| 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 ... | 2007 | 17582630 |
| 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 ... | 2007 | 17569108 |
| 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 ... | 2007 | 17550829 |
| 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 ... | 2007 | 17523144 |
| 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 ... | 2007 | 17461066 |
| [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, ... | 2007 | 17450755 |
| 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 ... | 2007 | 17401147 |
| 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 ... | 2006 | 17385531 |
| 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 ... | 2006 | 17385496 |
| 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 ... | 2007 | 17323411 |
| 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 ... | 2007 | 17315271 |
| 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 ... | 2007 | 17298677 |
| 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 ... | 2007 | 17258230 |
| 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 ... | 2007 | 17222696 |
| [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 ... | 2006 | 17209395 |
| 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 ... | 2007 | 20302459 |
| 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. ... | 2006 | 17192620 |
| 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 ... | 2005 | 17119628 |
| 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 ... | 2006 | 16967908 |
| 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 ... | 2006 | 16937698 |
| 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 ... | 2006 | 16937666 |
| 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 ... | 2006 | 16686130 |
| insect resistance in tomato accessions and their hybrid derivatives in tamil nadu, india. | host plant resistance offers a viable alternative to the use of chemical insecticides for managing insects infesting tomato. hence, a study was carried out in tamil nadu, india during 1996 to 2004. an exhaustive germplasm comprising 321 tomato accessions including cultivars, wild lines, land races, tribal/native tomatoes was gathered from various sources and screened for resistance against the major pest namely fruit worm, helicoverpa armigera hubner (noctuidae: lepidoptera). in the field screen ... | 2005 | 16628895 |
| 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 ... | 2006 | 16596346 |
| 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 ... | 2005 | 16539159 |
| [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 ... | 2005 | 16515210 |
| 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 ... | 2006 | 16441901 |
| 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 ... | 2006 | 16360952 |
| pathogenicity of the entomopathogenic fungus, lecanicillium muscarium, against the sweetpotato whitefly bemisia tabaci under laboratory and glasshouse conditions. | the potential for using the entomopathogenic fungus lecanicillium muscarium to control the sweetpotato whitefly, bemisia tabaci has been established in the laboratory by other studies. laboratory studies however frequently overestimate the level of control achieved by biological control agents in the glasshouse. before full-scale commercial or field development is considered, glasshouse trials are required to confirm laboratory results. under both controlled laboratory and glasshouse conditions ... | 2005 | 16244900 |
| 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 ... | 2006 | 16235269 |
| compatibility of the entomopathogenic fungus lecanicillium muscarium and insecticides for eradication of sweetpotato whitefly, bemisia tabaci. | the compatibility of the entomopathogenic fungus lecanicillium muscarium and chemical insecticides used to control the second instar stages of the sweetpotato whitefly, bemisia tabaci, was investigated. the effect on spore germination of direct exposure for 24 h to the insecticides imidacloprid, buprofezin, teflubenzuron and nicotine was determined. only exposure to buprofezin was followed by acceptable spore germination. however, all chemicals significantly reduced spore germination when compar ... | 2005 | 16160767 |
| how predatory mites find plants with whitefly prey. | we investigated the searching behaviour of two species of predatory mites, typhlodromips swirskii (athias-henriot) and euseius scutalis (athias-henriot), both known to feed on immature stages of the whitefly bemisia tabaci gennadius. when released in a greenhouse inside a circle of cucumber plants that were alternatingly clean or infested with immature whiteflies, the mites took several days to find plants. both species were recaptured significantly more on plants with whiteflies. this suggests ... | 2005 | 16132740 |
| development, survivorship and reproduction of eretmocerus sp. nr furuhashii (hymenoptera: aphelinidae) parasitizing bemisia tabaci (hemiptera: aleyrodidae) on glabrous and non-glabrous host plants. | the developmental, survivorship and reproductive biology of eretmocerus sp. nr furuhashii rose & zolnerowich parasitizing bemisia tabaci (gennadius) biotype b on tomato, cucumber, eggplant and collard at 26+/-0.5 degrees c was studied. the mean longevity ranged from 6.5 days on tomato to 8.1 days on collard. the mean lifetime fecundities on tomato, cucumber, eggplant and collard were 35.4, 37.3, 41.4 and 46.4 eggs, whereas the mean lifetime fertility was 20.2, 22.7, 28.3 and 33.6 offspring, resp ... | 2005 | 16048679 |
