In the summer when giant ironweed (Vernonia gigantea, Asteraceae) is full of healthy nectar-laden blossoms, I’ve found it visited by silver-spotted skippers, cabbage whites, and other pollinating butterflies, bees, and wasps. Now that we’re well into autumn, the dried, dead plants still host other insects.
While out in a nearby floodplain forest here in southeast Michigan, I noticed a number of galls along the leaf midveins. Naturally I split some open to find out what insect was responsible.
I found the larvae of some unknown insect in the middle of the galls. I’ve made some effort searching the literature on leaf galls, but I have yet to identify this insect. At this point I suspect it’s a fly (order Diptera) and possibly a gall midge (family Cecidomyiidae).