Comparative Assessment of Different Rearing Diets on the Developmental and Reproductive Behaviour of Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae).

Abstract

Many agricultural crops are attacked by polyphagous insect pest known as the fall armyworm, Spodoptera frugiperda (J.E. Smith) in India. Information regarding the developmental and reproductive behaviour of S. frugiperda on various rearing diets is vital for mass production in the laboratory. The present study reports larval, pupal, and adult development period, survival rate, parameters of life table, and nutritional indices of S. frugiperda on maize-artificial diet (maize up to 3rd instar and artificial diet after), artificial diet, maize leaves, and castor leaves under laboratory conditions. Egg to adult preoviposition development time on maize-artificial diet (27.78 ± 0.31 days) was significantly lower than that on other diets. Furthermore, S. frugiperda fecundity on maize-artificial diet was significantly higher than on artificial diet, maize leaves, and castor leaves. The values of finite rate of increase (λ) and intrinsic rate of increase (r) were highest on the maize-artificial diet at 0.176 day^-1 and 1.193 day^-1, respectively, as compared to others. The values of nutritional indices such as relative growth rate (RGR) and relative consumption rate (RCR) were substantially superior for S. frugiperda fed on maize-artificial diet, artificial diet, and maize leaves than for larvae fed on castor leaves. Growth and reproduction parameters values showed that S. frugiperda larvae rearing on successive feeding on maize-artificial diet were the most suitable. The present study concludes that maize-artificial diet-based successive feeding can be used as mass multiplication of S. frugiperda in laboratory conditions.