Baseline susceptibility of spotted wing Drosophila (Drosophila suzukii) to four key insecticide classes

BACKGROUND

The invasive drosophilid pest, Drosophila suzukii Matsumura, is affecting berry production in most fruit‐producing regions of the world. Chemical control is the dominant management approach, creating concern for insecticide resistance in this pest. We compared the insecticide susceptibility of D. suzukii populations collected from conventional, organic or insecticide‐free blueberry sites.

RESULTS

The sensitivity of D. suzukii to malathion and spinetoram declined slightly across the 3 years of monitoring, whereas it was more consistent for methomyl and zeta‐cypermethrin. The sensitivity of D. suzukii to all four insecticides (LC₅₀ and LC₉₀ values) did not differ significantly among the blueberry fields using different management practices.

CONCLUSIONS

The baseline sensitivity of D. suzukii has been characterized, allowing future comparisons if field failures of chemical control are reported. The concentration achieving high control indicates that effective levels of control can still be achieved with field rates of these four insecticides. However, declining susceptibility of some populations of D. suzukii to some key insecticides highlights the need for resistance monitoring. © 2017 Society of Chemical Industry     

斑翅果蝇的PCR-RFLP快速鉴定方法

应用PCR-RFLP技术分析斑翅果蝇及其相关种间的差异。选用果蝇COI基因通用引物并通过PCR扩增斑翅果蝇、亚艳丽果蝇等11种15个样品COI基因序列,对PCR产物进行回收和测序,根据测序结果及NCBI上序列比对结果,选用限制性内切酶ApaⅠ和HinfⅠ分别对果蝇COI基因PCR产物进行酶切,酶切产物经琼脂糖电泳分析。结果表明:同时使用ApaⅠ和HinfⅠ酶,可以将斑翅果蝇与其他种相区分。根据果蝇COI基因建立的PCR-RFLP技术可对斑翅果蝇快速、准确进行鉴定。     

日本细毛环腹瘿蜂对斑翅果蝇的寄生效能

日本细毛环腹瘿蜂Leptopilina japonica是斑翅果蝇Drosophila suzukii的优势寄生性天敌之一, 对斑翅果蝇具有良好的生防潜力。为更好地利用日本细毛环腹瘿蜂防控斑翅果蝇, 本研究在室内观察了日本细毛环腹瘿蜂的行为活动和生长发育特征。采用室内接虫法研究了该蜂对斑翅果蝇2龄幼虫的寄生能力。分别运用Holling Ⅱ型圆盘方程、搜寻效应方程和Hassell-Varley模型拟合分析了日本细毛环腹瘿蜂的寄生功能反应、搜寻效应和自身密度干扰效应。结果表明:日本细毛环腹瘿蜂的寄生功能反应符合Holling Ⅱ模型, 其拟合方程为:Na=0.70N/(1+0.03N); 寄生效能(a/Th)为15.78; 在一定空间内, 寄生蜂的寄生量随寄主密度增加而增大, 至寄主密度达25头/罐后寄生量趋于平稳; 寄生蜂的搜寻效应随着寄主密度的增加而减弱; 当斑翅果蝇的密度分别为10、20、30头/罐时寄生蜂自身密度干扰模型分别为E10=0.487 8P-0.871 3; E20=0.442 0P-0.676 8和E30=0.346 2P-0.433 7, 在同一寄主密度下, 日本细毛环腹瘿蜂的寻找效应均随自身密度的增加而减弱。日本细毛环腹瘿蜂对斑翅果蝇2龄幼虫具有较好的寄生效能, 但寄主密度较大会导致日本细毛环腹瘿蜂的寄生效能减弱, 随着寄生蜂自身密度的增加, 其种内个体间会出现干扰作用。     

几种杀虫剂对斑翅果蝇室内毒力测定

在实验室条件下,选取6种常用杀虫剂,采用胃毒触杀联合毒力测定方法测定了室内成虫种群对这几种药剂的敏感性。毒力测定结果表明:藜芦碱、高效氯氟氰菊酯、氯氰菊酯的毒力相对较高,而阿维菌素、氟虫腈、异丙威的毒力较低。藜芦碱、高效氯氟氰菊酯、氯氰菊酯可作为防治斑翅果蝇的候选药剂。     

