Thrips are among the most important agricultural pests globally because of the damage inflicted by their oviposition, feeding, and ability to transmit plant viruses. Because of their invasiveness, a number of pest spe...Thrips are among the most important agricultural pests globally because of the damage inflicted by their oviposition, feeding, and ability to transmit plant viruses. Because of their invasiveness, a number of pest species are common to both China and the United States and present significant challenges to growers of a wide range of crops in both countries. Among the pest thrips common to both countries are four of the major global thrips pests, Frankliniella occidentalis （Pergande）, Scirtothrips dorsalis Hood, Thrips palmi Karny, and Thrips tabaci Lindeman. This review addresses characteristics that enable thrips to be such damaging pests and how biological attributes of thrips create challenges for their management. Despite these challenges, a number of successful management tactics have been developed for various cropping systems. We discuss some of these tactics that have been developed, including the use of cultural controls, biological controls, and judicious use of insecticides that do not disrupt overall pest management programs. The exchange of this type of information will help to facilitate management of pest thrips, especially in regions where species have recently invaded. A prime example is F. occidentalis, the western flower thrips, which is native to the United States, but has recently invaded China. Therefore, management tactics developed in the United States can be adapted to China. Because further success in management of thrips requires a thorough understanding of thrips ecology, we discuss areas of future research and emphasize the importance of collaboration among different countries to enhance our overall understanding of the biology and ecology of thrips and to improve management programs for these widespread pests.展开更多
The westem flower thrips, Frankliniella occidental＆ （Pergande） is a highly invasive pest that is able to exploit many crops across a wide range of environmental conditions. Five full-length cDNAs of heat shock prot...The westem flower thrips, Frankliniella occidental＆ （Pergande） is a highly invasive pest that is able to exploit many crops across a wide range of environmental conditions. Five full-length cDNAs of heat shock protein （HSP） genes （Fo-HSP90, Fo-HSP70, Fo-HSP60, Fo-HSP40 and Fo-HSP28.9） were cloned from F. occidentalis, and their expression profiles were investigated under conditions of thermal stress and insecticide exposure, and at different stages during development, using real-time quantitative PCR. All five gene sequences showed high similarity to homologs in other species, indicating the conserved fimction of this gene family. HSP60 represents an informative phylogenetic marker at the ordinal taxonomic level within Insecta, but HSP90, which has two homologous copies in Hymenoptera, was not informative. The expression of Fo-HSPs under thermal stress suggests that Fo-HSP90, Fo-HSP70, and Fo-HSP28.9 are inducible by both cold and heat stress, Fo-HSP40 is only heat-inducible, and Fo-HSP60 is thermally insensitive. There were two patterns of cold induction of Fo-HSPs： one is from 0 to 4℃ and the other is around -8℃. All five Fo-HSPs genes were induced by exposure to sublethal concentrations of the insecticide avermectin. The expression of the five Fo-HSPs during different developmental stages suggests that they all play a role in development of F. occidentalis.展开更多
The western flower thrips, Frankliniella occidentalis, is one of the most destructive sucking pests of vegetables, fruits and ornamental crops in China. Spinosad is one of the most commonly used insecticides to manage...The western flower thrips, Frankliniella occidentalis, is one of the most destructive sucking pests of vegetables, fruits and ornamental crops in China. Spinosad is one of the most commonly used insecticides to manage thrips. To assess the incidence of spinosad resistance in F. occidentalis field populations in eastern China, survival rates for 24 different populations were compared with those of a susceptible laboratory strain. All populations showed significantly higher resistance to spinosad compared with the control as determined by comparing median lethal concentrations. Two populations from Shouguang and Liaocheng in Shandong Province were classified as having moderate and high levels of resistance to spinosad with a mean resistance ratio of 17.0 and 89.2, respectively. Our research indicates a widespread reduction in spinosad efficacy for controlling F. occidentalis field populations, and that resistance management strategies should be implemented as soon as practicable, to reduce the potential of progressive resistance development and loss of efficacy.展开更多
The daily flight activity of westem flower thrips, Frankliniella occidentalis （Pergande） （Thysanoptera： Thripidae） was examined using color, yellow-light and chemical attractant traps in a cucumber greenhouse and...The daily flight activity of westem flower thrips, Frankliniella occidentalis （Pergande） （Thysanoptera： Thripidae） was examined using color, yellow-light and chemical attractant traps in a cucumber greenhouse and under controlled laboratory conditions. In the greenhouse, flying thrips were most abundant between hours 08：00-10：00, declined at mid-day, and then slightly increased during hours 14：00-16：00; however they decreased to a very low level at 18：00. The use of light traps showed no thrip flight activity during the night. The total number of thrips that flew onto cards on rainy or cloudy days was higher than that on sunny days. We reconfirmed that traps treated with attractant attracted 4.0-9.4 times more thrip than the untreated traps. Under laboratory controlled conditions, thrip flight activity was highest under light intensity between 4 000 and 6 000 lux, air temperature of 28℃, and RH of 70%. In addition, starved thrips flew more readily than non-starved thrips.展开更多
