College of Agricultural and Environmental Sciences, Griffin Campus, University of Georgia, Griffin, GA 30223, USA.
J Econ Entomol. 2009 Dec;102(6):2279-88. doi: 10.1603/029.102.0633.
Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae). Mobility impairment and lethal times were determined after topical treatments. Ants were immobilized most quickly by bifenthrin, followed by chlorfenapyr and thiamethoxam. After 2 h, the number of fipronil-treated ants unable to walk out of test arenas did not differ from control ants. Median lethal time (LT50) after topical treatment was lowest in the bifenthrin treatment, followed by thiamethoxam, chlorfenapyr, and then fipronil. Mortality due to horizontal exposure was evaluated at 10, 20, or 30 degrees C, with topically treated ant corpses serving as donors. There was low to moderate horizontal activity in bifenthrin and chlorfenapyr treatments, with no temperature effect in bifenthrin treatments and a positive temperature effect in chlorfenapyr treatments. Mortality in the fipronil treatments was highest and was positively correlated with temperature. Thiamethoxam treatments did not differ from controls at 10 degrees C, but mortality increased with temperature. To evaluate contact activity, either all of 20% of the ants in a cohort were exposed to insecticide-treated pine needles. In both tests, mortality was highest in fipronil and bifenthrin treatments, followed by thiamethoxam, with lowest mortality in chlorfenapyr treatments. Effectiveness as a barrier was evaluated by providing a choice between bridges treated with insecticide or water. Although bifenthrin did not provide an impenetrable barrier, it was the only treatment having fewer ants than its paired control. Mortality data suggest that lack of recruitment rather than repellency account for this result.
溴氰菊酯、氯氟氰菊酯、氟虫腈和噻虫嗪对阿根廷蚁（Linepithema humile）（膜翅目：蚁科）的活性进行了评估。在局部处理后确定了运动障碍和致死时间。双氟苯菊酯使蚂蚁最快失去活动能力，其次是氯氟氰菊酯和噻虫嗪。2 小时后，无法走出试验场的氟虫腈处理的蚂蚁数量与对照蚂蚁没有差异。局部处理后，致死时间（LT50）最短的是双氟苯菊酯，其次是噻虫嗪、氯氟氰菊酯，然后是氟虫腈。在 10、20 或 30°C 下评估了水平暴露引起的死亡率，用局部处理过的蚂蚁尸体作为供体。双氟苯菊酯和氯氟氰菊酯处理中水平活动低至中等，双氟苯菊酯处理中温度无影响，氯氟氰菊酯处理中温度呈正相关。氟虫腈处理中的死亡率最高，且与温度呈正相关。噻虫嗪处理在 10°C 时与对照无差异，但死亡率随温度升高而增加。为了评估接触活性，要么将一个群体中 20%的蚂蚁全部暴露于用杀虫剂处理过的松针上，要么暴露于其中的 20%。在这两种测试中，死亡率最高的是氟虫腈和双氟苯菊酯处理，其次是噻虫嗪，而氯氟氰菊酯处理的死亡率最低。通过在带杀虫剂或水的桥之间提供选择来评估作为屏障的有效性。虽然双氟苯菊酯不能提供不可穿透的屏障，但它是唯一一种比配对对照的蚂蚁数量少的处理方法。死亡率数据表明，这种结果是由于缺乏招募而不是排斥造成的。
