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bemisia argentifolii is a race of b. tabaci (hemiptera: aleyrodidae): the molecular genetic differentiation of b. tabaci populations around the world.the phylogenetic relationships between genotypes of bemisia tabaci were compared using its1 and co1 nucleotide sequences. phylogenetic and minimum spanning network analyses identified six major races, asia, bali, australia, sub-saharan africa, mediterranean/asia minor/africa and new world as well as a large collection of genotypes from the asia region with no strong association with any of the races. the term race is based on its usage in mallet (2001). mating incompatibility occurs between some ...200515960874
[feeding behavior of serangium japonicum (coleoptera: coccinellidae), a predator of bemisia tabaci (homoptera: aleyrodidae)].serangiurm japonicum is an important predator of whiteflies in china. in this study, the bemisia tabaci-attacking behavior of s. japonicum adults and larvae was observed by a videocassette recorder. the results showed that the predatory behavior of s. japonicum adults was characteristic with six events, i.e., walking, feeding, clearing, resting, vibrating wings, and excreting. the starved larvae of s. japonicum was fond spending all times in feeding and walking on host eggs, with no time in rest ...200515943367
host-parasitoid interactions relating to penetration of the whitefly, bemisia tabaci, by the parasitoid wasp, eretmocerus mundus.it has been reported that the aphelinid wasp eertmocerus mundus parasitizes all four nymphal instars of the sweet potato whitefly, bemisia tabaci (biotype b), with 3rd instars being the preferred hosts. the parasitoid lays its egg on the leaf underneath the host nymph. first instars hatch and later penetrate the whitefly. previous studies have shown that the initiation of parasitoid penetration induces the host to form a cellular capsule around the parasitoid. as described here, females never ov ...200517119628
benzothiadiazole induces local resistance to bemisia tabaci (hemiptera: aleyrodidae) in tomato plants.plant resistance to the b and q biotypes of sweetpotato whitefly, bemisa tabaci (gennadius), induced by benzo [1,2,3] thiadiazole-7-carbothioic acid-s-methyl ester (bth or acibenzolar-s-methyl) in tomato 'marmande' plants was evaluated in free-choice and no-choice assays under different conditions. bth is the active ingredient of the syngenta plant activator bion. bth treatment affected host preference of b. tabaci (b and q biotypes) adults on plants sprayed with bion at 0.2 and 0.4 g/liter duri ...200516539159
[life table of natural bemisia tabaci population on cucumber plants in different seasons].the study showed that in the early growth stage of cucumber in spring, the predation on bemisia tabaci egg was the key factor for controlling b. tabaci population, and the exclusion index of population control was 1.7333. in the late growth stage of cucumber in spring, summer and autumn, the predation on b. tabaci elder nymph was the critical factor for controlling b. tabaci population, and the exclusion index of population control was 4.5372, 4.0429 and 7.9021, respectively. from spring to autu ...200516515210
response of the polyphagous whitefly bemisia tabaci b-biotype (hemiptera: aleyrodidae) to crop diversification - influence of multiple sensory stimuli on activity and fecundity.a fundamental question concerning crop diversification is which mechanisms determine pest population size in polycultures compared to monocultures. it has been proposed that polyphagous insects experience a difficulty in decision-making when selecting food and oviposition sites in the presence of different host plants. this hypothesis was tested in the extremely polyphagous whitefly bemisia tabaci (gennadius) b-biotype, where behaviour (movement) and fecundity of females were compared in choice ...200616441901
multiple origins of pyrethroid resistance in sympatric biotypes of bemisia tabaci (hemiptera: aleyrodidae).the two most damaging biotypes of bemisia tabaci, b and q, are sympatric in the mediterranean basin and show high resistance to pyrethroids synergized by organophosphates. previous work showed that in the b biotype, this resistance is associated with the l925i mutation in the para-type voltage gated sodium channel. here we identified two mutations in the para-type voltage gated sodium channel associated with resistance to pyrethroids synergized by organophosphates in the q biotype: the l925i mut ...200616360952
bemnisia tabaci feeding induces pathogenesis-related proteins in cassava (manihot esculenta crantz).cassava (manihot esculenta cranzts) plants fed upon by whitefly bemisia tabaci showed increased levels of pathogenesis-related (pr) proteins, such as beta-1, 3-glucanase, peroxidase and chitinase activities, as compared to uninfested plants. the enzymes increased in specific activities from 2 to 7 fold and protein content in leaf extracts decreased in whitefly-infested plants, compared to uninfested plants. among the three pr proteins, b. tabaci feeding induced significantly higher beta-1, 3-glu ...200616967908
modeling evolution of resistance to pyriproxyfen by the sweetpotato whitefly (homoptera: aleyrodidae).we used computer simulations to examine evolution of resistance to the insect growth regulator (igr) pyriproxyfen by the sweetpotato whitefly, bemisia tabaci (gennadius), biotype b [=bemisia argentifolii (bellows & perring)]. consistent with trends seen in cotton (gossipyium spp.) fields in arizona and israel, results suggest that evolution of resistance to pyriproxyfen may occur rapidly in this haplodiploid insect. similar to results from models of diploid insects, resistance evolved faster wit ...200616937698
feeding preference of macrolophus caliginosus (heteroptera: miridae) on bemisia tabaci and trialeurodes vaporariorum (homoptera: aleyrodidae).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, you ...200616937666
within-plant distribution and sampling of single and mixed infestations of bemisia tabaci and trialeurodes vaporariorum (homoptera: aleyrodidae) in winter tomato crops.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 provi ...200616686130
comparative study of the five biological parameters of cotton whitefly bemisia tabaci and silverleaf whitefly b. argentifolii bellows and perring reared on cotton under laboratory condition.the five biological parameters of sweetpotato whitefly, bemisia tabaci (genn.) and silverleaf whitefly bemisia argentifolii bellows and perring (hom: aleyrodidae) as an important pest of cotton were compared on cotton in laboratory condition. the infested leaves containing nymphs and pupae were collected from cotton fields in iran. experiments were conducted in a growth chamber under 24+/-2 degrees c, 55+/-3% rh and 16:8 (l:d) photoperiod on cotton, gossypium hirsutum l. the newly emerged popula ...200617385531
effect of zohar lq-215, a biorational surfactant, on the sweetpotato whitefly bemisia tabaci (biotype b).zohar lq-215, a surfactant based on plant oils, able to control nymphs of the whitefly, bemisia tabaci (gennadius), under laboratory and field conditions. to evaluate the effects of the surfactant on the nymph stages of whitefly under laboratory conditions, potted cotton seedlings infested with 1st- or 3rd-instars were treated with the compound aqueous solutions. lc90 values of zohar lq-215 on 1st and 3rd-nymphs, based on mortality curves, were 0.78% and 1.14%, respectively. adult mortality of 1 ...200617385496