果蝇诱捕器诱捕杨桃桔小实蝇的效果观察

应用果蝇诱捕器能有效诱捕杨桃果园的桔小实蝇,且具专一性,对其它害虫及天敌无效,具安全、有效、简便、经济、实用、生态环保的优点。可在生产中应用。     

铃木氏果蝇对不同品种蓝莓为害情况调查

在我国蓝莓是重要的浆果类作物, 而铃木氏果蝇对蓝莓的为害特征及为害程度尚无报道?本研究通过诱捕器监测蓝莓园中成虫的种群发生动态, 并采用随机取样法每周调查‘瑞卡’‘北陆’‘美登’和‘蓝金’4个蓝莓品种的果实受害率, 同时研究了受害果实内幼虫取食为害蓝莓的持续期?在连续13周的诱捕调查中, 共捕获到9 999头铃木氏果蝇, 其诱捕高峰期是8月22日, 首次诱捕到成虫是7月13日, 而通过采样首次调查到受害果是7月24日?表明诱捕器能够有效监测铃木氏果蝇的种群动态变化, 并提前11 d预警果实受害?各品种果实成熟初期受害率均很低?仅为0~2%, 然而随着果实成熟度增加受害率均明显增加, 其中‘美登’受害率最低为34%, 而其他3个品种的受害率均高于80%, ‘蓝金’最高, 达90%?25℃条件下, 铃木氏果蝇所产卵次日即发育为幼虫, 且持续8 d后仍为幼虫在果实内为害, 可见蓝莓果实一旦被害即使采摘也无法避免损失?     

Non-steroidal inhibitors of Drosophila melanogaster steroidogenic glutathione S-transferase Noppera-bo

Insect growth regulators (IGRs) can be developed by elucidating the molecular mechanisms of insect-specific biological events. Because insect molting, and metamorphosis are controlled by ecdysteroids, their biosynthetic pathways can serve as targets for IGR development. The glutathione S-transferase Noppera-bo (Nobo), which is conserved in dipteran and lepidopteran species, plays an essential role in ecdysteroid biosynthesis. Our previous study using 17β-estradiol as a molecular probe revealed that Asp113 of Drosophila melanogaster Nobo (DmNobo) is essential for its biological function. However, to develop IGRs with a greater Nobo inhibitory activity than 17β-estradiol, further structural information is warranted. Here, we report five novel non-steroidal DmNobo inhibitors. Analysis of crystal structures of complexes revealed that DmNobo binds these inhibitors in an Asp113-independent manner. Among amino acid residues at the substrate-recognition site, conformation of conserved Phe39 was dynamically altered upon inhibitor binding. Therefore, these inhibitors can serve as seed compounds for IGR development.     

基于最大熵模型的斑翅果蝇适生性研究

斑翅果蝇(Drosophila suzukii)是重要的水果果实害虫,近年来在全球的扩散、为害备受关注。为防控斑翅果蝇入侵,保护我国果品生产安全,采用最大墒模型(MaxEnt)与ArcGIS相结合的技术模式,在收集、整理斑翅果蝇全球地理分布信息及筛选气候变量的基础上,预测了当前及未来气候条件下该虫在全球及我国的适生区分布。结果表明,在当前气候条件下,斑翅果蝇在全球的适生范围较广、适生程度较高;我国适生区面积比为61.68%,其中,高度适生区、中度适生区和低度适生区面积比分别为7.59%、27.81%和26.28%,在2050年RCP26和RCP85的气候条件下,斑翅果蝇在全球及我国的适生范围和适生程度均呈扩大趋势,其适生区北界向北拓展。建议有关部门加强针对斑翅果蝇虫情监测、综合治理及出口检疫的工作力度。     

Reduced spray programs for Drosophila suzukii management in berry crops

Since the arrival of Drosophila suzukii M. (Diptera: Drosophilidae), field applications of broad-spectrum insecticides have increased in berry crop production to protect susceptible fruits from infestation. Field studies were conducted from 2011 to 2013 to determine whether alternate row middle or border spray programs could manage D. suzukii as well as complete sprays and have less of an impact on non-target arthropods. Four raspberry sites and one blueberry site were alternate row middle and border sprayed, respectively. Adult and larva counts of D. suzukii were compared to conventional complete spray programs. Non-target arthropods were evaluated 7 d post-harvest. In both reduced spray trials, no differences in mean adult numbers and larvae of D. suzukii were detected between treatments. Mean counts immediately after sprays (i.e. 3–12 d after treatment) were also similar in complete and alternate row sprays. Both reduced spray strategies had significantly more Stethorus spp.; additionally, alternate row sprays had significantly more Psyllobora spp. These reduced pesticide strategies are additional tools to consider in D. suzukii IPM programs that can reduce the area sprayed, application time, and input costs while conserving natural enemies.     

果蝇Toll和IMD信号通路中的功能结构域

功能结构域在蛋白相互关系中起着重要的作用,在细胞信号通路中,上、下游信号分子结构域间的相互作用,传递着信号。赖氨酸型肽聚糖(Lys-type PGN)(来自革兰氏阳性菌)和β-1,3葡聚糖(β-1,3 glucan)(来自真菌)激活果蝇Toll信号通路;二氨基庚二酸型肽聚糖(DAP-type PGN)和脂多糖粗多糖(LPS)(来自革兰氏阴性菌)激活果蝇IMD信号通路。本文以信号通路为线索,完整地展示各信号分子功能结构域间的相互作用关系,阐述两个信号通路分别降解细胞质中的Cactus和Relish,释放出NF-kB蛋白进入到细胞核的全过程。     

