Anthobium gracilipalpe ( Champion, 1920 )

Shavrin, Alexey V. & Smetana, Aleš, 2017, A revision of Eastern Palaearctic Anthobium Leach, 1819 (Coleoptera: Staphylinidae: Omaliinae: Anthophagini). I. Gracilipalpe, morchella and nigrum groups, Zootaxa 4365 (1), pp. 1-39 : 4-9

3.1.2.1. Anthobium gracilipalpe ( Champion, 1920)

( Figs. 1 , 4, 7, 10, 13 , 16, 19, 22, 25 , 28 , 31–32 , 38 )

Eudeliphrum gracilipalpe Champion, 1920: 244

Lathrimaeum gracilipalpe: Cameron, 1930: 153 ; Scheerpeltz, 1933: 1056

Lathrimaeum (Lathrimaeum) gracilipalpe: Scheerpeltz, 1961: 75

Anthobium gracilipalpe: Herman, 2001b: 233

Anthobium (Anthobium) gracilipalpe: Smetana, 2004: 238 ; Schülke & Smetana 2015: 306

Type material examined: Lectotype (here designated) of Eudeliphrum gracilipalpe Champion, 1920 ♂ [specimen was reglued on a new plate, old plate under a new; abdominal tergite VIII, sternite VIII and apical abdominal segment are glued on the same plate under a beetle; microvial with the preparation of the aedeagus in glycerine was pinned under an old plate]: ‘SYN- | TYPE’ <round label with blue margin, printed>, ‘ Type | H. T.’ <round label with red margin, printed>, ‘ ♂ ’ <rectangular label, printed>, ‘W. Almora, | Kumaon, | India. H.G.C.’ <rectangular label, printed>, ‘ Eudeliphrum | gracilipalpe | Champ.’ <rectangular label, handwritten in black Indian ink>, ‘ Eudeliphrum | gracilipalpe, Champ. | G.C. Champion det.’ <rectangular label, printed>, ‘H.G. Champion. | 1920 – 69’ <rectangular label, printed>, ‘ LECTOTYPE | Eudeliphrum | gracilipalpe Champion, 1920 | Shavrin A.V. des. 2016’ <red rectangular label, printed>, ‘ Anthobium | gracilipalpe Champion, 1920 | Shavrin A.V. det. 2016’ <rectangular label, printed> ( BMNH).

Paralectotypes of Eudeliphrum gracilipalpe Champion, 1920: 2 ♂♂ [specimens with small second rectangular label: ‘♂’], 2 ♀♀ [one specimen was dissected: plastic plate with abdominal tergite VIII, sternite VIII and genital segment in Canadian balsam was pinned under the plate with beetle; both specimens with small second rectangular label: ‘♀’]: ‘SYN- | TYPE’ <round label with blue frame>, ‘W. Almora, | Kumaon. | India. H.G.C.’ <rectangular label, printed>, ‘ Eudeliphrum | gracilipalpe, Champ | G.C.Champion det.’ <rectangular label, printed>, ‘PARALECTOTYPE | Eudeliphrum | gracilipalpe Champion, 1920 | Shavrin A.V. des. 2016’ <red rectangular label, printed>, ‘ Anthobium | gracilipalpe Champion, 1920 | Shavrin A.V. det. 2016’ <rectangular label, printed> (BMNH).

Additional material. INDIA: UTTARANCHAL: 1 ♂: ‘Kumaon U.P. | Oct. 1918. HGC. W. Almora Divn’, ‘2464’, ‘ Eudeliphrum gracilipalpe’ (BMNH); 1 ♀: ‘♀’, ‘2837’, ‘U. Gumti Val. W. Almora Dn. Apr.`19. HGC’ (BMNH); 1 ♀: ‘Garhwal (UP), 4 km au sud de Bhatwari. 1400 m a.s.l. 23.10.1979. I. Löbl’ (MHNG); NEPAL: 1 ♀: ‘E. NEPAL: KOSI Val. Induwa Kola 2850 m, 15.IV. [19]84. [I.] Löbl—[A.] Smetana’ <? Deinopteroloma det. M.K. Thayer 1989> <probably Anthobium M.K. Thayer det. 2013> (MHNG).

Redescription. Measurements (n=9): HW: 0.80–0.95; HL: 0.46–0.55; AL (lectotype): 1.99; OL: 0.24–0.25; PL: 0.71–0.75; PW: 1.35–1.39; ESL: 1.72–2.00; EW: 1.76–1.90; AW: 1.55–1.64; MTbL (lectotype): 1.10; MTrL (lectotype): 0.50 (MTrL 1–4: 0.30; MTrL 5: 0.20); AedL: 0.65; TL: 4.00–4.50(lectotype).

