Variation in the laboratory susceptibility of four species of turf-infesting white grubs (Coleoptera: Scarabaeidae) to a series of biorational, biological and chemical control products

White grubs are the most widespread and damaging pests in turfgrass habitats of the Northeast U.S., and their management is highly dependent on chemical pesticides. Because this complex includes eight species, opportunities for pest management in this system would be enhanced by understanding how susceptibility to control products varies across taxa. We tested seven biologicals, five biopesticides and seven chemical insecticides against third instar Asiatic garden beetle, European chafer, Japanese beetle and Oriental beetle under laboratory conditions. Across species, the most efficacious biological and chemical insecticide alternatives were Steinernema scarabaei and chlorpyrifos, respectively. Biorationals were highly variable across species. For biorationals and chemicals insecticides, European chafer was the least susceptible species. For biologicals, Japanese beetle was the least susceptible species. Considering all control products, the most susceptible species was Oriental beetle. The magnitude of variation in susceptibility across species supports the idea that a single product will not reliably suppress populations of all taxa, and highlights the need for pest management practitioners to diagnose and differentiate species before intervention.