Biology and nutritional indices of the fall armyworm Spodoptera frugiperda fed on five Egyptian host plants as a new invasive insect pest in Egypt

In this study, the effect of five host plants on the biology and food consumption of the fall armyworm Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) was evaluated in Egypt. Developmental periods and weight of different growth stages, percentages of pupation and adult emergence, survival, and nutritional indices were evaluated on maize, castor oil, clover, broad bean, and lettuce. The results showed that the developmental period of S. frugiperda was significantly longer on the broad bean. The pupation percentage of S. frugiperda was significantly affected by the host plant. In contrast, the adult emergence was not significantly different on host plants. Our result also showed maximum weights in food consumption, and frass occurred in the larvae fed on lettuce. While the lowest weights for consumption were observed in larvae on maize and broad bean resulting in minimum frass weights. The highest percentage of approximate digestibility (AD) of the larvae was on broad bean and clover, and the lowest AD was by larvae fed on maize. The highest percentages of conversion of ingested food (ECI) and conversion of digested food (ECD) were observed for larvae fed on maize leaves. The lowest values of ECI and ECD were observed on larvae fed on broad bean leaves. Based on the results, it seems that lettuce, castor, and maize were preferred for S. frugiperda.

Keywords:

fall armyworm , maize leaves , host plants , life history , food utilization