[predation of axinoscymnus cardilobus to bemisia tabaci].the laboratory study on the predation of axinoscymnus cardilobus to bemisia tabaci showed that the functional response of a. cardilobus to b. tabaci was of holling' s type ii. with the increasing age of b. tabaci, the searching rate of a. cardilobus adult decreased, and its handling time became longer. the searching rate of a. cardilobus larva was increased with its age, and the handling time became shorter. the mutual interference in individual predator could be described by hassell and varley ...200617209395
buprofezin inhibits acetylcholinesterase activity in b-biotype bemisia tabaci.b-biotype bemisia tabaci is a severe insect pest worldwide in many ornamental, agricultural, and horticultural industries. control of this insect is hampered by resistance to many acetylcholinesterase (ache)-inhibiting insecticides, such as organophosphates and carbamates. consequently, insect growth regulators such as buprofezin, which act by inhibiting chitin synthesis, are being investigated for use against b-biotype b. tabaci in australia. this study discusses the effects of buprofezin on b. ...200617192620
effect of pretreatment with piperonyl butoxide on pyrethroid efficacy against insecticide-resistant helicoverpa armigera (lepidoptera: noctuidae) and bemisia tabaci (sternorrhyncha: aleyrodidae).pyrethroid resistance in b-type bemisia tabaci gennadius and australian helicoverpa armigera hübner field populations is primarily conferred by esterase isoenzymes which metabolise and sequester pyrethroid insecticides. it has been shown previously that pyrethroid resistance-associated esterases in h. armigera are inhibited by the insecticide synergist piperonyl butoxide (pbo) over a 22-h period. it is demonstrated here that similar inhibition can be obtained against b-type b. tabaci. small-scal ...200616235269
previous and present diets of mite predators affect antipredator behaviour of whitefly prey.predator diet is known to influence antipredator behaviour in prey. yet, it is not clear how antipredator behaviour is affected by diet changes of the predator. we studied the effect of previous and present diet of a predatory mite typhlodromips swirskii on the antipredator response of its prey, the whitefly bemisia tabaci. an earlier study showed that adult female whiteflies that had experienced predators, had learned to avoid ovipositing on plants with predators whose previous and present diet ...200616596346
heterologous expression of the mi-1.2 gene from tomato confers resistance against nematodes but not aphids in eggplant.the mi-1.2 gene in tomato (solanum lycopersicum) is a member of the nucleotide-binding leucine-rich repeat (nblrr) class of plant resistance genes, and confers resistance against root-knot nematodes (meloidogyne spp.), the potato aphid (macrosiphum euphorbiae), and the sweet potato whitefly (bemisia tabaci). mi-1.2 mediates a rapid local defensive response at the site of infection, although the signaling and defensive pathways required for resistance are largely unknown. in this study, eggplant ...200616610741
pathogenicity of fusarium semitectum against crop pests and its biosafety to non-target organisms.microbial control is receiving more attention, since these alternative tactics, compared to chemical control methods, are energy saving, non polluting, ecologically sound and sustainable. a mycopathogen, fusarium semitectum berk. and rav. (arsef 7233) was isolated from diseased cadavers of aphid (aphis gossypii) and cultured in saboraud maltose agar supplemented with yeast extract medium (smay). being isolated first time from the chilli ecosystem its potential was evaluated. experiments were con ...200617385514
detection by rapd-pcr of polymorphism in populations of bemisia tabaci (genn.) collected on four host plants from iran.the sweetpotato whitefly, bernisia tabaci (genn.) (hom: aleyrodidae) is a major pest of field crops, vegetables and ornamentals in iran. in this study, the infested leaves of cucumber (cucurnis sativus l.) zucchini (cucurbita pepo l.) eggplant (solanum melongena l.) and cotton (gossypium hirsutum l.) with whitefly nymphs and pupae were collected from iran, and were transferred to the laboratory. the newly emerged males and females of each population were released separately into a large cage set ...200617385530
typing of tomato yellow leaf curl viruses and their vector in italy.a molecular survey of tylcv/tylcsv and their associated vector bemisia tabaci, was performed during 2004-2005 in five regions of southern italy: i.e. sardinia (one locations), sicily (one location), calabria (three locations), campania (two locations) and basilicata (one location). a total of 71 tomato samples were checked for virus infection and for the presence of the vector. degenerate primers allowing the amplification of the coat protein gene of both tylcsv and tylcv isolates were designed. ...200617390884
integrated management of tylcv/tylcsv on greenhouse hydroponic tomatoes in southern italy.tomato yellow leaf curl (tylc) caused by tomato yellow leaf curl virus (tylcv) and tomato yellow leaf curl sardinia virus (tylcsv), vectored by the whitefly bemisia tabaci, is a major disease of tomato in sardinia and sicily, and is becoming a serious threat in southern italy too. tylcsv was first reported in calabria region in 1991, but apparently it was an occasional outbreak, and b. tabaci was not detected. later, during the 2003-2004 winter, a serious epidemic was observed in protected tomat ...200617390886
[spatial patterns of bemisia tabaci (gennadius) population in cotton fields].field investigations on the vertical and horizontal distribution patterns of bemisia tabaci (gennadius) population on bt cotton guokang no. 22 and non-bt cotton simian no. 3 showed that in july, no obvious difference was found in the vertical distribution of b. tabaci population on cotton plant, but in august, the population density was significantly higher on the upper part of cotton plant than on its middle and lower parts. the horizontal distribution patterns of b. tabaci adult and nymph were ...200617044499
effect of cotton cultivar on performance of aphis gossypii (homoptera: aphididae) in iran.cotton aphids, aphis gossypii glover (homoptera: aphididae), obtained from cotton, gossypium hirsutum l., fields in the gorgan region of northern iran, were colonized on 'varamin' cotton plants in a growth chamber. the development, survivorship, and life table parameters of the cotton aphid were evaluated at 27.5 +/- 1 degrees c, 65 +/- 10% rh, and aphotoperiod of 14:10 (l:d) h of artificial light on five commonly growing cotton cultivars: varamin, 'sealand' (relatively resistant cultivar), 'bak ...200617066818
identification and localization of a rickettsia sp. in bemisia tabaci (homoptera: aleyrodidae).whiteflies (homoptera: aleyrodidae) are sap-sucking insects that harbor "candidatus portiera aleyrodidarum," an obligatory symbiotic bacterium which is housed in a special organ called the bacteriome. these insects are also home for a diverse facultative microbial community which may include hamiltonella, arsenophonus, fritchea, wolbachia, and cardinium spp. in this study, the bacteria associated with a b biotype of the sweet potato whitefly bemisia tabaci were characterized using molecular fing ...200616672513
