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reproductive incompatibility among genetic groups of bemisia tabaci supports the proposition that the whitefly is a cryptic species complex.the worldwide distribution and extensive genetic diversity of the whitefly bemisia tabaci has long been recognized. however, whether b. tabaci is a complex species or a species complex has been a subject of debate. recent phylogenetic analyses suggest that b. tabaci is a cryptic species complex composed of at least 24 morphologically indistinguishable species. here, we conducted crossing experiments and demonstrated reproductive incompatibility among three of the 24 putative species. our data an ...201020178675
mating behaviour, life history and adaptation to insecticides determine species exclusion between whiteflies.1. negative interspecific interactions, such as resource competition or reproductive interference, can lead to the displacement of species (species exclusion). 2. here, we investigated the effect of life history, mating behaviour and adaptation to insecticides on species exclusion between cryptic whitefly species that make up the bemisia tabaci species complex. we conducted population cage experiments independently in china, australia, the united states and israel to observe patterns of species ...201020163491
evidence for pre-zygotic reproductive barrier between the b and q biotypes of bemisia tabaci (hemiptera: aleyrodidae).the degree of reproductive isolation between the b and q biotypes of the whitefly bemisia tabaci (hemiptera: aleyrodidae) is currently not clear. laboratory experiments have shown that the two biotypes are capable of producing viable f1 hybrids but that these females are sterile as their f2 generation failed to develop, indicating, most likely, a post-zygotic reproductive barrier. here, we confirm, by molecular and ecological tools, that the b and q biotypes of israel are genetically isolated an ...201020158928
risk of damage to tomato crops by the generalist zoophytophagous predator nesidiocoris tenuis (reuter) (hemiptera: miridae).nesidiocoris tenuis (reuter) (hem. miridae) is a native zoophytophagous predator of the mediterranean region, and its populations colonize tomato crops when they are not heavily treated with insecticides. this generalist predator has a high capacity for controlling insect pests, and it is currently commercially produced and released in some areas to control bemisia tabaci (gennadius) (hem. aleyrodidae). however, its status as a pest and/or as beneficial is controversial. therefore, the aim of th ...201019366476
mapping and validation of qtls for resistance to aphids and whiteflies in melon.aphis gossypii and bemisia tabaci are severe hemipteran pests of melon crops and breeding for resistance to both insects is required to reduce pesticide use. resistance was evaluated for its effect on behaviour and biotic potential of both hemipterans in a population of recombinant inbred lines (rils) derived from the cross védrantais x pi 161375. insect variability was considered using two a. gossypii clones and two b. tabaci populations. two additive qtls affected the whiteflies. four additive ...201020180095
chlorotic curly stunt: a severe begomovirus disease of bottle gourd in northern india.bottle gourd (lagenaria siceraria) an important vegetable crop in india was observed to be affected by a chlorotic curly stunt disease (ccsd) during 2003-2006 in the vegetable growing areas of delhi and adjoining state of haryana. the affected plants are severely stunted and bear very small chlorotic and mildly curled leaves. incidence of the disease varied from 4.7 to 36%. the disease could be easily transmitted by whitefly, bemisia tabaci but not by sap. the causal virus was found to be a bego ...201023637479
differentiation of tomato yellow leaf curl virus and tomato yellow leaf curl sardinia virus using real-time taqman pcr.during the past four decades, tomato yellow leaf curl disease has become one of the major constraints in tomato production worldwide. in the mediterranean basin, several isolates from two major begomovirus species are involved in outbreaks and persistent epidemics. a real-time taqman pcr assay was developed and evaluated for the rapid and multiplex detection and differentiation of two begomoviruses often found in mixed infections in the region, tomato yellow leaf curl virus (tylcv) and tomato ye ...201020153376
prevalence of endosymbionts in bemisia tabaci populations and their in vivo sensitivity to antibiotics.bemisia tabaci can harbor both primary and secondary endosymbionts, and the specific endosymbionts can differ among different b. tabaci biotypes. this study determined (1) the prevalence of the primary endosymbiont portiera aleyrodidarum and secondary endosymbionts arsenophonus and wolbachia in two invasive biotypes (b and q) and one indigenous biotype (cv) in china and (2) the in vivo effect of three antibiotics (tetracycline, ampicillin trihydrate, and rifampicin) against the endosymbionts; if ...201020217091
insecticidal activity against bemisia tabaci biotype b of peel essential oil of citrus sinensis var. pear and citrus aurantium cultivated in northeast brazil.the fumigant action of peel essential oils of citrus sinensis var. pear (pear orange = po) and c. aurantium (bitter orange = bo) from the northeast of brazil were evaluated against bemisia tabaci biotype b and compared with eugenol as a positive control. the oil concentration in the po at 8.5 microl/l of air caused 97% mortality, while the oil concentration of bo at 9.5 microl/l of air caused 99% mortality. however, the lc50 estimates for both oils (lc50 = 3.80 microl/l of air for po and lc50 = ...201021213990
co-infection and localization of secondary symbionts in two whitefly species.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 symbio ...201020462452
host range and complete genome sequence of cucurbit chlorotic yellows virus, a new member of the genus crinivirus.cucurbit chlorotic yellows virus (ccyv) causes chlorotic yellows on cucumber (cucumis sativus) and melon (cucumis melo) and is transmitted by bemisia tabaci biotype b and q whiteflies. to characterize the host range of ccyv, 21 cucurbitaceous and 12 other plant species were inoculated using whitefly vectors. all tested cucumis spp. except cucumis anguria and cucumis zeyheri were systemically infected with ccyv, although infection rates varied among species. citrullus lanatus, cucurbita pepo, and ...201020465411
inoculation of tomato plants (solanum lycopersicum) with growth-promoting bacillus subtilis retards whitefly bemisia tabaci development.root inoculation of tomato (solanum lycopersicum) plants with a bacillus subtilis strain beb-dn (bsdn) isolated from the rhizosphere of cultivated potato plants was able to promote growth and to generate an induced systemic resistance (isr) response against virus-free bemisia tabaci. growth promotion was evident 3 weeks after inoculation. no changes in oviposition density, preference and nymphal number in the early stages of b. tabaci development were observed between bsdn-treated plants and con ...201020041333
