Asiageodromicus weiperti, Shavrin, 2024

Shavrin, Alexey V., 2024, Review of Hygrogeus Mulsant & Rey, 1880 and Trichodromeus Luze, 1903, with descriptions of three new genera from the eastern Palaearctic Region (Coleoptera: Staphylinidae: Anthophagini: Omaliinae), Zootaxa 5531 (1), pp. 1-62 : 39-47

Asiageodromicus weiperti sp. n.

( Figs 67 , 79–80 , 89 )

Type material examined. Holotype ♂ (dissected; left antennomeres 9–11 missing): ‘ NEPAL, Prov. Mechi | Khangpachen bis | Ghunsa; 12.IV.2003 | 3500–4100 m NN | leg.: J. Weipert’ <printed>, ‘ HOLOTYPE | Asiageodromicus | weiperti sp.n. | Shavrin A.V. des. 2024’ <red, printed> ( NME).

Paratypes: 1 ♀: same data as the holotype (cSh); 1 ♀ (left antennomeres 5–11 and right antennomeres 7–11 missing): ‘ NEPAL Mechi /Taplejung | 500m NE Ghunsa | 35–3600m 10.V.2003 ’ <printed>, ‘ 27°39’48’’N,87°56’36’’ | leg. A.Weigel HF | stone debris/mix[ed].forest’ <printed> ( NME). All paratypes with addtional red printed label: ‘ PARATYPE | Asiageodromicus | weiperti sp.n. | Shavrin A.V. des. 2024’.

Description. Measurements (n=3): HW: 1.17–1.22; HL: 0.78–0.82; OL: 0.27–0.29; TL: 0.10–0.14; AL (holotype): 3.96; PL: 0.90–1.02; PWmax: 1.40–1.50; PWmin: 1.26–1.40; ESL: 2.11–2.24; EW: 2.38–2.61; MTbL (holotype): 1.82; MTrL (holotype): 0.69 (MTrL 1–4: 0.37; MTrL 5: 0.32); AW: 2.27–2.55; AedL: 1.62; BL: 7.20 (holotype)–7.95.

Habitus as in Fig. 67 . Body blackish; mouthparts, antennae and legs brown (tibia slightly paler); tarsi yellow-brown. Head with distinct fine isodiametric microsculpture, without meshes in basal part of clypeus, finer in middle between anteocellar foveae, larger in mediobasal part and in middle of neck; pronotum with dense isodiametric microreticulation, finer or without meshes in middle and/or mediobasal portions; scutellum with dense and moderately large transverse microsculpture; abdomen with dense transverse microreticulation, coarser on abdominal tergites V–VI. Pubescence dense, semi-erect, longer on apical part of head; abdomen with dense, but finer pubescence than that on forebody.

Head 1.4–1.5 times as broad as long, with strongly elevated median and infraorbital parts, with very deep transverse anteriomedian depression, widely narrowed basad toward slightly or deeply impressed and wide interocellar depression; anteocellar foveae deep, narrow, slightly convergent lateroanteriad and reaching level of anterior third of eyes; temples short, less than twice as long as longitudinal length of eyes (if see laterally). Ocelli very small, indistinct, located about at level of posterior margins of eyes, distance between ocelli slightly shorter than distance between ocellus and posterior margin of eyes. Clypeus without punctation; median and infraorbital portions with irregular, moderately large and dense puncation; punctation of middle portion between eyes sparser and indistinct; middle of neck without visible punctures. Last segment of maxillary palpi 1.6 times as long as preceding segment. Antennae reaching basal third of elytra when reclined; antennomere 3 significantly longer than 2, 4–7 slightly shorter than 3, 8–10 slightly slightly shorter than 7, apical antennomere 1.3–1.4 times as long as 10.

Pronotum relatively small and distinctly transverse, 1.4–1.5 times as broad as long, markedly wider in apical portion, with widely rounded and significantly protruded anteriad apical angles, and strongly narrowed posteriad toward obtuse hind angles; latero-anterior margins distinctly concave between widely rounded anterior margin; basal margin straight or indistinctly concave; narrowest laterobasal portions of pronotum very long, somewhat subparallel and slightly concave in one paratype; mediobasal portion slightly and widely impressed; laterobasal portions widely impressed, with slightly reflexed latero-basal margins. Punctation about as that on head, but slightly denser, larger and deeper, with interstices between punctures in middle about as long as diameters of one-two nearest punctures, finer and sparser in middle and mediobasal portions.

