Single, deformed, lateral floret...Rhopalomyia sp.
Galls are 2β4 mm long and 2 mm in diameter. Adults probably emerge from galls in autumn. Host: A. undulatus. Distr.: Massachusetts. Ref: Felt (1940)
β- Raymond J. Gagne: (1989) The plant-feeding gall midges of North AmericaΒ©