Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.
College of Chemistry, Central China Normal University, Wuhan 430079, China.
Pestic Biochem Physiol. 2020 Jun;166:104564. doi: 10.1016/j.pestbp.2020.104564. Epub 2020 Mar 21.
Frankliniella occidentalis, the western flower thrips, is one of most notorious pests on a variety of crops worldwide and many populations have high resistance to different types of insecticides. In order to determine the susceptibility of F. occidentalis to the insecticide pyridalyl in the field and to understand the potential mechanism of resistance, we conducted field monitoring of resistance and investigated cross-resistance, fitness cost, and synergism for the 75.8-fold pyridalyl-resistant strain (PY-R) established with a long-term successive laboratory selection. The results showed that all field populations of F. occidentalis had high susceptibility to pyridalyl from 2016 to 2017. The PY-R strain showed no cross-resistance to spinosad, spinetoram, abamectin, imidacloprid, or pyriproxyfen. Tests of synergism demonstrated that piperonyl butoxide (PBO) and diethyl maleate (DEM) significantly inhibited pyridalyl resistance in the PY-R strain. Moreover, PY-R showed lower pupation and emergence rates than the susceptible strain (XY-S), and female fecundity was also significantly lower in PY-R than in XY-S. By calculating the net replacement rate (R) of XY-S, the fitness of PY-R was established as 0.52. In conclusion, the susceptibility of F. occidentalis to pyridalyl is still high in China, but resistance could be developed by successive-generation selections. Enhanced metabolic detoxification is possibly involved in resistance in PY-R, which caused significant fitness costs. Thus, pyridalyl will likely prove useful in the field for controlling F. occidentalis in China, and development of resistance could be delayed by rotating pyridalyl with other chemical agents lacking cross-resistance.
西方花蓟马，又称美州斑潜蝇，是世界范围内多种作物上最著名的害虫之一，许多种群对不同类型的杀虫剂都具有高抗性。为了确定田间法尼烯对杀虫剂吡啶的敏感性，以及了解抗性的潜在机制，我们对通过长期连续实验室选择建立的 75.8 倍抗性品系（PY-R）进行了田间抗性监测，并调查了交叉抗性、适合度成本和增效作用。结果表明，2016 年至 2017 年，所有田间种群的法尼烯对吡啶都具有高敏感性。PY-R 品系对多杀菌素、乙基多杀菌素、阿维菌素、氯吡脲或吡丙醚没有交叉抗性。增效作用测试表明，增效醚（PBO）和马来酸二乙酯（DEM）显著抑制了 PY-R 品系对吡啶的抗性。此外，PY-R 的化蛹率和羽化率均低于敏感品系（XY-S），且 PY-R 的雌虫繁殖力也明显低于 XY-S。通过计算 XY-S 的净替代率（R），确定了 PY-R 的适合度为 0.52。综上所述，在中国，法尼烯对吡啶的敏感性仍然很高，但通过连续世代选择可能会产生抗性。增强的代谢解毒可能参与了 PY-R 的抗性，这导致了显著的适合度成本。因此，吡啶在田间控制中国的美州斑潜蝇可能会很有用，通过与其他缺乏交叉抗性的化学药剂轮用可以延缓抗性的发展。
