.......Arctodium vulpinum (Erichson, 1835)
.......Syn. Cratoscelis vulpina Erichson, 1835
.......Syn. Cratoscelis aterrima Blanchard, 1850
.......Syn. Cratoscelis gayana Blanchard, 1850
.......Syn. Cratoscelis villosa Blanchard, 1850
.......Syn. Cratoscelis striolata Redtenbacher, 1868

Arctodium vulpinum (Erichson). Photo by Mary Liz Jameson.
Distribution of Arctodium vulpinum.

Description. Arctodium vulpinum is the most widespread and common species in the tribe Lichniini. It has a broad range of variation in morphological characters that make it a difficult species to diagnose. Arctodium vulpinum is, on average, the largest species of Lichniini, with males 8.0–12.0 mm long and females 8.5–11.7 mm long. Because there is some overlap in size (smaller specimens of A. vulpinum are as small as the largest specimens of A. discolor or A. planum), the best way to distinguish small specimens is by ruling out characters defining other species: A. vulpinum does not have a pale fringe of setae along the eye canthus as in A. planum, it does not have black setae on the legs and wide elytra giving it a square-like body form as in A. discolor, or it is not less than 6.5 mm long as in A. mahdii.

Remarks. In Blanchard’s (1850) description of Cratoscelis aterrima, he differentiated the species from others in the genus on the basis of the black color on all parts of the body. However, this species is based on a black color morph found in females of A. vulpinum. Aside from its black color, C. aterrima shares all other characters with A. vulpinum and observations of the more common brown morph males mating with black female morphs on flowers were noted in Cajon del Maipo, Chile (Hawkins 2006). In collections, series of A. vulpinum contain approximately one female black morph out of every eight female specimens collected. Although black color morphs have not been named as a subspecies in any publication, many collections have specimens labeled as C. vulpina aterrima. Because the black morphs do not constitute an isolated subdivision of A. vulpinum but rather are found throughout the populations as a phenotypic variant, they should not be considered a subspecies.

Distribution. Widespread in Central Chile from Region IV (Coquimbo) to Region IX (La Araucania).

Phenology. October through February with most known specimens being collected in late November or early December.

References:
Blanchard, C.É. (1850). Ordre des Coléoptères, pp. 51–62. In, Milne-Edwards, H., C. É. Blanchard, and H. Lucas (eds.), Museum d’Histoire Naturelle de Paris. Catalogue de la Collection Entomologique. Classe des Insectes, Ordre des Coléoptères. Vol. 1, Part 1, Gide & Baudry, Paris, 128 pp.

Hawkins, S. J. 2006. Revision of the Chilean tribe Lichniini Burmeister, 1844 (Coleoptera: Scarabaeidae: Melolonthinae). Zootaxa 1266: 1-63.