Asteromyia tumifica

Asteromyia tumifica is a species of gall midges in the family Cecidomyiidae. This fly causes blister galls on green stems  at the base of goldenrod stems. It has a fungal symbiont responsible for forming a black, hard cast around full-grown larvae. The fungi are transported by the female midges in the ovipositor and spores are transferred at the time of egg insertion into the stem.