LANSING, Mich. (AP) — Michigan officials are sounding the alarm about scam artists trying to buy black walnut trees.

The Department of Natural Resources and the Department of Agriculture and Rural Development say dishonest log buyers are telling woodlot owners that Michigan’s black walnuts have been invaded by Thousand Cankers Disease.

The fatal disease is caused by small beetles that bore into walnut branches and introduce a fungus.

Officials say Thousand Cankers Disease has not been detected in Michigan.

A quarantine was established five years ago to protect the state’s black walnuts.

Michigan’s forests have about 8.5 million black walnut trees with an economic value of more the $86 million. They’re an important food source for birds, mammals and other wildlife.