The Integrated Pest Management (IPM) Programme under development at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) calls for a proper monitoring system. Experiments conducted in groundnut fields at ICRISAT Center near Hyderabad, in peninsular India, to establish the optimum height for pheromone traps to monitor Spodoptera lituta (F), indicated that the male flight pattern changes considerably during the cropping period. During the seedling stage (sowing to 6 weeks), most moths were caught at 0.5 and 1.0 m. In the initial growth phase (7–11 weeks), the traps at 4.0 m caught most moths. During the optimum growth phase (12th week to harvest) of the crop the traps at 1.0 m height trapped most moths. After harvest, the traps at 4.0 m again recorded the highest catch. These data are interpreted in terms of the migration pattern of S. litura moths during the crop season. We suggest monitoring this species, using 1 m height traps.
Males were found to be more active around 0300 hr, with a small peak after sunset (2000 hr). Irrespective of season, the peak flight activity of this species was around 0300 hr in groundnut fields.