加;对烟粉虱若虫的取食量也随密度的增加呈上升趋势.两种瓢虫相比,在既定猎物密度的情况下,刀角瓢虫搜寻、取食烟粉虱的时间要显著长于斧瓢虫所用的时间,但对烟粉虱的取食量明显低斧瓢虫的取食量.在固定粉虱数量的情况下,当瓢虫数量从1头增加到3头时,单头刀角瓢虫和斧瓢虫对烟粉虱的取食量逐渐减少,个体间的干扰作用逐渐显现.

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

    DEFF Research Database (Denmark)

    Sohrabi, Fariba; Enkegaard, Annie; Shishehbor, Parviz;

    2013-01-01

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

  13. 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...

  14. Bibliometric Analysis of Research Literature on Bemisia tabaci in the Chinese Journal Full-text Database%重大外来入侵害虫烟粉虱核心期刊研究文献计量分析

    Institute of Scientific and Technical Information of China (English)

    刘新周; 韩群鑫

    2011-01-01

    以《中国期刊全文数据库》作为数据来源,采用文献计量学方法对1990 -2010年烟粉虱研究文献的年份、核心期刊、文献主要产出单位、核心作者群分布情况进行统计分析,在总文献量534篇、第一作者343人中,确定了9位核心作者和8种核心期刊.%The paper took Chinese Journal Full-text Database as the data source, the bibliometric analysis was made on the research literatures of B. Tabaci with bibliometrics method during 1990 - 2010,including the literature number,distribution of publishing years,core authors,research groups and regional distribution. In 534 literatures and 343 first authors, 9 core authors and 8 kinds of core journals were determined.

  15. A SURVEY OF SIZES AND WEIGHTS OF BEMISIA TABACI(HOMOPTERA: ALEYRODIDAE)B BIOTYPE LIFE STAGES FROM FIELD GROWN COTTON AND CANTALOUPES

    Institute of Scientific and Technical Information of China (English)

    Chang-chiChu; JamesS.Buckner; KamilKarut; ThomasP.Freeman; DennisR.Nelson; ThomasJ.Henneberryl

    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 tolate 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 in-creased 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 fe-male and male weights were 39 and 17 μg, respectively. Average widths, lengths, and weights of eggs from cottonand cantaloupe were, 99 μm, 197 μm, and 0.8 μg, respectively. Average widths, lengths, and weights for exu-viae of non-parasitized nymphs from both cotton and cantaloupe were 492 μm, 673 μm, and 1.20 μg, respective-ly; and widths, lengths, and weights of parasitized nymph exuviae were 452 μm, 665 μm, and 3.62 μg, respec-tively. Both exuviae from non-parasitized and parasitized nymphs from cotton leaves were wider, longer, and heavier than those from cantaloupe leaves.

  16. 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.

  17. 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

  18. 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

  19. Q型烟粉虱化学感受蛋白CSP1与植物挥发物的结合特征%Binding Characterization of Chemosensory Protein CSP1 in the Bemisia tabaci Biotype Q with Plant Volatiles

    Institute of Scientific and Technical Information of China (English)

    吴帆; 张晓曼; 赵磊; 崔旭红; 李红亮; 罗晨

    2015-01-01

    α-蒎烯(KD值分别为26.47、39.43、54.01和83.46µmol∙L-1),且3-蒈烯具有较强的竞争结合能力,能在200µmol∙L-1时将1-NPN报告子相对荧光值竞争至约40%。【结论】Q型烟粉虱CSP1蛋白能与测试的多种寄主植物挥发物产生较为广谱的结合能力,尤其与对烟粉虱有趋避性的挥发物的结合更强,表明CSP1很有可能参与Q型烟粉虱对非寄主植物的趋避行为,这对揭示其入侵寄主选择行为生理机制具有重要意义。%[Objective]The objective of this study is to clone the ORF (open reading frame) of chemosensory protein 1 (CSP1) from Bemisia tabaci biotype Q, and characterize the binding profiles of CSP1 with some candidate plants volatiles.[Method] By means of full-length ORF primer, reverse transcription-polymerase chain reaction (RT-PCR) was used to amplify the full-length ORF BtCSP1, which was then cloned into the pET-30a (+)/BL21 (DE3) prokaryotic expression vector after double enzyme digestion. The recombinant BtCSP1 protein was expressed and purified by the method of Ni2+-agroase affinity chromatograph. The protein concentration was measured with Bradford method. The competitive fluorescence assay was used to analyze the binding properties of BtCSP1 with general plant volatiles with different chemical structures. As a suitable fluorescence reporter in studies of insect GOBPs’ function in vivo, N-phenyl-1-naphthylamine (1-NPN) was used to titrate the BtCSP1 solution until the fluorescence emission peak at maximum wavelength of BtCSP1 completely quenched. Then all plant volatiles were added into BtCSP1-1-NPN complex, respectively. The dissociation constants K D data represented the affinity of BtCSP1 with ligands were calculated by the Scatchard equation. [Result] BtCSP1 protein was successfully expressed after induction of 1 mmol·L-1 of IPTG, then purified by Ni2+affinity column with gradient imidazole as washing solutions, finally dialyzed sufficiently using PBS buffer. The working

  20. Comparative analysis of carbohydrates, amino acids and volatile components of honeydew produced by two whiteflies Bemisia tabaci B-biotype and Trialeurodes vaporariorum (Homoptera: Aleyrodidae) feeding cabbage and cucumber%甘蓝与黄瓜寄主上B型烟粉虱和温室白粉虱蜜露糖分、氨基酸和挥发物组分的比较分析

    Institute of Scientific and Technical Information of China (English)

    刘万学; 杨勇; 万方浩; 金道超

    2007-01-01

    粉虱蜜露是粉虱寄生性天敌搜索寄主的主要利它素源.应用离子色谱分别对甘蓝与黄瓜上B型烟粉虱(Bemisia tabaci B_biotype)蜜露以及黄瓜上温室白粉虱Trialeurodes vaporariorum蜜露的接触性利它素糖和氨基酸组分和含量进行了比较研究.结果表明: 2种粉虱在不同寄主植物上的蜜露均富含糖和氨基酸,其中糖含量占绝对优势,甘蓝上B型烟粉虱蜜露、黄瓜上B型烟粉虱蜜露和黄瓜上温室白粉虱蜜露中的糖含量分别是相应氨基酸含量的42.5、2.6和5.4倍,其中糖类物质中又以寡糖含量占绝对优势,分别占89.3%、81.7%和88.2%.不同寄主植物和粉虱种类显著影响蜜露中糖和氨基酸的组成和含量.其中,甘蓝上B型烟粉虱蜜露中的寡糖以二糖占优势,占97.3%;二糖中又以蔗糖异构糖和松二糖占优势,分别占52.7%和35.4%.黄瓜上B型烟粉虱蜜露和温室白粉虱蜜露寡糖中以三糖和四糖占优势,分别占73.1%和85.4%;优势糖水苏(四)糖和松三糖分别占40.3%和 26.2%及49.9%和27.0%.甘蓝上B型烟粉虱蜜露中氨基酸以丙氨酸占优势,含量为66.5%;而黄瓜上B型烟粉虱及温室白粉虱蜜露中氨基酸以甘氨酸含量最高,分别占氨基酸总量的38.2%和51.7%.应用GC-MS对甘蓝上B型烟粉虱蜜露和黄瓜上温室白粉虱蜜露挥发物组分的鉴定结果显示,两种粉虱蜜露中共同含有的主要挥发物为邻苯二甲酸二(2-乙基)己酯.

  1. Comparison of the Activity of the Enzymes Related to Insecticide Resistance in Trialeurodes vaporariorum and Bemisia tabaci%烟粉虱与温室白粉虱羧酸酯酶、谷胱甘肽转移酶和乙酰胆碱酯酶性质的比较研究

    Institute of Scientific and Technical Information of China (English)

    杨秀清; 高希武; 郑炳宗

    2001-01-01

    对温室白粉虱Trialeurodes vaporariorum和烟粉虱Bemisia tabaci羧酸酯酶(CarE )、乙酰胆碱酯酶(AChE)和谷胱甘肽转移酶(GSTs)的生物化学性质进行了初步研究.比较Car E活性,烟粉虱显著高于温室白粉虱,烟粉虱和温室白粉虱CarE对底物乙酸-α-萘酯的Km分别为0.073 mmol/L和3.458 mmol/L.烟粉虱AChE活性分布高峰在2~3 mOD/ (min·头)之间,而温室白粉虱AChE活性分布高峰在10~15 mOD/(min·头)之间,烟粉虱AChE的Km值是温室白粉虱Km值的12.6倍.烟粉虱的GSTs比活力为2 .218 OD/(mg pro·min),显著高于温室白粉虱的GSTs比活力0.663 OD/(mg pro·min) ,差异达极显著水平,烟粉虱GSTs对底物的亲和力比温室白粉虱高.

  2. Response of the zoophytophagous predators Macrolophus pygmaeus and Nesidiocoris tenuis to volatiles of uninfested plants and to plants infested by prey or conspecifics

    NARCIS (Netherlands)

    Lins, J.C.; Loon, van J.J.A.; Bueno, V.H.P.; Lucas-Barbosa, D.; Dicke, M.; Lenteren, van J.C.

    2014-01-01

    Knowledge about the orientation mechanisms used by two important predaceous mirids (Macrolophus pygmaeus Rambour and Nesidiocoris tenuis (Reuter)) in finding their prey (whitefly Bemisia tabaci (Gennadius) and the tomato borer Tuta absoluta (Meyrick)) is limited. In a Y-tube olfactometer, we tested

  3. Comparison of alkaline phosphatase in Bemisia tabaci B-biotype(Homoptera: Aleyrodidae) and Trialeurodes vaporariorum (Homoptera:Aleyrodidae) at different developmental stages%B型烟粉虱与温室白粉虱不同虫态的碱性磷酸酶性质比较

    Institute of Scientific and Technical Information of China (English)

    严盈; 刘万学; 万方浩

    2008-01-01

    为了探明B型烟粉虱,Bemisia tobaci B-biotype和温室白粉虱Trialeurodes vaporariorum体内的碱性磷酸酶(alkaline phosphatase,ALP)在两者竞争替代中所起的作用,以对硝基苯磷酸二钠(pNPP)为底物,采用个体测定和群体测定的方法,研究比较了2种粉虱不同虫态中该酶的性质.结果表明:2种粉虱的碱性磷酸酶比活力在整个发育历期均逐渐增加,成虫期达到最大.温室白粉虱2至4龄若虫(伪蛹)期的碱性磷酸酶比活力分别是B型烟粉虱对应龄期酶比活力的2.58、2.68和3.14倍;B型烟粉虱雌雄成虫的碱性磷酸酶比活力分别是温室白粉虱雌雄成虫酶比活力的1.24和1.26倍,且2种粉虱雌虫的酶比活力显著大于其雄虫.2种粉虱2龄若虫到成虫的碱性磷酸酶最适pH均为7.8,最适温度均为47 ℃;在1龄若虫中均未能检测到该酶活性.测定并比较2种粉虱不同虫态碱性磷酸酶动力学特征参数的结果显示,温室白粉虱碱性磷酸酶在3、4龄若虫的亲和力以及在2,3,4龄若虫的酶蛋白浓度均显著大于B型烟粉虱的对应值,而在成虫期2种粉虱的亲和力、酶蛋白浓度无差异,B型烟粉虱的活化能显著小于温室白粉虱.据此推测,B型烟粉虱利用碱性磷酸酶在若虫期进行组织骨化和生长发育不如温室白粉虱,但羽化为成虫后利用其进行解毒代谢则可能强于温室白粉虱.

  4. Toxicity of various classes of insecticides to Serangium japonicum,a predator of Bemisia tabaci%不同类型杀虫剂对烟粉虱捕食性天敌日本刀角瓢虫的毒力

    Institute of Scientific and Technical Information of China (English)

    赵建伟; 郑宇; 栗丽娜; 何玉仙; 翁启勇

    2012-01-01

    results provide the basis for future guidelines for rational insecticide use, and also help the development of effective 1PM programs involving both natural enemies and insecticides for the control of B. tabaci in China.

  5. Preventie van ontsnappen plaagorganismen: Met een focus op Bemisia tabaci, Spodoptera spp. en Liriomyza spp.

    NARCIS (Netherlands)

    Raaphorst, M.G.M.

    2010-01-01

    Bij het opstellen van eliminatiescenario’s voor quarantaine(-waardige) plagen in kassen is een belangrijke vraag of de luchtramen gesloten moeten blijven tijdens de uitroeiactie, teneinde verspreiding van het plaagorganisme naar andere kassen te voorkomen. Gesloten luchtramen leiden al snel tot een

  6. 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...

  7. 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...

  8. 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 ...

  9. High Ozone (O3) Affects the Fitness Associated with the Microbial Composition and Abundance of Q Biotype Bemisia tabaci

    Science.gov (United States)

    Hong, Yanyun; Yi, Tuyong; Tan, Xiaoling; Zhao, Zihua; Ge, Feng

    2016-01-01

    Ozone (O3) affects the fitness of an insect, such as its development, reproduction and protection against fungal pathogens, but the mechanism by which it does so remains unclear. Here, we compared the fitness (i.e., the growth and development time, reproduction and protection against Beauveria bassiana (B. bassiana) of Q biotype whiteflies fumigated under hO3 (280 ± 20 ppb) and control O3 (50 ± 10 ppb) concentrations. Moreover, we determined that gene expression was related to development, reproduction and immunity to B. bassiana and examined the abundance and composition of bacteria and fungi inside of the body and on the surface of the Q biotype whitefly. We observed a significantly enhanced number of eggs that were laid by a female, shortened developmental time, prolonged adult lifespan, decreased weight of one eclosion, and reduced immunity to B. bassiana in whiteflies under hO3, but hO3 did not significantly affect the expression of genes related to development, reproduction and immunity. However, hO3 obviously changed the composition of the bacterial communities inside of the body and on the surface of the whiteflies, significantly reducing Rickettsia and enhancing Candidatus_Cardinium. Similarly, hO3 significantly enhanced Thysanophora penicillioides from the Trichocomaceae family and reduced Dothideomycetes (at the class level) inside of the body. Furthermore, positive correlations were found between the abundance of Candidatus_Cardinium and the female whitefly ratio and the fecundity of a single female, and positive correlations were found between the abundance of Rickettsia and the weight of adult whiteflies just after eclosion and immunity to B. bassiana. We conclude that hO3 enhances whitefly development and reproduction but impairs immunity to B. bassiana, and our results also suggest that the changes to the microbial environments inside of the body and on the surface could be crucial factors that alter whitefly fitness under hO3.

