Anthobium infractum, Shavrin, 2022

Shavrin, Alexey V., 2022, A revision of Palaearctic Anthobium Leach, 1819 (Coleoptera: Staphylinidae Omaliinae: Anthophagini). V. Algidum, morosum and tectum groups, a new species of the fusculum group, and faunistic records, Zootaxa 5104 (3), pp. 301-346 : 339-341

Anthobium infractum sp. n.

( Figs. 93 , 98 , 105–106 )

Type material examined: Holotype ♂ [dissected]: ‘ INDIA W. Bengal | Darjeeling distr. | Tonglu 3100m 16.X. | [C.]Besuchet-[I.] Löbl [19]78’ <printed>, ‘HOLOTYPE | Anthobium | infractum sp. n. | Shavrin A.V. des. 2022’ <red, printed> ( MHNG).

Description. Measurements: HW: 0.55; HL: 0.31; AL: 0.95; OL: 0.12; PL: 0.42; PW: 0.82; ESL: 1.05; EW: 1.05; AW: 0.80; MTbL: 0.50; MTrL: 0.25 (MTrL 1–4: 0.15; MTrL 5: 0.10); AedL: 0.30; TL: 2.25.

Body suboval, convex ( Fig. 98 ). Body and antennomeres 5–11 yellow-brown (head slightly darker); mouthparts, antennomeres 1–4 and legs yellow. Body without microsculpture except of portions between antennal bases and anterior margins of eyes with fine diagonal meshes and abdomen with distinct transverse microretilulation. Head with irregualr, moderately large and deep punctation, sparser in middle, denser on infraorbital ridges; neck with moderately dense punctation similar to that in middle of head; pronotum with very dense punctation, slightly coarser than that on head, sparser and finer in middle and mediobasal third; punctation of elytra slightly sparser than that on pronotum, coarser and deeper in middle and apical portions, finer in parascutellar portions and along suture, on each elytron forming very tangled and vague five longitudinal rows of punctures; abdominal tergites without visible punctation.

Head 1.7 times as broad as long, slightly elevated in middle, lateroapical portions between antennal insertion and apical margin of eyes deeply and mediobasal portions between ocelli and posterior margins of eyes slightly impressed; anteocellar foveae indistinct, very short, reaching level of posterior third length of eye; postocular ridge indistinct, smooth; anterior margin between antennal insertion and anterior margin of eye with wide and moderately deep semicircular notch. Ocelli moderately large, situated at about level of postocular ridges; distance between ocelli about 1.3 times as long as distance between ocellus and posterior margin of eye. Apical segment of maxillary palpomere distinctly more than twice as long as preceding segment, from basal third gradually narrowed toward subacute apex. Basal antennomere about twice as long as broad, antennomere 2 slightly narrower and 1.4 times as long as basal antennomere, 3 distinctly narrower than 2, 4 shorter than 3, 5–6 slightly longer than 4, 7–8 slightly shorter than 6, 9–10 slightly broader than 8, apical antennomere about 1.4 times as long as preapical antennomere, from apical third gradually narrowed toward subacute apex.

Pronotum slightly less than twice as broad as long, 1.4 times as broad as head, widest in middle, distinctly more narrowed posteriad than anteriad; apical margin widely rounded, distinctly protruded anteriad; anterior margin widely rounded, slightly shorter than basal margin; middle portion strongly elevated, with indistinct, wide, transverse impressions in mediobasal third; lateral margins with fine smooth crenulation, indistinct latero-basally; lateral portions strongly impressed, with deep oval pit in front of middle.

Elytra as long as broad, distinctly more than twice as long as pronotum, reaching middle of abdominal tergite V, with rounded apical margins; latero-apical and median margins with fine crenulation; surface between punctures in middle and preapical portions with indistinct elevations.

Meso- and metatibiae with fine and sparse spines on inner and outer edges; metatarsus twice as long as metatibia.

Abdomen distinctly narrower than elytra, with a pair of small and transverse wing-folding spots in middle of tergite V.

Male. Apical margins of abdominal tergite VIII and sternite VIII slightly sinuate. Aedeagus small, narrow, with widely rounded apex; parameres wide, significantly exceeding apex of median lobe, from apical third slightly narrowed toward curved apical portions, with two moderately short apical and two preapical setae situated at inner margin of each paramere; internal sac (apically inflated and curved in holotype) short and narrow ( Fig. 105 ). Lateral aspect of aedeagus as in Fig. 106 .

Female unknown.

Comparative notes. Regarding the general shapes of the pronotum and the elytra, very short anteocellar foveae, and indistinct elevations between punctures on each elytron, A. infractum sp. n. is similar to the Chinese A. splendidulum Shavrin & Smetana, 2018 (Yunnan) . From this species it is distinguished by the smaller body, denser and coarser punctation of the pronotum, slightly shorter antennomeres 4–10, and the completely different morphology of the aedeagus. Anthobium infractum sp. n. differs from all the species of the fusculum group by the narrow aedeagus and the significantly curved parameres.

Distribution. The species is known only from the type locality in West Bengal, India ( Fig. 93 ).

Natural history. The specimen was collected at an elevation of 3100 m a.s.l. Detailed ecological data are unknown.

Etymology. The specific epithet is the past participle of the Latin verb infringere (to fold, to break). It refers to the curved apical portions of the parameres.

Figures

FIGURE 93. Distribution of Anthobium in China and Nepal: A. cornatipenis (black circle), A. himalayense (black star), A. infractum (white square), A. morosum (white star), A. multipunctatum (white circle), A. smetanai (black square), A. umbrinum (black triangle), A. vitreum (black diamond).

FIGURES 94–98. Habitus of species of the Anthobium tectum group: 94—A. smetanai (holotype), 95—A. tichomirovae (holotype), 96—A. umbrinum (holotype), 97—A. vitreum (holotype), 98—A. infractum (holotype). Scale bar: 1.0 mm.

FIGURES 105–106.Aedeagus of Anthobium infractum (holotype): 105—parameral view, 106—lateral view. Scale bar: 0.1 mm.