New Strains of the Entomopathogenic Nematodes , , and for White Grub Management.

White grubs possess natural defense mechanisms against entomopathogenic nematodes (EPNs). Hence, EPN isolates that naturally infect white grubs tend to be among the most effective biological control agents of white grubs. We tested the virulence of four EPN isolates recently isolated from infected white grubs in turfgrass areas in central New Jersey, USA against third-instar larvae of , , and , which are pests of turfgrass and ornamental plants in the northeastern USA. Against and larvae, the Ad and SL isolates were highly virulent in laboratory tests, whereas HF was less virulent and SH the least virulent. None of the isolates caused high mortality of larvae. EPN efficacy in greenhouse tests against followed the same pattern. The original isolate of , the AMK001 strain, that had been maintained in the laboratory on and larvae for 19 years showed the same virulence level against larvae as it did soon after its first isolation and was also as virulent as the fresh Ad isolate; both isolates were more virulent than SL. Future tests should determine the ability of these white grub-adapted isolates to provide long-term suppression of white grub populations.