viral infection of tobacco plants improves performance of bemisia tabaci but more so for an invasive than for an indigenous biotype of the whitefly.the ecological effects of plant-virus-vector interactions on invasion of alien plant viral vectors have been rarely investigated. we examined the transmission of tomato yellow leaf curl china virus (tylccnv) by the invasive q biotype and the indigenous zhj2 biotype of the whitefly bemisia tabaci, a plant viral vector, as well as the influence of tylccnv-infection of plants on the performance of the two whitefly biotypes. both whitefly biotypes were able to acquire viruses from infected plants an ...201020043350
induced defense by bemisia tabaci biotype b (hemiptera: aleyrodidae) in tobacco against myzus persicae (hemiptera: aphididae).myzus persicae and bemisia tabaci are serious pests of tobacco and can occur simultaneously on the same plant. we found that tobacco plants infested by whiteflies had fewer aphids than those without whiteflies. to determine whether b. tabaci feeding could induce plant defense against aphids locally and systemically, we determined the effects of b. tabaci on several biological parameters of m. persicae on tobacco. infestation of b. tabaci nymphs reduced survival rates of m. persicae by 30.0%. in ...201020550802
effects of food deprivation on host feeding and parasitism of whitefly parasitoids.most whitefly parasitoids kill whiteflies in one of two ways, by piercing the whitefly body with the ovipositor and laying an egg or by piercing the body and feeding on host fluids. the effects of food deprivation on host-feeding and parasitizing capacity of the whitefly parasitoids eretmocerus melanoscutus and encarsia formosa (hymenoptera: aphelinidae) were determined in this study. we investigated the effects of various food-deprivation durations (0, 3, 6, 10, and 24 h, and 20% honey solution ...201020550806
change in the biotype composition of bemisia tabaci in shandong province of china from 2005 to 2008.certain biotypes of the bemisia tabaci (gennadius) (hemiptera: aleyrodidae) complex cause extensive damage and are important pests and virus vectors in agricultural crops throughout the world. among the most invasive and well studied are the b and q biotypes. recent reports in shandong province, china, have indicated that the q biotype was introduced there in approximately 2005, whereas the b biotype has been established there for approximately 10 yr. even so, the present distribution of the two ...201020550819
flufenerim, a novel insecticide acting on diverse insect pests: biological mode of action and biochemical aspects.a new chemical compound was tested for its insecticidal activity against several major insect pests. the compound, called "flufenerim", has a core pyrimidine structure and an unknown mode of action and showed potent activity against the sweet potato whitefly bemisia tabaci (gennadius), the green peach aphid myzus persicae (sulzer), and the african cotton leafworm spodoptera littoralis (boisduval); however, it did not show any activity against two thrips species: western flower thrips frankliniel ...201020958045
phylogenetic analysis and inflow route of tomato yellow leaf curl virus (tylcv) and bemisia tabaci in korea.tomato yellow leaf curl virus (tylcv) is a member of the genus begomovirus of the family geminiviridae, members of which are characterized by closed circular single-stranded dna genomes of 2.7-2.8 kb in length, and include viruses transmitted by the bemisia tabaci whitefly. no reports of tylcv in korea are available prior to 2008, after which tylcv spread rapidly to most regions of the southern korean peninsula (gyeongsang-do, jeolla-do and jeju-do). fifty full sequences of tylcv were analyzed i ...201020981497
prevalence of wolbachia supergroups a and b in bemisia tabaci (hemiptera: aleyrodidae) and some of its natural enemies.wolbachia, a bacterial symbiont, is maternally transmitted in arthropods and nematodes. we report a systematic survey of wolbachia taxonomy in the sweetpotato whitefly, bemisia tabaci (gennadius) (hemiptera: aleyrodidae), and in some of its natural enemies. for the first time, wolbachia infections in b. tabaci are correlated with various whitefly genetic groups, host plants, and natural enemies as well as with geographical regions. polymerase chain reaction using 16s rdna and fisz genes revealed ...201021061989
release of hormones from conjugates: chloroplast expression of β-glucosidase results in elevated phytohormone levels associated with significant increase in biomass and protection from aphids or whiteflies conferred by sucrose esters.transplastomic tobacco (nicotiana tabacum) plants expressing β-glucosidase (bgl-1) show modified development. they flower 1 month earlier with an increase in biomass (1.9-fold), height (1.5-fold), and leaf area (1.6-fold) than untransformed plants. trichome density on the upper and lower leaf surfaces of bgl-1 plants increase by 10- and 7-fold, respectively, harboring 5-fold more glandular trichomes (as determined by rhodamine b staining), suggesting that bgl-1 lines produce more sugar esters th ...201021068365
tomato yellow leaf curl viruses: ménage à trois between the virus complex, the plant and the whitefly vector.tomato yellow leaf curl disease (tylcd) is one of the most devastating viral diseases affecting tomato crops in tropical, subtropical and temperate regions of the world. here, we focus on the interactions through recombination between the different begomovirus species causing tylcd, provide an overview of the interactions with the cellular genes involved in viral replication, and highlight recent progress on the relationships between these viruses and their vector, the whitefly bemisia tabaci. t ...201020618703
the transmission efficiency of tomato yellow leaf curl virus by the whitefly bemisia tabaci is correlated with the presence of a specific symbiotic bacterium species.tomato yellow leaf curl virus (tylcv) (geminiviridae: begomovirus) is exclusively vectored by the whitefly bemisia tabaci (gennadius) (hemiptera: aleyrodidae). tylcv transmission depends upon a 63-kda groel protein produced by the vector's endosymbiotic bacteria. b. tabaci is a species complex comprising several genetically distinct biotypes that show different secondary-symbiont fauna. in israel, the b biotype harbors hamiltonella, and the q biotype harbors wolbachia and arsenophonus. both biot ...201020631135
an invasive whitefly feeding on a virus-infected plant increased its egg production and realized fecundity.plant-pathogenic begomoviruses have a complex association with their insect vectors. the interactions of begomoviruses and reproduction of their vectors are poorly understood. bemisia tabaci is known to transmit many begomoviruses, and the spread of b. tabaci, especially the b and q 'biotypes', has been accompanied by the epidemics of begomoviruses. one of these identified disease-causing agents was tomato yellow leaf curl china virus (tylccnv).201020676356
