Hemlock woolly Woollyadelgid (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. You can see them with the naked eye, or use binoculars to see higher branches.

Invasive hemlock woolly adelgid has been found in Mason County. Thanks to collaborative efforts between the Michigan Dept. of Natural Resources, regional CISMAs (Cooperative Invasive Species Management Areas) and regional Conservation Districts, HWA was located in Summit Township and Ludington State Park in 2020. Treatments were underway in 2020 to protect the infested trees and those in surrounding areas.