Q型烟粉虱对20个烟草品种的选择性

为了明确不同烟草品种对Q型烟粉虱的抗性及其与叶背茸毛密度的相关性,研究了Q型烟粉虱对20个烟草品种的选择性及其生长发育和存活情况,并分析了烟草抗虫性与叶背茸毛密度的关系。结果表明,Q型烟粉虱成虫对烟草品种的选择性、产卵趋性及卵-成虫的存活率在不同烟草品种间差异显著。在20个供试烟草品种中,抗虫性较弱的品种有‘闽烟9号’、‘闽烟57号’;抗虫性较强的品种有‘云烟97’、‘V2’、‘云烟100’、‘长脖黄’,这4个品种在生产上可优先安排种植。烟草叶背茸毛密度与成虫量和着卵量均呈极显著正相关,即烟草叶背茸毛密度越高,烟草抗虫性越弱。因此,选育茸毛较少的烟草品种,可以提高烟草对Q型烟粉虱的抗性。     

Biotype and insecticide resistance status of the whitefly Bemisia tabaci from China

BACKGROUND: Resistance to numerous insecticide classes in Bemisia tabaci Gennadius has impaired field control efficacy in south‐eastern China. The biotype and resistance status of B. tabaci collected from these areas was investigated. RESULTS: Two different biotypes of B. tabaci (B‐biotype and Q‐biotype) were detected in south‐eastern China, and the samples collected from geographical regions showed a prevalence of the Q‐biotype and the coexistence of B‐ and Q‐biotypes in some regions. Moderate to high levels of resistance to two neonicotinoids were established in both biotypes (28–1900‐fold to imidacloprid, 29–1200‐fold to thiamethoxam). Medium to high levels of resistance to alpha‐cypermethrin (22–610‐fold) were also detected in both biotypes. Four out of 12 populations had low to medium levels of resistance to fipronil (10–25‐fold). Four out of 12 populations showed low levels of resistance to spinosad (5.7–6.4‐fold). All populations tested were susceptible to abamectin. CONCLUSION: The Q‐biotype B. tabaci is supplanting the B‐biotype which used to be ubiquitous in China. Field populations of both B‐ and Q‐biotypes of B. tabaci have developed high levels of resistance to imidacloprid and thiamethoxam. Abamectin is the most effective insecticide against adult B. tabaci from all populations. Copyright © 2010 Society of Chemical Industry     

Biochemical study of resistance to imidacloprid in B biotype Bemisia tabaci from Guatemala

Systemic uptake bioassays using excised cotton leaves confirmed resistance to imidacloprid in a Guatemalan population of the tobacco whitefly Bemisia tabaci Gennadius. Polyacrylamide gel electrophoresis of naphthyl esterases identified the insects as B-types. Upon collection from the field, resistance was determined to be 58-fold relative to a susceptible strain originating in the Imperial Valley of California. Resistance levels increased to 126-fold in this population during its continuous exposure to systemically treated cotton. In biochemical investigations, there was no detectable NADPH-dependent mixed function oxidase metabolism of 14C-imidacloprid at any time during the selection process. In contrast, microsomal preparations from housefly abdomens readily produced significant amounts of the mono-hydroxy and olefin derivatives of the parent compound. Detoxification of imidacloprid by housefly MFOs may account for reports of lower toxicity of the insecticide towards this insect compared with whiteflies, despite similar binding properties between imidacloprid and the nicotinic acetylcholine receptors in both species.     

在北京和河北局部地区Q型烟粉虱取代了B型烟粉虱

利用烟粉虱[Bemisia tabaci(Gennadius)]B生物型和Q生物型mtDNA COⅠ基因片段的特异性引物及烟粉虱mtDNA COⅠ基因片段通用引物,对2009年采自北京市海淀区、昌平区和河北廊坊市的蔬菜所3个基地的烟粉虱种群的生物型进行了鉴定,同时以本实验室在温室内长期饲养的B型烟粉虱种群作为对照。结果表明,2009年在3个地区所采集的烟粉虱全部为Q型,而在2004年这3个基地发生为害的烟粉虱全部为B型,表明Q型烟粉虱已经取代了B型烟粉虱在这些地区发生为害。     

宁夏地区烟粉虱对5种常用杀虫剂的抗药性

采用浸叶法分别测定了宁夏8个地区烟粉虱成虫田间种群对4类5种杀虫剂的抗性.结果 表明,供试烟粉虱种群对高效氯氰菊酯已产生了中等至极高水平抗性,抗性倍数为33.31～227.98倍;对烯啶虫胺产生了中等至高水平抗性,抗性倍数为12.14～69.33倍;对毒死蜱和吡虫啉产生了低至中等水平抗性,抗性倍数分别为7.63～38....     

