Western flower thrips resistance to insecticides: detection, mechanisms and management strategies

Insecticide resistance continues to be one of the most important issues facing agricultural production. The challenges in insecticide resistance and its management are exemplified by the situation with the western flower thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). This highly invasive pest has a great propensity for developing insecticide resistance because of its biological attributes, and cases of resistance to most classes of insecticides used for its management have been detected. To combat insecticide resistance in the western flower thrips, several insecticide resistance management (IRM) programs have been developed around the world, and these are discussed. Successful programs rely on non-insecticidal tactics, such as biological and cultural controls and host plant resistance, to reduce population pressures, rotations among insecticides of different mode of action classes to conserve insecticide efficacy, resistance monitoring, sampling to determine the need for insecticide applications and education to assure proper implementation. More judicious insecticide use is possible with the development of well-founded economic thresholds for more cropping systems. While growers will continue to rely on insecticides as part of western-flower-thrips- and thrips-transmitted virus management, more effective management of these pests will be achieved by considering their management in the context of overall integrated pest management, with IRM being a key component of those comprehensive programs.     

西花蓟马抗药性研究进展

西花蓟马是世界范围内蔬菜和花卉上的重要害虫之一,使用化学药剂是防治西花蓟马的主要手段,目前西花蓟马已对有机氯、有机磷、氨基甲酸酯、拟除虫菊酯、阿维菌素和多杀菌素等多种杀虫剂产生了抗药性。本文从抗药性现状、抗性机制和抗性治理等几个方面介绍了国内外有关西花蓟马抗药性的研究进展。     

Tree fruit IPM programs in the western United States: the challenge of enhancing biological control through intensive management

The seminal work of Stern and his coauthors on integrated control has had a profound and long‐lasting effect on the development of IPM programs in western orchard systems. Management systems based solely on pesticides have proven to be unstable, and the success of IPM systems in western orchards has been driven by conservation of natural enemies to control secondary pests, combined with pesticides and mating disruption to suppress the key lepidopteran pests. However, the legislatively mandated changes in pesticide use patterns prompted by the Food Quality Protection Act of 1996 have resulted in an increased instability of pest populations in orchards because of natural enemy destruction. The management system changes have made it necessary to focus efforts on enhancing biological control not only of secondary pests but also of primary lepidopteran pests to help augment new pesticides and mating disruption tactics. The new management programs envisioned will be information extensive as well as time sensitive and will require redesign of educational and outreach programs to be successful. The developing programs will continue to use the core principles of Stern and his co‐authors, but go beyond them to incorporate changes in society, technology and information transfer, as needed. Copyright © 2009 Society of Chemical Industry     

Insecticide Resistance in the Western Flower Thrips, Frankliniella occidentalis

The western flower thrips, Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) is a serious pest on a wide range of crops throughout the world. F. occidentalis is difficult to control with insecticides because of its thigmokinetic behaviour and resistance to insecticides. Pesticide resistance can have a negative impact on integrated pest management programmes with chemical control as one of the components. Resistance to a number of different insecticides has been shown in many populations of F. occidentalis. This flower thrips has the potential of fast development of resistance owing to the short generation time, high fecundity, and a haplodiploid breeding system. The mechanisms conferring insecticide resistance in insects can be divided into four levels. First, an altered behaviour can aid the insect to avoid coming into contact with the insecticide. Second, a delayed penetration through the integument will reduce the effect of the insecticide at the target site. Third, inside the insect, detoxification enzymes may metabolise and thereby inactivate the insecticide. Fourth, the last level of resistance mechanisms is alterations at the target site for the insecticide. Knowledge of resistance mechanisms can give information and tools to be used in management of the resistance problem. Recently, studies have been carried out to investigate the underlying mechanisms conferring resistance in F. occidentalis. It appears that resistance in F. occidentalis is polyfactorial; different mechanisms can confer resistance in different populations and different mechanisms may coexist in the same population. Possible resistance mechanisms in F. occidentalis include: reduced penetration, detoxification by P450-monooxygenases, esterases and glutathione S-transferases, and alterations of acetylcholinesterase, the target site for organophosphate and carbamate insecticides. Target site resistance to pyrethroids (knockdown resistance) may also be a resistance mechanism in F. occidentalis.     

