Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Photo#333457
Cecidomyiidae, Solidago flower galls - Rhopalomyia anthophila

Cecidomyiidae, Solidago flower galls - Rhopalomyia anthophila
Lake Hawthorn, Mahaska County, Iowa, USA
September 10, 2009
Size: 6+ mm
I've been seeing these galls on Goldenrod, Solidago sp., a lot this year. Gagne's book, "The Plant-Feeding Gall Midges of North America" keys: Solidago, bud or flower gall, galls cylindrical-not formed of leaf rosette, modified floret, gall widest at base-fuzzy = Rhopalomyia anthophilia. I'm most interested in the 2 larvae inside of the one gall I cut open: a fly and a parasitoid wasp perhaps?

Later: emergence of adult flies: and several parasitoids:
Pteromalidae Torymidae Platygastridae

Images of this individual: tag all
Cecidomyiidae, Solidago flower galls - Rhopalomyia anthophila Rhopalomyia anthophila, Solidago flower gall with 2 larvae - Rhopalomyia anthophila Rhopalomyia anthophila, Solidago flower gall with 2 larvae - Rhopalomyia anthophila Rhopalomyia anthophila larvae + parasitoid - Rhopalomyia anthophila Rhopalomyia anthophila larvae + parasitoid - Rhopalomyia anthophila

Moved
Moved from ID Request.

Rhopalomyia anthophila galls
Wow! that's the most amazing infestation of R. anthophila that I've seen. As part of my recent revision of this group of gall midges, I found this species only once in NY, where it was rather rare. Nice to know it occurs in such numbers elsewhere.
The white larva in the gall is that of the gall midge and the smaller, more orange larvae is a parasitoid.