Summary ²

Cecidomyiidae (sometimes spelled Cecidomyidae) is a family of flies (order Diptera) known as gall midges or gall gnats. As the name implies, the larvae of most gall midges feed within plant tissue, creating abnormal plant growths called galls.

The Goldenrod Gall Fly (http://bugguide.net/node/view/10482) specializes on goldenrod: the gall protects the larvae from parasitoids and predators, as well as providing an overwintering site. Here's a BugGuide photo of a goldenrod gall:
http://bugguide.net/node/view/457549

Sources and Credits

1. (c) Mick Talbot, some rights reserved (CC BY), http://www.flickr.com/photos/25258702@N04/3368989550
2. Adapted by maebbert from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Cecidomyiidae

More Info

• iNat taxon page
• Atlas of Living Australia
• Biodiversity Heritage Library
• BOLD Systems BIN search
• Field/Photo ID for Flies
• Global Biodiversity Information Facility (GBIF)
• Systema Dipterorum

iNat Map