The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
D Peters - One of the best experts on this subject based on the ideXlab platform.
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tomato spotted wilt virus infection improves host suitability for its vector Frankliniella occidentalis
Phytopathology, 2004Co-Authors: P C Maris, N N Joosten, Rob Goldbach, D PetersAbstract:ABSTRACT The effect of Tomato spotted wilt virus (TSWV) infection on plant attractiveness for the western flower thrips (Frankliniella occidentalis) was studied. Significantly more thrips were recovered on infected than were recovered on noninfected pepper (Capsicum annuum) plants in different preference tests. In addition, more offspring were produced on the virus-infected pepper plants, and this effect also was found for TSWV-infected Datura stramonium. Thrips behavior was minimally influenced by TSWV-infection of host plants with only a slight preference for feeding on infected plants. Offspring development was positively affected since larvae hatched earlier from eggs and subsequently pupated faster on TSWV-infected plants. These results show a mutualistic relationship between F. occidentalis and TSWV.
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tomato spotted wilt tospovirus ingestion by first instar larvae of Frankliniella occidentalis is a prerequisite for transmission
Phytopathology, 1996Co-Authors: F Van De Wetering, R Goldbach, D PetersAbstract:Tomato spotted wilt tospovirus (TSWV) is, after ingestion by first instar larvae, efficiently transmitted by second instar larvae and adults of the thrips Frankliniella occidentalis in a propagative manner. The developmental stage at which thrips larvae acquire an infectious dose, resulting in adults that can transmit the virus, is further defined. TSWV accumulation and transmission occurred after ingestion by first instar larvae. Second instar larvae failed to acquire and retain TSWV upon ingestion and did not develop into transmitters. No correlation was found between the quantity of TSWV ingested by thrips and their ability to acquire TSWV. Instead, first instar larvae gradually lost their acquisition ability with increasing age, suggesting the development of a barrier preventing TSWV acquisition and, consequently, replication needed for transmission. The finding that TSWV is acquired exclusively by first instar larvae of F occidentalis is of crucial importance for understanding the epidemiology of this devastating virus.
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determination of the median latent period of two tospoviruses in Frankliniella occidentalis using a novel leaf disk assay
Phytopathology, 1993Co-Authors: I. Wijkamp, D PetersAbstract:A novel assay system, based on the use of the local lesion host Petunia×hybrida, was developed for studying the transmission of tospoviruses by the thrips Frankliniella occidentalis. Efficient transmission was obtained for two different tospoviruses, tomato spotted wilt virus (TSWV) and impatiens necrotic spot virus (INSV), reaching rates up to 55.1 and 92.5%, respectively. Because the majority of the thrips became viruliferous in the second larval stage, the median latent period (LP 50 ) was determined for this stage. The LP 50 values decreased with increasing temperatures. For INSV, the LP 50 values were 157, 103, and 82 h at 20, 24, and 27 C, respectively, and for TSWV, they were 171, 109, and 84 h at the respective temperatures
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multiplication of tomato spotted wilt virus in its insect vector Frankliniella occidentalis
Journal of General Virology, 1993Co-Authors: I. Wijkamp, J W M Van Lent, Richard Kormelink, R W Goldbach, D PetersAbstract:The accumulation of two proteins, the nucleocapsid (N) protein and a non-structural (NSs) protein both encoded by the S RNA of tomato spotted wilt virus (TSWV), was followed in larvae during development and in adults of Frankliniella occidentalis after ingesting the virus for short periods on infected plants. The amounts of both proteins increased, as shown by ELISA and Western blot analysis, within 2 days above the levels ingested, indicating multiplication of TSWV in these insects. Accumulation of these proteins and of virus particles was further confirmed by in situ immunolabelling of the salivary glands and other tissues of adult thrips. The accumulation of large amounts of N and NSs protein, the occurrence of several vesicles with virus particles in the salivary glands and the massive numbers of virus particles in the salivary gland ducts demonstrate that the salivary glands are a major site of TSWV replication. The occurrence of virus particles in the salivary vesicles is indicative of the involvement of the Golgi apparatus in the maturation of the virus particles and its transport to the salivary ducts.
Scott Adkins - One of the best experts on this subject based on the ideXlab platform.
