Biology of fall armyworm, Spodoptera frugiperda (J.E. Smith) on maize (Zea mays L.)

Abstract

The biology of fall armyworm, Spodoptera frugiperda (J.E. Smith) was studied during July-December, 2019 under laboratory conditions at 26 ± 2°C temperature and 75 ± 5% relative humidity. The freshly laid eggs from nucleus culture were taken to study the biology of fall armyworm. After hatching, newly emerged 40 larvae were individually reared on fresh small bits of maize leaves, these leaves were changed daily as food. After the completion of larval period, the pupae were transferred gently into egg laying chambers for the emergence of the adults. In each chamber, pair of male and female adults was released and chambers were provided with 10% honey solution soaked cotton wicks placed separately in small petri plates. The female was observed laying eggs with the average fecundity of 1082 eggs. The incubation, total larval (I to VI instar), pupal, pre oviposition, oviposition and post ovipositon period were recorded to be from 2-3, 13-20, 8-12, 3-4, 2-3 and 4-5 days, respectively. The male and female longevity were 7-10 and 10-12 days, respectively. The total life cycle of male and female was observed to be 32-44 and 35-47 days, respectively. The sex ratio of male to female was 1:1.30.