Zhang Xiaohe, Su Sha, Jian Chengzhi, Huang Baojian, Zhang Jilong, Suo Jinbo, Peng Xiong, Chen Maohua
State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau of Ministry of Agriculture and Rural Affairs, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
J Econ Entomol. 2024 Dec 28;117(6):2636-2645. doi: 10.1093/jee/toae247.
Grapholita molesta (Busck) (Lepidoptera: Tortricidae) is a globally significant fruit pest traditionally managed using chemical insecticides such as lambda-cyhalothrin. However, repeated applications have led to the development of resistance in field populations. The mechanisms and fitness costs associated with lambda-cyhalothrin resistance in G. molesta remain poorly understood. In this study, we established a lambda-cyhalothrin-resistant strain (RS) of G. molesta through continuous selection with lambda-cyhalothrin in the laboratory for 21 generations, resulting in a 249.6-fold increase in resistance. Bioassay data from the F1 progeny (F1RS and F1SR) of reciprocal crosses between RS and susceptible strain (SS) showed similar degrees of dominance (0.40 for F1RS and 0.32 for F1SR). Significant differences between observed and expected mortalities of backcross individuals suggested that resistance to lambda-cyhalothrin is polygenic. Compared to the SS strain, the RS strain exhibited significantly prolonged periods of larval, prepupal, and pupal stages, as well as a significant decrease in larval weight. In addition, the RS strain showed significant reductions in fecundity, cumulative flight distance, maximum flight distance, cumulative flight time, maximum flight time, and average flight speed. These results suggest that resistance to lambda-cyhalothrin in G. molesta is autosomal, incompletely dominant, and polygenic. Life-history traits such as fecundity and flight capacity were significantly reduced in RS strains compared with the SS strain. These findings provide valuable insights for mitigating lambda-cyhalothrin resistance development and promoting sustainable control of G. molesta in the field.
梨小食心虫（Grapholita molesta (Busck)，鳞翅目：卷蛾科）是一种在全球范围内具有重要影响的水果害虫，传统上使用高效氯氟氰菊酯等化学杀虫剂进行防治。然而，反复使用这些杀虫剂导致田间种群产生了抗性。目前，对于梨小食心虫对高效氯氟氰菊酯抗性的机制以及与之相关的适合度代价仍知之甚少。在本研究中，我们通过在实验室中用高效氯氟氰菊酯连续筛选21代，建立了一个梨小食心虫的高效氯氟氰菊酯抗性品系（RS），其抗性提高了249.6倍。抗性品系（RS）与敏感品系（SS）正反交的F1代子代（F1RS和F1SR）的生物测定数据显示，显性程度相似（F1RS为0.40，F1SR为0.32）。回交个体的观察死亡率与预期死亡率之间存在显著差异，这表明梨小食心虫对高效氯氟氰菊酯的抗性是多基因的。与敏感品系相比，抗性品系的幼虫期、预蛹期和蛹期显著延长，幼虫体重显著降低。此外，抗性品系的繁殖力、累计飞行距离、最大飞行距离、累计飞行时间、最大飞行时间和平均飞行速度均显著降低。这些结果表明，梨小食心虫对高效氯氟氰菊酯的抗性是常染色体遗传、不完全显性且为多基因的。与敏感品系相比，抗性品系的繁殖力和飞行能力等生活史特征显著降低。这些发现为减缓高效氯氟氰菊酯抗性的发展以及促进田间梨小食心虫的可持续防治提供了有价值的见解。
