St. Paul warned residents Wednesday about an influx of door-to-door contractors who are telling residents they have better information and treatment than the city and state for the emerald ash borer.

St. Paul Parks and Recreation and the Minnesota Department of Agriculture confirmed Monday the invasive tree killer had been found in six trees near Summit Avenue and Dale Street, three miles from previously confirmed infestation sites. The latest confirmation has brought reports of new door-to-door vendors reportedly claiming to be affiliated with the city.

The city warns that the for-profit door-to-door vendors are not authorized by St. Paul or the state.

If contacted by a vendor, the city suggests residents ask for identification, because all city forestry staff carry ID cards. If the vendor doesn't have proper identification, the city suggests taking their name and calling the city.

"If the vendor does not identify themselves as working for the city, residents can certainly make their own decision on the products they may be selling for private use," parks spokesman Brad Meyer said in an e-mail to neighborhood groups.

Although the spread of the borer wasn't unexpected, the St. Paul infestation had previously been confirmed only in St. Anthony Park. All 100,000 ash trees in the city are at risk of infestation and death from the insect, which feeds on a tree and chokes off its nutrient supply.

Residents with questions about treatment for ash trees can visit Insecticide information is available at

The city recommends all work done on private property be performed by a certified arborist. The city's forestry hotline is 651-632-5129 or e-mail at

The state is awaiting a shipment of Chinese wasps from Michigan and is expected to release them near Summit Avenue as early as Friday. The wasps are a natural predator to the borer in their native Asia.

Rochelle Olson • 651-925-5035 Twitter: @rochelleolson