Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| tryptophan decarboxylase, tryptamine, and reproduction of the whitefly. | tryptophan decarboxylase (tdc) from catharanthus roseus (periwinkle) converts tryptophan to the indole-alkaloid tryptamine. when the tdc gene was expressed in transgenic tobacco, the 55-kd tdc enzyme and tryptamine accumulated. bemisia tabaci (sweetpotato whitefly) reproduction on transgenic plants decreased up to 97% relative to controls. production of tryptamine, its derivatives, or other products resulting from tdc activity may discourage whitefly reproduction and provide a single-gene-based ... | 1995 | 12228625 |
| 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 |
| nucleotide sequence and phylogenetic analysis of cucurbit yellow stunting disorder virus rna 2. | the complete nucleotide sequence of cucurbit yellow stunting disorder virus (cysdv) rna 2, a whitefly (bemisia tabaci)-transmitted closterovirus with a bi-partite genome, is reported. cysdv rna 2 is 7,281 nucleotides long and contains the closterovirus hallmark gene array with a similar arrangement to the prototype member of the genus crinivirus, lettuce infectious yellows virus (liyv). cysdv rna 2 contains open reading frames (orfs) potentially encoding in a 5' to 3' direction for proteins of 5 ... | 2002 | 12086142 |
| co-adaptation between cassava mosaic geminiviruses and their local vector populations. | four cassava mosaic geminivirus (cmg) isolates; african cassava mosaic virus from namulonge, uganda (acmv-[nam]), east african cassava mosaic virus from mtwara, tanzania (eacmv-[mtw]), eacmv-uganda from namulonge (eacmv-ug[nam]) and indian cassava mosaic virus from trivandrum, india (icmv-[tri]) were compared for their ability to be transmitted by four colonies of cassava whitefly, bemisia tabaci (gennadius), collected from namulonge (nam), mtwara (mtw), kumasi (kum) and trivandrum (tri). with 2 ... | 2002 | 12076831 |
| a distinct bemisia tabaci (gennadius) (hemiptera: sternorrhyncha: aleyrodidae) genotype cluster is associated with the epidemic of severe cassava mosaic virus disease in uganda. | during the 1990s, an epidemic of cassava mosaic virus disease caused major losses to cassava production in uganda. two factors associated with the epidemic were the occurrence of a novel recombinant begomovirus, eacmv-ug, and unusually high populations of the whitefly vector, bemisia tabaci. here we present molecular evidence for the occurrence of two cassava-colonizing b. tabaci genotype clusters, ug1 and ug2, one of which, ug2, can be consistently associated with the cmd epidemic in uganda at ... | 2002 | 12074729 |
| whiteflies (bemisia tabaci) issued from eggs bombarded with infectious dna clones of tomato yellow leaf curl virus from israel (tylcv) are able to infect tomato plants. | we have reported previously that tomato yellow leaf curl virus from israel (tylcv) penetrates the reproductive system of its vector, the whitefly bemisia tabaci biotype b, and may be transmitted to progeny. in order to mimic this phenomenon and to understand how tylcv accompanies the development of the insect, we have bombarded b. tabaci eggs with an infectious dna clone of tylcv. after a linear full-length genomic copy of tylcv dna was delivered to eggs, the dpni-sensitive dna became circular a ... | 2002 | 12038688 |
| evaluation of peracid activated organophosphates in studies of insecticide resistance conferred by insensitive acetylcholinesterases. | peracid activated organophosphorus (op) insecticides were evaluated against electric eel and a range of insect acetylcholinesterases (ache). incubation of chlorpyrifos and sulprofos with meta-chloroperoxybenzoic acid (mcpba) produced active metabolites capable of distinguishing between ache enzymes conferring op susceptibility and resistance in populations of the tobacco whitefly, bemisia tabaci gennadius, and the beet armyworm, spodoptera exigua hubner. these products were also active against e ... | 2002 | 12020023 |
| discovering new insect viruses: whitefly iridovirus (homoptera: aleyrodidae: bemisia tabaci). | adult whiteflies, bemisia tabaci (gennadius), collected from the field were screened for viral pathogens using a cell line from the silverleaf whitefly, b. tabaci, b biotype (syn. b. argentifolii). homogenates from the field-collected whiteflies were applied to cell cultures and checked for cytopathic effects (cpe). cells were observed to develop cytoplasmic inclusions and to have a change in morphology. cells displaying cpe were observed using a transmission electron microscope and found to be ... | 2001 | 12009803 |
| insecticidal 2-hydroxy-3-alkyl-1,4-naphthoquinones: correlation of inhibition of ubiquinol cytochrome c oxidoreductase (complex iii) with insecticidal activity. | the insecticidal and in vitro activities of four homologous series of 2-hydroxy and acetoxy-3-substituted-1,4-naphthoquinones have been measured and correlated with their (log) octanol/water partition coefficients (log ko/w). in vitro activity against mitochondrial complex iii was only exhibited by 2-hydroxy-3-alkyl-1,4-naphthoquinones, indicating that the 2-acetoxy compounds act as proinsecticides. good correlation was observed between in vivo activity against the two-spotted spider mite, tetra ... | 2002 | 11975169 |