insecticide resistance in field populations of bemisia tabaci (hemiptera: aleyrodidae) in west africa.the tobacco whitefly, bemisia tabaci gennadius (hemiptera: aleyrodidae), has developed a high degree of resistance to several chemical classes of insecticides throughout the world. to evaluate the resistance status in west africa, eight insecticides from different chemical families were tested using the leaf-dip method on four field populations collected from cotton in benin, togo and burkina faso.201020721972
neonicotinoid insecticides: historical evolution and resistance mechanisms.the use ofneonicotinoid insecticides has grown considerably since their introduction in 1990s. they are used extensively for the control of agriculturally important crop pests and also in the control of cat and dog fleas. imidacloprid exploited through an elaborated structural and substituent optimization of nithiazine was launched to market in 1990. the selectivity ofneonicotinoid compounds for insect species has been attributed to their binding on nicotinic acetylcholine receptors in which the ...201020737790
incidence and characterisation of resistance to neonicotinoid insecticides and pymetrozine in the greenhouse whitefly, trialeurodes vaporariorum westwood (hemiptera: aleyrodidae).trialeurodes vaporariorum (westwood), also known as the greenhouse whitefly, is a serious pest of protected vegetable and ornamental crops in most temperate regions of the world. neonicotinoid insecticides are used widely to control this species, although resistance has been reported and may be becoming widespread.201020799247
genetic identity of the bemisia tabaci species complex and association with high cotton leaf curl disease (clcud) incidence in pakistan.the cotton whitefly, bemisia tabaci (gennadius), is a cryptic species complex, and members of the complex have become serious pests in pakistan because of their feeding and their ability to transmit cotton leaf curl virus (clcuv). here, an analysis was made of the identity of b. tabaci collected from cotton and a range of non-cotton hosts in the cotton-growing zones in punjab and sindh, the main cotton-producing provinces of pakistan, using a portion of the mitochondrial cytochrome oxidase 1 gen ...201021308956
extraordinary resistance to insecticides reveals exotic q biotype of bemisia tabaci in the new world.a strain of the whitefly bemisia tabaci (gennadius) possessing unusually high levels of resistance to a wide range of insecticides was discovered in 2004 in the course of routine resistance monitoring in arizona. the multiply resistant insects, collected from poinsettia (euphorbia pulcherrima willd. ex klotzsch) plants purchased at a retail store in tucson, were subjected to biotype analysis in three laboratories. polyacrylamide gel electrophoresis of naphthyl esterases and sequencing of the mit ...201021309242
further insights into the strange role of bacterial endosymbionts in whitefly, bemisia tabaci: comparison of secondary symbionts from biotypes b and q in china.the percentage infection of secondary symbionts (ss) (wolbachia, arsenophonus, rickettsia, hamiltonella, fritschea and cardinium) in the exotic bemisia tabaci (genn.) invaders, commonly known as biotypes b and q from china, were determined by pcr. in total, 373 biotype b and 1830 biotype q individuals were screened for the presence of ss. biotype b was more abundant than biotype q from 2005 to 2006, and biotype q was more abundant from 2007 to 2009. each of the ss, with the exception of fritsche ...201121329550
resistance to tomato yellow leaf curl virus accumulation in the tomato wild relative solanum habrochaites associated with the c4 viral protein.tomato yellow leaf curl disease (tylcd) is a severe threat to tomato crops worldwide and is caused by tomato yellow leaf curl virus (tylcv) and several other begomoviruses (genus begomovirus, family geminiviridae). host plant resistance is the best tylcd control method but limited sources of resistance are available. in this study, two solanum habrochaites tylcd-resistance sources, eelm-388 and eelm-889, were found after a wide germplasm screening and were further characterized. a consistent res ...201121405986
rapid spread of a bacterial symbiont in an invasive whitefly is driven by fitness benefits and female bias.maternally inherited bacterial symbionts of arthropods are common, yet symbiont invasions of host populations have rarely been observed. here, we show that rickettsia sp. nr. bellii swept into a population of an invasive agricultural pest, the sweet potato whitefly, bemisia tabaci, in just 6 years. compared with uninfected whiteflies, rickettsia-infected whiteflies produced more offspring, had higher survival to adulthood, developed faster, and produced a higher proportion of daughters. the symb ...201121474763
symbiont diversity and non-random hybridization among indigenous (ms) and invasive (b) biotypes of bemisia tabaci.the whitefly bemisia tabaci (hemiptera: aleyrodidae) is a worldwide pest and a vector of numerous plant viruses. b. tabaci is composed of dozens of morphologically indistinguishable biotypes and its taxonomic status is still controversial. this phloem-feeder harbours the primary symbiont portiera aleyrodidarum and potentially six secondary symbionts: cardinium, arsenophonus, hamiltonella, rickettsia, wolbachia and fritschea. in the southwest indian ocean, la réunion hosts two biotypes of this sp ...201121476990
complete nucleotide sequence of croton yellow vein mosaic virus and dna-β associated with yellow vein mosaic disease of jatropha gossypifolia in india.a severe yellow vein mosaic disease was noticed on several jatropha gossypifolia plants growing nearby agriculture fields at lucknow, india. diseased plants exhibited yellow vein mosaic, leaf deformation, vein swelling and stunting. a population of whiteflies (bemisia tabaci) was also noticed in the vicinities; therefore, begomovirus infection was suspected. to confirm begomovirus association, total dna was isolated from symptomatic leaf samples and subjected to pcr using dna-a, dna-b and dna-β- ...201121479677
contact and fumigant toxicity of plant essential oils and efficacy of spray formulations containing the oils against b- and q-biotypes of bemisia tabaci.background: the contact + fumigant toxicity of 92 plant essential oils and control efficacy of 18 experimental spray formulations containing nine selected essential oils (0.5 and 0.1% sprays) and six commercial insecticides to females from b- and q-biotypes of bemisia tabaci were evaluated using vapour-phase mortality and spray bioassays. results: garlic and oregano (lc(50) , 0.15 ml cm(-3) ) were the most toxic oils against b- and q-biotype females. strong fumigant toxicity to both biotype fema ...201121480461
genetic diversity, geographical range and origin of bemisia tabaci (hemiptera: aleyrodidae) indian ocean ms.the whitefly bemisia tabaci is a pest vector of begomoviruses on crops worldwide. bemisia tabaci is composed of a complex of cryptic species which barely interbreed. an exception is the ms from the south west indian ocean (swio), which crosses in low proportions with the exotic b. the ms, together with b and q is part of the same phylogenetic clad. to infer the genetic structure, the geographical range and putative origin of this putative species, microsatellite data and mitochondrial dna (cytoc ...201121492491
