Abstract Plutella xylostella (L.), commonly known as diamondback moth, is one of the most important pests of Brassicaceae in Brazil. This study aimed to assess the susceptibility of P. xylostella and pattern of resistance inheritance to lufenuron, an insect growth regulator (IGR) that impairs the insect molting, as well as the cross-resistance to methoxyfenozide (Nonsteroidal ecdysone agonist). Concentration-mortality bioassays were performed using the leaf dipping method towards field collected populations and genotypes used in the genetic crossings. Populations of this pest, from the mesoregion of Pernambuco (Brazil), were highly resistant to lufenuron. The recommended concentration of lufenuron caused more than 80% mortality of larvae of two populations [Piedade (PDD) and Recife (REC-S)]. Methoxyfenozide caused more than 80% mortality of larvae of all assessed populations, suggesting no cross-resistance between insect growth regulators. The population of Bezerros (BZR-R) was the most resistant (11,283-fold) to lufenuron compared with REC-S population (standard reference). Resistance to lufenuron was inherited as autosomal, incompletely recessive, and monofactorial trait, suggesting that a single gene or a set of genes tightly linked is involved in resistance. Methoxyfenozide is an alternative molecule suggested for the control of P. xylostella in areas where resistance to lufenuron has evolved. Furthermore, information provided in this work should fine-tune insecticide resistance management (IRM) programs to delay the evolution of resistance to chitin synthesis inhibitors like lufenuron, where resistance frequency is incipient.

中文翻译：

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小菜蛾（鳞翅目：小菜蛾科）对虱螨脲的田间抗性：对甲氧虫酰肼的遗传和缺乏交叉抗性

摘要 Plutella xylostella (L.)，俗称小菜蛾，是巴西十字花科最重要的害虫之一。本研究旨在评估小菜蛾的易感性和对虱螨脲（一种损害昆虫蜕皮的昆虫生长调节剂 (IGR)）的抗性遗传模式，以及对甲氧虫酰肼（非甾体蜕皮激素激动剂）的交叉抗性。使用浸叶法对田间收集的种群和遗传杂交中使用的基因型进行浓度-死亡率生物测定。这种来自伯南布哥（巴西）中部地区的害虫种群对虱螨脲具有高度抗性。推荐浓度的虱螨脲导致两个种群 [Piedade (PDD) 和 Recife (REC-S)] 的幼虫死亡率超过 80%。Methoxyfenozide 导致所有评估种群的幼虫死亡率超过 80%，表明昆虫生长调节剂之间没有交叉抗性。与 REC-S 群体（标准参考）相比，Bezerros (BZR-R) 群体对虱螨脲的耐药性最高（11,283 倍）。对虱螨脲的抗性以常染色体、不完全隐性和单因素性状遗传，表明单个基因或一组紧密连锁的基因与抗性有关。Methoxyfenozide 是一种替代分子，建议用于在对虱螨脲产生抗性的地区控制小菜蛾。此外，这项工作中提供的信息应该微调杀虫剂耐药性管理 (IRM) 程序，以延迟对甲壳素合成抑制剂（如虱螨脲）的耐药性的演变，在这种情况下，耐药性频率刚刚开始。