Brachysomus (Brachysomus) dubius Yunakov, 2006

Yunakov, Nikolai, 2022, A review of the genus Brachysomus Schoenherr (Coleoptera: Curculionidae: Entiminae), Zootaxa 5193 (1), pp. 1-165 : 41

Brachysomus (Brachysomus) dubius Yunakov, 2006

Fig. 196 , 236B

Brachysomus dubius Yunakov, 2006: 297 . Type locality: Bosnia and Herzegovina, Domanovice.

Redescription. Measurements: Body length 2.3 mm, width 1.25 mm. Vestiture: Body densely covered with gray, elongate, shallowly excised apically, recumbent scales and longer, evenly widened, blunted apically, erect setae; setae as long as width of interstriae.Antennae and ventrites light brown with fine light pubescence; legs light brown with setae evenly widened apically. Colouration: Body, legs and antennae brown.

Head: Rostrum as long as wide, weakly narrowed apically. Antennal sockets distinctly visible in dorsal view. Pterygia not projecting from outline of rostrum. Antennal scrobes sharply developed and deep, with divergent margins, reaching the ventral side of rostrum. Epistome without carina. Epifrons narrowed to midlength, parallelsided from midlength to apex, weakly longitudinally convex, without carina, with deep median longitudinal sulcus, separated from vertex by weak but clearly visible transverse depression. Vertex weakly convex, finely punctate. Eyes oval (VW/ELD = 1.7), weakly convex, highest at middle. Antennae: Scape gently curved, strongly widened along distal 1/3; funicular antennomeres: 1st and 2nd elongate (L/W = 2–2.3), 3rd–6th moniliform; 7th transverse; club egg-shaped or oblong-egg-shaped.

Thorax: Pronotum transverse (PL/PW = 0.79), widest posteriad of mid length, strongly evenly convex at disc and sides, constricted anteriorly and posteriorly, densely, shallowly punctate, disc with well-developed lateral depressions. Elytra: oval (EL/EW =1.26), strongly convex at disc. Interstriae of elytra flat, glabrous, 2x wider than striae, Punctures, narrowly separated. Spaces between punctures, very weakly concave, somewhat narrower than diameter of puncture. Legs: Fore tibiae straight, with apical external angle not protruding. Hind tibiae with small mucro, 2nd tarsomere as long as wide, 5th fore tarsomere extending beyond apical lobes of 3rd by 0.60 length of the lobes.

Abdomen: First ventrite with posterior margin weakly sinuate, 5th ventrite weakly evenly convex, truncate, with scattered pale hairs. Male genitalia: Aedeagus heavily sclerotized through entire length, 0.83x as long as apodemes, evenly narrowed apically, apex narrowly rounded, ventral membranes triangular, slightly sclerotized. Parameres vestigial, posterior margin of basal piece straight. Female unknown.

Diagnosis. Brachysomus dubius is very similar to B. hirtus , differing in shape and larger size of the aedeagus and denser body vestiture, 5th ventrite evenly convex, not flattened on apical third (which is so for B. hirtus ). Eyes are weakly convex, rostrum weakly narrowing apically, but not parallel-sided in contrast to B. hirtus and B. fasciatus .

Distribution. Bosnia and Herzegovina (Domanovice).

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

Type material. BOSNIA AND HERZEGOVINA: Holotype, ♂ (NHMUK): ‘Herzegowina, Domanovich, Reitter 79’ (printed); ‘ Brachysomus hispidus Redt. ’ (handwritten); ‘G. C. Champion C., B. M. 1927–409’ (printed).

Figures

FIGURE 196. Brachysomus dubius: A: aedeagus, dorsal view; B: tegmen; C: head of male; D: antenna; E: fore tibia of male; F: hind tibia of male; G: scales 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.