Eurosphalmus (Eurosphalmus) tenuicollis ( Yunakov, 2006 ) Yunakov, 2022

Yunakov, Nikolai, 2022, A review of the genus Brachysomus Schoenherr (Coleoptera: Curculionidae: Entiminae), Zootaxa 5193 (1), pp. 1-165 : 75-76

Eurosphalmus (Eurosphalmus) tenuicollis ( Yunakov, 2006) comb. n.

Figs. 135 , 231

Brachysomus tenuicollis Yunakov, 2006: 312 . Type locality: Hungary, Telkibánya?

Remarks. This species was known from only one female and assigned to the subgenus Hippomias of Brachysomus ( Yunakov 2006) . Recent examination of additional material, including males, allows for better recognizing the generic placement of this species.

The following synapomorphies of Eurosphalmus were found in B. tenuicollis : 1) aedeagus with distinct subapical lobes, 2) median lobe membranous on ventral side, extremely short (length 0.3x that of apodemes), 3) ventral membranes strongly projecting, 4) spermatheca with collum reduced and ramus very large.

Diagnosis. From E. attilai Yunakov & Nadein, 2006 this species differs by a deeply sinuate male hind tibia, less distinct subapical lobes of aedeagus, slightly developed median longitudinal sulcus at epifrons. This species is also similar to Brachysomus merkli and B. polonicus and has been mistakenly placed in Brachysomus ( Yunakov, 2006) . From B. merkli it differs by shorter, erect, spatulate setae (as long as 1/2–1/3width of interstriae); body densely covered with lanceolate scales; antennae thicker: 4 th –7th funicular antennomeres transverse, (in B. merkli 4 th –7th as long as wide). Tarsi wider and shorter, 5th fore tarsomere extending beyond apical lobes of 3rd by 0.81 length of the lobes. Posterior margin of 1st ventrite almost straight, in the middle slightly sinuate (in B. merkli strongly sinuate). From B. polonicus it differs by a less transverse pronotum that is evenly convex at sides (PL/PW = 0.81; in females of B. polonicus PL /PW = 0.70–0.72), widest at middle, base of elytra clearly wider than base of pronotum (in B. polonicus widest at basal 1/3, base of elytra as wide as base of pronotum).

Redescription. Measurements: Body length 2.05–2.50 mm, width 1.07–1,37 mm. Vestiture: Body dark-brown, antennae and legs brown. Head, pronotum, and elytra evenly covered with both narrow-lanceolate and excised apically, small, light scales and spatulate suberect setae. Legs and antennae with thin, acute setae and hairs. Setae as long as 1/2–1/3 width of interstriae.

Head: Rostrum conical, slightly elongate (RL/RW = 1.06–1.13). Pterygia clearly visible in dorsal view, in male strongly projecting from outline of rostrum, in female slightly projecting. Epifrons flat, at basal 1/3 narrowing, then parallel-sided to apex, from antennal insertion weakly widened apically, not separated from vertex by transverse depression.Vertex flat, broad.Epistome depressed.Eyes small(VW/ELD =2.33–2.70), oval, strongly hemispherically convex. Antennae: Scape in female weakly and evenly curved and widened distally; in male sharply widened in distal third, at apex 3x wider than at base; funicular antennomeres: 1st and 2nd elongate, 1st (L/W = 1.4) thicker than 2nd (L/W = 1.3); 3rd as long as wide, 4 th –7th transverse; club egg-shaped, clearly separated from funicle.

Thorax: Pronotum transverse (PL/PW = 0.74–0.81), evenly convex at sides, widest at middle, slightly constricted near anterior margin. Disc in female flat longitudinally and weakly convex transversally, in male distinctly convex; finely and densely punctate, granulate at sides, without lateral depression. Elytra: oval (EL/EW = 1.29–1.30), evenly and weakly convex at sides. Disc gently convex longitudinally and in cross-section. Striae linear. Interstriae flat, broad, 2.5x as wide as striae. Punctures small, shallow, weakly separated; spaces between punctures somewhat narrower than diameter of puncture, situated deeper than interstrial level. Base noticeably sinuate, clearly wider than base of pronotum. Legs: Femora in female moderately swollen in middle part, in male sharply swollen. External margin of female fore tibiae straight, external apical angle weakly projecting from contour of fore tibia. Male fore tibiae in external apical angle not projecting from contour. Hind male tibiae deeply sinuate and densely pilose internally. Mucro very short, weakly visible under subapical pilosity. First tarsomere triangular, 2nd strongly transverse. Fifth fore tarsomere extending beyond apical lobes of 3rd by 0.81 length of the lobes.

Abdomen: Posterior margin of 1st ventrite almost straight, slightly sinuate at middle. Female 5th ventrite flat, apical margin rounded. Male 5th ventrite slightly convex, apical margin straight. Male genitalia: Aedeagus with well-developed subapical lobes. Ventral membranes strongly pronounced.

Spermatheca with large ramus.

Bionomics. This is a rare species, inhabiting leaf litter in Fagus sylvatica forests in the low hills of the Cserhegy Mountain Range. The beetles have been collected using a Winkler sifter in leaf litter.

Type material. HUNGARY: Holotype ♀, ‘Telkibánya, Cser-hegy; 1989.V. 24. leg. G. Hegyessy / coll. A. Podlussány’ ‘Holotype │ Brachysomus tenuicollis Yunakov des.’ (HNHM).

Additional material examined. HUNGARY: 1♂, ‘Hungaria or., Telkibánya, Cser-hg., 3.vi.2006, J. Krátký leg.’ │ coll.A. Podlussány, (HNHM); 1♂, 1♀, Hungaria, Baz megye, Telkibánya, Cser-hegy, in leaf litter; 27.v.2008, A. Podlussány & G. Hegyessy leg. │ coll. A. Podlussány, (HNHM). SLOVAKIA: 1♂, ‘Kisazar (Malé Ozerovce), Hungaria │ ex coll. Dr. C. Chyzer’, (HNHM). UKRAINE: Dnipro Prov., Kryvyi Rih, Veseli Terny Park, 22.vi.2012, pitfall trap, N.N. Isupova leg. (SIZK).

Figures

FIGURE 231. Eurosphalmus tenuicollis comb. n.: A: aedeagus; B: tegmen; C: spermatheca; D: antenna; E: tarsus; F: scales of elytra.

FIGURES 130–135. Brachysomus, main view. 130: B. alexeevi. 131: B. argutus 132: B. armatus 133: B. boroveci 134: B. pelex. 135: Eurosphalmus tenuicollis comb. n.