Rabelo Marcelo M, Santos Izailda B, Paula-Moraes Silvana V
West Florida Research and Education Center, Department of Entomology and Nematology, University of Florida, Jay, FL 32565, USA.
Insects. 2022 Apr 8;13(4):365. doi: 10.3390/insects13040365.
In the United States, beet armyworm resistance to both chlorantraniliprole and bifenthrin insecticides was first reported in 2020. Here we examined beet armyworm fitness and stability of resistance to chlorantraniliprole and pyrethroid insecticides since knowledge of the stability of resistance is a crucial aspect when recommending rotation of insecticides with different mode of action. Concentration-mortality bioassays were performed with field and laboratory susceptible populations. The F2, F13, and F27 generations of the field-derived population, maintained in the laboratory without insecticide, were exposed to commercial formulations of bifenthrin and chlorantraniliprole using the leaf-dip bioassay method (IRAC n. 007). Insects from F27 had the fitness components (survival, body weight, development time) documented and compared by LSM in each insecticide concentration tested. The resistance ratio to chlorantraniliprole reached 629, 80, 15-fold at F2, F13, and F27, respectively. These results contrast with an over 1000-fold resistance ratio to bifenthrin in all generations. The field-derived population had fitness reduced by chlorantraniliprole, but not by bifenthrin. In summary, the resistance of beet armyworm to bifenthrin was stable with no shift in fitness. In contrast, resistance to chlorantraniliprole was not stable through the generations kept in the laboratory without selection pressure, likely due to fitness cost.
2020年，美国首次报道甜菜夜蛾对氯虫苯甲酰胺和联苯菊酯杀虫剂产生抗性。鉴于抗性稳定性是推荐轮换使用不同作用方式杀虫剂时的一个关键因素，我们在此研究了甜菜夜蛾对氯虫苯甲酰胺和拟除虫菊酯类杀虫剂的适应性及抗性稳定性。使用田间和实验室敏感种群进行浓度-死亡率生物测定。通过叶浸法（IRAC编号007），将在实验室中未接触杀虫剂饲养的田间种群的F2、F13和F27代暴露于联苯菊酯和氯虫苯甲酰胺的商业制剂中。记录并通过最小二乘法均值（LSM）比较F27代昆虫在每个测试杀虫剂浓度下的适应性指标（存活率、体重、发育时间）。对氯虫苯甲酰胺的抗性倍数在F2、F13和F27代分别达到629、80和15倍。这些结果与所有世代对联苯菊酯超过1000倍的抗性倍数形成对比。田间种群的适应性受到氯虫苯甲酰胺的影响，但未受联苯菊酯影响。总之，甜菜夜蛾对联苯菊酯的抗性稳定，适应性无变化。相比之下，在没有选择压力的实验室饲养世代中，对氯虫苯甲酰胺的抗性不稳定，这可能是由于适应性代价所致。