  10. A comparative study on detection methods for soluble proteins in small insects%小型昆虫蛋白图谱检测方法的比较研究

    Institute of Scientific and Technical Information of China (English)

    褚栋; 张柱亭; 安志兰; 郭笃发; 周洪旭

    2008-01-01

    以烟粉[Bemisia tabaci(Gennadius)]和温室自粉虱[Trialeurodes vaporariorum(Westwood)]小型昆虫为研究对象,比较了这些小型昆虫可溶性蛋白SDS-聚丙烯酰胺凝胶电泳的检测方法.结果表明,改进的复合银染法在蛋白质检测中具有效果好、简单快捷的特点.

  11. Pseudomonas syringae pv. tabaci in papaya seedlings Pseudomonas syringae pv. tabaci em plântulas de mamoeiro

    Directory of Open Access Journals (Sweden)

    Luís Otávio S. Beriam

    2006-03-01

    Full Text Available The natural occurrence of Pseudomonas syringae pv. tabaci causing leaf spot symptoms in papaya seedlings is reported. The pathogen was identified through biochemical, physiological, serological, and molecular assays and artificial inoculations in papaya plants. It was also shown that the strains were pathogenic to bean and tobacco plants. The restriction patterns obtained with Afa I, Alu I, Dde I, Hae III, Hpa II, Hinf I, Sau 3A I and Taq I of the PCR-RFLP of 16S-23S DNAr were identical to the P. s. pv. tabaci patterns. Primers corresponding to hrpL gene of P. syringae were also tested and the results grouped the papaya strains with P s. pv. tabaci. Bacterial strains were deposited at Coleção de Culturas IBSBF, Instituto Biológico, Campinas, Brazil, under access numbers 1687 and 1822.É relatada a ocorrência natural de Pseudomonas syringae pv. tabaci causando sintomas de lesões foliares em plântulas de mamoeiro. O patógeno foi identificado por meio de testes bioquímicos, fisiológicos, serológicos e moleculares, além de ensaios de patogenicidade em plantas de mamoeiro, feijoeiro e fumo. Os padrões de restrição obtidos com as enzimas Afa I, Alu I, Dde I, Hae III, Hpa II, Hinf I, Sal 3A I e Taq I, utilizando-se a técnica de PCR-RLFP da região espaçadora 16S-23S do DNA ribossômico, foram idênticos àqueles apresentados para P. s. pv. tabaci. Primers correspondentes ao gene hrpL de P. syringae foram também testados e os resultados obtidos permitiram agrupar as linhagens isoladas de mamão com P. s. pv. tabaci. Linhagens bacterianas estão depositadas na coleção de culturas IBSBF, Instituto Biológico, Campinas, sob n. 1687 e 1822.

  12. 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...

  13. LIME GREEN LIGHT-EMITTING DIODE EQUIPPED YELLOW STICKY CARD TRAPS FOR MONITORING WHITEFLIES, APHIDS AND FUNGUS GNATS IN GREENHOUSES%应用附加绿黄色光二极管的黄色胶片监测温室中的粉虱、蚜虫和蕈蚊

    Institute of Scientific and Technical Information of China (English)

    朱昌祺; Alvin M. Simmons; 陈天业; Patrick J. Alexander; Thomas J. Henneerry

    2004-01-01

    绿黄色光二极管(LED)附加在塑胶杯和胶片捕捉器可增加捕捉实验室和温室中昆虫的数量.附加有530nm绿黄色LED的塑胶杯捕捉器比没有附加的捕捉到更多的Trialeurodes vaporariorum(Westwood)和Bemisia tabaci(Gennadius)B生态型.在温室中昆虫笼以四季豆和棉花试验,附加有530nm绿黄色LED的黄色胶片(YC)和透明塑胶片(CS)分别缩写为LED-YC和LED-CS)比每一种没有附加的捕捉器捕捉到更多的T. vaporariorum,B.tabaci B生态型,Ahis gossypii(Glover)和Bradysia coprophila(Lintner)成虫.绿黄色LED-YC在温室中有用为监测和控制的潜在性.%Light-emitting diodes (LEDs) were attached to plastic cup and sticky card traps to improve Pest insect catches in the laboratory and in greenhouses. Plastic cup traps equipped with 530 nm lime green LEDs caught more adult Trialeurodes vaporariorum (Westwood) and Bemisia tabaci (Gennadius) biotype B compared with plastic cup traps alone. Yellow sticky card (YC) and clear plastic sticky card (CS) traps equipped with lime green LEDs (LED-YC and LED-CS, respectively) caught more adult T. vaporariorum, B. tabaci biotype B, Aphis gossypii (Glover) and Bradysia coprophila (Lintner) compared with unlit traps of each type in greenhouse cage studies with shell beans, Phaseolus vulgaris (L.) and cotton, Gossypium hirsutum (L.). The lime green LED equipped YC traps have potential for use in greenhouses for insect detection,monitoring, and control.

  14. 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

  15. 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.

  16. Study of drimane sesquiterpenoids from the Persicaria genus and zigiberene from Callitropsis noorkatensis and their effect on the feeding behaviour of Myzus persicae and Bemisia tabaci

    NARCIS (Netherlands)

    Prota, N.

    2015-01-01

    Summary Whitefly is an insect pest that has systematically spread into colder latitudes for the past two decades and it poses a serious threat to crops, mainly due to the viruses for which it acts as a vector. As the applica

  17. Utility of MtCOI polymerase chain reaction-restriction fragment length polymorphism in differentiating between Q and B whitefly Bemisia tabaci biotypes

    Institute of Scientific and Technical Information of China (English)

    Wei-Hua Ma; Xian-Chun Li; Timothy J. Dennehy; Chao-Liang Lei; Mo Wang; Benjamin A. Degain; Robert L. Nichols

    2009-01-01

    The invasive, insecticide-resistant, Q whitefly biotype, has gradually spread to other countries including the US via human-mediated movement of plant materials. We assessed the utility of the VspI-based mtCOl (mitochondrion cytochrome oxidase I) polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) tech-nique as a rapid, cost-effective, and reliable alternative for differentiating the Q from the dominant B biotype in Arizona. Using the standard mtCOI gene sequencing and mtCOI PCR-RFLP techniques, we biotyped eight whitefly strains of five individuals each collected from poinsettia and cotton at different locations in Arizona. Complete concordance was observed between the two methods, with three strains being identified as the Q biotype and five samples as the B biotype. We also scanned the mtCOI gene sequences for VspI polymorphisms in the B and Q biotype whiteflies currently available in the GenBank database. This global screening revealed the existence of three and four VspI polymorphic types for the Q and B biotypes, respectively. Nevertheless, all three VspI polymorphic Q biotype whiteflies shared a common and unique VspI site that can be used to differentiate Q biotype from the four VspI polymorphic B biotype whiteflies identified. These results demonstrate that the VspI-based mtCOI gene PCR-RFLP provides a reliable diagnostic tool for differentiating the Q and B biotype whiteflies in the US and elsewhere.

  18. 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)

  19. Restricted Gene Flow among Lineages of Thrips tabaci Supports Genetic Divergence Among Cryptic Species Groups

    Science.gov (United States)

    Jacobson, Alana L.; Nault, Brian A.; Vargo, Edward L.; Kennedy, George G.

    2016-01-01

    Knowledge of the relative influence of population- versus species-level genetic variation is important to understand patterns of phenotypic variation and ecological relationships that exist among and within morphologically indistinguishable cryptic species and subspecies. In the case of cryptic species groups that are pests, such knowledge is also essential for devising effective population management strategies. The globally important crop pest Thrips tabaci is a taxonomically difficult group of putatively cryptic species. This study examines population genetic structure of T. tabaci and reproductive isolation among lineages of this species complex using microsatellite markers and mitochondrial COI sequences. Overall, genetic structure supports T. tabaci as a cryptic species complex, although limited interbreeding occurs between different clonal groups from the same lineage as well as between individuals from different lineages. These results also provide evidence that thelytoky and arrhenotoky are not fixed phenotypes among members of different T. tabaci lineages that have been generally associated with either reproductive mode. Possible biological and ecological factors contributing to these observations are discussed. PMID:27690317

  20. 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...

  1. 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.

  2. Análise Faunística de Insetos Associados à Cultura do Quiabeiro [Abelmoschus esculentus (L. Moench] em Plantio Comercial, no Município de Canindé de São Francisco, SE, Brasil

    Directory of Open Access Journals (Sweden)

    Daniele Cristina Silva

    2016-08-01

    Abstract. This research aims to study the entomofauna associated with the commercial cultivation of okra in municipality of Canindé do São Francisco, Sergipe State, Brazil, through faunal analysis. The species Bemisia tabaci (Gennadius biotype B, Aphis gossypii (Glover, Phenacoccus sp., Icerya purchasi (Maskell and Lagria villosa (Fabricius were the okra key pests. Diabrotica speciosa (Germar and Gryllus assimilis (Fabricius were plagues of secondary importance. And Leptoglossus zonatus (Dallas, Nezaraviridula L., Pachycoris torridus (Scopoli and Oxycarenus hyalinipennis (Costa were sporadic pests. Four species of predatory insects were found, a constant and dominant (Cycloneda sanguinea L. a dispersed, but constant (Eriopis connexa German and two rare (Hippodamia convergens Guérin-Méneville and Psyllobora confluens F..

  3. Plant-mediated interactions between whiteflies, herbivores, and natural enemies.

    Science.gov (United States)

    Inbar, Moshe; Gerling, Dan

    2008-01-01

    Whiteflies (Homoptera: Aleyrodidae) comprise tiny phloem-sucking insects. The sessile development of their immatures and their phloem-feeding habits (with minimal physical plant damage) often lead to plant-mediated interactions with other organisms. The main data come from the polyphagous pest species Bemisia tabaci (Gennadius) and Trialeurodes vaporariorum (Westwood), which are intricately associated with their host plants. Although these associations might not represent aleyrodids in general, we rely on them to highlight the fundamental role of host plants in numerous ecological interactions between whiteflies, other herbivores, and their natural enemies. Plant traits often affect the activity, preference, and performance of the whiteflies, as well as their entomopathogens, predators, and parasitoids. Leaf structure (primarily pubescence) and constitutive and induced chemical profiles (defensive and nutritional elements) are critically important determinants of whitefly fitness. Pest management-related and evolutionary biology studies could benefit from future research that will consider whiteflies in a multitrophic-level framework.

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

    Science.gov (United States)

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

    2014-01-01

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

  5. 保护地间作芹菜对温室粉虱的防治作用%Control effects of whitefly by intercropping celery in greenhouse

    Institute of Scientific and Technical Information of China (English)

    朱培祥; 刘美昌; 秦玉川; 谢建军; 刘云虹

    2011-01-01

    温室白粉虱Trialeurodes vaporariorum(Westwood)和烟粉虱Bemisia tabaci(Gennadius)是严重危害葫芦科、茄科和豆科等多种蔬菜的主要害虫,具有分布范围广、种群数量大、繁殖力强等特性.作者通过田间试验研究了蔬菜保护地内间作温室粉虱非嗜食植物芹菜(Apium graveliens L.)对其的防治效果.结果表明:与空白处理和常规化学防治相比,在番茄和黄瓜保护地内间作芹菜对温室粉虱均具有显著的防治效果,驱避效果分别达到98.0%和84.5%.这些结果是初步的,但其为进一步研究温室粉虱的寄主选择机制和非化学防治方法提供了依据.%Whitefly ( Trialeurodes vaporariorum (Westood) ) and tobacco whitefly ( Bemisia tabaci ( Gennadius ) ) are major pests of many kinds of vegetables, including the Curcurbitaceae, Solanaceae and Leguminosae. These pests are difficult to control because of their wide host range, large populations and strong reproductive ability. The effect of intercropping host plants of these two whiteflies with celery (Apium graveliens L. ) was studied in a greenhouse.Intercropping with celery effectively controlled whitefly damage to tomatoes and cucumbers; the beneficial effect of celery for these crops reaching about 98.0% and 84. 5% respectively. Although preliminary, these results are important to research on host selection in white-flies, and non-chemical control of the whitefly and tobacco whitefly.

  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. 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

  8. 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

  9. Potencialidade inseticida de extratos aquosos de essências florestais sobre mosca-branca Insecticidal potential of aqueous extracts from arboreous species against whitefly

    Directory of Open Access Journals (Sweden)

    Giani Maria Cavalcante

    2006-01-01

    Full Text Available O objetivo deste trabalho foi avaliar o potencial inseticida de extratos aquosos foliares de quatro essências florestais: algaroba (Prosopis juliflora, aroeira (Myracrodruon urundeuva, leucena (Leucaena leucocephala e sabiá (Mimosa caesalpiniifolia, preparadas em quatro concentrações, 3, 5, 7 e 10%. Foram avaliados três parâmetros em mosca-branca (Bemisia tabaci Gennadius 1889 (Hemiptera: Aleyrodidae: presença de compostos secundários, mortalidade de ovos e ninfas, e alterações na fertilidade do inseto. Determinou-se a presença de tanino nas quatro espécies, e de alcalóides em P. juliflora e M. urundeuva; as saponinas não foram detectadas em nenhuma espécie. Apenas os extratos de P. juliflora e L. leucocephala causaram mortalidade significativa de ovos e ninfas, tendo atingido, em alguns tratamentos, 75% de mortalidade sobre as ninfas. Esses extratos, com o de M. caesalpiniifolia, afetaram a fertilidade do inseto, tendo reduzido a taxa de reprodução, o tempo médio de geração e a taxa intrínseca de crescimento para três gerações de B. tabaci. Os efeitos variam de acordo com a concentração do extrato testado.The objective of this work was to assess the insecticidal potential of aqueous extracts of four arboreous species: mesquite (Prosopis juliflora, "aroeira" (Myracrodruon urundeuva, leucaena (Leucaena leucocephala and "sabiá" (Mimosa caesalpiniifolia, under four concentrations, 3, 5, 7 and 10%. Three parameters were evaluated in Bemisia tabaci (Gennadius 1889 (Hemiptera: Aleyrodidae: the presence of secondary compounds, mortality of eggs and nymphs, and alterations in insect's fertility. The presence of tannin was determined in all species, while alkaloids were observed only in P. juliflora and M. urundeuva; saponins were not detected in any species. Only the exctracts of P. juliflora and L. leucocephala caused significant mortality in eggs and nymphs, reaching, in some treatments, 75% mortality. These extracts and the

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

    Directory of Open Access Journals (Sweden)

    Gustavo G. Gonsebatt

    2012-06-01

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

  11. 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

  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. Whitefly resistance in tomato: from accessions to mechanisms

    NARCIS (Netherlands)

    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 ar

  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. 烟粉虱全基因组DNA四种提取方法的比较%Comparison of Four Methods for Whole Genomic DNA Extraction from Bemisia tabaci

    Institute of Scientific and Technical Information of China (English)

    戴恬美; 吕志创; 万方浩

    2014-01-01

    获得大量、高质量的全基因组DNA是在DNA水平上研究许多生物的分子机制的基本前提。微小昆虫由于其体型微小,单头提取DNA浓度低,无法满足部分试验所需。为寻找一种方便、快捷、高效的全基因组提取方法,参考国内外单头微小昆虫基因组DNA提取常用方法,以烟粉虱为研究材料,选取醋酸钾(KAc)法、盐析法、氯仿-异戊醇法和苯酚提取法四种方法进行多头烟粉虱的全基因组DNA提取。通过微量核酸蛋白分析仪、基因组DNA直接琼脂糖凝胶电泳、甲基化敏感扩增多态性(Methylation sensitive amplification polymorphism,MSAP)引物扩增产物的琼脂糖凝胶电泳对DNA样品进行检测,比较提取DNA的产量、质量,并综合分析各提取方法所需时间及所用试剂的毒性大小。结果表明,盐析法提取的DNA平均浓度为521 ng/μL,纯度能满足分子检测要求,用MSAP引物能得到较好的扩增结果,相比其它方法,盐析法更简便、快速且无毒。因此盐析法是多头烟粉虱全基因组DNA提取的最佳方法。%Obtaining high-quality DNA is a prerequisite to study the molecular mechanisms of many organisms. For tiny insects, low DNA concentration(from one single insect)is unable to meet the need of some experiments. To find a convenient and efficient method for whiteflies genome extraction, KAc, salting-out, chloroform-isoamylol and phenol methods were used to extract bull whiteflies genome DNA, respectively. The efficiency of different DNA extraction methods were evaluated by comparing the concentration, purity, PCR products of DNA, extraction time and the toxicity of the reagents, respectively. The results showed that the average concentration of DNA extraction of salting-out method was 521 ng/μL, and the purity could meet the experiment requirements, and the PCR product brand of MSAP primer amplification was bright. Compared to other methods, salting-out method was more simple, rapid and non-toxic. Therefore, salting-out method was the best ideally method to extract the whole genomic DNA from whiteflies.