| natural products: seasonal variation in trichome counts and contents in lycopersicum hirsutum f. glabratum. | wild tomato leaves possess a pest-resistance mechanism in their glandular trichomes and the exudates they produce. type iv and vi glandular trichomes on the leaves of five wild tomato accessions of lycopersicum hirsutum f. glabratum (pi 126449, pi 134417, pi 134418, pi 251304, and la 407) grown under greenhouse conditions were counted. major chemical compounds from glandular leaf trichomes of the accessions tested were extracted, purified, and quantified at different periods during the growing s ... | 2005 | 16047884 |
| 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 ... | 2005 | 15960874 |
| [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 ... | 2005 | 15943367 |
| foraging behavior and prey interactions by a guild of predators on various lifestages of bemisia tabaci. | the sweetpotato whitefly, bemisia tabaci (gennadius) is fed on by a wide variety of generalist predators, but there is little information on these predator-prey interactions. a laboratory investigation was conducted to quantify the foraging behavior of the adults of five common whitefly predators presented with a surfeit of whitefly eggs, nymphs, and adults. the beetles, hippodamia convergens guerin-meneville and collops vittatus (say) fed mostly on whitefly eggs, but readily and rapidly preyed ... | 2004 | 15861217 |
| biorational insecticides: mechanism and cross-resistance. | potency and cross-resistance of various biorational insecticides, exemplified by the whitefly bemisia tabaci, have been studied. bemisia tabaci were exposed to the juvenile hormone mimic pyriproxyfen for the past 12 years resulting in an over 2,000-fold resistance, but there was no appreciable cross-resistance with the benzoylphenyl urea novaluron. similarly, no cross-resistance was found between pyriproxyfen and the two neonicotinoids, acetamiprid and imidacloprid. on the other hand, a slight c ... | 2005 | 15756702 |
| resistance of insect pests to neonicotinoid insecticides: current status and future prospects. | the first neonicotinoid insecticide introduced to the market was imidacloprid in 1991 followed by several others belonging to the same chemical class and with the same mode of action. the development of neonicotinoid insecticides has provided growers with invaluable new tools for managing some of the world's most destructive crop pests, primarily those of the order hemiptera (aphids, whiteflies, and planthoppers) and coleoptera (beetles), including species with a long history of resistance to ea ... | 2005 | 15756698 |
| the susceptibility of immature stages of bemisia tabaci to the entomopathogenic fungus lecanicillium muscarium on tomato and verbena foliage. | lecanicillium muscarium is a widely occurring entomopathogenic fungus. laboratory studies were conducted to determine the efficacy of l. muscarium against different instars of bemisia tabaci on tomato and verbena foliage after two incubation times (3 and 7 days). significant reduction in b. tabaci numbers were recorded on fungus treated plants (p < 0.001). second instar b. tabaci proved most susceptible to l. muscarium infection. there was no significant difference in mortality of b. tabaci seco ... | 2005 | 15750729 |
| conservation of natural enemies in cotton: comparative selectivity of acetamiprid in the management of bemisia tabaci. | the integrated control concept emphasizes the importance of both chemical and biological control for pest suppression in agricultural systems. a two-year field study was conducted to evaluate the selectivity of acetamiprid for the control of bemisia tabaci (gennadius) in cotton compared with a proven selective regime based on the insect growth regulators (igrs) pyriproxyfen and buprofezin. acetamiprid was highly effective in controlling all stages of b tabaci compared with an untreated control, ... | 2005 | 15712368 |
| identification of the molting hormone of the sweet potato (bemisia tabaci) and greenhouse (trialeurodes vaporariorum) whitefly. | in order to identify the whitefly molting hormone, whole body extracts of mature 4th instar and newly formed pharate adult bemisia tabaci (biotype b) and trialeurodes vaporariorum were prepared and subjected to reverse phase high performance liquid chromatography (rphplc). ecdysteroid content of fractions was determined by enzymeimmunoassay (eia). the only detectable ecdysteroids that were present in significant amounts in whitefly extracts were ecdysone and 20-hydroxyecdysone. the concentration ... | 2005 | 15686645 |
| [interactive system of delphastus catalinae and its competitor: interspecies competition]. | delphastus catalinae and serangium japonicum are the important natural enemies of bemisia tabaci, of which, the former is exotic, and the latter is indigenous. in this paper, the influence of interspecies competition on the population growth of d. catalinae and s. japonicum was studied under conditions of single and mixed rearing, and lotka-volterra equation was used to simulate the competition when more and less preys provided for the two ladybirds. the results showed that the population growth ... | 2004 | 15334980 |
| characterization and molecular cloning of a glutathione s-transferase from the whitefly bemisia tabaci (hemiptera: aleyrodidae). | glutathione s-transferases (gst) catalyzing the conjugation of reduced glutathione to a vast range of xenobiotics including insecticides were characterized in the whitefly bemisia tabaci. gst activities were determined in susceptible and resistant strains of b. tabaci towards artificial substrates, i.e. 1-chloro-2,4-dinitrobenzene (cdnb) in a photometric microplate assay and monochlorobimane (mcb) in a fluoroemtric microplate assay and characterized by their michaelis-menten kinetics. the inhibi ... | 2004 | 15041016 |
