Lomechusoides Tottenham, 1939

Jászay, Tomáš & Hlaváč, Peter, 2013, A taxonomic revision of the myrmecophilous genus Lomechusoides Tottenham, 1939 (Coleoptera: Staphylinidae: Aleocharinae) Part I. Redescription of the genus, definition of species groups and th, Zootaxa 3683 (1), pp. 65-81: 66-67

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Lomechusoides Tottenham, 1939


Genus Lomechusoides Tottenham, 1939 

Lomechusoides Tottenham, 1939: 226  . Type species: Staphylinus strumosus Fabricius, 1793  , original designation

Goniodes Stephens, 1829: 260  . Type species: Staphylinus strumosus Fabricius, 1793  , virtual monotypy (attributed to Kirby; preoccupied, not Nitzsch, 1818)

Lomechusa Gravenhorst  : Erichson, 1839 (redescription); Ganglbauer, 1895 (redescription); Wasmann, 1897 (revision, key); Wasmann, 1888 (biology); Feynes, 1920: 304 (redescription, catalogue, distribution); Bernhauer, 1936 (key to known species)

Lomechusoides Tottenham  : Maruyama & Hlaváč, 2004 (catalogue, new combinations, synonyms)

Diagnosis. The genus Lomechusoides  can be readily separated from between three genera of the subtribe Lomechusina  by the combination of following characters: 1) antennae and legs stout, 2) pronotum with lateral part dull, finely microsculptured and 3) lacinia without hook or spine.

Redescription. Body yellowish-brown ( Fig. 48View FIGURES 48 – 50. 48, L), pronotum partly darker, elytra and tergites lighter, some tergites with basal part darker.

Head: ( Fig. 1View FIGURES 1 – 6. L) quadrate, longer than wide, or as long as wide, eyes weakly protuberant, shorter than temples, temples slightly convergent posteriorly or parallel, surface with sparse puncturation and setation, with microsculpture, matt with frontal triangular depression between well developed antennal protuberances. Labrum bilobed, wider than long, with some setae. Mandibles ( Fig. 2View FIGURES 1 – 6. L) symmetric, angularly bent, lacking internal teeth, basal dorsal part in middle with numerous dentiform protuberances, lateral edge with dense setation. Maxillae ( Fig. 3View FIGURES 1 – 6. L) with galea longer than lacinia, both of about same width, galea evenly expanded in basal part, in apical part narrowed, palpifer and stipes with setae, maxillary palpi 4 -segmented, palpomere I small, subquadrate, II expanded apically, widest, III slightly shorter and slender, IV as long as I, needle-like. Labium ( Fig. 4View FIGURES 1 – 6. L) with prementum slighty longer than wide in basal part, anterior part with numerous setae, basal part with numerous pseudopores, glossy, indistinctly divided in two rounded lobes, lacking sensillae, labial palpi with palpomere I barrel-like, 1.5 as long as wide, about three times as long as II, palpomere II shortest, trapezoidal, wider than long, palpomere III narrowest, subparallel, three times as long as wide, as long as II, palpomere I and II with setae, III with some pseudopores. Mentum ( Fig. 5View FIGURES 1 – 6. L) rhomboidal, 1.3 times as wide as long, widest at base, narrowed anteriorly, anterior margin deeply excavated, in lateral anterior and posterior corners with about seven pseudopores, in middle with about four pseudopores. Gular suture widely separated, closest in middle, suddenly narrowed anteriorly and evenly narrowed posteriorly. Antennae ( Fig. 6View FIGURES 1 – 6. L) long, when bent backwards usually reaching or exceeding base of elytra, all antennomeres more or less asymmetric, scape large, larger than all other antenommeres individually, pedicel smallest, II–III rhomboid, both slightly pedunculate, IV–X barrel-like shaped, terminal antennomere pointed apically, longest, all antennomeres matt, with setation, antennomeres III–IV in males with bunch of lateral setae (absent in L. suensoni  ). Pronotum ( Figs. 7, 8View FIGURES 7 – 13. L) variable in shape and size, transverse, widest at base, anterior angles rounded, posterior angles well-defined, sharp, surface sometimes with tubercles, basal margin with strong median lobe, surface with various depressions, pronotal disc with uneven puncturation, with or without microsculpture, hypomeron large and matt. Mesoventrite wide, five times as wide as mid-line length, with short and fine setae, surface with microsculpture, posterior mesoventral process truncated. Metaventrite ( Fig. 9View FIGURES 7 – 13. L) about four times as long as mesoventrite, surface unevenly punctured, setaceous, with or without microsculpture, macrosetation species-characteristic, shape of metaventral process species-characteristic, with or without depression.

Elytra as long as or shorter than pronotum, elytron about as long as wide or slightly shorter, finely punctured with setation, in basal and humeral part with macrosetae, posterior margin of elytra in front of posterior corner excavated, angle of sutura rounded, wings well-developed.

Abdomen robust, evenly expanded, tergite V widest, from tergite V slightly convergent posteriorly, abdomen longer than head, pronotum and elytra combined. Paratergites III–V with trichomes, lateral margins of tergites II– IV, VIII–X as well as lateral margins of sternites II–IV and metepimeron with dense golden setae, tergites V–VII in posterior corners with short setae, surface with or without weak microsculpture, sternites evenly punctured with erect macrosetae.

Legs long, with setation, apical part of femora with bunch of long setae ( Fig. 10View FIGURES 7 – 13. L) (groups L. amurensis  and L. strumosus  ) or lacking any long setae (groups L. minor  and L. straneoi  ), tarsal formula 4-5 - 5, trochanters similarly shaped, semi-triangular, procoxae about three times as long as wide, mesocoxae 1.3 times as long as wide and metacoxae about as long as wide, tibiae slightly shorter than femora, slightly convergent posteriorly, coxae, trochanters and ventral part of femora with few macrosetae.

Sexual dimorphism. setae on antenommeres III–IV longer in males ( Fig. 6View FIGURES 1 – 6. L), tergites and sternites VIII differently shaped in males and females ( Figs. 11View FIGURES 7 – 13. L a, 11 b, 12 a, 12 b).

Distribution. Almost the whole Palaearctic region, from Spain to Siberia and Russian Far East, China and Japan.

Biology. Lomechusoides  is a strictly myrmecophilous genus with symphilic way of life which so far has been recorded only with ants of the genus Formica Linnaeus, 1758  and Myrmica Latreille, 1804  . The following ants have been found as hosts of Lomechusoides  so far: Formica cunicularia Latreille, 1798  ; F. f u s c a Linnaeus, 1758, F. pratensis Retzius, 1783  ; F. r u f a Linnaeus, 1761; F. rufibarbis Fabricius, 1793  ; F. sanguinea Latreille, 1798  ; Myrmica rubra Linnaeus, 1758  and M. scabrinodis Nylander, 1846  .












Lomechusoides Tottenham, 1939

Jászay, Tomáš & Hlaváč, Peter 2013



Tottenham 1939: 226



Stephens 1829: 260