Rhopalomyia racemicola and Schizomyia racemicola have a confusing nomenclatural history involving at least three distinct entities. Here is a summary:

1. Osten Sacken (1862) - Describes Cecidomyia racemicola, based on its "bud-shaped gall among the racemes of Solidago." He does not base the description on insect material, but does note one reddish larva per gall.
2. Felt (1907) - Describes Rhopalomyia racemicola, based on male and female adults reared from "subglobular turnip-shaped bud galls on Solidago canadensis taken at Asheville, N.C." These adults were reared the same season he collected the galls. There is no description of larvae or pupae. The gall and adult descriptions are not detailed. His "S. canadensis" is probably S. altissima as it was collected in North Carolina.
3. Beutenmüller (1907) - Describes a bright orange larva in detail from galls that were "green, smooth, rounded, tapering to a point at the apex, giving it a bud-like appearance." Assigns these to Cecidomyia racemicola, following Osten Sacken. Like Osten Sacken, he notes that there is a single larva per gall. He notes further that the larvae exit the gall to pupate in the soil. He decides that the adults described by Felt as Rhopalomyia racemicola are "probably the gall makers of Cecidomyia racemicola O.S." and reduces R. racemicola to synonymy.
4. (intervening decades - Cecidomyia racemicola apparently transferred to Rhopalomyia racemicola when the genus Cecidomyia is broken up. (?))
5. Gagné (1971) - Examines "typical racemicolous galls from Solidago stricta" in Florida and determines that the larvae contained therein are not the generally whitish larvae of genus Rhopalomyia, but rather the red-orange larvae of the genus Schizomyia. Assignment to Schizomyia was based on details of larval anatomy and the fact that they exit the gall to pupate. He transfers Cecidomyia racemicola in the sense of Osten Sacken [the type material included identifiable larval remnants] to Schizomyia racemicola and notes that Felt's Rhopalomyia racemicola, contrary to Beutenmüller, must refer to some other species associated with apparently similar (or even the same) galls. Based on the location of Gagné's Schizomyia collection in Manatee Co., FL, "Solidago stricta" probably now refers to Solidago virgata.
6. Gagné (1989) - Reports the discovery of late-season galls on the stems and flowering branches of Solidago fistulosa that are broadly consistent with Felt's (1907) gall description, and rears adult females from them (pupating within the gall) that are consistent with Felt's insect description and type series, but difficult to match with certainty. He tentatively assigns Rhopalomyia racemicola to these new galls.
7. Fontes et al. (1994) - Describe the discovery of early-season galls (and some insect material) on Solidago fistulosa.
8. Dorchin et al. (2009) - Re-describe Felt's (1907) Rhopalomyia racemicola adults in much greater detail, and note that Felt's later works confused the galls of what is now known as Schizomyia racemicola with whatever galls he actually reared R. racemicola from. They note that Felt's adult specimens most closely resemble R. anthophila, R. cruziana, and R. guttata. They agree with Gagné's 1989 suggestion that Rhopalomyia racemicola in Felt's original sense is responsible for the late-season galls on Solidago fistulosa. They are hesitant to assign Fontes et al.'s early-season S. fistulosa galls to species (either to a new species or to an earlier generation of R. racemicola), but do assign these galls to the Rhopalomyia genus, provisionally as an undescribed species, "Rhopalomyia n.sp."

gallformers.org pages follow the treatment in Dorchin et al. (2009) in distinguishing three entities from this history:

• Schizomyia racemicola - the onion-shaped galls with red-orange larvae
• Rhopalomyia racemicola - Gagné's hairy, late-season "bud galls that may be situated among florets" on S. fistulosa (and S. altissima, assuming these are indeed conspecific with Felt's entity)
• Rhopalomyia s-fistulosa-bud-cluster-gall - This page is meant for the early-season S. fistulosa galls described by Fontes et al. (1994) and Dorchin et al. (2009) as a new Rhopalomyia species.