| methods of surveying the incidence and severity of cassava mosaic disease and whitefly vector populations on cassava in africa: a review. | field surveys in many cassava growing areas of africa have assessed the incidence and severity of cassava mosaic disease (cmd), populations of the whitefly vector (bemisia tabaci), and the distribution of cassava mosaic begomoviruses (cmbs). the methods employed differ greatly between countries and attempts at standardization were made in recent cmd surveys in east and central africa, notably in the systemwide whitefly ipm project, which provides a paradigm for future work on cmbs and whiteflies ... | 2004 | 15036844 |
| the ecology and epidemiology of whitefly-transmitted viruses in latin america. | whitefly-transmitted geminiviruses are the most important constraint to the production of common bean and vegetable crops in the tropical lowlands and mid-altitude valleys of latin america. currently, over 30 distinct species of geminiviruses that are transmitted by the whitefly bemisia tabaci infect common bean, tomato, pepper, cucurbits and other horticultural crops. a climate probability model (using floramap) was obtained using data from 304 geo-referenced locations where b. tabaci and gemin ... | 2004 | 15036836 |
| [effectiveness of eretmocerus sp. and aschersonia aleyrodis in controlling bemsia tabaci populations]. | the effectiveness of eretmocerus sp. and aschersonia aleyrodis in controlling bemisia tabaci populations on cucumber were determined in separated and combined greenhouse experiments. the results showed that after spraying a. aleyrodis (5 x 10(6) spores per ml, twice per generation) and releasing eretmocerus sp. (3 female per plant, twice per generation), 95.74% and 57.58% of whitefly populations were controlled, respectively. however, when the two natural enemies were used together with the same ... | 2003 | 15031927 |
| sequence analysis of dna fragments from the genome of the primary endosymbiont of the whitefly bemisia tabaci. | the whitefly bemisia tabaci contains a primary prokaryotic endosymbiont housed within specialized cells in the body cavity. two dna fragments from the endosymbiont, totaling 33.3 kilobases, were cloned and sequenced. in total, 37 genes were detected and included the ribosomal rna operon and genes for ribosomal rna proteins. the guanine plus cytosine of the dna was 30.2 mol%, different from that of endosymbionts of other plant sap-sucking insects. | 2004 | 15018108 |
| phytoseiid predator of whitefly feeds on plant tissue. | predatory mites of the family phytoseiidae feed on herbivorous mites and insects but they also use a variety of non-prey food items, such as pollen and nectar. plant tissue is another potential food source. we investigated whether plant feeding occurs in the two phytoseiids euseius scutalis (athias-henriot) and typhlodromips swirskii (athias-henriot), which are natural enemies of whiteflies. these predatory mites can suppress populations of bemisia tabaci (gennadius) on isolated plants and are c ... | 2003 | 14756398 |
| phytoseiid predators of whiteflies feed and reproduce on non-prey food sources. | two phytoseiid species, euseius scutalis (athias-henriot) and typhlodromips swirskii (athias-henriot), are able to suppress whitefly populations on single plants and are candidate biological control agents for whiteflies such as bemisia tabaci (gennadius). these species can feed on pollen and insect-produced honeydew and these food sources are likely to be available in crops. if the utilization of these food types results in increased reproduction or survival, populations of predators can persis ... | 2003 | 14756397 |
| volatile emissions triggered by multiple herbivore damage: beet armyworm and whitefly feeding on cotton plants. | plants are commonly attacked by more than one species of herbivore, potentially causing the induction of multiple, and possibly competing, plant defense systems. in the present paper, we determined the interaction between feeding by the phloem feeder silverleaf whitefly (swf), bemisia tabaci gennadius (b-biotype = b. argentifolii bellows and perring), and the leaf-chewing beet armyworm (baw), spodoptera exigua hübner, with regard to the induction of volatile compounds from cotton plants. compare ... | 2003 | 14682532 |
| inheritance of pyriproxyfen resistance in the whitefly, bemisia tabaci (q biotype). | the inheritance of resistance to pyriproxyfen, an insect growth regulator (a juvenoid, with ovicidal and larvicidal activities), was studied in the whitefly bemisia tabaci (gennadius). two parental strains, both belonging to q biotype, were assayed with pyriproxyfen; a susceptible strain (alm-1) originating from spain and a pyriproxyfen-resistant one (pyri-r) from israel. the resistance ratio between the two parental strains was approximately 7,000-fold. concentration-mortality lines for f(1) he ... | 2003 | 14635179 |
| identification of biochemical markers linked to neonicotinoid cross resistance in bemisia tabaci (hemiptera: aleyrodidae). | the whitefly, bemisia tabaci (hemiptera: aleyrodidae), is a serious pest in many cropping systems world-wide and occurs in different biotypes. the most widespread one is the b-type, whereas the q-biotype is nowadays still mostly restricted to southern spain. neonicotinoid cross-resistance is known at a high level in q-types from spain and individual samples collected in italy and germany. now we detected for the first time high neonicotinoid cross-resistance in a b-type from israel. target site ... | 2003 | 14635178 |
