Diamondback moth (DBM), Plutella xylostella, is an important pest of crucifers worldwide. The extensive use of flubendiamide has led to the development of resistance in field populations and reports of control failures. In this study, the lab-selected (Rf) and field-collected (Rb) flubendiamide-resistant strains of P. xylostella with LC50 resistance ratios of 1890-fold and 1251-fold, respectively, were used, as well as a lab-reared flubendiamide-susceptible strain (S). The results showed that the fecundity of the Rf and Rb-resistant strains was significantly lower than that of S strain. The contents of vitellin and transcripts of P. xylostella vitellogenin (PxVg) and P. xylostella vitellogenin receptor (PxVgR) genes in the Rf and Rb strains were significantly higher than those of S strains at 0-48 h after adult eclosion. At 96 h after eclosion, the content of vitellin in the Rf and Rb strains did not differ significantly from those of S strains, whereas transcripts of the PxVg and PxVgR genes in the Rf and Rb strains were significantly lower than that of the S strain. The content of the juvenile hormone III (JH III), β-ecdysone (20E), and the gene expression level of P. xylostella methoprene tolerant (PxMet) in the Rf and Rb strains were significantly higher than that of the S strain. The activity of trehalase was significantly higher in the Rf and Rb strains than that of the S strain in the first to the third instar larvae, whereas in the fourth instar larvae, there was no significantly difference in the three strains. At different times after adult eclosion, the differences in trehalase activity were erratic between the strains. The transcripts of P. xylostella trehalase (PxTre) gene in the Rf and Rb strains were significantly higher than that of the S strain in most developmental stages. Here, we report differences in fecundity between flubendiamide-resistant and susceptible strains of P. xylostella and discuss gene expression of several reproductive factors, which provides a possible explanation for the mechanism of fecundity reduction concurrent with flubendiamide-resistance in P. xylostella.

中文翻译：

---

小菜蛾氟虫双酰胺耐药菌株繁殖力下降及生殖因子调控

小菜蛾(DBM)，Plutella xylostella，是世界范围内十字花科植物的重要害虫。氟虫双酰胺的广泛使用导致田间种群产生抗药性和控制失败的报告。在这项研究中，使用了实验室选择 (Rf) 和田间收集 (Rb) 氟虫双酰胺抗性小菜蛾菌株，LC50 抗性比分别为 1890 倍和 1251 倍，以及实验室-饲养的氟虫双酰胺敏感菌株（S）。结果表明，Rf和Rb抗性菌株的繁殖力显着低于S菌株。在成虫羽化后0-48小时，Rf和Rb株中小菜蛾卵黄蛋白原(PxVg)和小菜蛾卵黄素受体(PxVgR)基因的卵黄蛋白和转录物的含量显着高于S株。羽化后 96 h，Rf 和 Rb 菌株中的卵黄蛋白含量与 S 菌株的含量没有显着差异，而 Rf 和 Rb 菌株中 PxVg 和 PxVgR 基因的转录物显着低于 S 菌株。Rf和Rb菌株中保幼激素III（JH III）、β-蜕皮激素（20E）的含量以及小菜蛾耐甲虫（PxMet）基因表达水平均显着高于S菌株。1～3龄幼虫Rf、Rb株海藻糖酶活性显着高于S株，而4龄幼虫三株间海藻糖酶活性无显着差异。在成虫羽化后的不同时间，菌株之间海藻糖酶活性的差异是不稳定的。P的成绩单 在大多数发育阶段，Rf 和 Rb 菌株中的小菜蛾海藻糖酶 (PxTre) 基因显着高于 S 菌株。在这里，我们报告了小菜蛾的氟虫双酰胺耐药菌株和易感菌株之间繁殖力的差异，并讨论了几种繁殖因子的基因表达，这为小菜蛾在氟虫双酰胺耐药性同时导致繁殖力降低的机制提供了可能的解释。