Glaresis Erichson, 1848

Gordon, Robert D. & Hanley, Guy A., 2014, Systematic revision of American Glaresidae (Coleoptera: Scarabaeoidea), Insecta Mundi 2014 (333), pp. 1-91 : 4-6

Glaresis Erichson

Glaresis Erichson 1848: 925 ; Semenov-Tian-Shanskii and Mevedev 1932: 337; Pardo Alcaide 1958: 161; Gordon 1970: 500; Scholtz 1983: 210 l; Ratcliffe and Paulsen 2008: 60. Type-species: Glaresis rufa Erichson 1848 , by monotypy.

Eoglaresis Semenov-Tian-Shanskii and Medvedev 1932: 337; Gordon 1970: 52 (as subgenus); Scholtz 1982: 17 (synonym of Glaresis Erichson ); Ratcliffe 1991: 131; Jameson 2002: 15. Type-species: Glaresis oxiana Semenov-Tian -Shanskii and Medvedev 1932, by subsequent designation.

Eremoglaresis Semenov-Tian-Shanskii and Medvedev 1932: 337 (as subgenus of Eoglaresis ); Martín- Piera and López-Colón 2000: 487 (as synonym of Glaresis Erichson ). Type- species: Eoglaresis beckeri ( Solsky 1870) , by original designation.

Afroglaresis Petrovitz 1968: 270 ; Scholtz et al.1987: 345-354 (as synonym of Glaresis ); Ratcliffe 1991: 131; Jameson 2002: 15. Type species: Afroglaresis obscura Petrovitz 1968 , by original designation and monotypy.

Description. Glaresidae with head usually somewhat tuberculate, sometimes with clypeus punctate; frons and vertex with varying degrees and type of microsculpture. Pronotum usually with shallow to deep foveae except in ecostata group. Elytra with striae flat, slightly convex, or strongly convex, striae lacking carinae or with variably developed carinae. Mesosternum with sparse, widely scattered, setose ridges in basal 1/2, or with dense ridges sometimes forming reticulate pattern over most of surface, ridges sometimes forming strong, supporting structure at base of mesocoxae. Mesotibia with 3-6 or more spines in posterolateral emargination. Trochanter with apical margin smooth, or with 1 or 2 teeth, or serrate with series of small teeth. Metafemur without apical flange, or with narrow or wide flange. Metatibia nearly smooth, without posteromedian projection, or with projection small, or with posteromedian projection highly developed, prominent; median ridge of tubercles nearly absent to well developed. Abdomen not sexually dimorphic except in some species of the phoenicis and mendica groups.

Remarks. Glaresis Erichson has traditionally been classified as a close relative of Trox Fabricius , and more recently both genera have been grouped together in the Trogidae . As discussed by Scholtz (1986) and Scholtz et al. (1987), this grouping of Glaresis and Trox has been the subject of considerable controversy among authors. Scholtz et al. (1987), after examining characters of Glaresis and comparing them with those of primitive Scarabaeoidea, concluded that Glaresis is near the base of ancestral stock from which scarabaeoids arose, and erected the monobasic family Glaresidae for the genus.

Genera have been split off the original Glaresis by authors, and there has been some disagreement in the literature as to whether they are valid genera, subgenera, or should be treated as synonyms. Zidek (2007) stated the situation well, and we quote: “Semenov & Medvedev (1932) restricted Glaresis to the type species ( G. rufa Erichson 1848 ) and established the genus Eoglaresis for all others, moreover introducing also the subgenus Eremoglaresis to accommodate Eoglaresis becker ( Solsky 1870) . They based the split on absence ( G. rufa ) vs. presence of a lateral prominence near the mandibular base; subemarginate and smooth ( G. rufa ) vs. convex and serrate anterior clypeal margin; presence ( G. rufa ) vs. absence of large, round impressions on the pronotal disc; narrower ( G. rufa ) vs. broader metatibia; longer ( G. rufa ) vs. shorter tarsi; and in the case of Eremoglaresis on the presence of a pair of frontal tubercles on the clypeus of E. beckeri . In 1932 there were merely 13 species known (seven Nearctic and six Palearctic), of which Semenov and Medvedev had at hand only G. beckeri , G. handlirschi , G. oxiana , G. rufa and two species they described as new ( E. porrecta , E. zarudniana ). The differences they observed thus appeared more clear-cut and significant than they do today. With the exception of Báguena (1959) and Paulian (1980), later authors regarded Eoglaresis as a subgenus or a synonym of Glaresis , because with increasing numbers of species the above criteria became untenable.”

Herein we consider all species as belonging to Glaresis , with Eoglaresis and Eremoglaresis as junior synonyms. The only other genus ascribed to the family was the African Afroglaresis Petrovitz , placed as a junior synonym of Glaresis by Scholtz et al.(1987).

Sequences of group and species taxa are based on character polarities as determined by Scholtz et al. (1986) and Zidek (2007). In general, some of the characters they consider primitive are: smooth body surface, smooth clypeal apex, pronotal surface lacking foveae, lateral mesotibial apical projection weak, posteromedian metatibial projection weak or lacking, and male genitalia with basal piece shorter than parameres. We attempt to follow their arrangement by placing the relatively smooth, weakly modified species of the ecostata group first, the roughly sculptured, highly modified species of the mendica group last, and apparently intermediate groups between. Within groups species are arranged based on observed shared characters. For example, within the mendica group 3 subgroups occur based primarily on structure of the metasternal groove. Those subgroups species sharing common characters are further clustered.

Species of Glaresis are nearly always collected in arid areas, primarily those with sand deposits. However, some species, usually in the mendica group, are found in habitats apparently lacking sand. Most of these sites yielded only a specimen or two, rarely an extensive series, therefore this group is the least well known.

Most known Glaresis species have been taken at light where they may be abundant, and several species are occasionally collected together on a given night. For example, J. Carr found 3 species together at a collection site near Hasty, Bent County, Colorado, and R. Gordon found 4 species in a single night of light trapping north of Sedona, Coconino Co., Arizona. Larvae are still unknown in spite of efforts to rear adults under laboratory conditions ( Baker 1968). We suspect that larvae are present deep in the substrate, and will be found at or near the interface of dry/wet soil (sand). Scholtz et al. (1987) hypothesized that Glaresis feeds on subterranean fungi. We assume that species of Glaresis are detritivores, most of them psammophilus, that use the same resource as psammophilus detritivores of the Aphodiini genus Flaviellus Gordon and Skelley , as well as other aphodiine scarabs.

Specimens from Mexico and Central America are rarely found in collections, hence the fauna of those regions is not adequately covered in this study. Certainly that fauna is more extensive than represented here.

Glaresis specimens examined are divisible into 5 groups as indicated in the following key.