Lomechusoides richteri 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 : 571-573

Lomechusoides richteri Jászay, Hlaváč & Baňař sp. nov.

Figs 94–101

Etymology. Named after the collector Richter, a person who has remained unknown to us.

Material studied. HOLOTYPE, ♁: RUSSIA: (p) Саратовск. р. Лес. Ин. С-хи М (h) в (probably Saratov Agriculture Institute ). Form. rufa 11.5.929. (p) Рихтер [Richter]. / red label (p) HOLOTYPE ♁ Lomechusoides richteri sp. nov., det. T. Jászay, P. Hlaváč & P. Baňař det., 2021 ( ZIN) . PARATYPE, 1♀: same data as for holotype, with printed red label : PARATYPE ♀ Lomechusoides richteri sp. nov., det. T. Jászay, P. Hlaváč & P. Baňař det., 2021 ( ZIN) .

Description. Body ( Fig. 94 ) light reddish-brown except labrum, pronotum, anterior margin of visible tergites II–IV, larger part of anterior margin of visible tergites V–VII, anterior margin and lateral part of visible sternites III–V, larger part of anterior margin of visible sternite VI–VII, metaventrite except its narrow posterior margin, epimeral and episternal sclerites brown.

Head rectanglular, longer than wide, HW/HL: ♁ 0.79, ♀ 0.87 with deep V-shaped frontal median impression which is evenly microsculptured with visible fine punctures, dull; disc of head evenly microsculptured and finely punctate, dull; length of eyes of both sexes 0.25x length of head; eyes slightly protuberant, temples behind eyes narrowed and lateral sides concave. Antennae short, scape ♁ 1.52x, ♀ 1.41x as long as wide and ♁ 2.36x, ♀ 2.40x as long as pedicel, pedicel ♁ 1.00x, ♀ 0.91x as wide as long, antennomeres III: ♁ 1.28x, ♀ 1.16x, IV: ♁ 1.00x, ♀ 1.07x and V: ♁ 1.16x, ♀ 1.25x as long as wide, terminal antennomere slender and acute, ♁ 1.15x, ♀ 1.25x as long as scape, relative length of antennomeres from base to apex: ♁: 26: 11: 16: 12: 14: 15: 15: 15: 14: 14: 30, ♀: 24: 10: 14: 14: 15: 16: 15: 15: 14: 14: 30.

Pronotum ( Fig. 95 ) slightly trapezoidal, ratio PW/PL: ♁ 1.68, ♀ 1.62, with slightly concave anterior margin, anterior corners obtuse, lateral sides in anterior third broadly rounded, in basal two thirds straight or slightly concave, diverging posteriad, basal corners rectangular, bearing microsculptured and unevenly sparsely distributed punctures, with broad, shallow lateral impressions, pronotal disc slightly more but finely microsculptured, sparcely, unevenly punctate, tubercles well-defined; median line well-defined; in lateral view lateral margins thick, narrowed anteriad, in posterior half gradually narrowed and broadly curved posteriad, lacking visible sharp edge; maximal width of pronotum shortly before posterior corners, here as wide as elytra at humeri; pronotum with macrosetae, anterior margin with about four macrosetae, lateral margins with about five to six macrosetae.

Anterior and lateral margins of metaventral process ( Fig. 98 ) concave, metaventral process in anterior part with lateral strongly convergent lines, anterior part with weakly-defined transversal elevation, anterolateral corners with triangle-shaped tubercles, median line lacking roof-like elevation, posterior part in median line with deep, lentil-like impression, metaventral process microsculptured and sparsely punctate; metaventral disc with broad, shallow longitudinal impressions and in posterior part with straight lines on lateral sides of median line, metaventrite microsculptured and densely punctate, with long setae exceeding margin of adjacent puncture.

Elytra finely punctate, elytra ♁ 0.98x, ♀ 0.91x length of pronotum, ratio EW/EL: ♁ 1.95, ♀ 1.95, anterior part with about ten and humeral part with about two macrosetae, distance between punctures on disc two to three times as long as diameter of puncture.

