First report of Ovomermis sinensis (Nematoda: Mermithidae) parasitizing fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) in China

Spodoptera frugiperda invaded China in the end of 2018 and has caused severe damage to maize and other crops. Several S. frugiperda naturally parasitized by nematodes were observed in Hainan Province, China. The morphological characteristics based on the results of scanning electron microscopy indicated that the nematode belongs to the family Mermithidae. Additionally, coding sequences for the 18 S and 28 S rDNA were amplified from the nematode genome, and phylogenetic analysis revealed that the nematode belongs to Ovomermis sinensis, a known entomoparasitic nematode. Our finding is the first record that S. frugiperda was naturally parasitized by O. sinensis. The results of this study are of great significance for potential biological control of S. frugiperda by indigenous natural beneficial organisms, i.e. O. sinensis within an integrated pest management system.