Entomopathogenic nematode performance against Popillia japonica (Coleoptera: Scarabaeidae) in school athletic turf: Effects of traffic and soil properties

Abstract

Entomopathogenic nematodes (EPNs) have potential as an alternate means of controlling soil-dwelling pests in settings such as school athletic fields, where use of chemical pesticides is often restricted or prohibited. Athletic fields are also unique among turfgrass systems, as their distinct pattern of foot traffic can result in compaction and other soil properties varying across different areas of the field, potentially causing variability in EPN performance even within a single field, as many abiotic and biotic soil properties are known to influence EPN efficacy. We tested the efficacy of the EPNs Steinernema feltiae and Heterorhabditis bacteriophora against third-instar grubs of the Japanese beetle Popillia japonica in high-traffic and low-traffic areas of two soccer fields in New York State, one grown atop loam soil and the other atop loamy sand. Efficacy was low in the loam soil but modest for both species in the loamy sand, though the only significant increase over controls occurred in S. feltiae-inoculated plots within low traffic areas in 2016. Non-metric multidimensional scaling revealed positive associations between efficacy of both EPN species and soil sand content, suggesting that sandy soils are most optimal for curative applications against turfgrass pests. Soil biotic factors, such as microarthropod abundance, were not found to have an effect on EPNs. These results will aid turfgrass managers by improving knowledge of the conditions required for effective use of EPNs.