Lomechusoides strumosus, Fabricius, 1792

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 : 542-543

Key to the species of the Lomechusoides strumosus group

1 Lateral sides of pronotum lacking macrosetae, posterior corners with or without one long macroseta ( Figs 2 , 9 , 13 , 21 , 31 ), anterior part of elytra with 2–4 macrosetae, humeral part lacking macrosetae, body smaller, 4.65–5.10 mm ( L. inflatus complex)............................................................................................ 2

- Lateral sides of pronotum with 4–7 macrosetae ( Figs 35 , 44 , 51 , 58 , 69 , 76 , 83 , 89 , 95 , 103 , 110 , 120 , 125 , 134 , 140 , 148 , 155 ), anterior part of elytra with 6–9 macrosetae, humeral part with 1–2 macrosetae, body usually larger, 5.35–8.00 mm (except L. dlabolai , L. reitteri and L. zeyai at 4.45–4.95 mm)........................................................... 6

2 Pronotum unicoloured, pronotal disc and lateral margins of pronotum yellow...................................... 3

- Pronotum bicoloured, disc of pronotum clearly darker than lateral margins of pronotum............................. 5

3 Head entirely yellow, the same colour as pronotum; Russia (Yakutia)............................... poppiusi sp. nov.

- Head bicoloured, some parts of head darker than pronotum.................................................... 4

4 Lateral sides of pronotum weakly divergent posteriad, strongly concave at midlength, apical part of spermatheca curved, constricted at middle, apex pointed; Russia: (Krasnoyarsk territory)............................ chekanovskiyi sp. nov.

- Lateral sides of pronotum strongly divergent posteriad, straight at midlength; apical part of spermatheca of same width along entire length, margins subparallel, apex rounded; Russia: (Yakutia).................................. drobovi sp. nov.

5 Lateral margins of pronotum widely yellowish-red, pale areas of pronotum in dorsal view not equally wide, widest in anterior half and clearly narrowed posteriorly; pronotal surface punctate, lacking visible tubercles; antennomeres III–IV in males with many reduced setae ( Fig. 19 ), head bicoloured; lateral sides of posterior corners of pronotum with one macroseta, insertion of macroseta visible; apical part of spermatheca about 1.27x as long as basal part ( Fig. 18 ); Mongolia (northern territory)......................................................................................... inflatiformis sp. nov.

- Lateral margins of pronotum narrowly yellowish-red, pale areas of pronotum in dorsal view subequally wide, at most very slightly narrower posteriorly; pronotal surface punctate, tubercles well-defined; antennomeres III–IV in males with many long setae ( Fig. 29 ), head unicoloured, brown; posterior corners of lateral sides of pronotum lacking macrosetae; apical part of spermatheca about 1.50x as long as basal part ( Fig. 26, 27, 28 ; Sweden, Finland, northern Russia..................................................................................................... inflatus ( Zetterstedt, 1828)

6 Elytra with dense, large and shallow punctures, diameter of puncture about twice of the width of setal base, distance between most punctures subequal or less than diameter of puncture ( Fig. 36 ) ( mongolicus complex)........................... 7

- Elytra with fine punctures, diameter of puncture subequal to width of setal base, distance between punctures 1.5–3.0x the diameter of puncture ( Fig. 126 ) ( strumosus complex)......................................................... 8

7 Antennomeres robust and short, pedicel wider than long, antennomere III about 1.20x as long as wide, antennomere IV as long as wide, barrel-shaped; antennomeres V–X oval, elongate; China, Mongolia, Russia (Altai, eastern Siberia, Far East)................................................................................... mongolicus (Wasmann, 1897)

- Antennomeres slender and elongate, pedicel as long as wide, antennomere III about 1.50x as long as wide, antennomere IV about 1.25x as long as wide, oval, antennomeres IV–X oval, elongate; China (Qinghai)............... przewalskyi sp. nov.

