38th Annual Meeting of the Society for Invertebrate Pathology

The Cañete Valley in the subtropical Coastal Region of Central Perú is the most important area for sweet potato production. In the past few years, white grubs (Bothynus maimon and Anomala spp.) have become key pests of this crop. The larvae cause serious damage to the roots and adversely affect the quality, value and export possibilities of sweet potato. We conducted a survey for natural enemies of the white grubs and report the first isolation of an entomopathogenic nematode, a Heterorhabditis species, from the Peruvian Coastal Region. The nematode was isolated from larvae of B. maimon in corn and sweet potato fields in Cañete Valley at an altitude of 90 m. The LC₅₀ of this nematode against white grub larvae (third instar Anomala sp.) in the laboratory was124 infective juveniles/larva, and a rate of 50 infective juveniles/cm² caused 68% larval mortality in pot tests in the screen house. This nematode species was also efficacious against other pest insects including the sweet potato weevil (Euscepes postfasciatus) and two species of potato tuber moths (Phthorimaea operculella and Symmetrischema tangolias).