Heat shock protein 70（HSP70） is one of the most important members in the heat shock protein family, and plays important roles in the thermotolerance of insect. To explore the molecular mechanism of thermotolerance o...Heat shock protein 70（HSP70） is one of the most important members in the heat shock protein family, and plays important roles in the thermotolerance of insect. To explore the molecular mechanism of thermotolerance of Frankliniella occidentalis adults, the difference in the expression of HSP70s in F. occidentalis male or female adults under the thermal stress was studied under the laboratory conditions. Two full length c DNAs of HSP70s gene（Fohsc704 and Fohsc705） were cloned from F. occidentalis by using RT-PCR and RACE. The genomic sequence was demonstrated by genomic validation, and the position and size of the intron were analyzed by sequence analysis of c DNA. Real-time PCR was used to analyze the HSP70 expression patterns. The c DNA of Fohsc704 and Fohsc705 possessed 2 073 and 1 476 bp which encoded 690 and 491 amino acids（aa） with a calculated molecular weight of 75 and 54 k Da, respectively. Four introns in Fohsc704 and six introns in Fohsc705 protein were found. However, the HSP70 protein sequences in our study were ended with EKKN and GIFL, which were different from the reported Fo HSP70s. Various expression patterns of Fohsc704 and Fohsc705 were found in both genders of F. occidentalis under thermal stress. The expression of Fohsc704 and Fohsc705 reached to the highest level at –12 and –8°C in male adults, respectively, and Fohsc705 expressed the highest level at 33°C in female adults. In conclusion, HSP70s of F. occidentalis in our study are novel heat shock proteins. There were difference in expression patterns of the two hsc70s in genders of F. occidentalis, and the two HSP70s play important roles in the thermotolerance of F. occidentalis.展开更多
Impatiens necrotic spot virus( INSV) is an important plant virus identified in recent years. Western flower thrip( Frankliniella occidentalis) has been confirmed to be the most efficient vector for INSV. In the presen...Impatiens necrotic spot virus( INSV) is an important plant virus identified in recent years. Western flower thrip( Frankliniella occidentalis) has been confirmed to be the most efficient vector for INSV. In the present study,Illumina's second-generation sequencing technique was used to determine the variation in gene expression at the transcriptome level in western flower thrip before and after infection with INSV. By aligning 168 188 unigenes of western flower thrip to the NCBI protein database,47 558 unigenes were annotated,accounting for 28. 27% of the total. Species classification revealed that 58. 7% of the annotated unigenes of western flower thrip did not match any other species,and 15. 4% of had a match in Zootermopsis navadensis,12. 4% in Mus musculus,7. 3% in Mustela putorius,3. 4% in Theileria parva,and 2. 7% in Tribolium castaneum. By analyzing DEGs between INSV-free and INSV-carrying western flower thrips,we found that 11 genes were upregulated,and 9 genes were downregulated in western flower thrip after INSV infection. In addition,cell cycle and ubiquitin-proteasome pathway in western flower thrip were significantly infected by INSV infection.展开更多
[Objective] The paper was to explore the chemical and molecular mechanisms of Frankliniella occidentalis, an important quarantine pest, against toxic substances. [Method] F. occidentalis were evaluated after continuou...[Objective] The paper was to explore the chemical and molecular mechanisms of Frankliniella occidentalis, an important quarantine pest, against toxic substances. [Method] F. occidentalis were evaluated after continuous exposure to artificial diets containing nicotine from the 2^（nd） and the 3^（rd）instars for five generations, to determine the larval weight, pupal weight, and larval development duration. [Result] The larval development delayed and nicotine treatment significantly inhibited the weight gain of larvae. Compared to the control, the inhibition rates of larval weight and pupal weight were declined from 45% to 20% and from 25% to 4% respectively after feeding the 2^（nd）instars with nicotine for five generations.Nicotine delayed the larval growth and prolonged the generation duration of F. occidentalis. Nicotine showed more significant inhibitory effect on the lower instar larvae. With the increasing generations of secondary culture, the inhibitory effect of nicotine on larval weight and pupal weight was weakened. The developmental period of larvae was shortened, and the generation duration of F. occidentalis was shortened. [Conclusion] Nicotine affects the growth and development of F. occidentalis. F. occidentalis will gradually increase the adaptability to nicotine toxic substances after selfregulation for a few generations, and relieve the inhibitory effect of toxic substances.展开更多
This study investigated the olfactory responses of 3 thrips species [Frankliniella schultzei Trybom, E occidentalis Pergrande and Thrips tabaci Lindeman （Thysanoptera： Thripidae）] to cotton seedlings [Gossypium hir...This study investigated the olfactory responses of 3 thrips species [Frankliniella schultzei Trybom, E occidentalis Pergrande and Thrips tabaci Lindeman （Thysanoptera： Thripidae）] to cotton seedlings [Gossypium hirsutum L. （Malvales： Malvaceae）] simulta- neously damaged by different combinations of herbivores. Cotton seedlings were damaged by foliar feeding Tetranychus urticae Koch （Trombidiforms： Tetranychidae）, Helicoverpa armigera Hibner （Lepidoptera： Noctuidae）, Aphis＇ gossypii Glover （Hemiptera： Aphidi- dae） or root feeding Tenebrio molitor L. （Coleoptera： Tenebrionidae）. Thrips responses to plants simultaneously damaged by 2 species of herbivore were additive and equivalent to the sum of the responses of thrips to plants damaged by single herbivore species feeding alone. For example, E occidentalis was attracted to T. urticae damaged plants but more attracted to undamaged plants than to plants damaged by H. armigera. Plants simultane- ously damaged by low densities of T. urticae and H. armigera repelled E occidentalis but as T. urticae density increased relative to H. armigera density, E occidentalis attraction to coinfested plants increased proportionally. Thrips tabaci did not discriminate between un- damaged plants and plants damaged by H. armigera but were attracted to plants damaged by T. urticae alone or simultaneously damaged by T. urticae and H. armigera. Olfactometer assays showed that simultaneous feeding by 2 herbivores on a plant can affect predator- prey interactions. Attraction of F. occidentalis to plants damaged by its T. urticae prey was reduced when the plant was simultaneously damaged by H. armigera, T. molitor, or A. gossypii and F. schultzei was more attracted to plants simultaneously damaged by T. urticae and H. armigera than to plants damaged by T. urticae alone. We conclude that plant responses to feeding by I species of herbivore are affected by responses to feeding by other herbivores. These plant-mediated interactions between herbivore complex展开更多
