The culprit is Asian wooly hackberry aphids, which live on hackberry and sugarberry trees.
From the tennessean.com
Heading north toward Bourbon County, the road veers slightly to the left to accommodate a state champion sugarberry.
From the kentucky.com
The surrounding park has two miles of nature trails that lead to the largest cluster of white oak trees east of the Mississippi River and the largest sugarberry tree in Alabama.