湖北省棉花主产区烟粉虱生物型分布及系统发育分析

［目的］ 明确武汉、荆州、孝感、随州、武穴5个棉花主产区烟粉虱生物型组成。［方法］ 通过以线粒体细胞色素氧化酶I（mitochondrial cytochrome oxidase I, mtCOI）为基础的PCR RFLP和基因测序的方法,鉴定湖北5个棉花主产区烟粉虱地理种群的生物型组成,并分析5个地理种群与其他省种群的系统发育关系。［结果］ Q型烟粉虱为湖北省棉花主产区的优势种群,而武汉温室种群则均为B型烟粉虱,土著生物型ZHJ1型在大田中略有分布;系统发育分析表明,湖北省棉花主产区B型和Q型烟粉虱种群均与中国其他多个省的烟粉虱种群亲缘关系较近。［结论］ 本文研究结果可以为湖北省5个棉花主产区烟粉虱的有效防治提供参考。     

6种杀虫剂对Q型烟粉虱的田间防治效果及抗性测定

本文测试了6种常用杀虫剂对黄瓜上Q型烟粉虱的田间防治效果,并进行室内毒力测定,以确定Q型烟粉虱对不同药剂的抗性。结果表明,施药后第3天,阿维菌素防治效果达78.8%,其次为苦参&;#8226;内酯,防效达65.1%,其他药剂防效低于45%;施药7d后,6种供试杀虫剂防效均下降到45%以下,且药剂间的差异不显著。毒力测定显示,Q型烟粉虱对6种常用杀虫剂均产生不同程度的抗性,且抗性水平高于B型。其中,Q型对高效氯氰菊酯抗性（抗性倍数47.69）显著高于B型（抗性倍数7.19）;对阿维菌素抗性则相对较低,抗性指数仅为4.40;对苦参碱、啶虫脒和吡虫啉的抗性居中（抗性倍数4.57~9.44）。     

烟粉虱抗、感杀虫剂品系内生菌群落的差异分析

本研究对B型和Q型烟粉虱的吡虫啉或吡丙醚的抗、感品系进行16SrRNA细菌多样性测序分析,以明确内共生菌的种类和数量与烟粉虱生物型和抗性的关系。结果表明Candidatus Nitrososphaera、Bacillus、Sphingobium只在Q型烟粉虱中存在,而Candidatus Hamiltonella、Lactobacillus、Helicobacter等只在B型烟粉虱中存在,说明这些内共生菌可能与烟粉虱B、Q两种生物型的分化有关;内共生菌Rickettsia、Candidatus Portiera、Candidatus Hamiltonella、S24-7、Prevotella等在烟粉虱的新烟碱类杀虫剂吡虫啉抗性品系中明显多于敏感品系,其可能与烟粉虱对吡虫啉的抗性有关;在对保幼激素类似物杀虫剂吡丙醚的抗性品系中,Candidatus Hamiltonella-OTU7、Candidatus Portiera-OTU5、Candidatus Portiera-OTU190、Rickettsia-OTU4、Rickettsia-OTU2的数量明显多于敏感品系,说明这些内共生菌可能与烟粉虱对该类药物的抗性有关。     

棉田间作蔬菜防治B型烟粉虱

在室内用"Y"形嗅觉仪以棉花为对照测定了B型烟粉虱对6种蔬菜的选择性,不同蔬菜对B型烟粉虱诱集率的大小为:菜豆花生茴香芫荽芹菜韭菜。除了烟粉虱对菜豆的选择系数为正值外,烟粉虱对其他几种蔬菜的选择系数均为负值。6种蔬菜与棉花间作,结果表明:间作棉花上的烟粉虱成虫数量与对照存在显著差异。除了间作菜豆棉花上的烟粉虱成虫数量比对照增加外,间作花生、茴香、芫荽、芹菜、韭菜的棉花上烟粉虱成虫数量比对照均减少。     

