Michigan fights invasive balsam woolly adelgid

Thursday, October 26, 2023

The invasive balsam woolly adelgid (BWA) is a tiny sap-feeding insect that attacks true fir trees, including balsam, Fraser, and concolor (white) fir. The pest is not native to Michigan, but it was first identified in the state in 2001. Since then, it has spread to three counties: Kent, Missaukee, and Oceana.

BWA is a serious threat to Michigan's forests and horticulture industry. The pest weakens trees, kills branches, and can eventually kill the entire tree. Nearly 1.9 million balsam fir trees populate Michigan's forests, and Fraser and concolor fir trees are often planted on landscapes.

Symptoms of BWA infestation include:

Tiny white woolly tufts on the lower trunk of the tree and possibly on large branches in the spring and summer
Swelling and distortion of the twigs, commonly called "gout"
Flagging, where a branch or branches turn brick-red and die
Tree crowns that become narrow and misshapen with few needles

If you suspect that a fir tree on your property may be infested with BWA, it is important to contact the Michigan Department of Agriculture and Rural Development (MDARD) immediately. MDARD can help you identify the pest and recommend treatment options.

How to help prevent the spread of BWA:

Avoid transporting firewood. Firewood can harbor BWA and other pests. If you must transport firewood, buy it from a local source and burn it within the same county where you bought it.
Inspect fir trees for signs of BWA infestation before buying or planting them.
Report any suspected BWA infestations to MDARD immediately.

By working together, we can help protect Michigan's forests and horticulture industry from this invasive pest.

Michiganders are encouraged to report any suspected balsam woolly adelgid damage promptly. Take photos, note the location, and report it to the Midwest Invasive Species Information Network or MDARD at MDAInfo@michigan.gov, or call 800-292-3939.

For more information on balsam woolly adelgid and other invasive species in Michigan, visit Michigan.gov/Invasives.

Photo Credit: pexels-deep-malik