  17. 几种药剂对B型烟粉虱的毒力及药效测定%Determination of the toxicity and efficacy of several insecticides to B-type Bemisia tabaci

    Institute of Scientific and Technical Information of China (English)

    孙双艳; 胡敦孝

    2001-01-01

    通过不同药剂分别与苦参碱*内酯混配及药剂中添加323助剂后对B型烟粉虱1~2龄若虫的毒力测定和药效试验,结果表明:各药剂毒力排序为爱福丁>苦参碱.内酯>吡虫啉>天王星>扑虱灵.各药剂加323助剂后均可提高药效,爱福丁、吡虫啉、扑虱灵与苦参碱*内酯混配也可提高药效.生产上轮换用药和药剂合理混配有利于B型烟粉虱的防治和延缓抗药性的产生.

  18. 烟粉虱天敌日本刀角瓢虫的捕食行为%Feeding behavior of Serangium japonicum (Coleoptera: Coccinellidae), a predator of Bemisia tabaci (Homoptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    姚松林; 任顺祥; 黄振

    2005-01-01

    研究了日本刀角瓢虫雌成虫和幼虫捕食粉虱时的各种行为时间分配.结果表明,日本刀角瓢虫成虫的捕食行为可分为爬行、取食、清洁、静息、整翅和排泄6个部分.饥饿后的日本刀角瓢虫幼虫捕食烟粉虱卵时,幼虫各龄期间的取食和爬行时间无显著差异,对烟粉虱卵的处置时间随瓢虫幼虫虫龄的增大而缩短.日本刀角瓢虫雌成虫捕食烟粉虱卵时,饥饿后的雌成虫用于取食的时间显著长于非饥饿的雌成虫,而用于清洁、静息和爬行的时间显著短于非饥饿的雌成虫;饥饿后的瓢虫雌成虫对卵的处置时间显著长于非饥饿的雌成虫.饥饿后的日本刀角瓢虫雌成虫捕食烟粉虱若虫时,瓢虫雌成虫的取食时间随烟粉虱若虫虫龄的增大而增加,清洁和静息时间随烟粉虱若虫虫龄的增大而缩短,对若虫的处置时间随烟粉虱若虫虫龄的增大而增加.

  19. Utility of mtCOI PCR-RFLP in differentiating invasive and local whitefly biotypes of China%mtCOI PCR-RFLP技术鉴别中国入侵型和土著型烟粉虱种群的有效性分析

    Institute of Scientific and Technical Information of China (English)

    周新改; 刘美刚; 杨小红; 林克剑; 马伟华; 王沫

    2012-01-01

    Bemisia tabaci (Gennadius) is one of the most important invasive pests in China. The mtCOI PCR - RFLP technique is currently widely used to identify different whitefly biotypes worldwide. In this paper, we compared the utility and efficiency of five commonly reported mtCOI based PCR - RFLP techniques in differentiating invasive and local B. tabaci biotypes (B, Q, ZHJ1, ZHJ2 and ZHJ3) in China. Our results show that the Alul enzyme fails to differentiate between the B and ZHJ2 biotypes, the TaqI enzyme cannot effectively differentiate between the ZHJ3 and Q biotypes, the Vspl enzyme is not effective in differentiating between either the B and ZHJ2 biotypes or the Q and ZHJ1 biotypes, and the Msel and Tru9I enzymes are completely unable to identify any of the five biotypes found in China.%烟粉虱Bemisia tabaci( Gennadius)是世界范围内最重要的入侵生物之一,准确地鉴别烟粉虱入侵生物型和土著生物型具有十分重要的现实意义.mtCOI PCR-RFLP技术具有快速、高效的特点,是当前应用最广泛的烟粉虱生物型鉴定技术,但是,不同限制性内切酶为基础的mtCOI PCR-RFLP技术在鉴定我国烟粉虱种群中的有效性仍不明了.本文比较了已报导的5种mtCOI PCR-RFLP技术在鉴别中国烟粉虱种群入侵生物型和土著生物型(B型、Q型,ZHJ1型、ZHJ2型、ZHJ3型)的有效性.结果表明,内切酶AluI不能区分B型和ZHJ2型烟粉虱;内切酶TaqI不能准确区分ZHJ3型和Q型烟粉虱个体;而内切酶VspI不仅不能准确区分ZHJ1型和Q型烟粉虱个体,也不能准确区分B型和ZHJ2型烟粉虱;内切酶MseI和Tru9I则不能有效鉴别上述5种烟粉虱生物型,因此不适宜推广使用.

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

    Science.gov (United States)

    Ghanim, Murad; Brumin, Marina; Popovski, Smadar

    2009-08-01

    A simple, rapid, inexpensive method for the localization of virus transcripts in plant and insect vector tissues is reported here. The method based on fluorescent in situ hybridization using short DNA oligonucleotides complementary to an RNA segment representing a virus transcript in the infected plant or insect vector. The DNA probe harbors a fluorescent molecule at its 5' or 3' ends. The protocol: simple fixation, hybridization, minimal washing and confocal microscopy, provides a highly specific signal. The reliability of the protocol was tested by localizing two phloem-limited plant virus transcripts in infected plants and insect tissues: Tomato yellow leaf curl virus (TYLCV) (Begomovirus: Geminiviridae), exclusively transmitted by the whitefly Bemisia tabaci (Gennadius) in a circulative non-propagative manner, and Potato leafroll virus (Polerovirus: Luteoviridae), similarly transmitted by the aphid Myzus persicae (Sulzer). Transcripts for both viruses were localized specifically to the phloem sieve elements of infected plants, while negative controls showed no signal. TYLCV transcripts were also localized to the digestive tract of B. tabaci, confirming TYLCV route of transmission. Compared to previous methods for localizing virus transcripts in plant and insect tissues that include complex steps for in-vitro probe preparation or antibody raising, tissue fixation, block preparation, sectioning and hybridization, the method described below provides very reliable, convincing, background-free results with much less time, effort and cost. PMID:19406154

  1. 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

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

    Science.gov (United States)

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

    2013-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Gustavo G. GONSEBATT

    2012-01-01

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

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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

  7. 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.

  8. Sequential sampling of Bemisia tuberculata (Bondar, 1923 (Hemiptera: Aleyrodidae on cassava crop

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    ANTONIO S. SILVA

    2014-06-01

    Full Text Available Estimate efficiently of the whitefly population (Bemisia tuberculata Bondar in cassava, to assist in decision making of pest control is one of the advantages of sequential sampling plans. Therefore, the objective of this study was to determine a sequential sampling plan according to two methods of pest management, using biological and/or chemical control. Samples were obtained in a commercial field of 2.500,00 m2, divided into 100 plots. The visualization method was used for sampling of the upper leaves by counting the number of adults. In total 15 samples were taken weekly from January to April 2012. The spatial distribution model which best fit to the behavior of B. tuberculata adults was the negative binomial distribution. Levels adapted for biological and chemical control were five and twenty adults per plant, respectively. Sampling plans resulted in two decisions for each proposed method. Thus, for population control the upper limit was defined as S1 = 4.2056 + 2.1540n (biological and S1 = 20.219 + 10.4306n (chemical; and the lower limit where the pest control is not recommended was defined by S0 = -4.2056 + 2.1540n (biological and S0 = -20.219 + 10.4306n (chemical. Sequential sampling estimated the maximum number of sample units necessary for decision-making of three samples with 1.34 adults for biological control and 3.85 sample units with 7.39 adult pests for chemical control.

  9. 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

  10. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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

  13. 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.

  14. An improved bioassay method for adults of whiteflies%一种改进的粉虱成虫生物测定方法

    Institute of Scientific and Technical Information of China (English)

    田玉安; 杨茜茹; 梁沛; 高希武

    2012-01-01

    Bioassay is a very important technique for insecticide resistance detection. An improved bioassay method for adults of Bemisia tabaci ( Gennadius) and Trialeurodes vaporariorum ( Westwood) was reported in present paper. This method primarily composed of a cylinder tube, made from a centrifuge tube (38 mm in diameter and 107 mm in length) with bottom cut off and replaced with a piece of black cotton cloth to do the test. The nitenpyram treated eggplant - leaf disc, which was proved here to be a good material for the bioassay of adult whiteflies, was laid abaxial side down on a bed of agar gel inside the lid of the tube. The improved bioassay method described here offered a dependable, accurate, and relatively simple means to explore dose - response relationships in evaluating susceptibility of adult whiteflies to different varieties of insecticides.%生物测定是检测害虫抗药性的一项重要技术.利用100 mL插口圆底聚丙烯离心管对现在应用较多的粉虱成虫生物测定方法——琼脂保湿浸叶法进行了改进.改进后的方法不影响粉虱成虫的持续取食,具有操作简单、结果重复性好及无需对成虫麻醉等优点.同时发现茄子叶片对于B型烟粉虱Bemisia tabaci (Gennadius)Bbiotype和温室白粉虱Trialeurodes vaporariorum( Westwood)成虫均是一种非常适合的生测材料.利用该方法分3次独立测定了烯啶虫胺对B型烟粉虱和温室白粉虱混合日龄成虫的毒力,结果具有很好的重复性.

  15. Laboratory evaluation of products to reduce settling of sweetpotato whitefly adults.

    Science.gov (United States)

    Schuster, D J; Thompson, S; Ortega, L D; Polston, J E

    2009-08-01

    The impact of trademarked and commercial products on settling of adults of the sweetpotato whitefly, Bemisia tabaci (Gennadius), was studied in the laboratory. A no-choice bioassay using leaf disks of tomato, Solanum esculentum L., was developed to evaluate the impact of concentration series of products on settling of B. tabaci adults. The concentration of each product that would reduce settling by 50% (SC50) was estimated for each product using standard probit analyses, and the values were compared with that of Ultra-Fine Oil, a paraffinic oil product that is known to reduce settling of whitefly adults. Twenty-two trademarked products and 42 other products were evaluated in the laboratory bioassay. Based upon comparisons of fiducial limits of the respective SC50 values, Dawn detergent and E-RASE jojoba oil were the only trademarked products that were as effective as Ultra-Fine Oil in reducing settling of B. tabaci adults. Of the nontrademarked products, 25 were similar to Ultra-Fine Oil, although cedar, geranium, ginger, Hamlin (citrus), patchouli, olive and wintergreen oils, as well as citronellal and limonene, had ratios of respective SC50 values with that of Ultra-Fine Oil of approximately 1.5 or less. Combinations of limonene and citronellal with either olive oil or Ultra-Fine Oil were 15 and 30 times, respectively, more effective than Ultra-Fine Oil alone. Candidate products and combinations of products were further evaluated on tomato seedlings in no-choice screenhouse trials for effects on oviposition and on transmission of Tomato yellow leaf curl virus (family Geminiviridae, genus Begomovirus, TYLCV) by B. tabaci. Ultra-Fine Oil and olive oil reduced oviposition and transmission of TYLCV in the screenhouse trials. Ginger oil and limonene reduced oviposition in at least one screenhouse trial but did reduce transmission of TYLCV. The laboratory bioassay provided a rapid and relatively easy method to compare products for reducing settling of B. tabaci adults

  16. Susceptibility of ornamental pepper banker plant candidates to common greenhouse pests

    Science.gov (United States)

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

  17. 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

  18. 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...

  19. Influence of cover crop and intercrop systems on Bemisia argentifolli (Hemiptera: Aleyrodidae) infestation and associated squash silverleaf disorder in zucchini.

    Science.gov (United States)

    Manandhar, Roshan; Hooks, Cerruti R R; Wright, Mark G

    2009-04-01

    Field experiments were conducted to evaluate the effects of cover cropping and intercropping on population densities of silverleaf whitefly, Bemisia argentifolli Bellow and Perring, and the incidence of squash silverleaf disorder (SSL) in zucchini, Cucurbita pepo L., in Oahu, HI. Two cover crops, buckwheat (BW), Fagopyrum esculentum Moench, and white clover (WC), Trifolium repens L., or sunn hemp (SH), Crotolaria juncea L., and an intercropped vegetable, okra, Abelmonchus esculentus L., were evaluated during the 2003, 2005, and 2006 growing seasons, respectively. Population densities of whiteflies and SSL severity varied during the three field experiments. In 2003, the severity of SSL and percentage of leaves displaying symptoms were significantly lower on zucchini plants in WC than BW plots throughout the crops' growth cycle. Additionally, the percentage of leaves per plant displaying SSL symptoms was significantly greater in bare-ground (BG) compared with the pooled BW and WC treatments on each inspection date. In 2005, zucchini intercropped with okra had lower numbers of adult whiteflies and resulted in significantly lower severity of SSL than pooled BW and WC treatments. During 2006, zucchini grown with SH had significantly lower numbers of all whitefly stages (i.e., egg, immature, and adult) and less SSL severity symptoms than BW. Despite these differences in whitefly numbers and SSL severity, marketable yields were not significantly lower in BW compared with WC or SH treatment plots during the study. The mechanisms underlying these results and the feasibility of using cover crops and intercrops to manage B. argentifolli and SSL are discussed.