Flower thrips are one of the key pests in production of southern highbush blueberries (Vaccinium corymbosum L. × V. darrowi Camp). They feed on the reproductive parts of the flower and reduce yield. Very few inse...Flower thrips are one of the key pests in production of southern highbush blueberries (Vaccinium corymbosum L. × V. darrowi Camp). They feed on the reproductive parts of the flower and reduce yield. Very few insecticides are available to manage thrips population. Therefore, it is necessary to evaluate pre-existing and experimental insecticides for their efficacy against thrips. There is also a high demand for reduced-risk insecticides that are less toxic to beneficial insects and the environment. In this study, a number of conventional and reduced-risk insecticides were evaluated against flower thrips on farms in Florida and Georgia and in the laboratory. The best performing insecticides were also evaluated in the laboratory for their effects on Orius insidiosus Say, which is a common thrips’ predator in Florida. Assail 70WP (Acetamiprid) and SpinTor 2SC (Spinosad) were the most promising insecticides in reducing thrips numbers in the field as well as in laboratory experiments. SpinTor 2SC killed all of the thrips in laboratory arenas within 4 hours of application and showed low toxicity toward O. insidiosus. All of the compounds tested performed as well as the conventional pesticide malathion.展开更多
[Objective] The paper was to clear the species and occurrence regularity of thrips severely occurred in leek field, and to study the main control methods. [Methods] The species of thrips on leek were identified in Sic...[Objective] The paper was to clear the species and occurrence regularity of thrips severely occurred in leek field, and to study the main control methods. [Methods] The species of thrips on leek were identified in Sichuan Province, and the damage symptoms, occurrence regularity and control methods of thrips in leek field were studied. [Result] The morphological characteristic of thrips on leek was Frankliniella occidentalis(Pergande). ITS molecular identification results showed that the amplified fragment was 520 bp, which shared the similarity of 99.81% with the base se-quence of F. occidentalis. F. occidentalis concentrated at the height of 80 cm from the ground; in sunny days, the occurrence frequency of F. occidentalis was relatively high during 15:00 and 17:00; rainwater had obvious lethal effect on F. occidentalis, and the lethal rate was 29.30%. Field trial showed that 20% dinotefuran SG and 40% acetamiprid GR had good control effect against F. occidentalis. The control effect of 20% dinotefuran SG 1 500 times dilution was the best, up to 92.56%. [Conclusion] The results will provide effective technical support for large-scale control of thrips in leek field.展开更多
[Objective] The paper was to explore the effects of plant secondary metabolite on protective enzymes and detoxification enzymes of quarantine pest Frankliniella occidentalis. [Method] F. occidentalis were continuously...[Objective] The paper was to explore the effects of plant secondary metabolite on protective enzymes and detoxification enzymes of quarantine pest Frankliniella occidentalis. [Method] F. occidentalis were continuously exposed to artificial diets containing nicotine from the second to fifth instars for five generations, and the effects of nicotine on protective enzymes and detoxification enzymes of larvae were determined. [Result]The activities of carboxylate esterase(CarE) and glutathione-S-transferase(GST) in midgut of the fifth instar larvae were significantly increased, and reached the maximum at the third generation(1.86 times and 1.59 times, respectively). Nicotine inhibited the activities of superoxide dismutase(SOD) and catalase(CAT). With the increase of feeding generations, the inhibitory effect of nicotine weakened. Nicotine significantly increased the activities of peroxidase(POD). [Conclusion] F. occidentalis will gradually adapt to the harm of plant toxins by starting its own detoxification enzyme system and regulating protective enzyme system after feeding on plant secondary substance nicotine.展开更多
Tomato spotted wilt orthotospovirus(TSWV)causes substantial economic losses to vegetables and other crops.TSWV is mainly transmitted by thrips in a persistent and proliferative manner,and its most efficient vector is ...Tomato spotted wilt orthotospovirus(TSWV)causes substantial economic losses to vegetables and other crops.TSWV is mainly transmitted by thrips in a persistent and proliferative manner,and its most efficient vector is the western flower thrips,Frankliniella occidentalis(Pergande).In moving from the thrips midgut to the salivary glands in preparation for transmission,the virions must overcome multiple barriers.Although several proteins that interact with TSWV in thrips have been characterized,we hypothesized that additional thrips proteins interact with TSWV and facilitate its transmission.In the current study,67 F occidentalis proteins that interact with GN(a structural glycoprotein)were identified using a split-ubiquitin membrane-based yeast 2-hybrid(MbY2H)system.Three proteins,apolipoprotein-D(ApoD),orai-2-like(Orai),and obstructor-E-like isoform X2(Obst),were selected for further study based on their high abundance and interaction strength;their interactions with Gn were confirmed by MbY2H,yeastβ-galactosidase and luciferase complementation assays.The relative expressions of ApoD and Orai were significantly down-regulated but that of Obst was significantly up-regulated in viruliferous thrips.When interfering with Obst in larval stage,the TSWV acquisition rate in 3 independent experiments was significantly decreased by 26%,40%,and 35%,respectively.In addition,when Obst was silenced in adults,the virus titer was significantly decreased,and the TSWV transmission rate decreased from 66.7%to 31.9%using the leaf disk method and from 86.67%to 43.33%using the living plant method.However,the TSWV acquisition and transmission rates were not affected by interference with the ApoD or Orai gene.The results indicate that Obst may play an important role in TSWV acquisition and transmission in Frankliniella occidentalis.展开更多
