Seasonal variation in insecticide resistance in Spodoptera litura Fab. (Lepidoptera: Noctuidae) to different insecticides

The study was carried out to know the seasonal variation in resistance of field strain of Spodoptera litura to four insecticides belonging to different groups over a period of twelve months by conducting bioassays at regular intervals. The Bangalore field population showed higher levels of resistance to most of the insecticides during April month coinciding with summer season and the lowest during December month coinciding with winter season. Contrarily, the pest exhibited relatively higher resistance to methomyl during August month compared to April and December months.