author(s)
Avinash TG and Kumar NG

abstract
Bioassay studies were carried out to test the lethal time response of clothianidin, fipronil and bifenthrin under laboratory conditions. Insecticide clothiadin at the concentrations of 0.025, 0.05, 0.075 and 0.1%, fironil and bifenthrin were evaluated at the concentration of 0.075 and 0.05%, respectively. Results revealed that Odontotermes sp. worker termites were relatively more susceptible to the insecticides after one month of treatment application. The LT₅₀ values for different insecticides increased as the time after the treatment increased. The lowest LT₅₀ of 3.69 h was obtained during one month after treatment in bifenthrin @ 0.05% treated soil and highest LT₅₀ of 33.19 h was obtained in the clothianidin @ 0.025% during ten months after treatment of soil. In all the subsequent months bifenthrin was found highly toxic to Odontotermes sp. worker termites except five and nine months in which clothianidin @ 0.1% recorded the least LT₅₀ value of 7.90 and 16.11 h, respectively.