Lomechusoides sibiricus Motschulsky, 1844

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 : 576-578

Lomechusoides sibiricus Motschulsky, 1844

Figs 109–118

Lomechusa sibirica Motschulsky, 1844: 816

Lomechusa sibirica Motschulsky : Motschulsky, 1860: 584; Hochhuth, 1862: 14; Eppelsheim, 1886: 430; Wasmann, 1894: 62, 205; Wasmann, 1896: 248. Type data: Russia: Siberia: Daurien? [ZMMU].

Material studied. LECTOTYPE, ♁, present designation: RUSSIA: (h) Lomechusa sibirica mihi, cum F. rufa major, Transbaicalia / (h) 201 / (h) Lomechusoides sibiricus (Motsch.) (p) V. B. Semenov det. (h) 1998 / red label (h) LECTOTYPUS Lomechusa sibirica Motsch.,V.B. Semenov dsg. 1998 /red label (p) LECTOTYPE ♁ Lomechusoides sibiricus ( Motschulsky, 1844) des. Jászay & Hlaváč, 2020 ( ZMMU). PARALECTOTYPE, 1 ♀: RUSSIA: pink label (h) Kul Bäder, cum F. rufa major, V. B. Semenov scrpt. 1998 / red label (h) PARALECTOTYPUS, Lomechusa sibirica Motsch., V. B. Semenov des. 1998. ( ZMMU). 1♁: pink label (h) Kul Bäder “hand written illigible text” F. rufa major, V. B. Semenov scrpt. 1998 / red label (h) PARALECTOTYPUS, Lomechusa sibirica Motsch., V. B. Semenov des. 1998. ( ZMMU). Both paralectotypes are bearing printed red label: PARALECTOTYPE ♁ or ♀ Lomechusoides sibiricus ( Motschulsky, 1844) des. Jászay, Hlaváč & Baňař, 2021. Other material studied. Russia: 1♀: (h) Sibiria Dauria/ (h) Lomechusa sibirica / (p) (russian) к. Кенига [=coll. König] / (h) L. sibirica Motsch. (p) W. Schilov det. 19/ green label (p) Inst. St. Petersburg. ( ZIN). 1♀: (h) Бура.[=Bura] / (h) Sibiria (B. Jakovlev № 2/(h) Lomechusa sibirica Motsch. III. 99 (p) A. Semenov det./(h) L. sibirica Motsch. (p) W. Schilov 19/ green label (p) Inst. St. Petersburg. ( ZIN). 1♁ 1♀: (p) 119/(p) Coll. Weise/(h) sibirica Motsch., Sibir /(p) Coll. DEI Eberswalde ( DEI). 1♀: (h) Sibiria/(p) coll. Stierlin/(h) L. sibirica Motsch., Faust /(p) Coll. DEI Eberswalde ( DEI). 1♀: (h) ЧитинскаЯ обл. Харанор в р-не 1-го ключа КерЖнер 8.VII.1963./(h) ± влаЖные пески [=Chitinskaya obl. Kharanor v r-ne 1-go klyucha, Kerzhner 8.VII.1963 / (h) vlazhnye peski = Chitinskaya oblasť Kharanor v rayone pervogo klyucha, Kerzhner 8.VII.1963 / (h) vlazhnye peski (=wet sands)] ( ZIN).

Note: The correct identification of syntypes is rather problematic, the description of Motschulsky is very short " Lomechusa sibirica m. der L. strumosa sehr ähnlich, aber etwas gr̂sser. Am Rande der Nester F. rufa minor , tief im Neste kam sie mir nicht vor." and it gives no information about the type locality. All studied specimens are also bearing the lectotype or the paralectotype label of Semenov. This designation has never been published.

Description. Body light reddish-brown ( Fig. 109 ) except anterior margin of visible tergites II–IV, basal half of anterior margin of visible tergite V, larger part of anterior margin of visible tergites VI–VII, lateral part of visible sternites III–IV, larger part of posterior margin of visible sternite V, larger part of anterior margin of visible sternite VI and anterior margin of visible sternite VII brown.

Head subrectangular, slightly longer than wide, ratio HW/HL: ♁ 0.96, ♀ 0.84, with deep, broad, V-shaped frontal median impression, which is unevenly microsculptured, finely and barely punctate, weakly shiny; disc of head microsculptured and finely punctate, dull; length of eyes ♁ 0.23x, ♀ 0.21x of length of head; eyes slightly protuberant, temples behind eyes constricted, slightly concave, subparallel posteriad. Antennae long, scape ♁ 1.61x, ♀ 1.57x as long as wide and ♁ 2.27x, ♀ 2.44x as long as pedicel, pedicel ♁ 1.00x, ♀ 1.00x as long as wide, antennomere III: ♁ 1.80x, ♀ 1.57x, IV: ♁ 1.25x, ♀ 1.36x, V: ♁ 1.63x, ♀ 1.61x as long as wide, antennomeres V–VIII oval elongate, terminal segment slender and acute, ♁ 1.24x, ♀ 1.41x as long as scape, relative length of antennomeres from base to apex: ♁: 25: 11: 18: 15: 18: 18: 18:17: 15: 17: 31; ♀: 22: 9: 15: 15: 17: 17: 16: 16: 18: 17: 31.

