Turfgrass Entomology (japbtl)

larva adult damage

Japanese beetles, Popillia japonica, were introduced into Nebraska on infested nursery stock in the early 1980's. Japanese beetle larvae feed on the roots of a wide range of grasses and woody ornamentals and are one of the most destructive pests of turf, landscapes and nursery stock in the northeastern United States. Japanese beetle adults are also voracious plant feeders and are capable of damaging the foliage, flowers and fruit of nearly 300 plant species. This is in contrast to the three white grub genera previously discussed whose adults cause little or no plant injury. The life cycle, damage symptoms and timing of treatment for the Japanese beetle are similar to those of the masked chafer. Adults are active from late June through early August. During daylight hours, they often feed in clusters on host plants such as apple, grape, rose and linden. Eggs are deposited during July and early August with the majority of turf damage occurring in late summer and fall. Japanese beetle grubs overwinter below the frostline in the soil. There is a single generation each year.