The western flower thrips(WFT;Frankliniella occidentalis)is a mesophyll cell feeder that damages many crops.Management of WFT is complex due to factors such as high fecundity,short reproduction time,ability to feed on...The western flower thrips(WFT;Frankliniella occidentalis)is a mesophyll cell feeder that damages many crops.Management of WFT is complex due to factors such as high fecundity,short reproduction time,ability to feed on a broad range of host plants,and broad pesticide resistance.These challenges have driven research into developing alternative pest control approaches for WFT.This study analyzed the feasibility of a biological control-based strategy to manage WFT using RNA interference(RNAi)-mediated silencing of WFT endogenous genes.For the delivery of RNAi,we developed transgenic tomato lines expressing double-stranded RNA(dsRNA)of coatomer protein subunit epsilon(CopE)and Toll-like receptor 6(TLR6)from WFT.These genes are involved in critical biological processes of WFT,and their dsRNA can be lethal to these insects when ingested orally.Adult WFT that fed on the transgenic dsRNAexpressing tomato flower stalk showed increased mortality compared with insects that fed on wild-type samples.In addition,WFT that fed on TLR6 and CopE transgenic tomato RNAi lines showed reduced levels of endogenous CopE and TLR6 transcripts,suggesting that their mortality was likely due to RNAi-mediated silencing of these genes.Thus,our findings demonstrate that transgenic tomato plants expressing dsRNA of TLR6 and CopE can be lethal to F.occidentalis,suggesting that these genes may be deployed to control insecticide-resistant WFT.展开更多
Successful integrated pest management in protected crops implies an evalu-ation of the compatibility of pesticides and natural enemies(NE),as control strategies that only rely on one tactic can fail when pest populati...Successful integrated pest management in protected crops implies an evalu-ation of the compatibility of pesticides and natural enemies(NE),as control strategies that only rely on one tactic can fail when pest populations exceed NE activity or pests become resistant to pesticides.Nowadays in Almeria(Spain),growers release NE prior to transplanting or early in the crop cycle to favor their settlement before pest arrival because this improves biocontrol efficacy,although it extends pesticide exposure periods.The pur-pose of this research was to evaluate the compatibility of two applications of pesticides with key NE in 2-year trials inside tomato and sweet pepper commercial greenhouses:Nesidiocoris tenuis(Reuter)(Hemiptera:Miridae),Orius laevigatus(Say)(Hemiptera:Anthocoridae)and Amblyseius swirskii(Athias-Henriot)(Acari:Phytoseidac).In tomato,flubendiamide and chlorantraniliprole(IOBC category 1)were compatible with N.tenuis,but chlorpyrifos.:methyl and spinosad(IOBC categories 2-3),which efectively reduced Tiuta absoluta(Meyrick)(Lepidoptera:Gelechidae)density,compromised its predatory activity.In sweet pepper,chlorantraniliprole(IOBC category 1)was the only pesticide compatible with O.laevigatus while chlorantraniliprole,emamectin benzoate,spirote-tramat and pymetrozine were harmless(IOBC category 1)to Amblyseius swirskii,and sulfoxaflor slightly harmful(IOBC category 2)to this phytoseiid predator.展开更多
To survive in nature,organisms may need to take direct action to mitigate specific dangers from their environmental surroundings.Tiny flying insects are thought to be at particular risk from rainfall that would be of ...To survive in nature,organisms may need to take direct action to mitigate specific dangers from their environmental surroundings.Tiny flying insects are thought to be at particular risk from rainfall that would be of negligible concern to larger animals.The study species Frankliniella schultzei is a thrips that inhabits flowers and feeds mostly on petal tissue and pollen.While found to respond in the laboratory to decreases in atmospheric pressure associated with cyclonic conditions (rather than merely heavy rainfall),their responses to conditions preceding rainfall have not been tested in the field.Initial field sampling investigated the relationship between floral development and sites at which male,female,and larval thrips were generally present on sunny days.We then designed a sampling strategy to test if these thrips can anticipate imminent rainfall or storms and so seek shelter deep within flowers,by sampling host flowers (in sections)on multiple days with different weather conditions.Sticky traps were used to intercept thrips in flight,thus providing a measure of flight behavior across different days.The initial sampling found adult thrips primarily at the petal apex of anthesis-stage flowers where pollen is distributed. We subsequently found that rainfall,atmospheric pressure change,temperature,humidity and wind had no effect on flight behavior of E schultzei,or on their positions within flowers.These findings suggest rainfall is not a serious hazard for them.Perhaps thrips can survive raindrop collisions during flight,as impacts with water droplets are not expected to break the surface tension.展开更多
基金supported by the National Basic Research Program of China (973 Program, 2009CB119004)the National Special Fund for the Commonweal Agricultural Research of China (200903032)the Earmarked Fund for Modern Agro-industry Technology Research System, China (Nycytx-35-gw27)
文摘Thrips are among the most important agricultural pests globally because of the damage inflicted by their oviposition, feeding, and ability to transmit plant viruses. Because of their invasiveness, a number of pest species are common to both China and the United States and present significant challenges to growers of a wide range of crops in both countries. Among the pest thrips common to both countries are four of the major global thrips pests, Frankliniella occidentalis （Pergande）, Scirtothrips dorsalis Hood, Thrips palmi Karny, and Thrips tabaci Lindeman. This review addresses characteristics that enable thrips to be such damaging pests and how biological attributes of thrips create challenges for their management. Despite these challenges, a number of successful management tactics have been developed for various cropping systems. We discuss some of these tactics that have been developed, including the use of cultural controls, biological controls, and judicious use of insecticides that do not disrupt overall pest management programs. The exchange of this type of information will help to facilitate management of pest thrips, especially in regions where species have recently invaded. A prime example is F. occidentalis, the western flower thrips, which is native to the United States, but has recently invaded China. Therefore, management tactics developed in the United States can be adapted to China. Because further success in management of thrips requires a thorough understanding of thrips ecology, we discuss areas of future research and emphasize the importance of collaboration among different countries to enhance our overall understanding of the biology and ecology of thrips and to improve management programs for these widespread pests.