Elytra slightly broader than long, reaching apical margin of abdominal tergite III; lateral margins relatively broadly flattened, with indistinctly reflexed mediolateral margins. Punctation dense, about as that on pronotum, but slightly larger and deeper, finer around scutellum, and finer and sparser along suture.

Abdomen with wide transverse tomentose spots in middle of abdominal tergite IV and indistinct small and oval spots in middle of tergite V.

Male. Posterior margin of abdominal tergite VIII slightly and posterior margin of sternite VIIII widely concave. Aedeagus with moderately broadened median lobe, from preapical portion strongly narrowed toward slightly elongate subacute apex; parameres slightly broadened in apical parts, exceeding apex of median lobe, with two moderately short apical setae and several tiny setae along each preapical inner margin; flagellum relatively long, spirally folded in basal part ( Fig. 79 ). Lateral aspect of aedeagus as in Fig. 80 .

Female. Posterior margin of abdominal tergite VIII and sternite VIII rounded.

Comparative notes. Asiageodromicus weiperti sp. n. differs from the remaining species of the genus by the shape of the smaller pronotum, from widest part strongly narrowed posteriad, with strongly elongate narrower basal part. See also a key above.

Distribution. Asiageodromicus weiperti sp. n. is known from two locations in eastern Nepal ( Fig. 89 ).

Bionomics. Specimens were collected at elevations from 500 to 4100 m a.s.l. Detailed bionomical data are unknown.

Etymology. Patronymic, the species is named to honour Jörg Weipert (Plaue, Germany), collector of two specimens of the type serie.

Genus Himalodromeus gen. n.

( Figs 90–124 )

Type species: Hygrogeus cyanipennis Cameron, 1924 .

Description. Body large (6.00–9.45), moderately convex, usually with significantly broadened pronotum and elytra. Coloration reddish-brown to dark-brown, with bluish elytra (except H. reductus sp. n.). Punctation of head and pronotum fine and dense, larger and denser on pronotum and elytra. Body glossy; head and pronotum with dense and fine microsculpture; abdomen with distinct transverse microreticulation. Pubescence of forebody semi-erect, moderately dense and fine, longer in apical part of head; abdominal tergites with dense adjoining pubescence, finer than that on forebody.

Head transverse, with strongly convex moderately wide subantennal prominences, and distinctly elevated middle and infraorbital portions; anteriomedian depression wide and deep; interocellar depression deep and wide, subtrapezoidal or rectangular; anteocellar foveae moderately deep, slightly or strongly convergent latero-anteriad. Temples convex, shorter than longitudinal length of eyes. Eyes large, convex. Ocelli present, small or moderately large. Gular sutures relatively widely separated at level of posterior third of eyes, gradually divergent posteriorly towards base of head ( Fig. 103 ). Labrum large and wide, with widely rounded latero-apical portions and shallow apical emargination, with long and strong laterobasal projections ( Fig. 98 ). Mandibles with wide basal part; apical part elongate, strongly curved apically, with subacute apex; inner margin of left mandible with two large subtriangular teeth in about apical third; right mandible with two large subtriangular teeth in about apical third, slightly smaller than these in left mandible, with additional elongate tooth in about middle, widely rounded apically, separated from nearest tooth by deep emargination ( Fig. 99 ). Mentum narrow, with two elongate setae on each latero-apical portions ( Fig. 102 ). Labium narrow, with elongate labial palpomeres; preapical (3) labial palpomere slightly shorter than palpomere 2; apical palpomere longer than two preceding segments, slightly narrower than palpomere 3 in broadest middle, with rounded apex; glossa narrow, elongate ( Fig. 101 ). Maxilla strongly elongate, distinctly longer than two basal antennomeres, with relatively wide and elongate maxillary palpomeres 2–4, with palpomeres 2–3 covered with dense pubescence ( Fig. 100 ); maxillary palpomere 2 very long, gradually broadened apicad; maxillary palpomere 3 slightly narrower and slightly less than twice shorter than preceding segment; last maxillary palpomere elongate, distinctly longer and slightly narrower than preapical segment, from base gradually broadened toward middle, with rounded apex; galea relatively narrow and distinctly longer than lacinia, from widest basal part gradually narrowed apically; lacinia narrow, long, with elongate and strongly curved apex and seven long teeth along apical half of medial margin. Antenna reaching level of posterior third of elytra or slightly longer when reclined, with narrow elongate antennomeres; basal antennomere broadened, very long, more than four times as long as broad.