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

    Science.gov (United States)

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

    2010-01-01

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

  2. Using magnesium oxide-glass slide method to estimate survival amount of whitefly nymphs%估计粉虱若虫存活数量的新方法——氧化镁薄板法

    Institute of Scientific and Technical Information of China (English)

    王海鸿; 黄东东; 问锦曾; 雷仲仁

    2009-01-01

    介绍一种估计粉虱若虫存活数的简易方法.粉虱若虫分泌的蜜露滴落在氧化镁薄板上后形成清晰的圆坑,在体视显微镜下易于观察和计数,在确定粉虱若虫数量(Nd)和平均蜜露数(Nn)存在线性相关后,相应得出若虫数量评估因子(NEF)=Nn/Nd,提出通过蜜露数和若虫数量评估因子估算若虫数量的方法.在蕃茄叶片上,烟粉虱Bemisia tabaci(Gennadius)1~2龄若虫、3~4龄若虫和温室白粉虱Trialeurodes vaporariorum(Westwoed)1~2龄若虫、3~4龄若虫的数量评估因子NEF分别为7.73,5.69,5.18和5.03.应用该方法检测吡虫啉对粉虱的毒力,并与传统方法进行比较,两者没有显著差异,而且该方法更简便准确.

  3. 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.

  4. 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.

  5. 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.

  6. Functional analysis of the aefR mutation and identification of its binding site in Pseudomonas syringae pv. tabaci 11528.

    Science.gov (United States)

    Yun, Sora; Lee, Jun Seung; Do, Mi Sol; Jeon, Young Ji; Cha, Ji Young; Baik, Hyung Suk

    2015-11-01

    The TetR family transcriptional regulator AefR contributes to the regulation of the quorum-sensing system. However, the role of AefR in the regulatory network of the phytopathogen Pseudomonas syringae pathovars is not known. In this study, the phenotype of a P. syringae pv. tabaci 11528 aefR deletion mutant strain was examined. The aefR gene expression and AefR DNA-binding affinity were examined by quantitative real-time polymerase chain reaction and electrophoretic mobility shift assay, respectively. AefR was found to control quorum-sensing genes as well as the efflux genes mexE, mexF, and oprN via an indirect mechanism. AefR binds to its own operator site as well as to the palindromic sequence between positions -28 and -2 corresponding to the transcription start site of aefR, as determined by dye primer sequencing. These results suggest that P. syringae AefR modulates quorum sensing and efflux as well as its own expression, which can be exploited by strategies developed to manage this plant parasite. PMID:26376742

  7. 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)

  8. 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.

  9. 基于SCAR标记技术的丽蚜小蜂快速识别%SCAR marker for rapid identification of Encarsia formosa Gahan (Hymenoptera: Aphelinidae)

    Institute of Scientific and Technical Information of China (English)

    张锐锐; 张桂芬; 贤振华; 万方浩

    2012-01-01

    丽蚜小蜂Encarsia formosa Gahan作为温室粉虱Trialeurodes vaporariorum Westwood和烟粉虱Bemisia tabaci (Gennadius)等粉虱类害虫的优势寄生蜂而备受关注.针对丽蚜小蜂体型微小,难以与其他同域近缘种寄生蜂快速、准确区别的问题,本研究采用SCAR(sequence characterized amplified region,特异性扩增区域)标记技术,筛选出一对丽蚜小蜂特征片段扩增引物(EFZZF/EFZZR),其扩增片段的大小为287 bp.种特异性检验结果表明,该对引物只对丽蚜小蜂的基因组DNA具有扩增能力,对其近缘种属寄生蜂如浅黄恩蚜小蜂Encarsia sophia(Girault & Dodd)、海氏桨角蚜小蜂Eretmocerus hayati Zolnerowich & Rose、本地未知种桨角蚜小蜂Eretmocerus sp.、蒙氏桨角蚜小蜂Eretmocerus mundus Mercet、刺粉虱黑蜂Amitus hesperidum Silvertri不具有扩增效果,对丽蚜小蜂的寄主包括不同生物型(B型、Q型、ZHJ-1型和ZHJ-2型)的烟粉虱、温室粉虱以及我国最常见的黑刺粉虱Aleurocanthus spiniferus (Quaintanca)等亦不具有扩增能力.同时,该检测技术灵敏度高,对成虫的最低检出阈值为7.812 ng/μL(相当于1/1 600头成虫).研究结果对丽蚜小蜂的种类识别、寄主谱的确定及其有效利用具有重要意义.%Encarsia formosa Gahan ( Hymenoptera: Aphelinidae) is the dominant parasitoid of important whitefly species, such as Trialeurodes vaporariorum Westwood and Bemisia tabaci (Gennadius). Most of the Aphelinidae species are small and morphologically similar, and this makes them hard to be identified accurately. In this study, a pair of SCAR (sequence characterized amplified region) primers (EFZZF/ EFZZR) which are specific to En. formosa was developed by using other five common Aphelinidae species and four biotypes of B. tabaci as the control. The fragment amplified by these primer pairs was 287 bp in length. Species specificity test showed that all En. formosa specimens were detected with no cross

  10. 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

  11. Evaluations of melon germplasm reported to exhibit host plant resistance to sweetpotato whitefly

    Science.gov (United States)

    Sweetpotato whitefly (MEAM1 cryptic species of Bemisia tabaci; SPWF) displaced B. tabaci biotype A in 1991 in the lower desert area of southern California and the adjoining areas of Arizona and western Mexico. The search for high-level host plant resistance to this devastating insect has been ongoin...

  12. 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

    Experiments were carried out to investigate whether Potato spindle tuber viroid (PSTVd) can be transmitted intra- and inter-species from infected Solanum jasminoides to non-infected S. jasminoides and S. esculentum and from infected Brugmansia sp. to S. esculentum by Frankliniella occidentalis...... and Thrips tabaci by leaf sucking. The F. occidentalis experiments also included feeding on pollen prior to feeding on PSTVd-infected leaf. No thrips-mediated transmission of PSTVd was recorded. The possibility of PSTVd transmission by Apis mellifera and Bombus terrestris during their feeding...

  13. Biology of Bemisia tuberculata Bondar (Aleyrodidae) and parasitism by Encarsia porteri (Mercet, 1928) (Hymenoptera, Aphelinidae) on cassava plants.

    Science.gov (United States)

    Andrade Filho, N N; Roel, A R; Penteado-Dias, A M; Costa, R B

    2012-11-01

    The whitefly Bemisia tuberculata has caused serious damage to cassava producing areas in the state of Mato Grosso do Sul. However, little is known about the biological characteristics of this species. The objective of this study was therefore, to monitor the development of this species bred on cassava plants under controlled greenhouse conditions, and to determine its most vulnerable stages and its reproductive capacity, as well as measuring the length and width each stage of development. To obtain these data, adult individuals were kept in voile traps on cassava leaves of five different plants, totalling ten leaves. After 24 hours the leaves were removed from the traps thus making each egg-laden leaf an experimental unit. The lowest mortality rate was record in the last nymphal stage ('pupae) compared with the other development stages. The highest mortality occurred in the nymphs at the 2nd and 3rd instars. Each female laid an average of 6.3 eggs in 24 hours. Thirteen days after egg laying, every one of the nymphs was fixed on the leaves of cassava plants. From the egg laying stage up until the adult stage, the process took 26 days. The proportion of females was 73.5%. The average size of the B. tuberculata egg was 163.22 µm in length and 72.39 µm in width and the "pupae" is 915.82 µm in length and 628.71 µm in width. The measurements of males were 797.16 µm in length and 200.81 µm in width and the length females 916.12 µm in length and 338.99 µm in width. The parasitoid Encarsia porteri (Mercet, 1928) (Hymenoptera, Aphelinidae) was found in the insect stock culture.

  14. 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

  15. 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

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

    Directory of Open Access Journals (Sweden)

    Stella Mutisya

    2016-09-01

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

  17. Trophic relationships between predators, whiteflies and their parasitoids in tomato greenhouses: a molecular approach.

    Science.gov (United States)

    Moreno-Ripoll, R; Gabarra, R; Symondson, W O C; King, R A; Agustí, N

    2012-08-01

    The whiteflies Bemisia tabaci Gennadius and Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) are two of the main pests in tomato crops. Their biological control in Mediterranean IPM systems is based on the predators Macrolophus pygmaeus (Rambur) and Nesidiocoris tenuis Reuter (Hemiptera: Miridae), as well as on the parasitoids Eretmocerus mundus (Mercet) and Encarsia pergandiella Howard (Hymenoptera: Aphelinidae). These natural enemies may interact with each other and their joint use could interfere with the biological control of those whitefly pests. Analysis of predator-prey interactions under field conditions is therefore essential in order to optimize whitefly control. Species-specific polymerase chain reaction (PCR)-primers were designed to detect DNA fragments of these whiteflies and parasitoids within both predator species in tomato greenhouses. We demonstrated that both predators feed on both whitefly species, as well as on both parasitoids under greenhouse conditions. Prey molecular detection was possible where prey abundance was very low or even where predation was not observed under a microscope. Whitefly DNA detection was positively correlated with adult whitefly abundance in the crop. However, a significant relationship was not observed between parasitoid DNA detection and the abundance of parasitoid pupae, even though the predation rate on parasitoids was high. This unidirectional intraguild predation (predators on parasitoids) could potentially reduce their combined impact on their joint prey/host. Prey molecular detection provided improved detection of prey consumption in greenhouse crops, as well as the possibility to identify which prey species were consumed by each predator species present in the greenhouse, offering a blueprint with wider applicability to other food webs.

  18. 警惕烟粉虱大暴发导致新的蔬菜病毒病流行

    Institute of Scientific and Technical Information of China (English)

    冯兰香; 杨宇红; 谢丙炎; 杨翠荣

    2001-01-01

    @@1976年的7、8月份,北京地区首次暴发了温室白粉虱(Trialeurodes vaporariorum Wes twood),温室、大棚蔬菜上粉虱密布,菜区上空粉虱飞舞,就连家庭花卉也深受其害。20多年过去了,昔日的景象今日又重现。2000年8月29日和9月18日人民日报(网络版)相继发表了题为"白粉虱成虫肆虐廊坊任丘规模之大实属历史罕见"和"天津:空中飘着'白粉虱'"两篇文章。但是,这次大发生的小白蛾子并不是以前的温室白粉虱,而是适应性更强、寄主范围更广、危害性更大的烟粉虱(Bemisia tabaci Gennadius)。虽然这两种粉虱外形相似,也都是白色,但是仔细观查可知烟粉虱成虫比温室白粉虱成虫略小,翅形略平铺;在扩大镜下检查,两者在卵柄,蛹壳上的前缘毛、尾气管孔口的特征方面均有差异。然而,它们在生物学上的差异更为显著。

  19. 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.

  20. 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

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

    Science.gov (United States)

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

    2016-08-01

    Since 2003, growers of Florida watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] have periodically suffered large losses from a disease caused by Squash vein yellowing virus (SqVYV), which is transmitted by the whitefly Middle East-Asia Minor 1 (MEAM1), formerly Bemisia tabaci (Gennadius) biotype B. Common cucurbit weeds like balsam apple (Momordica charantia L.) and smellmelon [Cucumis melo var. dudaim (L.) Naud.] are natural hosts of SqVYV, and creeping cucumber (Melothria pendula L.) is an experimental host. Study objectives were to compare these weeds and 'Mickylee' watermelon as sources of inoculum for SqVYV via MEAM1 transmission, to determine weed susceptibility to SqVYV, and to evaluate whitefly settling and oviposition behaviors on infected vs. mock-inoculated (inoculated with buffer only) creeping cucumber leaves. We found that the lowest percentage of watermelon recipient plants was infected when balsam apple was used as a source of inoculum. Watermelon was more susceptible to infection than balsam apple or smellmelon. However, all weed species were equally susceptible to SqVYV when inoculated by whitefly. For the first 5 h after release, whiteflies had no preference to settle on infected vs. mock-inoculated creeping cucumber leaves. After 24 h, whiteflies preferred to settle on mock-inoculated leaves, and more eggs were laid on mock-inoculated creeping cucumber leaves than on SqVYV-infected leaves. The transmission experiments (source of inoculum and susceptibility) show these weed species as potential inoculum sources of the virus. The changing settling preference of whiteflies from infected to mock-inoculated plants could lead to rapid spread of virus in the agroecosystem. PMID:27400705

  2. 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,...

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

    Science.gov (United States)

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

  4. First Report of Tomato yellow leaf curl virus in Tomato in the Netherlands

    NARCIS (Netherlands)

    Botermans, M.; Verhoeven, J.Th.J.; Jansen, C.C.C.; Roenhorst, J.W.; Stijger, C.C.M.M.; Pham, K.T.K.

    2009-01-01

    Tomato yellow leaf curl virus (TYLCV) is an economically important virus with tomato (Solanum lycopersicum L.) as its main host. The virus is widely distributed in subtropical areas and is transmitted by the tobacco whitefly (Bemisia tabaci) in a persistent manner. TYLCV has a quarantine status (IIA

  5. Host plant resistance in melon to sweetpotato whitefly in California and Arizona

    Science.gov (United States)

    Sweetpotato whitefly biotype B (MEAM1 cryptic species of Bemisia tabaci; SPWF) feeding severely impacts fall season melon (Cucumis melo L.) yield and quality in the lower deserts of California and Arizona. Melon accessions PI 313970 and TGR 1551 (PI 482420) have been reported to exhibit host plant r...