effects of selected fertilizers on the life history of bemisia tabaci (hemiptera: aleyrodidae) biotype b.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 ass ...201121510203
molecular characterization and oxidative stress response of an intracellular cu/zn superoxide dismutase (cuznsod) of the whitefly, bemisia tabaci.superoxide dismutases (sods) are important for the survival of insects under environmental and biological stresses; however, little attention has been devoted to the functional characterization of sods in whitefly. in this study, an intracellular copper/zinc superoxide dismutase of whitefly (bemisia tabaci) (bt-cuznsod) was cloned. sequence analysis indicated that the full length cdna of bt-cuznsod is of 907 bp with a 471 bp open reading frame encoding 157 amino acids. the deduced amino acid seq ...201121541989
biological activity of natural phytoecdysteroids from ajuga iva against the sweetpotato whitefly bemisia tabaci and the persea mite oligonychus perseae.background: ecdysteroids are steroid hormones that control moulting and govern several changes during metamorphoses in arthropods. the discovery of the same molecules (phytoecdysteroids) in several plant species displayed a wide array of rather beneficial agricultural impact. many representatives of the genus ajuga plants contain phytoecdysteroids with a 5β-7-ene-6-one system exhibiting physiological activities in insects. results: by means of chromatographic (silica gel column, tlc) and lc-ms, ...201121604353
whitefly resistance traits derived from the wild tomato solanum pimpinellifollium affect the preference and feeding behavior of bemisia tabaci and reduce the spread of tomato yellow leaf curl virus.breeding of tomato genotypes that limit whitefly (bemisia tabaci) access and feeding might reduce the spread of tomato yellow leaf curl virus (tylcv), a begomovirus (genus begomovirus, family geminiviridae) that is the causal agent of tomato yellow leaf curl disease. tylcv is restricted to the phloem and is transmitted in a persistent manner by b. tabaci. the tomato breeding line abl 14-8 was developed by introgressing type iv leaf glandular trichomes and secretion of acylsucroses from the wild ...201121615206
[adult oviposition and larvae feeding behavior of spodoptera litura (lepidoptera: noctuidae) on tobacco plants after infested by b-biotype bemisia tabaci (homoptera: aleyrodidae)].to understand the effects of the defense responses of tobacco plants induced by the infesting of b-biotype bemisia tabaci to spodoptera litura, and to explore the mechanisms of the interspecific interactions between b-biotype b. tabaci and s. litura, a laboratory experiment was conducted to study the effects of tobacco plants after infested by b-biotype b. tabaci on the adult oviposition selection and the larvae feeding, anti-feeding, and other feeding behaviors of s. litura. comparing with that ...201121812310
suppressors of rna silencing encoded by the components of the cotton leaf curl begomovirus-betasatellite complex.begomoviruses (family geminiviridae) are single-stranded dna viruses transmitted by the whitefly bemisia tabaci. many economically important diseases in crops are caused by begomoviruses, particularly in tropical and subtropical environments. these include the betasatellite-associated begomoviruses causing cotton leaf curl disease (clcud) that causes significant losses to a mainstay of the economy of pakistan, cotton. rna interference (rnai) or gene silencing is a natural defense response of pla ...201121751853
a novel synthetic quantification standard including virus and internal report targets: application for the detection and quantification of emerging begomoviruses on tomato.abstract: background: begomovirus is a genus of phytopathogenic single-stranded dna viruses, transmitted by the whitefly bemisia tabaci. this genus includes emerging and economically significant viruses such as those associated with tomato yellow leaf curl disease, for which diagnostic tools are needed to prevent dispersion and new introductions. five real-time pcrs with an internal tomato reporter gene were developed for accurate detection and quantification of monopartite begomoviruses, includ ...201121819593
adulticidal activity of phthalides identified in cnidium officinale rhizome to b- and q-biotypes of bemisia tabaci.the residual contact toxicity of three benzofuranoids (z)-butylidenephthalide (1), (3s)-butylphthalide (2), and (z)-ligustilide (3) identified in the rhizome of cnidium officinale (apiaceae) to b- and q-biotype females of bemisia tabaci was evaluated using a leaf-dip bioassay. results were compared with those of eight conventional insecticides. based on 24 h lc(50) values, (z)-butylidenephthalide (254 ppm) and (z)-ligustilide (268 ppm) were more toxic than (3s)-butylphthalide (339 ppm) against b ...201121728333
rickettsia 'in' and 'out': two different localization patterns of a bacterial symbiont in the same insect species.intracellular symbionts of arthropods have diverse influences on their hosts, and their functions generally appear to be associated with their localization within the host. the effect of localization pattern on the role of a particular symbiont cannot normally be tested since the localization pattern within hosts is generally invariant. however, in israel, the secondary symbiont rickettsia is unusual in that it presents two distinct localization patterns throughout development and adulthood in i ...201121712994
Interspecific Interactions Between Bemisia tabaci Biotype B and Trialeurodes vaporariorum (Hemiptera: Aleyrodidae).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 toma ...201122182623
Horizontal transmission of the insect symbiont Rickettsia is plant-mediated.Bacteria in the genus Rickettsia, best known as vertebrate pathogens vectored by blood-feeding arthropods, can also be found in phytophagous insects. The presence of closely related bacterial symbionts in evolutionarily distant arthropod hosts presupposes a means of horizontal transmission, but no mechanism for this transmission has been described. Using a combination of experiments with live insects, molecular analyses and microscopy, we found that Rickettsia were transferred from an insect hos ...201122113034
yellowing disease in zucchini squash produced by mixed infections of cucurbit yellow stunting disorder virus and cucumber vein yellowing virus.zucchini squash is host to cucurbit yellow stunting disorder virus (cysdv), a member of the genus crinivirus, and cucumber vein yellowing virus (cvyv), a member of the genus ipomovirus, both transmitted by the whitefly bemisia tabaci. field observations suggest the appearance of new symptoms observed on leaves of zucchini squash crops when both viruses were present. when infected during controlled experiments with cysdv only, zucchini plants showed no obvious symptoms and the virus titer decreas ...201121999160