Integrated pest management in western flower thrips: past,present and future

Western flower thrips (WFT) is one of the most economically important pest insects of many crops worldwide. Recent EU legislation has caused a dramatic shift in pest management strategies, pushing for tactics that are less reliable on chemicals. The development of alternative strategies is therefore an issue of increasing urgency. This paper reviews the main control tactics in integrated pest management (IPM) of WFT, with the focus on biological control and host plant resistance as areas of major progress. Knowledge gaps are identified and innovative approaches emphasised, highlighting the advances in ‘omics’ technologies. Successful programmes are most likely generated when preventive and therapeutic strategies with mutually beneficial, cost‐effective and environmentally sound foundations are incorporated. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

基于生物防治的西花蓟马治理及思考

西花蓟马Frankliniella occidentalis(Pergande)是世界性的大害虫,对温室中蔬菜花卉造成巨大的危害。20世纪70年代后在世界范围内广泛而迅速地传播蔓延,近年入侵中国。西花蓟马对农药产生了广泛的抗性,使得生物防治一直作为其综合治理中的主导措施。本文综述了世界上西花蓟马生物防治的现状,以期为中国西花蓟马的治理提供一定的借鉴作用。     

Evaluation of metabolic detoxifying enzyme activities and insecticide resistance in Frankliniella occidentalis

The western flower thrips Frankliniella occidentalis (Pergande) is a very significant pest of a number of different agricultural crops in the south-east of Spain. The importance of thrips as a pest is not due mainly to the direct damage inflicted on the plant, but to the loss in commercial value which occurs as a consequence of the development of dark spots caused by the tomato spotted wilt virus (TSWV) which they transmit. The economic threshold is therefore almost zero, which enhances the problems of resistance management. The present work is part of a global project that attempts to evaluate the status of insecticide resistance in field populations of thrips obtained from several agricultural crops. We have studied, in either individual or pooled insects, some enzyme systems classically related to detoxification of insecticides: esterase and glutathione-S-transferase (GST). The activity of these enzymes from laboratory populations selected with various classes of insecticides has also been measured using several appropriate substrates. An increase in GST mean activity was found in two field-collected strains. Differences in frequency distributions of esterase and GST activities were found for both field-collected strains and for a laboratory strain selected with acrinathrin. These activities were compared with those of a wild-type reference strain.     

Verbena as a trap crop to suppress thrips-transmitted Tomato spotted wilt virus in chrysanthemums

The effect of verbena as a trap crop on the occurrence of western flower thrips, Frankliniella occidentalis, and the incidence of Tomato spotted wilt virus (TSWV) in chrysanthemums were investigated. Verbena cvs. Pink Parfait and/or Fancy Parfait were cultivated alongside chrysanthemum cv. Jimba in a greenhouse in the proportion of 17%–25% of the chrysanthemum plants. Verbena plants attracted vector thrips, reducing western flower thrips colonization of chrysanthemum until flower bud initiation, and markedly suppressing TSWV incidence on chrysanthemums until flowering. Significant quantities of linalool oxide pyran were produced by the flower of cv. Fancy Parfait; and the ratio of cis-linalool oxide pyran, an attractant for vector thrips, to the trans-type was approximately 1 : 5. Our results suggest that cultivation of verbena as a trap crop may be useful in integrated pest management programs as a control for thrips-transmitted TSWV in chrysanthemums.     

甘蔗害虫综合防治研究

1981—1984年广东省开展甘蔗害虫综合防治研究、试验、示范。采取“以农业防治为基础,释放赤眼蜂防治蔗螟;科学用药,保护天敌,充分发挥天敌自然控制多种害虫的作用”。在10万亩大面积上,收到到了显著的经济效益、生态效益和环境保护效益。     

Relationship between esterase activity and acrinathrin and methiocarb resistance in field populations of western flower thrips, Frankliniella occidentalis

The western flower thrips, Frankliniella occidentalis (Pergande), is a serious pest in the south-east of Spain owing to its direct feeding on crops, transmission of the tomato spotted wilt virus and its very high level of resistance to insecticides. Mechanisms of resistance were examined using field populations of F. occidentalis with different susceptibilities to acrinathrin, methiocarb (selective insecticides), endosulfan, metamidophos and deltamethrin (broad-spectrum insecticides). Esterase activity towards alpha-naphthyl acetate and p-nitrophenyl acetate in resistant strains was significantly higher than in the reference strain (MLFOM) for both model substrates. This higher activity was significantly correlated with acrinathrin and methiocarb resistance.     

