Update, 3:17 p.m. Wednesday: A Sept. 4 EAB open house has been scheduled for Nobles County residents. Residents may attend between 6 p.m. and 8 p.m. in the Farmers Room of the Nobles County Government Center, 315 10th Street, Worthington. Attendees will have the opportunity to learn more about EAB, local options to deal with the bug and ask questions to experts.

The public will also have an opportunity to provide input to the county's formal quarantine. MDA will accept comments on the proposed formal quarantine through Sept. 25, with plans to adopt the formal quarantine Oct. 1.

Input may be directed to Kimberly Thielen Cremers, Minnesota Department of Agriculture, 625 Robert Street North, St. Paul; kimberly.tcremers@state.mn.us.

WORTHINGTON — The first case of emerald ash borer has been officially discovered in Worthington, state officials confirmed Wednesday.

According to Minnesota Department of Agriculture entomologist Angie Ambourn, a sample was collected last week from an ash tree within Pioneer Village by a Minnesota Department of Natural Resources forester. Ambourn was unaware how the beetle-infested tree was discovered, but the MDA was provided photos and a sample to be tested by the United States Department of Agriculture. The positive test result was received Monday.

“If you look at how emerald ash borer has been spreading across the state, it isn’t uncommon to find it along interstates,” said Ambourn, who is the supervisor of the pest detection and export certification unit within the plant protection division. She added that that indicates the disease is likely spread through human assistance.

The location of the Worthington find has been identified as a “generally infested area” to the MDA’s online emerald ash borer status map. The map shows other locations across the state with confirmed infestations. The closest to Worthington prior to last week’s discovery was along the interstate near Welcome in Martin County.

The invasive beetle larvae feed on the inner bark of the tree, severely impeding the ash tree’s ability to transport water and nutrients. According to MDA, Minnesota is highly susceptible to the destruction caused by EAB, as it's approximate one billion ash trees is the most of any state in the United States.

Pictured are the holes generated by emerald ash borer. They must have a flat bottom, or "D" shape. (Special to The Globe)
Pictured are the holes generated by emerald ash borer. They must have a flat bottom, or "D" shape. (Special to The Globe)

According to the Minnesota Department of Agriculture’s EAB program, the disease is spread through a short distance by natural flight. It is also spread long distance by transporting infested firewood.

Due to the discovery, Nobles County will be added to a list of quarantined counties. As that formal process gets under way, the county has been placed under an emergency quarantine, Ambourn said.

The purpose of the quarantine, Ambourn explained, is to limit the transportation of firewood and ash out of an infested county.

Ambourn said MDA will be working closely with the county and city of Worthington to provide resources and survey other ash trees.

If area residents believe they have an EAB infested tree, they may report it to the state’s Arrest the Pest plant protection program: 1-888-545-6684; Arrest.the.Pest@state.mn.us

Reports may also be made on the Great Lakes Early Detection Network app, which is available to download on smart phones.

Further EAB information is available on the MDA’s website.

Check back for updated reports.