Body elongate, convex. Brown to dark brown, sometimes head black; antennomeres 4–11, apical segments of abdomen yellow-brown; antennomeres 1–3, mouthparts and legs reddish-brown. Body shiny, without microsculpture except of posterio-lateral portions of head and neck with coarsely rugose and abdominal tergites with distinct isodiametric microsculpture. Frons and middle portion of head with sparse, moderately small irregular punctation, denser on bottom of transverse median impression, punctation of posterior part of infraorbital ridges distinctly larger, denser and deeper; middle part of neck with regular, large and deep punctation; pronotum with coarse and dense punctation on middle elevation, distinctly sparser on medio-basal third between impressions, with finer smaller punctation on lateral portions; scutellum without visible punctures; punctation of elytra as that on pronotum, distinctly denser and deeper on prescutellar area, each elytron with eight vague and tangled longitudinal rows of serial punctures, punctures of four medial rows located very close together, adjacent four rows separated by impunctated longitudinal elevation, remaining elytral punctures forming indistinct and tangled diagonal rows and becoming irregularly scattered laterally; abdominal tergites with very sparse, indistinct small punctures. Body glabrous; clypeus with several long tactile setae; anterior part of frons with several irregular small setae; middle part of pronotum and surface of each elytron with irregular and very sparse erect setae; abdominal tergites with more or less regular, sparse and extremely short setation. Habitus as in Fig. 1 .

Head 1.7 times as wide as long; anterior portion of frons with obliquely elevated supra-antennal prominences; vertex irregularly elevated, with middle transverse triangular impression between posterior third of eyes and with deep occipital furrow between ocelli, with elongated, moderately wide and deep grooves in front of ocelli, reaching posterior third of eye; head somewhat abruptly narrowed toward neck behind obtuse postocular ridges; distance between postocular ridge and posterior margin of eye as long as two nearest facets; anterior portion between antennal insertion and anterior margin of eye with wide semicircular notch. Eyes large and convex. Ocelli large, equal to diameter of two-three nearest punctures, very convex, situated on level of postocular ridge; distance between ocelli about as long as distance between ocellus and posterior margin of eye. Labrum moderately narrow, with widely rounded latero-apical portions, with deep apical emargination ( Fig. 4 ). Mandibles short, with wide basal portion, with moderately large preapical tooth on right mandibula ( Fig. 7 ). Labium wide, with elongated submentum ( Fig. 13 ). Apical segment of maxillary palp more than twice as long as preceeding segment ( Fig. 10 ). Gular sutures with widely rounded apical parts, narrowly diverging posteriad; shortest distance between sutures located at level of middle length of eye. Antenna with elongated antennomeres, reaching one-fourth of elytral length when reclined; antennomere 3 distinctly longer than antennomeres 2 and 4; measurements of antennomeres (lectotype): 1: 0.20 × 0.10; 2: 0.15 × 0.05; 3: 0.19 × 0.05; 4–5: 0.17 × 0.07; 6–8: 0.19 × 0.07; 9: 0.18 × 0.07; 10: 0.16 × 0.10; 11: 0.20 × 0.10.

Pronotum 1.8–1.9 times as wide as long, 1.4–1.6 times as wide as head, widest slightly above middle, markedly more narrowed posteriad than anteriad; apical margin as wide as posterior margin, sinuately emarginated; anterior angles widely rounded, indistinctly protruded anteriad; posterior angles obtuse; latero-apical and lateral edges of pronotum with regular smooth crenulation; pronotum with wide middle elevation, with very deep longitudinal impression in apical part, and with a pair of deep to very deep semioval impressions in medio-basal third; lateral portions slightly explanate, each with very deep pit at middle. Prothorax with elongated intercoxal process and wide protruded mesosternal processes. Mesothorax transverse, with distinctly convex middle part and acute intercoxal process not reaching posterior margin of mesocoxae. Visible part of scutellum small, triangular. Metathorax wide and convex, with deep intercoxal cavities and rounded apex of intercoxal process.

Elytra indistinctly widened apicad, reaching apical margin of abdominal tergite IV or V, slightly longer than wide, about two and half times as long as pronotum, with rounded shoulders and widely rounded apical margins truncated at suture; lateral portions of elytra very narrow, not explanated, latero-apical margins with small crenulation, more flattened in middle and reduced in apical third; each elytron with three indistinct to distinct median longitudinal elevations beginning from basal portion and almost reaching apical part of elytra, basal part of first longitudinal elevation more convex. Wings fully developed.

Legs moderately long and slender; tibia covered by elongated setae, stronger on lateral margin, with a few strong setae on lateral margin near apex; first four protarsomeres of both sexes dilated; metatarsus more than twice as long as metatibia.