Toxicity of spiromesifen to the developmental stages of Bemisia tabaci biotype B

BACKGROUND: Spiromesifen is a novel insecticidal/acaricidal compound derived from spirocyclic tetronic acids that acts effectively against whiteflies and mites via inhibition of acetyl‐CoA‐carboxylase, a lipid metabolism enzyme. The effects of spiromesifen on the developmental stages of the whitefly Bemisia tabaci (Gennadius) were studied under laboratory conditions to generate baseline action thresholds for field evaluations of the compound. RESULTS: Adult B. tabaci mortality rate after spiromesifen treatment (5 mg L^?1) was 40%. Treatment with 0.5 mg L^?1 reduced fecundity per female by more than 80%, and fertility was almost nil. LC₅₀ for eggs was 2.6 mg L^?1, and for first instar 0.5 mg L^?1. Scanning electron microscopy revealed that eggs laid by treated adult females had an abnormally perforated chorion, and females were unable to complete oviposition. Light and fluorescent microscopy showed significantly smaller eggs following treatment, and smaller, abnormally formed and improperly localized bacteriomes in eggs and nymphs. The number of ovarioles counted in females treated with 5 mg L^?1 was significantly reduced. Spiromesifen showed no cross‐resistance with other commonly used insecticides from different chemical groups, and resistance monitoring in Israel showed no development of field resistance to this insecticide after 1 year of use. CONCLUSION: The strong effect on juvenile stages of B. tabaci with a unique mode of action and the absence of cross‐resistance with major commonly used insecticides from different chemical groups suggest the use of spiromesifen in pest and resistance management programmes. Copyright © 2008 Society of Chemical Industry     

Lack of fitness costs associated with pyriproxyfen resistance in the B biotype of Bemisia tabaci

BACKGROUND: The insect growth regulator pyriproxyfen has provided effective control of the whitefly Bemisia tabaci Gennadius in many countries. Here, whether or not fitness costs were associated with pyriproxyfen resistance in a laboratory‐selected resistant strain (QC02‐R) of the B biotype was determined. RESULTS: Mortality caused by pyriproxyfen and fitness traits over time were measured in unselected and selected hybrid strains, which were created by crossing individuals of the resistant strain with individuals of a susceptible strain. Fitness costs were not associated with resistance in QC02‐R, as mortality caused by pyriproxyfen did not increase over time in unselected hybrid strains and fitness traits were similar in unselected and selected hybrid strains. Using a new method to examine the inheritance of resistance, based on data from fitness cost experiments, it was estimated that pyriproxyfen resistance is controlled by two loci in the QC02‐R strain. CONCLUSION: The lack of fitness costs associated with pyriproxyfen resistance could promote the evolution of resistance in field populations with similar traits to QC02‐R. Copyright © 2008 Society of Chemical Industry     

近10年我国烟粉虱发生为害及防治研究进展

烟粉虱是我国重要农业害虫,近10年来我国烟粉虱发生为害呈现以下特点:烟粉虱的优势生物型/隐种由B型更替为Q型;传播植物病毒(如黄化曲叶病毒、番茄褪绿病毒)成为了烟粉虱重要的为害方式;烟粉虱抗药性问题逐渐突出;化学农药尤其新烟碱类杀虫剂的广泛使用是Q型烟粉虱取代B型烟粉虱的关键因素。烟粉虱的综合防控措施日益完善,抗药性治理与非化学防控措施受到重视,但是依靠农药的现状并未完全改变。本文综述了近10年来我国烟粉虱的发生为害及防治方面的概况,探讨了今后烟粉虱防控方面的研究内容。     