molecular identification of a new begomovirus associated with yellow mosaic disease of jatropha gossypifolia in india.yellow mosaic disease was observed on jatropha gossypifolia plants growing in kathaupahadi, madhya pradesh, india, and whiteflies (bemisia tabaci) were found in the vicinity. association of a new begomovirus with yellow mosaic disease of j. gossypifolia has been detected by pcr using begomovirus dna-a-specific primers. the complete dna-a genome (~2.7 kb) of this virus isolate was amplified by rolling-circle amplification (rca) followed by digestion with bam hi. the ~2.7-kb amplicons was cloned a ...201121971870
pinellia ternata agglutinin expression in chloroplasts confers broad spectrum resistance against aphid, whitefly, lepidopteran insects, bacterial and viral pathogens.broad spectrum protection against different insects and pathogens requires multigene engineering. however, such broad spectrum protection against biotic stress is provided by a single protein in some medicinal plants. therefore, tobacco chloroplasts were transformed with the agglutinin gene from pinellia ternata (pta), a widely cultivated chinese medicinal herb. pinellia ternata agglutinin (pta) was expressed up to 9.2% of total soluble protein in mature leaves. purified pta showed similar hemag ...201122077160
distribution and dynamics of bemisia tabaci invasive biotypes in central china.the tobacco whitefly, bemisia tabaci (gennadius), causes severe crop losses in many agricultural systems. the worst of these losses are often associated with the invasion and establishment of specific whitefly biotypes. in a comprehensive survey of biotypes present in central china between 2005 and 2007, we obtained 191 samples of b. tabaci from 19 districts in hubei province and its surrounds. biotypes were identified by rapd-pcr and by sequencing the mitochondrial cytochrome oxidase i gene (mt ...201120822556
acquisition of lettuce infectious yellows virus by bemisia tabaci perturbs the transmission of lettuce chlorosis virus.viruses in the genus crinivirus infect diverse plant species and are transmitted by specific whitefly vectors, but the basis for vector specific transmission remains poorly understood. here, we demonstrated that purified virion preparations of lettuce chlorosis virus (lcv) contained filamentous particles that were consistently transmitted to plants by whiteflies (bemisia tabaci biotypes a and b) following membrane feeding, suggesting that the preparations contained biologically active virions wi ...201121211541
global analysis of the transcriptional response of whitefly to tomato yellow leaf curl china virus reveals the relationship of coevolved adaptations.the begomoviruses are the largest and most economically important group of plant viruses transmitted exclusively by the whitefly bemisia tabaci in a circulative, persistent manner. the circulation of the viruses within the insect vectors involves complex interactions between virus and vector components; however, the molecular mechanisms of these interactions remain largely unknown. here we investigated the transcriptional response of the invasive b. tabaci middle east-asia minor 1 species to tom ...201121270146
Sweepoviruses cause disease in sweet potato and related Ipomoea spp.: fulfilling Koch's postulates for a divergent group in the genus begomovirus.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 ...201122073314
molecular characterization of bemisia tabaci populations in tunisia: genetic structure and evidence for multiple acquisition of secondary symbionts.a survey was conducted during 2009-2010 seasons to identify the distribution of bemisia tabaci (gennadius) biotypes in tunisia. the genetic affiliation of collected populations was determined by polymerase chain reaction (pcr)-restriction fragment-length polymorphism (taqi) of the mitochondrial cytochrom oxidase i (mtcoi) gene. results, validated by sequencing and phylogenetic analysis, allowed the clustering of sampled sweetpotato whiteflies into b and q biotypes. as b. tabaci harbors the obli ...201122251681
insights into the transcriptomics of polyphagy: bemisia tabaci adaptability to phenylpropanoids involves coordinated expression of defense and metabolic genes.the whitefly bemisia tabaci is a major generalist agricultural pest of field and horticultural crops world-wide. despite its importance, the molecular bases of defense mechanisms in b. tabaci against major plant secondary defense compounds, such as the phenylpropanoids, remain unknown. our experimental system utilized transgenic nicotiana tabacum plants constitutively expressing the pap1/atmyb75 transcription factor which activates relatively specifically the phenylpropanoid/flavonoids biosynthe ...201122212826
effect of methomyl and oxamyl soil applications on early control of nematodes and insects.methomyl is a widely used carbamate insecticide that has traditionally been applied as a foliar spray. more recently, methomyl has been labeled as a soil application via drip chemigation. not much is known about the insecticidal and nematicidal potential of soil-applied methomyl. methomyl soil applications were evaluated for their potential to control soil nematodes and foliar insect pests in a series of lab and greenhouse tests.201121438120
comparing the regional epidemiology of the cassava mosaic and cassava brown streak virus pandemics in africa.the rapid geographical expansion of the cassava mosaic disease (cmd) pandemic, caused by cassava mosaic geminiviruses, has devastated cassava crops in 12 countries of east and central africa since the late 1980s. region-level surveys have revealed a continuing pattern of annual spread westward and southward along a contiguous 'front'. more recently, outbreaks of cassava brown streak disease (cbsd) were reported from uganda and other parts of east africa that had been hitherto unaffected by the d ...201121549776
biological characterization of sulfoxaflor, a novel insecticide.the commercialization of new insecticides is important for ensuring that multiple effective product choices are available. in particular, new insecticides that exhibit high potency and lack insecticidal cross-resistance are particularly useful in insecticide resistance management (irm) programs. sulfoxaflor possesses these characteristics and is the first compound under development from the novel sulfoxamine class of insecticides.201121308958
asymmetry in thermal tolerance trade-offs between the b and q sibling species of bemisia tabaci (hemiptera: aleyrodidae).we investigated life history trade-offs related to thermal tolerance in two sibling species, commonly referred to as the b and q biotypes, of bemisia tabaci. we focused on basal resistance to short unpredicted heat stress, which reflects the organism investment, during both optimal and stressful conditions, in insuring its survival. at 27 °c, the relative reproductive performance of b was seven-fold higher than q. after short stress of 42 °c, these differences increased to 23-fold. a turnover to ...201121338436
