Brachysomus (Brachysomus) frivaldszkyi ( Reitter, 1884 )

Yunakov, Nikolai, 2022, A review of the genus Brachysomus Schoenherr (Coleoptera: Curculionidae: Entiminae), Zootaxa 5193 (1), pp. 1-165 : 34-35

Brachysomus (Brachysomus) frivaldszkyi ( Reitter, 1884)

Fig. 27, 28 , 73, 74 , 190 , 238A

Platytarsus frivaldszkyi Reitter, 1884: 259 .) Type locality: Romania, Mehadia; Dalla Torre et al. 1937: 173; Košťál 1991b: 82.

Redescription. Measurements: Body length 2.10–2.60 mm, width 1.25–1.75 mm. Colouration: Body brown, antennae and legs yellowish-brown. Vestiture: Head (except epistome), body, and legs densely covered with light, weakly pearly, small, spatulate, and oval scales. Vestiture of sides of pronotum denser than at disc. Elytral interstriae with one or two rows of short, apically widened, rounded, strongly erected, light setae, their length 0.5x of width of interstriae. Ventrites covered with hairs and hair-like scales. Legs with same kind of scales and more elongate setae. Antennal scape with long setae, funicular antennomeres and club with thin, pale hairs.

Head: Rostrum as long as wide, weakly narrowed from base to middle (L/W = 1.06). Antennal sockets partly visible in dorsal view. Pterygia not projecting from outline of rostrum. Antennal scrobes sharply developed, deep, directed to ventral margin of eye, reaching ventral side of rostrum. Epistome delimited from epifrons by thin, Ushaped carina. Epifrons weakly apically narrowed, flat, with thin median carina, without median longitudinal sulcus, not separated from vertex by transverse depression; lateral margins weakly convex. Vertex weakly convex, finely densely punctate. Eyes broad-oval [VW/ELD = 2.0–2.2 (2.1)], strongly convex, highest posteriorly. Antennae: scape gently curved, strongly widened along distal 1/3; funicular antennomeres: 1st and 2nd elongate, L/W = 2.5; 2nd L/W = 1.6; 3rd–7th moniliform, as long as wide; club spindle-shaped.

Thorax: Pronotum transverse [PL/PW = 0.72–0.77 (0.74)], widest at middle, gently and evenly convex at disc and sides, weakly constricted anteriorly and posteriorly, densely finely punctate. Elytra: oval or globose [EL/ EW= 1.14–1.23], strongly convex at disc and sides. Elytral interstriae weakly convex, shiny, 2x wider than striae. Punctures broadly separated;. Legs: Fore tibiae straight, with apical external angle not protruding. Hind tibiae weakly mucronate. Second tarsomere weakly transverse. 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 evenly strongly convex, apical margin truncate, with bilateral bunches of pale hairs. Female 5th ventrite Male genitalia: Aedeagus slightly and evenly sclerotized. Median lobe 0.5x as long as apodemes, parallel-sided along basal 2/3, narrowed along apical 1/3, apex attenuate. Endophallus with fine, elongate, and robust spicules. Ventral membranes rounded, transparent. Spermatheca: ramus and collum connate at base.

Diagnosis. Brachysomus frivaldszkyi is very similar to B. lituratus and B. frumuthi . From B. lituratus it differs by the unicoloured vestiture, without brown spots on the elytra and pronotum, the curved antennal scape, the long and erect setae on the elytral interstriae and the base of the rostrum with large swelling before the eyes. From B. fremuthi this species differs by the weakly sinuate internally male hind tibiae, spatulate and oval scales on the body, flat 5th ventrite and swelling before eyes.

Distribution. Banat-Pannonian endemic species ( Košťál 1991). Hungary (Budapest, Kamaraerdö; Szörény), Romania (South Carpathians: Mehadia; Mehedinţi Mountain Range; Caraş-Severin), Serbia.

Bionomics. This species inhabits leaf litter in deciduous forest.

Type material. Lectotype,♂ (HNHM), (designation: Košťál, 1991) with following labels: ‘Mehadia’, ‘Banat, Mehadia’, Holotypus Platytarsus Frivaldszkyi m.’, ‘Coll. Reitter’. Paralectotypes (HNHM): 2♂ ‘Banat, Mehadia’, ‘Paratypus Platytarsus Frivaldszkyi Reitter 1884 ’, ‘ Brachysomus hispidus ,’ ‘67640’; 2♀, ‘Ungarn, Banat, Reitter’, ‘Paratypus Platytarsus Frivaldszkyi Reitter 1884 ’, ‘Frivaldszkyi m. Typ.’, ‘Coll. Reitter’.

Additional material examined. ROMANIA: 7♂, 4♀, ‘Zlatica [= Zlatiţa, Caraş-Severin], 7.vi.1886’ (HNHM); 1♂, ‘Herkulesbad (= Băily Herculane), Ganglbauer leg., 1895’ (ZMUH); 1♂, ‘Herkulesbad, 1913.vii.2’, ‘coll. Dr. J. Fodor’ (HNHM); 2♂, ‘Herkulesbad / Deubel’ (NMBE); 1♀, ‘Transsylvania’ (NHMUK); 1♀, ‘Mazura [Mt.], Baziás [= Baziaş, Caraş-Severin], 6.1913’ (NMPC). SERBIA: 1♀, ‘Plavisevicza’ (HNHM).

Figures

FIGURE 190. Brachysomus frivaldszkyi: A: body; B: aedeagus, dorsal and lateral view; C: tegmen; D: spermatheca; E: tergite VIII.

FIGURE 238. Occurrence map of Brachysomus s. str.

FIGURES 25–30. Brachysomus, dorsal habitus: 25: B. subnudus, male. 26: B. subnudus, female. 27: B. frivaldszkyi, male. 28: B. frivaldszkyi, female. 29: B. lituratus, male. 30: B. lituratus, female.

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