DNR: Invasive insect, hemlock woolly adelgid, confirmed in 5 Michigan counties
LANSING, Mich. (CBS DETROIT) - There's a growing threat to hemlock trees in Michigan, but there is a way to protect them.
The Michigan Department of Natural Resources (MDARD) is encouraging residents who have eastern hemlock trees on their property to take time this winter to inspect the tree for signs of hemlock woolly adelgid.
Infestations of hemlock woolly adelgid have been confirmed in Allegan, Ottawa, Muskegon, Oceana and Mason counties, all bordering Lake Michigan. Officials say infested trees can die within four to 10 years without treatment.
Robert Miller, MDARD invasive species prevention and response specialist, says the winter season is the best time to check for infestation.
"Cooler temperatures trigger feeding activity," Miller said in a press release. "As hemlock woolly adelgids feed, they secrete a white, waxy material that creates ovisacs. The presence of these small, round, white masses makes it possible to identify infested trees."
The insects are considered invasive due to not being native to Michigan. They can also cause significant to Michigan's estimated 170 million hemlock trees.
Officials say survey crews will check for signs of the invasive insect and conduct surveys within a 5-mile board along the Lake Michigan shoreline.
Since adelgids feed and form ovisacs only on eastern hemlock trees in Michigan, it is important to distinguish hemlocks from other conifers like pines or spruces.
• Cone- or egg-shaped trees up to 75 feet tall.
• Drooping or feathery branches.
• Flat needles growing individually from the sides of twigs.
• Needles that are dark green on top with two parallel, white stripes underneath.
• Papery cones about three-quarters of an inch long that hang downward from branches.
Report infested hemlock trees by using the Midwest Invasive Species Information Network, available online at MISIN.MSU.edu or as a downloadable smartphone app. The MISIN smartphone app will take a GPS location point if a report is made at the site; it also will allow you to upload photos with a report.
Reports also can be made by emailing MDA-Info@Michigan.gov or calling MDARD's Customer Service Center at 800-292-3939. The report should include the location of the infested tree and one to two photos of the branches. Residents are advised not to collect sample branches or twigs to avoid a spread.
For more information on identification, reporting or treatment, visit the Michigan Invasive Species Program's hemlock woolly adelgid page at Michigan.gov/HWA.