microsatellites reveal extensive geographical, ecological and genetic contacts between invasive and indigenous whitefly biotypes in an insular environment.human-mediated bioinvasions provide the opportunity to study the early stages of contact between formerly allopatric, divergent populations of a species. however, when invasive and resident populations are morphologically similar, it may be very difficult to assess their distribution in the field, as well as the extent of ecological overlap and genetic exchanges between invasive and resident populations. we here illustrate the use of data obtained from a set of eight microsatellite markers toget ...200616709274
bemisia tabaci transmission of specific lettuce infectious yellows virus genotypes derived from in vitro synthesized transcript-inoculated protoplasts.bemisia tabaci transmission was demonstrated for virions derived from cloned infectious cdnas of lettuce infectious yellows virus (liyv). rna transcripts synthesized from the cdna clone of liyv rna 1 and for clones of seven genotypes (pr6, p1-1a, p1-2b, p1-2f, p1-4h, p1-5b, and p1-5d) of liyv rna 2 produced virions or virion-like particles (vlps) when inoculated to tobacco protoplasts. pr6, p1-1a, and p1-2f virions were transmissible to plants by b. tabaci and transmission frequencies ranged fro ...200616750548
mi-1-mediated aphid resistance involves salicylic acid and mitogen-activated protein kinase signaling cascades.the tomato mi-1 gene confers resistance to root-knot nematodes (meloidogyne spp.), potato aphids (macrosiphum eluphorbiae), and whiteflies (bemisia tabaci and b. tabaci biotype b). resistance to potato aphid is developmentally regulated and is not associated with induction of a hypersensitive response. the nahg transgene that eliminates endogenous salicylic acid (sa) was used to test the role of the sa signaling pathway in the resistance mediated by mi-1 to potato aphids. aphids survived longer ...200616776299
post-transcriptional gene silencing in controlling viruses of the tomato yellow leaf curl virus complex.tomato yellow leaf curl disease (tylcd) is caused by a group of geminiviruses that belong to the tomato yellow leaf curl virus (tylcv) complex and are transmitted by the whitefly (bemisia tabaci genn.). the disease causes great yield losses in many countries throughout the mediterranean region and the middle east. in this study, the efficacy of post-transcriptional gene silencing (ptgs) to control the disease caused by tylcv complex was investigated. non-coding conserved regions from the genome ...200616862387
effectiveness of two insect growth regulators against bemisia tabaci (gennadius) (homoptera: aleyrodidae) and helicoverpa armigera (hübner) (lepidoptera: noctuidae) and their impact on population densities of arthropod predators in cotton in pakistan.field efficacies of two insect growth regulators (igrs) at two recommended application rates, buprofezin at 370 and 555 g ai ha(-1) and lufenuron at 37 and 49 g ai ha(-1), were determined against the sweet potato whitefly, bemisia tabaci (gennadius), and the cotton bollworm, helicoverpa armigera (hübner), in experimental plots of cotton at the directorate of cotton research, faisalabad, pakistan. adverse effects of the igrs on populations of associated arthropod predators, namely geocorids, chry ...200616862616
closely related wolbachia strains within the pumpkin arthropod community and the potential for horizontal transmission via the plant.phylogenetic studies have implicated frequent horizontal transmission of wolbachia among arthropod host lineages. however, the ecological routes for such lateral transfer are poorly known. we surveyed the species of two arthropod communities, one on pumpkin and the other on loofah plants, for wolbachia, constructed wsp gene phylogenies of those wolbachia strains found to infect community members, and established ecological links among infected members. four taxonomically diverse insects in the p ...200616598632
whitefly (bemisia tabaci) genome project: analysis of sequenced clones from egg, instar, and adult (viruliferous and non-viruliferous) cdna libraries.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 geno ...200616608516
sublethal effects of beauveria bassiana (balsamo) vuillemin (deuteromycotina: hyphomycetes) on the whitefly bemisia tabaci (gennadius) (hemiptera: aleyrodidae) under laboratory conditions.sublethal effects were evaluated in subsequent generations of whiteflies bemisia tabaci (gennadius) arising from parental generations exposed in the four nymphal stages to the fungus beauveria bassiana (balsamo) vuillemin. examples of such effects include impaired fertility, production of malformations or external variations, and reduced survival of later generations. malformations of the head, legs, wings or abdomen were not observed in adults derived from treated nymphs, nor were negative effe ...200617146585
vector-virus mutualism accelerates population increase of an invasive whitefly.the relationships between plant viruses, their herbivore vectors and host plants can be beneficial, neutral, or antagonistic, depending on the species involved. this variation in relationships may affect the process of biological invasion and the displacement of indigenous species by invaders when the invasive and indigenous organisms occur with niche overlap but differ in the interactions. the notorious invasive b biotype of the whitefly complex bemisia tabaci entered china in the late 1990s an ...200717264884
purification and characterization of recombinant ligand-binding domains from the ecdysone receptors of four pest insects.cloned ecr and usp cdnas encoding the ecdysone receptors of four insect pests (lucilia cuprina, myzus persicae, bemisia tabaci, helicoverpa armigera) were manipulated to allow the co-expression of their ligand binding domains (lbds) in insect cells using a baculovirus vector. recombinant de/f segment pairs (and additionally, for h. armigera, an e/f segment pair) from the ecr and usp proteins associated spontaneously with high affinity to form heterodimers that avidly bound an ecdysteroid ligand. ...200717275327
biotype status and genetic polymorphism of the whitefly bemisia tabaci (hemiptera: aleyrodidae) in greece: mitochondrial dna and microsatellites.the genetic polymorphism and the biotype identity of the tobacco whitefly bemisia tabaci (gennadius) have been studied in population samples taken from different localities within greece from cultivated plants growing in greenhouses or in open environments and from non-cultivated plants. two different approaches were used: sequencing of the mitochondrial cytochrome oxidase i (mtcoi) gene and genotyping using microsatellite markers. analyses of the mtcoi sequences revealed a high homogeneity betw ...200717298679
making a friend from a foe: expressing a groel gene from the whitefly bemisia tabaci in the phloem of tomato plants confers resistance to tomato yellow leaf curl virus.some (perhaps all) plant viruses transmitted in a circulative manner by their insect vectors avoid destruction in the haemolymph by interacting with groel homologues, ensuring transmission. we have previously shown that the phloem-limited begomovirus tomato yellow leaf curl virus (tylcv) interacts in vivo and in vitro with groel produced by the whitefly vector bemisia tabaci. in this study, we have exploited this phenomenon to generate transgenic tomato plants expressing the whitefly groel in th ...200717334947