| novaluron (rimon), a novel igr: potency and cross-resistance. | the potency of novaluron on laboratory susceptible and field strains of s. littoralis resembles that of chlorfluazuron and both compounds are about 20-fold more potent than teflubenzuron. no appreciable resistance to novaluron or chlorfluazuron was observed in a field strain of spodoptera littoralis collected from cucumber field in the central part of israel. on the other hand, the field strain showed a mild resistance of about 4-fold to teflubenzuron as compared to the laboratory susceptible st ... | 2003 | 14635177 |
| cotton leaf curl disease, a multicomponent begomovirus complex. | summary cotton leaf curl is a serious disease of cotton and several other malvaceous plant species that is transmitted by the whitefly bemisia tabaci. the disease is, at this time, endemic throughout pakistan and epidemic in western india. affected cotton plants exhibit a range of symptoms such as leaf curling, stunted growth and a poor yield of cotton fibre. in addition, affected plants may develop leaf-like outgrowths from the veins on the undersides of leaves. a number of distinct begomovirus ... | 2003 | 20569402 |
| the efficacy of the entomopathogenic nematode, steinernema feltiae, against the immature stages of bemisia tabaci. | | 2003 | 12877837 |
| herbivore host plant selection: whitefly learns to avoid host plants that harbour predators of her offspring. | evidence is accumulating that herbivorous arthropods do not simply select host plants based on their quality, but also on the predation risk associated with different host plants. it has been suggested that herbivores exclude plant species with high predation risk from their host range. this assumes a constant, predictable predation risk as well as a rather static behaviour on the part of the herbivore; plants are ignored irrespective of the actual predation risk. we show that adult females of a ... | 2003 | 12802671 |
| plant nitrogen status rapidly alters amino acid metabolism and excretion in bemisia tabaci. | the effect of plant nitrogen (n) status on the content and distribution of free amino acids in the bodies and honeydew of silverleaf whiteflies bemisia tabaci (gennadius) biotype b (= b. argentifolii bellows and perring) was determined. whiteflies fed for 4 days on cotton leaves that received high or low n fertility. for low-n plants, photosynthesis and leaf total n levels were decreased, and a much-reduced amount of free amino acids was recovered in phloem sap. low n fertility did not affect wh ... | 2002 | 12770130 |
| molecular characterization of whitefly, bemisia tabaci (hemiptera: aleyrodidae) populations infesting cassava. | bemisia tabaci (gennadius) populations, collected from cassava and other plants in major cassava-cultivation areas of sub-saharan africa and from elsewhere around the world, were studied to determine their biotype status and genetic variation. random amplified polymorphic dna-polymerase chain reaction (rapd-pcr) markers were used to examine the genetic structure of the populations. the dendogram obtained using the neighbour joining method (nj) split the cassava-associated populations from the no ... | 2003 | 12699530 |
| novaluron (rimon), a novel igr--mechanism, selectivity and importance in ipm programs. | novaluron (rimon), a new igr, acts by both ingestion and contact. it is a powerful toxicant for controlling lepidopteran larvae resulting in lc-90 values of 0.42 and 0.30 mg a.i./liter for spodoptera littoralis and s. exigua, respectively. its residual activity under field conditions ranges between 10 and 30 days depending on environmental conditions. the compound is a powerful toxicant against developing stages of whiteflies, resulting in lc-90 values of 0.68 and 8.56 mg a.i./liter for bemisia ... | 2002 | 12696429 |
| phytoseiid predators suppress populations of bemisia tabaci on cucumber plants with alternative food. | phytoseiids are known to attack whiteflies, but it is an open question whether they can be used for biological control of these pest insects. preselection experiments in the laboratory showed that two out of five phytoseiid species tested, euseius scutalis and typhlodromips swirskii, stood out in terms of their ability to develop and reproduce on a diet of bemisia tabaci immatures. in this paper, we show that both predators are able to suppress whitefly populations on isolated cucumber plants in ... | 2002 | 12593512 |
| dynamics of insecticide resistance in bemisia tabaci: a case study with the insect growth regulator pyriproxyfen. | the dynamics of pyriproxyfen resistance in bemisia tabaci (gennadius) have been studied intensively in cotton fields and greenhouses in israel. high resistance to pyriproxyfen evolved one year after its introduction for use on flowers in greenhouses, after three successive applications. after ten years of pyriproxyfen use in cotton fields, with only one application per season, a high level of resistance was observed, but its rate of development differed among localities. it is hypothesized that ... | 2002 | 12449527 |
| mutations in the bemisia tabaci para sodium channel gene associated with resistance to a pyrethroid plus organophosphate mixture. | the voltage-gated sodium channel is the primary target site of pyrethroid insecticides. in some insects, super knockdown resistance (super-kdr) to pyrethroids is caused by point mutations in the linker fragment between transmembrane segments 4 and 5 of the para-type sodium channel protein domain ii (iis4-5). here, we identify two mutations in the iis4-5 linker of the para-type sodium channel of the whitefly, bemisia tabaci: methionine to valine at position 918 (m918v) and leucine to isoleucine a ... | 2002 | 12429130 |
