Calosoma (Chrysostigma) affine Chaudoir, 1843

Calosoma affine Chaudoir, 1843: 746 (described from Mexico, syntype in Muséum National d'Histoire Naturelle, Paris)
Calosoma triste LeConte, 1844: 201 (described from Missouri; syntype in Museum of Comparative Zoology, Harvard University, Cambridge, Ma)
Calosoma ampliator Bates, 1891: 223 (type: Mexico, Durango, Villa Lerdo; British Museum of Natural History, London)
Calosoma tristoides Fall, 1910: 92 (syntype: California, San Diego; Museum of Comparative Zoology, Harvard University, Cambridge, Ma)
Calosoma (Carabosoma) affine affine Breuning, 1928a: 108
Calosoma (Carabosoma) affine tristoides Breuning, 1928a: 108
Calosoma (Carabosoma) affine triste Breuning, 1928: 108
Callisthenes (Lyperostenia) tristis Lapouge, 1931: 382
Chrysostigma affine Jeannel, 1940: 169
Callisthenes (Chrysostigma) affinis Erwin, 2007: 74

Length 16-20 mm. Respect to C. semilaeve and C. simplex, that likewise have elytra more or less elongated with almost parallel sides and sculpture just consisting of punctate striae and flat intervals, C. affine is easily characterized by the metallic green foveae on the primary intervals that stand out on the elytral surface. Furthermore, the humerus of its elytra is with a strong serration that is more evident than in the other species of the subgenus.
Breuning (1926b: 174), reviewing the description of Bates (1891: 223) of Calosoma ampliator, but apparently without knowing the type, considered it as a synonym of C. affine, followed in this by Jeannel (1940: 169). Later Gidaspow (1959: 267) reevaluated C. ampliator but, in our view, erroneously identifying it with specimens that should be attributed to another species of a different sub-genre: Calosoma (Camedula) peregrinator.
According Gidaspow (1959) C. ampliator should live in Mexico with C. affine and would spread up to Panama (Chiriqui), according to a quotation from Lapouge (1927: 7) that, however, has been called into question by all subsequent authors who have dealt with the matter. Anyway, C. affine is surely present in southwestern United States and in northern and central Mexico.

Examined specimens and literature’s data
Mexico. Mexico (type MNHN); Baixa California: La Paz (Jeannel, 1940: 170); Chihuahua: Santa Barbara, Salaices (Gidaspow, 1959: 269); Durango: Villa Lerdo (= Ciudad Lerdo) (holotype, BMNH; sub C. triste, NMP); Hidalgo: Pachuca (Breuning, 1928a: 109); Mexico city: Villa de Guadalupe (Gidaspow, 1959: 269); Nuevo Leon: Apodaca, Monterrey (Gidaspow, 1959: 269); Oaxaca: Zaachila (Gidaspow, 1959: 269); Tamaulipas: Valle del Maiz (Gidaspow, 1959: 269).
United States. Arizona: Apache County, Yavapai County, (Gidaspow, 1959: 269) Maricopa County (, Santa Cruz county, Cochise County (UASM); California: Orange County, San Joaquim County, Imperial County (Gidaspow, 1959: 269), San Diego (Breuning, 1928a: 109); Colorado: Fort Collins (Breuning, 1928a: 110), Denver County, Baca County (Gidaspow, 1959: 269); Kansas: Kearny county (UASM); Sherman County, Reno County, Atchison County, Fort Riley County, Kiowa County (Gidaspow, 1959: 269); New Mexico: Water Canyon (sub C. triste Snow,1881: 39), Dona Ana County (Gidaspow, 1959: 269); Oklaoma: Cleveland County (Gidaspow, 1959: 269); Texas: Presidio county (UASM); El Paso County, Live Oak County, Travis County, Nueces County, Hidalgo County (; Denton County (SB), Taylor County (SB), Brewster County, Starr County (Gidaspow, 1959: 269).

Notes:Winged, diurnal and nocturnal, sometime swarming in large number of individuals. It can be found in lowlands and mountains up to 2400m altitude. Adults lives on open ground as pastures and tilled fields (Larochelle & Larivière, 2003: 175) and has been cited as a predator of cutworm (caterpillar of Noctuidae family) that causes damage to cotton (Hake, 1996: 264). It is active from April to October, according to Erwin (2007: 74-75), or up to November, according to data of examined material.

Calosoma (Chrysostigma) affine ♀ Chaudoir, 1843
Mexico (type)
(Muséum National d'Histoire Naturelle, Paris)

Calosoma (Chrysostigma) affine ♂ Chaudoir, 1843
(syntype of Calosoma triste LeConte, 1844)
Nebraska, Kansas, N.Dak, S.Dak, Okla, Colo, Wyo, Mont
(Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA)
Calosoma (Chrysostigma) affine ♂ Chaudoir, 1843
United States: Texas, Denton county,
Justin, 25.X.1976, Gaumer and Murray lgt.
Calosoma (Chrysostigma) affine ♀ Chaudoir, 1843
United States: Texas, Taylor county,
26.nov.66, McWorther