investigation of the genetic diversity of an invasive whitefly (bemisia tabaci) in china using both mitochondrial and nuclear dna markers.it is often considered that reduced genetic variation due to bottlenecks and founder effects limits the capacity for species to establish in new environments and subsequently spread. the recent invasion (during the past five years) of an alien whitefly, one member of bemisia tabaci cryptic species complex, referred to as mediterranean (herein referred to as q-type) in shandong province, china, provides an ideal opportunity to study the changes in genetic variation between its home range in the m ...201121320364
induction effects of host plants on insecticide susceptibility and detoxification enzymes of bemisia tabaci (hemiptera: aleyrodidae).the polyphagous b-biotype bemisia tabaci (gennadius) has developed a high resistance to commonly used insecticides in china. to illustrate the induced changes by host plant, bioassay and biochemical research on five different host populations were investigated.201121162148
influence of trichomes on attractiveness and ovipositional preference of bemisia tabaci (genn.) b biotype (hemiptera: aleyrodidae) on tomato genotypes.brazil is one of the world's largest tomato producer, but considerable part of the production is lost due to the attack of bemisia tabaci (genn.) b biotype. resistant germoplasm plants can be an important method for b. tabaci control in integrated pest management approaches. the attractiveness and ovipositional preference of b. tabaci for 17 tomato genotypes were evaluated in a free-choice test. trials were set up in a randomized block design with ten replicates. each replicate (one tomato plant ...201121271071
bemisia tabaci: a statement of species status.bemisia tabaci has long been considered a complex species. it rose to global prominence in the 1980s owing to the global invasion by the commonly named b biotype. since then, the concomitant eruption of a group of plant viruses known as begomoviruses has created considerable management problems in many countries. however, an enduring set of questions remains: is b. tabaci a complex species or a species complex, what are bemisia biotypes, and how did all the genetic variability arise? this review ...201120690829
tomato-produced 7-epizingiberene and r-curcumene act as repellents to whiteflies.how whiteflies (bemisia tabaci) make the choice for a host plant prior to landing, is not precisely known. here we investigated whether they respond to specific volatiles of tomato. zingiberene and curcumene were purified from solanum habrochaites (pi127826), characterised by nmr and x-ray analysis and identified as 7-epizingiberene and r-curcumene. in contrast, oil from zingiber officinalis contained the stereoisomers zingiberene and s-curcumene, respectively. using a combination of free-choice ...201121074818
development of a low-density dna microarray for diagnosis of target-site mutations of pyrethroid and organophosphate resistance mutations in the whitefly bemisia tabaci.rapid and accurate detection of mutations related to insecticide resistance is essential for development of resistance management strategies to support sustainable agriculture. the m918v, l925i and t929v mutations of the voltage-gated sodium channel gene (vgsc) and the f392w mutation of the acetylcholinesterase i gene (ace1) are reportedly associated with resistance to pyrethroids and organophosphates, respectively, in bemisia tabaci. in order to detect known base substitutions in the ace1 and v ...201121710552
[population genetic structure of bemisia tabaci (hemiptera: aleyrodidae) utilizing microsatellite markers].we aimed to characterize the population genetic structure within and among five bemisia tabaci (gennadius) populations collected from different host plants and geographic regions by using microssatelites as a molecular marker. each population was represented by 19 specimens. the host plants and geographic origins of these populations were described as follows: pop 1: squash barreiras (ba); pop 2: cotton barreiras (ba); pop 3: soybean campinas (sp); pop 4: tomato cruz das almas (ba); and pop 5: s ...201121584401
emerging virus diseases transmitted by whiteflies.virus diseases that have emerged in the past two decades limit the production of important vegetable crops in tropical, subtropical, and temperate regions worldwide, and many of the causal viruses are transmitted by whiteflies (order hemiptera, family aleyrodidae). most of these whitefly-transmitted viruses are begomoviruses (family geminiviridae), although whiteflies are also vectors of criniviruses, ipomoviruses, torradoviruses, and some carlaviruses. factors driving the emergence and establis ...201121568700
exploring the diversity of plant dna viruses and their satellites using vector-enabled metagenomics on whiteflies.current knowledge of plant virus diversity is biased towards agents of visible and economically important diseases. less is known about viruses that have not caused major diseases in crops, or viruses from native vegetation, which are a reservoir of biodiversity that can contribute to viral emergence. discovery of these plant viruses is hindered by the traditional approach of sampling individual symptomatic plants. since many damaging plant viruses are transmitted by insect vectors, we have deve ...201121544196
host plant effects on alkaline phosphatase activity in the whiteflies, bemisia tabaci biotype b and trialeurodes vaporariorum.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 phytophag ...201121521136
field trial measuring the compatibility of methoxyfenozide and flonicamid with orius laevigatus fieber (hemiptera: anthocoridae) and amblyseius swirskii (athias-henriot) (acari: phytoseiidae) in a commercial pepper greenhouse.frankliniella occidentalis (pergande) (thysanoptera: thripidae) and bemisia tabaci (gennadius) (hemiptera: aleyrodidae) are among the most serious pests of sweet peppers in greenhouses. chemical control is difficult because of their high reproductive rates and insecticide resistance, and seasonal inoculative releases of orius laevigatus (fieber) and amblyseius swirskii (athias-henriot) are commonly used to reduce their populations. as chemical treatments are often needed in the crop against othe ...201121495158
using double-stranded rna to explore the role of heat shock protein genes in heat tolerance in bemisia tabaci (gennadius).the whitefly, bemisia tabaci (gennadius) (homoptera: aleyrodidae) biotype b, is one of the most destructive invasive pests of field and glasshouse crops, and has a high tolerance to heat. our previous work found that whitefly females are more heat tolerant than males. in the present study, real-time pcr and double-stranded rna (dsrna) methods were used to explore the role of heat shock protein (hsp) genes in whitefly of both sexes; this provided further evidence of the mechanism underlying the d ...201121307062
an extensive field survey combined with a phylogenetic analysis reveals rapid and widespread invasion of two alien whiteflies in china.to understand the processes of invasions by alien insects is a pre-requisite for improving management. the whitefly bemisia tabaci is a cryptic species complex that contains some of the most invasive pests worldwide. however, extensive field data to show the geographic distribution of the members of this species complex as well as the invasion by some of its members are scarce.201121283707