8 Small species (♁: TL 4.50 mm), unicoloured, body entirely yellow.............................................. 9

- Large species (♁: TL 4.95–8.00 mm), bicoloured, at least head, disc of pronotum, anterior part of visible tergites and ventrites IV–VI darker....................................................................................... 10

9 Temples behind eyes straight, slightly convergent posteriad, anterior half of lateral sides of pronotum widely rounded, in posterior half straight and divergent posteriad, pronotum at posterior corners as wide as humeral width of elytra; Mongolia (western and central territory), Russia (Tuva)................................................... dlabolai sp. nov.

- Temples behind eyes slightly constricted, subparallel posteriad, anterior third of lateral sides of pronotum narrowly rounded, in posterior two thirds straight and divergent posteriad, pronotum at posterior corners slightly narrower than humeral width of elytra; Russia (Amur area)................................................................... reitteri sp. nov.

10 Pronotum rectangular, lateral sides subparallel ( Figs 76 , 83 , 125 , 140 ), straight or posteriorly slightly convex........... 11

- Pronotum trapezoidal, lateral sides posteriorly clearly divergent ( Figs 58 , 69 , 95 , 103 , 110 , 120 , 134 , 148 , 155 ).......... 14

11 Pronotum unicoloured, the same colour on the whole surface.................................................. 12

- Pronotum bicoloured, disc darker than lateral portion........................................................ 13

12 Posterior half of temples straight and slightly divergent posteriad, tubercles weakly-defined on disc of pronotum, posterior part in median line of metaventral process with impression ( Fig. 79 ); apex of apical part of spermatheca pointed, transversal crest of aedeagus with distinct tubercle ( Fig. 77 ); Italy (Trentino-Alto Adige)............................ folgaricus sp. nov.

- Posterior half of temples concave, tubercles well-defined on disc of pronotum, posterior part in median line of metaventral process lacking impression ( Fig. 130 ); apex of apical part of spermatheca round, transversal crest of aedeagus lacking distinct tubercle ( Fig. 127 ); Europe, Russia (European territory and Baikal region).................. strumosus ( Fabricius, 1792)

13 Surface of lateral impressions on pronotum evenly microsculptured, disc of pronotum lacking microsculpture, shiny; lateral sides of pronotum straight or slightly concave; anterior third of lateral margins of pronotum thickened in lateral view, equally thin posteriad, with visible sharp edge in posterior third; elytra with rasp-like punctures; Russia: Far East.................................................................................................... primoricus sp. nov.

- Surface of lateral impressions on pronotum in basal part unevenly microsculptured, disc of pronotum with uneven microsculpture, slightly shiny; lateral sides of pronotum slightly convex; anterior third of lateral margins of pronotum thickened in lateral view, margins thickest at middle, becoming thinner toward anterior and posterior angles, lacking visible sharp edge; elytra lacking rasp-like punctures; Finland and Sweden................................................... wellenii ( Palm, 1949)

14 Antennae long (3.4–3.7 mm), antennomeres V and VI more than 1.85x as long as wide; temples just behind eyes straight, slightly divergent posteriad; China (Gansu).............................................. penicillatus Assing, 2015

- Antennae short (2.7–3.2 mm), antennomeres V and VI less than 1.65x as long as wide; temples just behind eyes narrowed, lateral sides of temples straight or slightly constricted and divergent posteriad.................................... 15

15 Lateral sides of pronotum concave at middle, strongly divergent in posterior third, angles of posterior corners sharp, lateral margins of pronotum in lateral view thickened in anterior and posterior thirds, thinnest in median third, with visible sharp edge, humeral part of elytra lacking macrosetae................................................................. 16

- Lateral sides of pronotum straight at middle or slightly convex, posterior two thirds weakly divergent, angles of posterior corners right or obtuse, lateral margins of pronotum in lateral view thickened in anterior two thirds, with or without visible sharp edge in posterior third, humeral part of elytra with macrosetae............................................ 17

16 Antennae short, in female antennomeres V–X barrel-shaped, (male unknown), antennomere IV: 0.91x as long as wide, almost spherical, antennomere V: 1.08x and X: 1.18x as long as wide, basal part of spermatheca ∞-shaped, apical part about 3.00x as long as wide, slightly curved and subparallel-sided; Russia (Amur area)................................ zeyai sp. nov.

