Bulirschius dysommatiformis Borovec, 2025

Borovec, Roman, 2025, Two new and one enigmatic genus of Oosomini from South Africa with description of seven new species (Coleoptera: Curculionidae: Entiminae), Zootaxa 5642 (2), pp. 101-126 : 112-113

Bulirschius dysommatiformis Borovec , sp. nov.

http://zoobank.org/ urn:lsid:zoobank.org:act:1ED3AB04-1E15-474B-B6C5-5EF9C552ABA1

Figs (4, 17, 18, 30, 36)

Type locality. South Africa, Western Cape, S of Outeniqua pass.

Type material. Holotype: ♂, RSA [ South Africa], Western Cape, S of Outeniqua pass, 33°3.8′ S, 22°24.1′ E, 7.ii.2012, indigenous forest, sifting, J. Janák lgt. ( TMSA) . Paratypes: 27 specs., same data as holotype ( JJRC) ; 47 specs., South Africa, Western Cape, 2 km S of Outeniqua pass, 33°53′ S, 22°24′ E, fynbos sifting, 5.xii.2009, J. Janák lgt. ( JJRC, RBSC) ; 5 specs., South Africa, Western Cape, S Outeniqua pass, indig. forest, 33°53.8′ S, 22°24.1′ E, 730 m, 15.xi.2021, J. Janák lgt. ( JJRC) ; 13 specs., S. Afr., S. Cape [Western Cape], Mt. Outenikwa Pass , 33.53 S - 22.23 E, 4.xi.1978, E-Y: 1502, indigen. for. litter, leg. Endrödy-Younga ( TMSA) ; 38 specs., South Africa, W [Western] Cape, Bosman r. banks below Robinson pass, 33°54.6′ S, 22°1.35′ E, 22.xi.2022, J. Janák lgt. ( JJRC) ; 192 specs., South Africa, W. [Western] Cape, below Montagu pass, 33°53.25′ S, 22°25.7′ E, 24.xi.2022, ind. forest, J. Janák lgt. ( JJRC, RBSC) ; 3 specs., South Africa, Western Cape, 2 km S of Montagu Pass , 33°53′ S, 22°27′ E, 5.xii.2009, indig. forest sifting, J. Janák lgt. ( JJRC) ; 1 spec., S. Afr., S. Cape [Western Cape], George , 33.58 S - 22.28 E, 4.ix.1978, E-Y: 1832, sifted for. litter, leg. Endrödy-Younga ( TMSA) ; 31 specs., South Africa, Western Cape, near George, Keur River Bridge , 33°54′32″ S, 23°25′14″ E, 7.xi. 2005, 450 m, G. Osella leg. ( MSNV) ; 5 specs., South Africa, W [Western] Cape, Keur River Bridge, 33°54′51″ S 22°25′14″ E, 430 m, 7.xi.2005, E. Colonnelli lgt. ( ECRI) ; 1 spec., South Africa, Western Cape, Harkerville Forest, Kranshoek , 34°06′25″ S, 23°13′66″ E, 8.xi.2005, G. Osella leg. ( MSNV) .

Diagnosis. Appressed scales on dorsal part of body sparse, subtriangular, apically bifid; erect setae on dorsal part of body clavate, apically truncated, conspicuously laterally prominent; abdominal ventrites glabrous; penis apically rounded; spermatheca with collum very long, 5× as long as wide, tube-shaped.

Description. Body length 2.09–2.63 mm, holotype 2.51 mm. Body ( Fig. 4 ) dark brown, basal half of scapes, funicles with clubs, apical portions of tibiae and tarsi paler, reddish brown. Appressed scales on dorsal part of body sparse, not covering integument, leaving space between scales subequal to width of one scale; scales on elytra subtriangular, apically bifid, their emargination not reaching half of scale length, 4 across width of one interstria, on pronotum and head with rostrum scales deeply bifid, their emargination reaching half of scale length, V-shaped; femora also with deeply bifid scales, tibiae with piliform appressed setae; elytra marbled with spots of dark brownish, hardly visible spots and contrasting light spots of greenish scales with metallic sheen; pronotum with three wide longitudinal stripes from greenish spots, median stripe slightly rounded. Elytra with conspicuous erect setae, as long as width of one interstria, forming one dense row on each interstria, clavate, apically truncated, blackish, distance between two setae about as long as length of one seta; pronotum and head with rostrum with identical erect conspicuous setae, irregularly scattered, slightly shorter on head with rostrum.

