Jessica Mathews / news@whmi.com


A new detection of invasive hemlock woolly adelgid was recently verified near Torch Lake in western Antrim County.

The Michigan Department of Agriculture and Rural Development made the announcement.

The extent of the infestation has not yet been determined, but an extensive survey of the surrounding area is underway. With the new detection, Antrim becomes the seventh county in the state with an active infestation - joining Allegan, Benzie, Mason, Muskegon, Oceana, Ottawa, and Washtenaw Counties.

Hemlock woolly adelgids are small insects that use their long, siphoning mouthparts to extract sap from hemlock trees. Their feeding weakens needles, shoots, and branches. Over time, tree growth slows, and trees take on a grayish-green appearance. Without treatment, infested trees die within four to 10 years.

MDARD’s Pesticide and Plant Pest Management Division Director Steve Carlson said the new infestation was found by a landowner who learned about the hemlock woolly adelgid while attending an educational outreach – adding situations like this demonstrate the importance of public awareness in the fight against invasive species.

Hemlock woolly adelgid can be identified by looking on the undersides of hemlock branches for evidence of round, white ovisacs near the base of the needles. Up close, ovisacs look like balls of spun cotton and may appear alone or in clusters.

Carlson said Hemlock woolly adelgid likely arrived in Michigan on infested nursery stock from northeastern states. Though the tiny insects don’t move far on their own, they can be blown by wind or hitchhike on animals - in a similar way, cars, boats, or RVs parked under infested trees may be able to transport the insects to new locations.

Carlson added "if you’re headed outdoors, take simple measures like only parking in designated areas and cleaning your gear and vehicle before traveling. Also, remember to leave firewood at home and buy it locally at your destination.”

Suspected infestations should be reported by emailing MDARD at MDA-Info@michigan.gov or calling the Customer Service Center at 800-292-3939. People can also use the Midwest Invasive Species Information Network (MISIN) online reporting tool or download the MISIN smartphone app and report from your phone.

People should be prepared to report the location of infested trees and, whenever possible, take one or two pictures of infested branches to help confirm identification. To avoid spreading hemlock woolly adelgid, do not collect sample branches or twigs.