The diamondback moth (DBM), Plutella xylostella (L.), is a major pest affecting cruciferous vegetables, and seriously affects the quality and yield of these vegetables. Diafenthiuron is a traditional thiourea-based insecticide, but it is rarely used to control pests on cruciferous vegetables due to its phytotoxicity on these vegetables under high temperature and light conditions. Thus, there is an ongoing need for more effective pesticides that can be used on cruciferous vegetables, possibly including new formulations of diafenthiuron. A new thiourea insecticide, methylthio-diafenthiuron, is intended to optimize the structure of diafenthiuron not only to preserve its insecticidal bioactivity but also to overcome its phytotoxicity to cruciferous vegetables, aiming to control insect pests on cruciferous vegetables. In this study, we compared the toxicity of methylthio-diafenthiuron to some frequently used insecticides on the third-instar larvae of DBM. The parental pupal duration was significantly longer under the treatment than in the control, but the pupal weight, fecundity, and hatching rate significantly decreased. By studying the changes in three detoxifying enzymes within 72 h after treatment with a sublethal concentration, the activity of CarE and ODM in the treatment group significantly increased at first and then decreased. In addition, methylthio-diafenthiuron clearly inhibited three kinds of ATPases in the DBM and significantly reduced the eclosion rate of the pupae. This research provides valuable information for the assessment and rational application of methylthio-diafenthiuron for the control of pests on cruciferous vegetables.

中文翻译：

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甲硫基丁醚脲对小菜蛾 Plutella xylostella (L.) (Lepidoptera: Plutellidae) 生命表参数和酶学性质的亚致死作用

小菜蛾Plutella xylostella (L.)是危害十字花科蔬菜的主要害虫，严重影响十字花科蔬菜的品质和产量。杀螨隆是一种传统的硫脲类杀虫剂，但由于其在高温光照条件下对十字花科蔬菜有药害作用，因此很少用于防治十字花科蔬菜上的害虫。因此，一直需要可用于十字花科蔬菜的更有效的杀虫剂，可能包括新的杀螨隆制剂。一种新型硫脲类杀虫剂甲硫基丁醚脲旨在优化丁醚脲结构，既保持其杀虫生物活性，又克服其对十字花科蔬菜的药害，旨在防治十字花科蔬菜上的害虫。在这项研究中，我们比较了甲硫基丁醚脲与一些常用杀虫剂对 DBM 三龄幼虫的毒性。处理下的亲本蛹持续时间明显长于对照组，但蛹重、繁殖力和孵化率显着降低。通过研究亚致死浓度治疗后72 h内三种解毒酶的变化，治疗组CarE和ODM的活性先升高后降低。此外，甲硫基丁醚脲可明显抑制 DBM 中的三种 ATP 酶，并显着降低蛹的羽化率。本研究为评估和合理应用甲硫脲在十字花科蔬菜病虫害防治中的应用提供了有价值的信息。