Entomopathogenic nematodes for control of Phyllophaga georgiana (Coleoptera: Scarabaeidae) in cranberries

A series of laboratory and greenhouse experiments evaluated the entomopathogenic nematodes Steinernema scarabaei Stock & Koppenhöfer, Heterorhabditis bacteriophora Poinar, and H. zealandica Poinar for control of secondand thirdinstar cranberry white grub, Phyllophaga georgiana Horn (Coleoptera: Scarabaeidae), in cranberries. Steinernema scarabaei was the most effective species with 76 100% control at a rate of 2.5 10 IJ/ha in the greenhouse experiments. H. zealandica and especially H. bacteriophora were generally less effective and required rates of 5 10 IJ/ha for acceptable control. Larval stage had no effect on H. zealandica and H. bacteriophora performance, whereas S. scarabaei was more effective against third instars than second instars in the laboratory but not in the greenhouse experiments. Steinernema scarabaei, should it become commercially available, could be an effective alternative to chemical insecticides for P. georgiana management.