Control of fall armyworm in corn using foliar applications of entomopathogenic nematodes

Carlos Esquivel
Luis A. Canas

The use of entomopathogenic nematodes for the control of below-ground insects has shown historically positive outcomes. Application of nematodes to the foliage for the control of above-ground insects are expected to be less effective; however, above-ground pest control with nematodes remains seldom studied. Therefore, this study aims to enhance our understanding of foliar pest control with nematodes, by using two commercially available entomopathogenic nematodes, Heterorhabditis bacteriophora and Steinernema carpocapsae, for the control of fall armyworm (FAW), one of the most important above-ground pests of corn. Thus, we performed foliar applications of nematodes in corn fields infested with FAW larvae at the Biological Control Research Station of the Zamorano University, Honduras. Our first goal was to understand which nematode and dose provide better FAW control; FAW was compared to the insecticide emamectin benzoate, the commercial standard for FAW chemical control in Honduras. 
The second goal of our study was to understand how long a foliar application of nematodes provides control of FAW (named hereafter nematode residuality). We hypothesized that foliar applications of nematodes would provide similar FAW control as the insecticide emamectin benzoate, but their control residuality declines within hours after application. We found evidence that foliar application of nematodes could be a promising tool for FAW management.