Western Michigan’s coldwater streams rely on eastern hemlock, a keystone species that cools water, stabilizes banks, and provides vital habitat. That makes the spread of hemlock woolly adelgid (HWA), a pinhead-sized insect that threatens these trees, especially concerning. Julia Place, Project Manager of the Hemlock Woolly Adelgid Crew for the Mason-Lake Conservation District, leads a team working urgently to slow the infestation and protect local forests.

“Once HWA infests a tree, it’s pretty much 100% lethal without treatment,” explained Place. “It can kill them within about four to ten years.”

Protecting a cornerstone species

Using Good Neighbor Authority (GNA) funding with the U.S. Forest Service and the Michigan Invasive Species Grant Program (MISGP), the district surveys, tags, and treats hemlocks across Mason and Lake counties. Crews prioritize riparian corridors, wetlands, and recreation sites—areas where HWA spreads easily through wind, wildlife, and human activity.

Treatments are delivered through trunk injections or targeted sprays. It takes about a year for the chemical to reach the canopy, with improvement often seen within one to two years.

“We have photos where one side of a road was treated and the other wasn’t—the difference in needle loss is striking,” said Place.

Their treatment concentration provides roughly five to seven years of protection.

Exceeding expectations

Each winter, crews tag hemlocks and record diameter at breast height (DBH), GPS location, and field notes. In summer, they return to those exact trees to treat them. This process has helped Mason-Lake significantly exceed project goals.

A recent MISGP award aimed for the treatment of 10,000 hemlocks and 90,000 DBH inches; the district treated about 15,000 trees and more than 119,000 inches. Another grant, targeting 45,000 inches reached 92,000 this summer. Under GNA, crews approached 100,000 inches, more than double their goal.

These results stem from strong collaboration with Ottawa and Muskegon Conservation Districts, the Northwest Invasive Species Network, the Michigan DNR, and the U.S. Forest Service.

“Everybody knows everybody,” said Place. “Those relationships make it easy to stay consistent.”

Meeting landowners where they are

The district blends digital outreach with neighbor-to-neighbor communication. Social media updates, buffer-zone mailers, and postcards with QR codes help residents request assistance quickly.

Once a landowner reaches out, the process is simple: an initial site visit, a quote, a one-page agreement, winter tagging, and summer treatment. Early confusion around paperwork led the team to overhaul their forms.

“We did a complete 180,” said Place. “We cut out the jargon and made it easier for people to understand.”

The front line moves north

When HWA was first detected in western Michigan, Mason and Lake counties sat near the leading edge. Today, the infestation has spread into at least 13 counties, shifting the priority zone north toward the Traverse City and Leelanau region. Crews are working to prevent HWA from reaching Michigan’s Upper Peninsula (U.P.).

“Our goal is to slow the spread and keep it out of the U.P. as much as possible because it would just decimate those hemlocks,” said Place.

With funding priorities moving north, Mason-Lake is transitioning from grant-funded work to more fee-for-service contracts. Still, Place emphasized the long-term need: “Even though we may not be a priority area anymore, we’re not done. Once HWA is in an area, there’s always going to be work to do.”