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Thrips Species (thrips + species)
Selected AbstractsThe impact of a parasitic nematode, Thripinema fuscum, on the feeding behavior and vector competence of Frankliniella fuscaENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2009Kelly R. Sims Abstract Frankliniella fusca (Hinds) (Thysanoptera: Thripidae) is the predominant thrips species found inhabiting and reproducing in peanut, Arachis hypogaea L. (Fabaceae), and is one of at least seven thrips species reported to transmit Tomato spotted wilt virus (TSWV). The entomogenous nematode Thripinema fuscum Tipping & Nguyen (Tylenchida: Allantonematidae), a natural enemy of F. fusca, parasitizes larval and adult populations under field conditions. All known Thripinema species render the host female thrips sterile and have the potential to suppress pest populations to near extinction. As a result, secondary spread of TSWV in peanut is reduced. Reduction of the virus under field conditions may also be due to lower transmission rates caused by parasite-induced alterations in host feeding behavior. Therefore, the feeding rates of healthy and parasitized F. fusca male and female cohorts on leaf discs were recorded daily for 10 days and digital images were subjected to image analysis and viral transmission rates were compared daily using double antibody sandwich enzyme-linked immunosorbent assay. Thripinema fuscum reduced the feeding of female F. fusca by nearly 65%, and the ability of females to transmit TSWV by 50%. Potential mechanisms underlying the parasite-induced alterations in feeding behavior and transmission are discussed. Parasitism by T. fuscum significantly reduced male longevity, but female longevity was not affected. These results provide further evidence that T. fuscum aids in regulating viruliferous F. fusca pest populations and suggests its potential as a biological control agent for inoculative release in peanut. [source] Real-time PCR assay for the identification of Thrips palmi,EPPO BULLETIN, Issue 1 2005L. F. F. Kox Since Thrips palmi became a regulated pest for most European countries, inspections at points of entry into Europe and monitoring in Europe have intensified not only for T. palmi but also for thrips as a whole. Morphological identification of thrips is performed on adults and to a lesser extent on second-stage larvae only, because no adequate identification keys for the separation of species based on the characteristics of eggs, first-stage larvae, pre-pupae or pupae are available. We have developed a real-time PCR assay based on TaqMan. A T. palmi -specific set of primers and probe were selected within the mitochondrial cytochrome oxidase I (COI) gene. The specificity of the assay was assessed using 15 specimens of Thrips palmi and 61 specimens of 23 other thrips species commonly occuring in Europe. All T. palmi specimens were detected, and no cross reactions with other thrips were observed. The method was tested on single larvae and adults and proved to be applicable for both those stages of T. palmi. [source] Analysis of expressed sequence tags for Frankliniella occidentalis, the western flower thripsINSECT MOLECULAR BIOLOGY, Issue 4 2010D. Rotenberg Abstract Thrips are members of the insect order Thysanoptera and Frankliniella occidentalis (the western flower thrips) is the most economically important pest within this order. F. occidentalis is both a direct pest of crops and an efficient vector of plant viruses, including Tomato spotted wilt virus (TSWV). Despite the world-wide importance of thrips in agriculture, there is little knowledge of the F. occidentalis genome or gene functions at this time. A normalized cDNA library was constructed from first instar thrips and 13 839 expressed sequence tags (ESTs) were obtained. Our EST data assembled into 894 contigs and 11 806 singletons (12 700 nonredundant sequences). We found that 31% of these sequences had significant similarity (E, 10,10) to protein sequences in the National Center for Biotechnology Information nonredundant (nr) protein database, and 25% were functionally annotated using Blast 2GO. We identified 74 sequences with putative homology to proteins associated with insect innate immunity. Sixteen sequences had significant similarity to proteins associated with small RNA-mediated gene silencing pathways (RNA interference; RNAi), including the antiviral pathway (short interfering RNA-mediated pathway). Our EST collection provides new sequence resources for characterizing gene functions in F. occidentalis and other thrips species with regards to vital biological processes, studying the mechanism of interactions with the viruses harboured and transmitted by the vector, and identifying new insect gene-centred targets for plant disease and insect control. [source] Midgut infection by tomato spotted wilt virus and vector incompetence of Frankliniella triticiJOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2005F. M. de Assis Filho Abstract:, The mechanism leading to vector competence of thrips species to transmit tomato spotted wilt virus (TSWV) is not well characterized. We investigated the interaction of TSWV and the non-vector species Frankliniella tritici. A monoclonal antibody to the non-structural protein (NSs) of the TSWV was used to detect TSWV replication within the thrips by immunofluorescence microscopy and enzyme-linked immonosorbent assay (ELISA). TSWV was acquired by F. tritici, replicated and moved within the alimentary canal of F. tritici similar to a known vector of TSWV, Frankliniellaoccidentalis. However, virus was not found in the salivary glands of F. tritici, which is a prerequisite to virus transmission. Thus, movement to the salivary glands may determine vector incompetence of F. tritici. [source] The competence of four thrips species to transmit and replicate four tospovirusesPLANT PATHOLOGY, Issue 2 2004T. Nagata The tospoviruses Tomato spotted wilt virus (TSWV), Tomato chlorotic spot virus (TCSV), Groundnut ringspot virus (GRSV) and Chrysanthemum stem necrosis virus (CSNV) are well-known pathogens on tomato in Brazil. The thrips species Frankliniella occidentalis, F. schultzei, Thrips tabaci and T. palmi were studied for their competence to transmit these tospoviruses. Frankliniella occidentalis transmitted all four tospoviruses with different efficiencies. Frankliniella schultzei transmitted TCSV, GRSV and CSNV. Although F. schultzei has been