Trichodromeus kumaonensis ( Champion, 1925 )

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 : 22-24

Trichodromeus kumaonensis ( Champion, 1925)

( Figs 6 , 52–53 )

Hygrogeus kumaonensis Champion, 1925: 105 ; Cameron 1930: 166, Scheerpeltz 1933: 1067.

Hygrogeus kumaonensis var. breviusculus Champion, 1925: 105 ; Cameron 1930: 166, Scheerpeltz 1933: 1067.

Trichodromeus kumaonensis : Zerche 1992: 133, Herman 2001: 373, Smetana 2004: 252, Schülke & Smetana 2015: 326.

Type material examined. Holotype of Hygrogeus kumaonensis Champion, 1925 ♂ (left antennomeres 4–11 missing): ‘ ♂ ’ <printed>, ‘ SYN- | TYPE’ <round label with blue margin, printed>, ‘TYPE | H.T.’ <round label with red margin, printed>, ‘Shelshel, | N.Kumaon, India | 15750 ft. H.G.C.’ <printed>, ‘ Hygrogeus | kumaonensis | type 1925 Ch[ampion]’ <handwritten>, ‘ Hygrogeus | kumaonensis | Champ.’ <printed>, ‘E.M.M. 1925. | det. G. C. C.’ <printed>, ‘G.C.Champion | Brit. Mus. | 1925-42.’ <printed>, ‘ Trichodromeus | kumaonensis ( Champion, 1925) | Shavrin A.V. det. 2022’ ( BMNH). Paratypes: 2 ♀♀: ‘ ♀ ’ <printed>, other labels as the previous ( BMNH); 1 ♂: ‘ ♂ ’ <printed>, ‘ SYN- | TYPE’ <round label with blue margin, printed>, ‘Sangcha, | N. Kumaon, India. | 14500 ft. H.G.C.’ <printed>, ‘ Hygrogeus | kumaonensis, | Champ.’ <printed>, ‘G.C.Champion | Brit. Mus. | 1925-42.’ <printed>, ‘E.MM. 1925. | det. G.C.C.’ <printed> ( BMNH); 3 ♀♀: ‘ ♀ ’ <printed>, other labels as the previous ( BMNH); 1 ♀: ‘ ♀ ’ <printed>, ‘ SYN- | TYPE’ <round label with blue margin, printed>, ‘Shelshel, | N.Kumaon, India | 15750 ft. H.H.C.’ <printed>, ‘E.MM. 1925. | det. G.C.C.’ <printed>, ‘G.C.Champion | Brit. Mus. | 1925-42.’ <printed>, ‘ Hygrogeus | kumaonensis, | Champ.’ <printed>. All paratypes with additional printed label: ‘ Trichodromeus | kumaonensis ( Champion, 1925) | Shavrin A.V. det. 2022’.

Holotype of Hygrogeus kumaonensis var. breviusculus Champion, 1925 ♂ (dissected): ‘ ♂ ’ <printed>, ‘ SYN- |TYPE’ <round label with blue margin, printed>, ‘TYPE | H.T.’ <round label with red margin, printed>, ‘Laptel, | N. Kumaon, India. | 15,000 ft. H.G.C.’ <printed>, ‘ Hygrogeus | kumaonensis | v. breviusulcus | 1925 Ch’ <handwritten>, ‘ Hygrogeus | kumanoensis, | v. breviusulcus, Ch. ’ <printed>, ‘E.M.M. 1925. | det. G. C. C.’ <printed>, ‘G.C.Champion | Brit. Mus. | 1925-42.’ <printed> ( BMNH). Paratypes: 2 ♂♂: ‘ ♂ ’ <printed>, ‘ SYN- | TYPE’ <round label with blue margin, printed>, ‘Laptel, | N. Kumaon, India. | 15,000 ft. H.G.C.’ <printed>, ‘ Hygrogeus | kumaonensis | v. breviusulcus | 1925 Ch’ <handwritten>, ‘ Hygrogeus | kumaonensis, | v. breviusulcus, Ch. ’ <printed>, ‘G.C.Champion | Brit. Mus. | 1925-42.’ <printed> ( BMNH). All paratypes with additional printed label: ‘ Trichodromeus | kumaonensis ( Champion, 1925) | Shavrin A.V. det. 2022’.

Redescription. Measurements (n=11): HW: 1.04–1.24; HL: 0.71–0.87; OL: 0.28–0.30; TL: 0.25–0.27; AL (holotype): 3.50; PL: 1.07–1.16; PWmax: 1.32–1.47; PWmin: 0.95–1.03; ESL: 1.78–1.99; EW: 1.84–2.08; MTbL (holotype): 1.37; MTrL (holotype): 0.59 (MTrL 1–4: 0.32; MTrL 5: 0.27); AW: 1.78–1.93; AedL (holotype): 1.02; BL: 5.60–7.60 (holotype: 6.15).

Habitus as in Fig. 6 . Body dark-brown, with paler elytra in some paratypes; mouthparts, legs and antennae yellow-brown to brown; tarsi yellowish. Head with dense transverse microsculpture, finer in middle; pronotum with dense microreticulation, finer in middle and/or mediobasal portion; scutellum with dense transverse and fine meshes; abdominal tergites with dense, isodiametric or transverse microreticulation.

