Lomechusoides chekanovskiyi Jászay, Hlaváč & Baňař, 2023

Jászay, Tomáš, Hlaváč, Peter & Baňař, Petr, 2023, A taxonomic revision of the myrmecophilous genus Lomechusoides Tottenham, 1939 (Coleoptera: Staphylinidae: Aleocharinae). Part II. The revision of the strumosus species group, Zootaxa 5343 (6), pp. 539-593 : 544-546

Lomechusoides chekanovskiyi Jászay, Hlaváč & Baňař sp. nov.

Figs 1–7

Etymology. The species is named after the collector of the new species Alexander Lavrentyevich Chekanovskiy, geologist and pioneer explorer of North Central Siberia who assembled impressive geological, botanical, and entomological collections in the second half of 19 th century.

Material studied. HOLOTYPE, ♁: RUSSIA: (h) бл. устьЯ НиЖн. Тунгуски Енис. г. А. Чекановскiй 26.8.73 [=bl. ust´ya Nizhn.Tunguski Enis. g. A. Chekanovskiy 26.8.73 = near estuary of Nizhnoj Tunguzki river , Yenis [eyskaya]. g[uberniya]. A. Chekanovskiy leg. 26.8.73] / (h) 59218. / red label (p) HOLOTYPE ♁ Lomechusoides chekanovskiyi sp. nov., T. Jászay, P. Hlaváč & P. Baňař det., 2021 ( ZIN) . PARATYPES, 1 ♁: same data as holotype ( PCPB). 2♁♁, 1♀: (h) 61560 / (h) 61562 / (h) 61565/(h) мы(ы-illegible) сто обы(ы-illegible)да 26 VIII.73 А. Чекановскiй [=m´sto ob´da, A. Chekanovskiy]/ green label (p) Inst. St. Petersbrg / all paratypes are bearing printed red label : PARATYPE ♁ or ♀ Lomechusoides chekanovskiyi sp. nov., T. Jászay, P. Hlaváč & P. Baňař det., 2021 ( ZIN) .

Description. Body light reddish-brown ( Fig. 1 ) except clypeus, labrum, antennae, boundless patch on vertex, boundless patches on supraorbital tubercles, boundless patches on lateral sides of head, anterior margin of visible tergites III–V, larger part of anterior margin of visible tergites IV–VII, anterior margin of visible sternite V and larger part of anterior margin of visible sternites VI–VII brown.

Head rectangular, shiny, slightly longer than wide, HW/HL: ♁ 0.88, ♀ 0.87, with deep, broad and round frontal median impression which is unevenly microsculptured by shallow punctures; disc of head microsculptured with finer punctures; dull; length of eyes ♁: 0.31x, ♀: 0.24x of length of head, eyes very slightly protuberant; temples very shortly narrowed behind eyes, straight and convergent posteriad.

Antennae long, scape ♁ 1.58x, ♀ 1.58x as long as wide and ♁ 2.37x, ♀ 2.37x as long as pedicel, pedicel ♁ 1.00x, ♀ 1.00x, III: ♁ 1.33x, ♀ 1.33x, IV: ♁ 1.00x, ♀ 1.00x, V: ♁ 1.22x, ♀ 1.20x as long as wide, antennomeres VI–VIII longly oval, terminal segment slender and acute, ♁ 1.36x, ♀ 1.31x as long as scape, relative length of antennomeres from base to apex: ♁: 19: 8: 12: 10: 11: 12: 12: 13: 12: 13: 26; ♀: 19: 8: 12: 10: 12: 13: 13: 13: 12: 13: 25.

