Heisonyx oberprieleri Borovec 2019, sp. nov.
Creators: name: Borovec, Roman
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Curculionidae
Heisonyx
Heisonyx oberprieleri

description: Heisonyx oberprieleri sp. nov.
(Figs 2, 14–19) http://zoobank.org/ urn:lsid:zoobank.org:act: BDE8F681-DAE6-4792-931F-D9EB0D65FD9A
Type locality. South Africa, Western Cape, Knysna.
Type material. Holotype: ♂, ‘ SOUTH AFRICA, C.P. [Western Cape], Knysna, 34.02S 23.03E, 26.xi.1983, R. Oberprieler [lgt.]’ (SANC). Paratypes: 1 ♂ 2 ♀♀, the same data as holotype (SANC).
Description. Body length males 1.73–1.76 mm, females 2.05–2.13 mm, holotype 1.76 mm. Integument blackish, antennal scapes and funicles and tibiae rusty reddish. Elytra densely covered by rounded appressed scales which are finely longitudinally striate, 4–5 across the width of one interval, completely concealing the integument. Pronotum, head including rostrum, antennal scapes, femora and tibiae densely covered by almost identical appressed scales. Colour of vestiture varying from pale grey to brownish with an indistinct greenish sheen (Fig. 2); two specimens with a whitish spot behind the scutellum and a slender, V-shaped transverse stripe in anterior third. Elytra each with one regular row of sparse, semi-appressed, subspatulate setae, about the length of half the width of one interval; pronotum and head, including rostrum, with similar setae to those on elytra, but slightly shorter and irregularly scattered. Scapes, femora and tibiae with semi-appressed, sparse, slender, elongate-ovate setae. Funicles and tarsi with inconspicuous, short, semi-appressed setae.
Rostrum (Figs 14, 15) short, in males 1.47–1.53× and in females 1.63–1.69× wider than long, tapering slightly anteriad with sides almost straight, basally 1.02–1.05× wider than apically, laterally domed, and separated from head by shallow transverse sulcus. Epifrons in very short basal part tapering distinctly anteriad, slightly rounded to straight laterally, narrow, 0.6× the width of the rostrum at the same place, indistinctly longitudinally impressed along the midline. Antennal scrobes pit-shaped dorsally, distictly visible in apical two thirds; in lateral view slightly curved, enlarged posteriad, but not reaching eyes, the dorsal borders of the scrobes directed towards the dorsal border of eyes and their ventral borders directed to the middle of eyes. Eyes large, slightly larger in males than in females, dorsally convex, protruding slightly from outline of the head, in males about three quarters the length of the rostrum; laterally placed in the dorsal half of the head. Head short and broad, flat.
Antennae moderately robust (Fig. 2). Scapes distinctly curved at mid-length, 4.0–4.3× longer than apical breadth, regularly enlarged in apical third, as broad as clubs apically. Funicles 7-segmented, segment 1 robust, conical, 1.4–1.5× longer than broad, 1.6–1.8× longer than segment 2, which is slender and 1.3–1.4× longer than broad; segments 3–5 1.2–1.3× broader than long; segment 6 1.3× broader than long; segment 7 1.3–1.4× broader than long; clubs 1.8–2.0× longer than broad.
Pronotum (Fig. 2) 1.33–1.44× broader than long, broadest behind the middle, tapering more anteriad than posteriad; disc regularly domed; base indistinctly arched.
Elytra (Fig. 2) oval, 1.27–1.29× longer than broad, broadest at mid-length, distinctly rounded laterally in dorsal view, tapering apically, indistinctly concave just behind the base. Intervals almost flat, broad; sutural interval at base tapering distinctly; striae narrow and line-shaped.
Tibiae robust, protibiae 4.8–5.0× longer than breadth at mid-length, inner edge distinctly sinuate, rounded apically with a fringe of fine, sparse, brownish, bristle-shaped setae and 3 short, brownish, hook-shaped mucros at the internal angle, the medial one being slightly longer than the other two. Apical surface of metatibiae glabrous, fringed externally by short stout setae; metatibial corbel very slender, almost indistinct. Tarsi short; segment 2 1.4× wider than long; segment 3 1.3× times wider than long and 1.6× wider than segment 2; onychium 0.8× the length of segment 3; claw single, long, brownish.
Dorsal aspect of penis (Fig. 16) sub-parallel and indistincly convex laterally, apex tapering evenly for a short distance apicad, subtriangular; lateral aspect slender, evenly curved and parallel-sided, only tapering apically.
Female genitalia. Spermatheca (Fig. 17) with slender curved cornu and large corpus; ramus and nodulus subtriangular, ramus twice as broad as nodulus, which is about as long as broad. Gonocoxites (Fig. 19) elongate, tapering apically, apical styli long and slender, apically setose. Sternite VIII (Fig. 18) with plate long and slender, subtriangular; apodeme moderately broad, greatest breadth at mid-length, terminating just before the apex of plate.
Derivation of name. The newly described species is dedicated to Rolf G. Oberprieler (CSIRO Canberra, Australia), collector of the type material, an excellent expert on Curculionoidea of the Afrotropical and Australian regions.
Biology. Unknown.
Differential diagnosis. The 7-segmented funicle of H. oberprieleri sp. nov. is similar to H. giustocaroli, H. jelineki Borovec, Colonnelli & Osella, 2009 and H. viticollis Marshall, 1947. Heisonyx oberprieleri can be distinguished from H. viticollis by funicle segment 1 which is 1.6–1.8× as long as segment 2, segment 2 is 1.3–1.4× as long as broad (H. viticollis has segment 1 twice as long as segment 2, segment 2 is isodiametric) and onychium 0.8× the length of segment 3 which has a brownish claw (H. viticollis has onychium 1.2× the length of segment 3 which has a blackish claw). It is possible to distinguish H. oberprieleri sp. nov. from H. giustocaroli mainly because it has a single claw (H. giustocaroli has a long slender claw with a trace of a second rudimentary claw at its base) and its rostrum is separated from the rest of the head by a very fine, indistinct line (H. giustocaroli has the rostrum separated from the rest of the head by a deep transverse sulcus). Heisonyx oberprieleri sp. nov. is thus most similar to H. jelineki, from which it can be distinguished mainly by the very differently shaped penis:
1. Funicle segment 2 in males 1.6–1.8×, in females 2.0–2.1× longer than broad. Apex of protibiae armed with fine, short, whitish setae. Apex of penis broadly obtuse, triangularly sharpened in the middle (Fig. 20)....................................................................................................... H. jelineki Borovec, Colonnelli & Osella
- Funicle segment 2 in both sexes 1.3–1.4× longer than wide. Apex of protibiae armed with brownish, bristle-shaped setae. Penis tapering evenly apicad and regularly subtriangular (Fig. 16)................................. H. oberprieleri sp. nov.
description: Published as part of Borovec, Roman, 2019, Three New South African Embrithini (Coleoptera: Curculionidae: Entiminae), pp. 259-267 in Zootaxa 4555 (2) on pages 263-264, DOI: 10.11646/zootaxa.4555.2.6, http://zenodo.org/record/2624347