Back without popular demand: Here comes the annual showing of Japanese beetles, the embodiment of beauty and the beast rolled into one. The four- to six-week period of intense activity by the gleaming, copper-colored adult Popillia japonica is underway.
These beetles may seem to have it in specifically for your roses, raspberries, crab apples or grapes, but those are just a few of the 300-plus plant species they are known to feed on in North America.
The expert advice might sound counterintuitive: Stop trapping them. (Farewell, beetle bags, despite the marketing promises.) And maybe hold back on watering lawns in the July heat, as female beetles will be seeking a moist spot to lay eggs.
a 2015 U.S.D.A. homeowners’ guide to Japanese beetle management put the cost of control in the United States — including the removal and replacement of damaged turf — at $460 million annually. Half of that damage is caused not by the adults, but during the beetles’ larval stage, by the grubs.
quarantines are currently in effect on shipping nursery stock to nine Western states from 28 Eastern ones and the District of Columbia.