  6. Q96 昆虫学

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    褐飞虱对噻嗪酮抗性的遗传分析=Genetic analysis of resistance to buprofezin in the brown planthopper, Nilaparvata lugens (Stal) (Homoptera: Delphacidae);B型烟粉虱抗噻虫嗪品系的遗传分化=Genetic differentiation in the thiamethoxam-resistant strain ofBemisia tabaci B-biotype。

  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. Analysis of Molecular Polymorphism of Pseudomonas syringae pv. tabaci in Jilin Province%吉林省烟草野火病菌群体分子多态性分析∗

    Institute of Scientific and Technical Information of China (English)

    夏纬跃; 卢宝慧; 杨丽娜; 南楠; 刘燕妮; 陈长卿; 高洁

    2014-01-01

    为研究烟草野火病菌的群体遗传多样性,采用正交试验方法,对5个多态性引物( REP,ERIC,BOX, J3,IS1112)的Rep-PCR反应体系分别进行了优化,同时优化了体系中的Mg2+、dNTP、rTaq 酶等几个因素,并在此基础上对来源于吉林省不同地区的70株烟草野火病菌进行了分子多态性分析。结果表明:优化的PCR反应体系电泳图谱清晰,多态性丰富,重复性好,适合烟草野火病菌群体分子标记研究。通过聚类分析发现,吉林省烟草野火病菌群体存在分子多态性,在遗传相似系数为0�9时,70个菌株被聚为4个类群( G1~G4),其中G1类群最大(39个菌株,占55�71%),而G3类群最小,仅包括2个菌株。 G1和G2类群分别包含了5个和3个亚群。不同类群和亚群的菌株地理来源存在多样性。%To study the population genetic diversity of Pseudomonas syringae pv. tabaci, the orthogo⁃nal design of L9(34)was used to optimize PCR reaction system factors including Mg2+,dNTP,rTaq DNA polymerase and primers of five polymorphic primers(REP,ERIC,BOX,J3 and IS1112). Mo⁃lecular polymorphism of 70 strains isolated from different areas in Jilin province was analyzed using the optimized Rep-PCR system. The results showed clear electrophoresis, high polymorphism and stable repeatability with the optimized Rep-PCR system which was suitable for study of molecular polymorphism of P. syringae pv. tabaci. The clustering results revealed that molecular polymorphism existed in the population of P. syringae pv. tabaci from Jilin province. The tested 70 strains were clustered into four groups ( G1—G4) with 0�9 of genetic similarity coefficient, in which G1 group was the most ( 39 strains,55�71%) , while G3 group was the least ( only 2 strains) . The groups G1 and G2 were separated into five and three subgroups, respectively. For geographical origin of strains in different groups and subgroups

  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. 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

  12. 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...

  13. Entomopathogenic Potential of Verticillium and Acremonium Species (Deuteromycotina: Hyphomycetes)

    DEFF Research Database (Denmark)

    Steenberg, Tove; Humber, Richard A

    1999-01-01

    entomopathogen. The fungi were identified as Verticillium fusisporum, Veritcillium psalliotae, Verticillium lamellicola, and species of Acremonium. Isolates of these fungi were bioassayed against the sweet-potato whitefly (Bemisia tabaci) and against the housefly (Musca domestica) to examine....... In general, V. lecanii was the most pathogenic species. Immature whiteflies appeared to be more susceptible to fungal infection than adult houseflies, and the host range for several of the fungi also included lesser mealworm....

  14. 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...

  15. 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...

  16. Epidémiologie, diversité génétique et phylogéographie des virus de la mosaïque africaine du manioc dans la région de Yangambi en République Démocratique du Congo

    OpenAIRE

    Monde Te Kazangba, Godefroid

    2010-01-01

    Molecular epidemiology on genetic diversity and ecophylogeography of cassava mosaic disease (CMD) viruses focused on genes AC2 & AC4 was conducted in Yangambi in Democratic Republic of Congo (DRCongo). Cassava leaves, Fabaceae and whiteflies (Bemisia tabaci) were collected and analyzed by PCR and ELISA. The molecular data were plotted on a Yangambi map published by Geomatics Unity, UCL. CMD viruses ecophylogeographical study has considered the different agroecosystems in relation to cassava c...

  17. 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...

  18. 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.

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

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    Haipeng Zhao

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

  20. 烟草野火病菌对细菌杀星的敏感性测定及敏感基线建立%Sensitivity Determination and Sensitivity Baseline Establishment of Pseudomonas syringae pv.tabaci to Streptomycin·Saikuzuo

    Institute of Scientific and Technical Information of China (English)

    陈长卿; 隋原; 杨丽娜; 周洪波; 张文中; 高洁

    2011-01-01

    从黑龙江省和吉林省烟草主要种植区获得烟草野火病菌(Pseudomonas syringae pv.tabaci)菌株61个,采用抑菌圈法对50%细菌杀星WP进行了敏感性测定.结果表明:不同地理来源的烟草野火病菌对细菌杀星敏感性有一定差异,EC50=1.070~1.517 μg/mL,平均1.421μg/mL;黑龙江省鸡西的菌株h28为最敏感菌株,其EC50为1.070μg/mL,而黑龙江宁安菌株h40敏感性最低,其EC50值为1.517 μg/mL.同时确定了两省烟草野火病菌对细菌沙星的敏感基线为1.421μg/mL,可用于对烟草野火病菌对细菌杀星的抗药性监测;烟草野火病菌对细菌杀星未产生抗药性.%The fungicide sensitivity to streptomycin · saikuzuo of sixty one strains of Pseudomonas syringae pv. Tabaci (Pst) from tabacco regions in Heilongjiang and Jilin provinces was determined using the method of inhibition zone. The results showed there were sensitivity differences among the strains, and EC50 value of all strains was lower than 2 μg/mL, which ranged from 1.070 to 1.517 μg/mL, and the av erage value was 1.421 μg/mL. Strains h28( EC50 1.070 μg/mL) from Jixi, Heilongjiang was the most sensitive to the fungicide, but h4O(EC50 1.517 μg/mL) from Ning'an, Heilongjiang was strain of the low est sensitivity. The sensitivity baseline of Pst strains to streptomycin ? saikuzuo was determined as 1.421 μg/mL, which could be used for monitoring resistance of Pst strains to the fungicide. There wasno resistance of Pst strains to the fungicide.

  1. 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

  2. Chinese squash leaf curl virus: a new whitefly-transmitted geminivirus

    Institute of Scientific and Technical Information of China (English)

    洪益国; 王小凤; 田波; 蔡健和

    1995-01-01

    Coat protein (CP) gene of the Chinese squash !eaf curl virus (SqLCV-C) was amplified through PC’R, cloned and completely sequenced. Based on the comparisons at the levels of both CP gene nucleotide and CP -deduced amino acid sequences with other geminiviruses, SqLCV-C is confirmed to be distinct from the American squash leaf curl virus (SqLCV-E). It is a new geminivirus transmitted by whitefly Bemisia tabaci, which infects dicotyledonous plants and is more closely related to the Indian cassava mosaic virus (ICMV).

  3. Study on Biological Characteristics and Population Dynamics of Whitefly (Bemisia tabaci) in Growing Vegetables in the Suburbs%外来入侵烟粉虱生物特性及其种群数量变动规律研究

    Institute of Scientific and Technical Information of China (English)

    李达林; 汪恩国; 林凌伟

    2012-01-01

    In order to explore population dynamics of whitefly (Bemisia tabaci) in growing vegetables in the suburbs, and improve monitoring and control techniques, adult whitefly (Bemisia tabaci) were reared and trapped with oil painting yellow plastic plates during 2005-2010. It showed that annual population dynamics of whitefly might be described by bimodal curve, the summer peak usually appeared during mid-May and early September, and the autumn peak usually came between mid-October and late November. The adults could live in greenhouse for one year and had an overwintering rate of 20% in the open. Between the year to year movement of whitefly could be described by bimodal curve and the curve model was M o. = 312.21N 2 -6187.1N + 30787 ( n=5 , r=0.9834 ** ) and M g. = 564.7 N 2 -10506N + 49013 ( n=5 , r=0.9967 ** ) . There were four main factors affecting whitefly population, i.e., base population, climate, farming system and flood inundation, and the most important factor was temperature. The whitefly population density ( M ) was changed with temperature ( T ), the linear relationship could be described by the model M=0.607T-4.0645, n=36; r=0.6826 ** , and the curve model was M = 0.0071T 2 +0.3513T-2.2188, n=36; r=0.6846 ** . When 10 days ’ average temperature was between 8-10℃ , the whitefly population was in survival critical situation. The population density was the small at the 10 days ’ average temperature of 10-20℃. When 10 days ’ average temperature was above 20℃, the population increased very fast with the increasing of temperature. However, the whitefly population decreased to a comparative bust at the 10 days ’ average temperature of above 30℃. Afterwards, the population increased to the peak again, and caused the heavy damage of autumn vegetable production.%为了揭示外来入侵烟粉虱种群数量季节性消长和年度间变动规律,提高监测与防控水平,2005—2010年通过饲养观

  4. 四种粉虱种群超微形态特征多样性研究%Studies on the ultra-morphological characteristics diversity of four populations of whitefly species ( Hemiptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    孙会忠; 董钧锋; 宋月芹; 林克剑

    2011-01-01

    运用扫描电子显微镜对烟粉虱Bemisia tabaci、非洲伯粉虱Bemisia afer、温室粉虱Trialeurodes vaporariorum和柑桔粉虱Dialeurodes cirri 4种粉虱4龄若虫的超微形态特征进行了初步研究.结果表明,扫描电子显微镜下的超微结构特征可很好地将4种粉虱区分开来,如烟粉虱圆锥状的舌状突,非洲伯粉虱尾沟两侧隆起上形成的横脊,温室粉虱形态典型的乳突和泌蜡孔,柑桔粉虱近圆形的皿状孔及其尾沟内的卵石状乳突等特异特征.并根据种间的超微结构特异特征,编制了不同种的简明检索表.超微形态特征为粉虱种群鉴定提供了可靠的理论参考.%The ultra-morphological characteristics of the 4th instar nymphs of four whitefly species, including Bemisia tabaci,Bemisia afer, Trialeurodes vaporariorum and Dialeurodes citri, was observed with scanning electron microscope (SEM). The results showed that the ultra-morphological characteristics could be make a distinction among four whitefly species researched,such as the conical lingula of Bemisia tabaci,the horizontal wrinkles on bulge region beside the end groove of Bemisia afer, the protuberance and aperture uesd to screte wax of Trialeurodes vaporariorum, the circular vasiform orifice and pebble protrude in the end groove of Dialeurodes cirri,et al. And on the basis of the peculiar ultramorphological characteristics among species of whitefly researched, draw up a concise program to retrieval. The ultramorphological characteristics provided dependable reference to taxonomy for whitefly.

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

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    Thiago Luis Martins Fanela

    2012-12-01

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

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

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    Maria Elisa de Sena Fernandes

    2009-11-01

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

  7. 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.

  8. Ecdysteroids and juvenile hormones of whiteflies, important insect vectors for plant viruses.

    Science.gov (United States)

    Gelman, Dale B; Pszczolkowski, Maciej A; Blackburn, Michael B; Ramaswamy, Sonny B

    2007-03-01

    Ecdysteroids and juvenile hormones (JHs) regulate many physiological events throughout the insect life cycle, including molting, metamorphosis, ecdysis, diapause, reproduction, and behavior. Fluctuation of whitefly ecdysteroid levels and the identity of the whitefly molting hormone (20-hydroxyecdysone) have only been reported within the last few years. An ecdysteroid commitment peak that is associated with the reprogramming of tissues for a metamorphic molt in many holometabolous and some hemimetabolous insect species was not observed in last nymphal instars of either the sweet potato whitefly, Bemisia tabaci (Biotype B), or the greenhouse whitefly, Trialeurodes vaporariorum. Ecdysteroids reach peak levels 1-2 days prior to the initiation of the nymphal-adult metamorphic molt. Adult eye and wing differentiation which signal the onset of this molt begin earlier in 4th instar T. vaporariorum (Stages 4 and 5, respectively) than in B. tabaci (Stage 6), and the premolt peak is 3-4 times greater in B. tabaci ( approximately 400 fg/microg protein) than in T. vaporariorum ( approximately 120 fg/microg protein). The JH of B. tabaci nymphs and eggs was found to be JH III, supporting the view that JHs I and II are, with rare exception, only present in lepidopteran insects. In B. tabaci eggs, JH levels were approximately 10 times greater on day 2/3 (0.44 fg/egg or 0.54 ng/g) than on day 5 (0.04 fg/egg or 0.054 ng/g) post-oviposition. Approximately, 1.4 fg/2nd-3rd instar nymph (0.36 ng/g) was detected. It is probable that the relatively high level of JH in day 2/3 eggs is associated with the differentiation of various whitefly tissues during embryonic development.

  9. Short-term and transgenerational effects of the neonicotinoid nitenpyram on susceptibility to insecticides in two whitefly species.

    Science.gov (United States)

    Liang, Pei; Tian, Yu-An; Biondi, Antonio; Desneux, Nicolas; Gao, Xi-Wu

    2012-10-01

    The cosmopolitan silverleaf whitefly, Bemisia tabaci which had coexisted with Trialeurodes vaporariorum in Northern China for many years, has become the dominant species in the last years. Recent reports show that it is gradually displacing the other greenhouse whitefly species. Neonicotinoid, which includes nitenpyram, is a major group of insecticides used against whiteflies in various crops. When exposed to low doses of insecticides, insects may develop resistance by adapting physiologically. The short- and long-term effects of nitenpyram on insecticide sensitivity in B. tabaci biotype B and T. vaporariorum adult populations have been compared in the present study. After being exposed to LC(25) of nitenpyram for 24 h, the B. tabaci biotype B adults showed no significant change in susceptibility to nitenpyram or to five other insecticides: imidacloprid, acetamiprid, abamectin, chlorpyrifos and beta-cypermethrin. By contrast, exposure to the LC(25) of nitenpyram for 24 h led to a significant increase in the susceptibility of T. vaporariorum to nitenpyram and imidacloprid, by 1.8- and 2-fold, respectively. When exposed for seven generations to the LC(25) of nitenpyram, B. tabaci developed 6-fold resistance to nitenpyram, and 3.1- and 5-fold cross-resistance to imidacloprid and acetamiprid, respectively, whereas T. vaporariorum developed lower resistance (3.7-fold) to the nitenpyram and very low cross-resistance to imidacloprid (2.5-fold). The higher adaptable nature of B. tabaci (demonstrated here in the case of nitenpyram) when exposed to low doses of insecticides may provide a selective advantage when competing with T. vaporariorum in crops.

  10. 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

  11. 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.