| effect of geminivirus infection and bemisia infestation on accumulation of pathogenesis-related proteins in tomato. | the whitefly, bemisia tabaci biotype b, has been shown to cause pathogenesis-related (pr) proteins to accumulate in plants as a result of direct feeding, but their specific role in plant defensive systems is unclear. our objective was to compare accumulation of tomato pr proteins (beta-1,3-glucanase, chitinase, peroxidase, p2 and p4) in response to whitefly, with or without tomato mottle virus (tomov) infection. tomato pr protein response was measured over time in plants divided into three treat ... | 2002 | 11921078 |
| exchange of three amino acids in the coat protein results in efficient whitefly transmission of a nontransmissible abutilon mosaic virus isolate. | geminiviruses are transmitted in a circulative manner by whiteflies, leafhoppers, or treehoppers. the whitefly species bemisia tabaci (genn.) is the vector for members of the genus begomovirus. the closely related bipartite central american begomoviruses abutilon mosaic virus (abmv), sida golden mosaic virus originating from costa rica (sigmv-cr), and sida golden mosaic virus originating from honduras (sigmv-hoyv) were used to study transmission by their insect vector. the abmv isolate is defect ... | 2001 | 11883001 |
| cotton whitefly (bemisia tabaci) resistance to organophosphate and pyrethroid insecticides in pakistan. | resistance to three organophosphate and four pyrethroid insecticides was monitored from 1992 to 2000 in field populations of adult whiteflies, bemisia tabaci, from pakistan using a leaf-dip method. there was generally a very high resistance to dimethoate and deltamethrin, and a moderate resistance to monocrotophos during 1992 to 1996. from 1997 to 2000, resistance to these insecticides dropped to low levels because of less reliance on them for whitefly control, and introduction of new chemistrie ... | 2002 | 11852647 |
| 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 |
| quantitation of cucurbit yellow stunting disorder virus in bemisia tabaci (genn.) using digoxigenin-labelled hybridisation probes. | a cost-efficient hybridisation assay was developed to estimate the amount of cucurbit yellow stunting disorder virus (cysdv) in bemisia tabaci (gennadius) whiteflies infesting protected cucumber crops. cdna from the coat protein (cp) gene and the hsp70 homologue protein gene from cysdv were obtained by reverse transcriptase-pcr from viruliferous whiteflies and cloned into plasmids. digoxigenin (dig)-labelled cdna probes reacted with extracts from these whiteflies applied on nylon membranes. prec ... | 2002 | 11849688 |
| potato yellow mosaic virus: a synonym of tomato yellow mosaic virus. | tomato yellow mosaic was first described in 1963, as a disease caused by a geminivirus transmitted by the whitefly bemisia tabaci in venezuela. in 1981 and 1985, tomato yellow mosaic virus (toymv) was reported to occasionally infect potato plants growing in the proximity of tomato plantings affected by this virus. despite these previous reports, a virus isolated from yellow mosaic-affected potato plants in venezuela, was described in 1986 as a "new geminivirus" called potato yellow mosaic virus ... | 2001 | 11765926 |
| 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 |
| tomato yellow leaf curl china virus: monopartite genome organization and agroinfection of plants. | the complete dna sequence (2734 nucleotides) of the monopartite genome of tomato yellow leaf curl china virus (tylccnv), a begomovirus transmitted by the whitefly bemisia tabaci, was determined. the circular genomic dna contains six open reading frames (orfs) encoding proteins of molecular weights >10 kda, of which two (v1 and v2) are located on the virion-sense strand and four (c1, c2, c3 and c4) on the complementary-sense strand. the orfs are comparable to those of other whitefly-transmitted b ... | 2001 | 11682126 |
| phytoseiid predators as potential biological control agents for bemisia tabaci. | mites of the family phytoseiidae are known to be predators of whiteflies in several agroecosystems, especially of bemisia tabaci gennadius, a pest with high resistance to chemical insecticides that occurs in greenhouses in temperate regions. we collected predatory mites that were found to co-occur with whiteflies in the middle east for control of b. tabaci: tvphlodromus athiasae (porath and swirski), neoseiulus barkeri hughes, tvphlodromips swirskii (athias-henriot), euseius scutalis (athias-hen ... | 2001 | 11603735 |
| encarsia species (hymenoptera: aphelinidae) of australia and the pacific islands attacking bemisia tabaci and trialeurodes vaporariorum (hemiptera: aleyrodidae)--a pictorial key and descriptions of four new species. | after the recent introduction of the pest whitefly bemisia tabaci (gennadius) biotype b into australia, research was undertaken to study the parasitoids of the long established native b. tabaci and trialeurodes vaporariorum (westwood). the genus encarsia contains species which are important biological control agents of whiteflies and hard scales. the taxonomy of the encarsia species attacking b. tabaci and t. vaporariorum in australia and the pacific islands is revised. dna sequencing of the 28s ... | 2001 | 11583600 |
