Heisonyx griseoviridis, Borovec, 2019

Borovec, Roman, 2019, Three New South African Embrithini (Coleoptera: Curculionidae: Entiminae), Zootaxa 4555 (2), pp. 259-267 : 260-263

Heisonyx griseoviridis sp. nov.

( Figs 1 , 8–13 ) http://zoobank.org/ urn:lsid:zoobank.org:act:D9CADAA0-B5E2-4881-98A9-42ACB846DC58

Type locality. South Africa, Gauteng, Esselen Park .

Type material. Holotype: ♂, ‘[ South Africa, Gauteng], Esselen Park, TP., Feb., 1948, K. H. Munro [lgt.]’ ( SANC) . Paratypes: 6 ♂♂ ♀♀, the same data as holotype ( SANC); 2 spec., the same data as holotype ( BMNH). Esselen Park is a locality situated north of Kempton Park, 26°02'8.63"S 28°14'51.56"E (Elizabeth Grobbelaar, pers. comm.) .

Description. Body length 1.69–1.98 mm, holotype 1.81 mm. Integument blackish, antennae and legs rusty reddish, medial part of femora and antennal clubs in some specimens dark brownish. The whole body, except antennal funicles and clubs and dorsal and ventral surfaces of tarsi, densely covered by regularly rounded, greenish grey, appressed scales with an indistinct metallic green sheen ( Fig. 1 ). Scales finely longitudinally striate, partially imbricate, concealing integument completely, slightly larger on elytra than on other parts of the body with 3–4 spanning the width of one interval. Elytra with one regular row of short, inconspicuous, semi-appressed, subspatulate greyish setae, setae slightly longer than diameter of one appressed scale and about equally broad, distance between two setae 3–4× longer than the length of one seta; pronotum and head, including rostrum, with setae similar to those on elytra, but shorter, irregularly scattered and hardly visible even in lateral view; scapes, femora and tibiae with short, slender, semi-appressed, inconspicuous setae; funicles and tarsi with sparse greyish piliform setae; clubs finely setose with dense appressed and sparse erect setae.

Rostrum ( Figs 8, 9 ) slender and short, 1.28–1.39× broader than long, broadest basally, base 1.15–1.19× broader than apex, tapering evenly anteriad with straight sides; domed laterally, separated slightly from head by a narrow transverse sulcus. Epifrons narrow and small, almost isodiametric, almost flat, 0.4–0.5× breadth of rostrum at the same place, significantly narrower than space between anterior margins of eyes basally with indistinctly concave sides, well separated from head by a slender, V-shaped transverse sulcus. Antennal scrobes distictly visible dorsally in anterior half of rostrum, narrowly reniform; short and narrow laterally, furrow-shaped, indistinctly curved and enlarged posteriad, directed towards middle of eyes and separated from them by a wide squamose stripe. Eyes medium-sized, distinctly domed, projecting prominently from outline of head; circular in lateral view, placed in dorsal half of rostrum. Head wide and short, forming a regular dome.

Antennae slender ( Fig. 1 ). Scapes slender, distinctly curved before mid-length, 6.3–6.6× longer than apical breadth, regularly enlarged in apical quarter, slightly narrower than clubs apically. Funicle 7-segmented; segments 1 and 2 conical, long and slender; segment 1 1.8–2.0× longer than broad and 1.4–1.6× longer than segment 2, segment 2 1.6–1.7× longer than broad; segments 3–6 1.1–1.2× broader than long; segment 7 1.2× broader long; clubs 1.7–1.8× longer than wide.

Pronotum ( Fig. 1 ) breadth, 1.51–1.59× broader than long, broadest in basal quarter with rounded sides, tapering distinctly anteriad, constricted behind anterior margin; disc regularly domed; base indistinctly arched.

Elytra ( Fig. 1 ) oval, 1.26–1.31× longer than broad, broadest at mid-length, distinctly rounded laterally and apically. Intervals broad, flat; striae narrow, line-shaped.

Tibiae moderately robust; protibiae 5.3–5.6× longer than breadth at mid-length, outer margin straight, inner margin sinuate, obliquely subtruncate near apex, enlarged towards the inside and fringed with a sparse row of fine, short, whitish setae and a single brownish mucro. Apical surface of metatibiae glabrous, fringed externally by fine, short, whitish setae; metatibial corbels indistinct. Tarsi short; segment 2 1.2–1.3× broader than long; segment 3 1.2–1.3× broader than long and 1.6–1.8× broader than segment 2; onychium short, 0.6× the length of segment 3; claw single, long, and yellow reddish.

Penis ( Fig. 10 ) moderately long, ventral aspect broadest basally, tapering evenly and indistinctly anteriad, apex slightly enlarged, rounded, with a small rounded medial tip; lateral aspect with ventral margin almost straight, dorsal margin indistinctly and evenly curved, tapering evenly apicad.

Female genitalia. Spermatheca ( Fig. 11 ) with curved cornu; slender corpus; ramus and nodulus perpendicular to each other, ramus slightly longer than broad, oval; nodulus distinctly longer than broad and distinctly longer than ramus, curving distinctly backwards. