Cosmodiscus Sloane, 1907

Kipling, Will, 2020, Phylogeny and classification of the genus-group taxa of Loxandrina (Coleoptera, Carabidae, Abacetini), Deutsche Entomologische Zeitschrift 67 (2), pp. 151-182 : 151

Genus Cosmodiscus Sloane, 1907

Type species.

Cosmodiscus rubripictus Sloane, 1907: 372, by monotypy.

Selected literature.

Key to New Guinea species ( Darlington 1962), discussion of systematics and description of new species ( Straneo 1940, 1983).

Described species and range.

Eight species that cover a range from India, to Japan, New Guinea, and Australia.

Adult characteristics.

Species are medium to small sized, 5-9 mm, rather broad bodied beetles with very prominent eyes and sharply curved mandibles. In general they are reminiscent of some Drimostomatini taxa but do not share the characteristic rotated, right side up aedeagus found in that tribe ( Straneo 1942).

Life history notes.

In leaf-litter on the ground in New Guinea rainforests ( Darlington 1962, p.514) and taken at mercury vapor lights (EMEC specimens).

Discussion.

While Cosmodiscus is clearly within Abacetini there is no evidence that it is a member of Loxandrina . Moore (1965, p.9 in key) included this genus in the loxandrine series and this position was maintained by Allen and Ball (1980). Allen (1982, p. 403) removed the genus from the series based on a "preliminary study" but did not discuss his evidence for this decision or suggest an alternative placement. In Straneo’s (1940, 1983) discussion on the systematic position of Cosmodiscus he notes that the only character of distinction separating this genus from Aristopus LaFerté-Sénectère, 1853 is the lack of the dorsal elytral setigerous puncture such as is found in all Aristopus species. He concludes that Cosmodiscus is allied with Aristopus and those two genera with Metaxys Chaudoir, 1857 and Cyrtomoscelis Chaudoir, 1874. Based on my study of these genera, Cosmodiscus probably is congeneric with Aristopus but a formal synonymy cannot be established until a comprehensive review the genera of Abacetina is done for these taxa and other African and Oriental region groups, e.g., Inkosa Péringuey, 1926, Metabacetus , Mateuellus Deuve, 1990. All of these genera are very likely closely related within Abacetini .