Anthobiomorphus Shavrin & Smetana, 2020

Shavrin, Alexey V. & Smetana, Aleš, 2020, Anthobiomorphus, a new genus of Anthophagini Thomson, 1859 (Coleoptera: Staphylinidae: Omaliinae), with description of two new species from China, India and Nepal, Zootaxa 4755 (3), pp. 576-586 : 577-578

Anthobiomorphus Shavrin & Smetana , gen. nov.

Type species: Anthobiomorpus rougemonti Shavrin & Smetana , sp.nov.

Description. Body elongate ( Figs. 1–2 ), convex, shiny, reddish-brown to black. Head and pronotum with irregular, sparse punctation; punctation of elytra coarser, denser and deeper than that on pronotum, on each elytron forming indistinct, vague and tangled six to seven rows of punctures; abdomen without visible punctation. Body without microsculpture except anterior portion of head with distinct microreticulation and abdomen with very fine transverse microsculpture. Body glabrous; clypeus with several long setae and frons with several short, semi-erect setae; disc of pronotum with very sparse, short, erect setae, lateral edges of pronotum with sparse and very short setae; medial portion of elytra with sparse semi-erect setation; abdominal tergites with very small setae.

Head transverse, with slightly elevated supra-antennal prominences and middle portion; grooves (dorsal tentorial pits) in front of ocelli deep and long; mediobasal portion of head with deep narrow impression between ocelli; postocular ridges distinct, acute, with surface between postocular ridge and posterior margin of eye gradually widened laterad; anterior portion of head between antennal insertion and anterior margin of eye with distinct semicircular notch. Ocelli large, convex. Eyes large, strongly convex. Gular sutures narrowly separated at level of posterior third of eyes, strongly divergent posteriorly towards base of head. Labrum small, transverse, with widely rounded latero-apical portions, shallow apical emargination and elongate laterobasal projections (internaly, under the clypeus) ( Fig. 3 ). Mandibles moderately narrow, each with narrow, elongate apical portion, wide and large prostheca, small mola, and moderately large rounded tooth in about middle of right mandible ( Fig. 4 ). Mentum small, with numerous long setae; labium moderately narrow, with slightly trapezoidal preapical labial palpomere, apical palpomere slightly wider than preceding one; basal portion of palpiger narrow; apical margin of moderately wide glossa irregularly dissected into several narrow parts, each rounded apically ( Fig. 5 ). Maxilla as in Fig. 6 ; preapical palpomere of maxillary palp short, about as long as wide; apical palpomere three to four times as long as preceding, galea broadly and deeply divided into two elongate lobes ( Figs. 6–7 ); lacinia moderately wide, with unarticulated spine-like apex and numerous setae along medial margin. Antenna long, exceeding basal third of elytra when reclined, with antennomeres 3–10 elongate and progressively widened apically; antennomeres 3–11 covered by dense pubescence.

Pronotum distinctly transverse, convex in medioapical portion or in middle and slightly convex in laterobasal portions between lateral margin and middle impression; pronotum widest at about anterior third, from middle indistinctly or distinctly narrowed anteriad and markedly narrowed posteriad; latero-apical angles widely rounded and protruding anteriad; posterior angles acute; lateral edges with irregular crenulation, with one or two irregular, moderately large or somewhat smooth protrusions before sharply narrowed and straight laterobasal emargination; mediobasal portion with wide and very deep semicircular impression, distinctly connected with deep lateral pits; lateral portions wide and markedly explanate. Prothorax with moderately short intercoxal process and strongly protruding, wide prosternal processes. Mesoventrite short, with long intercoxal process reaching middle of mesocoxae. Scutellum large, widely triangular, with moderately deep, wide impression in middle. Metaventrite with wide, deep intercoxal cavities and elongate anterior intercoxal process reaching mesosternal process.

Elytra slightly longer than wide, markedly more than twice as long as pronotum, very convex (especially in medioapical third, if seen laterally); humeri widely rounded, not protruding anteriad; lateral portions flattened, distinctly widened in middle, with bordered margins; mediobasal portion of each elytron with very indistinct two or three irregular longitudinal elevations between punctures. Wings fully developed.

Legs moderately long and slender; tibiae without peg setae, covered by elongate setae, distinctly stronger and denser in mesotibiae, apical margins near apex of all tibiae with a few strong spines; metatarsus about twice as long as metatibia; apical metatarsomere as long as two or three preceding tarsomeres together.

Abdomen significantly narrower than elytra, very convex, with pair of rounded, moderately small wing-folding spots in middle of tergite V, with distinct, narrow palisade fringe on apical margin of tergite VII. Sternite VIII with broad anterior lobe associated with defensive gland reservoir and bearing numerous gland openings posteriorly.

Male. First four protarsomeres distinctly widened. Aedeagus ( Figs. 14–17 ) suboval, median lobe with truncated apex; parameres slightly or distinctly exceeding apex of median lobe; internal sac simple, narrow and long. Apical abdominal (genital) segment as in Fig. 12 .

