Assessment of predatory activity in residential lawns and sod farms

Abstract

The occurrence and abundance of predatory fauna in turfgrass systems have been reported; however, the activity of predators has rarely been described. The fall armyworm Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) is a major pest of turfgrass in the United States for which arthropod predation is not considered a key pest management option, but the role of predation on S. frugiperda has not been assessed in turfgrass systems, which are managed at varying intensities. Thus, the objective of this study was to determine (1) the incidence and (2) the severity of predation in less intensively managed residential lawns and intensively managed sod farms. The percentage of predation on live S. frugiperda sentinel larvae and the percentage of predation and its severity on clay models were significantly greater in the residential lawns than in the sod farms. Among the seven impression types recorded on clay models, paired marks were the most abundant. Four new impression types, deep cut marks, stacked surface marks, scooped marks, and U-shaped marks, were observed on clay models in both turfgrass systems. Formicids were documented at significantly greater densities than were other predatory groups, such as carabids. Thus, the results show the need for enhanced predatory activity in sod farms by developing integrated pest management strategies and adopting measures to conserve natural enemies.