- Antennae long, antennomeres IV–X oval in both sexes, antennomeres IV: 1.25x as long as wide, oval, antennomere V: 1.63x and X: 1.61x as long as wide, spermatheca with simple V-shaped basal part, apical part about 2.67 x as long as wide, apical part slightly convergent apically; Russia (Siberia)......................................... sibiricus Motschulsky, 1844

17 Maximal pronotal width greater than width of elytra at humeri, pronotum at posterior corners about as wide as elytra at humeri, lateral margins of pronotum in lateral view thickened in anterior half, abruptly becoming slender in posterior half, and markedly curved posteriad with visible sharp edge; Russia (Primorsky territory)............................... zerchei sp. nov.

- Maximal pronotal width equal to or less than width of elytra at humeri, pronotum at posterior corners narrower than elytra at humeri, lateral margins of pronotum in lateral view thickened in anterior half, gradually becoming thinner and slightly curved posteriad, lacking visible sharp edge..................................................................... 18

18 Lateral impressions on pronotum narrow, equally wide along its entire length, slightly deeper in posterior part, microsculptured and unevenly punctate, with visible tubercles, disc unevenly and sparsely punctate, punctures on disc with tubercles almost invisible, disc clearly convex........................................................................... 19

- Lateral impressions on pronotum wider, becoming broader and deeper in posterior part, microsculptured with sparse, uneven punctation, with visible tubercles, disc unevenly and densely punctate, punctures on disc with well-visible tubercles, disc slightly convex...................................................................................... 20

19 Antennae robust, ratio of length of antenomeres: V/IV about 1.00, ratio of length / width of antennomeres V–X about 1.14, 1.33, 1.25, 1.25, 1.16 and 1.36; frontal median impression on head with dull microsculpture, similar to rest of head, anterior half of impression with well-defined punctures, rest of head and posterior half of impression lacking punctures; Italy (Abruzzi).............................................................................................. rossii sp. nov.

- Antennae slender, ratio of length of antennomeres V/IV about 1.16, ratio length / width of antennomeres V–X about 1.47, 1.50, 1.50, 1.55, 1.40 and 1.47; frontal median impression on head shiny, differing from dull microsculpture on rest of head, frontal impression and disc of head with large shallow punctures, rest of head with fine well-defined punctures; Georgia, Armenia, Turkey, Azerbaijan and probably Iran................................................... teres Eppelsheim, 1884

20 Disc of pronotum unevenly microsculptured, with shiny spots, pronotal disc densely punctate, punctures with well-defined tubercles, lateral sides of pronotum slightly divergent posteriad; Russia (Primorsky territory).............. fallax sp. nov.

- Disc of pronotum evenly microsculptured, lacking shiny spots................................................. 21

21 Antennomere X slender, cone-shaped ( Fig. 123 ), setae on frontal impression of head fine and long, exceeding margin of adjacent puncture, lateral sides of pronotum in posterior third slightly concave, divergent posteriad, maximal pronotal width at posterior corners, here slightly narrower than elytra at humeri; metaventral process at mid-line with roof-like elevation; Italy (Sicily)............................................................................... siculus Fiori, 1914

- Antennomere X with basal part cone-shaped, apical part cylindrical ( Figs 63 , 101 ), setae on frontal impression of head thick and short, not reaching margin of adjacent puncture, anterior half of lateral sides of pronotum rounded, sligthly convex toward anterior corners, divergent posteriad, maximal pronotal width shortly before posterior corners, here as wide as elytra at humeri; metaventral process at mid-line lacking roof-like elevation................................................... 22

22 Ventral side of median lobe of aedeagus slightly convex in lateral view ( Fig. 59 ), lateral sides slightly convergent anteriorly in ventral view ( Fig. 60 ); apical part of spermatheca 2.06x as long as wide, 0.76x as long as basal part ( Fig. 64, 65, 66 and 67 ); Russia (Ural, western Serbia (Tyumen))..................................................... dudkorum sp. nov.

- Ventral side of median lobe of aedeagus straight in lateral view ( Fig. 96 ), lateral sides convergent anteriorly in ventral view ( Fig. 97 ); apical part of spermatheca 3.56x as long as wide, 1.15x as long as basal part ( Fig. 100 ); Russia: (Saratovsk district)........................................................................................ richteri sp. nov.