the mi-1-mediated pest resistance requires hsp90 and sgt1.the tomato (solanum lycopersicum) mi-1 gene encodes a protein with putative coiled-coil nucleotide-binding site and leucine-rich repeat motifs. mi-1 confers resistance to root-knot nematodes (meloidogyne spp.), potato aphids (macrosiphum euphorbiae), and sweet potato whitefly (bemisia tabaci). to identify genes required in the mi-1-mediated resistance to nematodes and aphids, we used tobacco rattle virus (trv)-based virus-induced gene silencing (vigs) to repress candidate genes and assay for nem ...200717351050
a multiplex pcr method discriminating between the tylcv and tylcv-mld clades of tomato yellow leaf curl virus.tomato yellow leaf curl virus (tylcv) is one of the causal agents of tomato yellow leaf curl disease (tylcd) and can cause up to 100% yield losses in tomato fields. as tylcv continues to spread, many isolates have been described in different parts of the world. recently two closely related but distinct tylcv clades, called tylcv and tylcv-mld, have been identified. isolates from those two clades differ mainly in the nucleotide sequences of their replication associated protein genes but do not di ...200717485124
prevalence of wolbachia infection in bemisia tabaci.wolbachia are obligate intracellular bacteria present in reproductive tissues of many arthropod species. it has been reported that few silverleafing populations of bemisia tabaci were positive for wolbachia, whereas non-silverleafing populations were more likely infected with wolbachia and all that infect b. tabaci are wolbachia belonging to supergroup b. however, current detection methods were shown to be not sensitive enough to uncover all infections. herein, a protocol based on polymerase cha ...200717487529
ligand binding by recombinant domains from insect ecdysone receptors.the ligand binding domains (lbds) from the ecr and usp proteins of four insect pests (lucilia cuprina, myzus persicae, bemisia tabaci, helicoverpa armigera) were purified as recombinant heterodimers. the k(d) values for [(3)h]-ponasterone a binding by lbd heterodimers that included the hinge regions (i.e., de/f heterodimers) ranged 0.7-2.5 nm, with k(i) values for ecdysteroid and dibenzoylhydrazine ligands ranging from 0.1 nm to >448 microm. the k(d) and k(i) values for a recombinant h. armigera ...200717517338
rnai-mediated resistance to bean golden mosaic virus in genetically engineered common bean (phaseolus vulgaris).bean golden mosaic virus (bgmv) is transmitted by the whitefly bemisia tabaci in a persistent, circulative manner, causing the golden mosaic of common bean (phaseolus vulgaris l.). the characteristic symptoms are yellow-green mosaic of leaves, stunted growth, or distorted pods. the disease is the largest constraint to bean production in latin america and causes severe yield losses (40 to 100%). here, we explored the concept of using an rna interference construct to silence the sequence region of ...200717555279
development of real-time rt-pcr assays for the detection of cucumber vein yellowing virus (cvyv) and cucurbit yellow stunting disorder virus (cysdv) in the whitefly vector bemisia tabaci.reverse transcription followed by real-time pcr assays based on taqman chemistry have been developed for the detection and quantification of cucumber vein yellowing virus (cvyv) and cucurbit yellow stunting disorder virus (cysdv) in individual adults of the whitefly vector bemisia tabaci. the method includes an internal control for the detection of a gene from b. tabaci to compensate for variations in extraction efficiency. the assays designed were used to estimate proportions of viruliferous wh ...200717624449
biotype-dependent secondary symbiont communities in sympatric populations of bemisia tabaci.the sweet potato 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. bemisia tabaci is a species complex composed of numerous biotypes, which may differ from each other both genetically and biologically. only the b and q biotypes have been reported from israel. secondary symbiont infection frequenci ...200717645822
toxicity of seven foliar insecticides to four insect parasitoids attacking citrus and cotton pests.laboratory studies were carried out to compare the toxicity of seven foliar insecticides to four species of adult beneficial insects representing two families of hymenoptera: aphelinidae (aphytis melinus debach, eretmocerus eremicus rose & zolnerowich, and encarsiaformosa gahan) and mymaridae (gonatocerus ashmeadi girault) that attack california red scale, aonidiella aurantii (maskell); sweetpotato whitefly, bemisia tabaci (gennadius) (both e. eremicus and e. formosa); and glassy-winged sharpsho ...200717849851
effects of proportion and configuration of bacillus thuringiensis cotton on pest abundance, damage, and yield.bacillus thuringiensis (bt) transgenic cotton, gossypium hirsutum l., kills several economically important pests, reducing injury and increasing yields. refuges of non-bt cotton are currently planted with bt cotton in different designs to slow pest resistance evolution. to compare the effects of differences in bt/non-bt plant heterogeneity found in different refuge designs on square (flower bud) damage, abscissions, sap-feeding herbivore densities, and yield in cotton, four types of 24-row cotto ...200717849898
pcr-based detection and partial genome sequencing indicate high genetic diversity in bangladeshi begomoviruses and their whitefly vector, bemisia tabaci.the population diversity of bangladeshi begomoviruses and their vector, bemisia tabaci was analysed by pcr-based detection and partial genome sequencing. b. tabaci adults and plants expressing symptoms of virus infection were collected from locations representing diverse agro-ecological regions of the country. universal and species-specific primers were used to detect begomoviruses in seven crops (chilli, okra, papaya, pumpkin, sponge gourd, tomato and yardlong bean) and two common weeds (agerat ...200716927121
expression of stress-response proteins upon whitefly-mediated inoculation of tomato yellow leaf curl virus in susceptible and resistant tomato plants.to better understand the nature of resistance of tomato to the whitefly (bemisia tabaci, b biotype)-transmitted tomato yellow leaf curl virus (tylcv), whiteflies and tylcv were considered as particular cases of biotic stresses and virus resistance as a particular case of successful response to these stresses. two inbred tomato lines issued from the same breeding program that used solanum habrochaites as a tylcv resistance source, one susceptible and the other resistant, were used to compare the ...200717977149
asymmetric mating interactions drive widespread invasion and displacement in a whitefly.the role of behavioral mechanisms in animal invasions is poorly understood. we show that asymmetric mating interactions between closely related but previously allopatric genetic groups of the whitefly bemisia tabaci, a haplodiploid species, have been a driving force contributing to widespread invasion and displacement by alien populations. we conducted long-term field surveys, caged population experiments, and detailed behavioral observations in zhejiang, china, and queensland, australia, to inv ...200717991828
