Hemlock Wooly Adelgid Found In Leelanau County

Hemlock wooly adelgid (HWA) has been spotted in Leelanau County, according to an announcement this week from the Michigan Department of Agriculture and Rural Development (MDARD). Per a press release sent out Thursday by the Michigan Invasive Species Program, MDARD “recently verified a new detection of invasive HWA on trees on a private property in Leelanau Township in Leelanau County.” The finding marks the first HWA infestation on record in Leelanau County, and makes Leelanau the ninth county in the state with an active HWA problem.

HWA is an invasive aphid-like insect that, despite being native to Asia, found its way to North America in the 1950s and has been spreading ever since. Infestations of the pest in hemlock trees or spruce trees can quickly drain those trees of important nutrients. HWA suck the sap out of the trees, literally starving them. An infestation severe or long-running enough can cause needle loss, stunted tree growth, and eventually, death of the infested tree or trees. An HWA infestation can kill a hemlock tree in as little as four years.

According to the Michigan Invasive Species Program, the extent of the infestation in Leelanau Township “is currently being assessed through survey of the surrounding area.” In addition, the entire county “has been added to the statewide HWA quarantine” list, which “restricts the movement of hemlock nursery stock and unprocessed hemlock material from quarantined areas.”

While this instance marks the first detection of HWA in Leelanau, the county has been on high alert for HWA for several years. In 2018, HWA was discovered within Sleeping Bear Dunes National Lakeshore for the first time ever, in a single tree at the Platte River Campground. The National Park Service announced another HWA infestation within the National Lakeshore earlier this year, on the Old Indian Trail. But both of those infestations were technically in the northern reaches of Benzie County, not in Leelanau County.

Those who suspect they may have an HWA infestation on their property, or who think they have spotted signs of HWA out and about in Leelanau County or anywhere in the state, are asked to report their findings. Reports can be made via email (MDA-Info@Michigan.gov), by phone (800-292-3939), or by using the Midwest Invasive Species Information Network’s online reporting tool or mobile app.