Subgenus Callitropa Motschulsky, 1865

Callitropa Motschulsky, 1865: 300 (type externum Say, 1823)
Blaptosoma partim Géhin, 1876: 45 (type laeve Dejean, 1826)
Aulacopterum partim Géhin, 1885: 34 (type viridisulcatum Chaudoir, 1853)
Paracalosoma Breuning, 1927: 120 (type palmeri Horn, 1875)
Paratropa Lapouge, 1929: 3 (type macrum LeConte, 1853)

According to Jeannel (1940), Camedula and Callitropa, that occupy Central America and southern United States, belong to a single phyletic line and are phylogenetically related to South American Castrida from which they differ in the chaetotaxy and in particular for having lost the brush on the male's mesotibiae. In the same lineage would also have evoluted the species of wingless mountain Calosoma, collected in the sub genera Carabomimus and Calopachys, that are limited to Mexico.
Inside this phyletic line, the species belonging to the subgenus Callitropa are characterized by the pronotum with arcuate sides, well developed rear lobes, and widely rounded basal angles. The humerus of elytra is smooth, without teeth (except C. haydeni).
The subgenus Callitropa (which, according to Jeannel, was a distinct genus) includes winged, brachypterous and apterous species, living in United States and Mexico. The winged species are externum, macrum and protractum, that previously formed the subgenus Callitropa s. str. palmeri is a brachypterous species that is exclusive to Isla Guadalupe, off the coast of Baja California, and that was previously attributed to a separate subgenus (Paracalosoma). The apterous species, exclusive of Mexico, are: anthracinum, atrovirens, laeve, porosifrons, viridisulcatum, collected by Jeannel in the subgenus Blaptosoma, and haydeni that Jeannel included in Camedula because of the character of serrate elytral margin near the humerus.

Calosoma (Callitropa) anthracinum Dejean,1826
Calosoma (Callitropa) atrovirens Chaudoir, 1869
Calosoma (Callitropa) atrovirens subsp. atrovirens Chaudoir, 1869
Calosoma (Callitropa) atrovirens subsp. explanaticolle Bates, 1891
Calosoma (Callitropa) externum Say, 1823
Calosoma (Camedula) haydeni Horn, 1870
Calosoma (Camedula) haydeni subsp. haydeni Horn, 1870
Calosoma (Camedula) haydeni subsp. punctulicolle Bates, 1891
Calosoma (Callitropa) laeve Dejean, 1826
Calosoma (Callitropa) macrum LeConte, 1853
Calosoma (Callitropa) palmeri Horn, 1875
Calosoma (Callitropa) porosifrons Bates, 1891
Calosoma (Callitropa) protractum Le Conte, 1862
Calosoma (Callitropa) viridisulcatum Chaudoir, 1853

updated Mar. 22 2020