three years survey of tomato yellow leaf curl sardinia virus reservoir weed hosts in southern italy.during the period from august 2004 to june 2006 a serious tomato yellow leaf curl epidemic caused by both tomato yellow leaf curl sardinia virus (tylcsv) and tomato yellow leaf curl virus (tylcs) was observed in protected tomato crops in castrovillari, calabria region, in a group of greenhouses where tomato is grown hydroponically. a three years survey for reservoir weed hosts of these viruses was performed during summer period in order to identify where the viruses persist during the host-free ...200718396845
relationship between tomato yellow leaf curl viruses and the whitefly vector.tomato yellow leaf curl virus (tylcv) and tomato leaf curl virus (tolcv) are the currently known begomoviruses in uganda. the relationship with their whiteflies (bemisia tabaci) vector and its management were not known in uganda. a direct relationship was expected between these begomoviruses and whiteflies at buwama in mpigi district of uganda. farmer practices were expected to have limited efficacy. to investigate this, a completely randomised block design was used for all trials with six treat ...200718396846
an approach for ipm program to control sucking pests infesting garden bean plants (phaseolus vulgaris l.) in egypt.an approach to eatablish ipm program for some sucking pests infesting garden beans plants was carried out in two successive seasons of 2004 and 2005 under field conditions in alexandria, egypt. the sucking pests included the aphid, aphis craccivora koch (homoptera: aphididae), the white fly, bemisia tabaci genn. (homoptera: aleyroidae) and the spider mite, tetranychus urticae koch pymetrozine, thiamethoxam, carbosulfan, abamectin, azadirachtin and the detergent (masrol 410) were tested for their ...200718399490
a recessive allele (tgr-1) conditioning tomato resistance to geminivirus infection is associated with impaired viral movement.abstract begomoviruses (the family geminiviridae) are transmitted by the whitefly bemisia tabaci and contain monopartite or bipartite circular single-stranded (ss)dna genomes. they have emerged as severe problems in the production of agricultural and horticultural crops worldwide. here, we report the identification of a tomato breeding line, fla653, that confers a high level of resistance to tomato leaf curl virus (tlcv, monopartite). genetic analysis indicated that the resistance is controlled ...200718943632
biotype status and distribution of bemisia tabaci (hemiptera: aleyrodidae) in shandong province of china based on mitochondrial dna markers.bemisia tabaci has caused significant crop losses in china during the last decade. recent research has shown that two potentially invasive variants, biotypes b and q, have been found in several regions of china. our objective was to determine the biotype status and the distribution of b. tabaci in shandong province, an important agricultural region of china. based on mitochondrial dna markers, both biotypes b and q were detected, with b being the predominant biotype. the results indicate that th ...200718284755
identification and characterization of a novel whitefly-transmitted member of the family potyviridae isolated from cucurbits in florida.abstract a novel whitefly-transmitted member of the family potyviridae was isolated from a squash plant (cucurbita pepo) with vein yellowing symptoms in florida. the virus, for which the name squash vein yellowing virus (sqvyv) is proposed, has flexuous rod-shaped particles of approximately 840 nm in length. the experimental host range was limited to species in the family cucurbitaceae, with the most dramatic symptoms observed in squash and watermelon, but excluded all tested species in the fami ...200718944369
legume yellow mosaic viruses: genetically isolated begomoviruses.summary: the yellow mosaic diseases of a number of legumes across southern asia are caused by four species of whitefly-transmitted geminiviruses (genus begomovirus, family geminiviridae): mungbean yellow mosaic virus, mungbean yellow mosaic india virus, dolichos yellow mosaic virus and horsegram yellow mosaic virus. they cause losses to a number of important pulse crops, a major source of dietary protein in the region. the viruses have host ranges limited to plants of the family fabaceae and eff ...200720507504
prey species preference of the predator serangium parcesetosum sicard (col., coccinellidae) and its interaction with another natural enemy.this study aimed to determine serangium parcesetosum preference for different prey species and parasitized bemisia tabaci (genn.) (hom., aleyrodidae) by the parasitoid, eretmocerus mundus mercet (hym., aphelinidae). the results on s. parcesetosum preference by feeding on different prey species offered separately and together indicated that the predatory larvae and adults preferred significantly the cotton whitefly, b. tabaci and the castor bean whitefly, trialeurodes ricini (misra) (hom., aleyro ...200719070175
thermal effect on the biology and life tables of bemisia tabaci gennadius (homoptera: aleyrodidae).the life history and life table of bemisia tabaci gennadius on cucumber was studied under laboratory conditions at 20, 25 and 30 degrees c. the overall developmental time varied from 34.8 days at 20 degrees c to 14.1 days at 30 degrees c. immature mortality decreased from 45.8 to 17.3% with increasing temperature. the threshold temperatures of egg, 1st, 2nd, 3rd and 4th nymphal stage and a generation were 14.72, 14.36, 10.18, 11.40, 14.36 and 13.07 degrees c whereas the degree-day requirement at ...200719090279
arabidopsis transcriptome changes in response to phloem-feeding silverleaf whitefly nymphs. similarities and distinctions in responses to aphids.phloem-feeding pests cause extensive crop damage throughout the world, yet little is understood about how plants perceive and defend themselves from these threats. the silverleaf whitefly (slwf; bemisia tabaci type b) is a good model for studying phloem-feeding insect-plant interactions, as slwf nymphs cause little wounding and have a long, continuous interaction with the plant. using the affymetrix ath1 genechip to monitor the arabidopsis (arabidopsis thaliana) transcriptome, 700 transcripts we ...200717189325
silverleaf whitefly induces salicylic acid defenses and suppresses effectual jasmonic acid defenses.the basal defenses important in curtailing the development of the phloem-feeding silverleaf whitefly (bemisia tabaci type b; slwf) on arabidopsis (arabidopsis thaliana) were investigated. sentinel defense gene rnas were monitored in slwf-infested and control plants. salicylic acid (sa)-responsive gene transcripts accumulated locally (pr1, bgl2, pr5, sid2, eds5, pad4) and systemically (pr1, bgl2, pr5) during slwf nymph feeding. in contrast, jasmonic acid (ja)- and ethylene-dependent rnas (pdf1.2, ...200717189328
temporal synergism by microencapsulation of piperonyl butoxide and alpha-cypermethrin overcomes insecticide resistance in crop pests.a microencapsulated formulation that gives a burst release of piperonyl butoxide (pbo) several hours before a burst release of a conventional pyrethroid can effectively overcome metabolic resistance in bemisia tabaci gennadius, helicoverpa armigera (hübner), aphis gossypii glover and myzus persicae sulzer. this increase in efficacy against resistant pests was reflected in a field trial against b. tabaci on cotton, eliminating the need for two treatments. the ratio between the active insecticide ...200717304634
