BISMARCK, N.D. (AP) — A bug that's an enemy to flower beds, gardens, crops and even golf courses has been found again in North Dakota. An insect expert says the state likely now has an established population of the destructive Japanese beetle.

WHAT IS THIS PEST?

The beetles that are native to Japan were first found in the U.S. in New Jersey in 1916. Over the past century, they have spread west to the central Plains, according to the federal Animal and Plant Health Inspection Service.

The bug was first found in North Dakota in 2001, and then not again until 2012. Last year, beetles were found in traps in 15 counties around the state, according to Janet Knodel, entomologist with the North Dakota State University Extension Service.

No trapping was planned this year, but the state Agriculture Department on Tuesday announced that beetle larvae were found in nursery stock in the state. The beetles were found in Bismarck and other locations that received shipments from the same source, according to spokeswoman Michelle Mielke.

WHERE ARE THE BUGS COMING FROM?

Knodel said the beetle larvae were in shipments from the Minneapolis area. Some beetle discoveries in North Dakota in previous years also have been tied to that state.

The beetles have been in Minnesota for decades and became abundant in the Twin Cities area in 2011, according to that state's Agriculture Department. The bug also is established in parts of South Dakota.

Montana isn't known to have a Japanese beetle population. It's among nine Western states listed under a federal Japanese beetle quarantine that regulates aircraft flying from infested states to try to stop the westward spread of the pests.

HOW BIG OF A DEAL IS THIS?

If North Dakota now has an established population of the beetle, it could be a major problem, and "we do feel it's established in the major cities that have had a lot of container stock (nursery) shipments," Knodel said.

The bug attacks more than 300 different ornamental plants and grasses, fruits and vegetables, trees and agricultural crops including corn and soybeans. The adult defoliates plants; the grubs feed on plant roots.

"It's estimated to cost approximately $450 million (in damage) each year in the U.S.," Knodel said. "It's a major destructive plant pest."

Once the bug establishes itself in a state, it takes several years or it to become prevalent enough to cause major economic damage, she said.

CAN IT BE CONTROLLED?

The beetle can be controlled with insecticides, though more than one application might be necessary.

"The adult has quite a wide window when it's active — July through early August, four to six weeks when it's present," Knodel said.

Japanese beetle grubs spend the winter in the soil, emerging as adults in late June.

There are established infestation thresholds for spraying agricultural crops, Knodel said.

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Japanese beetles: http://bit.ly/2siDFQf

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