Brachysomus (Hippomias) merkli Yunakov, 2006

Yunakov, Nikolai, 2022, A review of the genus Brachysomus Schoenherr (Coleoptera: Curculionidae: Entiminae), Zootaxa 5193 (1), pp. 1-165 : 69

Brachysomus (Hippomias) merkli Yunakov, 2006

Fig. 161 , 224 , 240A

Brachysomus merkli Yunakov, 2006: 310 . Type locality: ‘Hungaria meridionale’

Brachysomus machaerophorus Białooki, 2007: 156 , syn. n. Type locality: Romania, Tulcea

Redescription. Measurements: Body length 1.82–2.20 mm, width 1.00–1.25 mm, (in holotype 2.20 and 1.25 mm). Vestiture: Body evenly covered with light, fine, small, narrow, lanceolate scales and long, narrow, acute, erect setae; setae as long as interstrial width. Colouration: Body brown, antennae and legs yellow-brown.

Head: Rostrum noticeably narrowing to level of antennal insertion, as long as wide. Pterygia clearly visible in dorsal view, weakly projecting from outline of rostrum. Epifrons, widened to middle, then parallel-sided to antennal insertion, not separated from vertex by transverse depression, with shallow median longitudinal sulcus, rather developed in female, not developed or vestigial in male. Eyes small (VW/ELD = 2.50), strongly convex, situated lower of level of vertex. Vertex weakly convex. Antennae: scape weakly and evenly curved, widened distally, 2x wider at apex than at base; funicular antennomeres: 1st and 2nd elongate, 1st (L/W = 1.5) thicker than 2nd (L/W = 1.3); 3rd–7th as long as wide; club broad-spindle-shaped, weakly separated from funicle.

Thorax: Pronotum transverse (PL/PW = 0.70–0.78), evenly convex at sides, widest at middle. Disc evenly and weakly convex longitudinally, finely, densely punctate, and granulate at sides. Elytra: oval, in female broadoval, evenly convex at disc and sides. Punctures shallow, slightly separated; spaces between punctures somewhat narrower than diameter of puncture, situated deeper than interstrial level. Interstriae slightly convex, shiny, 2x wider than striae. Legs: Femora moderately swollen in middle part. Fore tibiae: external margin straight, external apical angle weakly projecting from contour. First tarsomere triangular, 2nd strongly transverse. Fifth fore tarsomere extending beyond apical lobes of 3rd by 0.75 length of the lobes.

Abdomen: Fifth ventrite rounded at apex. Male genitalia: Median lobe 1.7x shorter than apodemes, weakly sclerotized, parallel sided, strongly narrowed apically, narrowly rounded at apex. Spermatheca: ramus as long as collum; corpus slightly swollen.

Diagnosis. Brachysomus merkli is closely related to B. polonicus , clearly differing in the structure of the genitalia in both sexes and characters of the pubescence of the body: setae along the interstriae narrower, longer, acute apically, as long as width of interstriae; body evenly and finely covered with narrow, piliform, and lanceolate grey scales. Fourth to 7th funicular antennomeres as long as wide, in B. polonicus noticeably transverse. Tarsi thin and long. First ventrite strongly sinuate at the posterior margin, in B. polonicus not sinuate.

Distribution. This species is so far known only from SE Romania.

Remarks. Examination of two female paratypes of the recently described B. machaerophorus reveals it is conspecific with B. merkli in the structure of the spermatheca.

Type material. Holotype, ♀ (HNHM), ‘Hung[aria] mer[idionale], Merkl’ (handwritten). Paratypes, 2♀ (HNHM, ZIN), as holotype.

Additional material examined. ROMANIA: 1♂ (UWCP), Somova env., W Tulcea 13.vi.2005 P. Białooki/ Holotype, Brachysomus machaerophorus Białooki ; 1♀ (MMc), idem, P. Białooki/ Paratype, Brachysomus machaerophorus Białooki ; 1♀ (MMc), idem, 19.v.2006, P. Białooki/ Paratype, Brachysomus machaerophorus Białooki ; 1♀ (MMc), idem, 20.v.2006, P. Białooki/ Paratype, Brachysomus machaerophorus Białooki.

Figures

FIGURE 224. Brachysomus merkli: A: aedeagus; B: tegmen; C: spermatheca; D: antenna; E: scales of elytra.

FIGURE 240. Occurrence map of Brachysomus subgenus Hippomias.

FIGURES 156–163. Brachysomus and Nanomias, details: 156, 157: Scaling of anterior margin of pronotum, indicated by arrow: 156: B. mikati. 157: B. albanicus. 158: Nanomias skodai. 159: idem, head dorsal view. 160: idem, head lateral view. 161: B. merkli, male. 162: idem, head dorsal view. 163: idem, head lateral view.