The green, bristly, onion-shaped capitulum galls are situated among normal capitula and can sometimes be found in aggregations. They were recorded by Felt (1907a, 1915) from S. altissima in North Carolina, and Gagné (1989) reported similar galls on S. fistulosa from Florida, which he attributed tentatively to the same species. The description of the galls and the mention of previous records of this species in Felt (1915) actually refer to the galls of Schizomyia racemicola rather than those of R. racemicola (see Gagné 1971). The true nature of [Felt's 1907] R. racemicola galls is therefore uncertain, and we tentatively adopt Gagné’s assumption that the galls he received from Florida are those of R. racemicola. Adults emerged in mid September in North Carolina, and in December in Florida. Given that the galls develop in capitula, we assume that R. racemicola is univoltine, but verifying the identity of the host plant and the galls, and clarifying the life history of this species require more investigation.

- Netta Dorchin, Miles V. McEvoy, Todd A. Dowling, Warren G. Abrahamson, Joseph G. Moore: (2009) Revision of the goldenrod-galling Rhopalomyia species (Diptera: Cecidomyiidae) in North America^©