Surface treatment is commonly used in controlling the red imported fire ants, Solenopsis invicta Buren. In the present study, the behavioral responses of S. invicta workers to surfaces treated with insecticides were investigated. Toxicological tests showed that beta-cypermethrin had the highest contact toxicity (with the lowest LC₅₀ value) among nine tested insecticides, followed by thiamethoxam, fipronil, indoxacarb, chlorfenapyr, spinetoram, rotenone, avermectin, and chlorantraniliprole. In the laboratory, surfaces treated with beta-cypermethrin or rotenone significantly reduced the number of foraging ants. In addition, S. invicta workers transported significantly more particles (measured in weight and/or covered area) onto surfaces treated with fipronil (50, 500, and 5000 µg/mL), rotenone (5000 µg/mL), or avermectin (5000 µg/mL) compared with the controls. Similarly, these insecticides significantly triggered the particle-covering behavior of ants in the field. We hypothesized that such behaviors would reduce the contact toxicity of insecticides against S. invicta. When the surfaces treated with fipronil or rotenone (500 or 5000 µg/mL) were artificiality covered with particles, S. invicta had significantly higher LT₅₀ values compared with insecticide-treated surfaces without particles. This study provides the first evidence that S. invicta workers can perform particle-covering behavior to reduce the toxicity of certain insecticides, which constitutes a unique insecticide-resistance strategy in ants.

表面处理常用于防治红火蚁、Solenopsis invicta Buren。在本研究中，调查了S. invicta工人对用杀虫剂处理的表面的行为反应。毒理学试验表明，在九种受试杀虫剂中，β-氯氰菊酯的接触毒性最高（LC ₅₀值最低），其次是噻虫嗪、氟虫腈、茚虫威、氯芬吡、多杀菌素、鱼藤酮、阿维菌素和氯虫苯甲酰胺。在实验室中，用 β-氯氰菊酯或鱼藤酮处理的表面显着减少了觅食蚂蚁的数量。此外，S. invicta与使用氟虫腈（50、500 和 5000 µg/mL）、鱼藤酮（5000 µg/mL）或阿维菌素（5000 µg/mL）处理的表面相比，工人将更多的颗粒（以重量和/或覆盖面积测量）控件。同样，这些杀虫剂显着触发了田间蚂蚁的颗粒覆盖行为。我们假设这种行为会降低杀虫剂对S. invicta 的接触毒性。当用氟虫腈或鱼藤酮（500 或 5000 µg/mL）处理的表面被人工颗粒覆盖时，与没有颗粒的杀虫剂处理的表面相比， S. invicta具有显着更高的 LT _50值。这项研究提供了第一个证据表明S. invicta工作人员可以进行颗粒覆盖行为以降低某些杀虫剂的毒性，这构成了蚂蚁独特的抗杀虫剂策略。