Overview
The beetle family Glaresidae is comprised of one genus, Glaresis, that is found on all major continents except Australia. The family includes about 50 species worldwide, most of which inhabit arid and sandy regions. Members of the family are small (2.5-6.0 mm long) and light brown to dark brown. Adults are collected at lights. Larvae and biology of species in the family are not known.

Description
Length 2.5-6.0 mm. Shape oblong-oval, convex. Color tan to dark brown; dorsal surface with moderately dense, short setae. Head deflexed. Antennae 10-segmented with 3-segmented, opposable club; first segment of club often hollowed to receive segments 2 and 3; second and third segments of club tomentose. Eyes divided in half by canthus, with eucone ommatidia. Clypeus lacking tubercle or horn. Labrum truncate, projecting weakly beyond apex of clypeus. Mandibles toothed and projecting weakly beyond apex of clypeus; maxillae with 4-segmented palpi; labium with 4-segmented palpi. Pronotum short, broad, convex. Elytra convex with 10 distinct costae, intercostae with or without distinct punctures. Pygidium concealed by elytra. Scutellum exposed. Legs with coxae transverse; protibia fossorial, outer margin toothed, apex with one spur; meso- and metatibia with 2 apical spurs; spurs mesad, adjacent (not separated by basal metatarsal segment); metafemora and metatibiae enlarged to cover abdomen in retracted position; tarsi 5-5-5; claws equal in size, simple; empodium absent. Abdomen with 5 free sternites; 8 functional abdominal spiracles situated in pleural membrane. Wings well developed, M-Cu loop present, without apical detached veins. Male genitalia trilobed. References: Cooper 1983; Scholtz 1990; Semenov-Tian-Shanskii and Medvedev 1932. Key to species of United States and Canada: Gordon 1970; Warner 1995.

Classification Status
The genus Glaresis was traditionally placed in the family Trogidae (or the subfamily Troginae in the family Scarabaeidae) based on the trilobed male genitalia and five visible abdominal sternites. Glaresis has long been compared with primitive scarabaeoids (Ochodaeinae, Geotrupidae, Lucanidae, Hybosorinae) based on shared primitive characters. Glaresis shares no demonstratable, derived characters with any group and, as such, the family Glaresidae was created for the genus Glaresis (Scholtz et al. 1987). Based on plesiomorphic characters and comparison with "primitive" scarabaeoid groups, Scholtz et al. (1994) argued that the Glaresidae is the most primitive living scarabaeoid and that the Glaresidae is the sister group to all other Scarabaeoidea.

Distribution
About 50 species are distributed on all major continents except Australia (Scholtz 1982).

New World Genus of Glaresidae
Glaresis Erichson 1848

Ecology
Adults are found in dry, sandy areas and are attracted to lights. Adults stridulate weakly when handled (Scholtz et al. 1987). Based on the form of the lacinia, Scholtz et al. (1987) hypothesized that Glaresis species feed on subterranean fungi. Efforts to establish a laboratory culture from adults have not been successful (Scholtz et al. 1987).

Larvae
Immatures are not known but are probably of the scarabaeoid form.

References Cited
COOPER, J. B. 1983. A review of the Nearctic genera of the family Scarabaeidae (exclusive of the subfamilies Scarabaeinae and Geotrupinae) (Coleoptera), with an evaluation of computer generated keys. Doctoral Thesis, Department of Biology, Carleton University, Ottawa, Ontario, Canada. 1121 pp.

GORDON, R. D. 1970. A review of the genus Glaresis in the United States and Canada (Coleoptera: Scarabaeidae). Transactions of the American Entomological Society 96: 499-517.

SCHOLTZ, C. H. 1982. Catalogue of the world Trogidae (Coleoptera: Scarabaeoidea). Republic of South Africa, Department of Agriculture and Fisheries, Entomology Memoire 54: 1-27.

SCHOLTZ, C. H. 1990. Phylogenetic trends in the Scarabaeoidea (Coleoptera). Journal of Natural History 24: 1027-1066.

SCHOLTZ, C. H., D. J. BROWNE, and J. KUKALOVÁ-PECK 1994. Glaresidae, archeopteryx of the Scarabaeoidea (Coleoptera). Systematic Entomology 19: 259-277.

SCHOLTZ, C. H., D. D'HOTMAN, and A. NEL. 1987. Glaresidae, a new family of Scarabaeiodea (Coleoptera) to accomodate the genus Glaresis Erichson. Systematic Entomology 12: 345-354.

SEMENOV-TIAN-SHANSKII, A. and S. MEDVEDEV. 1932. Revisio synoptica specierum palaearcticarum novae tribus Glaresini (Coleoptera: Scarabaeidae). Societe Entomologie Français (Livre Centenaire), p. 337-342.

WARNER, W. B. 1995. Two new Glaresis from the desert Southwest, with notes on the identity of Glaresis mendica Horn (Coleoptera: Scarabaeidae: Glaresinae). Insecta Mundi 9: 267-271.