基金partially funded by the National Natural Science Foundation of China(31201526)the National 973 Program of China(2009CB119000)+1 种基金the Earmarked Fund for Modern AgroIndustry Technology Research System(CARS-25-B-07)the Special Fund for Agro-Scientific Research in the Public Interest of China(20090332)
文摘The westem flower thrips, Frankliniella occidental＆ （Pergande） is a highly invasive pest that is able to exploit many crops across a wide range of environmental conditions. Five full-length cDNAs of heat shock protein （HSP） genes （Fo-HSP90, Fo-HSP70, Fo-HSP60, Fo-HSP40 and Fo-HSP28.9） were cloned from F. occidentalis, and their expression profiles were investigated under conditions of thermal stress and insecticide exposure, and at different stages during development, using real-time quantitative PCR. All five gene sequences showed high similarity to homologs in other species, indicating the conserved fimction of this gene family. HSP60 represents an informative phylogenetic marker at the ordinal taxonomic level within Insecta, but HSP90, which has two homologous copies in Hymenoptera, was not informative. The expression of Fo-HSPs under thermal stress suggests that Fo-HSP90, Fo-HSP70, and Fo-HSP28.9 are inducible by both cold and heat stress, Fo-HSP40 is only heat-inducible, and Fo-HSP60 is thermally insensitive. There were two patterns of cold induction of Fo-HSPs： one is from 0 to 4℃ and the other is around -8℃. All five Fo-HSPs genes were induced by exposure to sublethal concentrations of the insecticide avermectin. The expression of the five Fo-HSPs during different developmental stages suggests that they all play a role in development of F. occidentalis.
基金financially supported by the National Natural Science Foundation of China (31371942)the National Key Research and Development Program,China (2016YFC1200600)the Ministry of Science and Technology,China
文摘The western flower thrips, Frankliniella occidentalis, is one of the most destructive sucking pests of vegetables, fruits and ornamental crops in China. Spinosad is one of the most commonly used insecticides to manage thrips. To assess the incidence of spinosad resistance in F. occidentalis field populations in eastern China, survival rates for 24 different populations were compared with those of a susceptible laboratory strain. All populations showed significantly higher resistance to spinosad compared with the control as determined by comparing median lethal concentrations. Two populations from Shouguang and Liaocheng in Shandong Province were classified as having moderate and high levels of resistance to spinosad with a mean resistance ratio of 17.0 and 89.2, respectively. Our research indicates a widespread reduction in spinosad efficacy for controlling F. occidentalis field populations, and that resistance management strategies should be implemented as soon as practicable, to reduce the potential of progressive resistance development and loss of efficacy.
文摘The daily flight activity of westem flower thrips, Frankliniella occidentalis （Pergande） （Thysanoptera： Thripidae） was examined using color, yellow-light and chemical attractant traps in a cucumber greenhouse and under controlled laboratory conditions. In the greenhouse, flying thrips were most abundant between hours 08：00-10：00, declined at mid-day, and then slightly increased during hours 14：00-16：00; however they decreased to a very low level at 18：00. The use of light traps showed no thrip flight activity during the night. The total number of thrips that flew onto cards on rainy or cloudy days was higher than that on sunny days. We reconfirmed that traps treated with attractant attracted 4.0-9.4 times more thrip than the untreated traps. Under laboratory controlled conditions, thrip flight activity was highest under light intensity between 4 000 and 6 000 lux, air temperature of 28℃, and RH of 70%. In addition, starved thrips flew more readily than non-starved thrips.
