07/18/17 Stem galls on joe pye weed (Eutrochium) in a wetland; one gall collected for rearing. A larva from a second gall was removed from its gall and reintroduced to a section of Eutrochium stem (an experiment) but did not survive.
08/05/17 Adult

I knew to look for these galls after finding old ones on Eutrochium dead stems at the same site last winter. At that point the galls contained empty puparia, suggesting the flies had emerged during the previous growing season.