Brachysomus (Hippomias) xanthianus, Christoph Germann, Carlo Braunert, George Kakiopoulos & George Kakiopoulos, 2016

Christoph Germann, Carlo Braunert, George Kakiopoulos & George Kakiopoulos, 2016, Brachysomus (Hippomias) xanthianus sp. n. from Thrace, Greece (Coleoptera, Curculionidae), Mitteilungen der Schweizerischen Entomologischen Gesellschaft 89, pp. 177-182 : 178-182

publication ID	https://doi.org/ 10.5281/zenodo.192629
DOI	https://doi.org/10.5281/zenodo.5608841
persistent identifier	https://treatment.plazi.org/id/9248312E-3D74-E95A-2B2B-2658FEE66AE6
treatment provided by	Plazi
scientific name	Brachysomus (Hippomias) xanthianus
status	sp. nov.

Treatment

Brachysomus (Hippomias) xanthianus View in CoL sp. n.

( Figs 1-3 View Fig. 1 View Fig. 2 View Fig. 3 )

Material. Holotype: ♁ 284_16.10 GREECE, Mt. Xanthi, W-Xanthi , N41°11’56” / E24°45’28”, 660 m, Kalk, offene Wäldchen, [limestone, open forest] 26.5.2016, leg. C. Germann. Red label: Holotype Brachysomus (Hippomias) xanthianus sp. n. des. Germann, Braunert &Kakiopoulos 2016 ( NMBE). GoogleMaps

Paratypes: 12 ♁♁,4 ♀♀,same data as holotype (cCG, cRB, cGK, NMSO). 13 ♁♁, 6 ♀♀,«2016-19 GREECE, Mt. Xanthi, W-Xanthi, N41°11’25”/ E 24°46’23”,820m, Kalk, artenreiche Bergwiese mit Gebüschsaum, [limestone, meadow with high diversity of plants]26.5.2016, leg. C. Braunert» (cCB). All with red labels: Paratype Brachysomus (Hippomias) xanthianus sp. n. des. Germann, Braunert &Kakiopoulos 2016

Description.

Size: males 1.4–1.6 mm; females 1.7–1.9 mm; holotype: 1.5 mm. Habitus: Figs 1A View Fig. 1 –B. Colour: dark brown, antennae, and legs auburn.

Head, rostrum and antennae: head with temples as long as diameter of eye, rostrum as long as wide, vertex almost twice as wide as epifrons between antennae. Epifrons in lateral view strongly bulged in middle, in dorsal view weakly carinate apically. Head with transverse impression at frons. Pterygia clearly visible in dorsal view, parallel sided. Antennal scrobe distinct, margins diverging to eye in lateral view. Eyes bulged, on upper side of head. Head and rostrum irregularly and coarsely punctate. Vestiture consisting of very short, oval bristles. Antennal scape bowed and clubbed, twice as long as width of epistome. Antennal funiculus consisting of 7segments. First and second segment as long as wide, following 5segments transverse, constantly broadening, club egg-shaped, 1.5 times wider than last segment. Antennal segments and club set with whitish hairs.

Pronotum: transverse (length/width: 0.7–0.75) widest in the middle, laterally strongly rounded, irregularly and coarsely punctate, interspaces between punctures reduced to small ridges. Vestiture consisting of oval, clubbed, recumbent, whitish bristles. Scutellum not visible.

Elytra: long-oval (length/width: 1.34 to 1.38 in males) to broader oval (length/width: 1.4 to 1.47 in females), widest in or just behind middle, rounded to basis (apterous) and apex. In lateral view flattened at disc, regularly rounded at decline. Striae regularly punctate. Intervals about twice as wide as striae, glabrous, faintly and irregularly punctate. Intervals set with both, one row of clubbed, oval recumbent bristles, and sparsely standing, much smaller, narrow, attached or weakly bowed scales.

Underside: Vestiture sparse with similar narrow, attached or weakly bowed scales as on intervals. Apical edge of 5th ventrite in males almost straight, in females half-round.