Factors influencing oviposition behaviour of the invasive pest,Drosophila suzukii,derived from interactions with other Drosophila species: potential applications for control

Drosophila suzukii (Matsumura) or spotted wing Drosophila is a worldwide invasive pest of soft- and stone-fruit production. Female D. suzukii lay their eggs in ripening fruit and the hatched larvae damage fruit from the inside, rendering it unmarketable and causing significant economic loss. Current methods to reduce D. suzukii population in the field primarily rely on chemical insecticides which are not a sustainable long-term solution and increase the risk of resistance developing. Several studies demonstrate that when D. suzukii encounter or coexist with other Drosophila on a food source, this is usually a disadvantage to D. suzukii, leading to reduced oviposition and increased larval mortality. These effects have potential to be exploited from a pest management perspective. In this review we summarise recent research articles focusing on the interspecific interactions between D. suzukii and other Drosophila species aimed at understanding how this drives D. suzukii behaviour. Potential semiochemical and microbiome impacts are postulated as determinants of D. suzukii behaviour. Development of control practices focusing on reducing D. suzukii populations and deterring them from laying eggs by utilising factors that drive their behaviour are discussed. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

拟果蝇钠离子通道基因克隆及其生物信息学分析

本文采用RT-PCR技术克隆获得了拟果蝇Drosophila simulans电压门控钠离子通道基因序列,明确其典型特征,分析了进化关系,为拟果蝇抗性分子机理研究奠定基础。克隆得到拟果蝇钠离子通道开放阅读框（GenBank登录号为MT113357）,长为6270 bp,编码2090个氨基酸。通过生物信息学分析,发现拟果蝇与黑腹果蝇Drosophila melanogaster钠离子通道基因相似度高达96.86%,与家蝇Musca domestica钠离子通道基因相似度达88.75%,在进化起源上与双翅目果蝇属昆虫有极高的相似度。所克隆出的序列符合昆虫钠离子通道的基本特征,具有DEKA模块和疏水性失活闸门MFM。获得三个选择性剪接（i、a、b）和17个RNA编辑。本文成功克隆拟果蝇钠离子通道基因,对拟果蝇钠离子通道基因进行分析,为研究其抗性机理奠定基础,为农业生产新型药剂的开发提供了新思路。     

Homology modelling of Drosophila cytochrome P450 enzymes associated with insecticide resistance

BACKGROUND: Overexpression of the cytochrome P450 gene Cyp6g1 confers resistance against DDT and a broad range of other insecticides in Drosophila melanogaster Meig. In the absence of crystal structures of CYP6G1 or complexes with its substrates, structural studies rely on homology modelling and ligand docking to understand P450–substrate interactions. RESULTS: Homology models are presented for CYP6G1, a P450 associated with resistance to DDT and neonicotinoids, and two other enzymes associated with insecticide resistance in D. melanogaster, CYP12D1 and CYP6A2. The models are based on a template of the X‐ray structure of the phylogenetically related human CYP3A4, which is known for its broad substrate specificity. The model of CYP6G1 has a much smaller active site cavity than the template. The cavity is also ‘V’‐shaped and is lined with hydrophobic residues, showing high shape and chemical complementarity with the molecular characteristics of DDT. Comparison of the DDT–CYP6G1 complex and a non‐resistant CYP6A2 homology model implies that tight‐fit recognition of this insecticide is important in CYP6G1. The active site can accommodate differently shaped substrates ranging from imidacloprid to malathion but not the pyrethroids permethrin and cyfluthrin. CONCLUSION: The CYP6G1, CYP12D1 and CYP6A2 homology models can provide a structural insight into insecticide resistance in flies overexpressing P450 enzymes with broad substrate specificities. Copyright © 2010 Society of Chemical Industry     

甲醛对果蝇发育和繁殖的影响

甲醛已被广泛用于人们的日常生活中,成为室内环境的主要污染源。为探讨甲醛对动物不同发育阶段的毒性,本文以模式生物果蝇Drosophila melanogaster为对象,研究了饲料中添加不同浓度甲醛对果蝇生长发育的影响。结果显示,当对照组发育至3龄幼虫(孵化后3d)时,与未添加甲醛的对照组相比,饲料中添加0.25%或0.50%的甲醛极显著降低了幼虫的体重(P<0.01),添加了0.50%甲醛的饲料组中发育出来的雌、雄成蝇体重也显著低于对照组,其中雌虫体重的差异达到极显著水平。此外,饲料中添加甲醛,还显著延长了幼虫发育的时间,即从胚胎到化蛹的发育时间、胚胎到羽化的发育时间都极显著长于对照组(P<0.01),而其蛹期变态发育时间在对照组和各实验组之间没有显著差异。饲料中添加甲醛,还极显著降低了果蝇的产卵量(P<0.01)。综上结果表明,饲料中含有甲醛可显著降低果蝇的发育速度,影响果蝇的生长和繁殖力,但对果蝇蛹期变态发育过程没有显著影响。