Lomechusoides dudkorum 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 : 561-563

Lomechusoides dudkorum Jászay, Hlaváč & Baňař sp. nov.

Figs 57–67

Etymology. The species is dedicated to the collectors of the type specimens, Russian entomologists Andrey and Roman Dudko, Institute of Animal Systematics and Ecology, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.

Material studied. HOLOTYPE, ♁: RUSSIA: (p) 6 км к югу от г. Тюмени [6km k yugu ot g. Tyumeni (= 6 km to the south from town Tyumen)], A. et. R. Dudko leg., (h) 3.04.1995 / red label (p) HOLOTYPE ♁ Lomechusoides dudkorum sp. nov., det. T. Jászay, P. Hlaváč & P. Baňař det., 2021 ( PCAS) . PARATYPE, 2 ♀♀: RUSSIA: (p) 6 км к югу от г. Тюмени [= 6 km to the south from town Tyumen], A. et. R. Dudko leg., (h) 3.04.1995 ( PCAS) . 1♁, 1♀: (p) Urengai [Urengoy]— Gory, Katav : Ural, 1916. Jureček. ( NMPC) . 1♀: (p) Sibir. or. Ussuri, Vladivostok , Dr. Jureček 1919. ( NMPC) . All paratypes are bearing the following printed red label: PARATYPE ♁ or ♀ Lomechusoides dudkorum sp. nov., det. T. Jászay, P. Hlaváč & P. Baňař det., 2021.

Description. Body light reddish-brown ( Fig. 57 ) except unbounded patch on clypeus, labrum, antennae, narrow anterior margin of visible tergites II–IV, anterior margin of visible tergite V, larger part of anterior margin of visible tergite VI–VII, lateral part of visible sternites III–V, posterior margin of visible sternite V, larger part of anterior margin of visible sternite VI, anterior margin of visible sternite VII, metaventrite except anterior part of metaventral process, episternal and epimeral sclerites brown.

Head rectangular, slightly longer than wide HW/HL: ♁ 0.78, ♀ 0.84, with deep, narrow U-shaped frontal median impression which is microsculptured and finely punctate, dull; disc of head microsculptured, finely and weakly punctate, dull; length of eyes ♁ 0.22x, ♀ 0.23x of length of head; eyes slightly protuberant, behind eyes temples narrowed, in basal half slightly concave.

Antennae long, scape ♁ 1.47x, ♀ 1.29x as long as wide and ♁ 2.27x, ♀ 2.00x as long as pedicel, pedicel ♁ 0.98x, ♀ 0.91x, antennomere III: ♁ 1.38x, ♀ 1.23x, IV: ♁ 1.07x, ♀ 1.03x and V: ♁ 1.20x, ♀ 1.15x as long as wide, antennomeres VI–IX oval elongate, X cone-shaped, terminal segment slender and acute, ♁ 1.16x, ♀ 1.40x as long as scape, relative length of antennomeres from base to apex: ♁: 25: 11: 18: 14: 15: 16: 16: 16: 15: 15: 29; ♀: 22: 11: 16: 14: 15: 16: 16: 16: 15: 15: 31.

Pronotum ( Fig. 58 ) trapezoidal, ratio PW/PL: ♁ 1.73, ♀ 1.53, with concave anterior margin, anterior corners obtuse, anterior half of lateral sides rounded, before middle obtusely angled, sligthly convex and divergent posteriad, narrowed shortly before posterior corners, posterior corners obtusangular or slightly rectangular, bearing deep lateral microsculptured and sparcely punctate impressions, pronotal disc microsculptured, sparsely and unevenly punctate, tubercles well-defined; median line well-defined, narrow; in lateral view lateral margins thick, slightly narrowed anteriad, in posterior half equally thinned 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 five macrosetae, lateral margins with about six macrosetae.

Anterior and lateral margins of metaventral process ( Fig. 61 ) slightly concave, in anterior part with lateral lines, convergent anteriorly and connected together, posterior part in median line with well-defined round shallow lentil-like impression, metaventral process microsculptured and sparcely punctate; metaventral disc with divergent lines and shallow longitudinal impressions on both sides of median line, metaventrite microsculptured and unevenly but densely punctate, discal setae long, setae reaching or slightly exceeding margin of adjacent puncture, (♀: discal setae long, setae clearly exceeding margin of adjacent puncture).

Elytra finely punctate, elytra ♁ 1.00x, ♀ 1.00x as long as pronotum, ratio EW/EL: ♁ 1.88, ♀ 1.95, with about eight–nine macrosetae in anterior part and about two macrosetae in humeral part, distance between punctures on disc of elytra two to three times longer than diameter of puncture.

