Hackberry Gall-maker ID Request - Agromyza deserta
Herring Run Watershed, Baltimore City County, Maryland, USA
May 15, 2015
Observed on a Celtis sp.
In the past I encountered a single stem that resembled a thorn as these do. I decided against posting that one in case it was simply an aberrant stem. Finding these examples yesterday I decided to submit for your consideration.