Pronotum ( Fig. 2 ) slightly trapezoidal, ratio PW/PL: ♁ 1.50, ♀ 1.50, with short concave anterior margin, anterior corners obtuse, lateral sides in anterior half broadly rounded, in basal half concave and divergent posteriorly, posterior corners acute, bearing deep lateral microsculptured and sparsely punctate impressions, pronotal disc unevenly microsculptured, with sparse, uneven puncturation, tubercles slightly defined; median line well-defined, narrow; in lateral view, lateral margins in anterior half thick, narrowed anteriorly, in posterior half slightly narrower and slightly curved posteriad, lacking visible sharp edge; maximal pronotal width at posterior corners, here pronotum narrower than elytra at humeri; pronotum with reduced number of macrosetae, anterior margin with two macrosetae, lateral margins in posterior corners with one macroseta.

Anterior and lateral margins of metaventral process ( Fig. 5 ) concave with subparallel lateral lines, median line roof-like raised, posterior part in median line lacking lentil-like impression, metaventral process microsculptured and punctate; metaventral disc posteriad with shallow longitudinal impressions on sides of median line, metaventrite microsculptured and sparsely punctate with short setae not reaching margin of adjacent puncture.

Elytra finely punctate, ♁ 1.00x, ♀ 1.00x as long as pronotum, ratio EW/EL: ♁ 1.83, ♀ 1.83; with about three macrosetae in anterior part, humeral part lacking macroseate, distance between punctures on disc about twice to three times longer than diameter of puncture.

Abdomen with visible tergite II sparsely punctate and setaceous, visible tergites III–V with sparse puncturation and setation only on posterior margin, visible tergites VI–VII very sparsely and finely punctate at posterior and lateral margins, at base lacking puncturation, visible tergites II–VII unevenly microsculptured.

Aedeagus ( Figs 3–4 ) with median lobe slender, apical lobe tube-like, distinctly shorter than basal bulb, apex of median lobe short and sharp, with numerous pseudopores, from lateral view ventral side convex, apex sharp-shaped, lateral sides of anterior part of median lobe in ventral view subparallel or slightly convergent. Apex of parameres slightly divergent ( Fig. 6 ), hook-shaped and bent backwards, apex with about 4 setae, with scarce pseudopores lacking minute microsetae.

Spermatheca ( Fig. 7 ) with apical part 1.75x as long as basal part and 1.37x as wide as basal extended part, 2.86x as long as wide, apical part of spermatheca curved, in middle angustate and apex acuminous, linkage arm between apical and basal part the same thickness.

Measurements. (♁, Holotype): TL 5.05 mm; FB 2.50 mm; HL 0.80 mm; HW 0.70 mm; antennal length 2.25 mm; PL 0.90 mm; PW 1.35 mm; EL 0.90 mm; EW 1.65 mm; FTL 0.90 mm; MTL 1.00 mm; HTL 1.35 mm. (♀, Paratype): TL 4.65 mm; FB 2.50 mm; HL 0.82 mm; HW 0.72 mm; antennal length 2.45 mm; PL 0.90 mm; PW 1.35 mm; EL 0.90 mm; EW 1.65 mm; FTL 0.90 mm; MTL 1.10 mm; HTL 1.35 mm.

Differential diagnosis. L. chekanovskiyi is most similar to L. drobovi and L. poppiusi . From L. drobovi it differs by maximal pronotal width, by L. chekanovskiyi is at posterior corners, while by L. drobovi is before posterior corners, by the lack of an impression on the metaventral process, and by the shape of the spermatheca where the apical part is curved, constricted in middle and apex is pointed. From L. poppiusi it differs by the bicoloured head, from L. inflatiformis and L. inflatus by the lighter and unicoloured pronotum.

Host ant. Unknown.

Distribution. Russia (Krasnoyarsk territory).

Figures

FIGURES 1–7. Lomechusoides chekanovskiyi sp. nov. 1, male paratype, dorsal habitus; 2–6, male holotype. 2, pronotum in dorsal view (L: 0.90 mm, W: 1.35 mm); 3, aedeagus, lateral view; 4, aedeagus, ventral view; 5, metaventral process; 6, apex of paramere; 7, female paratype, spermatheca. Scale bars in mm.