Hemlock woolly adelgid (HWA) is an invasive insect native to eastern Asia that sucks sap from eastern hemlock tree branches and can kill a tree in 4 to 10 years if not treated. HWA can be identified by its white, cottony ovisacs on the undersides of hemlock branches, near the base of the needles. The ovisacs may appear alone or in clusters. Late fall through early spring is the best time to check hemlock trees for the presence of HWA.
Please see the following resources for help with identification, information, and reporting options:
- Hemlock Woolly Adelgid: Invasive Species in Michigan – A short video with identification tips.
- Michigan.gov/HWA – website with identification, look-alike and quarantine information, maps and more.
- SaveMiHemlocks.org – website of the West Michigan hemlock woolly adelgid taskforce
- For a two-sided, pocket sized HWA and hemlock tree identification card please visit Mason-Lake Conservation District at 655 N. Scottville Rd. in Scottville, or call (231)757-3707.
How to report trees infested with HWA:
Note the location of the tree and, if possible, take photos of the infested branch. To avoid spreading HWA, do not collect sample branches or twigs. Report the find using one of these methods:
- Email the Michigan Department of Agriculture and Rural Development at [email protected].
- Call the MDARD Customer Service Center at 800-292-3939.
- Use the Midwest Invasive Species Information Network (MISIN) online reporting tool or download the MISIN smartphone app.
- Contact Mason-Lake Conservation District for a free site visit!