| how species-specific is the phoretic relationship between the broad mite, polyphagotarsonemus latus (acari: tarsonemidae), and its insect hosts? | broad mite, polyphagotarsonemus latus (acari: tarsonemidae), is a serious plant pest in tropical and subtropical regions. phoretic associations between broad mite and two genera of whiteflies (insecta: homoptera: aleyrodidae). namely bemisia and trialeurodes, have been reported from different parts of the world. our purpose was to determine the specificity of the association between the mite and its phoretic hosts. two host plants, potatoes and cucumbers, were used to study these relationships i ... | 2001 | 11523917 |
| molecular characterization of a novel defective dna isolated from tobacco tissues infected with tobacco leaf curl virus. | defective dna of tobacco leaf curl virus (tlcv) was identified in tlcv-infected tobacco plants. the defective dna was cloned and sequenced. the sequence showed it was about half the size of the tlcv dna-a, and was derived from tlcv dna-a by a large deletion. the defective dna contained the intergenic region and part of the ac1 (rep) gene of tlcv, and also novel open reading frames (orfs). the immunotrapping tests showed the defective dna was associated with geminate particles, suggesting it coul ... | 2001 | 11394577 |
| an aphid-borne bacterium allied to the secondary symbionts of whitefly. | bacterial 16s rdna amplified by pcr from the pea aphid acyrthosiphon pisum included a sequence with >98% similarity to secondary symbionts in the whitefly bemisia tabaci. the 'pea aphid bemisia-like bacterium' (pabs) and b. tabaci secondary symbionts are estimated to have diverged 17-34 million years ago, a time considerably more recent than the common ancestor of aphids and whitefly and suggestive of horizontal transmission of this bacterial lineage. pabs was scored in both the gut and ovaries ... | 2001 | 11377772 |
| genetic diversity of iberian populations of bemisia tabaci (hemiptera: aleyrodidae) based on random amplified polymorphic dna-polymerase chain reaction. | the genetic structure of six iberian populations of the whitefly bemisia tabaci, two of them biotype q, one biotype b, and the other three a mixture of both, has been studied using random amplified polymorphic dna-polymerase chain reaction (rapd-pcr). a total of 336 individuals was completely discriminated by means of 234 scored bands. separate analyses of molecular variance of haploid males and diploid females using the pairwise number of differences between haplotypes showed that biotypes cont ... | 2001 | 11348498 |
| 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 |
| alkaline phosphatase activity in whitefly salivary glands and saliva. | alkaline phosphatase activity was histochemically localized in adult whiteflies (bemisia tabaci b biotype, syn. b. argentifolii) with a chromogenic substrate (5-bromo-4-chloro-3-indolylphosphate) and a fluorogenic substrate (elf-97). the greatest amount of staining was in the basal regions of adult salivary glands with additional activity traced into the connecting salivary ducts. other tissues that had alkaline phosphatase activity were the accessory salivary glands, the midgut, the portion of ... | 2001 | 11304750 |
| detection of tomato leaf curl geminivirus in its vector bemisia tabaci. | geminiviruses are single-stranded dna plant infecting viruses that cause major losses in important crops in tropical and subtropical countries. tomato leaf curl virus (tlcv) belonging to the genera begomovirus, is a whitefly-transmitted geminivirus that causes a severe leaf curl disease in tomato (lycopersicon esculentum). the importance of this disease has prompted a great need for a rapid identification of tlcv in its hosts and vector. polymerase chain reaction (pcr) is the most sensitive appr ... | 2000 | 11272420 |
| 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 |
| carbamate and organophosphate resistance in cotton pests in india, 1995 to 1999. | monitoring for organophosphate and carbamate resistance was carried out on five major insect pests of cotton collected from 22 cotton-growing districts across india. resistance was monitored in helicoverpa armigera (hübner) and pectinophora gossypiella (saunders) for the period 1995-1999 and for spodoptera litura (fabricius), earias vittella (fabricius) and bemisia tabaci (gennadius) in a survey conducted during the 1997-98 cropping season. of the 53 field strains of h. armigera, only four were ... | 2001 | 11228586 |
| 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 |
| assessment of insecticide resistance in five insect pests attacking field and vegetable crops in nicaragua. | field populations of hypothenemus hampei (ferrari), plutella xylostella (l.), spodoptera exigua (hübner), helicoverpa zea (boddie) and bemisia tabaci (gennadius) were tested for resistance to several insecticides commonly used in nicariagua. assays were conducted to estimate the ld50s or lc50s and the corresponding resistance ratios. a diagnostic concentration was used to discriminate between susceptible and resistant strains of h. hampei. the tests with >6,000 h. hampei adults collected from si ... | 2000 | 11142313 |
| 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 |