| biorational agents--mechanism and importance in ipm and irm programs for controlling agricultural pests. | among the new approaches for controlling agricultural pests is the development of novel compounds affecting specific processes in insects such as chitin synthesis inhibitors, juvenile hormone mimics and ecdysone agonists. in addition, efforts have been made to develop compounds acting selectively on groups of insects by inhibiting or enhancing biochemical sites such as respiration (diafenthiuron), the nicotinyl acetylcholine receptors (imidacloprid and acetamiprid), the gaba receptors (avermecti ... | 2001 | 12425057 |
| bemisia tabaci (homoptera: aleyrodidae) biotype b colonization on okra- and normal-leaf upland cotton strains and cultivars. | we compared smooth-leaf okra- and normal-leaf upland cotton (gossypium hirsutum l.) strains and cultivars for susceptibility to colonization by bemisia tabaci (gennadius) biotype b. experiments were conducted at seven field sites, five at holtville, ca, and two at maricopa, az, during 1996-2000. okra-leaf strains and cultivars, as a group, had lower numbers of adults, eggs, and nymphs compared with normal-leaf strains and cultivars indicating the potential of okra-leaf genetic traits for reducin ... | 2002 | 12216814 |
| conservation of predatory arthropods in cotton: role of action thresholds for bemisia tabaci (homoptera: aleyrodidae). | studies were conducted in 1994 and 1995 to examine the effects of a range of action thresholds for managing bemisia tabaci (gennadius) biotype b (= b. argentifolii bellows & perring) with insecticides in cotton on populations of arthropod predators in imperial valley, ca, and maricopa, az. application of insecticides significantly reduced population densities of spiders, geocoris punctipes (say), g. pallens (stål), orius tristicolor (white), nabis alternatus parshley, zelus renardii kolenati, hi ... | 2002 | 12216807 |
| new developments in insecticide resistance in the glasshouse whitefly (trialeurodes vaporariorum) and the two-spotted spider mite (tetranychus urticae) in the uk. | a recent survey of insecticide resistance in two of the most problematic pests in uk glasshouses revealed some new developments. at least some individuals in all uk samples of trialeurodes vaporariorum that were tested resisted the insect growth regulator (igr) buprofezin. the most strongly resistant strains were unaffected by the field application rate of this compound, and even samples from populations that had never been exposed to buprofezin contained individuals that survived the highest co ... | 2002 | 11852636 |
| natural genomic and antigenic variation in whitefly-transmitted geminiviruses (begomoviruses). | begomoviruses have circular single-stranded dna genomes, cause many diseases of dicotyledons in areas with warm climates and are transmitted by whiteflies of the bemisia tabaci complex. their genomic and antigenic variation represents geography-related lineages that have little relation to host range. genomic variation resulting from mutation is amplified by acquisition of extra dna components, pseudo-recombination and recombination, both intraspecific and interspecific. recombination, especiall ... | 1999 | 11701828 |
| the emergence and dissemination of whitefly-transmitted geminiviruses in latin america. | the proliferation and rapid dissemination of whitefly-transmitted viruses of important food and industrial crops in latin america, have been the consequence of drastic changes in traditional cropping systems. some of the expanding non-traditional cash and export crops, such as soybean and several vegetables, have served as suitable reproductive hosts for the whitefly bemisia tabaci. this insect pest has been shown to transmit at least 20 different geminiviruses that affect different commercial a ... | 2001 | 11338381 |
| digestive, salivary, and reproductive organs of bemisia tabaci (gennadius) (hemiptera: aleyrodidae) b type. | a microscopic analysis of the morphology and ultrastructure of the digestive, salivary, and reproductive systems of adult bemisia tabaci (gennadius) (hemiptera: aleyrodidae) b type was conducted using light, scanning, and transmission electron microscopy. the internal anatomy of b. tabaci was found to be similar to that reported for trialeurodes vaporariorum. in a microscopic analysis of the salivary glands, we have shown that each primary salivary gland is composed of at least 13 cells varying ... | 2001 | 11268056 |
| development of a continuous whitefly cell line [homoptera: aleryrodidae: bemisia tabaci (gennadius)] for the study of begomovirus. | the whitefly bemisia tabaci (gennadius) is a widely distributed pest of many important food and fiber crops. this whitefly is also a vector of more than 70 plant-infecting viruses. a cell line was established in vitro using embryonic tissues from the eggs of bemisia tabaci (gennadius), b biotype (pseudonym b. argentifolii bellows & perring), and referred to as 'btb(ba)97, hunter-polston'. cell cultures were successfully inoculated with begomovirus (bgmv and tomov)-infected tomato plant sap. embr ... | 2001 | 11161991 |
| molecular markers for the identification and global tracking of whitefly vector-begomovirus complexes. | recent unprecedented upsurges in populations of the whitefly bemisia tabaci (genn.) have drawn much attention to its worldwide importance as an insect pest and as the vector of emergent begomoviruses (family: geminiviridae; genus: begomovirus). several begomoviruses that are considered 'new' and others previously regarded as minor pathogens have been linked to recent epidemics. recent studies have revealed much variation in begomoviruses, despite the view that dna-containing viruses do not rapid ... | 2000 | 11137175 |