Legs: femora edentate, strongly swollen in middle. Tibiae strong, weakly sshaped at inner margin, all with rows of reddish spines at apex. Metatibiae in male weakly mucronate. Four visible strong tarsal segments; first broadly triangular, second transverse, third bilobed, claw segment gracile and elongate almost as long as the preceding three segments together, claws simple. Vestiture consisting of oval, clubbed, recumbent whitish scales.

Male genitalia: Figs 2 View Fig. 2 A–B. Penis elongate, tip triangular with blunt apex, flattened in dorsal/ventral view. Apodeme one fourth longer than median lobus. Penis dorsally weakly sclerotized. No visible sclerites in the internal sac, but containing aspiculate field. Tegmen without parameres, tegminal apodeme slightly bowed, half as long as apodeme of aedeagus.

Female genitalia: Figs 2 View Fig. 2 C–E. C. Sternite VIII with long and slender apodeme and anarrow, scarcely sclerotized lamella, setose at fore margin. D. Spermatheca with very long C-shaped cornu, small globular nodulus and bigger globular ramus. E. Ovipositor with one pair of weakly sclerotized segments, without styli, set with long sensillae.

Sexual dimorphism: small differences; males have amore long-oval body (females more rounded oval), the base of the 10th elytral interval is more strongly depressed (thus more angular in lateral view) and metatibiae are faintly mucronate (not in females).

Etymology:The new species’ epithet “ xanthianus ”derives from Mount Xanthi where it was discovered.

Ecology: Brachysomus xanthianus sp. n. was sifted from mosses, leaf litter, plant debris, and cushion plants together with the weevils Omias sandneri Reitter, 1906 , Stomodes Schönherr, 1826 sp., Stuebenius romani (Fremuth, 1992) , Styphlus jonicus (Reitter, 1899) and Trachyphloeus alternans Gyllenhal, 1834 ( Fig. 3 View Fig. 3 ). The habitat consisted of alow Quercus ilex and Juniperus forest and arich herbaceous cover growing on xerothermic limestone outcrops near the top of Mount Xanthi at altitudes between 660 and 820 ma.s.l.

DIAGNOSIS AND DISCUSSION

Brachysomus xanthianus sp. n. is at present one of the smallest species of the whole genus with solely 1.4–1.9 mm (other small species are B. (Hippomias) subtilis Yunakov, 2006 with 1.5–2.3 mm, and B. (Hippomias) merkli Yunakov, 2006 with 1.6– 2.2 mm), and combined with the very scarce and short vestiture and the dark brown body colour well recognisable. Based on the shape of the rostrum (see above) it clearly belongs to the subgenus Hippomias,and there it shares similarities with both, the B. transsylvanicus (Seidlitz, 1868) species group by Košťál (1992), and the B. ponticus Apfelbeck, 1899 species group sensu Yunakov (2006).

In the first species group, the general habitus of B. tenuicollis Yunakov, 2006 with arather elongate body, the relatively sparse vestiture, and the shape of the rostrum is similar ( B. xanthianus sp. n. is much smaller, it has even scarcer vestiture with shorter bristles, and head with rostrum more broadly triangular, eyes more protruding, transverse depression at frons deeper). Furthermore, B. armatus Yunakov, 2006 shows similarly transverse antennal segments 3–7, but differs in the strongly s-shaped metatibiae, and their sharp inner face at apex. The similarly minute B. merkli shows asimilar body shape, especially head and pronotum, but differs in the stronger punctate striae on the elytra, the much longer elytral bristles, and the less transverse antennal segments.

In the second species group, B. fallax Yunakov, 2006 with the protruding eyes situated high on the head, the rostral sulcus, the recumbent setae on the elytra and the shape of the penis is similar (just weakly carinate rostrum, and elytra not strongly rounded in B. xanthianus sp. n.). Additionally B. samos Yunakov &Germann 2012 shows similarities regarding the shape of rostrum, but the eyes are much flatter, the antennal segments 3–7 are as long as wide, the body vestiture is denser, the shape of the scales is different, and the base of 10th elytral interval is more strongly depressed in males.