基金funded by the Special Fund for Agro-Scientific Research in the Public Interest of China (201103026, 200803025)the Science and Technology Innovation Project of Student in Yangzhou University,China (X20160637)
文摘Heat shock protein 70（HSP70） is one of the most important members in the heat shock protein family, and plays important roles in the thermotolerance of insect. To explore the molecular mechanism of thermotolerance of Frankliniella occidentalis adults, the difference in the expression of HSP70s in F. occidentalis male or female adults under the thermal stress was studied under the laboratory conditions. Two full length c DNAs of HSP70s gene（Fohsc704 and Fohsc705） were cloned from F. occidentalis by using RT-PCR and RACE. The genomic sequence was demonstrated by genomic validation, and the position and size of the intron were analyzed by sequence analysis of c DNA. Real-time PCR was used to analyze the HSP70 expression patterns. The c DNA of Fohsc704 and Fohsc705 possessed 2 073 and 1 476 bp which encoded 690 and 491 amino acids（aa） with a calculated molecular weight of 75 and 54 k Da, respectively. Four introns in Fohsc704 and six introns in Fohsc705 protein were found. However, the HSP70 protein sequences in our study were ended with EKKN and GIFL, which were different from the reported Fo HSP70s. Various expression patterns of Fohsc704 and Fohsc705 were found in both genders of F. occidentalis under thermal stress. The expression of Fohsc704 and Fohsc705 reached to the highest level at –12 and –8°C in male adults, respectively, and Fohsc705 expressed the highest level at 33°C in female adults. In conclusion, HSP70s of F. occidentalis in our study are novel heat shock proteins. There were difference in expression patterns of the two hsc70s in genders of F. occidentalis, and the two HSP70s play important roles in the thermotolerance of F. occidentalis.
基金Supported by National Natural Science Foundation of China(31301665)
文摘Impatiens necrotic spot virus( INSV) is an important plant virus identified in recent years. Western flower thrip( Frankliniella occidentalis) has been confirmed to be the most efficient vector for INSV. In the present study,Illumina's second-generation sequencing technique was used to determine the variation in gene expression at the transcriptome level in western flower thrip before and after infection with INSV. By aligning 168 188 unigenes of western flower thrip to the NCBI protein database,47 558 unigenes were annotated,accounting for 28. 27% of the total. Species classification revealed that 58. 7% of the annotated unigenes of western flower thrip did not match any other species,and 15. 4% of had a match in Zootermopsis navadensis,12. 4% in Mus musculus,7. 3% in Mustela putorius,3. 4% in Theileria parva,and 2. 7% in Tribolium castaneum. By analyzing DEGs between INSV-free and INSV-carrying western flower thrips,we found that 11 genes were upregulated,and 9 genes were downregulated in western flower thrip after INSV infection. In addition,cell cycle and ubiquitin-proteasome pathway in western flower thrip were significantly infected by INSV infection.
基金Supported by General Program of University Union of Yunnan Science and Technology Department(2017FH001-35)
文摘[Objective] The paper was to explore the chemical and molecular mechanisms of Frankliniella occidentalis, an important quarantine pest, against toxic substances. [Method] F. occidentalis were evaluated after continuous exposure to artificial diets containing nicotine from the 2^（nd） and the 3^（rd）instars for five generations, to determine the larval weight, pupal weight, and larval development duration. [Result] The larval development delayed and nicotine treatment significantly inhibited the weight gain of larvae. Compared to the control, the inhibition rates of larval weight and pupal weight were declined from 45% to 20% and from 25% to 4% respectively after feeding the 2^（nd）instars with nicotine for five generations.Nicotine delayed the larval growth and prolonged the generation duration of F. occidentalis. Nicotine showed more significant inhibitory effect on the lower instar larvae. With the increasing generations of secondary culture, the inhibitory effect of nicotine on larval weight and pupal weight was weakened. The developmental period of larvae was shortened, and the generation duration of F. occidentalis was shortened. [Conclusion] Nicotine affects the growth and development of F. occidentalis. F. occidentalis will gradually increase the adaptability to nicotine toxic substances after selfregulation for a few generations, and relieve the inhibitory effect of toxic substances.
文摘This study investigated the olfactory responses of 3 thrips species [Frankliniella schultzei Trybom, E occidentalis Pergrande and Thrips tabaci Lindeman （Thysanoptera： Thripidae）] to cotton seedlings [Gossypium hirsutum L. （Malvales： Malvaceae）] simulta- neously damaged by different combinations of herbivores. Cotton seedlings were damaged by foliar feeding Tetranychus urticae Koch （Trombidiforms： Tetranychidae）, Helicoverpa armigera Hibner （Lepidoptera： Noctuidae）, Aphis＇ gossypii Glover （Hemiptera： Aphidi- dae） or root feeding Tenebrio molitor L. （Coleoptera： Tenebrionidae）. Thrips responses to plants simultaneously damaged by 2 species of herbivore were additive and equivalent to the sum of the responses of thrips to plants damaged by single herbivore species feeding alone. For example, E occidentalis was attracted to T. urticae damaged plants but more attracted to undamaged plants than to plants damaged by H. armigera. Plants simultane- ously damaged by low densities of T. urticae and H. armigera repelled E occidentalis but as T. urticae density increased relative to H. armigera density, E occidentalis attraction to coinfested plants increased proportionally. Thrips tabaci did not discriminate between un- damaged plants and plants damaged by H. armigera but were attracted to plants damaged by T. urticae alone or simultaneously damaged by T. urticae and H. armigera. Olfactometer assays showed that simultaneous feeding by 2 herbivores on a plant can affect predator- prey interactions. Attraction of F. occidentalis to plants damaged by its T. urticae prey was reduced when the plant was simultaneously damaged by H. armigera, T. molitor, or A. gossypii and F. schultzei was more attracted to plants simultaneously damaged by T. urticae and H. armigera than to plants damaged by T. urticae alone. We conclude that plant responses to feeding by I species of herbivore are affected by responses to feeding by other herbivores. These plant-mediated interactions between herbivore complex
文摘Flower thrips are one of the key pests in production of southern highbush blueberries (Vaccinium corymbosum L. × V. darrowi Camp). They feed on the reproductive parts of the flower and reduce yield. Very few insecticides are available to manage thrips population. Therefore, it is necessary to evaluate pre-existing and experimental insecticides for their efficacy against thrips. There is also a high demand for reduced-risk insecticides that are less toxic to beneficial insects and the environment. In this study, a number of conventional and reduced-risk insecticides were evaluated against flower thrips on farms in Florida and Georgia and in the laboratory. The best performing insecticides were also evaluated in the laboratory for their effects on Orius insidiosus Say, which is a common thrips’ predator in Florida. Assail 70WP (Acetamiprid) and SpinTor 2SC (Spinosad) were the most promising insecticides in reducing thrips numbers in the field as well as in laboratory experiments. SpinTor 2SC killed all of the thrips in laboratory arenas within 4 hours of application and showed low toxicity toward O. insidiosus. All of the compounds tested performed as well as the conventional pesticide malathion.
