Impact of host plants on biological characteristics and Vg/VgR expression of Spodoptera frugiperda

Spodoptera frugiperda (J. E. Smith) is a worldwide migratory invasive and polyphagous pest. S. frugiperda posed a severe threat to food security and agricultural production. In this study, we examined the biological parameters of S. frugiperda on five host plants: maize, wheat, rice, honeysuckle, and Chinese yam. Furthermore, the effect of different host plants on SfVg/SfVgR expression was investigated, and then, the correlations between SfVg/SfVgR expression and key population proliferation parameters of S. frugiperda were clarified. The results showed that the larval stage of S. frugiperda was shortest on wheat, and longest on Chinese yam. Pupal weight was highest on honeysuckle and lowest on rice. Fecundity on honeysuckle, maize, and wheat was significantly higher than that on rice and Chinese yam. The SfVg/SfVgR expression levels of S. frugiperda fed on honeysuckle, maize, and wheat were also significantly higher than that on rice and Chinese yam. Meanwhile, significant linear regression correlations existed between SfVg/SfVgR expression level with key parameters (pupal weight and oviposition number per female) of S. frugiperda. Our results confirmed that S. frugiperda had a potentially harmful risk to two Chinese herbs (honeysuckle and Chinese yam). The expression level of Vg/VgR could be used as a molecular marker of S. frugiperda reproductive potential and forecasting the outbreak potential of S. frugiperda on different host plants. This study provided the foundation for further assessment of S. frugiperda risk to crops in China and formulating management strategies.