Larvae/White Grubs in Lawn

Biology and Life Cycle—one-year complete life cycle from egg, larva, pupa, adult. Adults usually emerge in June, females begin begin egg laying immediately and in to September. Each female lays up to 60 eggs as an adult (not all at once) in nearby grass turf, they seek well-irrigated areas. Cool-season grasses like Kentucky blue grass, ryegrass and fescue are their preferred turf for egg laying. White Grubs live in turf roots – fall, winter, spring, emerging as adults in June for the cycle to begin again.

The best window to apply lawn products to kill grubs is June through early August, view Dr. Cranshaw's document below for more information on timing, cautions, etc. Only one application is generally needed each summer.

Insecticide and Biological Control Options for Control of Japanese Beetle Larvae (White Grubs) in Lawns

Document by Dr. Whitney Cranshaw, Colorado State University