identification and characterization of functional aquaporin water channel protein from alimentary tract of whitefly, bemisia tabaci.some hemipteran xylem and phloem-feeding insects have evolved specialized alimentary structures or filter chambers that rapidly transport water for excretion or osmoregulation. in the whitefly, bemisia tabaci, mass movement of water through opposing alimentary tract tissues within the filter chamber is likely facilitated by an aquaporin protein. b. tabaci aquaporin-1 (btaqp1) possesses characteristic aquaporin topology and conserved pore-forming residues found in water-specific aquaporins. as pr ...201121146609
further spread of and domination by bemisia tabaci (hemiptera: aleyrodidae) biotype q on field crops in china.the sweetpotato whitefly, bemisia tabaci (gennadius) (hemiptera: aleyrodidae), causes severe crop losses to many crops. the worst of these losses are often associated with the invasion and establishment of biotypes b and q of this pest. previous research in 2007 showed that biotype q occurred with other biotypes in most field populations in china. to determine the current status of the biotype composition in the field, an extensive survey covering mainly eastern parts of china was conducted in 2 ...201121735919
sublethal effects of imidacloprid on bemisia tabaci (hemiptera: aleyrodidae) under laboratory conditions.the sweetpotato whitefly, bemisia tabaci (gennadius) (hemiptera: aleyrodidae), is one of the most important pests in tropical and subtropical agriculture and is a key pest in greenhouse production worldwide. current management of b. tabaci relies upon frequent applications of insecticides. insecticide use not only directly affects pest populations through acute toxicity but also has indirect (sublethal) effects on pest physiology or behavior. in this study, we described sublethal effects of imid ...201121735901
effectiveness of thiamethoxam and imidacloprid seed treatments against bemisia tabaci (hemiptera: aleyrodidae) on cotton.bemisia tabaci (gennadius) biotype b is one of the most important pests on cotton around the world. laboratory, greenhouse and field experiments were conducted to determine the efficacy of thiamethoxam and imidacloprid seed treatments against b. tabaci on cotton.201121077123
reproductive incompatibility between the b and q biotypes of the whitefly bemisia tabaci in china: genetic and behavioural evidence.the b and q 'biotypes' of bemisia tabaci (gennadius) (hemiptera: aleyrodidae) have been invading many parts of the world and causing severe damage to a range of crops. recent phylogenetic analyses indicate that b and q are cryptic species within the b. tabaci species complex. although various attempts have been made to examine the reproductive compatibility between b and q, few studies have tested the fertility of the f1 females and so the extent of possible gene flow remains unclear. in this st ...201121034521
transcriptome analysis and comparison reveal divergence between two invasive whitefly cryptic species.invasive species are valuable model systems for examining the evolutionary processes and molecular mechanisms associated with their specific characteristics by comparison with closely related species. over the past 20 years, two species of the whitefly bemisia tabaci species complex, middle east-asia minor 1 (meam1) and mediterranean (med), have both spread from their origin middle east/mediterranean to many countries despite their apparent differences in many life history parameters. previously ...201121939539
chemical composition and insecticidal activity of essential oils of two aromatic plants from ivory coast against bemisia tabaci g. (hemiptera: aleyrodidae).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: ...201121922931
populations of predators and parasitoids of bemisia tabaci (hemiptera: aleyrodidae) after the application of eight biorational insecticides in vegetable crops.the sweetpotato whitefly, bemisia tabaci (gennadius) (hemiptera: aleyrodidae), is an important pest of vegetables and many other crops worldwide. eight biorational insecticides (based on oil, plant derivatives, insect growth regulator and fungus) were evaluated in the field for their influence on populations of six natural enemies of b. tabaci. natural populations of two predators [chrysoperla carnea stephen (neuroptera: chrysopidae) and orius spp. (hemiptera: anthocoridae)] and two genera of pa ...201121480463
rna interference for the control of whiteflies (bemisia tabaci) by oral route.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, alpha-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. eac ...201121451256
resistance of soybean genotypes to bemisia tabaci (genn.) biotype b (hemiptera: aleyrodidae).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 ...201121437493
extensive settlement of the invasive meam1 population of bemisia tabaci (hemiptera: aleyrodidae) in the caribbean and rare detection of indigenous populations.bemisia tabaci populations belonging to middle east-asia minor one (meam1) and mediterranean (med) groups (formerly biotype b and q, respectively) have spread throughout the world. although the introduction of meam1 is documented from several caribbean islands, it is generally not known whether med has also been introduced; whether indigenous populations have survived; and if in the affirmative, to which group(s) they belonged. whiteflies were collected from seven islands on various plant specie ...201122251711
rapid cold hardening and expression of heat shock protein genes in the b-biotype bemisia tabaci.this paper describes the rapid cold hardening processes of the sweetpotato whitefly, bemisia tabaci (gennadius). it was found that all developmental stages of b. tabaci have the capacity of rapid cold hardening and the length of time required to induce maximal cold hardiness at 0 °c varies with stage. there was only 18.3% survival when adult whiteflies were transferred directly from 26 °c to -8.5 °c for 2 h. however, exposure to 0 °c for 1 h before transfer to -8.5 °c increased the survival to 8 ...201122182622
genetic networking of the bemisia tabaci cryptic species complex reveals pattern of biological invasions.a challenge within the context of cryptic species is the delimitation of individual species within the complex. statistical parsimony network analytics offers the opportunity to explore limits in situations where there are insufficient species-specific morphological characters to separate taxa. the results also enable us to explore the spread in taxa that have invaded globally.201121998669
mtdna variability in whitefly (bemisia tabaci) populations in brazil.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 quantifie ...201121968683
characterization of cucumber vein-clearing virus, a whitefly (bemisia tabaci g.)-transmitted carlavirus. 201121956832