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role of the insect supervectors bemisia tabaci and Frankliniella occidentalis in the emergence and global spread of plant viruses
Annual Review of Virology, 2015Co-Authors: R L Gilbertson, Ozgur Batuman, Craig G Webster, Scott AdkinsAbstract:Emergence of insect-transmitted plant viruses over the past 10–20 years has been disproportionately driven by two so-called supervectors: the whitefly, Bemisia tabaci, and the Western flower thrips, Frankliniella occidentalis. High rates of reproduction and dispersal, extreme polyphagy, and development of insecticide resistance, together with human activities, have made these insects global pests. These supervectors transmit a diversity of plant viruses by different mechanisms and mediate virus emergence through local evolution, host shifts, mixed infections, and global spread. Associated virus evolution involves reassortment, recombination, and component capture. Emergence of B. tabaci–transmitted geminiviruses (begomoviruses), ipomoviruses, and torradoviruses has led to global disease outbreaks as well as multiple paradigm shifts. Similarly, F. occidentalis has mediated tospovirus host shifts and global dissemination and the emergence of pollen-transmitted ilarviruses. The plant virus–supervector intera...
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role of the insect supervectors bemisia tabaci and Frankliniella occidentalis in the emergence and global spread of plant viruses
Annual Review of Virology, 2015Co-Authors: R L Gilbertson, Ozgur Batuman, Craig Webster, Scott AdkinsAbstract:Emergence of insect-transmitted plant viruses over the past 10-20 years has been disproportionately driven by two so-called supervectors: the whitefly, Bemisia tabaci, and the Western flower thrips, Frankliniella occidentalis. High rates of reproduction and dispersal, extreme polyphagy, and development of insecticide resistance, together with human activities, have made these insects global pests. These supervectors transmit a diversity of plant viruses by different mechanisms and mediate virus emergence through local evolution, host shifts, mixed infections, and global spread. Associated virus evolution involves reassortment, recombination, and component capture. Emergence of B. tabaci-transmitted geminiviruses (begomoviruses), ipomoviruses, and torradoviruses has led to global disease outbreaks as well as multiple paradigm shifts. Similarly, F. occidentalis has mediated tospovirus host shifts and global dissemination and the emergence of pollen-transmitted ilarviruses. The plant virus-supervector interaction offers exciting opportunities for basic research and global implementation of generalized disease management strategies to reduce economic and environmental impacts.
I. Wijkamp - One of the best experts on this subject based on the ideXlab platform.
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determination of the median latent period of two tospoviruses in Frankliniella occidentalis using a novel leaf disk assay
Phytopathology, 1993Co-Authors: I. Wijkamp, D PetersAbstract:A novel assay system, based on the use of the local lesion host Petunia×hybrida, was developed for studying the transmission of tospoviruses by the thrips Frankliniella occidentalis. Efficient transmission was obtained for two different tospoviruses, tomato spotted wilt virus (TSWV) and impatiens necrotic spot virus (INSV), reaching rates up to 55.1 and 92.5%, respectively. Because the majority of the thrips became viruliferous in the second larval stage, the median latent period (LP 50 ) was determined for this stage. The LP 50 values decreased with increasing temperatures. For INSV, the LP 50 values were 157, 103, and 82 h at 20, 24, and 27 C, respectively, and for TSWV, they were 171, 109, and 84 h at the respective temperatures
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multiplication of tomato spotted wilt virus in its insect vector Frankliniella occidentalis
Journal of General Virology, 1993Co-Authors: I. Wijkamp, J W M Van Lent, Richard Kormelink, R W Goldbach, D PetersAbstract:The accumulation of two proteins, the nucleocapsid (N) protein and a non-structural (NSs) protein both encoded by the S RNA of tomato spotted wilt virus (TSWV), was followed in larvae during development and in adults of Frankliniella occidentalis after ingesting the virus for short periods on infected plants. The amounts of both proteins increased, as shown by ELISA and Western blot analysis, within 2 days above the levels ingested, indicating multiplication of TSWV in these insects. Accumulation of these proteins and of virus particles was further confirmed by in situ immunolabelling of the salivary glands and other tissues of adult thrips. The accumulation of large amounts of N and NSs protein, the occurrence of several vesicles with virus particles in the salivary glands and the massive numbers of virus particles in the salivary gland ducts demonstrate that the salivary glands are a major site of TSWV replication. The occurrence of virus particles in the salivary vesicles is indicative of the involvement of the Golgi apparatus in the maturation of the virus particles and its transport to the salivary ducts.
R L Gilbertson - One of the best experts on this subject based on the ideXlab platform.
