Hygrodromicus incrassatus, Shavrin, 2024

Shavrin, Alexey V., 2024, On some species of the genus Hygrodromicus Tronquet with description of a new species from Pakistan (Coleoptera: Staphylinidae: Omaliinae: Anthophagini), Zootaxa 5481 (3), pp. 384-390 : 385-387

Hygrodromicus incrassatus sp. n.

( Figs 1 , 3–4 , 7 )

Type material examined. Holotype ♂ (a plastic plate with the aedeagus in Canada balsam was pinned under the card with the beetle; abdominal tergite VIII, sternite VIII, and the apical segment are glued on the same card under the specimen): ‘ PAKISTAN: NW Frontier | province, Kaghan valley, nr. | Sighban, 2200 m, | 20.VIII.2004, leg. V. Gurko’ <printed>, ‘Museum für Naturkunde | Berlin | Sammlung M. Schülke’ <printed>, ‘ HOLOTYPE | Hygrodromicus | incrassatus sp. n. | Shavrin A. V. des. 2024’ <red, printed> (cSch).

Paratypes: 2 ♀♀ ( Fig. 1 ; one specimen without right fore leg): same data as the holotype, with additional red printed label: ‘ PARATYPE | Hygrodromicus | incrassatus sp. n. | Shavrin A. V. des. 2024’ (cSch, cSh).

Description. Measurements (n = 3): HW: 1.05–1.10; HL: 0.70–0.73; OL: 0.12–0.14; LT: 0.10–0.13; AL (holotype): 4.15; PL: 0.92–1.05; PWmax: 1.26–1.45; PWmin: 1.03–1.20; ESL: 1.52–1.85; EW: 1.94–2.30; MTbL(holotype): 1.55; MTrL (holotype): 0.57 (MTrL 1–4: 0.32; MTrL 5: 0.25); AW: 2.24–2.40; AedL: 1.25; BL: 5.90–6.75 (holotype: 5.92).

Habitus as in Fig. 1 . Body reddish-brown (elytra of holotype distinctly paler); mouthparts, antennae and legs brownish; apical segment of maxillary palpi and tarsi yellowish. Head with regular, dense and fine isodiametric microreticulation, coarser in middle portion; neck with isodiametric sculpture, denser and coarser than that in middle portion of head; pronotum with dense isodiametric microsculpture similar to that in head, finer in middle; scutellum with dense transverse meshes in middle; abdomen with dense and moderately fine transverse microreticulation.

Head 1.5 times as broad as long, with markedly elevated portion between anterior margins of eyes and infraorbital portions; supra-antennal protuberances moderately wide and distinctly elevated; medioapical depression deep and wide, narrowing posteriad and indistinctly connected with moderately deep subrectangular interocellar depression; anteocellar foveae narrow and long, deep, convergent diagonally toward level of anterior margins of eyes; temples convex and slightly shorter than longitudinal length of eyes. Eyes moderately small, strongly convex. Punctation dense and moderately fine, sparser and finer in middle. Ocelli small, located distinctly below level of posterior margins of eyes, distance between ocelli slightly longer than distance between ocellus and posterior margin of eyes. Apical segment of maxillary palpi short, about three times shorter than preapical segment. Antenna long, almost reaching apical margins of elytra when reclined; basal antennomere distinctly more than three times as long as broad, antennomere 2 narrower and significantly shorter than basal antennomere, 3 distinctly longer than 2, 4–5 slightly longer than 3, 6–9 indistinctly longer and broader than 5, 10 slightly shorter than 9, apical antennomere about 1.3 times as long as 10.

Pronotum moderately convex, 1.3 times as broad as long, 1.2–1.3 times as broad as head, widest in anterior portion, strongly narrowed posteriad toward obtuse posterior angles, with indistinctly elevated longitudinal band in middle (holotype); posterior margin rounded, about as long as posterior margin slightly concave in middle.Punctation about as that in middle portion of head, but distinctly denser, sparser in median part, with narrow impunctate portion in middle. Scutellum with several fine and sparse punctation.