Pronotum widest slightly in front of middle or in anterior portion, distinctly more narrowed posteriad than anteriad, with wide frontal part not ( Fig. 97 ) or strongly protruded apicad ( Fig. 96 ), with relatively short subparallel laterobasal portions in front of acute or obtuse hind angles, sometimes distinctly protruded posteriad ( Fig. 96 ); middle portion without or with distinct longitudinal depression; lateral margins distinctly and narrowly bordered, sometimes slightly reflexed, with indistinct smooth crenulation. Prothorax with relatively narrow prosternum and elongate intercoxal process; pronotal epipleura significantly broadened; prosternal processes wide, widely rounded apically ( Fig. 104 ). Mesoventrite strongly transverse, with moderately short intercoxal process slightly not reaching apex of middle of mesocoxae ( Fig. 105 ). Scutellum large, with wide apical portion, rounded apically ( Fig. 108 ). Metaventrite wide, with wide and deep intercoxal cavities and wide anterior intercoxal process ( Fig. 106 ). Metendosternite as in Fig. 107 .

Elytra broader than long, longer than pronotum, lateral margins deeply and relatively widely impressed, deeper in middle; elytral epipleura slightly broadened in middle ( Fig. 109 ). Hind wings fully developed.

Legs long and slender; tibiae distinctly broadened toward apex, from about middle covered with dense setae, elongate in apical portions of tibiae; inner and outer margins of apical parts of tibiae with additional strong and long spines; males with distinctly broadened femora and protarsomeres 1–4.

Abdomen wide, with two large transverse tomentose spots in middle of abdominal tergite IV and distinct narrow palisade fringe on apical margin of abdominal tergite VII.

Male. Posterior margin of abdominal sternite VIII with very deep emargination and sometimes with long and dense setation on each latero-apical portion ( Figs 117, 122–123 ). Aedeagus long with significantly broadened median lobe and elongate apex, sometimes with narrow median sclerotized lateral lobes in middle; parameres reduced, very short, narrow, distinctly not reaching middle of median lobe; internal sac without distinct fields of spines, with elongate sclerotized structures in middle and long narrow flagellum spirally folded in basal portion; apical part of flagellum widely broadened ( Figs 110, 112, 114 ). Genital segment as in Fig. 118 .

Female. Posterior margin of abdominal sternite VIII straight ( Fig. 120 ). Gonocoxites narrow, strongly elongate; styli narow, elongate, each with moderately long apical seta ( Fig. 121 ).

Natural History. The species of Himalodromeus inhabit bank of rivers and streams, and can be found in gravel and under stones. Specimens were collected at elevations from 1900 to 4572 m a.s.l.

Distribution. Species of Himalodromeus are distributed in the Himalayan Region, and known from north-eastern Pakistan, India and western Nepal ( Fig. 124 ).

Etymology. The name of the new genus is derived from the prefix Himalo -, refering to the Himalaya, and the last part of the name of the relative genus Trichodromeus .

Remarks. Based on the similar microsculpture of the head and pronotum, the general shape of the head with wide and deep interocellar depression and somewhat elongate temples, the protruded frontal part of the pronotum and longitudinal depression in the middle of disc, complicated morphology of the aedeagus with the presense of very long flagellum, and somewhat similar shape of the female genital segment, Himalodromeus gen. n. is more similar to the genus Trichodromeus (see above). It can be distinguished from the latter genus by the following morphological features: 1) very large body, 2) bluish coloration of the elytra ( H. cyanipennis , H. grandis sp. n.), 3) significantly longer maxillary palpomeres, with the presence of the pubescence on maxillary palpomeres 2–3 (only preapical palpomere in Trichodromeus with dense pubescence) and elongate apical palpomere, distinctly longer than preapical segment ( Fig. 100 ), 4) the absence of the third median tooth on inner margin of left mandible ( Fig. 99 ), 5) significantly longer apical labial palpomere, about twice as long as two preceding segment, 6) narrower and longer basal antennomere ( Fig. 101 ), 7) distinctly broader pronotum and pronotal epipleura, with the presence of fine crenulation on the lateral margins ( Fig. 104 ), 8) the shape of the elytra more broadened posteriad ( Fig. 109 ), 9) the presence of extremely deep emargination of the posterior margin of the male abdominal sternite VIII ( Figs 117, 122–123 ), and 10) the external and internal morphology of the aedeagus, with strongly reduced parameres ( Figs 110, 112, 114 ). Also see the key to genera below.