Abdomen with visible tergite II densely punctate and setaceous, tergites III–IV densely punctate and setaceous on posterior margin, anterior part with fine and sparse puncturation, visible tergite V with fine and sparse puncturation, posterior margin slightly less densely punctate, larger part of lateral sides of visible tergites VI–VII sparsely punctate, distance between punctures larger to diameter of puncture, visible tergites II–VII evenly microsculptured.

Aedeagus ( Figs 96–97 ) with robust median lobe, apical lobe tube-like, apical part shorter than basal bulb, apex acute with scattered pseudopores, from lateral view ventral side of apical part straight and sharply shaped, lateral sides of apical lobe in ventral view convergent apically. Ventral protuberance on basal bulb conical, 2.5x as long as wide. Apical lobe of parameres at apex subparallel-sided ( Fig. 99 ), hook-shaped and bent backwards, before apex slightly strangulated, apex with about four setae, with dense pseudopores, pseudopores lacking minute microsetae.

Spermatheca ( Fig. 100 ) with apical part moderately long, 1.15x as long as basal part and 1.13x (on widest part) wider than basal extended part and 3.60x as long as wide, apical part subparallel, curved, apical fourth slightly narrowed apically, apex rounded.

Measurements. (♁, Holotype): TL 5.45 mm; FL 3.17 mm; HL 1.10 mm; HW 0.87 mm; antennal length 3.00 mm; PL 1.07 mm; PW 1.80 mm; EL 1.05 mm; EW 2.05 mm; FTL 1.25 mm; MTL 1.55 mm; HTL 1.95 mm. (♀, Paratype): TL 5.25 mm; FL 3.00 mm; HL 1.00 mm; HW 0.87 mm; antennal length 2.85 mm; PL 1.20 mm; PW 1.95 mm; EL 1.10 mm; EW 2.15 mm; FTL 1.25 mm; MTL 1.50 mm; HTL 1.80 mm.

Differential diagnosis. L. richteri is separated from L. dlabolai and L. reitteri by the large, bicoloured body. From L. folgaricus , L. primoricus , L. strumosus and L. wellenii , it differs by the trapezoidal pronotum, and from L. penicillatus by shorter antennae. From L. zeyai and L. sibiricus , it differs by the presence of humeral macrosetae on elytra and by the lack of a sharp visible edge on the lateral margin of the pronotum in lateral view. From L. zerchei it differs by the 90 degree angled posterior corners of the pronotum, by the maximal pronotal width which is equal to the width of elytra at humeri. From L. rossii and L. terres , it differs by the wider and shallower, evenly microsculptured and punctate lateral impressions of the pronotum and by well-defined tubercles on the pronotal disc. From L. fallax , it differs by the uniformly microsculptured pronotum, which is lacking shiny spots. From the similar L. siculus , it differs by the slighter visible punctation, with thicker and shorter setae which do not reach the margin of the adjacent puncture on the frontal impression of the head, by shape of antennal segments IX–X, which are robust and cone-shaped as base and cylindrical at apex, and by the presence of triangle-shaped tubercles on anterolateral corners of the metaventral process. From similar L. dudkorum it is distinguished by the straight ventral side of apex of the median lobe of the aedeagus in the lateral view and by lateral sides convergent anteriorly in ventral view; apex of spermatheca is 3.56 x as long as wide and 1.15 x as long as its basal part, while at L. dudkorum in the ventral side the apical lobe is slightly convex and lateral sides in ventral view is slightly convergent anteriorly; apical part of spermatheca is 2.06 x as long as wide and 0.76 x as long as basal part.

Host ant. Unknown.

Distribution. Russia (Saratovsk district)

Figures

FIGURES 94–101. Lomechusoides richteri sp. nov. 94–99, 101, male holotype. 94, dorsal habitus; 95, pronotum in dorsal view (L: 1.07 mm, W: 1.80 mm); 96, aedeagus, lateral view; 97, aedeagus, ventral view; 98, metaventral process; 99, apex of paramere; 100, female paratype, spermatheca; 101, antennomeres IX–X. Scale bars in mm.