Effects of sublethal concentrations of ivermectin on behaviors of Coptotermes formosanus (Isoptera: Rhinotermitidae)

Coptotermes formosanus Shiraki is an important pest, damaging buildings, houses and trees. Chemical control is the main measure for reducing the infestation of C. formosanus at present. Ivermectin is one of avermectin's derivatives and has high toxicity on Reticulitermes flaviceps. Effects of sublethal concentration of ivermectin on the feeding, tunneling, and fighting in C. formosanus was evaluated in this study. The results showed that sublethal concentration of ivermectin would decrease the food consumption, tunneling and fighting capacity of C. formosanus workers. Workers exposed to filter paper with 15.0 and 30.0 mg/L ivermectin for 24 hours had significantly less food consumption and shorter tunneling length compared with the control workers and workers exposed to 1.0 mg/L ivermectin for 72 hours exhibited significantly weaker aggressive behavior than the control workers in a C formosanus population.