Brachysomus (Brachysomus) dispar Penecke, 1910

Yunakov, Nikolai, 2022, A review of the genus Brachysomus Schoenherr (Coleoptera: Curculionidae: Entiminae), Zootaxa 5193 (1), pp. 1-165 : 31-32

Brachysomus (Brachysomus) dispar Penecke, 1910

Figs. 77, 78 , 187 , 235B

Brachysomus dispar Penecke, 1910: 245 . Type locality: Chernowitz [= Chernivtsi, Ukraine]; Dalla Torre et al., 1937: 172; Košťál, 1991a: 104.

Redescription. Measurements: Body length 2.05–2.50 mm, width 1.15–1.50 mm. Vestiture: Body sparsely covered

with small, slender scales and elongate, spatulate setae (as long as width of scales). Ventral side pilose. 5th ventrite in males with two bilateral bunches of pale hairs on posterior margin. Colouration: Scales pale-grey. Integument of body reddish-brown, appendages slightly paler.

Head: Rostrum weakly transverse or as long as wide [RL/RW = 0.94–1.00 (0.96)], narrowed from base to middle, lateral marginss in line with lateral margins of temples. Antennal sockets distinctly visible in dorsal view. Pterygia distinctly projecting from contour of rostrum.Antennal scrobes sharply developed, deep, directed to ventral margin of eye, reaching ventral side of rostrum. Epistome flat, weakly delimited by thin U-shaped carina. Epifrons parallel-sided, flat, not carinate, median longitudinal sulcus absent or weakly developed, separated from vertex by weak but clearly visible transverse depression. Vertex flat. Eyes oval, weakly convex [VW/ELD = 2.0–2.06], highest at middle. Antennae: Scape gently curved, evenly widened to apex; funicular antennomeres: 1st [L/W in males 1.6; in females 2], 2nd [L/W in males 1.25; in females 2]; 3rd–7th transverse: 3rd [L/W in males 0.75; in females 1]; 4 th –5th [L/W = 0.75]; 6th [L/W = 0.6–0.75]; 7th [L/W = 0.5–0.6]. Club egg-shaped.

Thorax: Pronotum weakly transverse [PL/PW = 0.70–0.73 (0.72)], gently and evenly convex at disc and sides, evenly constricted anteriorly and posteriorly, densely and shallowly punctate. Elytra: in female oval, and strongly convex at disc, in male oblong-oval and weakly convex at disc. Elytral interstiae weakly convex, 2.0–2.5x wider than striae. Punctures broadly separated; spaces between punctures very weakly concave, somewhat narrower than diameter of puncture. Legs: Fore tibiae straight, with apical external angle not protruding. Second tarsomere triangular. Fifth fore tarsomere extending beyond apical lobes of 3rd by length of the lobes.

Abdomen: First ventrite with posterior margin weakly sinuate. Male 5th ventrite with distinct depression, apical margin truncate, with biklateral bunches of pale hairs. Female 5th ventrite flat, with apical margin widely rounded. Male genitalia: Aedeagus heavily sclerotized through entire length; median lobe, as long as apodemes, weakly narrowed apically; apex truncate and dentate on dorsal surface ( Fig. 187A ). Ventral membranes triangular, membranous.Parameres 0.5x as long as width of tegmenal ring; posterior margin of basal piece sinuate. Spermatheca: Ramus and collum connate at base, both basally constricted; ramus as long as collum.

Diagnosis. Brachysomus dispar is very similar to B. subnudus , differing by following characters: midle and hind tibiae without mucro; apex of median lobe truncate and dentate; epifrons flat, without median longitudinal sulcus, evenly narrowed apically; interstriae with elongate, spatulate, scale-like setae; male 5th ventrite with distinct depression and groups of hairs; tibiae in both sexes without mucro; fore tibiae in male internally weakly emarginate.

Distribution. Romania, Slovakia, Ukraine (Zakarpatska, Chernivtsi and Khmelnytskyi Provinces).

Bionomics. As for B. subnudus . The species is recorded from 120 to 900 m a.s.l. ( Benedikt 2001).

Remarks. One male from NMPC labeled as “Typus” was not used in the original description and is not a type specimen ( Košťál 1991a).

Type material. Lectotype, ♂, (designation: Košťál, 1991a) (MTD) “Bukovina, Czernowitz” (printed), “ Btrachysomus dispar m., Penecke det.” “Typus” (red, printed); “ Btrachysomus dispar Penecke, Košťál design, 1987”. Paralectotypes 2♂, 4♀ (MTD) with label as in lectotype.

Additional material examined. ROMANIA: 1♂, 1♀, ‘Transsylvania’ (MTD). SLOVAKIA: 1♂, ‘Slovakia occ., 29.5.1996, Uhtov, Podhradie env., v. Rokoš, 700–1000 m, S. Benedikt leg.’ (BRc); 1♀, ‘Slovakia occ., 30.5.1996, Lutov env., v. Bradlo, S. Benedikt leg.’ (BRc). UKRAINE: 1♂, Khmelnytskyi Prov., Kamianets- Podilskyi, 30.iv.1901 V. Jakubowski & I. Jakubowski leg. (ZIN); 1♂, 1♀, idem, 24.iv.1911 V. Jakubowski & I. Jakubowski leg. (ZIN); 6♂, 6♀, ‘Bukovina, Czernowitz [= Chernivtsi]’ (NMPC, MTD).

Figures

FIGURE 187. Brachysomus dispar: A: aedeagus, dorsal and lateral view; B: tegmen; C: spermatheca; D: sternite VII; E: tergite VIII.

FIGURE 235. Occurrence map of Brachysomus: A: B. echinatus; B: Brachysomus s. str.

FIGURES 71–78. Brachysomus, details: 71, 72: B. styriacus. 73, 74: B. frivaldszkyi. 75, 76: B. subnudus. 77, 78: B. dispar.