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.

FIGURES 8–11. Lomechusoides drobovi sp. nov., female holotype. 8, dorsal habitus; 9, pronotum in dorsal view (L: 0.90 mm, W: 1.45 mm); 10, metaventral process; 11, spermatheca. Scale bar in mm.

FIGURES 12–19. Lomechusoides inflatiformis sp. nov. 12, female paratype, dorsal habitus; 13–17, male holotype. 13, pronotum in dorsal view (L: 0.90 mm, W: 1.45 mm), 14, aedeagus, lateral view; 15, aedeagus, ventral view; 16, metaventral process; 17, apex of paramere; 18, female paratype, spermatheca; 19, male paratype, antennomeres III–IV. Scale bars in mm.

FIGURES 20–29. Lomechusoides inflatus Zetterstedt, 1828. 20, Lomechusoides mariae Palm, 1949, male lectotype, dorsal habitus; 21, L. mariae, male lectotype, pronotum in dorsal view (L: 0.90 mm, W: 1.35 mm); 22, L. mariae, male paralectotype, aedeagus, lateral view; 23, L. mariae, male paralectotype, aedeagus, ventral view; 24, L. mariae, male lectotype, metaventral process; 25, L. mariae, male paralectotype, apex of paramere; 26, L. inflatus, female holotype, spermatheca; 27, L. mariae, female paralectotype, spermatheca, (locality: Kihlangi); 28, L. mariae, female, spermatheca (locality: Soppero); 29, L. inflatus, male, antennomeres III–IV, (locality: Kihlangi). Scale bars in mm.

FIGURES 30–33. Lomechusoides poppiusi sp. nov., female holotype. 30, dorsal habitus; 31, pronotum in dorsal view (L: 1.00 mm, W: 1.50 mm); 32, metaventral process; 33, spermatheca. Scale bar in mm.

FIGURES 34–42. Lomechusoides mongolicus Wasmann, 1897. 34, female lectotype, dorsal habitus; 35, female lectotype, pronotum in dorsal view (L: 1.15 mm, W: 1.75 mm); 36, male, microstructure of elytra with setation, (locality: Primorsky territory, about 40 km WSW from Vladiwostok); 37, male, aedeagus, lateral view; 38, male, aedeagus, ventral view; 39, male, metaventral process; 40, male, apex of paramere [Figs. 37–40 (locality: China: Inner Mongolia: Donkyra, pass Djusso)]; 41, female lectotype, spermatheca, (locality: Mongolia: Changai); 42, female, spermatheca, (locality: East Siberia: Irkutsk area). Scale bars in mm.

FIGURES 43–49. Lomechusoides przewalskyi sp. nov., 43–48, male holotype. 43, dorsal habitus; 44, pronotum in dorsal view (L: 1.25 mm, W: 2.00 mm); 45, aedeagus, lateral view; 46, aedeagus, ventral view; 47, metaventral process; 48, apex of paramere; 49, female paratype, spermatheca. Scale bars in mm.

FIGURES 50–56. Lomechusoides dlabolai sp. nov. 50, male paratype, dorsal habitus; 51–55, male holotype. 51, pronotum in dorsal view (L: 0.90 mm, W: 1.45 mm); 52, aedeagus, lateral view; 53, aedeagus, ventral view; 54, metaventral process; 55, apex of paramere; 56, female paratype, spermatheca, locality: Mongolia Zaisan. Scale bars in mm.

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.

FIGURES 68–74. Lomechusoides fallax sp. nov. 68, female paratype, dorsal habitus; 69–73, male holotype, (locality: Russia: Primorsky territory, Anisimovka). 69, pronotum in dorsal view (L: 1.05 mm, W: 1.82 mm); 70, aedeagus, lateral view; 71, aedeagus, ventral view; 72, metaventral process; 73, apex of paramere; 74, female paratype, spermatheca, (locality: Russia: Primorsky territory, Anisimovka). Scale bars in mm.