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

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    Karyna Rosario

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

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

    Science.gov (United States)

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

    2014-01-01

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

  14. Host-parasite interactions between whiteflies and their parasitoids.

    Science.gov (United States)

    Gelman, Dale B; Gerling, Dan; Blackburn, Michael B; Hu, Jing S

    2005-12-01

    There is relatively little information available concerning the physiological and biochemical interactions between whiteflies and their parasitoids. In this report, we describe interactions between aphelinid parasitoids and their aleyrodid hosts that we have observed in four host-parasite systems: Bemisia tabaci/Encarsia formosa, Trialeurodes vaporariorum/E. formosa, B. tabaci/Eretmocerus mundus, and T. lauri/Encarsia scapeata. In the absence of reported polydnavirus and teratocytes, these parasitoids probably inject and/or produce compounds that interfere with the host immune response and also manipulate host development to suit their own needs. In addition, parasitoids must coordinate their own development with that of their host. Although eggs are deposited under all four instars of B. tabaci, Eretmocerus larvae only penetrate 4th instar B. tabaci nymphs. A pre-penetrating E. mundus first instar was capable of inducing permanent developmental arrest in its host, and upon penetration stimulated its host to produce a capsule (epidermal in origin) in which the parasitoid larva developed. T. vaporariorum and B. tabaci parasitized by E. formosa initiated adult development, and, on occasion, produced abnormal adult wings and eyes. In these systems, the site of parasitoid oviposition depended on the host species, occurring within or pressing into the ventral ganglion in T. vaporariorum and at various locations in B. tabaci. E. formosa's final larval molt is cued by the initiation of adult development in its host. In the T. lauri-E. scapeata system, both the host whitefly and the female parasitoid diapause during most of the year, i.e., from June until the middle of February (T. lauri) or from May until the end of December (E. scapeata). It appears that the growth and development of the insects are directed by the appearance of new, young foliage on Arbutus andrachne, the host tree. When adult female parasitoids emerged in the spring, they laid unfertilized male

  15. 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

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    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

  16. Caracterización molecular de un begomovirus del tomate en el Valle del Cauca, Colombia, y búsqueda de fuentes de resistencia para el mejoramiento de la variedad Unapal Maravilla Molecular characterization of a begomovirus affecting tomato in the Cauca Valle - Colombia and identification of sources of resistance to improve the variety Unapal Maravilla

    Directory of Open Access Journals (Sweden)

    Ana Karine Martínez A

    2008-10-01

    Full Text Available Se caracterizó un virus transmitido por la mosca blanca Bemisia tabaci al tomate en el Valle del Cauca como una variante del Virus del mosaico amarillo del tomate (Tomato yellow mosaic virus = ToYMV. Plantas de tomate (FLA 496-11-6-1-0, FLA 478-6-3-1-11, FLA 456-4 y FLA 653-3-1-0 de 20 días de edad se confinaron en jaulas individuales con 10 individuos virulíferos de B. tabaci (biotipo B por planta, en condiciones de invernadero. La infección por el virus se confirmó por el desarrollo de los síntomas y las pruebas moleculares de PCR e hibridación dot blot. Las características agromorfológicas se evaluaron en campo en un diseño de bloques completos al azar con tres repeticiones. Las líneas FLA 653-3-1-0, FLA 496-11-6-1-0 y FLA 478-6-3-1-11 desarrollaron síntomas muy leves; el ADN viral fue apenas detectable para algunos individuos y presentaron características del fruto y rendimientos deseables.A virus transmitted by the whitefly Bemisia tabaci to tomato was characterized in the Cauca Valley like a variant of Tomato yellow mosaic virus (ToYMV. Artificial whitefly-mediated inoculation in the greenhouse was done with 20 days-old tomato plants (FLA 496-11-6-1-0, FLA 478-6-3-1-11, FLA 456-4 y FLA 653-3-1-0 exposed to 10 viruliferous individuals of B. tabaci (biotype B per plant in individual insect-proof cages. The presence of the begomovirus was evaluated by symptoms development and was confirmed using dot blot hybridization and PCR. Agronomical characteristics were evaluated in the field in a completely randomized blocks design with 3 replications. The lines FLA 653-3-1-0, FLA 496-11-6-1-0 and FLA 478-6-3-1-11 developed mild symptoms, viral DNA was barely detectable in some individuals, and they showed characteristics of the fruit and desirable yield.

  17. 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.

  18. The role of bacterial chaperones in the circulative transmission of plant viruses by insect vectors.

    Science.gov (United States)

    Kliot, Adi; Ghanim, Murad

    2013-06-01

    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. PMID:23783810

  19. How active ingredient localisation in plant tissues determines the targeted pest spectrum of different chemistries

    DEFF Research Database (Denmark)

    Buchholz, Anke; Trapp, Stefan

    2016-01-01

    BACKGROUND: The efficacies of four commercial insecticides and of two research compounds were tested against aphids (Aphis craccivora and Myzus persicae), whiteflies (Bemisia tabaci) and red-spotted spider mites (Tetranychus urticae) in intrinsic (oral administration), curative (direct contact...... information sets revealed that the intracellular localisation of active ingredients determines the performance of test compounds against different target pests because of different feeding behaviours: mites feed on mesophyll, and aphids and whiteflies mostly in the vascular system. Polar compounds have a slow...... adsorption into leaf cells and thus a favourable distribution into apoplast and xylem sap. Slightly lipophilic bases get trapped in vacuoles, which is a less suited place to control hemipteran pests but appropriate to control mites. Non-favourable cellular localisation led to a strong reduction...

  20. 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...

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

    Directory of Open Access Journals (Sweden)

    Julio Massaharu Marubayashi

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

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

    Science.gov (United States)

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

    2014-01-01

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

  3. 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.

  4. 番茄黄化曲叶病毒对温室白粉虱适合度的影响%Effects of tomato yellow leaf curl virus on the fitness of greenhouse whitefly

    Institute of Scientific and Technical Information of China (English)

    付雪; 赵奎军; 赵娜; 谭巍; 裴海英; 闫春秀; 叶乐夫

    2015-01-01

    with a higher hatching rate on infected tomato plants whereas the greenhouse whitefly laid relatively more eggs with a lower hatching rate. These results have implications for the integrated management of whitefly pests in high latitude areas.%【目的】温室白粉虱 Trialeurodes vaporariorum (Westwood)是为害北方地区花卉蔬菜的主要粉虱种类,烟粉虱 Bemisia tabaci (Gennadius)则在近些年逐渐频繁的花卉贸易活动中扩散至黑龙江省部分地区并取代了白粉虱成为当地温室害虫的优势物种,番茄黄化曲叶病毒(Tomato yellow leaf curl virus , TYLCV)是烟粉虱传播的一种重要双生病毒,对作物的危害十分严重,然而该病毒对本地白粉虱的影响及对烟粉虱与白粉虱种间竞争关系的影响尚待研究。【方法】本研究观察记录感染番茄黄化曲叶病毒的番茄植株上温室白粉虱和烟粉虱的种群动态及番茄形态和部分生理指标的变化。【结果】结果表明:1)有烟粉虱滋生的番茄植株矮小,根系发达;2)有白粉虱滋生的番茄略微矮粗,影响较小;3)感染病毒的番茄矮粗或矮小,根部无明显变化;4)染毒带虫相对于带虫处理而言,在白粉虱试验中,番茄植株矮小,根系生物量也骤减;与此相反,在烟粉虱试验中,番茄的反应相对缓和;5)此外,不同酶类对植株染毒的响应不同:AchE 酶活高不利于植株,而 GST 酶活高则有利于植株。【结论】总体而言:烟粉虱单独作用很不利于苗期番茄,白粉虱对苗期番茄没有明显的直接影响;而感染病毒会缓解烟粉虱对番茄的强烈刺激,而加重白粉虱对番茄的作用,即染毒使带白粉虱的苗期番茄生长发育受到明显抑制。与番茄变化情况相对应的是,染毒番茄上烟粉虱产卵较少,但在发育前期(从卵到伪蛹)存活率较高;染毒番茄上白粉虱产卵较多,但在前期存

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Caracterización molecular de un begomovirus del tomate en el Valle del Cauca, Colombia, y búsqueda de fuentes de resistencia para el mejoramiento de la variedad Unapal Maravilla

    Directory of Open Access Journals (Sweden)

    Ana Karine Martínez A

    2008-10-01

    Full Text Available Se caracterizó un virus transmitido por la mosca blanca Bemisia tabaci al tomate en el Valle del Cauca como una variante del Virus del mosaico amarillo del tomate (Tomato yellow mosaic virus = ToYMV. Plantas de tomate (FLA 496-11-6-1-0, FLA 478-6-3-1-11, FLA 456-4 y FLA 653-3-1-0 de 20 días de edad se confinaron en jaulas individuales con 10 individuos virulíferos de B. tabaci (biotipo B por planta, en condiciones de invernadero. La infección por el virus se confirmó por el desarrollo de los síntomas y las pruebas moleculares de PCR e hibridación dot blot. Las características agromorfológicas se evaluaron en campo en un diseño de bloques completos al azar con tres repeticiones. Las líneas FLA 653-3-1-0, FLA 496-11-6-1-0 y FLA 478-6-3-1-11 desarrollaron síntomas muy leves; el ADN viral fue apenas detectable para algunos individuos y presentaron características del fruto y rendimientos deseables.

  11. Rapid spread of tomato yellow leaf curl virus in China is aided differentially by two invasive whiteflies.

    Directory of Open Access Journals (Sweden)

    Huipeng Pan

    Full Text Available BACKGROUND: Tomato yellow leaf curl virus (TYLCV was introduced into China in 2006, approximately 10 years after the introduction of an invasive whitefly, Bemisia tabaci (Genn. B biotype. Even so the distribution and prevalence of TYLCV remained limited, and the economic damage was minimal. Following the introduction of Q biotype into China in 2003, the prevalence and spread of TYLCV started to accelerate. This has lead to the hypothesis that the two biotypes might not be equally competent vectors of TYLCV. METHODOLOGY/PRINCIPAL FINDINGS: The infection frequency of TYLCV in the field-collected B. tabaci populations was investigated, the acquisition and transmission capability of TYLCV by B and Q biotypes were compared under the laboratory conditions. Analysis of B. tabaci populations from 55 field sites revealed the existence of 12 B and 43 Q biotypes across 18 provinces in China. The acquisition and transmission experiments showed that both B and Q biotypes can acquire and transmit the virus, however, Q biotype demonstrated superior acquisition and transmission capability than its B counterparts. Specifically, Q biotype acquired significantly more viral DNA than the B biotype, and reached the maximum viral load in a substantially shorter period of time. Although TYLCV was shown to be transmitted horizontally by both biotypes, Q biotype exhibited significantly higher viral transmission frequency than B biotype. Vertical transmission result, on the other hand, indicated that TYLCV DNA can be detected in eggs and nymphs, but not in pupae and adults of the first generation progeny. CONCLUSIONS/SIGNIFICANCE: These combined results suggested that the epidemiology of TYLCV was aided differentially by the two invasive whiteflies (B and Q biotypes through horizontal but not vertical transmission of the virus. This is consistent with the concomitant eruption of TYLCV in tomato fields following the recent rapid invasion of Q biotype whitefly in China.

  12. 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

  13. 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

  14. 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

  15. 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

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    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

  16. 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

  17. 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

  18. 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

  19. Tropical Whitefly IPM Project.

    Science.gov (United States)

    Morales, Francisco J

    2007-01-01

    The Tropical Whitefly IPM Project (TWFP) is an initiative of the Systemwide IPM Programme of the Consultative Group on International Agricultural Research (CGIAR), financed by the Department for International Development (DFID) of the United Kingdom, the Danish International Development Agency (DANIDA), the United States Department of Agriculture (USDA) and Agency for International Development (USAID), the Australian Centre for International Agricultural Research (ACIAR), and the New Zealand Agency for International Development (NZAID), to manage whitefly pests and whitefly-transmitted viruses in the Tropics. Participating CGIAR and other international centers include the Centre for International Tropical Agriculture (CIAT); the International Institute of Tropical Agriculture (IITA); The International Potato Centre (CIP); the Asian Vegetable Research and Development Centre (AVRDC); and the International Centre of Insect Physiology and Ecology (ICIPE), in close collaboration with the National Resources Institute (NRI-UK); national agricultural research institutions; agricultural universities; and advanced agricultural research laboratories in Africa, Asia, Europe, the Pacific Region, and the Americas. The TWFP was launched in 1996 as five separate but closely linked subprojects targeting: (1) Bemisia tabaci as a vector of viruses affecting cassava and sweet potato in sub-Saharan Africa (IITA, NRI, CIP, CIAT); (2) B. tabaci as a vector of viruses in mixed cropping systems of Mexico, Central America, and the Caribbean (CIAT); (3) B. tabaci as a vector of viruses in mixed cropping systems of eastern and southern Africa (ICIPE, AVRDC); (4) B. tabaci as a vector of viruses in mixed cropping systems of Southeast Asia (AVRDC); (5) Trialeurodes vaporariorum as a pest in mixed cropping systems of the Andean highlands (CIAT); and (6) whiteflies as pests of cassava in South America (CIAT). Diagnostic surveys conducted in Phase I (1997-2000) clearly showed that the two main

  20. Tropical Whitefly IPM Project.

    Science.gov (United States)

    Morales, Francisco J

    2007-01-01

    The Tropical Whitefly IPM Project (TWFP) is an initiative of the Systemwide IPM Programme of the Consultative Group on International Agricultural Research (CGIAR), financed by the Department for International Development (DFID) of the United Kingdom, the Danish International Development Agency (DANIDA), the United States Department of Agriculture (USDA) and Agency for International Development (USAID), the Australian Centre for International Agricultural Research (ACIAR), and the New Zealand Agency for International Development (NZAID), to manage whitefly pests and whitefly-transmitted viruses in the Tropics. Participating CGIAR and other international centers include the Centre for International Tropical Agriculture (CIAT); the International Institute of Tropical Agriculture (IITA); The International Potato Centre (CIP); the Asian Vegetable Research and Development Centre (AVRDC); and the International Centre of Insect Physiology and Ecology (ICIPE), in close collaboration with the National Resources Institute (NRI-UK); national agricultural research institutions; agricultural universities; and advanced agricultural research laboratories in Africa, Asia, Europe, the Pacific Region, and the Americas. The TWFP was launched in 1996 as five separate but closely linked subprojects targeting: (1) Bemisia tabaci as a vector of viruses affecting cassava and sweet potato in sub-Saharan Africa (IITA, NRI, CIP, CIAT); (2) B. tabaci as a vector of viruses in mixed cropping systems of Mexico, Central America, and the Caribbean (CIAT); (3) B. tabaci as a vector of viruses in mixed cropping systems of eastern and southern Africa (ICIPE, AVRDC); (4) B. tabaci as a vector of viruses in mixed cropping systems of Southeast Asia (AVRDC); (5) Trialeurodes vaporariorum as a pest in mixed cropping systems of the Andean highlands (CIAT); and (6) whiteflies as pests of cassava in South America (CIAT). Diagnostic surveys conducted in Phase I (1997-2000) clearly showed that the two main

  1. 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

  2. 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

    Directory of Open Access Journals (Sweden)

    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

  3. 蔬菜粉虱的系统调查与监测技术%Systematic investigation and monitoring of whitefly pests in a vegetable ecosystem

    Institute of Scientific and Technical Information of China (English)

    任顺祥; 刘同先; 杜予州; 彭正强; 邱宝利; 戈峰

    2014-01-01

    由于烟粉虱Bemisia tabaci、温室白粉虱Trialeurodes vaporariorum等粉虱害虫在我国猖獗为害,我国已从种群动态监测到害虫综合治理开展了一系列研究。为了有一套统一、规范的标准,我们制定了保护地蔬菜与露地蔬菜生产上粉虱害虫的系统调查与监测技术规程,包括调查与监测的目的、样本大棚或田块的选择,粉虱各虫态发生数量的调查、监测与统计方法等,并根据保护地蔬菜与露地蔬菜的生长特点,提出了相应的粉虱害虫预测预报、防治阈值、防治对策及防控时间等技术措施。%Many species of whiteflies, including Bemisia tabaci and Trialeurodes vaporariorum, are important pests of vegetables, ornamentals and field crops. Numerous studies have been carried out on these species, from monitoring population dynamics to integrated management. In order to have a set of unified and standard rules for whitefly pest control, a series of technical standards have been formulated, including those for the monitoring and sampling of different species of whiteflies on different crops and data analysis for different whitefly instars. The prediction and forecasting of whitefly pests, their control threshold, control strategies and timing have been drafted according to the growth characteristics of different vegetables in both greenhouses and field conditions.

