Improved bioassay method for evaluation of oviposition deterrents against Old World bollworm, Helicoverpa armigera (Hübner)

Abstract

Old world bollworm Helicoverpa armigera (Hübner) is one of the serious pests of agricultural crops with more than 184 recorded hosts including cotton. In cotton, H. armigera usually causes yield losses up to 40% with 20-80% damage intensity. In the Indian context it has already developed resistance to most conventional classes of insecticide and its survival on Bt cotton also has been reported in some isolated places. Under such situation, application of semiochemicals can serve as an alternative management option. Among the semiochemicals, oviposition deterrent ones are known to be the most effective as they minimize the infestation at first line of attack by deterring the female moths and protecting the host from oviposition. However, before applying at field level, it is important to develop and standardize a bioassay method for evaluation of oviposition deterrent compounds under laboratory condition. Here, we report a suitable improved bioassay method for evaluation of effect of oviposition deterrents against H. armigera. The five days duration of bioassay method was finalized according to the peak activity of adult moth in terms of mating and fecundity. This investigation presents a method, for finding promising oviposition deterrent compound which will be helpful for researchers to identify the most potent molecule/compounds against H. armigera