EFFECT OF HOST PLANTS ON THE BIOLOGY AND DIGESTIVE PHYSIOLOGY OF Spodoptera frugiperda

Fall armyworm (Spodoptera frugiperda), a highly polyphagous lepidopteran pest, is impacting millions of hectares of maize crops and thereby posing a major threat to food security. Yet, up till present, limited research has been conducted on the biological determinants and digestive enzymes of S. frugiperda fed on different plants. Our results showed that there were differences in developmental duration, and body and pupal weight by statistical data. Individuals from F1 and F3 generations fed on Zea mays had the shortest development period, and the 10d weight (0.173mg, 0.177mg) and pupa weight (0.171mg, 0.193mg) were the heaviest, while the 10d weight (0.046mg, 0.054mg) and pupa weight (0.108mg, 0.138mg) were the lightest in those fed on Eleusin indica and Triticum aestivum, respectively. There were also significant differences in the digestive enzyme activities of S. frugiperda fed on four host plants. The ttypsin activity, a-amylase activity, and lipase activity were the highest in F1 larvae fed on Z. mays. In F3 generation, ttypsin activity had a high level in Z. mays, which was 856.26 folds higher than that in Triticum aestivum, which indicate digestive enzymes play key roles in helping S. frugiperda to adapt to the host plants. These findings provided a foundation for further understanding the role of digestive enzyme in S. frugiperda larvae in response to host plants.