Center for Ecology and Conservation, Biosciences, University of Exeter, Penryn Campus, Penryn, UK.
Syngenta Crop Protection AG, Stein, Switzerland.
Pest Manag Sci. 2024 Feb;80(2):498-507. doi: 10.1002/ps.7778. Epub 2023 Oct 17.
Plutella xylostella (L.) is a destructive pest of cruciferous crops worldwide that has evolved resistance to many insecticides. Here we examined the mode of inheritance, cross-resistance profile, and potential mechanisms of emamectin benzoate resistance in a field-derived strain of P. xylostella from Japan.
A field-collected population of P. xylostella, was found to exhibit strong (> 150-fold) resistance to emamectin benzoate in insecticide bioassays when compared with a laboratory susceptible strain. Genetic analysis showed that resistance is inherited as an autosomal, recessive trait, and is conferred by a single or a few closely linked loci. The emamectin benzoate resistant strain also exhibited resistance to abamectin, lepimectin, chlorantraniliprole, lufenuron, spinetoram, indoxacarb, fipronil, dieldrin, endosulfan and lambda-cyhalothrin, demonstrating a remarkable multi-resistance profile. Insecticide bioassays employing inhibitors of detoxification enzymes revealed that piperonyl butoxide (PBO) increased the toxicity of emamectin benzoate in the resistant strain by ten-fold indicating the potential involvement of cytochrome P450 monooxygenases in avermectin resistance. Furthermore, cloning and sequencing of the primary receptor of avermectins, the GluCl channel, revealed the absence of target-site mutations in the resistant strain.
Our data on the mode of inheritance and mechanisms of resistance to emamectin benzoate in a P. xylostella strain from Japan provide a foundation for the development of regional resistance management strategies. However, the high levels of phenotypic resistance in this strain to a diverse range of other insecticide classes available for control illustrate the challenges associated with the sustainable control of this important pest. © 2023 Society of Chemical Industry.
小菜蛾（Plutella xylostella（L.））是一种在全球范围内对十字花科作物具有破坏性的害虫，已对许多杀虫剂产生了抗药性。在这里，我们研究了来自日本的田间小菜蛾种群对甲氨基阿维菌素苯甲酸盐的抗性遗传方式、交叉抗性谱和潜在机制。
与实验室敏感品系相比，田间采集的小菜蛾种群在杀虫剂生物测定中对甲氨基阿维菌素苯甲酸盐表现出很强的抗性（>150 倍）。遗传分析表明，抗性是由一个或少数几个紧密连锁的基因座隐性遗传的，且由一个或少数几个紧密连锁的基因座隐性遗传的。甲氨基阿维菌素苯甲酸盐抗性品系对阿维菌素、甲维盐、氯虫苯甲酰胺、灭幼脲、氯噻啉、茚虫威、氟虫腈、狄氏剂、硫丹和氯氟氰菊酯也表现出抗性，表现出显著的多抗性谱。采用解毒酶抑制剂的杀虫剂生物测定表明，增效醚（PBO）使甲氨基阿维菌素苯甲酸盐在抗性品系中的毒性增加了 10 倍，表明细胞色素 P450 单加氧酶可能参与了阿维菌素的抗性。此外，阿维菌素的主要受体 GluCl 通道的克隆和测序表明，在抗性品系中不存在靶标位点突变。
我们关于日本小菜蛾种群对甲氨基阿维菌素苯甲酸盐的抗性遗传方式和机制的研究结果为制定区域性抗性管理策略提供了基础。然而，该品系对其他可供防治的不同类别的杀虫剂表现出高水平的表型抗性，这说明了可持续控制这一重要害虫所面临的挑战。