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role of the insect supervectors bemisia tabaci and Frankliniella occidentalis in the emergence and global spread of plant viruses
Annual Review of Virology, 2015Co-Authors: R L Gilbertson, Ozgur Batuman, Craig G Webster, Scott AdkinsAbstract:Emergence of insect-transmitted plant viruses over the past 10–20 years has been disproportionately driven by two so-called supervectors: the whitefly, Bemisia tabaci, and the Western flower thrips, Frankliniella occidentalis. High rates of reproduction and dispersal, extreme polyphagy, and development of insecticide resistance, together with human activities, have made these insects global pests. These supervectors transmit a diversity of plant viruses by different mechanisms and mediate virus emergence through local evolution, host shifts, mixed infections, and global spread. Associated virus evolution involves reassortment, recombination, and component capture. Emergence of B. tabaci–transmitted geminiviruses (begomoviruses), ipomoviruses, and torradoviruses has led to global disease outbreaks as well as multiple paradigm shifts. Similarly, F. occidentalis has mediated tospovirus host shifts and global dissemination and the emergence of pollen-transmitted ilarviruses. The plant virus–supervector intera...
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role of the insect supervectors bemisia tabaci and Frankliniella occidentalis in the emergence and global spread of plant viruses
Annual Review of Virology, 2015Co-Authors: R L Gilbertson, Ozgur Batuman, Craig Webster, Scott AdkinsAbstract:Emergence of insect-transmitted plant viruses over the past 10-20 years has been disproportionately driven by two so-called supervectors: the whitefly, Bemisia tabaci, and the Western flower thrips, Frankliniella occidentalis. High rates of reproduction and dispersal, extreme polyphagy, and development of insecticide resistance, together with human activities, have made these insects global pests. These supervectors transmit a diversity of plant viruses by different mechanisms and mediate virus emergence through local evolution, host shifts, mixed infections, and global spread. Associated virus evolution involves reassortment, recombination, and component capture. Emergence of B. tabaci-transmitted geminiviruses (begomoviruses), ipomoviruses, and torradoviruses has led to global disease outbreaks as well as multiple paradigm shifts. Similarly, F. occidentalis has mediated tospovirus host shifts and global dissemination and the emergence of pollen-transmitted ilarviruses. The plant virus-supervector interaction offers exciting opportunities for basic research and global implementation of generalized disease management strategies to reduce economic and environmental impacts.
Pablo Bielza - One of the best experts on this subject based on the ideXlab platform.
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cross resistance and baseline susceptibility of spirotetramat in Frankliniella occidentalis thysanoptera thripidae
Journal of Economic Entomology, 2014Co-Authors: Juan Guillen, Miguel Navarro, Pablo BielzaAbstract:Western flower thrips, Frankliniella occidentalis (Pergande), is an economically important pest all over the world. New products against thrips are necessary, as there are few effective compounds exhibiting cross-resistance among them. Lethal effects, cross-resistance, and baseline susceptibility to spirotetramat were evaluated in this study. A new bioassay method for testing thrips against spirotetramat was developed. Spirotetramat showed a significant mortality effect on larvae after 7 d of exposure, but a low effect was observed on adults. Baseline results for larval instars showed LC50 values ranging from 11.59 to 49.81 mg AI/liter, with a low natural variability (3.2-fold). Cross-resistance studies showed overlapping confidence limits of the LC50 values for laboratory-selected (against acrinathrin, methiocarb, formetanate, and spinosad) resistant and susceptible strains, and low resistance factors, from 0.5 to 1.9, suggesting no cross-resistance to conventional insecticides previously used. A slight ovicidal effect (21-40% reduction) was also detected. Despite presenting low effects on adults, spirotetramat showed high but slow efficacy on F. occidentalis larvae. Field populations in southeast Spain showed a consistent susceptibility to spirotetramat. Given the scarcity of effective products and the lack of cross-resistance to other insecticides, spirotetramat can be considered as a good chemical tool to control F. occidentalis.
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insecticide resistance management strategies against the western flower thrips Frankliniella occidentalis
Pest Management Science, 2008Co-Authors: Pablo BielzaAbstract:Western flower thrips (WFT), Frankliniella occidentalis (Pergande), is an economically important pest of a wide range of crops grown throughout the world. Insecticide resistance has been documented in many populations of WFT. Biological and behavioural characteristics and pest management practices that promote insecticide resistance are discussed. In addition, an overview is provided of the development of insecticide resistance in F. occidentalis populations and the resistance mechanisms involved. Owing to widespread resistance to most conventional insecticides, a new approach to insecticide resistance management (IRM) of F. occidentalis is needed. The IRM strategy proposed consists of two parts. Firstly, a general strategy to minimise the use of insecticides in order to reduce selection pressure. Secondly, a strategy designed to avoid selection of resistance mechanisms, considering cross-resistance patterns and resistance mechanisms.
