Calosoma (Callistenia) latipenne Horn, 1870
Calosoma latipenne Horn, 1870: 70 (described from California, South Sierras; syntype in Museum of Comparative Zoology, Harvard University, Cambridge, Ma)
Calosoma arcuata Casey, 1897: 343 (described from Arizona; syntype in National Museum of Natural History, Washington)
Callisthenes tularensis Casey, 1913: 68 (described from Tulare Co., California; syntype in National Museum of Natural History, Washington)
Callisthenes opimus Casey 1913: 69 (described from Kern Co., California; syntype in National Museum of Natural History, Washington)
Calosoma (Callisthenes) subaeneum latipenne Breuning, 1928: 81
Calosoma (Callisthenes) subaeneum opimum Breuning, 1928: 81
Callisthenes (Callistenia) subaenea latipennis Lapouge, 1932: 378
Callisthenes (Callistenia) subaenea opima Lapouge, 1932: 378
Microcallisthenes (Callistenia) subaeneus latipennis Jeannel, 1940: 173
Microcallisthenes (Callistenia) subaeneus opimus Jeannel, 1940: 173
Callisthenes (Microcallisthenes) latipennis Gidaspow, 1959: 306
Callisthenes (Callistenia) latipennis Erwin, 2007: 77
Length 14-18 mm. latipenne, as subaeneum, is characterized by a transverse pronotum with an almost smooth disk and roughness limited to the sides and to the rear part, its posterior lobes are broadly rounded not projecting from the base.
Compared to subaeneum, latipenne can be distinguished because it is generally slightly smaller in size and has more rounded and shorter elytra. Moreover, according to Gidaspow (1959) it has also a more elongate penis.
The sculpture of the elytra consists in striae identified by rows of shallow punctures. The intervals are flat and smooth, or very weakly incised by transverse wrinkles. The foveae on the primary intervals are small and barely visible. The upper body is black with faint greenish blue reflections.
latipenne was first considered by Breuning, togheter with opimum, as subspecies of subaeneum, followed on this by Jeannel (1940:173), who, we have to remember, did not knew the species. Gidaspow (1959), for her part, has re-evaluated latipenne as a good species and considered opimum as a synonym.
All the recent data confirm that latipenne is limited to California, but, according to Burgess and Collins (1917), it occurs also in Nevada (Reno), and Callisthenes arcuatus, that also should be a synonym, was described from Arizona.
Examined specimens and literature’s data
United States. California: Kern County (EM), Bakersfield (AMNH, SB), Mojave (EM); Fort Tejon State Park (AMNH), Los Angeles County: Lancaster, Antelope Valley, Madera Co. (Breuning 1928b: 83) Fresno Co., Tulare Co., San Bernardino Co. (Gidaspow 1959: 307), San Benito county (UASM).
Notes: Brachypterous. It inhabits lowland to upland from 100 to 1300m of altitude on sandy soil with scarce vegetation. Adults can be found from January to July (Erwin, 2007: 82).
United States: California Bakersfield 20. III. 26
United States: California, Mojave, (coll Migliaccio)