USDA-ARS, Southern Insect Management Research Unit, Stoneville, MS 38776, USA.
USDA-ARS, Southern Insect Management Research Unit, Stoneville, MS 38776, USA.
Comp Biochem Physiol C Toxicol Pharmacol. 2024 Jan;275:109765. doi: 10.1016/j.cbpc.2023.109765. Epub 2023 Oct 14.
In the southern United States, neonicotinoids are commonly applied as foliar insecticides to control sucking insect pests, such as the tarnished plant bug (TPB, Lygus lineolaris). In this study, spraying bioassays were conducted to determine the toxicity of five neonicotinoids and sulfoxaflor to susceptible and late fall field-collected TPB adults from Mississippi Delta region. Compared to a susceptible population, the field-collected TPBs exhibited the highest resistance to imidacloprid (up to 19.5-fold), a moderate resistance to acetamiprid (9.43-fold), clothianidin (13.68-fold), thiamethoxam (7.88-fold) and the least resistance to thiacloprid (4.61-fold) and sulfoxaflor (1.82-fold), respectively. A synergist study demonstrated that piperonyl butoxide (PBO) significantly increased the toxicity of imidacloprid and thiamethoxam by 22.2- and 15.3-fold, respectively, while triphenyl phosphate (TPP) and diethyl maleate (DEM) only showed 2-3-fold synergism to both neonicotinoids. In the field-collected TPBs, activities of the three detoxification enzymes esterase, glutathione S-transferase (GST) and CYP450 monooxygenase (P450) were significantly increased by 3.43-, 1.48- and 2.70-fold, respectively, when compared to the susceptible population. Additionally, after 48 h exposure to imidacloprid or thiamethoxam, resistant TPB adults exhibited elevated esterase activities, decreased GST activities, and no significant changes in P450 activities. Further examinations revealed that the expression of certain esterase and P450 detoxification genes were significantly elevated in resistant TPBs. Overall, these results suggest that elevated esterase and P450s expression and enzyme activity are key mechanisms for metabolic resistance in TPBs to neonicotinoids. Our findings also provide valuable information for selection and adoption of neonicotinoid insecticides for resistance management of TPBs and minimizing toxic risk to foraging bees.
在美国南部，新烟碱类杀虫剂通常被用作叶面杀虫剂，以控制刺吸式害虫，如玷污叶甲（TPB，Lygus lineolaris）。在这项研究中，进行了喷雾生物测定，以确定五种新烟碱类杀虫剂和噻虫砜对来自密西西比三角洲地区的敏感和秋季后期田间采集的 TPB 成虫的毒性。与敏感种群相比，田间采集的 TPB 对吡虫啉的抗性最高（高达 19.5 倍），对乙酰甲胺磷的抗性中等（9.43 倍），对噻虫啉（13.68 倍）、噻虫嗪（7.88 倍）的抗性最低，对噻虫砜（1.82 倍）的抗性最低。增效剂研究表明，增效醚（PBO）分别显著增加吡虫啉和噻虫嗪的毒性 22.2 倍和 15.3 倍，而三苯基磷酸盐（TPP）和马来酸二乙酯（DEM）仅对两种新烟碱类杀虫剂表现出 2-3 倍的增效作用。在田间采集的 TPB 中，与敏感种群相比，酯酶、谷胱甘肽 S-转移酶（GST）和细胞色素 P450 单加氧酶（P450）三种解毒酶的活性分别显著增加了 3.43 倍、1.48 倍和 2.70 倍。此外，在暴露于吡虫啉或噻虫嗪 48 小时后，抗性 TPB 成虫表现出酯酶活性升高、GST 活性降低，而 P450 活性没有显著变化。进一步的研究表明，某些酯酶和 P450 解毒基因的表达在抗性 TPB 中显著升高。总的来说，这些结果表明，酯酶和 P450s 的表达和酶活性的升高是 TPB 对新烟碱类杀虫剂代谢抗性的关键机制。我们的研究结果还为选择和采用新烟碱类杀虫剂来管理 TPB 的抗性以及最大限度地减少觅食蜜蜂的毒性风险提供了有价值的信息。