| genetic relationships among biotypes of bemisia tabaci (hemiptera: aleyrodidae) based on aflp analysis. | genetic similarities between 13 samples belonging to nine reference biotypes and two field populations of bemisia tabaci (gennadius), one field population of b. medinae gómez-menor and another of b. afer priesner & hosny, were evaluated using amplified fragment length polymorphism (aflp) markers. the results indicate that b. tabaci biotypes can be grouped together with a minimum similarity coefficient of 0.32 and separated from the two other species with a similarity coefficient of 0.07. bemisia ... | 2000 | 11082556 |
| phylogenetic relationships of world populations of bemisia tabaci (gennadius) using ribosomal its1. | a phylogeny of bemisia tabaci is presented based on the its1 region of ribosomal dna. the monophyly of each biotype of bemisia is supported, and a strong biogeographic pattern is evident in the data. populations from the americas (including the a biotype) form a clade sister to a clade comprising the silverleafing or b biotype and a nonsilverleafing biotype from the north africa/mediterranean region. polymorphisms in rdna suggest that silverleafing is a recent phenomenon, while the nonsilverleaf ... | 2000 | 10877937 |
| effect of whitefly parasitoids on the cuticular lipid composition of bemisia argentifolii (homoptera: aleyrodidae) nymphs. | experiments were conducted to determine the effects of whitefly parasitoids on the cuticular lipid composition of the silverleaf whitefly, bemisia argentifolii bellows and perring [=sweetpotato whitefly, bemisia tabaci (gennadius), biotype b] nymphs. the cuticular lipids of b. argentifolii nymphs that had been attacked by parasitic wasps, either eretmocerus mundus mercet or encarsia pergandiella howard, were characterized by capillary gas chromatography and cgc-mass spectrometry and the results ... | 2000 | 10861868 |
| a phylogeographical analysis of the bemisia tabaci species complex based on mitochondrial dna markers | mitochondrial 16s ( approximately 550 bp) and cytochrome oxidase i (coi) ( approximately 700 bp) sequences were utilized as markers to reconstruct a phylogeography for representative populations or biotypes of bemisia tabaci. 16s sequences exhibited less divergence than coi sequences. of the 429 characters examined for coi sequences, 185 sites were invariant, 244 were variable and 108 were informative. coi sequence identities yielded distances ranging from less than 1% to greater than 17%. white ... | 1999 | 10583831 |
| lettuce infectious yellows virus: in vitro acquisition analysis using partially purified virions and the whitefly bemisia tabaci. | virions of lettuce infectious yellows virus (liyv; genus crinivirus) were purified from liyv-infected plants and their protein composition was analysed by sds-page and immunoblotting. virion preparations contained the major capsid protein (cp), but the minor capsid protein (cpm), p59 and the hsp70 homologue were also identified by immunoblot analysis. immunogold labelling analysis showed that cp constituted the majority of the liyv virion capsid, but cpm was also part of the capsid and localized ... | 1999 | 10355756 |
| vitellin of the sweet potato whitefly, bemisia tabaci: biochemical characterization and titer changes in the adult. | sds-page of the sweet potato whitefly (bemisia tabaci) egg extract showed one major band (approximately 190 kda) and two minor bands (approximately 75 kda and 67 kda). a distinct 190 kda band was also present in male extract. on sds gels the vitellin band of the greenhouse whitefly (trialeurodes vaporarium) was larger, about 220 kda. the native molecular mass of sweet potato whitefly vitellin was estimated to be 375 kda using 4-20% native porelimiting gel electrophoresis. its isoelectric point w ... | 1997 | 9041698 |
| biochemical evidence of haplodiploidy in the whitefly bemisia tabaci. | polymorphic esterase and acetylcholinesterase alleles in the whitefly bemisia tabaci were studied using electrophoretic and colorimetric assays. the segregation of these alleles between parental and f1 generations provided unequivocal evidence of haplodiploidy in this pest species. unmated females, heterozygous at a polymorphic locus, produced a 1:1 ratio of haploid males expressing either of the maternal alleles. although male offspring were produced by both virgin and mated females, the segreg ... | 1996 | 8734410 |
| virus-like particles in the mycetocytes of the sweetpotato whitefly, bemisia tabaci (homoptera, aleyrodidae). | | 1996 | 8812594 |
| localized migration and dispersal by the sweet potato whitefly, bemisia tabaci. | laboratory populations of the sweet potato whitefly, bemisia tabaci, have been shown to consist of both migratory and trivial flying morphs. the behavior of these forms as part of the process of short-range migration was examined under field conditions. insects were marked in a field of melons using fluorescent dust during two consecutive growing seasons. during the first growing season, passive traps used to collect living whiteflies, were placed along 16 equally spaced transects radiating from ... | 1996 | 28307104 |
| projuvenoids: synthesis and biological evaluation of sulfenylated, sulfinylated, and sulfonylated carbamates. | applying the proinsecticide principle developed earlier for neurotoxic carbamate insecticides, a series of new n-sulfenylated, n-sulfinylated, and n-sulfonylated derivatives of fenoxycarb were synthesized and evaluated for juvenile hormone mimicking activity. laboratory evaluations of the compounds using pieris brassicae and sitophilus oryzae, as well as field experiments using bemisia tabaci, showed that several symmetrical biscarbamates with either a sulfenyl or sulfinyl bridge possessed highe ... | 1996 | 8756313 |
