Brachysomus (Brachysomus) strawinskii Cmoluch, 1960

Yunakov, Nikolai, 2022, A review of the genus Brachysomus Schoenherr (Coleoptera: Curculionidae: Entiminae), Zootaxa 5193 (1), pp. 1-165 : 25-26

Brachysomus (Brachysomus) strawinskii Cmoluch, 1960

Figs. 39, 40 , 91, 92 , 182 , 235B

Brachysomus strawinskii Cmoluch, 1960: 111 . Type locality: environs of Lublin, near Bug River; Cmoluch 1962: 42; Smreczyński 1966: 86; Gosic & Łętowski 2003: 256; Białooki 2007: 164 (subgenus Hippomias ).

Redescription. Measurements: Body length 2.05–2.80 mm, width 1.35–1.75 mm. Vestiture: Body densely covered with small, round scales and very short, weakly visible, almost recumbent, oval, scale-like setae. Scales denser along sides of pronotum and interstriae. Disc of pronotum with sparse vestiture, median squamose line not developed. Setal rows confused. Setae as long as 0.20–0.25 width of interstriae. Antennae, legs, and abdomen covered with pale, piliform, and lanceolate scales, and apically widened, obtuse setae. Colouration: Integument of body darkbrown to black, appendages distinctly paler. Scales and erect setae pale grey, without pearly shine; spotted pattern not developed.

Head: Rostrum weakly transverse [RL/RWA 0,86–0,93 (0,89)], parallel-sided; sharply separated from head capsule. Pterygia not projecting from outline of rostrum. Antennal slightly visible in dorsal view. Scrobes sharply developed, deep, directed to ventral margin of eye, and reaching ventral side of rostrum. Epistome flat, delimited from epifrons by U-shaped thin carina. Epifrons parallel-sided, weakly longitudinally convex, with thin interrupted carina and weak median longitudinal sulcus, separated from vertex by weak but clearly visible transverse depression. Vertex weakly convex, finely longitudinally punctate. Eyes oval, weakly convex (FW/ELD = 2), highest at middle.

Antennae: Scape gently curved, strongly widened along distal 1/3; funicular antennomeres: 1st elongate, 2x longer than wide, 2nd 1.5x longer than wide; 3rd–7th transverse; club egg-shaped.

Thorax: Pronotum transverse [PL/PW = 0.63–0.65 (0.64)], widest at middle, gently and evenly convex at disc and sides, evenly constricted anteriorly and posteriorly, densely, shallowly punctate. Disc without lateral depressions.

Elytra: highly variable in shape, broadly-oval to globose, strongly convex at disc and sides [EL/EW= 1,28–1,29]. Elytral interstiae weakly convex, shiny, 2x wider than striae. Punctures dense, slightly separated; spaces between punctures concave, somewhat narrower than diameter of puncture. Mesonotum and base of elytra vertical. Scutellar shield slightly visible. Legs: Femora moderately swollen around midlength. Fore tibiae straight, with apical external angle not protruding. Hind tibiae in male without mucro. Second tarsomere weakly transverse. Fifth fore tarsomere extending beyond apical lobes of 3rd by 0.75 length of the lobes.

Abdomen: First ventrite with posterior margin straight. Male 5th ventrite with weak depression, apical margin obtuse, with bilateral bunches of pale hairs. Male genitalia: Aedeagus heavily sclerotized at apex, ventral wall membranous; median lobe narrowed apically, apex narrowly rounded, not dentate; endophallus evenly covered with microscopic spicules, endophallic sclerite bifurcate. Ventral membranes rounded, slightly sclerotized. Parameres free, as long as width of tegmenal ring; posterior margin of basal piece sinuate Spermatheca: ramus and collum slightly separated, equal in length.

Diagnosis. This species is very similar to B. echinatus and B. ornatus . From B. echinatus it differs by the short setae and broad, dense scales along the parallel-sided rostrum and elytra. From B. ornatus it differs by the depressed male 5th ventrite, median longitudinal sulcus on the epifrons, small and strongly convex eyes, vestiture grey, elytra without spotted pattern, and in the structure of genitalia.

Distribution. Poland, Hungary, Ukraine.

Bionomics. The species is found in leaf- and grass-litter of xerothermic forests.

Remarks. This species was recently placed in the subgenus Hippomias ( Białooki 2007: 164) . This placement is unacceptable because of the head and tegmen sharing the same structure with Brachysomus s. str.: rostrum parallelsided, pterygia not projecting beyond outline of rostrum, antennal scrobes distinct and reaching ventral side of rostrum, hypostomal-labial sutures appearing as two small pits, tegmen with parameres developed. The holotype and 7 paratypes are in the collection of Z. Cmoluch (UMCS), and 2 paratypes are in the collection of the Zoological Institute of the Polish Academy of Science, Warsaw.

Additional material examined. POLAND: 1♀, ‘Polonia, Biała Góra Distr., Tomaszów Lub[elski], 27.v.1982, L. Borowiec leg.’ (BRc); 1♂, ‘Polska, Wyżyna Lubelska, Rez. Grodek, k. Hrubieszova, 6.vi.1971, B. Pertiszak’ (MMc); 1♀, SE Poland, Czumow, E Hrubieszow, 7.vi.1997, M. Wanat leg. (MMc). HUNGARY: 1♀, ‘Hung.[aria], Baranya m., Negyharsány, Szársomlyó, 300 m, 4.vi.1984, Ádám leg.’ (HNHM). UKRAINE: 2♂, 3♀, Kyiv, Lysa Hora locality, meadow, near Cytisus , pitfall traps, 2–11.vi.2000 V.Yu. Nazarenko (SIZK); 1♂, idem, 12–21.v.2000 V.Yu. Nazarenko leg. (SIZK); 1♂, 2♀, idem, 9–26.v.2001 and 26.v.2001 V.Yu. Nazarenko (SIZK).

Figures

FIGURE 182. Brachysomus strawinskii: A: aedeagus, dorsal and lateral view; B: tegmen; C: spermatheca; D: epistome; E: tergite VIII.

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

FIGURES 37–42. Brachysomus, dorsal habitus: 37, 38: B. echinatus. 39: B. strawinskii 40: idem, female. 41: B. ornatus, male. 42:—idem, female.

FIGURES 87–94. Brachysomus, details: 87, 88: B. echinatus. 89, 90: B. ornatus. 91, 92: B. strawinskii. 93, 94: B. fremuthi.