Hemlock Wooly Adelgid
Why is our state tree (the Eastern Hemlock) in trouble? The Eastern Hemlock is being attacked by the Hemlock Wooly Adelgid. This invasive aphid-like insect kills Hemlock by feeding on their starch reserves and injecting a toxin into them that causes their needles to drop more quickly. According to the article âRehabilitation Guidelines for Hemlock Stands,â âAdelgids cause damage by depleting the Hemlockâs starch reserves.â When the starch reserves are depleted, the tree doesn t have enough energy to grow. The Hemlock Wooly Adelgidâs toxin causes needles to fall off the tree faster, as shown in the article âForest Health Fact Sheetâ. With less needles to perform photosynthesis in and not enough energy reserves to grow new ones, the tree is unable to store enough energy to live well through the dark winters, and it dies within a few years.
Invasive hemlock woolly adelgid found in northern Benzie County
The Michigan Department of Agriculture and Rural Development recently verified a new detection of invasive hemlock woolly adelgid at the Sleeping Bear Dunes National Lakeshore in northern Benzie County. To date, a survey of the surrounding area has found just one infested tree in the Platte River Campground, a popular destination within the National Lakeshore.
Hemlock woolly adelgids are small insects that use their long, siphoning mouthparts to extract sap from hemlock trees. Their feeding weakens needles, shoots and branches. Over time, tree growth slows, and trees take on a grayish-green appearance. Without treatment, infested trees die within four to 10 years.