Comparative toxicity of selected new-chemistry insecticides against subterranean termites odontotermes obesus ramb. (Isoptera: Termitidae)

Abstract

Subterranean termites cause considerable damage to a wide number of agricultural crops, tree plantations and wooden infrastructures all over the world including Pakistan. This study was aimed to evaluate the comparative efficacy of 10 commercial formulations of new-chemistry insecticides against Odontotermes obesus (Isoptera: Termitidae), one of the most economic subterranean termite species in Indo-Pak region. Label-recommended dose rates of insecticides were tested against worker termites using modified filter paper disc method according to completely randomized design. All insecticides caused significant mortality of termites as compared to control treatment. Formulations of chlorantraniliprole, chlorfenapyr and pyriproxyfen exhibited maximum termite mortality, ranging from 31.18±5.67, 28.33±7.03 and 21.67±4.01%, respectively at 3 h post-exposure to 100% at 24 h, followed by triflumuron (81.67±3.07%) and indoxacarb (63.33±5.58%). Moreover, chlorantraniliprole, chlorfenapyr, pyriproxyfen, emamectin, indoxacarb and triflumuron showed LT 50 values of 15.62 h (10.66 - 20.58), 18.48 h (14.72 - 22.93), 27.34 h (22.34 - 33.97), 28.22 h (23.37 - 34.53), 31.91 h (26.68 - 38.90) and 32.82 h (28.03 - 39.11), respectively. On the contrary, spirotetramat, pymetrozine and spinosad were least effective against O. obesus termites. Conclusively, based on the results of this study, chlorantraniliprole, chlorfenapyr, pyriproxyfen, triflumuron and indoxacarb are recommended to be incorporated in future integrated pest management programs against subterranean termites.