Occurance, taxonomic identification and life cycle of fall armyworm; Spodoptera frugiperda (J.E. Smith) in Sri Lanka

Fall armyworm (Spodoptera frugiperda J.E. Smith) is an alien, invasive voracious pest attacking mainly maize crop and about 80 other plant species. It is native to the tropical regions of the western hemisphere from the United States to Argentina. Recent occurrence of this pest was reported in African continent and in India in years 2016 and 2018, respectively. The first reporting of fall armyworm in Sri Lanka was in October, 2018 from Iddapola, Mahaoya in Ampara district though it was first reported as an unknown pest damage. Samples were collected and the pest were reared in the laboratory in insect cages till the adult stage and based on morphological features it was suspected to be armyworm. Mated adults were transferred to new insect cages and the second generation adults and sixth instar larvae were identified based on taxonomic features and confirmed as fall armyworm, S. fruigiperda. The life cycle study indicated that the incubation period of eggs ranged 2-3 days, the larval period 14-19 days and the pupal period between 9 -12 days. Thus, the total life cycle of male and female fall armyworm reported in Sri Lanka is 32-43 days and 34-46 days, respectively.