| protease inhibitors of manduca sexta expressed in transgenic cotton. | to explore the effectiveness of insect derived protease inhibitors in protecting plants against insect feeding, anti-trypsin, anti-chymotrypsin and anti-elastase protease inhibitor (pi) genes from manduca sexta l. were expressed in transgenic cotton (gossypium hirsutum l.). from 198 independent transformants, 35 elite lines were further analyzed. under the control of the 35s promoter of camv, pi accumulated to approximately 0.1% of total protein, depending on the tissue analyzed. using cell-flow ... | 1995 | 24186707 |
| characterization and distribution of esterase electromorphs in the whitefly, bemisia tabaci (genn.) (homoptera: aleyrodidae). | esterase profiles were examined for over 40 populations of the whitefly, bemisia tabaci, obtained from native and cultivated plant hosts worldwide. twelve unique electromorphs were identified from distinct populations concentrated largely in central america, africa, and india. one electromorph, type b, has recently been proposed as a separated species, bemisia argentifolii, and has recently spread throughout much of the world. when considered with evidence from mating studies and the ability to ... | 1995 | 8595048 |
| characterization of differences between whiteflies using rapd-pcr. | the b biotype of the sweetpotato whitefly, bemisia tabaci (gennadius) has caused over $200 million in crop damage in the us during 1992. the taxonomic classification of the a and b biotypes of b. tabaci is unclear. we used rapd-pcr to demonstrate dna differences between the a and b biotypes of this insect. all twenty of the rapd primers tested distinguished readily between the biotypes. dna extracted from individual eggs and nymphs showed identical differences. rapd-based genetic similarity stat ... | 1993 | 9087541 |
| insect detoxifying enzymes: their importance in pesticide synergism and resistance. | pyrethroid esterases of trichoplusia ni, spodoptera littoralis and bemisia tabaci hydrolyze the trans-isomers of various pyrethroids more extensively than the cis-isomers. profenofos fed to t. ni larvae at a level inhibiting the gut pyrethroid esterases by 65% with trans-permethrin and of 95% with cis-cypermethrin increased the toxicity of topically applied trans-permethrin by fourfold and cis-cypermethrin by 20-fold. similar assays with s. littoralis resulted in an increase of about threefold i ... | 1993 | 8431600 |
| high performance liquid chromatography analysis of carbohydrates of cotton-phloem sap and of honeydew produced by bemisia tabaci feeding on cotton. | phloem sap from cotton (gossypium hirsutum l.) was collected from young and mature leaves by the aphid-stylet technique. exudate was analyzed for carbohydrates by hplc using sensitive pulsed amperometric detection. the predominant carbohydrate present (>90%) was identified as sucrose. a second, unidentified compound that was not one of the more commonly translocated sugars was detected in mature leaves. carbohydrates in honeydew produced by the sweet-potato whitefly (bemisia tabaci [genn.]) feed ... | 1992 | 16668706 |
| spatial analysis of temporal changes in the pandemic of severe cassava mosaic disease in north-western tanzania. | to improve understanding of the dynamics of the cassava mosaic disease (cmd) pandemic front, geospatial approaches were applied to the analysis of three years' data obtained from a 2° by 2° (ca 222km by 222 km) area of north-western tanzania. a total of 80 farmers' fields were assessed in each of 2009, 2010 and 2011, with 20 evenly-distributed fields per 1° by 1° quadrant. cmd-associated variables (cmd incidence, cmd severity, vector-borne cmd infection and vector abundance) increased in magnitu ... | 2017 | 28714353 |
| effects of cucumber mosaic virus - infected chilli plants on non-vector bemisia tabaci (hemiptera: aleyrodidae). | plant virus infections are known to alter host plant attractiveness and suitability for insect herbivores. this study was conducted to determine how cucumber mosaic virus (cmv)-infected chilli plants affect the fitness and settling preferences of non-vector whitefly, bemisia tabaci adults under dual-choice conditions with volatile organic compounds analyzed using solid phase micro-extraction coupled with gas chromatography-mass spectrometry (gc-ms). results showed that the presence of cmv in chi ... | 2017 | 28594105 |
| emergence and epidemiology of cucurbit yellow stunting disorder virus in the american desert southwest, and development of host plant resistance in melon. | cucurbit yellow stunting disorder virus (cysdv), emerged in the sonoran desert region of the southwestern usa in 2006 and has become well established. symptoms induced by cysdv infection include a striking interveinal chlorosis or yellowing and reduced yield and quality. the virus is transmitted by bemisia tabaci, and the cryptic species meam1 has been present in the region since the early 1990s. cysdv has now become the most economically important of the viruses affecting cucurbit production in ... | 2017 | 28595969 |
| insecticide resistance in trialeurodes vaporariorum populations and novel diagnostics for kdr mutations. | neonicotinoids, pyrethroids and ketoenols, are currently used for the control of trialeurodes vaporariorum (hemiptera: aleyrodidae). in this study, insecticide resistance status and mechanisms were investigated by classical bioassays and molecular techniques. | 2017 | 28734106 |
