Hemlock woolly adelgid spreads to Antrim

Jordan Travis, The Record-Eagle, Traverse City, Mich.
·3 min read

Mar. 20—BELLAIRE — Invasive insects already posed a threat to trees on Torch Lake's shoreline, and now the hemlock woolly adelgid has been verified in western Antrim County for the first time.

The Michigan Department of Agriculture and Rural Development announced the detection this week, noting an ongoing and extensive survey should determine the spread of the infestation. A landowner who learned about the insect at a Cooperative Invasive Species Management Area outreach event reported the outbreak, according to Steve Carlson, MDARD pesticide and plant pest management division director.

For Sherry O'Connor, the news was upsetting. She lives on the east side of Torch Lake and is already involved in keeping an eye out for another mortal danger to the towering red oaks on her property — oak wilt. She and a neighbor organized a group of people to keep an eye on each other's trees to detect a disease that can kill a tree quickly and is primarily spread by beetles.

Now, she'll be on the lookout for hemlock woolly adelgids, too.

"It breaks my heart, it really does, and I think we've got to stay vigilant on all these things," she said.

That makes Antrim the seventh county with an active infestation, including Benzie, of the tiny, sap-eating insect, according to MDARD. They feed at the base of hemlock needles, forming a waxy coating over winter that gives them their trademark appearance of cottony pinheads on the underside of hemlock branches.

In Sleeping Bear Dunes National Lakeshore, park administrators closed land all around Old Indian Trail after an adelgid (say: "a-DELL-jid") infestation first spotted on Crystal Downs Country Club in February 2023 spread to the national lakeshore, as previously reported. Surveys by the Cooperative Invasive Species Management Area that covers Benzie also spotted the bugs along Crystal Lake's shore.

David Roberts treats oak wilt extensively around the Traverse City area, and the retired Michigan State University plant pathologist said he has experience treating hemlock woolly adelgids elsewhere. He also discovered the emerald ash borer when it first started obliterating North America's ash trees.

Hemlock woolly adelgids' detection in Antrim County wasn't surprising to Roberts, who said they're probably present elsewhere and just haven't been spotted yet. That's even with CISMA surveyors and others conducting winter checks to find infestations.

"And so that's a good effort, but they probably are not detecting every outbreak in every township, for example," he said.

That's why it's important for people to learn what the insects look like, keep a lookout and report their findings, Roberts said. He regularly gives talks on oak wilt and other invasive plant pest-related issues.

Plus, MDARD has lots of information online for people who want to find out more. He also recommended people be extra cautious when buying hemlocks or any products containing them — Christmas wreaths, for example.

Roberts agreed that more neighborhood watch-type groups like the one O'Connor formed with Torch Lake neighbors could help with early detection.

"But you know, the public is kind of reluctant to do anything until they're actually affected by it, and it would be more beneficial, I think, if people took a more proactive approach," he said.