critical feeding periods for last instar nymphal and pharate adults of the whiteflies, trialeurodes vaporariorum and bemisia tabaci.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 ...200720302459
effects of host plants on insecticide susceptibility and carboxylesterase activity in bemisia tabaci biotype b and greenhouse whitefly, trialeurodes vaporariorum.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. vapo ...200717323411
toxicity and feeding deterrence of crude toxin extracts of lecanicillium (verticillium) lecanii (hyphomycetes) against sweet potato whitefly, bemisia tabaci (homoptera: aleyrodidae).crude toxins [toxin(v3450) and toxin(vp28,) extracted from lecanicillium (verticillium) lecanii (zimmermann) gams & zare strain v3450 and vp28 respectively] were tested for contact toxicity, feeding deterrence and repellent activity against the sweet potato whitefly, bemisia tabaci (gennadius) (homoptera: aleyrodidae). both toxins showed ovicidal activity to eggs, with lc(50) values of 447 and 629 mg l(-1) respectively. nymphs of b. tabaci were the most susceptible stages (lc(50) values were cal ...200717315271
efficacy of the entomopathogenic nematode, steinernema feltiae, against sweetpotato whitefly bemisia tabaci (homoptera: aleyrodidae) under laboratory and glasshouse conditions.the potential of using the entomopathogenic nematode steinernema feltiae to control the sweetpotato whitefly bemisia tabaci (gennadius) has been established in previous laboratory studies. however, laboratory studies can overestimate the level of control achieved by biocontrol agents in the glasshouse. glasshouse trials are therefore required to confirm laboratory results before full-scale commercial development is considered. under both controlled laboratory and glasshouse conditions high morta ...200717298677
ecdysteroids and juvenile hormones of whiteflies, important insect vectors for plant viruses.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 hemime ...200717258230
tropical whitefly ipm project.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 age ...200717222696
field evaluation of resistance to pyriproxyfen in bemisia tabaci (b biotype).we determined effects of aerial sprays of the insect growth regulator pyriproxyfen on sweetpotato whitefly, bemisia tabaci (gennadius) (b biotype), in arizona cotton (gossypium spp.) fields. we measured survival for males and females from a susceptible strain and a laboratory-selected resistant strain, as well as for hybrid female progeny from crosses between the strains. insects were exposed directly to pyriproxyfen sprays in the field or indirectly in the laboratory by rearing them on sprayed ...200717972644
development of silverleaf assay, protein and nucleic acid-based diagnostic techniques for the quick and reliable detection and monitoring of biotype b of the whitefly, bemisia tabaci (gennadius).the aim of this study was to develop and optimize silverleaf bioassay, esterase analysis and pcr-based techniques to distinguish quickly and reliably biotype b of the whitefly, bemisia tabaci (gennadius), from indian indigenous biotypes. zucchini and squash readily develop silverleaf symptoms upon feeding by the b biotype, but they are not readily available in indian markets. a local pumpkin variety 'big' was, therefore, used in silverleaf assay, which developed symptoms similar to those on zucc ...200717916268
[insecticide resistance of bemisia tabaci field populations].resistance to 13 insecticides in field populations of bemisia tabaci from six regions (fuzhou, zhangzhou, longyan, sanming, nanping, ningde) of fujian province, china was monitored by adult leaf-dipping bioassay. compared with the susceptible sud-s strain, all the six field populations exhibited high levels of resistance to lambda-cyhalothrin (838.38-2460.52 fold), fenpropathrin (244.64-834.29 fold), cypermethrin (116.02-266.35 fold), deltamethrin (81.75-124.18 fold), acephate (425.18-875.56 fol ...200717886654
reversal of resistance to pyriproxyfen in the q biotype of bemisia tabaci (hemiptera: aleyrodidae).pyriproxyfen, a juvenile hormone (jh) mimic, is a biorational insecticide that disrupts insect development. it is one of the principal insecticides being used to control bemisia tabaci (gennadius) on cotton, and has many environmentally positive attributes that make it compatible with integrated pest management (ipm) programs. in israel, a high level of resistance to pyriproxyfen has been observed in several isolated regions. here, tests were conducted to establish whether temporal refuges from ...200717582630
gene expression in pyriproxyfen-resistant bemisia tabaci q biotype.pyriproxyfen is a biorational insecticide that acts as a juvenile hormone (jh) analogue and disrupts insect development with an unknown molecular mode of action. pyriproxyfen is one of the major insecticides used to control the whitefly bemisia tabaci (gennadius) and comply with integrated pest management (ipm) programmes, resulting in minimal effects on the environment, humans and beneficial organisms. during the last few years, resistance to pyriproxyfen has been observed in several locations ...200717569108
tissue-specific gene silencing by rna interference in the whitefly bemisia tabaci (gennadius).the hemipteran whitefly bemisia tabaci (gennadius) species complex and the plant viruses they transmit pose major constraints to vegetable and fiber production, worldwide. the whitefly tissue- and developmental-specific gene expression has not been exhaustively studied despite its economic importance. in 2002, a functional genomic project was initiated, which generated several thousands expressed sequence tags (ests) and their sequence. this project provides the basic information to design exper ...200717550829
toxicity of insecticides to the sweetpotato whitefly (hemiptera: aleyrodidae) and its natural enemies.efficient chemical control is achieved when insecticides are active against insect pests and safe to natural enemies. in this study, the toxicity of 17 insecticides to the sweetpotato whitefly, bemisia tabaci (gennadius), and the selectivity of seven insecticides to natural enemies of this insect pest were evaluated. to determine the insecticide toxicity, b. tabaci adults were exposed to abamectin, acephate, acetamiprid, cartap, imidacloprid, malathion, methamidophos, bifenthrin, cypermethrin, d ...200717523144
effects of azadirachtin, abamectin, and spinosad on sweetpotato whitefly (homoptera: aleyrodidae) on tomato plants under laboratory and greenhouse conditions in the humid tropics.direct and residual toxicity of neemazal-t/s (azadirachtin), success (spinosad), and abamectin was tested against different life stages of sweetpotato whitefly, bemisia tabaci (gennadius) (homoptera: aleyrodidae), under air-conditioned laboratory conditions and in a tropical net greenhouse. neemazal-t/s and abamectin deterred the settling of adults on tomato, lycopersicon esculentum mill (solanaceae), plants and consequently reduced egg deposition. no such effect was detected for success. all th ...200717461066
[flight behaviors of bemisia tabaci and corresponding ipm strategies].bemisia tabaci, a pest insect with stronger capabilities of flying and host plant-exploitation, is capable of flying 150 m high and over a distance as far as 7 km, but hardly flies higher than 0. 5 m and long distance in food-abundant areas. b. tabaci has the characteristics of both searching-and migrating flying, which enable it to exploit and locate on suitable hosts. up to now, no oogenesis-flight syndrome of b. tabaci has been detected. visual spectrum, air temperature and relative humidity, ...200717450755