Pronotum ( Fig. 110 ) trapezoidal, ratio PW/PL: ♁ 1.68, ♀ 1.68, with concave anterior margin, anterior corners obtuse, lateral sides in anterior third broadly rounded, in middle third concave, in basal third slightly extended and divergent posteriad, narrowed just before basal corners, basal corners acute, bearing deep microsculpture, lateral impressions densely punctate, lateral impressions are extended in middle towards lateral margins, pronotal disc with slightly visible microsculpture, slightly and sparsely punctate, tubercles well-defined; median line well-defined, narrow; in lateral view lateral margins in anterior third thick, in posterior third clearly thinner, in median third thin, with visible sharp edge; maximal pronotal width just before posterior corners, here as wide as elytra at humeri; pronotum with macrosetae, anterior margin with about four and lateral margins with about four macrosetae.

Anterior and lateral margins of metaventral process ( Fig. 113 ) concave, anterior part with slightly transversal carinate elevation, and with subparallel lateral lines, posterior part in median line with barely visible lentil-like impression, metaventral process microsculptured and regularly punctate; metaventral disc with narrow lines on sides of median line, lines divergent posteriad, metaventrite microsculptured and sparsely punctate, discal setae long, exceeding margin of adjacent puncture.

Elytra finely and densely punctate, elytra ♁ 0.95x ♀ 0.93x as long as pronotum, ratio EW/EL: ♁ 2.00, ♀ 2.07, anterior part with about three to four macrosetae, on humeral part lacking macrosetae, distance between punctures on disc twice as long as diameter of puncture.

Abdomen with visible tergites II–IV densely punctate and setaceous on posterior margin, visible tergite V with sparse and fine puncturation, visible tergites VI–VII with sparse puncturation on whole surface, lateral parts with weak and denser puncturation, visible tergites II–VII unevenly microsculptured, sporadically visible on posterior margins and on lateral sides.

Aedeagus ( Figs 111–112 ) with robust median lobe, apical lobe tube-like, apical part short and sharp, with scattered pseudopores, ventral side slightly convex in lateral view, lateral sides of apical lobe subparallel in ventral view. Apical lobe of parameres before apex slightly constricted ( Fig. 115–116 ), slightly hook-shaped, apex with about 3 setae and few scattered pseudopores lacking microsetae.

Spermatheca ( Figs 117–118 ) with apical part 1.31x as long as basal part and 1.24x wider than basal extended part, 2.67x as long as wide, apical part in middle short, subparallel, convergent apically, apex rounded.

Measurements. (♁, Lectotype): TL 5.35 mm; FB 2.75 mm; HL 0.85 mm; HW 0.82 mm; antennal length 3.20 mm; PL 1.10 mm; PW 1.85 mm; EL 1.05 mm; EW 2.10 mm; FTL 1.10 mm; MTL 1.40 mm; HTL 1.60 mm. (♀, Paralectotype): TL 5.40 mm; FB 2.70 mm; HL: 0.95 mm; HW 0.80 mm; antennal length 3.05 mm; PL 1.07 mm; PW 1.80 mm; EL 1.00 mm; EW 2.07 mm; FTL 1.15 mm; MTL 1.40 mm; HTL 1.70 mm.

Differential diagnosis. L. sibiricus is separated from L. folgaricus , L. primoricus , L. strumosus and L. wellenii by the trapezoidal shape of the pronotum. From L. dlabolai and L. reitteri it can be distinguished by the large and bicoloured body. From L. penicillatus , it differs by shorter antennomeres. L. sibiricus , with the exception of L. zeyai , differs from all other species of the L. strumosus complex by the shape of the pronotum, by concave lateral sides of the pronotum at the midlength, which are extended and divergent in the posterior third and by the lack of humeral macrosetae on the elytra. From L. dlabolai , L. dudkorum , L. fallax , L. reitteri , L. richteri , L. rossii , L. siculus and L. teres by the presence of a sharp edge which is in the middle third of lateral margins of pronotum in lateral view. From similar L. zeyai it differs by the lighter colouration, by the slender elongate antennomeres IV–X, by the longer pedicel as well as elongate antennomere IV, by the sparse punctation on the whole surface of visible tergites VI–VII, by having tibiae of all legs slightly more robust, long and equally thick along their length, and by having foretibiae straight, while the midtibiae and hindtibiae are clearly curved.

Host ant. Formica sanguinea Latreille, 1798 , Formica polyctena Foerster, 1850 .

Distribution. Russia (eastern Siberia).

Figures

FIGURES 109–118. Lomechusoides sibiricus Motschulsky, 1844. 109, male, lectotype, dorsal habitus; 110, male paralectotype, pronotum in dorsal view (L: 1.10 mm, W: 1.85 mm); 111, male, aedeagus, lateral view, (locality: Sibir); 112, male, aedeagus, ventral view, (locality:Sibir); 113, male lectotype, metaventral process, (locality:Russia:Transbaikalia); 114, male paralectotype, aedeagus, lateral view, (locality: Russia: Siberia); 115, male lectotype, apex of paramere; 116, male paralectotype, apex of paramere; 117, female paralectotype, spermatheca, (locality: Russia: Siberia); 118, female, spermatheca, (locality: Sibir). Scale bars in mm.