The efficacy of spinosad against the western flower thrips, Frankliniella occidentalis, and its impact on associated biological control agents on greenhouse cucumbers in southern Ontario

Insecticides are the most commonly used tactic to control western flower thrips (WFT), Frankliniella occidentalis Pergande (Thysanoptera: Thripidae), on greenhouse cucumber. However, WFT has developed resistance to several of the insecticides presently in use. In addition, some of these insecticides adversely affect greenhouse biological control agents used to control WFT, resulting in subsequent pest resurgence. Therefore, there is a need to identify novel insecticides with unique modes of action for use in integrated pest management (IPM) programs to effectively control WFT with minimal impact on associated biological control agents. In laboratory bioassays conducted in 2001, immature and adult WFT and three associated greenhouse biological control agents: Amblyseius cucumeris Oudemans (Acarina: Phytoseiidae), Orius insidiosus Say (Hemiptera: Anthocoridae) and Encarsia formosa Gahan (Hymenoptera: Aphelinidae) were exposed to direct, direct/residual, and residual contact applications of the novel biopesticide, spinosad (Conserve 120 SC), and the industry standard for whitefly control, endosulfan (Thiodan 50 WP). In all three types of assay, spinosad was effective against immature and adult WFT life stages. It showed low toxicity to A. cucumeris, moderate toxicity to O. insidiosus and high toxicity to E formosa. Greenhouse studies involving exposure of immature and adult WFT and adult biological control agents to cucumber leaves sprayed previously with spinosad supported the laboratory data. Spinosad showed low toxicity to A. cucumeris exposed to leaves 1 day after treatment (DAT), moderate toxicity to O. insidiosus 1 and 8 DAT, and high toxicity to E. formosa up to 28 DAT. These data, along with spinosad's unique mode of action, suggest it would be a valuable reduced-risk control agent for greenhouse cucumber IPM programs.     

Insecticide resistance management strategies against the western flower thrips, Frankliniella occidentalis

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.     

Integrated management of Thrips tabaci (Thysanoptera: Thripidae) on onion in north‐western Italy: basic approaches for supervised control

BACKGROUND: Thrips tabaci Lindeman (Thysanoptera: Thripidae) is a major pest on onion, Allium cepa L., worldwide. In 2010, research was conducted in a commercial onion field in north‐western Italy in order (i) to evaluate the efficacy of different insecticides and of the SAR activator acibenzolar‐S‐methyl, (ii) to correlate thrips infestation levels with bulb size and weight at harvest and (iii) to implement a reliable thrips sampling method. Efficacy of the three active ingredients spinosad, lambda‐cyhalothrin and acibenzolar‐S‐methyl on local thrips populations were also evaluated in laboratory bioassays. RESULTS: During field surveys, the highest and the lowest thrips infestations were observed in plots treated with lambda‐cyhalothrin and with spinosad and acibenzolar‐S‐methyl respectively. The effectiveness of spinosad was also confirmed in laboratory bioassays. At harvest, bulb size and weight did not significantly differ between treatments. A high correlation with visual inspection made plant beating a suitable sampling method for routine practice, enabling a good estimate of thrips infestation. CONCLUSION: Damage caused by thrips is often not severe enough to warrant the frequent pesticide applications the crops receive in north‐western Italy. The use of spinosad and acibenzolar‐S‐methyl is suggested as an alternative to conventional insecticides for the preservation of natural enemies. Copyright © 2011 Society of Chemical Industry     

Evaluation of medium treatments for management of Frankliniella occidentalis (Thripidae: Thysanoptera) and Bradysia coprophila (Diptera: Sciaridae)