Gene expression in pyriproxyfen-resistant Bemisia tabaci Q biotype

Pyriproxyfen is a biorational insecticide that acts as a juvenile hormone (JH) analogue and disrupts insect development with an unknown molecular mode of action. Pyriproxyfen is one of the major insecticides used to control the whitefly Bemisia tabaci (Gennadius) and comply with integrated pest management (IPM) programmes, resulting in minimal effects on the environment, humans and beneficial organisms. During the last few years, resistance to pyriproxyfen has been observed in several locations in Israel, sometimes reaching a thousandfold or more. No information exists about the molecular basis underlying this resistance that may lead to understanding the mode of action of pyriproxyfen and developing molecular markers for rapid monitoring of resistance outbreaks. In this communication, a cDNA microarray from B. tabaci was used to monitor changes in gene expression in a resistant B. tabaci population. Based on statistical analysis, 111 expressed sequence tags (ESTs) were identified that were differentially upregulated in the resistant strain after pyriproxyfen treatment. Many of the upregulated ESTs observed in the present study belong to families usually associated with resistance and xenobiotic detoxification such as mitochondrial genes, P450s and oxidative stress, genes associated with protein, lipid and carbohydrate metabolism and others related to JH-associated processes in insects such as oocyte and egg development.     

不同寄主种群B型烟粉虱体内营养和成虫体长差异比较

［目的］ 探讨以黄瓜、番茄、棉花及甘蓝4种不同植物为寄主对B型烟粉虱体内主要营养物质及成虫体长的影响。［方法］ 以长期隔离饲养的4个B型烟粉虱寄主种群为材料,测定不同寄主种群身体含水量、总糖、总脂、总蛋白及成虫体长,比较不同种群上述各项指标的差异。 ［结果］ 4个不同寄主种群B型烟粉虱体内总糖和总脂肪含量存在显著差异,而含水量和总蛋白含量差异不显著。总糖含量以棉花种群最高,占干重的9.62%;而黄瓜种群总糖含量最低,占干重的6.15%。总脂肪含量以棉花种群最高,占干重的49.57%;而番茄种群仅占干重的34.96%,含量最低。不同寄主植物对B型烟粉虱成虫的体长影响显著。雌成虫体长变化表现为：黄瓜种群>番茄种群>棉花种群>甘蓝种群;而雄虫体长变化为: 黄瓜种群>棉花种群>甘蓝种群>番茄种群。［结论］ 不同寄主植物对B型烟粉虱体内总糖、总脂含量及成虫体长有明显影响。     

Cotton whitefly (Bemisia tabaci) resistance to organophosphate and pyrethroid insecticides in Pakistan

Resistance to three organophosphate and four pyrethroid insecticides was monitored from 1992 to 2000 in field populations of adult whiteflies, Bemisia tabaci, from Pakistan using a leaf-dip method. There was generally a very high resistance to dimethoate and deltamethrin, and a moderate resistance to monocrotophos during 1992 to 1996. From 1997 to 2000, resistance to these insecticides dropped to low levels because of less reliance on them for whitefly control, and introduction of new chemistries with novel modes of action that had no cross-resistance to conventional insecticides. Concurrently, whitefly resistance to acephate, fenpropathrin, lambda-cyhalothrin and bifenthrin mostly remained low. An insecticide resistance management strategy is recommended that particularly emphasizes the rotation of still-effective insecticides from different chemical classes along with the use of novel chemicals and other tactics of integrated pest management.     

7种杀虫剂对北京地区烟粉虱成虫毒力的比较研究

本试验比较测定了7种杀虫剂对北京地区烟粉虱成虫的毒力,以期为北京地区高毒农药淘汰提供参考。结果表明:氟虫腈对烟粉虱成虫的毒力最强,其LC50值为2.98(g/mL;新烟碱类杀虫剂啶虫脒、吡虫啉对烟粉虱成虫的生物活性较好,LC50值分别为8.04(g/mL、7.49(g/mL,噻虫嗪对烟粉虱成虫毒力相对较差,LC50值仅为95.03(g/mL;烟粉虱成虫对马拉硫磷、异丙威和噻嗪酮3种杀虫剂不敏感。在北京地区,采用噻虫嗪、马拉硫磷、异丙威和噻嗪酮等杀虫剂,不能有效防治烟粉虱的成虫;氟虫腈、吡虫啉和啶虫脒可以用来防治烟粉虱成虫。     

B型烟粉虱对12个大豆品种的选择及适生性研究

在温度(26±1)℃、湿度60%～70%、光周期L∥D=14h∥10h的试验条件下,研究了B型烟粉虱对12个大豆品种的选择性以及这些品种对其生长发育、繁殖、存活和种群增长的影响。结果表明,B型烟粉虱对12个大豆品种的选择性有明显差异,其中对3618-4和浙春3号有很强的选择性,而对辽鲜1号的选择性最弱;此外,B型烟粉虱在不同大豆品种上的适生性也存在显著差异,其中在3618-4和浙春3号上的生存和繁殖适合性最高,即抗虫性最弱,而在辽鲜1号和5702上的生存和繁殖适合性最低,即抗虫性最强。     

