Subgenus Charmosta Motschulsky, 1865
Charmosta Motschulsky, 1865: 310 (type: investigator Illiger, 1798)
The species of the subgenus Charmosta belong to the Calosoma that have the ligula of the endophallus sclerified ("Calosomes ongulés" sensu Jeannel, 1940). Jeannel (1940), considers Charmosta a distinct genus, and refers it to the phyletic line Castrida-Caminara, that, according to his hypothesis, originated from the ancient Afro-Brazilian plateau. In this phyletic line in most cases a basal seta is still present close to hind angles of the pronotum.
Caminara, Campalita, Charmosta and Ctenosta have the metaepisternum with fine and dense punctuation and occupy the African and Eurasian continent, thus differing from the American Castrida. Both Charmosta and Ctenosta do not have the basal seta of the pronotum, but Charmosta can be easily sorted out because it has small but noticeable basal angles, that instead are imperceptible in Ctenosta. The sculpture of the elytra is characterized by the doubling of tertiary intervals (as interpreted by Jeannel), or by the presence of 22 intervals instead of 16 (according to the terminology used by American authors). Two species: investigator and lugens, are included in this subgenus. Both are found in the Far East, but investigator comes up to eastern Europe.