Susceptibility of Various Developmental Stages of the Fall Armyworm, Spodoptera frugiperda, to Entomopathogenic Nematodes

Simple Summary The fall armyworm, Spodoptera frugiperda, native to Central and South America, has recently invaded Africa and Asia, causing serious economic damage to various crops. The chemical control of fall armyworm is not effective due to the development of pesticide resistance as well as environmental contamination. Alternatively, biological control using natural enemies can be used successfully in a sustainable way. Entomopathogenic nematodes are soil-dwelling natural enemies for many underground pest insects including lepidopteran caterpillars. This study evaluates the virulence of several entomopathogenic nematodes on different developmental stages of fall armyworm. We found that all the larval and pupal stages of fall armyworm were highly susceptible to the entomopathogenic nematodes. Our study provides important information of entomopathogenic nematodes for the practical application of biological control of fall armyworm. The fall armyworm, Spodoptera frugiperda, which is native to Central and South America, has recently invaded Africa and Asia, causing serious damage to various crops. Although management to date has been largely unsuccessful, entomopathogenic nematodes (EPNs) are a potential biological control agent that could be used to control the late larval and pupal stages of S. frugiperda that dwell under the ground. Here, we compared the virulence of seven EPNs against larval and pupal stages of S. frugiperda. In a Petri dish assay, both Heterorhabditis indica and Steinernema carpocapsae were highly virulent against younger larvae, whereas S. arenarium and S. longicaudum were highly virulent against older larvae. In contrast, H. bacteriophora, Heterorhabditis sp., and S. kushidai showed low virulence against all larval stages. In soil column and pot assays, H. indica, S. carpocapsae, and S. longicaudum were highly virulent against late larval and pupal stages compared with the other EPN species. Thus, H. indica, S. carpocapsae, and S. longicaudum are recommended for the biological control of S. frugiperda. Our study provides important information of EPNs for the practical application of biological control of fall armyworm.