mitochondrial dna variability and development of a pcr diagnostic test for populations of the whitefly bemisia afer (priesner and hosny).the whitefly, bemisia afer (hemiptera; aleyrodidae), is emerging as a major agricultural pest. the current identification methods based on adult and pupal morphology are laborious and unreliable. a diagnostic polymerase chain reaction (pcr) protocol was developed for the first time in this study to discriminate b. afer from other whitefly species. primers specific to mitochondrial cytochrome oxidase i gene (mtcoi) were designed to amplify a band of approx 650 bp. the pcr products were sequenced ...200717401147
some biological features of cotton whitefly, bemisia tabaci (homoptera: aleyrodidae) on various host plants.development and reproduction of the cotton whitefly, bemisia tabaci (gennadius) were studied on aubergine, tomato and potato under laboratory conditions (30 degrees c and 55% rh). total life cycle from egg to adult was 14.9, 20.0 and 14.2 days on aubergine, tomato and potato, respectively. immature mortality were 12.9, 18.1 and 12.3% at the same three host plants. females of b. tabaci oviposited means of 51.8, 60.1 and 67.5 eggs on aubergine, tomato and potato, respectively and had a mean longev ...200719090122
within-plant distribution of bemisia tabaci (homoptera: aleyrodidae) adults and immatures on greenhouse-grown winter cucumber plants.within-plant distribution of adults, pupae, nymphs, and eggs of bemisia tabaci (gennadius) (homoptera: aleyrodidae) on leaves of greenhouse-grown winter cucumber, cucumis sativum l., plants were studied in field plots for integrated pest management decision making. distribution of specific life stages depended on the leaf positions. the leaves with most abundance and low or lowest variation of whiteflies were leaves 8-12 for adults, 8-11 for pupae, 6-12 for nymphs, and 6-9 for eggs. in light of ...200717849865
evidence from molecular markers and population genetic analyses suggests recent invasions of the western north pacific region by biotypes b and q of bemisia tabaci (gennadius).invasive events by bemisia tabaci (gennadius) biotypes in various parts of the world are of continuing interest. the most famous is biotype b that has caused great economic losses globally. in addition, biotype q has also recently been reported to be a new invasive pest. these two biotypes have been monitored for some time in the western north pacific region, but the invasive events and population genetic structures of these two biotypes are still not clear in this region. in this study, the mit ...200717716487
assessment of herbivore performance on host plants.two models for assessing the performance of herbivores on a variety of host plants are developed by combining knowledge of population genetics and population ecology, especially that of the fixation probability of mutant genes. the absolute host performance model precisely assesses host performance for one herbivore population based on parameters of fecundity, larval survivorship, and selection pressure. the relative host performance model compares host performance for one population among diffe ...200717716460
[biology and non-preference for oviposition by bemisia tabaci (gennadius) biotype b (hemiptera: aleyrodidae) on cotton cultivars].the purposes of this work were to evaluate some biological aspects of bemisia tabaci (gennadius) biotype b at egg and nymphal stages and to evaluate the non-preference for oviposition and its correlation with the number and type of trichomes on the cotton cultivars brs ipê, brs 186-precoce 3, brs acala, brs verde, brs-200 marrom, brs cedro, brs ita 90-2 and brs aroeira. the experiments were conducted in climatic chambers at 28 +/- 2 degrees c, 70% rh and photophase of 14h, and in greenhouse. egg ...200717710328
introgression of resistance genes between populations: a model study of insecticide resistance in bemisia tabaci.introgression is a key process in conservation biology, genetic modification of (crop) species and in the evolutionary ecology of many species. here we consider the case of introgression of insecticide resistance in the whitefly, bemisia tabaci. b. tabaci is a species complex consisting of a range of biotypes, known to have a high degree of inter-biotype reproductive isolation. in areas where insecticide resistant and susceptible biotypes of b. tabaci coexist, introgression of the resistance gen ...200717658572
adult bemisia tabaci biotype b can induce silverleafing in squash.bemisia tabaci biotype b is one of three genetic groups able to induce silverleafing in squash. several earlier studies had observed that this physiological change was induced only through the feeding of juvenile whiteflies. this study uses adult males only to show that after 11 days the adult males were able to begin to induce silverleafing. further, the response was density-dependent with 120 adults inducing the first signs of silverleafing in 11 days, 90 adults in 13 days and 60 adults in 15 ...200717645825
global relationships of bemisia tabaci (hemiptera: aleyrodidae) revealed using bayesian analysis of mitochondrial coi dna sequences.bemisia tabaci (gennadius) (hemiptera: aleyrodidae) is a species complex that is one of the most devastating agricultural pests worldwide and affects a broad range of food, fiber and ornamental crops. unfortunately, using parsimony and neighbor joining methods, global phylogenetic relationships of the major races/biotypes of b. tabaci remain unresolved. aside from the limitations of these methods, phylogenetic analyses have been limited to only small subsets of the global collection of b. tabaci ...200717627853
potentiation/antagonism of pyrethroids with organophosphate insecticides in bemisia tabaci (homoptera: aleyrodidae).the binary mixtures of pyrethroids cypermethrin, alpha-cypermethrin, zeta-cypermethrin, bifenthrin, fenpropathrin, lambda-cyhalothrin, and deltamethrin plus organophosphates ethion, profenofos, chlorpyrifos, quinalphos, acephate, methamidophos, methyl parathion, and triazophos were evaluated on putatively resistant field populations of bemisia tabaci (gennadius) (homoptera: aleyrodidae) from pakistan using a leaf-dip bioassay. ethion exhibited good potentiation with all the pyrethroids. quinalph ...200717598552
plant-mediated interactions between whiteflies, herbivores, and natural enemies.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, ...200817877454
high-throughput allelic discrimination of b and q biotypes of the whitefly, bemisia tabaci, using taqman allele-selective pcr.b and q biotypes of the whitefly, bemisia tabaci (gennadius), are generally regarded as the most significant given their global distribution and strong resistance to insecticides. since these biotypes can coexist and differ markedly in their insecticide resistance profiles, a rapid but reliable means of discriminating between them would be a valuable complement to resistance monitoring and management programmes. recently, pcr-based methods have been developed to determine the biotype status of b ...200817972303