reported as a vector of TSWV, the F. schultzei population in the present study did not transmit the TSWV isolate used. A population of T. tabaci known to transmit Iris yellow spot virus (onion isolate) did not transmit any of the studied tospoviruses, and nor did T. palmi. Replication of these tospoviruses could be demonstrated by ELISA, not only in the thrips species that could transmit them, but also in those that could not. The results strongly suggest that competence to transmit is regulated not only by the initial amount of virus acquired and replication, but also by possible barriers to virus circulation inside the thrip's body. [source] Identification of Dictyothrips betae as the vector of Polygonum ring spot virusANNALS OF APPLIED BIOLOGY, Issue 2 2010M. Ciuffo Dictyothrips betae (Thysanoptera: Thripidae) is the predominant thrips species on Polygonum convolvulus and Polygonum dumetorum plants infected with a recently described tospovirus species, Polygonum ring spot virus (PolRSV). Laboratory transmission experiments (leaf disk assays) with adults collected directly in the field demonstrated the competence of this thrips to transmit PolRSV, although only at a rate of 4%. However, this increased to 16% using newly emerged larvae fed on infected leaves. Frankliniella occidentalis and Thrips tabaci failed to transmit PolRSV in leaf disk assays. Reverse transcription-polymerase chain reaction (RT-PCR) with specific primers for the N protein and Western blot analysis of adult thrips to detect the N protein confirmed the presence of the virus in D. betae individuals after feeding for at least 5 days on healthy plants. For molecular identification purposes partial sequences of mitochondrial cytochrome c oxidase subunit I (COI), nuclear 28S ribosomal DNA and the elongation factor-1, (EF-1,) from D. betae were cloned. COI sequence was also used for deriving a phylogenetic tree, including D. betae. The results confirmed a relationship between this species and tospovirus-transmitting insects of the genus Thrips. [source] The host range of Tobacco streak virus in India and transmission by thripsANNALS OF APPLIED BIOLOGY, Issue 3 2003R D V J PRASADA RAO Summary Tobacco streak virus (TSV) recently caused an epidemic in peanut (= groundnut, Arachis hypogaea) crops in Andhra Pradesh, India. In the epidemic area TSV occurred in many widely distributed weeds of which Parthenium hysterophorus probably plays a major role in its spread by thrips. Three thrips species, Megalurothrips usitatus, Frankliniella schultzei and Scirtothrips dorsalis were vectors in the presence of infected pollen. Of crop species, Helianthus annuus (sunflower) and Tagetes patula (marigold) could act as sources of inoculum. In limited tests, the virus was not seed-transmitted in the peanut cultivar JL-24 or in the sunflower hybrids KBSH-41, -42, -44, and -50, MSFH-17 and ZSH-976. Strategies adopted to reduce the incidence of TSV are discussed. [source] Diversity of host plant relationships and leaf galling behaviours within a small genus of thrips ,Gynaikothrips and Ficus in south east Queensland, AustraliaAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 4 2009Desley J Tree Abstract Thrips are well known as gall inducers, yet no field studies have been published on phlaeothripids in the genus Gynaikothrips, which gall Ficus leaves in Australia. A detailed field study was conducted in suburban Brisbane, Australia, on thrips species that induce leaf galls on fig trees. Gynaikothrips ficorum is evidently host specific as it induced leaf galls only on Ficus microcarpa, and did so almost continuously throughout the spring and summer growing season. By contrast, G. australis induced leaf galls on F. macrophylla, F. rubingosa and F. obliqua but only when flushes of new leaves appeared, and this occurred at intervals during spring and summer. Gynaikothrips ficorum feeds on the upper surface of new leaves and this causes the leaf to fold and/or twist into a gall. The life of the gall is about 4 weeks, with the thrips pupating within it. Sometimes, the galls are invaded by a kleptoparasite thrips, Mesothrips jordani. Gynaikothrips australis feeds on the underside of the new leaves and this causes the margins to curl under. The life of the gall is about 6 weeks, with the thrips pupating under the bark of the fig tree branches, and sometimes the galls are shared with an inquiline, G. additamentus. [source] Populations of North American bean thrips, Caliothrips fasciatus (Pergande) (Thysanoptera: Thripidae: Panchaetothripinae) not detected in AustraliaAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 2 2006Mark S Hoddle Abstract,Caliothrips fasciatus is native to the USA and western Mexico and overwintering adults are regular contaminants in the ,navel' of navel oranges exported from California, USA to Australia, New Zealand and elsewhere. Due to the long history of regular interceptions of C. fasciatus in Australia, a survey for this thrips was undertaken around airports, seaports, public recreational parks and major agricultural areas in the states of Queensland, New South Wales, Victoria, South Australia and Western Australia to determine whether C. fasciatus has successfully invaded Australia. Host plants that are known to support populations of C. fasciatus, such as various annual and perennial agricultural crops, urban ornamentals and weeds along with native Australian flora, were sampled for this thrips. A total of 4675 thrips specimens encompassing at least 76 species from a minimum of 47 genera, and three families were collected from at least 159 plant species in 67 families. Caliothrips striatopterus was collected in Queensland, but the target species, C. fasciatus, was not found anywhere. An undescribed genus of Thripidae, Panchaetothripinae, was collected from ornamental Grevillea (var. Robyn Gordon) at Perth (Western Australia) Domestic Airport, and is considered to be a native Australian species. This survey has provided valuable information on the background diversity of thrips species associated with various native and exotic plant species around major ports of entry and exit for four of five states in Australia. We suggest that the major reason C. fasciatus has not established in Australia is due to high adult mortality in navels that are kept at low storage temperatures (2.78°C) during an 18- to 24-day transit period from California to Australia. [source] | ||||||||||||||||||||||