| cotton leaf curl virus disease. | cotton is one of the most important crops of pakistan, accounting for over 60% of foreign exchange earnings. the present epidemic of cotton leaf curl disease (clcud) originated in the punjab region near the city of multan and was first reported in 1985, although it was noted in this region as early as 1967. by the early 1990s, clcud had become the major limitation to cotton production in pakistan and it has now spread into india and, more recently, south and west into other provinces of pakistan ... | 2000 | 11137169 |
| 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 |
| the groel protein of the whitefly bemisia tabaci interacts with the coat protein of transmissible and nontransmissible begomoviruses in the yeast two-hybrid system. | we have previously suggested that a groel homolog produced by the whitefly bemisia tabaci endosymbiotic bacteria interacts in the insect hemolymph with particles of tomato yellow leaf curl virus from israel (tylcv-is), ensuring the safe circulative transmission of the virus. we have now addressed the question of whether the nontransmissibility of abutilon mosaic virus from israel (abmv-is) is related to a lack of association between groel and the virus coat protein (cp). translocation analysis h ... | 2000 | 11040131 |
| variation in the bemisia tabaci s. l. species complex (hemiptera: aleyrodidae) and its natural enemies leading to successful biological control of bemisia biotype b in the usa. | parasitoids of the bemisia tabaci (gennadius) species complex collected in spain and thailand were evaluated as biological control agents of b. tabaci biotype b in cole crops in texas, usa. parasitoids were identified by morphological and rapd-pcr analyses. the most abundant parasitoid from spain was eretmocerus mundus mercet with apparent field parasitism of 39-44%. in thailand, encarsia formosa gahan, e. transvena timberlake, e. adrianae lopez-avila, eretmocerus sp. 1 and sp. 2 emerged, with a ... | 2000 | 11020790 |
| tomato leaf curl virus from bangalore (tolcv-ban4): sequence comparison with indian tolcv isolates, detection in plants and insects, and vector relationships. | tomato leaf curl virus (tolcv) is a whitefly (bemisia tabaci) transmitted geminivirus (family geminiviridae, genus begomovirus) causing a destructive disease of tomato in many regions of india, east asia and australia. while tolcv isolates from australia and taiwan have a single genomic component (designated dna-a), those from northern india have two components (dna-a and dna-b). the tolcv isolates from southern india (bangalore) previously cloned seem to have a dna-a-like monopartite genome. we ... | 2000 | 11003471 |
| host range and symptom variation of pseudorecombinant virus produced by two distinct bipartite geminiviruses. | within the whitefly group only the species bemisia tabaci (gennadius) is the vector. most whitefly-transmitted geminiviruses possess bipartite dna genomes, dnas a and b. although they are closely related to each other, the production of viable pseudorecombinants between bipartite geminiviruses by reassortment of infectious cloned components is generally limited to strains of a particular virus. following exchange of cloned genomic components of sida golden mosaic virus (sigmv/hoyv) and abutilon ... | 2000 | 10963348 |
| cytological and molecular evidence that the whitefly-transmitted cucumber vein yellowing virus is a tentative member of the family potyviridae. | cucumber vein yellowing virus (cvyv) is widespread in cucurbits in the middle east. cvyv has filamentous particles and is transmitted by bemisia tabaci by the semi-persistent mode. it has not yet been assigned to a specific genus or family. ultramicroscopic observations revealed numerous cylindrical cytoplasmic inclusions in melon and cucumber cells infected by cvyv isolates from israel and jordan. depending on the section orientation, the inclusions appeared as pinwheels or as bundles. in addit ... | 2000 | 10950987 |
| variation in tomato host response to bemisia tabaci (hemiptera: aleyrodidae) in relation to acyl sugar content and presence of the nematode and potato aphid resistance gene mi. | two commercial cultivars of tomato, alta and peto 95, the accession line number la716 of lycopersicon pennellii and lines 94gh-006 and 94gh-033 (backcrosses between peto 95 and la716), with different leaf acyl sugar contents were screened for resistance to bemisia argentifolii bellows & perring (corresponding to the spanish b-biotype of bemisia tabaci (gennadius)), in greenhouse- and field-no-choice experiments. there was no oviposition on la716 (with the highest acyl sugar content) while the gr ... | 2000 | 10948376 |
| mating interactions between two biotypes of the whitefly, bemisia tabaci (hemiptera: aleyrodidae) in australia. | the biological consequences of mating interactions between indigenous and exotic biotypes of bemisia tabaci (gennadius) in australia were studied using a combination of field and laboratory experiments. the key results of the interaction between the b and eastern australian biotypes were reduced population increase, a marked increase in the proportion of male progeny, fewer eggs produced by females paired with males of different biotype and no difference in the numbers of eggs per unmated female ... | 2000 | 10948369 |
