The adult Japanese beetle may feed on more than 275 species of plants. The grub, or immature larval form, is the most serious turf grass pest.
Grubs feed underground on the roots of grasses and a wide range of other hosts.
The Japanese beetle has an annual life cycle. Adult beetles emerge from the soil beginning in early June. Peak numbers usually occur in July. Adult numbers in large infestations mean high grub feeding in August and September. Grubs reduce their feeding as the weather cools and days grow shorter.