  4. Epidemiology and genetic diversity of criniviruses associated with tomato yellows disease in Greece.

    Science.gov (United States)

    Orfanidou, C G; Dimitriou, C; Papayiannis, L C; Maliogka, V I; Katis, N I

    2014-06-24

    Tomato chlorosis virus (ToCV) and Tomato infectious chlorosis virus (TICV) are two whitefly transmitted viruses which are classified in the genus Crinivirus of the family Closteroviridae. Both induce similar yellowing symptoms in tomato and are responsible for severe economic losses. ToCV is transmitted by Bemisia tabaci Gennadious, Trialeurodes vaporariorum Westwood and Trialeurodes abutilonea Haldeman, whereas TICV is transmitted only by T. vaporariorum. An extensive study was conducted during 2009-2012 in order to identify the virus species involved in tomato yellowing disease in Greece. Samples from tomato, other crops and weeds belonging to 44 species from 26 families were collected and analyzed using molecular methods. In addition, adult whiteflies were collected and analyzed using morphological characters and DNA markers. Results showed that TICV prevailed in tomato crops (62.5%), while ToCV incidence was lower (20.5%) and confined in southern Greece. ToCV was also detected in lettuce plants showing mild yellowing symptoms for the first time in Greece. Approximately 13% of the tested weeds were found to be infected, with TICV being the predominant virus with an incidence of 10.8%, whereas ToCV was detected only in 2.2% of the analyzed samples. These results indicate that the host range of TICV and ToCV in Greece is far more extensive than previously believed. T. vaporariorum was the most widespread whitefly species in Greece (80%), followed by B. tabaci (biotypes B and Q) (20%). Sequence analysis of the CP and CPm genes from Greek tomato and weed isolates of ToCV and TICV showed that even though both viruses have very wide host ranges their populations show very low molecular divergence.

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

    Science.gov (United States)

    Verbeek, Martin; van Bekkum, Petra J; Dullemans, Annette M; van der Vlugt, René A A

    2014-06-24

    Members of the genus Torradovirus (family Secoviridae, type species Tomato torrado virus, ToTV) are spherical plant viruses transmitted by the whitefly species Trialeurodes vaporariorum and Bemisia tabaci. Knowledge on the mode of vector transmission is lacking for torradoviruses. Here, the mode of transmission was determined for Tomato marchitez virus (ToMarV). A minimal acquisition access period (AAP) and inoculation access period (IAP) of approximately 2h each was required for its transmission by T. vaporariorum, while optimal transmission required an AAP and IAP of at least 16h and 8h, respectively. Whiteflies could retain the virus under non-feeding conditions for at least 8h without loss of transmission efficiency, but upon feeding on a non-host plant in between the AAP and IAP they retained the virus for no more than 8h. Similar conditions supported transmission of isolates of ToTV and Tomato chocolàte virus (ToChV) by T. vaporariorum and B. tabaci. Additionally, similar experiments revealed the banded-winged whitefly (Trialeurodes abutilonea) as a vector for all three virus species. The results are congruent with acquisition and retention periods for semi-persistent virus transmission. RT-PCR detection analysis of ToTV and ToMarV in the vector's body revealed their presence in the stylet, but not in the head where the pharynx of the foregut is located. The results altogether indicate a semi-persistent stylet-borne mode of vector transmission for torradoviruses. Additionally, this is the first group of spherical viruses transmitted by at least three different species of whiteflies.

  6. Host range and genetic diversity of croton yellow vein mosaic virus, a weed-infecting monopartite begomovirus causing leaf curl disease in tomato.

    Science.gov (United States)

    Pramesh, D; Mandal, Bikash; Phaneendra, Chigurupati; Muniyappa, V

    2013-03-01

    Croton yellow vein mosaic virus (CYVMV) is a widely occurring begomovirus in Croton bonplandianum, a common weed in the Indian subcontinent. In this study, CYVMV (genus Begomovirus, family Geminiviridae) was transmitted by whiteflies (Bemisia tabaci) to as many as 35 plant species belonging to 11 families, including many vegetables, tobacco varieties, ornamentals and weeds. CYVMV produced bright yellow vein symptoms in croton, whereas in all the other host species, the virus produced leaf curl symptoms. CYVMV produced leaf curl in 13 tobacco species and 22 cultivars of Nicotiana tabacum and resembled tobacco leaf curl virus (TobLCV) in host reactions. However, CYVMV was distinguished from TobLCV in four differential hosts, Ageratum conyzoides, C. bonplandianum, Euphorbia geniculata and Sonchus bracyotis. The complete genome sequences of four isolates originating from northern, eastern and southern India revealed that a single species of DNA-A and a betasatellite, croton yellow vein mosaic betasatellite (CroYVMB) were associated with the yellow vein mosaic disease of croton. The sequence identity among the isolates of CYVMV DNA-A and CroYVMB occurring in diverse plant species was 91.8-97.9 % and 83.3-100 %, respectively. The CYVMV DNA-A and CroYVMB generated through rolling-circle amplification of the cloned DNAs produced typical symptoms of yellow vein mosaic and leaf curling in croton and tomato, respectively. The progeny virus from both the croton and tomato plants was transmitted successfully by B. tabaci. The present study establishes the etiology of yellow vein mosaic disease of C. bonplandianum and provides molecular evidence that a weed-infecting monopartite begomovirus causes leaf curl in tomato.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Caracterización molecular de un begomovirus del tomate en el Valle del Cauca, Colombia, y búsqueda de fuentes de resistencia para el mejoramiento de la variedad Unapal Maravilla

    Directory of Open Access Journals (Sweden)

    Martínez Ana Karine

    2008-09-01

    Full Text Available Se caracterizó un virus transmitido por la mosca blanca Bemisia tabaci al tomate en el Valle del Cauca como una variante del Virus del mosaico amarillo del tomate (Tomato yellow mosaic virus = ToYMV. Plantas de tomate (FLA 496-11-6-1-0, FLA 478-6-3-1-11, FLA 456-4 y FLA 653-3-1-0 de 20 días de edad se confinaron en jaulas individuales con 10 individuos virulíferos de B. tabaci (biotipo B por planta, en condiciones de invernadero. La infección por el virus se confirmó por el desarrollo de los síntomas y las pruebas moleculares de PCR e hibridación dot blot. Las características agromorfológicas se evaluaron en campo en un diseño de bloques completos al azar con tres repeticiones. Las líneas FLA 653-3-1-0, FLA 496-11-6-1-0 y FLA 478-6-3-1-11 desarrollaron síntomas muy leves; el ADN viral fue apenas detectable para algunos individuos y presentaron características del fruto y rendimientos deseables.

  9. 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.

  10. Conditional fitness benefits of the Rickettsia bacterial symbiont in an insect pest.

    Science.gov (United States)

    Cass, Bodil N; Himler, Anna G; Bondy, Elizabeth C; Bergen, Jacquelyn E; Fung, Sierra K; Kelly, Suzanne E; Hunter, Martha S

    2016-01-01

    Inherited bacterial symbionts are common in arthropods and can have strong effects on the biology of their hosts. These effects are often mediated by host ecology. The Rickettsia symbiont can provide strong fitness benefits to its insect host, Bemisia tabaci, under laboratory and field conditions. However, the frequency of the symbiont is heterogeneous among field collection sites across the USA, suggesting that the benefits of the symbiont are contingent on additional factors. In two whitefly genetic lines collected from the same location, we tested the effect of Rickettsia on whitefly survival after heat shock, on whitefly competitiveness at different temperatures, and on whitefly competitiveness at different starting frequencies of Rickettsia. Rickettsia did not provide protection against heat shock nor affect the competitiveness of whiteflies at different temperatures or starting frequencies. However, there was a strong interaction between Rickettsia infection and whitefly genetic line. Performance measures indicated that Rickettsia was associated with significant female bias in both whitefly genetic lines, but in the second whitefly genetic line it conferred no significant fitness benefits nor conferred any competitive advantage to its host over uninfected whiteflies in population cages. These results help to explain other reports of variation in the phenotype of the symbiosis. Furthermore, they demonstrate the complex nature of these close symbiotic associations and the need to consider these interactions in the context of host population structure. PMID:26376661

  11. 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.

  12. 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.

  13. Primary Study on Systemic Action of Novel Neonicotiniod Insecticide IPP-10

    Institute of Scientific and Technical Information of China (English)

    Yuan Huizhu; Song Xiaoyu; Wu Zhongyan; Huang Qingchun; Qi Shuhua

    2007-01-01

    IPP-10 was one novel kind of neonicotinoid insecticide developed in recent years. The systemic action was studied by bioassay method in this paper. The results showed that IPP-10 had excellent translocation activity. It could be taken up by plant and further disttibuted acropetally with good root-systemic action. Wheat plants were cultured by IPP-10 solutions at concentrations of 1.0μg/mL, 5μg/mL, 10μg/mL, 25μg/mL and 50μg/mL, respectively. The control efficacy to wheat aphid was 94%, 98%, 100%, 100% and 100% at 24 hours later, respectively. The control efficacies to wheat aphids by root treatment were significantly better than that by spray method at the same concentration. These phenomena indicated that IPP-10 had good root-systemic action in wheat plant. Moreover, cotton seedlings were cultured with IPP-10 solution at concentration of 1.0μg/mL, 2.5μg/mL, 10μg/mL, 25μg/mL and 50μg/mL, respectively, their control efficacy to Bemisia tabaci adult was 3.8%, 7.3%, 42.1%, 78.0% and 88.5% at 72 hours later, respectively. These resuhs also indicated that IPP-10 had good root-systemic action in cotton plant.

  14. 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.

  15. Pepino mosaic virus and Tomato torrado virus: two emerging viruses affecting tomato crops in the Mediterranean basin.

    Science.gov (United States)

    Gómez, Pedro; Sempere, Raqueln; Aranda, Miguel A

    2012-01-01

    The molecular biology, epidemiology, and evolutionary dynamics of Pepino mosaic virus (PepMV) are much better understood than those of Tomato torrado virus (ToTV). The earliest descriptions of PepMV suggest a recent jump from nontomato species (e.g., pepino; Solanum muricatum) to tomato (Solanum lycopersicum). Its stability in contaminated plant tissues, its transmission through seeds, and the global trade of tomato seeds and fruits may have facilitated the global spread of PepMV. Stability and seed transmission also probably account for the devastating epidemics caused by already-established PepMV strains, although additional contributing factors may include the efficient transmission of PepMV by contact and the often-inconspicuous symptoms in vegetative tomato tissues. The genetic variability of PepMV is likely to have promoted the first phase of emergence (i.e., the species jump) and it continues to play an important role as the virus becomes more pervasive, progressing from regional outbreaks to pandemics. In contrast, the long-term progression of ToTV outbreaks is not yet clear and this may reflect factors such as the limited accumulation of the virus in infected plants, which has been shown to be approximately two orders of magnitude less than PepMV. The efficient dispersion of ToTV may therefore depend on dense populations of its principal vectors, Bemisia tabaci and Trialeurodes vaporariorum, as has been proposed for the necrogenic satellite RNA of Cucumber mosaic virus.

  16. Parasitoides de Trialeurodes vaporariorum Westwood, 1856 (Hemiptera: Aleyrodidae en cultivos de fríjol en García Rovira, Santander

    Directory of Open Access Journals (Sweden)

    José Arnoldo Granadillo-Cuello

    2014-07-01

    Full Text Available Background: The whitefly complex is one of the main entomological problems of this country, due to the large number of hosts and for their wide distribution. Two species of this complex are Bemisia tabaci and Trialeurodes vaporariorum; the latter has been identified as a pest of tomatoes, beans and snuff in the sampling area. Objective: Determine the species of parasitoids associated with Trialeurodes vaporariorum bean crop in four municipalities of the Province of Garcia Rovira, in the department of Santander. Methods: This investigation was conducted in the municipalities of Enciso, Málaga, Concepción and El Cerrito. Stages random sampling with a sample size of 50 leaflets per culture was grown. The parasitoids were collected through cameras recovery. The measures were, Total nymphs parasitized nymphs emerged parasitoids emerged parasitoids no, emerged nymphs. Results: Two species of the order Hymenoptera, identified as Encarsia pergandiella and Amitus fuscipennis recovered. The results indicate that parasitism levels range from 3% to 20% Amitus fuscipennis (Hemiptera: Aleyrodidae was present in 96.48% of the samples. Conclusions. Amitus fuscipennis is the most abundant parasitoid of Trialeurodes vaporariorum in natural conditions in the Province of Garcia Rovira Encarcia pergandiella is less abundant due to its little adaptation to the conditions of the study area.

  17. 粉虱座壳孢培养基的筛选试验%On the Selection of Culture Medium for Aschersonia Aleyrodis

    Institute of Scientific and Technical Information of China (English)

    邱君志

    2006-01-01

    虫生真菌粉虱座壳孢能有效地防治烟粉虱(Bemisia tabaci)和温室白粉虱(Trialeurodes vaporariorum)这两种世界性害虫.本文通过四因子三水平正交实验筛选出有利于粉虱座壳孢孢子萌发、菌丝生长和产孢的碳源、氮源、金属离子和维生素.结果表明,最有利于其萌发的营养因素分别是葡萄糖、牛肉浸膏、Cu2+和VC,最能促进生长的分别是蔗糖、牛肉浸膏、Zn2+和VB2,最有助于产孢的分别是葡萄糖、酵母浸粉、Mn2+和VB1.

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

    Science.gov (United States)

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

    2015-01-01

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

  19. New developments in insecticide resistance in the glasshouse whitefly (Trialeurodes vaporariorum) and the two-spotted spider mite (Tetranychus urticae) in the UK.

    Science.gov (United States)

    Gorman, Kevin; Hewitt, Fiona; Denholm, Ian; Devine, Gregor J

    2002-02-01

    A recent survey of insecticide resistance in two of the most problematic pests in UK glasshouses revealed some new developments. At least some individuals in all UK samples of Trialeurodes vaporariorum that were tested resisted the insect growth regulator (IGR) buprofezin. The most strongly resistant strains were unaffected by the field application rate of this compound, and even samples from populations that had never been exposed to buprofezin contained individuals that survived the highest concentration applied (10,000 mg litre-1). The field rate of buprofezin was shown to select for resistance through vapour action alone. The benzophenylurea teflubenzuron, an unrelated IGR, was cross-resisted by buprofezin-resistant individuals. There was no evidence of resistance to imidacloprid, but all T vaporariorum strains tested, regardless of origin, exhibited a high innate tolerance to nicotine, when compared with another whitefly species, Bemisia tabaci. Marked resistance to fenbutatin oxide and tebufenpyrad was found in single glasshouse populations of Tetranychus urticae, but these compounds and abamectin appeared to remain highly effective against all other strains collected.

