Toxicity and Transmission of Thiamethoxam in the Asian Subterranean Termite Coptotermes gestroi (Isoptera: Rhinotermitidae)

摘要

The toxicity and horizontal transmission of thiamethoxam was evaluated in the workers of the Asian subterranean termite Coptotermes gestroi Wasmann (Isoptera: Rhinotermitidae). Brief exposure to sand treated with thiamethoxam at concentration ranging from 0.25 to 50?μg/ml resulted in a dose-dependent mortality in C. gestroi. Sand treated with 50?μg/ml thiamethoxam resulted in very high mortality within 30–60?min of exposure. Termites exposed to sand treated with 0.25–25?μg/ml exhibited delayed toxicity and nonrepellency in C. gestroi. A horizontal transmission study using 25?μg/ml of thiamethoxam at donor–recipient ratio of at least 2:5 (treated:untreated) indicated that thiamethoxam can be transferred between exposed and unexposed workers, resulting in significant termite mortality in unexposed termites within 1–3 d post exposure.