Susceptibility to insecticides in the Q biotype of Bemisia tabaci is correlated with bacterial symbiont densities

BACKGROUND: The presence of symbiotic microorganisms may influence an insect's ability to tolerate natural and artificial stress agents such as insecticides. The authors have previously shown that Rickettsia in the B biotype of the whitefly Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) increases this insect's susceptibility to several insecticidal compounds. This communication reports a comparison of the susceptibilities of three isofemale strains of the Q biotype of B. tabaci harbouring different bacterial complements to major insecticides from different chemical groups: one strain harboured only Arsenophonus, one harboured Rickettsia and Arsenophonus and one harboured Arsenophonus and Wolbachia. RESULTS: The presence of different symbiont combinations in the three strains had a significant influence on their susceptibility to most of the insecticides tested. Thiamethoxam, imidacloprid, pyriproxyfen and spiromesifen had a significant influence on strains that had the double infections Rickettsia–Arsenophonus and Wolbachia–Arsenophonus, which also carried higher amounts of symbionts as assessed by quantitative real‐time PCR. No significant differences in mortality rates were observed when the tested strains were treated with diafenthiuron. CONCLUSION: The results suggest a correlation between the presence of high bacterial densities in B. tabaci and the insect's ability to detoxify toxic compounds such as insecticides. Copyright © 2009 Society of Chemical Industry     

Cross‐resistance,inheritance and biochemical mechanisms of imidacloprid resistance in B‐biotype Bemisia tabaci

BACKGROUND: The B‐type Bemisia tabaci (Gennadius) has become established in many regions in China, and neonicotinoids are extensively used to control this pest. Imidacloprid resistance in a laboratory‐selected strain of B‐type B. tabaci was characterised in order to provide the basis for recommending resistance management tactics. RESULTS: The NJ‐Imi strain of B‐type B. tabaci was selected from the NJ strain with imidacloprid for 30 generations. The NJ‐Imi strain exhibited 490‐fold resistance to imidacloprid, high levels of cross‐resistance to three other neonicotinoids, low levels of cross‐resistance to monosultap, cartap and spinosad, but no cross‐resistance to abamectin and cypermethrin. Imidacloprid resistance in the NJ‐Imi strain was autosomal and semi‐dominant. It is shown that enhanced detoxification mediated by cytochrome‐P450‐dependent monooxygenases contributes to imidacloprid resistance to some extent in the NJ‐Imi strain. Results from synergist bioassays and cross‐resistance patterns indicated that target‐site insensitivity may be involved in imidacloprid resistance in the NJ‐Imi strain of B. tabaci. CONCLUSION: Although oxidative detoxification mediated by P450 monooxygenases is involved in imidacloprid resistance in the NJ‐Imi strain of B‐type B. tabaci, target‐site modification as an additional resistance mechanism cannot be ruled out. Considering the high risk of cross‐resistance, neonicotinoids should be regarded as a single group when implementing an insecticide rotation scheme in B. tabaci control. Copyright © 2009 Society of Chemical Industry     

不同温度锻炼对高温胁迫下Q型烟粉虱存活及生殖的影响

［目的］ 明确不同温度锻炼对高温胁迫下Q型烟粉虱存活及生殖的影响。［方法］ 将Q型烟粉虱成虫在45 ℃下暴露1 h直接进行高温胁迫,及温度锻炼后再胁迫,即在不同温度(10、33、39 ℃)下暴露0.5 h,再45 ℃处理1 h,然后在26 ℃条件下饲养,观察其存活率、寿命及产卵量。 ［结果］ 在产卵量无明显变化时,低温锻炼后雌雄虫寿命缩短,以存活率升高的方式维持其种群。高温锻炼后存活率降低,以延长雌虫寿命的方式,使其种群数量维持在一定水平。［结论］ 不同温度锻炼后,Q型烟粉虱的种群动态与存活率、寿命、产卵量的变化之间存在着权衡。