Hello Matt,

Check out this information from the University of Massachusetts - Effective treatments at this link: https://ag.umass.edu/landscape/fact-sheets/beech-blight-aphid

Also, If you have a large tree that is infested, find a landscape or pesticide professional to apply the insecticide.

Just thought you might also like this information - Beech blight aphids vs. beech scale - Their impact on beech bark disease by comparing the two.

Insect feeding of a different sort can result in a beech tree having certain “fuzziness” on its branches or trunk. The color of this “fuzz,” however, is usually much darker than what is found from the scale insect that carries beech bark disease. It may look like unusual dark streaks or blobs on mature beech trees. The cause of these fuzzy streaks may be the result of a different insect: the beech blight aphid. Just like the beech bark disease-based scale insect, these aphids crowd together on major branches or other parts of the tree to feed on the sap. Since the beech blight aphid does not carry a nectria fungus infection, however, these insects rarely kill mature trees. Beech bark disease is a fungus spread via a scale insect. Beech bark disease is a fungus spread via a scale insect. Specifically, at least two different species of nectria fungus (accidentally introduced to the U.S. via European nursery stock in the late 1800s) are introduced into susceptible beech trees via the beech scale, a tiny sap-feeding insect that pierces the thin bark of the tree. The fungus introduction results in canker development that eventually cuts off the flow of water and nutrients, killing the tree over the course of a few years.

Beech blight aphids excrete a ‘honeydew’ that attracts a sooty mold fungus. This fungus does not harm the tree.

Beech blight aphids are also larger than the scale insect. They sport white, wooly hairlike filaments on their posteriors. As they feed together, they excrete what is called honeydew that accumulates on the bark or base of the tree. A sooty mold fungus then grows where these aphid “deposits” are found, thus creating that fuzzy dark effect. One of the more curious characteristics of this aphid is that it will wiggle its white posterior when threatened. A colony of these wiggling aphids can make quite a scene. A YouTube video hosted by Capital Naturalist demonstrates this effect. This quirky behavior gives these aphids the more colorful name of the “boogie-woogie” aphid.

Complete article at this link: https://www.canr.msu.edu/news/is_it_beech_bark_disease

Other references:

Biology and Management of Beech Bark Disease at this link: https://www.canr.msu.edu/uploads/files/e2746.pdf

Beech bark disease at this link: https://www.canr.msu.edu/ipm/uploads/files/WoodyLandscape_PDFs/BeechBarkDisease.pdf

Hope this helps!!