  20. 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

  1. Synergistic interaction between the Potyvirus, Turnip mosaic virus and the Crinivirus, Lettuce infectious yellows virus in plants and protoplasts.

    Science.gov (United States)

    Wang, Jinbo; Turina, Massimo; Medina, Vicente; Falk, Bryce W

    2009-09-01

    Lettuce infectious yellows virus (LIYV), the type member of the genus Crinivirus in the family Closteroviridae, is specifically transmitted by the sweet potato whitefly (Bemisia tabaci) in a semipersistent manner. LIYV infections result in a low virus titer in plants and protoplasts, impeding reverse genetic efforts to analyze LIYV gene/protein functions. We found that synergistic interactions occurred in mixed infections of LIYV and Turnip mosaic virus (TuMV) in Nicotiana benthamiana plants, and these resulted in enhanced accumulation of LIYV. Furthermore, we examined the ability of transgenic plants and protoplasts expressing only the TuMV P1/HC-Pro sequence to enhance the accumulation of LIYV. LIYV RNA and protein titers increased by as much as 8-fold in these plants and protoplasts relative to control plants. LIYV infections remained phloem-limited in P1/HC-Pro transgenic plants, suggesting that enhanced accumulation of LIYV in these plants was due primarily to increased replication efficiency, not to greater spread.

  2. Mating and host density affect host feeding and parasitism in two species of whitefly parasitoids

    Institute of Scientific and Technical Information of China (English)

    Lian-Sheng Zang; Tong-Xian Liu; Fan Zhang; Shu-Sen Shi; Fang-Hao Wan

    2011-01-01

    The parasitoids in the genera of Encarsia and Eretmocerus(Hymenoptera:Aphelinidae)are important biological control agents of whiteflies,and some of them not only parasitize hosts but also kill them with strong host-feeding capacity.Two whitefly parasitoid species,Encarsia sophia and Eretmocerus melanoscutus were examined to determine if mating and host density affected their host feeding and parasitism.The whitefly host,Bemisia tabaci,was presented to these two wasp species in densities of 10,20,30,40,50 and 60 third-instar nymphs per clip cage.Mated whitefly parasitoid females fed on more hosts than unmated females under a range of host densities(under all six host densities for En.sophia; under the densities of 40 nymphs or more for Er.melanoscutus).Meanwhile,mated females parasitized more whitefly nymphs than unmated females under all host densities for both species.With increase of host density,mated or unmated Er.melanoscutus females killed more hosts by host feeding and parasitism.Mated En.sophia females killed more hosts by host feeding with increase of host density,whereas unmated females did not parasitze whitefly nymphs at all.Our results suggest that only mated female parasitoids with host-feeding behavior should be released in crop systems to increase their bio-control efficiency.

  3. Infectivity, effects on helper viruses and whitefly transmission of the deltasatellites associated with sweepoviruses (genus Begomovirus, family Geminiviridae).

    Science.gov (United States)

    Hassan, Ishtiaq; Orílio, Anelise F; Fiallo-Olivé, Elvira; Briddon, Rob W; Navas-Castillo, Jesús

    2016-01-01

    Begomoviruses (family Geminiviridae) are whitefly-transmitted viruses with single-stranded DNA genomes that are frequently associated with DNA satellites. These satellites include non-coding satellites, for which the name deltasatellites has been proposed. Although the first deltasatellite was identified in the late 1990s, little is known about the effects they have on infections of their helper begomoviruses. Recently a group of deltasatellites were identified associated with sweepoviruses, a group of phylogenetically distinct begomoviruses that infect plants of the family Convolvulaceae including sweet potato. In this work, the deltasatellites associated with sweepoviruses are shown to be transreplicated and maintained in plants by the virus with which they were identified, sweet potato leaf curl virus (SPLCV). These deltasatellites were shown generally to reduce symptom severity of the virus infection by reducing virus DNA levels. Additionally they were shown to be maintained in plants, and reduce the symptoms induced by two Old World monopartite begomoviruses, tomato yellow leaf curl virus and tomato yellow leaf curl Sardinia virus. Finally one of the satellites was shown to be transmitted plant-to-plant in the presence of SPLCV by the whitefly vector of the virus, Bemisia tabaci, being the first time a deltasatellite has been shown to be insect transmitted. PMID:27453359

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. Control of the Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), in Open-Field Tomatoes by Indigenous Natural Enemies Occurring in Israel.

    Science.gov (United States)

    Shaltiel-Harpaz, Liora; Gerling, Dan; Graph, Shaul; Kedoshim, Hendrika; Azolay, Lotem; Rozenberg, Tamir; Nachache, Yaakov; Steinberg, Shimon; Allouche, Arnon; Alon, Tamar

    2016-02-01

    The tomato leafminer, Tuta absoluta (Meyrick), had established in Israel by 2010, attacking both open-field tomatoes and greenhouse crops.We searched for its natural enemies in open-field tomatoes, and tried to determine their potential for controlling this pest. We surveyed the local natural enemies in open tomato fields and measured their impact on pest populations in an unsprayed field. We assessed the suppressive ability of the dominant hemipteran predator, Nesidiocoris tenuis Reuter, against T. absoluta under controlled laboratory conditions and evaluated the impact of its augmentation on T. absoluta control in open-field tomatoes. We found five natural enemy species:the predator, N. tenuis, two braconids, and two eulophids. Predation accounted for 64.5±9.2% (mean ± SE) of T. absoluta larval mortality, whereas parasitism accounted for 20.96±7.5%. Together, they eliminated the pest population at tomato harvest time. Under controlled conditions, predation by N. tenuis rose from 58 to 72% with increased density of T. absoluta, suggesting positive density dependence. The reduction of T. absoluta (83%) by N. tenuis was higher than that of Bemisia tabaci (32%), suggesting a preference of N. tenuis for T. absoluta. Augmentation of N.tenuis was as effective as conventional treatment insecticide treatment, and plant damage was low and did not seem to affect yield. Results indicate that reduced pesticide use enables indigenous natural enemies, particularly N.tenuis, to successfully control T. absoluta and prevent crop damage in open-field tomatoes.

  9. Biorational agents--mechanism and importance in IPM and IRM programs for controlling agricultural pests.

    Science.gov (United States)

    Ishaaya, I; Kontsedalov, S; Mazirov, D; Horowitz, A R

    2001-01-01

    Among the new approaches for controlling agricultural pests is the development of novel compounds affecting specific processes in insects such as chitin synthesis inhibitors, juvenile hormone mimics and ecdysone agonists. In addition, efforts have been made to develop compounds acting selectively on groups of insects by inhibiting or enhancing biochemical sites such as respiration (diafenthiuron), the nicotinyl acetylcholine receptors (imidacloprid and acetamiprid), the GABA receptors (avermectins), the salivary glands of sucking pests (pymetrozine) and others. Among the most recent novel insecticides with selective properties are novaluron, thiamethoxam, emamectin and spinosad. Novaluron (Rimon) is a novel chitin synthesis inhibitor that acts by both ingestion and contact. It is a powerful suppressor of lepidopteran larvae such as Spodoptera littoralis and Helicoverpa armigera (by ingestion) and of whiteflies such as Bemisia tabaci and Trialeurodes vaporariorum (by contact). Thiamethoxam (Actarn), a novel neonicotinoid acts specifically on aphids and whiteflies. Emamectin (Proclaim), an avermectin derivative acts on GABA receptor affecting diversity of insects such as mites, lepidopterans and thrips. Spinosad (Tracer) seems to act on both acetylcholine and GABA receptors affecting diversity of insect species and is considered an important agent for controlling the western flower thrips.

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

    Directory of Open Access Journals (Sweden)

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

    2010-07-01

    Full Text Available 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 transgenics resistant to leaf curl disease (CLCuD using Antisense (rep (Replicase protein gene wasdeveloped via Agrobacterium mediated transformation. A binary vector carrying the Antisense rep gene along with thenpt II (neomycin phospho transferase gene driven by CaMV-35S promoter and NOS (nopaline synthase terminator wasused for transformation. The confirmation of the rep and npt II genes in the transgenic plants were verified by PCR andintegration of T-DNA into the plant genome was confirmed by Southern analysis. The individual transgenics were raisedin the green house and screened for the virus resistance. T2 progeny analysis showed classical Mendelian pattern ofinheritance.

  11. 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

  12. Feeding by whiteflies suppresses downstream jasmonic acid signaling by eliciting salicylic acid signaling.

    Science.gov (United States)

    Zhang, Peng-Jun; Li, Wei-Di; Huang, Fang; Zhang, Jin-Ming; Xu, Fang-Cheng; Lu, Yao-Bin

    2013-05-01

    Phloem-feeding whiteflies in the species complex Bemisia tabaci cause extensive crop damage worldwide. One of the reasons for their "success" is their ability to suppress the effectual jasmonic acid (JA) defenses of the host plant. However, little is understood about the mechanisms underlying whitefly suppression of JA-regulated defenses. Here, we showed that the expression of salicylic acid (SA)-responsive genes (EDS1 and PR1) in Arabidopsis thaliana was significantly enhanced during feeding by whitefly nymphs. Whereas upstream JA-responsive genes (LOX2 and OPR3) also were induced, the downstream JA-responsive gene (VSP1) was repressed, i.e., whiteflies only suppressed downstream JA signaling. Gene-expression analyses with various Arabidopsis mutants, including NahG, npr-1, ein2-1, and dde2-2, revealed that SA signaling plays a key role in the suppression of downstream JA defenses by whitefly feeding. Assays confirmed that SA activation enhanced whitefly performance by suppressing downstream JA defenses.

  13. 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.

  14. 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.

  15. The Facultative Symbiont Rickettsia Protects an Invasive Whitefly against Entomopathogenic Pseudomonas syringae Strains.

    Science.gov (United States)

    Hendry, Tory A; Hunter, Martha S; Baltrus, David A

    2014-12-01

    Facultative endosymbionts can benefit insect hosts in a variety of ways, including context-dependent roles, such as providing defense against pathogens. The role of some symbionts in defense may be overlooked, however, when pathogen infection is transient, sporadic, or asymptomatic. The facultative endosymbiont Rickettsia increases the fitness of the sweet potato whitefly (Bemisia tabaci) in some populations through mechanisms that are not yet understood. In this study, we investigated the role of Rickettsia in mediating the interaction between the sweet potato whitefly and Pseudomonas syringae, a common environmental bacterium, some strains of which are pathogenic to aphids. Our results show that P. syringae multiplies within whiteflies, leading to host death, and that whiteflies infected with Rickettsia show a decreased rate of death due to P. syringae. Experiments using plants coated with P. syringae confirmed that whiteflies can acquire the bacteria at a low rate while feeding, leading to increased mortality, particularly when the whiteflies are not infected with Rickettsia. These results suggest that P. syringae may affect whitefly populations in nature and that Rickettsia can ameliorate this effect. This study highlights the possible importance of interactions among opportunistic environmental pathogens and endosymbionts of insects.

  16. Characterization of the symbiont Rickettsia in the mirid bug Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae).

    Science.gov (United States)

    Caspi-Fluger, A; Inbar, M; Steinberg, S; Friedmann, Y; Freund, M; Mozes-Daube, N; Zchori-Fein, E

    2014-12-01

    Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) is an omnivorous insect used for biological control. Augmentative release and conservation of N. tenuis have been used for pest control in tomato crops. Intracellular bacterial symbionts of arthropods are common in nature and have diverse effects on their hosts; in some cases they can dramatically affect biological control. Fingerprinting methods showed that the symbiotic complex associated with N. tenuis includes Wolbachia and Rickettsia. Rickettsia of N. tenuis was further characterized by sequencing the 16S rRNA and gltA bacterial genes, measuring its amount in different developmental stages of the insect by real-time polymerase chain reaction, and localizing the bacteria in the insect's body by fluorescence in situ hybridization. The Rickettsia in N. tenuis exhibited 99 and 96% similarity of both sequenced genes to Rickettsia bellii and Rickettsia reported from Bemisia tabaci, respectively. The highest amount of Rickettsia was measured in the 5th instar and adult, and the symbionts could be detected in the host gut and ovaries. Although the role played by Rickettsia in the biology of N. tenuis is currently unknown, their high amount in the adults and localization in the gut suggest that they may have a nutritional role in this insect.

  17. Conditional fitness benefits of the Rickettsia bacterial symbiont in an insect pest.

    Science.gov (United States)

    Cass, Bodil N; Himler, Anna G; Bondy, Elizabeth C; Bergen, Jacquelyn E; Fung, Sierra K; Kelly, Suzanne E; Hunter, Martha S

    2016-01-01

    Inherited bacterial symbionts are common in arthropods and can have strong effects on the biology of their hosts. These effects are often mediated by host ecology. The Rickettsia symbiont can provide strong fitness benefits to its insect host, Bemisia tabaci, under laboratory and field conditions. However, the frequency of the symbiont is heterogeneous among field collection sites across the USA, suggesting that the benefits of the symbiont are contingent on additional factors. In two whitefly genetic lines collected from the same location, we tested the effect of Rickettsia on whitefly survival after heat shock, on whitefly competitiveness at different temperatures, and on whitefly competitiveness at different starting frequencies of Rickettsia. Rickettsia did not provide protection against heat shock nor affect the competitiveness of whiteflies at different temperatures or starting frequencies. However, there was a strong interaction between Rickettsia infection and whitefly genetic line. Performance measures indicated that Rickettsia was associated with significant female bias in both whitefly genetic lines, but in the second whitefly genetic line it conferred no significant fitness benefits nor conferred any competitive advantage to its host over uninfected whiteflies in population cages. These results help to explain other reports of variation in the phenotype of the symbiosis. Furthermore, they demonstrate the complex nature of these close symbiotic associations and the need to consider these interactions in the context of host population structure.

  18. A transgenic approach to control hemipteran insects by expressing insecticidal genes under phloem-specific promoters

    Science.gov (United States)

    Javaid, Shaista; Amin, Imran; Jander, Georg; Mukhtar, Zahid; Saeed, Nasir A.; Mansoor, Shahid

    2016-01-01

    The first generation transgenic crops used strong constitutive promoters for transgene expression. However, tissue-specific expression is desirable for more precise targeting of transgenes. Moreover, piercing/sucking insects, which are generally resistant to insecticidal Bacillus thuringiensis (Bt) proteins, have emerged as a major pests since the introduction of transgenic crops expressing these toxins. Phloem-specific promoters isolated from Banana bunchy top virus (BBTV)