| genetic variability and population structure of the new world begomovirus euphorbia yellow mosaic virus. | the emergence of begomoviruses (whitefly-transmitted viruses classified in the genus begomovirus, family geminiviridae) in brazil probably occurred by horizontal transfer from non-cultivated plants after the introduction of bemisia tabaci meam1. the centre of diversity of euphorbia heterophylla (euphorbiaceae) is located in brazil and paraguay, where it is an invasive species in soybean and other crops. reports of possible begomovirus infection of e. heterophylla in brazil date back to the 1950s ... | 2017 | 28612702 |
| interaction between the new world begomovirus euphorbia yellow mosaic virus and its associated alphasatellite: effects on infection and transmission by the whitefly bemisia tabaci. | the majority of old world monopartite begomoviruses (family geminiviridae) are associated with satellite dnas. alphasatellites are capable of autonomous replication, but depend on the helper virus for movement, encapsidation and transmission by the insect vector. recently, euphorbia yellow mosaic alphasatellite (euyma) was found in association with euphorbia yellow mosaic virus (euymv) infecting euphorbia heterophylla plants in brazil. the geographical range of euyma was assessed in a representa ... | 2017 | 28590236 |
| vector development and vitellogenin determine the transovarial transmission of begomoviruses. | the majority of plant viruses are transmitted by insect vectors between hosts, and transovarial transmission of viruses from vector parents to offspring has great significance to their epidemiology. begomoviruses are transmitted by the whitefly bemisia tabaci in a circulative manner and are maintained through a plant-insect-plant cycle. other routes of begomovirus transmission are not clearly known. here, we report that transovarial transmission from female whiteflies to offspring often happens ... | 2017 | 28607073 |
| a molecular insight into papaya leaf curl-a severe viral disease. | papaya leaf curl disease (palcud) caused by papaya leaf curl virus (palcuv) not only affects yield but also plant growth and fruit size and quality of papaya and is one of the most damaging and economically important disease. management of palcuv is a challenging task due to diversity of viral strains, the alternate hosts, and the genomic complexities of the viruses. several management strategies currently used by plant virologists to broadly control or eliminate the viruses have been discussed. ... | 2017 | 28540512 |
| host-mediated effects of semipersistently transmitted squash vein yellowing virus on sweetpotato whitefly (hemiptera: aleyrodidae) behavior and fitness. | plant viruses may indirectly affect insect vector behavior and fitness via a shared host plant. here, we evaluated the host-mediated effects of squash vein yellowing virus (sqvyv) on the behavior and fitness of its whitefly vector, bemisia tabaci (gennadius) middle east-asia minor 1, formerly biotype b. alighting, settling, and oviposition behavioral assays were conducted on infected and mock-inoculated squash (cucurbita pepo l.) and watermelon [citrullus lanatus (thunb) matsum and nakai] plants ... | 2017 | 28854650 |
| stylet penetration activities of the whitefly bemisia tabaci associated with inoculation of the crinivirus tomato chlorosis virus. | bemisiatabaci is an important vector of numerous plant viruses, including the emergent semi-persistently transmitted crinivirus tomato chlorosis virus (tocv). its vector feeding behaviour is complex, with important implications for virus transmission, epidemiology and control. thus, the objective of this study was to investigate the role of the stylet penetration activities of b. tabaci in the inoculation of tocv in tomatoes by using the electrical penetration graph (epg) technique. epg recordin ... | 2017 | 28613151 |
| transcriptome analysis of the whitefly, bemisia tabaci meam1 during feeding on tomato infected with the crinivirus, tomato chlorosis virus, identifies a temporal shift in gene expression and differential regulation of novel orphan genes. | whiteflies threaten agricultural crop production worldwide, are polyphagous in nature, and transmit hundreds of plant viruses. little is known how whitefly gene expression is altered due to feeding on plants infected with a semipersistently transmitted virus. tomato chlorosis virus (tocv; genus crinivirus, family closteroviridae) is transmitted by the whitefly (bemisia tabaci) in a semipersistent manner and infects several globally important agricultural and ornamental crops, including tomato. | 2017 | 28494755 |
| survey, symptomatology, transmission, host range and characterization of begomovirus associated with yellow mosaic disease of ridge gourd in southern india. | ridge gourd is an important vegetable crop and is affected by several biotic and abiotic factors. among the different biotic factors, ridge gourd yellow mosaic disease (rgymd) is new emerging threat for the production of ridge gourd. the incidence of the rgymd varied from 30 to 100% in southern india with highest disease incidence of 100% observed in belagavi district of karnataka state. the infected plants showed chlorosis, mosaic, cupping of leaves, blistering, reduction in leaf size and stunt ... | 2017 | 28770240 |
| whitefly attraction to rosemary (rosmarinus officinialis l.) is associated with volatile composition and quantity. | whitefly (bemisia tabaci) is an important insect pest, causing severe damage to agricultural crops. the pest was recorded in a commercial rosemary (rosmarinus officinalis, lamiaceae) field, colonizing rosemary variety (var.) '2', but not '11'. a series of field and controlled laboratory choice bioassays confirmed the observed phenomenon. mature potted plants of the two varieties were randomly organized in a lemon verbena (lippia citrodora) and lemon grass (cymbopogon spp.) fields. seven days lat ... | 0 | 28498837 |