| 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 |
| tomato yellow leaf curl geminivirus (tylcv-is) is transmitted among whiteflies (bemisia tabaci) in a sex-related manner. | tomato yellow leaf curl virus (tylcv) is the name given to a complex of geminiviruses infecting tomato cultures worldwide. tylcv is transmitted by a single insect species, the whitefly bemisia tabaci. herein we show that a tylcv isolate from israel (tylcv-is) can be transmitted among whiteflies in a sex-dependent manner, in the absence of any other source of virus. tylcv was transmitted from viruliferous males to females and from viruliferous females to males but not among insects of the same se ... | 2000 | 10775612 |
| clones of cotton leaf curl geminivirus induce symptoms atypical of cotton leaf curl disease. | the causative agent of cotton leaf curl disease has previously been shown to be transmissible by the whitefly bemisia tabaci (gennadius) and a begomovirus (geminiviridae) was shown to be associated with the disease. this virus was provisionally called cotton leaf curl virus (clcuv) although no causal relationship between virus and disease was shown. in the present study full-length clones of clcuv, equivalent to the dna a component of bipartite begomoviruses, were obtained. the clones of clcuv w ... | 2000 | 10766303 |
| 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 |
| identification of a novel circular single-stranded dna associated with cotton leaf curl disease in pakistan. | recent reports have suggested that cotton leaf curl virus (clcuv), a geminivirus of the genus begomovirus, may be responsible for cotton leaf curl disease in pakistan. however, the causal agent of the disease remains unclear as clcuv genomic components resembling begomovirus dna a are unable to induce typical disease symptoms when reintroduced into plants. all attempts to isolate a genomic component equivalent to begomovirus dna b have been unsuccessful. here, we describe the isolation and chara ... | 1999 | 10364503 |
| 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 |
| identification of genes directly and indirectly involved in the insect transmission of african cassava mosaic geminivirus by bemisia tabaci. | the inability to transmit progeny virus resulting from the cloned components of an isolate of african cassava mosaic virus originating from kenya (acmv-k) has been shown to be due to defects in both genomic components. this was achieved by the production of infectious pseudorecombinants between acmv-k and the cloned components of a whitefly-transmissible acmv isolate originating from nigeria (acmv-nog). the exchange of gene fragments between acmv-k and acmv-nog has been used to demonstrate that ... | 1999 | 10334034 |
| entomopathogenic potential of verticillium and acremonium species (deuteromycotina: hyphomycetes). | hyphomycetes with conidia formed in slimy heads from hyaline mycelium were isolated from a range of insect hosts. isolation on artificial medium and microscopic examination revealed that these fungi in many cases were not verticillium lecanii despite a superficial resemblance to this common entomopathogen. the fungi were identified as verticillium fusisporum, verticillium psalliotae, verticillium lamellicola, and species of acremonium. isolates of these fungi were bioassayed against the sweet-po ... | 1999 | 10222186 |
| a groel homologue from endosymbiotic bacteria of the whitefly bemisia tabaci is implicated in the circulative transmission of tomato yellow leaf curl virus. | evidence for the involvement of a bemisia tabaci groel homologue in the transmission of tomato yellow leaf curl geminivirus (tylcv) is presented. a approximately 63-kda protein was identified in b. tabaci whole-body extracts using an antiserum raised against aphid buchnera groel. the groel homologue was immunolocalized to a coccoid-shaped whitefly endosymbiont. the 30 n-terminal amino acids of the whitefly groel homologue showed 80% homology with that from different aphid species and groel from ... | 1999 | 10087228 |
| havana tomato virus, a new bipartite geminivirus infecting tomatoes in cuba. | the cloning and nucleotide sequence of a new bipartite geminivirus found in cuba is described. dna a (2620 nt) and dna b (2586 nt) presented a genomic structure resembling that of other geminiviruses transmitted by bemisia tabaci. both components had a common region of 168 nt with a 95% identity. typical elements involved in replication and transcription were found in this region, though group-characteristic arrangement of iterons was not conserved in this virus. sequence was compared with gemin ... | 1998 | 9787659 |
| defective forms of cotton leaf curl virus dna-a that have different combinations of sequence deletion, duplication, inversion and rearrangement. | tobacco and tomato plants inoculated at least 9 months previously with a pakistani isolate of cotton leaf curl virus (clcuv-pk), a whitefly-transmitted geminivirus, contained substantial amounts of circular dsdna molecules that were mostly about half the size of clcuv-pk dsdna-a. they appeared to be derived from clcuv-pk dna-a by various combinations of sequence deletion, duplication, inversion and rearrangement and, in a few instances, insertion of sequences of unknown origin. each of ten tobac ... | 1998 | 9634094 |