Two greenhouse experiments, each comprising two trials, were conducted to evaluate medium drenches of insect growth regulators and conventional insecticides to reduce emergence of adult western flower thrips, Frankliniella occidentalis (Pergande), and fungus gnats, Bradysia coprophila (Lintner) from the medium. In the insect growth regulator trials, diflubenzuron and pyriproxyfen provided the greatest reduction in thrips emergence, and fenoxycarb, pyriproxyfen and azadirachtin resulted in the most significant reduction of fungus gnat emergence. Treatments with the contact insecticides, methiocarb and chlorpyrifos, resulted in the greatest reduction of thrips and fungus gnat populations. These data suggest that fungus gnats are susceptible to many compounds used in commercial greenhouse production. Even though medium drenches are not currently used for thrips management, drenches with diflubenzuron, pyriproxyfen, methiocarb and chlorpyrifos could aid in reducing thrips populations in greenhouse management programs. © 2001 Society of Chemical Industry     

Resistance and cross-resistance to the spinosyns - A review and analysis

The spinosyns were introduced in 1997 with the launch of spinosad. Since then, there have been several cases of resistance to spinosad in the field populations of insect pest species that have resulted in reduced efficacy. There have also been a number of studies where spinosad-resistant insect strains were created and characterized in the laboratory. Likewise many studies examining resistance to a variety of other classes of insecticides have included spinosad in the evaluation of their cross-resistance spectrum. Understanding mechanisms of resistance and cross-resistance can provide the basis for developing insecticide resistance management programs, as well as defining the most appropriate tools to address potential resistance issues. This review provides an overview and analysis of resistance and cross-resistance to the spinosyns (spinosad and spinetoram). Although there are more than 30 examples of resistance to the spinosyns, only half of these are related to selection in the field. The majority of these field selected examples occur in either the diamondback moth or western flower thrips. There have also been over 85 studies investigating cross-resistance to the spinosyns. However, in half of these studies spinosad showed no cross-resistance, and in another third of the total studies spinosad cross-resistance was minimal. Therefore, while resistance and cross-resistance to the spinosyns does occur, it is appears to be more limited in impact than might be implied from the large body of literature on the subject.     

郭予元院士在棉铃虫区域性综合防治技术体系研究及应用中的学术贡献——纪念郭予元院士诞辰90周年

郭予元院士带领团队研究人员通过多年协同攻关研究，解析了棉铃虫发生为害规律和自然种群生命表机制，明确了棉铃虫对多种农药抗药性动态并应用于棉田抗药性治理，揭示了黄河流域棉区棉花对不同世代棉铃虫为害的补偿生长规律和防治策略，基于不同世代棉铃虫为害阈值和防治指标创建了准确预报二代棉铃虫发生数量的一代麦田扫网法，开展棉花种质资源抗病虫性鉴定并指导选育多抗棉花系列新品种。通过整合诱杀、选择性杀虫剂、生物农药与化学农药次序使用和局部精准施药等绿色防治技术，组建区域性棉花主要病虫害综合防治技术体系，棉区棉铃虫为害得到有效控制，引领了我国农作物主要病虫害综合防治技术的发展。本文简要回顾了郭予元院士在该领域研究中做出的主要历史贡献。     

M?glichkeiten der Bek?mpfung des Kalifornischen Bl��tenthripses Frankliniella occidentalis (Pergande) mit nachgewiesener Insektizidresistenz in Schnittrosen unter Glas

Due to resistance to insecticides (or plant protecting agents) the western flower thrips Frankliniella occidentalis is difficult to combat in cut roses cultures with conventional methods. In that case the predatory mite Amblyseius cucumeris could be a very effective biological alternative when applied in high numbers of 1000 mites per square meter against low density thrips population. The key to success is early application at the beginning of the vegetative growth before the thirps becomes active and the first larvae appear. The efficiency of the mites is not sufficient when the thirps population density in spring is high. Caused by the fecundity and fast development of Frankliniella occidentalis in higher temperatures, the application of chemical protecting agents in summer could be unavoidable. Because of the proven resistance Western flower thrips developed against the insecticides permitted in Germany, the chemical agents may not be effective. Only an optimal application can provide a satisfactory reduction of the thrips population. The development stage of the roses must be taken into account as well as right application intervals of insecticides. In order to develop a sufficient and effective control of Western flower thrips Frankliniella occidentalis and improve resistance management the application of predatory mites seems to be inevitable in future.     

