Brachysomus (Hippomias) transsylvanicus ( Seidlitz, 1868 )

Yunakov, Nikolai, 2022, A review of the genus Brachysomus Schoenherr (Coleoptera: Curculionidae: Entiminae), Zootaxa 5193 (1), pp. 1-165 : 62-63

Brachysomus (Hippomias) transsylvanicus ( Seidlitz, 1868)

Figs. 43 , 112, 113 , 218 , 239B

Platytarsus transsylvanicus Seidlitz, 1868: 90 . Type locality: Romania, Dobruja; Formánek, 1905: 175; Dalla Torre et al., 1937: 175; Košťál, 1992: 40; Białooki 2007: 164.

Brachysomus solarii Formánek, 1906: 38 . Type locality: Romania, Dobruja: Košťál 1992: 36.

Redescription. Measurements: Body length 1.95–2.55 mm, width 1.15–1.55 mm. Colouration: Body, legs and antennae brown. Vestiture: Body covered with recumbent scales and erect, oblong-lanceolate setae. Scales grayishbrown, oval, excised at apex, densely covering upper side of body and external surface of femora. Setae at pronotum suberect, at elytra erect, forming 1–2 straight dense rows at interstriae, as long as 0.5 of interstrial width. Antennal funicle with thin sparse hairs. Antennal scape, tibiae, and tarsi with dense hairs and widened setae.

Head: Rostrum conical, weakly narrowing to basal third, continuing parallel-sided to apex, as long as wide (RL/ RW = 1.00–1.09). Pterygia well visible from above, not projecting from outline of rostrum. Epifrons parallel-sided, distinctly convex longitudinally, separated from vertex by transverse depression. Vertex flat. Eyes small (VW/ELD in males = 2.30; in females = 2.50–2.60), oval, gently convex, situated slightly lower than level of vertex. Antennae: scape weakly curved, evenly widened distally; funicular antennomeres: 1st and 2nd elongate, 1st 1.5x as long as 2nd; 3rd as long as wide; 4 th –7th transverse. Club egg-shaped, weakly set off from funicle; 1st club antennomere trapeziform, evenly widened.

Thorax: Pronotum moderately transverse (PL/PW = 0.70–0.78), strongly convex at sides, constricted near anterior margin; disc almost flat, finely, densely, and shallowly punctate. Elytra: oval or broad-oval, weakly convex at sides and disc, widest at middle (EL/EW = 1.16–1.23). Basal margin of elytra weakly concave. Striae narrow, deep, punctures weakly separated, 1.5–2.0x narrower than interstriae; spaces between punctures situated distinctly lower than level of interstriae. Interstriae shiny, weakly convex. Legs: Femora distinctly swollen in middle part; tibiae straight externally and weakly sinuate internally. Hind tibiae in male weakly sinuate at apical third and weakly mucronate. Second tarsomere strongly transverse, 3rd with broad lobes. Fifth fore tarsomere extending beyond apical lobes of 3rd by length of the lobes.

Abdomen: Anterior margin of 1st ventrite concave. Male 5th ventrite evenly strongly convex, without subapical depression, with apical margin obtuse, in females moderately rounded. Male genitalia: Median lobe moderately sclerotized, weakly widened in basal half; endophallus with dense worm-shaped spiculate field and bifurcate endophallic sclerite. Ventral membranes distinctly extended beyond base of endophallus. Spermatheca: with large ramus and vestigial collum, corpus normal.

Diagnosis. Brachysomus transsylvanicus is closely related to B. laticollis , differing by a weaker transverse and a weaker convex pronotum (PL/PW = 0.70–0.78, in B. laticollis 0.56–0.65); pterygia not projecting from outline of rostrum, eyes small (VW/ELD in males = 2.30, in females = 2.50–2.60), very dense rows of setae at interstriae of elytra; hind male tibiae weakly sinuate in apical third and structure of aedeagus.

Distribution. Romania (Dobruja).

Bionomics. Brachysomus transsylvanicus has been collected in leaf litter of Fagus forest and on dry slopes in leaf litter of Tilia forests ( Białooki, 2007).

Remarks. Lectotype, ♂ (SZM) designated by M. Košťál (1992).

Additional material examined. ROMANIA: 12♂; 26♀, ‘Klst. Kokos, Dobrutscha, Breit’ (ZMAN, ZMUH, ZMUN, KUMN, NMPC, MTD); 3♂, 4♀ ‘Nd. Dobrud., Rum. Kuchta’ (ZMUH, HNHM, NHMUK).

Figures

FIGURE 218. Brachysomus transsylvanicus: A: aedeagus; B: tegmen; C: spermatheca; D: setae of elytra; E: hind tibia of male; F: scales of elytra.

FIGURE 239. Occurrence map of Brachysomus: A: Brachysomus s. str.; B: subgenus Hippomias.

FIGURES 43–50. Brachysomus, dorsal habitus: 43: B. transsylvanicus. 44: B. carpathicus female. 45: B. laticollis. 46: B. carpathicus male. 47: B. ellipticus. 48: B. kubanensis. 49: B. verae. 50: B. kovali.

FIGURES 112–117. Brachysomus, details: 112: B. transsylvanicus, head dorsal view. 113: B. transsylvanicus, head lateral view 114: B. carpathicus, head dorsal view. 115: B. carpathicus, head lateral view. 116: B. laticollis, head dorsal view. 117: idem, lateral view.