基金Supported by Cooperation Project of Sichuan Academy of Agricultural Sciences and Pidu District "Integration and Demonstration of Green Prevention and Control Technology against Major Pests and Diseases in Leek"(2013YXHZPX-2)Pilot Demonstration Project of Sichuan Agricultural Scientific Achievements "Integration and Demonstration of High Yield and High Quality Production Technology of Leek"(2013ZSSH)Financial Innovation Enhancement Project of Sichuan Province "Integration and Demonstration of Green Prevention and Control Technology against Main Diseases and Pests of Vegetables"(2016GYSH-015)
文摘[Objective] The paper was to clear the species and occurrence regularity of thrips severely occurred in leek field, and to study the main control methods. [Methods] The species of thrips on leek were identified in Sichuan Province, and the damage symptoms, occurrence regularity and control methods of thrips in leek field were studied. [Result] The morphological characteristic of thrips on leek was Frankliniella occidentalis(Pergande). ITS molecular identification results showed that the amplified fragment was 520 bp, which shared the similarity of 99.81% with the base se-quence of F. occidentalis. F. occidentalis concentrated at the height of 80 cm from the ground; in sunny days, the occurrence frequency of F. occidentalis was relatively high during 15:00 and 17:00; rainwater had obvious lethal effect on F. occidentalis, and the lethal rate was 29.30%. Field trial showed that 20% dinotefuran SG and 40% acetamiprid GR had good control effect against F. occidentalis. The control effect of 20% dinotefuran SG 1 500 times dilution was the best, up to 92.56%. [Conclusion] The results will provide effective technical support for large-scale control of thrips in leek field.
基金Supported by University Joint General Program of Yunnan Department of Science and Technology(2017FH001-35)
文摘[Objective] The paper was to explore the effects of plant secondary metabolite on protective enzymes and detoxification enzymes of quarantine pest Frankliniella occidentalis. [Method] F. occidentalis were continuously exposed to artificial diets containing nicotine from the second to fifth instars for five generations, and the effects of nicotine on protective enzymes and detoxification enzymes of larvae were determined. [Result]The activities of carboxylate esterase(CarE) and glutathione-S-transferase(GST) in midgut of the fifth instar larvae were significantly increased, and reached the maximum at the third generation(1.86 times and 1.59 times, respectively). Nicotine inhibited the activities of superoxide dismutase(SOD) and catalase(CAT). With the increase of feeding generations, the inhibitory effect of nicotine weakened. Nicotine significantly increased the activities of peroxidase(POD). [Conclusion] F. occidentalis will gradually adapt to the harm of plant toxins by starting its own detoxification enzyme system and regulating protective enzyme system after feeding on plant secondary substance nicotine.
基金the China Agriculture Research System(CARS-24-C-02)the National Natural Science Foundation of China(32272548)+1 种基金the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-IVFCAAS)the Hainan Major Science and Technology Project(ZDKJ2021007)。
文摘Tomato spotted wilt orthotospovirus(TSWV)causes substantial economic losses to vegetables and other crops.TSWV is mainly transmitted by thrips in a persistent and proliferative manner,and its most efficient vector is the western flower thrips,Frankliniella occidentalis(Pergande).In moving from the thrips midgut to the salivary glands in preparation for transmission,the virions must overcome multiple barriers.Although several proteins that interact with TSWV in thrips have been characterized,we hypothesized that additional thrips proteins interact with TSWV and facilitate its transmission.In the current study,67 F occidentalis proteins that interact with GN(a structural glycoprotein)were identified using a split-ubiquitin membrane-based yeast 2-hybrid(MbY2H)system.Three proteins,apolipoprotein-D(ApoD),orai-2-like(Orai),and obstructor-E-like isoform X2(Obst),were selected for further study based on their high abundance and interaction strength;their interactions with Gn were confirmed by MbY2H,yeastβ-galactosidase and luciferase complementation assays.The relative expressions of ApoD and Orai were significantly down-regulated but that of Obst was significantly up-regulated in viruliferous thrips.When interfering with Obst in larval stage,the TSWV acquisition rate in 3 independent experiments was significantly decreased by 26%,40%,and 35%,respectively.In addition,when Obst was silenced in adults,the virus titer was significantly decreased,and the TSWV transmission rate decreased from 66.7%to 31.9%using the leaf disk method and from 86.67%to 43.33%using the living plant method.However,the TSWV acquisition and transmission rates were not affected by interference with the ApoD or Orai gene.The results indicate that Obst may play an important role in TSWV acquisition and transmission in Frankliniella occidentalis.
