Calosoma (Castrida) fulgens Chaudoir, 1869

Length 25-30 mm. The pronotum of C. fulgens is evenly rounded (more so in males) and the elytral sculpture is characterized by very slightly convex intervals. The elytra are elongated, the hind angles of pronotum very small, almost obliterated, the metatrochanter of males has a strongly pointed tip, the upper body is metallic bright red or more rarely green bronzed.
The male of C. fulgens is easily distinguished from the ones of other species, in which the metatrochanter has also a pointed tip, because of the shape of pronotum and because of the apex of aedeagus which is decidedly elongated and strongly bent. In case of the female, where the metatrochanter is obtuse, it can be distinguished from the female of C. retusum that sometimes can be confused with it, taking into account the smallness of the hind angles of pronotum as well as the shape of the intervals of the elytra, that are less convex than in retusum.
The label of the holotype of C. fulgens shows no locality details, but the author in the description gives Paraguay as the origin of the specimen. However, C. fulgens would seem restricted to the north-western region of South America, and seems highly improbable the presence in Paraguay as indicated in the original description and in Uruguay at San Carlos on the atlantic coast (Gidaspow, 1963: 295). Moreover the quotes from Bolivia (Breuning, 1927: 197), and the ones from Chile and Brazil (Erwin, 2007: 93) need confirmation.
It is known with certainty from the north-western Peru, Colombia and the whole of Ecuador. however, the specimen observed in the main port of Galapagos Archipelago was certainly imported by passive transport on one of the many means that commute from the continent. Instead, more interesting is the recent find in Costa Rica. In this last case it could also possibly be an occasional visitor, though already Erwin (1991: 18), taking into account the characteristics of its habitat, considered possible that C. fulgens could expand its distribution area in Central America when the forests are cut away to to obtain space for agricultural purposes.

Examined specimens and literature’s data
Colombia. Huila: Gigante (SB), Cali (Baer, 1902: 83), Caldas dep., Norcasia, Reserva Natural Río Manso (Uribe & al., 2013)
Costarica. Limon (RS)
Ecuador. El Oro: Santa Rosa (www.inaturalist.org); Guayas: Pta Chapella (EM), Empalme, El Morro (www.inaturalist.org), Playas, Puerto El Morro (Campos, 1921: 30), Santiago de Guayaquil (MCZR, SB), Posorja (Campos, 1921: 30), Durán, Naranjal, Chanduy, Pasaje (Moret, 1986: 91); Santa Elena: Punta Santa Elena (Gidaspow, 1963: 295); Punta Blanca (www.inaturalist.org); Loja: Mangahurco (www.inaturalist.org); Los Ríos: Quevedo (Moret, 1986: 91); Manabí: Manabí (SB), Puerto López (Moret, 1986: 91), Pedernales, Jipijapa, Manta (www.inaturalist.org), Monte Cristi (SB), Puerto Cayo (TL), Sucre (TL); Esmeraldas: Atacames, Esmeraldas (Moret, 1986: 91); Pichincha: Quito (www.inaturalist.org); Zamora Chinchipe: Indanza (Moret, 1986: 91)
Galápagos Archipelago (Ecuador). San Cristobal (Chatam): Puerto Baquerizo Moreno (www.inaturalist.org/obs/150946538).
Peru. Cajamarca: Jaén (www.inaturalist.org); Tumbez: Grau, San Pedro de los Incas (Baer, 1902: 83)

Notes: Winged, diurnal and nocturnal, attracted to light at night. It prefers grasslands with sparse bushes, or tilled fields, it is more common in coastal area and has been observed preying on caterpillars of Lepidoptera Noctuidae. Captures of active individuals were noted from December to March (on the basis of the material examined) up to June (Moret, 1986: 92) and later from August to October (Erwin 2007: 93).

Calosoma (Castrida) fulgens ♂ Chaudoir, 1869 Paraguay (holotype) (Muséum National d'Histoire Naturelle, Paris)

Calosoma (Castrida) fulgens ♂ Chaudoir, 1869 Costarica: Limon (coll R. Sciaky) (photo Riccardo Sciaky)

Calosoma (Castrida) fulgens ♂ Chaudoir, 1869 Ecuador: Guayas, Pta Chapella, 10-15.1.91 (coll E. Migliaccio)

Calosoma (Castrida) fulgens ♀ Chaudoir, 1869 Ecuador: Manabi, 15.2.89