Anthobium curtulum, Shavrin, 2025

Shavrin, Alexey V., 2025, A revision of eastern Palaearctic Anthobium Leach, 1819 (Coleoptera: Staphylinidae: Omaliinae: Anthophagini). IX. Thirteen new species and records from China and the Himalayan Region, Zootaxa 5728 (1), pp. 47-78 : 73-75

Anthobium curtulum sp. nov.

( Figs 35 , 37 , 42, 43 )

Type material. Holotype ♂ ( Fig. 35 ; dissected; right metatibia and metatarsus missing): NEPAL: ‘NEPAL (Prov. Bagmati) | Yangri Ridge | 4450 m, 23.IV.81 | Löbl & Smetana’ <printed>, ‘ HOLOTYPE | Anthobium | curtulum sp. nov. | Shavrin A.V. des. 2025’ <red, printed> ( CNC).

Description. Measurements: HL: 0.37; HW: 0.70; AL: 1.47; OL: 0.22; LT: 0.07; PL: 0.62; PW: 1.18; ESL:

1.47; EW: 1.65; AW: 1.37; MTbL: 0.75; MTrL: 0.43 (MTrL 1–4: 0.28; MTrL 5: 0.15); AedL: 0.37; BL: 3.80.

Habitus as in Fig. 35 . Body brown, with slightly darker head; mouthparts, antennomeres and legs yellow-brown (antennomeres 7–11 slightly darker). Forebody without microreticulation except of basal portion of neck and apical part of visible portion of scutellum with fine transverse microreticulation. Head with fine and sparse punctation, slightly denser in middle and slightly larger on infraorbital portions; neck with regular, sparse and fine punctation; pronotum with sparse and fine punctation, slightly larger in lateral and sparser in middle portions, mediobasal third without punctures; apical part of scutellum with several fine punctures; punctation of elytra significantly denser, larger and deeper than that on pronotum, finer in mediobasal and medioapical portions, distance between punctures in middle about as long as diameter of one-three nearest punctures, each elytron not forming longitudinal rows of punctures; abdominal tergites with indistinct, fine and sparse punctation.

Head with distinctly elevated middle and infraorbital portions, 1.8 times as broad as long; anteriomedian depressions indistinct; anteocellar foveae straight and moderately deep, reaching level of about middle length of eyes. Ocelli located slightly below level of postocular ridges.Apical maxillary palpomere about two and a half times as long as preceding segment. Antennomere 3 about as long as and distinctly narrower than 2, 4–6 distinctly shorter than 3, 7–8 slightly broader than 6, 9–10 slightly broader than 8, apical antennomere 1.4 times as long as 10.

Pronotum 1.9 times as broad as long, from widest middle gradually narrowed both anteriad and posteriad; posterior angles widely rounded; anterior angles widely rounded, strongly protruded anteriad; anterior margin somewhat straight; mediobasal portion with large and deep semicircular depression; lateral portions widely impressed and distinctly explanate, each with deep oval impression slightly above middle; lateral edges without crenulation.

Elytra 1.1 times as broad as long, reaching apical margin of abdominal tergite IV; middle part of each elytron with distinct transverse and longitudinal elevations between punctures; latero-apical edges slightly crenulated.

Metatarsi distinctly less than twice as long as metatibia.

Abdominal tergite V with a pair of small rounded tomentose spots in middle.

Male. Posterior margin of abdominal tergite VIII straight. Posterior margin of abdominal sternite VIII sinuate. Aedeagus with wide basal part, gradually narrowed toward wide and truncate apex; parameres significantly longer than apex of median lobe, slightly broadened in preapical portions, each with one short apical and two preapical setae; internal sac long and wide, spirally folded in basal part ( Fig. 42 ). Lateral aspect of the aedeagus as in Fig. 43 .

Female unknown.

Comparative notes. Based on the general shape of the body and the shape of the pronotum with anterior angles distinctly protruded anteriad, A. curtulum sp. nov. is similar to Siberian A. frigidum (J. Sahlberg, 1880) , Chinese A. sinicum sp. nov. (see below) and Middle Asian A. tichomirovae Shavrin, 2022 , recently described from Tajikistan ( Shavrin 2022a). It can be distinguished from them by the following morphological features:

from A. frigidum by the anterior angles of the pronotum distinctly more protruded anteriad and the narrower apical portions of the parameres;

from A. sinicum sp. nov. by the larger body with darker coloration, longer antennomeres 4–10, slightly broader elytra, significantly broader apical part of the median lobe, and longer parameres;

from A. tichomirovae by the smaller body with paler coloration, slightly longer antennomeres 9–10, the anterior angles of the pronotum distinctly more protruded anteriad, broader median lobe and narrower apical portions of the parameres.

From all these species it can be distinguished by the the finer and sparser punctation of the narrower pronotum with the presence of deep mediobasal depression, and details of morphology of the aedeagus.

Distribution. Anthobium curtulum sp. nov. is known only from the type locality in Bagmati, Nepal ( Fig. 37 ).

Bionomics. The specimen was collected at an elevation 4450 m a.s.l. together with A. aterrimum sp. nov. and A. sculpturatum sp. nov. The detailed bionomical data are unknown.

Etymology. The specific epithet is the Latin adjective curtulus, - a, - um (short and small). It refers to the shape of the pronotum.

Figures

FIGURE 37. Distribution of Anthobium kleebergi (circles), A. lakshmanai (square) and A. curtulum (triangle) in Nepal.

FIGURES 33–36. Habitus of Anthobium: 33–34—A. kleebergi (Fig. 33: paratype: Nepal, Annapurna Mts., Fig. 34: paratype: Nepal, Nyimare), 35—A. curtulum (holotype), 36—A. sinicum (holotype). Scale bar: 1.0 mm.

FIGURES 38–43. Aedeagus of Anthobium (Figs 38–39—A. lakshmanai (holotype), Figs 40–41—A. portentum (holotype), 42– 43—A. curtulum (holotype)): 38, 40, 42—aedeagus, parameral view, 39, 41, 43—aedeagus, lateral view. Scale bar: 0.1 mm.