Researchers at the University of Missouri say Japanese beetle populations throughout the state are likely to increase in the coming year.

Entomologist Wayne Bailey with the University of Missouri says the imported beetles, are some of the most aggressive bugs that feed on plants such as flowers, shrubs and trees; and corn and soybean crops. He says most of the damage by the beetles is during their peak months of June and July.

“We do have grubs underground at this time and what is happening is that population moves to the west,” he says. “It tends to build exponentially, so if you have 20 (beetles) in an area, then you might have 200 and then 2,000 and before you know it, 20,000.”

Bailey says the beetles were originally imported in 1916 and has made its way in to the state since 1934; but they’ve mainly stayed in the St. Louis area…until they began to move west about 15 years ago. “And so, in Columbia, we didn’t have a lemon tree in town I don’t think last year that wasn’t stripped by the adult beetle feeding,” he says. “We’re seeing this all the way now to Kansas- Wyandotte County in Kansas has its first report.”

He says the beetles’ adult lifespan only lasts six weeks, and says the beetles can be sprayed to be killed as adult beetles but they often feed in very large groups, which might make it difficult to get rid of them.

 Adult Japanese beetles are measured to be a half-inch long with a metallic green and bronze- or copper-colored wings.

AUDIO: Mary Farucci reports. (1:00)