| evidence for transovarial transmission of tomato yellow leaf curl virus by its vector, the whitefly bemisia tabaci. | the whitefly bemisia tabaci is the only vector of the tomato yellow leaf curl geminivirus (tylcv). the insect transmits the virus in a persistent-circulative manner. tylcv dna was detected by polymerase chain reaction and by southern blot hybridization in progeny (eggs, first and second instars, adults) of single viruliferous whiteflies that developed on eggplant or on cotton (two tylcv nonhost plants). furthermore, tylcv dna was present in the progeny of insects that had acquired the virus thro ... | 1998 | 9454703 |
| [host plants of bemisia tabaci (homoptera: aleyrodidae) in cuba]. | the sweet potato white fly, bemisia tabaci, is an important pest of tomatoes and beans, among other crops, which transmits viral diseases. since the second quarter of 1989 a significant population increase of this pest has been noted in several cultivated plants. from 1989 to 1992, a survey was done throughout the country, chiefly in vegetable and bean-producing areas. they occur in 119 species (42 families), a great increase over the previous record of four species. worldwide, this report repre ... | 1997 | 9404518 |
| long-term association of tomato yellow leaf curl virus with its whitefly vector bemisia tabaci: effect on the insect transmission capacity, longevity and fecundity. | the association between tomato yellow leaf curl geminivirus (tylcv, israeli isolate) and its insect vector, the whitefly bemisia tabaci, was investigated. insects that emerged during a 24 h period were caged with tylcv-infected plants for a 48 h acquisition access period, then with egg-plants--a tylcv non-host--for the rest of their lives. while tylcv dna was associated with the whiteflies during their entire adult life, the amount of capsid protein rapidly decreased and was not detectable in th ... | 1997 | 9349491 |
| coat protein gene replacement results in whitefly transmission of an insect nontransmissible geminivirus isolate. | geminiviruses are transmitted by whiteflies, leafhoppers, or treehoppers. the whitefly species bemisia tabaci (gennadius) is the most efficient vector of subgroup iii geminiviruses. an isolate of abutilon mosaic virus (abmv), a bipartite geminivirus, was not detectable in the dna extract from insects by southern blot analysis, nor was the isolate transmissible by the b-biotype of b. tabaci, although the virus dna was amplified (by pcr) from some insects. in contrast, sida golden mosaic virus (si ... | 1997 | 9325236 |
| efficient whitefly transmission of african cassava mosaic geminivirus requires sequences from both genomic components. | clones of two subgroup iii geminiviruses, the common strain of tomato golden mosaic virus (cstgmv) and african cassava mosaic virus originating from kenya (acmv-k), were shown to be non-transmissible by whitefiles. lack of transmissibility of cloned acmv-k was investigated by exchanging genomic components with a whitefly-transmissible acmv isolate from nigeria (acmv-nog). neither pseudorecombinant was transmissible, indicating that defects in both genomic components contributed to the lack of tr ... | 1997 | 9225057 |
| 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 |
| 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 |
| engineering resistance against tomato yellow leaf curl virus (tylcv) using antisense rna. | one of the most severe diseases of cultivated tomato worldwide is caused by tomato yellow leaf curl virus (tylcv), a geminivirus transmitted by the whitefly bemisia tabaci. here we describe the application of antisense rnas to interfere with the disease caused by tylcv. the target of the antisense rna is the rare messenger rna of the rep protein, encoded by the c1 gene. transgenic nicotiana benthamiana plants expressing c1 antisense rna were obtained and shown to resist infection by tylcv. some ... | 1997 | 9037152 |
| quantitative determination of tomato yellow leaf curl geminivirus dna by chemiluminescent assay using digoxigenin-labeled probes. | a quantitative dot-blot hybridisation assay was developed for tomato yellow leaf curl geminivirus (tylcv). the assay is based on chemiluminescent detection of viral and plasmid dna using digoxigenin-labeled probes on nylon membranes. the response-error relationship was studied and a square root transformation was found to stabilise the variance of the response. an asymmetric sigmoid (gompertz) curve was used to describe the dose-response relationship. the detection limits and the precision profi ... | 1996 | 8919821 |
| virus-like particles and rickettsia-like organisms in male germ and cyst cells of bemisia tabaci (homoptera, aleyrodidae) | 1996 | 8812613 | |
| virus-like particles in the mycetocytes of the sweetpotato whitefly, bemisia tabaci (homoptera, aleyrodidae). | 1996 | 8812594 | |
| association of geminivirus infection with yellow green mosaic disease of cucumis sativus: diagnosis by nucleic acid probes. | geminivirus association with yellow mosaic disease of c. sativus has been investigated by dot/slot blot hybridization tests using nucleic acid probe derived from dna-b of indian tomato leaf curl geminivirus. the disease was transmitted experimentally on c. sativus by whitefly, bemisia tabaci. some weeds were also found to harbour geminivirus infection in dot/slot blot hybridization tests. | 1996 | 8792653 |