bioassay evaluation of the entomopathogenic fungi, beauveria bassaina vuellemin against eggs and nymphs of bemisia tabaci gennadius (homoptera: aleyrodidae).this study was carried out to determine the lethal effect of the entomopathogenic fungi, beauveria bassaina vuell. on eggs, young and old nymphs of the whitefly, bemisia tabaci genn. mortality percentage was significantly differed based on stage of b. tabaci and conidial concentrations of b. bassina. average of the infection level to insect was very low particularly in eggs with only 4.49%, even with higher conidial concentrations (6 x 10(6) conidia ml(-1)). whereas, it was higher with 1st and 2 ...200818819641
functional and numerical responses of eretmocerus mundus mercet (hymenoptera: aphelinidae) parasitizing cotton whitefly, bemisia tabaci gennadius (homoptera: aleyrodidae).laboratory experiments were conducted to measure the functional and numerical responses of eretmocerus mundus mercet parasitizing cotton whitefly, bemisia tabaci gennadius. parasitoids were isolated singly for 24 h in 5 cm petri dishes with either 5, 10, 20, 40, 60 or 100 second nymphal stages of b. tabaci. results showed a typical type ii functional response, with up to 43.2 hosts attacked when 100 hosts were provided. the rate of attack and handling time were 0.0465 and 0.3341 days, respective ...200818810971
twelve new polymorphic microsatellite loci and pcr multiplexing in the whitefly, bemisia tabaci.twelve new dinucleotide microsatellite loci of the whitefly, bemisia tabaci, were obtained from enriched genomic libraries. three polymerase chain reaction multiplex sets comprising three, five and four loci were optimized and characterized across 133 b. tabaci females from israeli rearings and natural populations collected in four mediterranean countries (tunisia, france, spain and morocco). there were three to 24 alleles per locus and the observed heterozygosity was from 0.084 to 0.420. deviat ...200821585955
organophosphates' resistance in the b-biotype of bemisia tabaci (hemiptera: aleyrodidae) is associated with a point mutation in an ace1-type acetylcholinesterase and overexpression of carboxylesterase.organophosphate (op) insecticides are inhibitors of the enzyme acetylcholinesterase (ache), which terminates nerve impulses by catalyzing the hydrolysis of the neurotransmitter acetylcholine. previous biochemical studies in bemisia tabaci (hemiptera: aleyrodidae) proposed the existence of two molecular mechanisms for ops' resistance: carboxylesterase- (coe) mediated hydrolysis or sequestration and decreased sensitivity of ache. here, two acetylcholinesterase genes, ace1 and ace2, have been fully ...200818721883
inheritance of resistance to pyriproxyfen in bemisia tabaci (hemiptera: aleyrodidae) males and females (b biotype).we evaluated effects of the insect growth regulator pyriproxyfen on bemisia tabaci (gennadius) (b biotype) (hemiptera: aleyrodidae) males and females in laboratory bioassays. insects were treated with pyriproxyfen as either eggs or nymphs. in all tests, the lc50 for a laboratory-selected resistant strain was at least 620 times greater than for an unselected susceptible strain. when insects were treated as eggs, survival did not differ between males and females of either strain. when insects were ...200818613596
over-expression of cytochrome p450 cyp6cm1 is associated with high resistance to imidacloprid in the b and q biotypes of bemisia tabaci (hemiptera: aleyrodidae).the two most damaging biotypes of bemisia tabaci, b and q, have both evolved strong resistance to the neonicotinoid insecticide imidacloprid. the major mechanism in all samples investigated so far appeared to be enhanced detoxification by cytochrome p450s monooxygenases (p450s). in this study, a polymerase chain reaction (pcr) technology using degenerate primers based on conserved p450 helix i and heme-binding regions was employed to identify p450 cdna sequences in b. tabaci that might be involv ...200818510975
[factors affecting oviposition of bemisia tabaci (genn.) biotype b in sweet pepper].bemisia tabaci (gen.) biotype b is considered a pest of economical importance for several vegetables. the oviposition behaviour of the whilefly 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 dist ...200818506298
yellow sticky trap catches of parasitoids of bemisia tabaci (hemiptera: aleyrodidae) in vegetable crops and their relationship to in-field populations.we examined the relationship of yellow sticky trap captures of bemisia tabaci (gennadius) biotype b parasitoids to the local population of parasitoids as measured by leaf samples of parasitized whiteflies and mass release of parasitoids. traps were placed in experimental collard and cowpea field plots in charleston, sc, and in commercial organic fields of spring cantaloupe and watermelon in the imperial valley, ca. the exotic parasitoid eretmocerus emiratus zolnerowich and rose was released in i ...200818419911
baseline susceptibility of bemisia tabaci b biotype (hemiptera: aleyrodidae) populations from california and arizona to spiromesifen.susceptibility to spiromesifen, a tetronic acid derivative, was determined for three imidacloprid-resistant strains and 12 geographically discrete natural populations of bemisia tabaci (gennadius) (=bemisia argentifolii bellows & perring) (hemiptera: aleyrodidae) from california and arizona by laboratory bioassays. newly emerged first instars were sprayed with aqueous serial dilutions of spiromesifen and evaluated for toxicity to establish baseline susceptibility data. interpopulation variabilit ...200818330133
life table analysis for immatures and female adults of the predatory beetle, delphastus catalinae, feeding on whiteflies under three constant temperatures.immature development and reproductive life history of delphastus catalinae (horn) (coleoptera: coccinellidae) feeding on bemisia tabaci biotype b (gennadius) (homoptera: aleyrodidae) (= b. argentifolii bellows and perring) immatures was studied at three constant temperatures: 22, 26 and 30 degrees c. lower developmental threshold temperatures (t0) were estimated at 9 and 9.9 degrees c, for males and females, respectively. female adults weighed slightly more than males (0.587 and 0.505 mg, respec ...200820345295
antifeedant activity of botanical crude extracts and their fractions on bemisia tabaci (homoptera: aleyrodidae) adults: iii. quassia amara (simaroubaceae).bemisia tabaci is a key virus vector on several crops worldwide. then, a preventive approach to deal with viral epidemics may be the deployment of repellents or phagodeterrents at earlier stages of plant development (critical period). thus, the crude extract and four fractions thereof (water, water: methanol, methanol, and diethyl ether) of bitterwood (quassia amara, simaroubaceae) were tested for phagodeterrence to b. tabaci adults under greenhouse conditions, on tomato plants, in costa rica. b ...200819419106
antifeedant activity of botanical crude extracts and their fractions on bemisia tabaci (homoptera: aleyrodidae) adults: ii. sechium pittieri (cucurbitaceae).bemisia tabaci is a key pest of vegetables and other crops worldwide, but it is a particularly serious problem in the tropics, due to its ability to transmit several types of viruses, especially begomoviruses (geminiviridae). therefore, a preventive approach to deal with viral epidemics may be the deployment of repellents or phagodeterrents at earlier stages of plant development (critical period). thus, the crude extract and four fractions thereof (water, water: methanol, methanol, and diethyl e ...200819419105
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