Green, leafy bud gall...Rhopalomyia ambrosiae Gagné
This species causes a foreshortening of the stem. The gall has green leaves growing out of its apex...Specimens from Texas are somewhat different from the type series taken on A. artemisiifolia in Florida and may be a different species. Hosts: A. artemisiifolia, A. psilostachya.
”- Raymond J. Gagne: (1989) The plant-feeding gall midges of North America©