Species of this genus are the largest omaliines in the Palaearctic Region. Larger species are known from the Nearctic Region in the genus Phlaeopterus , e.g. Ph. bakerensis Mullen & Campbell, 2018 (10.1 mm), see Mullen et al. (2019).

Key to species of Himalodromeus

1 Pronotum broader slightly in front of middle, with frontal part strongly protruded anteriad ( Fig. 96 ). Each elytron with distinct four narrow and elongate elevations in middle.Aedeagus as in Fig. 112 . Body dark-brown, with bluish elytra. Habitus as in Fig. 93 . Body length: 8.25–9.45 mm ............................................................... grandis sp. n.

- Pronotum broader in anterior portion, with frontal part not ( Fig. 97 ) or slightly protruded anteriad ( Fig. 95 ). Elytra without elevations. Coloration different.......................................................................... 2

2 Frontal part of pronotum slightly protruded anteriad ( Fig. 95 ). Body reddish-brown to dark-brown, with bluish elytra. Median lobe relatively narrow, with elongate sclerotized lateral lobes; parameres somewhat elongate, but not reaching middle of median lobe ( Fig. 110 ). Habitus as in Figs 90–91 . Body length: 6.00– 8.50 mm. India, Nepal........................ cyanipennis

- Frontal part of pronotum not protruded anteriad ( Fig. 97 ). Body reddish-brown. Median lobe very wide, without lateral lobes; parameres extremely short ( Fig. 114 ). Habitus as in Fig. 94 . Body length: 6.25–8.00 mm.................. reductus sp. n.

Species list

Figures

FIGURE 89. Distribution of Asiageodromicus in the Himalayan Region: A. crassipalpis (circles), A. dolpoensis (star), A. palpalis (Coiffait, 1977) (squares), A. spadiceus (triangles), A. weiperti sp. n. (diamonds)

FIGURE 124. Distribution of Himalodromeus: H. cyanipennis (circles), H. grandis (square), H. reductus (triangles).

FIGURES 66–67. Habitus of Asiageodromicus: 66—A. dolpoensis (holotype), 67—A. weiperti (paratype). Scale bar: 1.0 mm.

FIGURES 79–88. Aedeagus (Figs 79–82) and abdominal segments (Figs 83–88) of Asiageodromicus (Figs 79–80: A. weiperti (holotype); Figs 81–82; A. dolpoensis (holotype); Figs 83–88: A. crassipalpis): 79, 81—aedeagus, parameral view, 80, 82— aedeagus, lateral view, 83—male tergite VIII, 84—male sternite VIII, 85—male genital segment, 86—female tergite VIII, 87—female sternite VIII, 88—female genital segment. Scale bar: 0.1 mm.

FIGURES 90–97. Habitus (Figs 90–94) and apical part of pronotum (Figs 95–97) of Himalodromeus: 90—H. cyanipennis (Uttarakhand), 91, 95—H. cyanipennis (paratype), 92—Hygrogeus cyanipennis var. atrocaeruleus (lectotype), 93, 96—H. grandis (holotype), 94, 97—H. reductus (paratype). Scale bar: 1.0 mm.

FIGURES 98–109. Himalodromeus cyanipennis: 98—labrum (dorsal view), 99—mandibles (left and right, dorsal view), 100— maxilla (dorsal view), 101—labium (ventral view), 102—mentum (ventral view), 103—head (ventral view), 104—prothorax (ventral view), 105—mesoventrite (ventral view), 106—metaventrite (ventral view), 107—metendosternite (dorsal view), 108—scutellum (ventral view), 109—elytron (ventral view). Scale bar: 0.1 mm.

FIGURES 110–115. Aedeagus of Himalodromeus (Figs 110–111: H. cyanipennis (paralectotype), Figs 112–113: H. grandis (holotype), Figs 114–115: H. reductus (paratype): 110, 112, 114—parameral view, 111, 113, 115—lateral view. Scale bar: 0.1 mm.

FIGURES 116–123. Abdominal segments (ventral view) of Himalodromeus (Figs 116–121: H. cyanipennis; Fig. 122: H. grandis; Fig. 123: H. reductus): 116—male tergite VIII, 117, 122–123—male sternite VIII, 118—male genital segment, 119— female tergite VIII, 120—female sternite VIII, 121—female genital segment. Scale bar: 0.1 mm.