Abdomen distinctly narrower than elytra, with a pair of moderately large oval tomentose spots in middle of tergite V; intersegmental membranes between tergites IV–VII narrow to wide, covered by brickwall-like sculpture.

Male. Ventral surface of front tibia with moderately large triangular dilatation about middle, with distinctly concaved margin in front of it, with row of nine bulbose setae almost reaching apex. Apical margin of abdominal tergite VIII ( Fig. 16 ) and sternite VIII ( Fig. 19 ) slightly sinuate. Aedeagus ( Fig. 31 ) with widely rounded apex of median lobe; parameres slightly exceeding apex of median lobe, slightly asymmetrical, with slightly longer left paramere, with three very short apical and additional two or three preapical setae; internal sac long with fields of sclerites consisting of numerous thorns. Aedeagus laterally as in Fig. 32 .

Female. Front tibia simple, without modification. Apical margin of abdominal tergite VIII ( Fig. 22 ) slightly sinuate. Apical margin of abdominal sternite VIII ( Fig. 25 ) rounded. Genital segment ( Fig. 28 ) with elongated sternite IX, gonocoxites slightly widened basally, styli elongated and narrow.

Comparative notes. Based on the anterior angles of the pronotum slightly protruded anteriad and asymmetrical apical portions of parameres, A. gracilipalpe is similar to the Chinese A. daliense sp.n., from which it differs by larger and denser punctation of head and pronotum, by the presence of very deep longitudinal and a pair of semioval impressions on medio-basal third of the pronotum, as well as by the slightly wider apex of median lobe of the aedeagus, shorter apical parts of parameres and different structure of the internal sac.

Distribution. The species is known from Uttaranchal Province of India and eastern Nepal ( Fig. 38 ).

Bionomics. Specimens were collected at elevations from 1400 to 2850 m a.s.l. The detailed ecological data are unknown.

Remarks. The species was described by Champion (1920) based on three males and two females from “W. Almora in Kumaon”. The elongated antennae and maxillary palpomeres, structure of the forebody, mouthparts and legs were the reasons for Champion to erect for it the monotypic genus Eudeliphrum , which he compared to Deliphrum Erichson, 1839 and Phyllodrepoidea Ganglbauer, 1895 , and by the elongated third antennomere with Lesteva Latreille, 1797 and Geodromicus Redtenbacher, 1857 . All these characters are variable within Anthobium , sometimes significantly. The apical maxillary palpomere is variable in length and shape in many species: it can be twice as long as preceeding segment or slightly shorter, significantly narrowing apicad or longer, slightly widened in middle and gradually narrowing toward more or less widely rounded apex. The triangular dilatation of the front tibia in male, noticed by Champion, occurs not only in some species of Anthobium , but in related genera, e.g., Arpedium Erichson, 1839 , Deinopteroloma , Olophrum Erichson, 1839 . Eudeliphrum was subsequently synonymized by Cameron (1930) with Lathrimaeum .

Anthobium gracilipalpe is here recorded for the first time from Nepal.

Figures

FIGURE 38. Distribution of Anthobium gracilipalpe group: A. gracilipalpe (black circles), A. daliense (black triangle), A. nivale (black square).

FIGURES1–3. Habitusof Anthobium gracilipalpe group:1—A.gracilipalpe (INDIA:Garhwal),2—A.nivale (holotype), 3— A. daliense (holotype). Scale bars:1.0 mm.

FIGURES 4–15. Mouthparts (dorsal view) of Anthobium (4, 7, 10, 13—A. gracilipalpe, 5, 8, 11, 14—A. morchella, 6, 9, 12, 15—A. nigrum): 4–6—labrum, 7–9—mandibles (left and right), 10–12—maxilla (right), 13–15—labium and submentum. Scale bars:0.1 mm.

FIGURES 16–27. Abdominal segments of Anthobium (16, 19, 22, 25—A. gracilipalpe, 17, 20, 23, 26—A. morchella, 18, 21, 24, 27—A. nigrum): 16–18—male tergite VIII (dorsal view), 19–21—male sternite VIII (ventral view), 22–24—female tergite VIII (dorsal view), 25–27—female sternite VIII (ventral view).Scale bars: 0.1 mm.

FIGURES 28–30. Female genital segment (dorsal view) of Anthobium: 28—A. gracilipalpe, 29—A. morchella, 30—A. nigrum. Scale bars:0.1 mm.

FIGURES31–34.Aedeagus of Anthobium gracilipalpe (31–32: paratype)and A. nivale (33–34:holotype):31, 33—parameral view, 32, 34—lateral view.Scale bars: 0.1 mm.