Black holes in aspen trees?

Asked November 30, 2019, 11:17 AM EST

My aspen trees have gotten what looks like sores on their branches. It’s hard to describe, I have pictures. It starts out looking like a black, swollen spot on the branch. Then it gets big black holes. I have seen small ants on the branches but nothing in the effected areas. I pruned off everything I could reach but they are not looking good.

Howard County Iowa

1 Response

I recommend taking two or three additional photographs (include the entire tree in one photo) and send the photos to the ISU Plant and Insect Diagnostic Clinic (

Aspens oftentimes don't perform well in Iowa. They are susceptible to several diseases which drastically shortens their lives.