On factors causing outbreak of Spodoptera litura (Fabricius)

Abstract

The population dynamics and fluctuation of Spodoptera litura (Fabricius) were studied using sex pheromone trap and net cover, the reasons for outbreak of the pest in recent 10 years were searched. The authors believe that the increasing area of some economically important crops (mainly vegetable) and protected cultivation provide the suitable sites for feeding and overwinter of S.litura.The pest tends to occur earlier than before, which is helpful to buildup of big population by increasing in the original amount and generations in field. Other reasons for the pest outbreak may include high temperature and less rainfall in summer, and misuse of pesticides that might kill many natural enemies of this pest.