Rostrum ( Figs 17, 18 ) 1.09–1.13× as wide as long, at base 1.06–1.09× as wide as at apex, in short basal part tapered anteriad, then slightly evenly enlarged apicad with almost straight sides. Epifrons narrow, subparallel-sided, at base 0.5× as wide as rostrum in relevant part, dorsally slightly longitudinally deepened. Frons long, posteriorly reaching antennal insertions, deepened, smooth. Eyes in dorsal view not prominent from outline of head. Head under scales with regular longitudinal ridges converging towards median ridge separated by narrow grooves, giving vertex a lirate appearance.

Antennal scape ( Fig. 4 ) 6.34–6.67× as long as wide at apex, in apical part 0.7–0.8× as wide as club. Funicle slender, article 1 1.8–2.0× as long as wide and 1.3× as long as article 2, this is 1.8–1.9× as long as wide; articles 3 and 4 1.1–1.2× as long as wide; articles 5 and 6 isodiametric; article 7 1.1× as wide as long; clubs 1.6–1.8× as long as wide.

Pronotum ( Fig. 4 ) 1.50–1.56× as wide as long, widest at basal third, with rounded sides, behind anterior margin slightly constricted and flattened, with anterior margin distinctly narrower than posterior one; disc regularly domed; pronotum in lateral view slightly vaulted, flat in anterior portion. Disc under scales finely, densely, regularly punctured.

Elytra ( Fig. 4 ) oval, 1.24–1.29× as long as wide, widest at midlength, with regularly rounded sides; striae somewhat deepened, punctured; subhumeral calli missing.

Tibiae moderately slender, 6.2–6.4× as long as at midlength wide; protibiae apically obliquely subtruncate, fringed with very fine yellow setae, indistinctly finely denticulate in apical half of length of inner margin; pro- and mesotibiae with short mucro, metatibiae not mucronate. Tarsi moderately slender with tarsomere 2 1.2–1.3× as wide as long; tarsomere 3 1.3–1.4× as wide as long and 1.4× as wide as tarsomere 2; onychium of protarsi 1.3–1.4× as long as tarsomere 3; of metatarsi 1.5–1.6×.

Abdominal ventrites as long as wide, glabrous, finely and sparsely punctured. Metaventral process almost twice as wide as transverse diameter of metacoxae.

Penis ( Fig. 30 ) short, widest at base, slightly evenly tapered apicad, apically rounded; in lateral view slightly curved, slender, apically rounded; endophallus with two moderately wide sclerites, one long and one short. Tegmen without parameres.

Sternite VIII with long and slender apodeme 3.5× as long as plate and moderately small isodiametric plate, apically rounded. Gonocoxites long and slender, evenly tapering apicad with short subapical styli. Spermatheca ( Fig. 36 ) irregularly curved, moderately large; cornu long, straight; corpus elongate, distinctly curved; ramus short, isodiametric; collum very long, 5× as long as wide, tube-shaped, slightly curved.

Derivation of name. The new species takes its name from its similarity to several species of the Peritelini genus Dysommatus Marshall, 1933 . Both genera share sparse, conspicuous, clavate erect setae on the entire dorsal part of the body.

Biology. Type material was collected by sifting of litter in indigenous forest.

Distribution. South Africa (Western Cape).

Differential diagnosis. Bulirschius dysommatiformis is easily distinguishable from all other species of the genus by long, erect, clavate setae on the entire dorsal part of body and also by sparse, subtriangular, slightly bifid appressed elytral scales with a week metallic sheen, scales on pronotum and head (including rostrum) deeply bifid, V-shaped.

Figures

FIGURES 1–4. Dorsal habitus. 1. Andringitrabius polymitus. 2. Holotype labels of Andringitrabius. 3. Bulirschius densatus. 4. B. dysommatiformis. Not to scale.

FIGURES 13–24. 13–24: Head including rostrum in dorsal and lateral view. 13, 14. Andringitrabius polymitus. 15, 16. Bulirschius densatus. 17, 18. B. dysommatiformis. 19, 20. B. inconspicuus. 21, 22. B. ruiterbos. 23, 24. B. tesinskyi. Scale 0.50 mm.

FIGURES 25–43. 25: Right protibia. Bulirschius tesinskyi. 26–28: Abdominal ventrites. 26. B. densatus. 27. B. ruiterbos. 28. B. tesinskyi. 29–33: Penis in dorsal view. 29. B. densatus. 30. B. dysommatiformis. 31. B. inconspicuus. 32. B. ruiterbos. 33. B. tesinskyi. 34: Tegmen. B. tesinskyi. 35–39: Spermatheca. 35. B. densatus. 36. B. dysommatiformis. 37. B. inconspicuus. 38. B. ruiterbos. 39. B. tesinskyi. 40–42: Female sternite VIII. 40. B. densatus. 41. B. inconspicuus. 42. B. tesinskyi. 43: Ovipositor. B. tesinskyi. Scale 0.50 mm for 25–28, 34, 40–43; 0.25 mm for 29–33, 35–39.