The effects of intercropping with cereals and minimal permethrin applications on insect pests of cowpea and their natural enemies in Nigeria

Abstract

Major insect pests and their natural enemies were sampled on cowpea in monocrop and cereal intercrop plots in southern and northern Nigeria. Populations of flower thrips, Megalurothrips sjostedti (Trybom), were reduced by 42% and predators, mostly Orius spp. (Anthocoridae), by 23% on cowpea in maize intercrop plots at Ofiki in the south. Infestation by pyralid pod borer, Maruca testulalis Geyer, was unaffected by cropping system. The results suggest that tasselling maize attracts flower‐eating beetles (Meloidae) to intercrop plots, and that pod‐sucking Hemiptera were increased by cereal intercrops at Yankara in the north. Three u.l.v. applications of permethrin at 150 g a.i./ha to monocrop cowpea reduced pest populations by 50 to 85% in the south and increased yield sevenfold. However, the sprayed crop in the north was lost due to a heavy infestation of pod‐sucking bug, Clavigralla tomentosicollis Stål, and outbreaks of Aphis craccivora Koch on sprayed plots in both localities suggested damage to natural enemies. It is concluded that the pest management potential of intercropping is variable and dependent on environmental factors, but it is recommended that intercropping be used in integrated pest management systems with the progressive decrease in insecticide use.     

Integrated pest management in groundnut (Arachis hypogaea L.) in India

A large number of pests are associated with groundnut but not all are economically important. The distribution of, losses and damage caused by groundnut pests are discussed, along with a variety of control measures and methods for their integration for effective pest management. Disease resistant/tolerant varieties, including Girnar 1, ALR 1, ICGV 87160, ICGV 86590, DH 8, TG 3, MH 16, ICGS 37 and TAG 24 from India have been released for general cultivation and could be used in integrated pest management (IPM) programmes. A large number of advanced breeding lines possessing resistance to major diseases and insect pests have been identified. Biocontrol agents have been used successfully for insect and disease control. Intercrops such as pearlmillet and soybean suppress thrips, jassids and leaf miner; castor suppresses jassids and Spodoptera, and pigeonpea suppress early leaf spot, late leaf spot and rust. These plants act as traps or barriers for reducing pest incidence. The use of pheromone traps for gram pod borers, tobacco caterpillars and leaf miners, and the use of neem products against major insect pests and diseases, are novel approaches that may reduce the cost of groundnut production. If pest control measures are integrated in an optimum proportion and pest surveillance activity is strengthened further, maximum returns could be realized     

High‐level of resistance to spinosad,emamectin benzoate and carbosulfan in populations of Thrips tabaci collected in Israel

BACKGROUND: The onion thrips, Thrips tabaci Lindeman, is a major pest of several crop plants in the genus Allium, such as onions, garlic and chives. In Israel, these crops are grown in open fields and in protected housing. This thrips is usually controlled by the application of chemical insecticides. In recent years, spinosad, emamectin benzoate and carbosulfan have been the major insecticides used for the control of the onion thrips. In the last 4 years, growers of chives and green onion from several regions of Israel have reported a significant decrease in the efficacy of insecticides used to control the onion thrips. RESULTS: The susceptibility of 14 populations of the onion thrips, collected mainly from chives between the years 2007 and 2011, to spinosad, emamectin benzoate and carbosulfan was tested using a laboratory bioassay. The majority of the populations showed significant levels of resistance to at least one of the insecticides. LC₅₀ values calculated for two of the studied populations showed that the resistance factor for spinosad compared with the susceptible population is 21 393, for carbosulfan 54 and for emamectin benzoate 36. Only two populations, collected from organic farms, were susceptible to the insecticides tested. CONCLUSION: This is the first report of a high resistance level to spinosad, the major insecticide used to control the onion thrips. Resistance cases to spinosad were associated with failures to control the pest. Populations resistant to spinosad also had partial or complete resistance to other insecticides used for controlling the onion thrips. Copyright © 2012 Society of Chemical Industry