Inoculative release of Heterorhabditis bacteriophora Poinar (Oswego) and Steinernema feltiae Filipjev (NY04) mixture can enhance biological control of soil-dwelling pests in turfgrass production systems

Abstract

ABSTRACTIn this study, the utility of inoculative releases of local strains of Heterorhabditis bacteriophora and Steinernema feltiae isolated from northern New York (NY) State for managing soil-dwelling pests in sod (turfgrass production systems) was evaluated. The objectives of the project were to (a) quantify changes in biocontrol potential during the sod production process and (b) evaluate the potential for the nematodes to suppress populations of soil-dwelling turf pests following harvest and installation at a new site. A field study was conducted on four sod fields in central NY State on soils with varying texture and organic matter content, and a post-harvest sod installation study was performed in the greenhouse on a sandy loam soil. Nematode-induced mortality of Galleria mellonella was increased significantly one month following inoculation but differed between fields with different soil types, likely due to variation in soil organic matter content. In the following year, nematode persistence in sod fields was low, likely driven by moderate to severe drought conditions. In contrast, upon harvest and installation, significant nematode-induced mortality was observed in soil receiving an installation of muck-produced sod. Enhanced nematode-induced mortality was detected in both the greater wax moth and third instar Japanese beetle larvae. This study indicates that inoculation of sod with entomopathogenic nematodes can improve biocontrol potential during sod production and after harvest, however, the utility of this practice is sensitive to soil conditions, and likely most efficacious on coarse-textured soils with high organic matter.