Toxicity and repellency of different insecticides to Odontotermes obesus (Rambur, 1842) (Blattodea: Termitidae: Macrotermitinae)

Abstract

Fungus-growing termites are important pests for buildings and agriculture in Asia and Africa. This study assessed four insecticides (fipronil 5% SC, imidacloprid 20 SL, thiamethoxam 25 WG and chlorfenapyr 360 SC) for their toxicity and repellency to the fungus-growing termite, Odontotermes obesus (Rambur, 1842) (Blattodea: Termitidae: Macrotermitinae). The study was conducted at Ghazi University, Dera Ghazi Khan, Pakistan from September-October, 2016 and was undertaken to identify effective termiticides along with their optimal concentrations for future use in baits and localized treatments. The chemicals assessed were differed significantly in their toxicity. Chlorfenapyr and thiamethoxam were more toxic and faster acting with lower LC 50 and LT 50 values than imidacloprid and fipronil. The four chemicals were statistically similar at each concentration. Odontotermes obesus was not repelled by 0-20 mg/l chlorfenapyr, 0-40 mg/l fipronil, 0-80 mg/l imidacloprid or 0-20 mg/l thiamethoxam. These results suggest that chlorfenapyr, imidacloprid and thiamethoxam may be used as soil termiticides, whereas fipronil can be used both as soil termiticide and in termite baiting programs.