Head 1.4 times as broad as long, with distinctly convex supra-antennal elevations, middle portion between anterior margins of eyes and infraorbital portions, with deep and moderately narrow anterio-median depression narrowed toward subtrapezoidal and moderately deep interocellar depression; temples convex, slightly shorter than longitudinal length of eyes; interocellar depression separated from infraorbital portions by narrow and moderately deep strongly convergent latero-anteriad anteocellar foveae, reaching level of apical third of eyes. Ocelli small, but distinct, located slightly below level of posterior margins of eyes, distance between ocelli slightly more than twice as long as distance between ocellus and posterior margin of eye. Punctation fine, sparse and sometimes indistinct in middle between interocellar foveae or moderately large, deep and dense on infraorbital portions. Last maxillary palpomere about 1.2 times as long as preceding segment, from apical third gradually narrowed toward subacute apex. Antenna reaching or exceeding middle length of elytra; basal antennomere robust, antennomere 3 distinctly longer than 2, 4–8 slightly shorter than 3, 9–10 indistinctly broader than 8, apical antennomere 1.2–1.4 times as long 10.

Pronotum 1.2 times as broad as long, from widest anterior portion gradually narrowed posteriad toward obtuse or rounded hind angles; frontal portion slightly or distinctly protruded anteriad, with anterior margin widely rounded, distinctly shorter than straight posterior margin; middle portion with moderately deep and long longitudinal depression stretching from about medio-apical part and reaching middle or mediobasal portions; basal part of pronotum narrowly and moderately deeply depressed. Punctation about as that on head, but denser, with distance between punctures in middle about as long as diameters of nearest one-four punctures, some specimens with distinctly sparser and finer punctation in/or middle and mediobasal portions. Scutellum large, with a few fine punctures.

Elytra moderately convex, slightly broader than long and slightly broadened posteriad, 1.6–1.7 times as long as pronotum; lateral margins narrowly flattened and slightly reflexed in latero-apical portions; hind margins widely rounded. Punctation dense, about as that on pronotum, but slightly larger and deeper, usually finer along suture.

Abdomen slightly narrower than elytra, abdominal tergite IV with two moderately large and transverse tomentose spots, abdominal tergite V with two small, oval spots.

Male. Pronotum slightly more trasverse and more convex. Apical margin of abdominal tergite VIII slightly and sternite VIII widely concave. Basal part of aedeagus wide, strongly narrowed toward elongate and narrow median lobe, widened about middle and from apical third strongly narrowed toward subacute apex; parameres narrow, indistinctly broadened apically, slightly not exceeding apex of median lobe, with three moderately short apical setae; internal sac narrow, moderately long, with two fields of small sclerotized spines and long flagellum, spirally folded in basal portion ( Fig. 52 ). Lateral aspect of the aedeagus as in Fig. 53 .

Female. Pronotum less transverse and less convex. Apical margin of abdominal tergite VIII and sternite VIII rounded.

Comparative notes. Based on the general shape of the body, T. kumaonensis is similar to T. alticola and T. sulcicollis , both described from Kashmir, and T. meurguesae , known from Afghanistan. It can be distinguished from all these species by the following morphological features:

from T. alticola by the somewhat broader body, shorter antennae and finer punctation of the elytra;

from T. meurguesae by the paler coloration of the body, the shorter elytra and the completely different shape of the aedeagus (compare Fig. 44 and Fig. 4H in Coiffait (1979));

from T. sulcicollis by the finer sculpture of the longer pronotum, less narowed basad and the narrower elytra.

Distribution. Trichodromeus kumaonensis is known from Pakistan and India (Uttarakhand).

Bionomics. Specimens were collected at elevations from 3200 to 4800 m a.s.l. Detailed bionomical data are unknown.

Remarks. Hygrogeus kumaonensis was originally described from “Shelshel, alt. 15,750 ft. [type], Sangcha, alt. 14,500 ft., and Laptel, alt. 15,000 ft., all in N Kumaon…” based on two males and twelve females. In the same description, Champion (1925) described H. kumaonensis var. breviusculus . Later, Cameron (1930) redescribed both taxa. Coiffait (1983) recorded it from “Himachal Pradesh, Mari, 3 500 m …”, but the figure of the aedeagus (fig. 2H in Coiffait (1983)) is not conspecific with the aedeagus studied by me and belong to other species of Trichodromeus . Zerche (1992) transferred Hygrogeus kumaonensis to Trichodromeus and recorded it from Pakistan. I`m studied the holotype and four paratypes of H. kumaonensis and the holotype and two paratypes of H. kumaonensis var. breviusculus . Based on details of the external morphology, both taxa are conspecific. Besides that, aedeagi both H. kumaonensis and H. var. breviusculus are conspecific too. Here I redescribe this species and provide illustrations of the habitus and the aedeagus for the first time.

Figures

FIGURES 1–6. Habitus of Hygrogeus (Fig. 1) and Trichodromeus (Figs 2–6): 1—H. aemulus (Tirol), 2—T. armatus (Kashmir: Baltal), 3—T. armatus (Kashmir: Kolahoi Glacier), 4—T. ketmeniensis (Kyrgyzstan: Chatkal Mts.), 5—T. ovchinnikovi (holotype), 6—T. kumaonensis (paratype). Scale bar: 1.0 mm.

FIGURES 52–58. Aedeagus of Trichodromeus (Figs 52–53: T. kumaonensis (paratype), Figs 54–55: T. telnovi (holotype), Figs 56–58: T. penicillatus (Figs 56–57: Kazakhstan, Dzhabagly; Fig. 58: Kyrgyzstan, Chakmak): 52, 54, 56, 58—parameral view, 53, 55, 57—lateral view. Scale bar: 0.1 mm.

FIGURES 39–46. Aedeagus of Trichodromeus (Figs 39–40: T. armatus (Kashmir: Kolahoi Glacier), Figs 41–42: T. jaegeri (Nepal: Gandaki), Figs 43–46: T. ketmeniensis (Figs 43–44: Kazakhstan, Kulbastau), Fig. 45: Kyrgyzstan, Sary-Chelek, Fig. 46: Kazakhstan, Dolaity): 39, 42, 43, 45–46—parameral view, 40, 42, 44—lateral view. Scale bar: 0.1 mm.