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genetics of spinosad resistance in Frankliniella occidentalis thysanoptera thripidae
Journal of Economic Entomology, 2007Co-Authors: Pablo Bielza, V Quinto, E Fernandez, C Gravalos, J ContrerasAbstract:The genetic basis of spinosad resistance was investigated in the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). The resistant strain, selected in the laboratory for spinosad resistance from a pool of thrips populations collected in Almeria (southeastern Spain), showed a very high resistance to spinosad (356,547-fold based on LC50 values) compared with the laboratory susceptible strain. Mortality data from reciprocal crosses of resistant and susceptible thrips indicated that resistance was autosomal and not influenced by maternal effects. Analysis of probit lines from the parental strains and reciprocal crosses showed that resistance was expressed as an almost completely recessive trait. To determine the number of genes involved, a direct test of monogenic inheritance based on the backcrosses suggested that resistance to spinosad was probably controlled by one locus. Another approach, which was based on phenotypic variances, showed that nE, or the minimum number of freely segregating genetic factors for the resistant strain, equaled 0.59.
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metabolic mechanisms of insecticide resistance in the western flower thrips Frankliniella occidentalis pergande
Pest Management Science, 2005Co-Authors: Pedro J Espinosa, V Quinto, E Fernandez, C Gravalos, J Contreras, Pablo BielzaAbstract:The interactions between six insecticides (methiocarb, formetanate, acrinathrin, deltamethrin, methamidophos and endosulfan) and three potential synergists (piperonyl butoxide (PBO), S,S,S-tributyl phosphorotrithioate (DEF) and diethyl maleate (DEM)) were studied by topical exposure in strains selected for resistance to each insecticide, and in a susceptible strain of Frankliniella occidentalis (Pergande). In the susceptible strain PBO produced appreciable synergism only of formetanate, methiocarb and methamidophos. Except for endosulfan, PBO synergized all the insecticides to varying degrees in the resistant strains. A very high level of synergism by PBO was found with acrinathrin, which reduced the resistance level from 3344- to 36-fold. PBO slightly synergized the carbamates formetanate (4.6-fold) and methiocarb (3.3-fold). PBO also produced a high synergism of deltamethrin (12.5-fold) and methamidophos (14.3-fold) and completely restored susceptibility to both insecticides. DEF did not produce synergism with any insecticide in the resistant strains and DEM was slightly synergistic to endosulfan (3-fold). These studies indicate that an enhanced detoxification, mediated by cytochrome P-450 monooxygenases, is the major mechanism imparting resistance to different insecticides in F occidentalis. Implications of different mechanisms in insecticide resistance in F occidentalis are discussed.
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Field and laboratory selection of Frankliniella occidentalis (Pergande) for resistance to insecticides
Pest Management Science, 2002Co-Authors: Pedro J Espinosa, Pablo Bielza, Josefina Contreras, Alfredo LacasaAbstract:Response of western flower thrips, Frankliniella occidentalis (Pergande), to selection for resistance to insecticides commonly used to control this pest in Murcia (south-east Spain) was studied under field and laboratory conditions. In the field, plots within sweet pepper crops in commercial and experimental greenhouses were treated under different selection strategies: insecticide rotation versus formetanate reiteration, formetanate reiteration versus acrinathrin reiteration, and formetanate reiteration versus methiocarb reiteration. Thrips populations were sampled monthly and bioassayed against methiocarb, methamidophos, acrinathrin, endosulfan, deltamethrin and formetanate. In the laboratory, F occidentalis strains were selected against each insecticide for several generations. To evaluate cross-resistance, each selected strain was bioassayed with the other insecticides. Frankliniella occidentalis populations showed a rapid development of acrinathrin resistance, reaching high levels in field and laboratory conditions. Formetanate and methiocarb resistance were also observed, although development was slower and at moderate levels. Cross-resistances between acrinathrin/ deltamethrin and acrinathrin/formetanate were detected under field and laboratory conditions. Formetanate/methiocarb cross-resistance was suspected in laboratory selections, but not in field assays. Simultaneous moderate resistance levels to the three specific insecticides against thrips (formetanate, methiocarb and acrinathrin) were shown in laboratory selection strains, indicating a general mechanism of resistance, probably metabolic.