FIGURES 75–81. Lomechusoides folgaricus sp. nov. 75, male paratype, dorsal habitus; 76–80, male holotype; (locality: Italy, Folgaria, Tirolis). 76, pronotum in dorsal view (L: 1.15 mm, W: 1.75 mm); 77, aedeagus, lateral view; 78, aedeagus, ventral view; 79, metaventral process; 80, apex of paramere; 81, female paratype, spermatheca, (locality: Italy, Folgaria, Tirolis). Scale bars in mm.

FIGURES 82–88. Lomechusoides primoricus sp. nov. 82, male paratype, dorsal habitus; 83–87, male holotype (locality: Russia: Primorsky territory: Sikhote-Alin). 83, pronotum in dorsal view (L: 1.10 mm, W: 1.85 mm); 84, aedeagus, lateral view; 85, aedeagus, ventral view; 86, metaventral process; 87, apex of paramere; 88, female paratype, spermatheca, (locality: Russia: Primorsky kray: Sikhote-Alin). Scale bars in mm.

FIGURES 89–93. Lomechusoides reitteri sp. nov., male holotype. 89, pronotum in dorsal view (L: 0.85 mm, W: 1.30 mm); 90, aedeagus, lateral view; 91, aedeagus, ventral view; 92, metaventral process; 93, apex of paramere. Scale bars in mm.

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.

FIGURES 102–108. Lomechusoides rossii sp. nov. 102–107, male holotype. 102, dorsal habitus; 103, pronotum in dorsal view (L: 1.10 mm, W: 1.85 mm); 104, aedeagus, lateral view; 105, aedeagus, ventral view; 106, metaventral process; 107, apex of paramere; 108, female paratype, spermatheca. Scale bars in mm.

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.

FIGURES 119–123. Lomechusoides siculus Fiori, 1914, female, (locality: Italia-Sicily: Castelbuono). 119, dorsal habitus; 120, pronotum in dorsal view (L: 1.10 mm, W: 1.72 mm); 121, metaventral process; 122, spermatheca; 123, antennomeres IX–X. Scale bars in mm.

FIGURES 124–132. Lomechusoides strumosus Fabricius, 1792. 124, male, dorsal habitus; 125, male, pronotum in dorsal view (L: 1.07 mm, W: 1.77 mm), (locality: Bohemia: Týn nad Vltavou); 126, male, microstructure of elytra with setation; 127, male, aedeagus, lateral view; 128, male, aedeagus, ventral view; 129, female, antennomeres IX–X, (locality: Bohemia: Týn nad Vltavou); 130, male, metaventral process; 131, male, apex of paramere; 132, female, spermatheca, (locality: Bohemia: Týn nad Vltavou). Scale bars in mm.

FIGURES 133–138. Lomechusoides teres Eppelsheim, 1884, male lectotype. 133, dorsal habitus; 134, pronotum in dorsal view (L: 0.90 mm, W: 1.42 mm); 135, aedeagus, lateral view; 136, aedeagus, ventral view; 137, metaventral process; 138, apex of paramere. Scale bars in mm.

FIGURES 139–146. Lomechusoides wellenii Palm, 1949. 139, male paralectotype, dorsal habitus; 140, pronotum in dorsal view (L: 1.15 mm, W: 1.85 mm), (locality: Svecia, Svartbyn); 141, male, aedeagus, lateral view; 142, male, aedeagus, ventral view; 143, male, metaventral process; 144, apex of paramere; 145, female, spermatheca, (locality: Svecia, Sangis); 146, female, spermatheca, (locality: Fennia Nyl., Helsinge). Scale bars in mm.

FIGURES 147–153. Lomechusoides zerchei sp. nov. 147, male paratype, dorsal habitus; 148–152, male holotype, (locality: Russia: Primorsky territory,Anisimovka). 148, pronotum in dorsal view (L: 1.45 mm, W: 1.93 mm); 149, aedeagus, lateral view; 150, aedeagus, ventral view; 151, metaventral process; 152, apex of paramere; 153, female paratype, spermatheca. Scale bars in mm.

FIGURES 154–157. Lomechusoides zeyai sp. nov., female holotype. 154, dorsal habitus; 155, pronotum in dorsal view (L: 1.00 mm, W: 1.60 mm); 156, metaventral process; 157, spermatheca. Scale bar in mm.