Abdomen with visible tergite II unevenly densely punctate and setaceous, posterior margin of visible tergite III–IV finely punctate and setaceous, anterior margin with fine puntures, posterior margin of visible tergites V–VII with sparse punctures, lateral parts of visible tergite VII with large and shallow punctures, visible tergites II–VII microsculptured, weakly microsculptured only on lateral part of visible tergites III–V.

Aedeagus ( Figs 59–60 ) with median lobe and basal bulb robust, apical lobe tube-like, apical part long and sharp with poorly scattered pseudopores, ventral side in lateral view slightly convex, apex sharp, lateral sides of apical lobe in ventral view slightly convergent anteriorly. Apical lobe of parameres convergent apically ( Fig. 62 ), hook-shaped and bent backwards, before apex slightly constricted, apex with about three setae and with few pseudopores, lacking minute microsetae.

Spermatheca ( Fig. 64 ) with apical part 0.78x as long as basal part and 1.45x (on widest part) broader than basal extended part and 1.93x as long as wide, apical part short and subparallel, apex rounded. Variability of spermatheca can bee seen on Figs 64–67 .

Measurements. (♁, Holotype): TL 6.10 mm; FB 3.10 mm; HL 1.15 mm; HW 0.90 mm; eye 0.25 mm; antennal length 3.05 mm; PL 1.15 mm; PW 2.00 mm; EL 1.15 mm; EW 2.17 mm; FTL 1.25 mm; MTL 1.60 mm; HTL 1.90 mm. (♀, Paratype from the same locality as Holotype): TL 6.50 mm; FB 3.50 mm; HL 1.07 mm; HW 0.90 mm; eye 0.35 mm; antennal length 3.00 mm; PL 1.30 mm; PW 2.00 mm; EL 1.15 mm; EW 2.25 mm; FTL 1.25 mm; MTL 1.70 mm; HTL 2.00 mm.

Differential diagnosis. L. dudkorum is separated from L. folgaricus , L. primoricus , L. strumosus and L. wellenii , by the trapezoidal pronotum. From L. fallax it differs by evenly microsculptured disc and by lacking shiny spots on the pronotum and from L. penicillatus by shorter antennomeres. From L. dlabolai and L. reitteri its distinguished by the larger size and the bicoloured body. From L. rossii and L. terres , it differs by the wide and shallow, evenly punctate lateral impressions on the pronotum and by the well-defined tubercles on the pronotal disc. From L. siculus by the cylindrical apical part and cone-shaped basal part of the antennomere X, by thick and short setae on the frontal impression of the head, which is not reaching the margin of the adjacent puncture, by the maximal width of the pronotum which is as wide as width of elytra at humeri, and by lacking the roof-like elevation at the mid-line on the posterior part of the metaventral process. From L. zeyai and L. sibiricus , it differs by the presence of humeral macrosetae on the elytra and by lacking the sharp visible edge on lateral margins of the pronotum in the lateral view, and by the prolonged and slender tibiae. From L. zerchei it differs by lacking the sharp edge on lateral margins in the lateral view on the pronotum and by the maximal pronotal width equal to width of elytra at humeri. From similar L. richteri it is distinguished by slightly convex ventral side of the apex of the median lobe of the aedeagus in lateral view and by slightly convergent lateral sides anteriorly in the ventral view; the apical part of spermatheca 2.06x as long as wide, 0.76x as long as the basal part; while at L. richteri the ventral side of apex on the median lobe of the aedeagus is straight in the lateral view and lateral sides are convergent anteriorly in the ventral view, the apical part of spermatheca is 3.56 x as long as wide and 1.15 x as long as the basal part.

Host ant. Unknown.

Distribution. Russia (Ural, western Siberia (Tyumen) , south of Primorsky territory).

Figures

FIGURES 57–67. Lomechusoides dudkorum sp. nov. 57, female paratype, dorsal habitus; 58–62, male holotype, (locality: Russia: Tyumen). 58, pronotum in dorsal view (L: 1.15 mm, W: 2.00 mm); 59, aedeagus, lateral view; 60, aedeagus, ventral view; 61, metaventral process; 62, apex of paramere; 63–67, female paratypes. 63, antennomeres III–IV, (locality: Russia: Tyumen); 64, spermatheca, (locality: Russia: Tyumen); 65, spermatheca, (locality: Russia: Tyumen); 66, spermatheca, (locality: Russia: Urengoy); 67, spermatheca, (locality: Russia: Primorsky territory). Scale bars in mm.