Elytra flattened, 1.2 times as broad as long, 1.6–1.7 times as long as pronotum, strongly broadened posteriad, with straight or widely rounded apical margins. Punctation dense, distinctly larger and deeper than that on pronotum, denser and finer around scutellum, with interstices between punctures in middle about as long as diameter of one-two nearest puncture; paratypes with finer and sparser punctation along suture. Hind wings fully developed.

Abdomen distinctly broader than elytra, with two small and transverse tomentose spots in the middle of abdominal tergite V; apical margin of abdominal tergite VII with narrow palisade fringe. Punctation dense and fine.

Male. Protarsomeres 1–4 wide. Apical portion of pronotum wide. Apical margin of abdominal tergite VIII somewhat straight. Apical margin of abdominal sternite VIII sinuate. Aedeagus with small narrow basal portion and elongate moderately wide median lobe, strongly narrowed in apical third, slightly broadened in preapical portion and narrowed toward rounded apex; parameres narrow, almost reaching apex of median lobe, each with four short apical setae; internal sac moderately long with two pairs of narrow elongate sclerotized structures and long narrow flagellum between them, spirally folded in basal portion ( Fig. 3 ). Lateral aspect of the aedeagus as in Fig. 4 .

Female. Protarsomeres 1–4 moderately narrow. Apical portion of pronotum relatively narrow. Apical margins of abdominal tergite VIII straight. Apical margin of abdominal sternite VIII somewhat rounded.

Comparative notes. Based on the general shape of the body and the aedeagus, H. incrassatus sp. n. is similar to H. wrasei Zerche, 1992 , known from Tajikistan ( Zerche 1992, Shavrin 2024). It can be distinguished from it by the larger body, the presence of ocelli, longer antennomeres 6–10, more transverse pronotum (especially in male) with more narrowed laterobasal margins, longer median lobe of the aedeagus with different shape of the apical portion, and the presence of the flagellum (missing in H. wrasei ). Based on the general shape of the aedeagus, H. incrassatus sp. n. is also similar to H. cachemiricum Coiffait, 1983 ( India: Kashmir), H. klapperichi Coiffait, 1982 ( Afghanistan), and Middle Asian H. reitteri (Scheerpeltz, 1933) and H. splendidus . It can be distinguished from these species by the following morphological features: from H. cachemiricus by the broader pronotum, narrower and longer median lobe, with shorter apical portion; from H. klapperichi and H. reitteri by the distinctly broader pronotum and elytra, shorter median lobe with different shape of the apical portion; from H. splendidus by narrower antennae and the less convex pronotum, the longer parameres and different shape of the apical portion of the median lobe. From all these species H. incrassatus sp. n. can be distinguished by the details of the internal structure of the aedeagus.

Distribution. Hygrodromicus incrassatus sp. n. is known only from the type locality in northern Pakistan ( Fig. 7 ).

Bionomics. The type specimens were collected at an elevation of 2200 m a.s.l. The detailed bionomical data remains unknown.

Etymology. The specific epithet is the Latin incrassatus , - a, - um (thickened). It alludes to the wide pronotum of the male.

Figures

FIGURE 7. Distribution of Hygrodromicus incrassatus (square) and H. splendidus (circles).

FIGURES 1–2. Habitus of Hygrodromicus: 1–H. incrassatus (paratype), 2–H. splendidus (Kazakhstan, Ketmen` Mts.). Scale bar: 1.0 mm.

FIGURES 3–6. Aedeagus of Hygrodromicus (Figs 3–4: H. incrassatus (holotype); Figs. 5–6: H. splendidus (Kazakhstan: Ketmen` Mts.): 3, 5–parameral view, 4, 6–lateral view. Scale bars: 0.1 mm.