Efficacy of entomopathogenic fungi and Heterorhabditis bacteriophora against masked chafer, (Coleoptera: Scarabaeidae), white grubs

Masked chafer grubs, Cyclocephala spp., are the most widespread and destructive turf pests in VA. Although conventional insecticides are still the main approach for white grub control, their impact on the environment, natural enemies, and the problem of insecticide resistance, have increased public awareness for a more bio-rational approach to managing white grubs. Entomopathogenic nematodes, e.g. Heterorhabditis bacteriophora, and several entomopathogenic fungi, such as Beauveria bassiana and Metarhizium anisopliae, appear to be good alternatives to conventional insecticides. Due to environmental limitations, however, their efficacies vary significantly if used alone, while additive or synergistic effects might be achieved from the application of more than one biological control agent. In this experiment, we evaluated the interaction between H. bacteriophora and B. bassiana / M. anisopliae for causing mortality in masked chafer grubs at various larval stages as well as their sub-lethal effects on white grub fitness.