Subgenus Chrysostigma Kirby, 1837

Chrysostigma Kirby, 1837: 19 (type: calidum Fabricius, 1775)
Tapinosthenes Kolbe, 1895: 57 (type: cancellatum Eschscholtz, 1833)
Lyperostenia Lapouge, 1927: 3 (type: triste LeConte, 1844 = affine Chaudoir, 1843)

Jeannel (1940) considered Chrysostigma, Microcallisthenes and Callisthenes as a result of a unique evolutionary line that, in his hypothesis, dates back to Asian Caminara and then spreaded to North America via the Arctic lands in the tertiary period. All the species pertaining to this evolutionary line should be identified by the glabrous elongated spots they have on the outer face of the articles of antennas from the fifth segment onwards and by the absence of brush on the middle tibiae of the males. All of them have setae on metatrochanter and lack the setae at the base of the pronotum.
Within this group of genres (or subgenres), and again according Jeannel, Callisthenes stands out because of its mentum without setae. On the contrary Chrysostigma and Microcallisthenes, have setae on the mentum. Moreover Chrysostigma differs from Microcallisthenes, because it has only a small, triangular, non-hypertrophic, ligule.
Gidaspow challenged the affinity of Chrysostigma with Microcallisthenes and Callisthenes, mainly because the presence of the non-pubescent band on the articles of antennas is not constant. This is true, even though this characteristic in Microcallisthenes and Callisthenes may vary from individual to individual. In any way, basing on these considerations, Gidaspow has put Callisthenes as a genre distinct (including Microcallisthenes and others, as subgenres) and has considered Chrysostigma, as a subgenre of Calosoma.
This approach was not accepted by Larochelle and Larivière (2003) that recognize the genus Calosoma only, neither by Erwin (2007), that treats Chrysostigma as a subgenus of Callistenes. On the contrary Obidov (2002), as did Kryzhanovskij (1962), shares the views of Gidaspow but stresses the elements linking Chrysostigma to Callisthenes, so as to conclude: " The species of the subgenus Chrysostigma probably represents the transitive forms between genus Callisthenes and genus Calosoma, but on the main characters the subgenus Chrysostigma are more closely related to genus Calosoma".
The more appropriate location of Chrysostigma in relationship with other subgenres therefore remains open. More recent studies (Su et alia, 2005:146) seem to confirm the affinity between Chrysostigma, Microcallisthes and Callistenes, although the same affinity seems to exist with Callitropa, and even though their differentiation, as estimated in these studies, is much more recent than assumed by Jeannel.
Chrysostigma includes winged species, with sculpture of the elytra obsolete or in which the intervals are of the same height and width ("homodyname" type of Jeannel), and species with underdeveloped wings or brachypterous, of "homodyname" type, in which all the intervals dissolve in granules or surface roughness (tepidum), or of "hétérodyname" type, in which the primary intervals are more raised and the others dissolved in granules (cancellatum).

Calosoma (Chrysostigma) affine Chaudoir, 1843
Calosoma (Chrysostigma) calidum (Fabricius, 1775)
Calosoma (Chrysostigma) cancellatum Eschscholtz, 1833
Calosoma (Chrysostigma) morrisonii Horn, 1885
Calosoma (Chrysostigma) obsoletum Say, 1823
Calosoma (Chrysostigma) semilaeve LeConte, 1852
Calosoma (Chrysostigma) simplex LeConte, 1878
Calosoma (Chrysostigma) tepidum LeConte, 1852

last review April 18 2019