Northern corn rootworm beetle densities near a red-winged blackbird roost

Abstract

Population estimates of northern corn rootworm beetles (Diabrotica longicornis (Say), Chrysomelidae; Coleoptera) increased linearly away from a red-winged blackbird (Agelaius phoeniceus (L.), Emberizidae; Passeriformes) roost located at Montezuma National Wildlife Refuge, Cayuga County, New York, U.S.A. Red-winged blackbirds foraging in cornfields near this roost commonly consumed rootworm beetles, indicating that this predation could have been responsible for the lower rootworm beetle populations in this area. However, even if the reduced beetle numbers near the red-winged blackbird roost were the result of predation by this bird, this benefit compensated for only approximately 4% of the damage the birds inflicted to standing corn.