At the lush gardens at Miller House in downtown Hagerstown, where Peters works as executive director of the Washington County Historical Society, beetles have not been a problem, however.
"There are some hot spots," said Sandy Scott, horticultural expert at the University of Maryland Cooperative Extension Service in Hagerstown.
Scott and other Tri-State area extension agents have fielded hundreds of calls in the past week about Japanese beetles, they said.
Last year's wet weather provided ideal conditions for the beetles to breed by laying eggs in moist soil, Scott said.
"Apparently, every egg that was laid made it," she said.
One female can produce 40 to 60 eggs. The eggs hatch into grubs, which become beetles in early summer.
This year, beetle season arrived a little late, probably because of the cool spring, she said.
But when it arrived, it came with a vengeance.
"The people with roses know that in a hurry," said Bill Reagan, senior extension agent in Franklin County, Pa.
Japanese beetles are attracted to hundreds of different kinds of plants. Favorites include Japanese or Norway maple trees and any kind of fruit tree.
They also like poison ivy, which might be their only benefit to gardeners.
When a beetle finds a plant that it likes, it emits a hormone that acts like the ringing of a dinner bell.
Possibly the biggest myth about Japanese beetles is that traps will solve the problem, extension agents said.
Chris Tischer of the Hagerstown Garden Club just set up two traps at her house on Blue Heron Lane north of Hagerstown.
The traps catch and kill so many beetles every day that people believe they are working, Scott said.
It's such a common misconception that even the West Virginia Agriculture Commissioner recommended them in his most recent newsletter, said Mary Beth Bennett of the Berkeley County (W.Va.) Agriculture Extension Office.
"The truth is, they pull them in from a mile or two around them," Bennett said. The trap lures and captures the males, but leaves the females free to lay eggs in the yard.
Scott said the traps might work if everyone in the neighborhood uses them.
Applying pesticides on plants works better, she said. Although Sevin is the most effective, it's also toxic to honey bees that are in short supply for pollination these days, she said.
Other chemical and organic pesticides are available. Or knock the beetles off the plants and into a pail of soapy water, she said.
June Wagner, who belongs to garden clubs in Hagerstown and Fountain Head, said she discovered a problem on her oak trees three or four days ago.
Spraying Diazinon seems to have killed the beetles, said Wagner, who lives on Millers Church Road.
On her roses, Wagner uses Ortho systemic powder, which seems to stave off all kinds of insects.
Accompanying the Japanese beetle boom is an increase in the population of green June beetles, Scott said.
Those beetles are larger, green or brown metallic bugs that also feed on certain types of plants, she said.