Microhygrodromicus politus, 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 : 57-59

Microhygrodromicus politus sp. n.

( Figs 126 , 136–141 )

Type material examined. Holotype ♂ ( Fig. 126 ; dissected): ‘ CHINA: YUNNAN PROv. | Gongshan Co., Biluo Mts. | Pass.; mixed forest and alpine | meadows; 5.–8.vii.2019 | 28°04.7’N, 98°45.6’E, 3890m | Hájek, Hrůzová, Král, Růžička & Sommer lgt.’ <printed>, ‘ HOLOTYPE | Microhygrodromicus | politus sp. n. | Shavrin A.V. des. 2024’ <red, printed> ( NMPC).

Description. Measurements: HW: 0.60; HL: 0.51; OL: 0.20; LT: 0.10; AL: 0.00; PL: 0.68; PWmax: 0.72; PWmin: 0.52; ESL: 1.11; EW: 1.17; MTbL: 0.87; MTrL (holotype): 0.31 (MTrL 1–4: 0.16; MTrL 5: 0.15); AW: 1.19; AedL: 0.85; BL: 3.70.

Habitus as in Fig. 126 . Body shiny; forebody dark-brown, with black abdomen; antennae, maxillary palpomeres 3–4, femori and tarsi brown; mouthparts and tibiae yellow-brown. Forebody without microsculpture except of apical portion of clypeus with sparse transverse reticulation, neck with fine transverse meshes and abdomen with indistinct transverse microsculpture. Pubescence fine and sparse, suberect, denser and longer on elytra and abdomen.

Head 1.1 times as broad as long, with distinctly elevated middle portion between anterior margins of eyes and infraorbital portion; anterio-median depression wide and deep; interocellar depression wide and moderately deep, subtriangular, from widest middle part at level of anterior third of eyes narrowed posteriad toward neck; anteocellar foveae long and deep, convergent latero-anteriad toward level of anterior third of eyes. Temples convex, twice shorter than longitudinal length of eyes. Distance between ocelli 1.8 times as long as distance between ocellus and eyes. Punctation irregular, sparser and finer in middle and denser between ocelli; neck with fine and sparse punctation. Last maxillary palpomere about as long as penultimate segment. Antennomere 3 slightly longer than 2, 4 slightly shorter than 3, 5–7 indistinctly broader and distinctly longer than 3, 8–9 slightly longer and broader than 7, 10 slightly shorter than 9, apical antennomere 1.6 times as long as 10.

Pronotum moderately wide in apical portion, slightly broader than long and distinctly broader than head, from widest anterior portion strongly narrowed posteriad toward obtuse posterior angles; lateral margins narrowly bordered, without crenulation; mediobasal portion in front of basal margin with moderately deep oval depression; laterobasal portions slightly and widely depressed. Punctation dense and deep, significantly larger than that in middle portion of head, sparser in medioapical portion, with narrow impunctated area in front of mediobasal part. Scutellum with fine and sparse punctation.

Elytra slightly depressed in middle, 1.6 times as long as pronotum. Punctation dense, slightly larger and deeper than that on pronotum, denser and finer around scutellum, and finer and sparser along suture.

Metatarsus distinctly more than twice shorter than metatibiae; apical metatarsomere slightly shorter than preceding four metatarsomeres.

Abdomen broader than elytra. Punctation sparse and fine, sparser in middle portions of abdominal tergites V–VIII.

Male. Posterior margin of abdominal tergite VIII straight ( Fig. 139 ). Posterior margin of abdominal sternite VIII widely concave ( Fig. 140 ). Genital segment as in Fig. 138 . Aedeagus with wide basal portion, narrowed toward median lobe; median lobe gradually narrowed in apical third, with moderately wide apical portion, from middle narrowed toward subacute apex; parameres narrow, disinctly shorter than median lobe, with two long and two short apical setae; internal sac with several elongate sclerotized structures in about middle and preapical portion, with very long flagellum, spirally folded in basal portion ( Fig. 136 ). Lateral aspect of the aedeagus as in Fig. 137 .

Female unknown.

Comparative notes. Microhygrodromicus politus sp. n. can be distingushed from M. exiguus sp. n. by the larger body, darker abdomen, distinctly finer punctation of the head, longer temples not protruded posteriad, relatively broader apical part of the pronotum without lateral crenulation and with distinctly depressed mediobasal part, shorter elytra, shape of the elongate apical part of the median lobe narrowed toward subacute apex, and other details of the morphology of the aedeagus.

Distribution. The species is known only from the type locality in Biluo Mts., Yunnan, China ( Fig. 141 ).

Bionomics. The holotype was collected between mixed forest and alpine meadow at an elevation of 3890 m a.s.l.

Etymology. The specific epithet is the Latin adjective politus , - a, - um (shiny). It alludes to the shiny forebody.

Figures

FIGURE 141. Distribution of Microhygrodromicus exiguus (circle) and M. politus (square) in Yunnan, China.

FIGURES 125–126. Habitus of Microhygrodromicus: 125—M. exiguus (holotype), 126—M. politus (holotype). Scale bar: 1.0 mm.

FIGURES 136–140. Microhygrodromicus politus: 136—aedeagus, parameral view, 137—aedeagus, lateral view, 138—male genital segment, 139—male tergite VIII, 140—male sternite VIII. Scale bars: 0.1 mm.