Feasibility of Timing Insecticide Applications based on Pheromone Trap Catches of Fall Armyworm, Spodoptera frugiperda (J.E. Smith) in Maize

Abstract

The fall armyworm, Spodoptera frugiperda (J.E. Smith), an invasive pest has recently spread to all over India and several other countries. For management of this pest, it is important to monitor moth activity by using pheromone traps. In the present study pheromone traps (Polythene sleeve type) baited with ‘GAIAGEN Lures’ (rubber septa) were installed @ 12 traps/ha in the experimental fields. The adult male moths caught during an observational week were counted. Per cent plant infestation was recorded at every seven days interval. The results have revealed that there was a gap of several weeks between peak field infestation and peak moth catch/trap, it indicates that field infestation was high even though moth trap catch was low and there is a negative association between the trap catches and per cent plant infestation. The relationship between field infestation (No. of larvae/plant and % plant infestation) and trap catches were negatively correlated for all the five weeks i.e., nth, (n-1)th, (n-2)th, (n-3)th, (n-4)th  in both 2022-23 and 2023-24 years. There was no concrete evidence of field infestation taking place after adult trap catches. Therefore, it can be concluded that only pheromone trap catch data cannot be taken into consideration for timing insecticide application. Field scouting could be better option for monitoring fall armyworm in maize.