Female. First four protarsomeres narrow. Genital segment ( Fig 13 ) with very narrow sternite IX, narrow and short gonocoxites, and significantly elongate styli, each with a very long apical seta.

Species included: Anthobiomorphus makranczyi sp.n., A. rougemonti sp.n.

Discussion. Based on the general shape of the body and the aedeagus, the presence of the postocular ridge (except Caucanthobium), the shape and structure of the pronotum with deep lateral pits and explanate lateral portions, Anthobiomorphus gen.n. undoubtedly belongs to the Anthobium group of genera ( Shavrin & Smetana 2017; etc.). This group contains several genera distibuted in the Holarctic Region: Acidota Stephens, 1829 , Anthobioides Campbell, 1987 , Anthobium , Arpedium Erichson 1839 , Camioleum Lewis, 1893 , Caucanthobium, Deinopteroloma Jansson, 1947 , Deliphrosoma Reitter, 1909 , Deliphrum Erichson, 1839 , and Olophrum Erichson, 1839 . In the shape of the body, pubescence and punctation of the forebody, the presence of distinct grooves in front of the ocelli and distinct notch in the anterior portion of the head between antennal insertion and anterior margin of eye, the shape of the gular sutures and moderately short elytra, within this group Anthobiomorphus gen.n. is most similar to the Holarctic genus Anthobium and the Caucasian Caucanthobium. Based on the moderately convex body, elongate apical palpomere of the maxillary palp, the structure of the pronotum with wide semicurcular impression and crenulate lateral margins, and punctation of the elytra, it somewhat recalls some species of the gracilipalpe and nigrum groups of Anthobium , distributed in China and the Himalayan Region ( Shavrin & Smetana 2017). Anthobium and Caucanthobium differ from Anthobiomorphus gen.n. by the shape of the the glossa and galea; the shape of the conical and elongate preapical maxillary palpomere, widened apicad; the markedly less protruding eyes; the shape of the laterobasal margin of the pronotum, usually gradually narrowed toward the hind angles; and markedly shorter styli of the gonocoxites. Additionally, the monotypic Caucanthobium differs from the new genus by the larger and paler body; reduced postocular ridge; the presence of the median carina on the mesoventrite; the strongly dilated male protarsi; the morphology of the strongly asymmetric aedeagus; and the markedly wider and shorter gonocoxites.

Anthobiomorphus gen.n. can be distinguished from all genera listed above by the following combination of morphological features: 1) apical margin of glossa with irregularly dissected narrow parts, each rounded apically ( Fig. 5 ); 2) preapical maxillary palpomere short, about as long as wide ( Figs. 6–7 ); 3) galea broadly divided into two parts ( Figs. 6–7 ); 4) strongly protruding eyes; 5) laterobasal margin of the pronotum with very sharp, straight and moderately long emargination; 6) female genital segment with short, narrow gonocoxites and significantly elongate styli and stylar setae ( Fig. 13 ).

Etymology. The generic name is a combination of the existing name Anthobium and the ending “- morphus ” (-shaped). It alludes to the similarity of the new genus to Anthobium .

Key to species of Anthobiomorphus

1 Pronotum convex in medioapical portion, lateral edges from middle indistinctly narrowed anteriad towards markedly protruding anterior angles. Forebody dark-brown to black. Aedeagus relatively narrow, parameres slightly exceeding apex of median lobe ( Fig. 14 ). Body larger: 3.35–4.00 mm. Habitus as in Fig. 1 . China (Yunnan).................... A. rougemonti sp.n.

- Pronotum convex in middle, lateral edges from middle distinctly narrowed anteriad towards slightly protruding apical angles. Forebody reddish-brown. Aedeagus wide, parameres markedly exceeding apex of median lobe ( Fig. 16 ). Body smaller: 3.25– 3.35 mm. Habitus as in Fig. 2 . India (West Bengal), Nepal...................................... A. makranczyi sp.n.

Figures

FIGURES 1–2. Habitus of species of Anthobiomorphus: 1–A. rougemonti (paratype, Lijiang), 2–A. makranczyi (holotype). Scale bars: 1.0 mm.

FIGURES 3–7. Mouthparts of Anthobiomorphus (3–6–A. rougemonti, 7–A. makranczyi): 3–labrum (dorsal view), 4–mandibles (left and right; dorsal view), 5–labium and mentum (ventral view), 6–maxilla (left; ventral view), 7–maxillary palpus and galea of left maxilla (dorsal view). Scale bars: 0.1 mm.

FIGURES 14–17. Aedeagi of Anthobiomorphus rougemonti (14–15: holotype) and A. makranczyi (16–17: holotype): 14, 16– parameral view, 15, 17–lateral view. Scale bars: 0.1 mm.

FIGURES 8–13. Abdominal segments of Anthobiomorphus rougemonti: 8–male tergite VIII (dorsal view), 9–male sternite VIII (ventral view), 10–female tergite VIII (dorsal view), 11–female sternite VIII (ventral view), 12–male genital segment (IX–X, dorsal view), 13–female genital segment (IX–X, dorsal view). Scale bars: 0.1 mm.