Subject: Insect on Carpinus caroliniana
Geographic location of the bug: Dekalb County, IL
Time: 03:56 PM EDT
Your letter to the bugman: Never seen this on my prairie.
How you want your letter signed: Jack Pizzo
We hope our response was not too late to save these benign Barklice or Tree Cattle. Generally when insects congregate like this, they are plant pests, but Tree Cattle will not harm your tree. They feed on lichens.