Hille Ris Lambers (1960) erected the genus Toxopterella for his new species, canadensis, collected in Ontario and New Brunswick from Crataegus. At that time he had seen only the alate form of the species from Sorbus described herein, not the fundatrix, which is almost indistinguishable from the fundatrix of Toxopterella canadensis H.R.L. Because of the similarities in the fundatrices and because of the unique characters that they have in common in this morph, we place the aphid from Sorbus in the genus Toxopterella H.R.L., 1960. But the alatae of the two species are distinctly different and we therefore place this species from Sorbus in a new subgenus Sorbobium.