| 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 |
| 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 |
| analysis of the nucleotide sequence of the treehopper-transmitted geminivirus, tomato pseudo-curly top virus, suggests a recombinant origin. | the genome of tomato pseudo-curly top virus (tpctv), originating from florida, has been cloned and sequenced. tpctv is the only geminivirus identified with a vector specificity which falls outside the cicadellidae (leafhoppers) and aleyrodidae (whiteflies). infectivity of the cloned viral genome was demonstrated by agrobacterium-mediated inoculation of several host species. progeny virus was transmissible by the treehopper vector of tpctv, micrutalis malleifera (fowler). the genome of tpctv show ... | 1996 | 8638404 |
| 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 |
| 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 |
| identification of a whitefly species by genomic and behavioral studies. | an introduced whitefly species, responsible for over a half billion dollars in damage to u.s. agricultural production in 1991, is morphologically indistinguishable from bemisia tabaci (gennadius). however, with the use of polymerase chain reaction-based dna differentiation tests, allozymic frequency analyses, crossing experiments, and mating behavior studies, the introduced whitefly is found to be a distinct species. recognition of this new species, the silverleaf whitefly, is critical in the se ... | 1993 | 8418497 |
| replication of tomato yellow leaf curl virus (tylcv) dna in agroinoculated leaf discs from selected tomato genotypes. | the leaf disc agroinoculation system was applied to study tomato yellow leaf curl virus (tylcv) replication in explants from susceptible and resistant tomato genotypes. this system was also evaluated as a potential selection tool in breeding programmes for tylcv resistance. leaf discs were incubated with a head-to-tail dimer of the tylcv genome cloned into the ti plasmid of agrobacterium tumefaciens. in leaf discs from susceptible cultivars (lycopersicon esculentum) tylcv single-stranded genomic ... | 1993 | 8400142 |
| comparative epidemiology of three tropical whitefly-transmitted geminiviruses. | spatial and temporal patterns of spread of african cassava mosaic, okra leaf curl and tobacco leaf curl viruses in west africa, east africa and india share some general characteristics. by comparing the results and running new analyses on available data, it is shown that the epidemiology of these viruses is controlled by the same key variables. for instance, spatial spread is characterised by strong border effects due to accumulation of whitefly vectors (bemisia tabaci) on the wind-exposed field ... | 1993 | 8268255 |
| whitefly transmission and efficient ssdna accumulation of bean golden mosaic geminivirus require functional coat protein. | bean golden mosaic geminivirus (bgmv) has a bipartite genome composed of two circular ssdna components (dna-a and dna-b) and is transmitted by the whitefly, bemisia tabaci. dna-a encodes the viral replication proteins and the coat protein. to determine the role of bgmv coat protein systemic infection and whitefly transmission, two deletions and a restriction fragment inversion were introduced into the bgmv coat protein gene. all three coat protein mutants produced systemic infections when coinoc ... | 1994 | 8091659 |
| polymerase chain reaction detection of viruliferous bemisia tabaci (homoptera: aleyrodidae) with two tomato-infecting geminiviruses. | the sweetpotato whitefly, bemisia tabaci (gennadius), is an important pest worldwide. a new biotype of sweetpotato whitefly, biotype b, causes damage by direct feeding and by the transmission of plant viruses, such as geminiviruses. in the mediterranean area, tomato yellow leaf curl geminivirus (tylcv) is the most serious disease of tomatoes. another whitefly-transmitted geminivirus, tomato mottle geminivirus (tomov), is presently a serious problem in tomato production in west-central and southw ... | 1994 | 7962950 |
| acquisition and transmission of agrobacterium by the whitefly bemisia tabaci. | whiteflies transmit many different plant pathogens. we show here that the whitefly bemisia tabaci can also acquire agrobacterium tumefaciens from liquid cultures and from crown galls, and transmit it to plants. cloned tomato yellow leaf curl virus (tylcv) dna and a. tumefaciens tumor-inducing functions were used as reporter genes. whiteflies were fed through membranes on cultures of agrobacterium at::pty4 containing a dimeric copy of an infectious tylcv genomic clone between the t-dna borders of ... | 1994 | 7873782 |
| biochemical identification of interbreeding between b-type and non b-type strains of the tobacco whitefly bemisia tabaci. | polyacrylamide gel electrophoresis and a kinetic microplate assay were used to detect heterozygotes resulting from a cross between b-type and non b-type strains of the whitefly bemisia tabaci. both strains were homozygous for different esterase and acetylcholinesterase (ache) enzymes, and heterozygotes were produced in one of two crosses between b-type females (diploid) and non b-type males (haploid). in reciprocal crosses, however, no female offspring were produced, indicating that fertilizatio ... | 1995 | 7794236 |
