Damage:
Japanese beetles chew holes in leaves, often devouring much of the foliage from roses and other favored plants. When they stop feeding in late summer, the larvae (grubs) become a problem in lawns, where they damage grass by eating roots.
Preventing Problems:
Use row covers to protect plants during the 6 to 8-week period while Japanese beetles are feeding. Plan to hand pick often, by knocking the beetles into a bowl of soapy water. A fungal disease called milky spore can be introduced into lawns, where it infects Japanese beetle larvae.
Managing Outbreaks:
Japanese beetle populations vary from year to year. Although traps will collect hundreds of beetles, they may attract beetles from far beyond your yard.
Tips:
Pole beans often are damaged by Japanese beetles, but because the infested leaves are at eye level, the beetles are easier to gather.
