A new lawn is sometimes an invitation to a Japanese beetle milky spore, which causes milky spore disease in the Japanese beetle larvae. Treat the lawn just before a rain. Larvae are grayish-white grubs with brown heads and six legs. Look for signs of their sawdustlike excrement outside their entrance holes. Moths lay their eggs near the base of plants and hatch in nine to 14 days.
Caterpillars tunnel into stems and feed for up to six weeks, then pupate in the soil.
The adult moth emerges in late June. Use fall plowing to destroy pupae. Harvest fruit as soon as full grown. Use pheromone traps to monitor for adult moths. As armored scales feed, they can also inject toxic saliva into plants.