preliminary studies of effectiveness and selectivity of movento on bemisia tabaci and its parasitoid eretmocerus mundus.the bemisia tabaci gennadius (homoptera:aleyrodidae) biotype complex is a key pest of several worldwide crops. the management and control of this pest has become difficult mainly due to its high reproductive rate and capacity to develop resistance to broad spectrum insecticides. in argentina b. tabaci whitefly, causes economic losses in most areas of agricultural production. eretmocerus mundus mercet (hymenoptera:aphelinidae) is the most important parasitoid of b. tabaci and is commercialized as ...201223885443
rapid genetic turnover in populations of the insect pest bemisia tabaci middle east: asia minor 1 in an agricultural landscape.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 be ...201222420748
diversity and phylogenetic analysis of endosymbiotic bacteria from field caught bemisia tabaci from different locations of north india based on 16s rdna library screening.bemisia tabaci is the major vector pest of agricultural crops all over the world. in this study we report the different bacterial endosymbionts associated with b. tabaci sampled from 14 different locations in north india. using 16s rdna clone library sequences we were able to identify portiera, the primary endosymbiont of b. tabaci, and other secondary endosymbionts like cardinium, wolbachia, rickettsia and arsenophonus. along with these we also detected bacillus, enterobacter, paracoccus and ac ...201222293464
loop-mediated isothermal amplification for rapid identification of biotypes b and q of the globally invasive pest bemisia tabaci, and studying population dynamics.bemisia tabaci, the sweetpotato whitefly, is a globally invasive pest that causes serious agricultural damage by transmitting plant viruses. this pest forms a cryptic species complex that displays morphologically indistinguishable biotypes. among them, the b and q biotypes are the most important pests worldwide. because they have different levels of insecticide resistance, these biotypes must be identified in order to achieve proper pest control. therefore, a convenient, rapid and specific detec ...201222566408
[development of insecticide resistance and its effect factors in field population of bemisia tabaci in fujian province, east china].abstract: the development of insecticide resistance in field populations of bemisia tabaci from different regions of fujian province, china were monitored with adult leaf-dipping bioassay. compared with bioassay data of 2005, all field populations tested in 2009 still had high levels of resistance to the lambda-cyhalothrin, fenpropathrin and chlorpyrifos, low levels of resistance to methomyl, and no resistance to abamectin. however, resistance to the neonicotinoids imidacloprid and thiamethoxam ...201222489509
population genetic structure and secondary endosymbionts of q bemisia tabaci (hemiptera: aleyrodidae) from greece.we investigated the molecular diversity of the major agricultural pest bemisia tabaci and of its associated secondary endosymbionts in greece. analyzing mitochondrial dna, we found that the q1 (=q west) is predominant. we used eight microsatellite polymorphic markers to study the genetic structure of 37 populations from mainland and insular greece, collected on different host species from outdoor and protected crops as well as from non-cultivated plants. in some cases, gene flow was found to be ...201222280837
species delimitation and global biosecurity.species delimitation directly impacts on global biosecurity. it is a critical element in the decisions made by national governments in regard to the flow of trade and to the biosecurity measures imposed to protect countries from the threat of invasive species. here we outline a novel approach to species delimitation, "tip to root", for two highly invasive insect pests, bemisia tabaci (sweetpotato whitefly) and lymantria dispar (asian gypsy moth). both species are of concern to biosecurity, but i ...201222267902
resistance mechanisms to chlorpyrifos and f392w mutation frequencies in the acetylcholine esterase ace1 allele of field populations of the tobacco whitefly, bemisia tabaci in china.the tobacco whitefly b-biotype bemisia tabaci gennadius (hemiptera: aleyrodidae) is a worldwide pest of many crops. in china, chlorpyrifos has been used to control this insect for many years and is still being used despite the fact that some resistance has been reported. to combat resistance and maintain good control efficiency of chlorpyrifos, it is essential to understand resistance mechanisms. a chlorpyrifos resistant tobacco whitefly strain (nj-r) and a susceptible strain (nj-s) were derived ...201222954331
lack of fitness costs associated with acetamiprid resistance in bemisia tabaci (hemiptera: aleyrodidae).sweetpotato whitefly, bemisia tabaci (gennadius) (hemiptera: aleyrodidae), is a devastating pest that can cause severe damage to a range of crops by direct feeding and by plant virus transmission. because of indiscriminate use of insecticides, this whitefly has developed resistance to several insecticides, including neonicotinoids. our objectives were to determine fitness components affected by acetamiprid resistance in b. tabaci. assay results showed that selection with acetamiprid had removed ...201222928322
shifting preference between oviposition vs. host-feeding under changing host densities in two aphelinid parasitoids.destructive host-feeding is common in hymenopteran parasitoids. such feeding may be restricted to host stages not preferred for oviposition. however, whether this is a fixed strategy or can vary according to resource levels or parasitoid needs is less clear. we tested the trade-off between host feeding and oviposition on two whitefly parasitoids under varying host densities. females of two aphelinid parasitoids, eretmocerus hayati and encarsia sophia were exposed to nine different densities of t ...201222815964
influence of plant combinations on population characteristics of bemisia tabaci biotypes b and q.in recent years, the dominant biotype of bemisia tabaci (gennadius) has shifted from biotype b to q in many locations of china. our field monitoring showed that b. tabaci biotype q could be found on pepper capsicum frutescens l. while biotype b could not be found on the plant. to study the role of the host plant in the displacement of biotype b by q, the adult mortality, female fecundity, and adult emergence of both biotypes b and q on different host combinations were studied using a model syste ...201222812132
are yellow sticky traps an effective method for control of sweetpotato whitefly, bemisia tabaci, in the greenhouse or field?yellow sticky traps are a common method for monitoring many pests, but it has not been shown whether they could be used as a control method. in this study the impact of yellow sticky traps on the population dynamics of the sweetpotato whitefly, bemisia tabaci (gennadius) (hemiptera: aleyrodidae) was determined in the greenhouse and field. in the greenhouse, yellow sticky traps significantly suppressed the population increase of adult and immature whiteflies. the whitefly densities in the greenho ...201223445077
[effects of the volatiles from different tomato varieties on host selection behavior of b-biotype bemisia tabaci].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 wh ...201223286009
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