Brachysomus (Hippomias) oertzeni Faust, 1889

Yunakov, Nikolai, 2022, A review of the genus Brachysomus Schoenherr (Coleoptera: Curculionidae: Entiminae), Zootaxa 5193 (1), pp. 1-165 : 51

Brachysomus (Hippomias) oertzeni Faust, 1889

Figs. 51 , 108, 109 , 214D , 239B

Brachysomus oertzeni Faust, 1889: 70 . Type locality: Greece, Euboea; Formánek, 1905: 176; Dalla Torre et al., 1937: 174; Košťál, 1992: 45.

Redescription (Lectotype, ♀). Measurements: Body length 2.50 mm, width 1.45 mm. Colouration: Body, legs and antennae brown. Vestiture: Body densely covered with broad, recumbent, round, grayish-brown scales. Elytral interstriae with long, erect, obtuse setae, forming even rows, noticeably shorter in basal half of elytra than in apical half; setae at middle of elytral disc 0.5x as long as interstrial width. Apical margin of scales noticeably dentate, not overlapping. External surface of femora and tibiae densely covered with round scales, medial surface covered with thin pale hairs. Ventral side of body with pale hairs and piliform scales.

Head: Rostrum conical, narrowed from base to mid length, as long as wide. Pterygia sharply projecting from outline of rostrum.Epifrons flat, with median longitudinal sulcus, not separated from vertex by transverse depression. Vertex weakly convex, rugose. Eyes large, weakly convex, situated distinctly lower than level of vertex, VW/ELD = 2.25. Dorsal margin of antennal scrobes not reaching eye. Antennae: Scape evenly curved, sharply swollen along apical half. Funicle gradually widened distally; funicular antennomeres: 1st and 2nd elongate, 1st larger than 2nd; 3rd–7th transverse. Club egg-shaped.

Thorax: Pronotum weakly transverse, [PL/PW = 0.77–0.80 (0.79)], evenly convex at sides, finely, densely, and shallowly punctate; anterior and posterior constrictions clearly visible. Disc of pronotum weakly convex, with weak, small lateral depression. Elytra: oval or oblong-oval (EL/EW = 1.22), weakly and evenly convex at sides and disc; in males parallel-sided. Base of elytra not convex. Striae thin; punctures very small, connete, 0.3x as long as width of interstriae; interstriae flat. Mesonotum and base of elytra vertical Legs: Fore tibiae not widened at apical angle, externally straight, internally sinuate. Second tarsomere, weakly transverse; 5th fore tarsomere extending beyond apical lobes of 3rd by length of the lobes.

Abdomen: Fifth ventrite not depressed near apex, with apical margin rounded. Spermatheca: with collum acute, as long as ramus; cornu very large.

Male unknown.

Diagnosis. This species is very similar to B. ponticus in the proportions of the head and the structure of the epistomal area. It differs by the weakly convex and large eyes; flat epifrons with distinctly developed median longitudinal sulcus; epifrons not separated from vertex by transverse depression; weakly visible erect setae on pronotum; setae at middle of disc 2x shorter than width of elytral interstriae; antennal scape almost straight.

Distribution. Greece (Euboea).

Bionomics. Unknown.

Remarks. This very rare species was described from the Eubea Peninsula (Greece). It is known from the lectotype only. It is apparently similar to B. ponticus . Earlier Michael Košťál (1992) has defined specimens collected in Thessaly (Greece) as B. oertzeni . In my opinion, these specimens should be identified as a separate species, differing distinctly from B. oertzeni . Because my conception of these species differs from that by M. Košťál, B. oertzeni is redescribed here.

Material examined. Lectotype ♀ (MTD) with golden square and labels: ‘ S Euboea, Oertzen, Oertzeni Faust [handwritten]’. ‘Coll. Faust Ankauf 1900 [printed]’ ‘Type [red]’, ‘Staatliches Museum für Tierkunde, Dresden [printed]’, ‘Lectotypus Platytarsus oertzeni Faust, Košťál design., 1987 [red, handwritten]’.

Figures

FIGURE 214. Brachysomus moczarskii: A: aedeagus; B: tegmen; C: spermatheca. B. oertzeni: D: spermatheca.

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

FIGURES 51–56. Brachysomus, dorsal habitus: 51: B. oertzeni (lectotype) 52: B. moczarskii, female. 53: B. assingi, 54: B. moczarskii, male, 55: B. curvimanus. 56: B. fallax.

FIGURES 106–111. Brachysomus, details: 106: B. moczarskii, head dorsal view, 107: B. moczarskii, head lateral view. 108: B. oertzeni, head dorsal view. 109: B. oertzeni, head lateral view. 110. B. assingi, head dorsal view. 111: B. verae, head dorsal view.