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
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;
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.
About 50 species are distributed on all major continents except Australia (Scholtz
New World Genus of Glaresidae
Glaresis Erichson 1848
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).
Immatures are not known but are probably of the scarabaeoid form.
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.