基金supported by the Basic Science Research Program through the National Research Foundation(NRF),Ministry of Education,Korea(2021R1I1A1A01041938)a grant from the New Breeding Technologies Development Program,Rural Development Administration,Korea(PJ0165432022)supported in part by the BK21 Plus Program,Ministry of Education,Korea。
文摘The western flower thrips(WFT;Frankliniella occidentalis)is a mesophyll cell feeder that damages many crops.Management of WFT is complex due to factors such as high fecundity,short reproduction time,ability to feed on a broad range of host plants,and broad pesticide resistance.These challenges have driven research into developing alternative pest control approaches for WFT.This study analyzed the feasibility of a biological control-based strategy to manage WFT using RNA interference(RNAi)-mediated silencing of WFT endogenous genes.For the delivery of RNAi,we developed transgenic tomato lines expressing double-stranded RNA(dsRNA)of coatomer protein subunit epsilon(CopE)and Toll-like receptor 6(TLR6)from WFT.These genes are involved in critical biological processes of WFT,and their dsRNA can be lethal to these insects when ingested orally.Adult WFT that fed on the transgenic dsRNAexpressing tomato flower stalk showed increased mortality compared with insects that fed on wild-type samples.In addition,WFT that fed on TLR6 and CopE transgenic tomato RNAi lines showed reduced levels of endogenous CopE and TLR6 transcripts,suggesting that their mortality was likely due to RNAi-mediated silencing of these genes.Thus,our findings demonstrate that transgenic tomato plants expressing dsRNA of TLR6 and CopE can be lethal to F.occidentalis,suggesting that these genes may be deployed to control insecticide-resistant WFT.
基金This research was funded by Spanish Ministry of Sci-ence,Innovation and Universities projects AGL2013-47603-C2-1-R and AGL2017-83498-C2-2-R awarded to Elisa Viuela and Pilar Medina,along with post-doctoral fellowships awarded to Beatriz Dader(Span-ish Ministry of Science,Innovation and Universities FJCI-2016-28443 and Universidad Politecnica de Madrid PINV18XFWLGK24S2US6D).We deeply appreciate the cooperation of two farmers that allowed us to perform tri-als in their commercial greenhouses.We are indebted to Dr.Christina Elizabeth Pease for English revision and to Dr.Ismael Sanchez from INIA for help with statistics.
文摘Successful integrated pest management in protected crops implies an evalu-ation of the compatibility of pesticides and natural enemies(NE),as control strategies that only rely on one tactic can fail when pest populations exceed NE activity or pests become resistant to pesticides.Nowadays in Almeria(Spain),growers release NE prior to transplanting or early in the crop cycle to favor their settlement before pest arrival because this improves biocontrol efficacy,although it extends pesticide exposure periods.The pur-pose of this research was to evaluate the compatibility of two applications of pesticides with key NE in 2-year trials inside tomato and sweet pepper commercial greenhouses:Nesidiocoris tenuis(Reuter)(Hemiptera:Miridae),Orius laevigatus(Say)(Hemiptera:Anthocoridae)and Amblyseius swirskii(Athias-Henriot)(Acari:Phytoseidac).In tomato,flubendiamide and chlorantraniliprole(IOBC category 1)were compatible with N.tenuis,but chlorpyrifos.:methyl and spinosad(IOBC categories 2-3),which efectively reduced Tiuta absoluta(Meyrick)(Lepidoptera:Gelechidae)density,compromised its predatory activity.In sweet pepper,chlorantraniliprole(IOBC category 1)was the only pesticide compatible with O.laevigatus while chlorantraniliprole,emamectin benzoate,spirote-tramat and pymetrozine were harmless(IOBC category 1)to Amblyseius swirskii,and sulfoxaflor slightly harmful(IOBC category 2)to this phytoseiid predator.
文摘To survive in nature,organisms may need to take direct action to mitigate specific dangers from their environmental surroundings.Tiny flying insects are thought to be at particular risk from rainfall that would be of negligible concern to larger animals.The study species Frankliniella schultzei is a thrips that inhabits flowers and feeds mostly on petal tissue and pollen.While found to respond in the laboratory to decreases in atmospheric pressure associated with cyclonic conditions (rather than merely heavy rainfall),their responses to conditions preceding rainfall have not been tested in the field.Initial field sampling investigated the relationship between floral development and sites at which male,female,and larval thrips were generally present on sunny days.We then designed a sampling strategy to test if these thrips can anticipate imminent rainfall or storms and so seek shelter deep within flowers,by sampling host flowers (in sections)on multiple days with different weather conditions.Sticky traps were used to intercept thrips in flight,thus providing a measure of flight behavior across different days.The initial sampling found adult thrips primarily at the petal apex of anthesis-stage flowers where pollen is distributed. We subsequently found that rainfall,atmospheric pressure change,temperature,humidity and wind had no effect on flight behavior of E schultzei,or on their positions within flowers.These findings suggest rainfall is not a serious hazard for them.Perhaps thrips can survive raindrop collisions during flight,as impacts with water droplets are not expected to break the surface tension.
