Taxon classification Animalia Coleoptera Histeridae

Exaesiopus torvus Reichardt, 1926 Figs 55, 56-63, 64-72

Exaesiopus torvus Reichardt 1926: 17; Mazur (1984): 101; (1997): 264; (2004): 92; (2011): 210.

Type locality.

Yanidarya, Kyzyl-Ordinskij Rayon, Kazakhstan.

Type material examined.

Holotype, ♀ side-mounted on a triangular point, with female genitalia extracted and glued to the subsequent label with female sign, with following labels: “♀” (printed); followed by circular golden label; followed by: "Yany - Darya / perovsk u / Kyzyl-Kum / 24.iv.[1]911" (hand-written); followed by: "Type / Exaesiopus / torvus m. / A. Reichardt det." (written-printed label); followed by: “Holotypus” (red label, printed) (ZIN).

Additional material examined.

Kazakhstan: 1 ♀, left bank of the river Ural, Saraichikovsk, 8.vi.1932, Lukyanovich leg.; 1 ♀ + 2 specs., left bank of Ural river, opposite of Saraychik, 8.vi.1932, Lukyanovich leg.; 1 ♂, western bank of Aral Sea, Komsomolsk na Ustyurte, 31.v.1978, G. Medvedev; 1 spec., W Kazakhstan obl. [=reg.], Bilj-Agach, 4.vii.1952, L. Arnoldi (in leaf litter). (all exs. ZIN); 1 spec., 1933-102, left bank of the Ural River, Saraychik, 8.vi.[19]32, Lyukanovich (BMNH). Uzbekistan: 1 ♀, Karakum, Khiva, 3.v.1978, leg. Olexa; 1 ♂, ibid, but 1.-5.v.1979 (both exs. TLAN); RUSSIA: 1 spec., Astrakhan Region, Krasniy Yar district, near Dosang vill., 8.v.2009, A. Kovalyov leg. (CAS); 1 spec., ibid, but 14 km NE Dosang vill., barkhan [=sand dune] Tuvayak, 23-24.iv.2008, M. Smirnov leg. (CAS).

Diagnostic description.

Body length: PEL: 2.15-2.575 mm; APW: 0.575-0.875 mm; PPW: 1.625-1.925 mm; EW: 1.75-2.125; EL: 1.375-1.625 mm. Body (Fig. 55) strongly convex, cuticle as in Exaesiopus grossipes, but without metallic tinge; legs, mouthparts and antennae dark yellow to light brown. Antennae as in Exaesiopus grossipes; sensory structures of the antennal club not examined. Mouthparts: labrum obscurely variolate, shallowly depressed medially; mentum as in Exaesiopus henoni; rest of the mouthparts similar to those of Exaesiopus grossipes; terminal labial and maxillary palpomeres truncate. Clypeus (Fig. 56) as in Exaesiopus grossipes, but rugulose-lacunose; frontal, supraorbital and postorbital striae (Fig. 57) as in Exaesiopus grossipes; frons rugose, with several irregularly shaped carinate transverse rugae or chevrons intermingled with sparse microscopic punctures. Pronotum: pronotal disc, except for irregularly-shaped impunctate (or weakly punctate) median part entirely covered with round dense punctation, forming transverse rugae and confluent laterally, punctation reaches lateral margins; rest of pronotum as in Exaesiopus grossipes .

Elytral humeri not particularly enlarged; inner subhumeral stria present only as a row of several punctures; elytral punctation variable, in most specimens reaching elytral base along fourth elytral interval, punctures often present in all elytral intervals, elytral flanks impunctate; punctures regular and deep, separated by about half to several times their own diameter. Propygidium (Fig. 58) and pygidium as in Exaesiopus grossipes, but covered with denser punctation. Prosternum: prosternal foveae (Fig. 59) weakly impressed; prosternal process otherwise similar to that of Exaesiopus grossipes . Disc of mesoventrite (Fig. 60) with scattered shallow punctures; intercoxal disc of metaventrite, lateral disc of metaventrite and metepisternum generally similar to those of Exaesiopus henoni . Intercoxal disc of first abdominal sternite as in Exaesiopus grossipes . Protibia (Fig. 61) more dilated than that of Exaesiopus grossipes; on outer margin with two widely-spaced low teeth, topped by large triangular denticle followed by two low rounded denticles imbedded in outer protibial margin; protibial spur inconspicuous (absent?) protibia otherwise similar to that of Exaesiopus grossipes . Mesotibia (Fig. 62) generally similar to that of Exaesiopus grossipes . Metatibia (Fig. 63) perhaps most triangularly dilated and thickened of all congeners; outer margin with approximately three widely-spaced tiny denticles; inner margin with a dense row of minuscule rounded denticles; no rows of denticles present between the two rows, surface rugulose-lacunose.

Male genitalia. Eighth (Figs 64-65) sternite apically asetose, with tiny vela; eighth tergite apically faintly inwardly arcuate medially; eighth sternite and tergite fused laterally (Fig. 66). Ninth tergite (Figs 67-68) apically almost straight; tenth tergite apically outwardly arcuate, basally only faintly inwardly arcuate. Spiculum gastrale (Figs 69-70) generally similar to that of Exaesiopus grossipes . Aedeagus (Figs 71-72) almost parallel-sided, apex with pseudopores, parameres fused along their apical half (approximately); aedeagus slightly curved ventrad from the lateral view (Fig. 72).

Differential diagnosis.

Generally the most punctate species of Exaesiopus, which can be confused only with densely punctate specimens of Exaesiopus grossipes from N Africa. It clearly differs from them by the punctation of pronotum as well as male genitalia (see also Key to species for details).

Biology.

Similar to that of other congeners - beetles are found in sand.

Distribution.

Kazakhstan; new to Uzbekistan and Russia.