Information: Glaresis rufa was described by Erichson in 1848.
Adults of Glaresis rufa measure approximately 3-3.5 mm in body length. The body is compact, broadly oval, and dorsoventrally flattened, with a reddish-brown to rust-colored integument. The head is partially retracted into the anterior margin of the pronotum; the clypeus is short, anteriorly truncate, and finely microsculptured. The antennae are 10-segmented with a distinct, loosely articulated 3-segmented club (clava), slightly more prominent in males. The mandibles are well developed, asymmetrical, and robust.
The pronotum is subquadrate, about as long as wide, with rounded lateral margins and densely punctate surface; it is moderately convex. The elytra cover the entire abdomen and are coarsely striate-punctate, with distinct longitudinal costae and irregular grooves; epipleura are absent or indistinct. The scutellum is small, triangular, and only partially visible between the elytral bases.
The legs are fossorial, adapted for digging, particularly the forelegs; the protibiae are broadened and laterally dentate, terminating in strong apical spurs. Tarsi are 5-segmented (pentamerous), ending in simple ungues (claws).
The abdomen consists of six visible sternites, finely punctate ventrally. The pygidium is partially concealed beneath the elytra.
Sexual dimorphism is minimal; males may show slight modifications in antennal proportions or subtle differences in the terminal abdominal segments.
Body length: 3 - 3.5 mm
Peak activity: June - August (depends on region)
Remarks: Glaresis rufa is a psammophilous beetle species with fossorial adaptations, exhibiting predominantly crepuscular to nocturnal activity patterns. Adults are active primarily during warm evenings in late spring and summer months, often observed flying at dusk. Their biology remains poorly understood, particularly regarding the larval stages, which have not been conclusively described for any species within the family Glaresidae. It is presumed that the larvae develop in sandy substrates, possibly feeding on organic detritus or associated microbial communities. Adults are believed to be non-feeding or saprophagous, although direct feeding observations are lacking.
The species exhibits morphological and behavioral adaptations for life in xeric, sandy habitats, including a robust body, fossorial forelegs, and cryptic coloration. These traits suggest a predominantly endogeic lifestyle, with much of the life cycle occurring beneath the soil surface.
Glaresis rufa occurs in dry, open habitats with loose, sandy or sandy-loamy soils. It is typically associated with steppe-like environments, inland dunes, sandy grasslands, and dry riverbeds, often in areas with sparse vegetation. The species is highly specialized in its habitat requirements and sensitive to habitat disturbance, including afforestation, soil compaction, and urban development.
Its distribution is limited to parts of southern and central Europe, extending into western Asia. Within its range, populations are often fragmented and localized. In Central Europe, including the Czech Republic, the species is considered very rare and is included among regionally endangered or critically endangered invertebrates. The occurrence is typically restricted to isolated relict sites that provide suitable microhabitat conditions.
Distribution: Azerbaijan, Austria, Bulgaria, Czech Republic, China, Greece, Hungary, Kazakhstan, Poland, Romania, Slovakia, Serbia, Russia, Ukraine
Zoogeographic region: Palearctic
Taxonomic classification:
Material examined (& observation):
Our observation period: Jul ~ August
Sampling Methods: Attracted to light trap 
Slovakia
