The number of Japanese beetles in Ohio this summer has been abnormally high, but thankfully they are expected to soon be on their way out. 

According to Joe Boggs, an entomologist with Ohio State University Extension, said there have been outbreaks in Cincinnati, Dayton, and Columbus, as well as northeast Ohio.

A recent report stated that although Japanese beetles are usually found on the leaves of linden trees, grape vines and roses, this summer, they branched out, devouring other plants in Ohio including scotch pine and jewelweed.  

"Sometimes during outbreaks, they'll feed on strange things," Boggs said, in a recent report

The report stated that with their iridescent copper bodies and green heads, Japanese beetles can be easy to spot, but hard to get rid of.

Flicking them away with your fingers doesn't always work because they generally return. 

About the only way to keep them off plants without using pesticides is to pull them and dunk them into a container of soapy water, Andy Michel, an entomology associate professor in CFAES, said. 

On a soybean plant, even if they remove the leaves at the top, as long as the sun can filter down to the lower leaves, the plant can still perform photosynthesis and remain healthy. 

For commercial soybean growers, a pesticide isn't necessary unless about 30 percent of each leaf is gone on the majority of the plant before it has flowered or 20 percent after it has flowered, Michel continued in the report.

Michel said that a pesticide may also be necessary on corn plants if the beetles eat the silk of corn, leaving less than a half inch, or if the beetles are numerous and feeding while fewer than half of the corn plants have been pollinated.

Whatever damage they may have done, Japanese beetle populations are significantly decreasing now as they tend to do in late July and August.