Brachysomus (Brachysomus) mucronatus Yunakov, 2006

Yunakov, Nikolai, 2022, A review of the genus Brachysomus Schoenherr (Coleoptera: Curculionidae: Entiminae), Zootaxa 5193 (1), pp. 1-165 : 42

Brachysomus (Brachysomus) mucronatus Yunakov, 2006

Fig. 197 , 236B

Brachysomus mucronatus Yunakov, 2006: 297 . Type locality: Montenegro, Dobrota.

Redescription. Measurements: Body length 2.30–2.60 mm, width 1.10–1.40 mm, in holotype 2.30 mm and 1.10 mm, respectively. Colouration: Body brown, legs and antennae lighter. Vestiture: Body densely covered with weakly metallic, elongate, shallowly excised apically, recumbent scales and longer, evenly widened, blunted apically, strongly erect setae. Scales in males noticeably excised apically, obtuse in females. Setae as long as width of interstriae. Antennae and ventrites light brown with fine light pubescence, legs light brown, with setae evenly widened apically.

Head: Rostrum as long as wide, narrowed from base to midlength, parallel-sided from midlength to apex. Antennal sockets distinctly visible in dorsal view. Pterygia projecting from outline of rostrum. Antennal scrobes sharply developed and deep, with divergent margins, reaching ventral side of rostrum. Epistome flat, without carina. Epifrons narrowed to midlength, parallel-sided from midlength to apex, weakly longitudinally convex, without carina, with deep median longitudinal sulcus, separated from vertex by weak but well visible transverse depression. Vertex weakly convex, finely punctate. Eyes oval (VW/ELD = 2.5–3.0), strongly convex, highest at middle.

Antennae: Scape gently curved along basal 1/3, sharply widened along distal 1/3; funicular antennomeres: 1st and 2nd elongate (L/W = 2.0–2.3); 3rd–6th moniliform; 7th transverse; club egg-shaped or oblong-egg-shaped.

Thorax: Pronotum transverse [PL/PW = 0.73–0.85 (0.79)], strongly and evenly convex at disc and sides, constricted anteriorly and posteriorly, densely, coarsely, and shallowly punctate, disc with well developed lateral depressions. Elytra: oval to broadly-oval (EL/EW in males = 1.30–1.43, in females = 1.25–1.34). Disc strongly convex longitudinally and weakly convex transversaly. Interstriae of elytra flat, 2x wider than striae. Punctures slightly separated. Spaces between punctures very weakly concave, somewhat narrower than diameter of a puncture.

Legs: Fore tibiae straight, with apical external angle not protruding. Hind tibiae in male with strong, long, thornshaped mucro. Second tarsomere weakly transverse (L/W = 0.50). Fifth fore tarsomere extending beyond apical lobes of 3rd by 0.60 length of the lobes.

Abdomen: First ventrite with posterior margin weakly sinuate. Male 5th ventrite flat, apically truncate. Male genitalia: Aedeagus heavily sclerotized through entire length, median lobe as long as apodemes, evenly narrowed apically, apex attenuate. Ventral membranes triangular. Parameres vestigial, posterior margin of basal piece straight.

Spermatheca: ramus and collum slightly divided at base, ramus with serrate margin, 2x as long as collum.

Diagnosis. Brachysomus mucronatus is very similar to B. fasciatus , differing in the strong, long, thorn-shaped mucro on the male metatibiae, rostrum narrowing apically, less convex eyes, and in the structure and shape of genitalia in both sexes. From B. hirtus , in addition to the above listed characters, it differs by the rather strongly curved antennal scape, small, strongly convex eyes (in B. mucronatus VW /ELD = 2.5–3.0, in B. hirtus VW /ELD = 2).

Distribution. Montenegro (coast of Boka Kotorska Bay).

Bionomics. Unknown, probably as in other species of the B. hirtus group.

Type material. MONTENEGRO: Holotype,♂ (NMPC): ‘Dobrota, Juni 1916’ (printed), ‘Collectio Dr. Jureček, H. Jurečková (printed)’. Paratypes: 3♀ (NMPC), some data as holotype; 1♀ (NMPC), ‘Cattaro (= Kotor), 10.7.1916’, ‘Collectio Dr Jureček, H. Jurečková’; 1♂, 3♀ (NMPC, ZIN), ‘Boc.[ca] di Cattaro (= Boka Kotorska Strait), April, 1916’; 3♀ (NMPC),’Boc.[ca] di Cattaro, Rittm. Matcha’, ‘Collectio Dr Jureček, H. Jurečková’; 1♂, 1♀ (NMPC), ‘Cattaro, Dal.[matia], 1916’, ‘ Brachysomus hirtus Boh. ’

Figures

FIGURE 197. Brachysomus mucronatus: A: aedeagus, dorsal view; B: tegmen; C: spermatheca; D: head of male; E: head of female; F: antenna G: fore tibia of male; H: hind tibia of male; I: setae of elytra.

FIGURE 236. Occurrence map of Brachysomus: A: B. hirtus; B: Brachysomus hirtus species group. Red triangles indicate occurrence of males of B. hirtus.