| congruent evolution between whiteflies (homoptera: aleyrodidae) and their bacterial endosymbionts based on respective 18s and 16s rdnas. | whiteflies (family aleyrodidae) possess heritable eubacterial endosymbionts sustained in specialized organ-like structure called mycetomes. comparisons of distances between the ash whitefly, siphoninus phillyreae, and two biotypes ("a" and "b") of the sweetpotato whitefly, bemisia tabaci, based on sequence analysis of genes for 18s rrnas (rdnas), were equivalent to the distances represented by the 16s rdnas of their respective endosymbionts. this finding indicates that evolutionary divergence in ... | 1993 | 7763374 |
| chinese squash leaf curl virus: a new whitefly-transmitted geminivirus. | coat protein (cp) gene of the chinese squash leaf curl virus (sqlcv-c) was amplified through pcr, cloned and completely sequenced. based on the comparisons at the levels of both cp gene nucleotide and cp-deduced amino acid sequences with other geminiviruses, sqlcv-c is confirmed to be distinct from the american squash leaf curl virus (sqlcv-e). it is a new geminivirus transmitted by whitefly bemisia tabaci, which infects dicotyledonous plants and is more closely related to the indian cassava mos ... | 1995 | 7755872 |
| genetic variability of paecilomyces fumosoroseus isolates revealed by molecular markers. | paecilomyces fumosoroseus (deuteromycotina:hyphomycetes) is a fungus that is potentially useful for the bio-control of economically important agricultural pests, such as whitefly (bemisia tabaci). arbitrarily primed pcr and pcr with trna consensus primers were used to analyze genetic variability among 27 p. fumosoroseus isolates, 15 of which came from the same host, b. tabaci, one p. lilacinus isolate, used as an outgroup, 9 previously unidentified paecilomyces isolates. fifteen 10-mer oligonucl ... | 1995 | 7745282 |
| the occurrence in the body of bemisia tabaci of a factor apparently related to the phenomenon of "periodic acquisition" of tomato yellow leaf curl virus. | 1967 | 6017403 | |
| the nucleotide sequence of abutilon mosaic virus reveals prokaryotic as well as eukaryotic features. | the complete nucleotide sequence of abutilon mosaic virus (west indian isolate, abmva) is presented. the resulting genomic structure resembles that of other geminiviruses which are transmitted by the whitefly bemisia tabaci: abmv possesses a bipartite circular genome with bidirectional orientation of the open reading frames (orf). both components have a common region of 180 bases with 99% homology while the rest of their sequence is distinct. eukaryotic regulatory transcription elements precede ... | 1990 | 2219703 |
| acquisition of tomato yellow leaf curl virus by the whitefly bemisia tabaci. | tomato yellow leaf curl virus (tylcv) genomic dna can be detected by southern blot analysis in nucleic acid extracted from a single whitefly. acquisition of tylcv by individual whiteflies in relation to the length of the access period, the virus concentration in, and the developmental stage of plant tissues was studied. the frequency of tylcv detection increased with the length of the access-period; dna was detected in 15% of whiteflies tested after a period of access to infected tissue of 30 mi ... | 1991 | 1940856 |
| tomato yellow leaf curl virus: a whitefly-transmitted geminivirus with a single genomic component. | the genome of the tomato yellow leaf curl virus (tylcv), a bemisia tabaci-transmitted geminivirus, was cloned. all clones obtained were of one genomic molecule, analogous to dna a of african cassava mosaic virus. nucleotide sequence analysis of the tylcv genome showed that it comprises 2787 nucleotides, encoding six open reading frames, two on the virion strand and four on the complementary strand. all of them have counterparts in other geminiviruses. dimeric copies of the cloned viral genome we ... | 1991 | 1926771 |
| tomato yellow leaf curl virus from sardinia is a whitefly-transmitted monopartite geminivirus. | the genome of an isolate of tomato yellow leaf curl virus from sardinia, italy (tylcv-s), a geminivirus transmitted by the whitefly bemisia tabaci, has been cloned and sequenced. the single circular dna molecule comprises 2770 nucleotides. genome organisation closely resembles that of the dna a component of the whitefly-transmitted geminiviruses with a bipartite genome. a 1.8 mer of the tylcv-s genome in a binary vector of agrobacterium tumefaciens is infectious upon agroinoculation of tomato pl ... | 1991 | 1840676 |
| use of digoxigenin-labelled probes for detection and host-range studies of tomato yellow leaf curl geminivirus. | we studied the host range of tomato yellow leaf curl virus (tylcv) in some agronomically important tomato species. transmission tests with the natural vector bemisia tabaci from tomato to sweet pepper, eggplant, cucumber, melon, zucchini and spinach showed that these species did not develop symptoms and did not support viral replication. these species therefore do not constitutive a reservoir of the virus and can be cultivated as alternatives to tomato in the most affected areas. for host-range ... | 1991 | 1796214 |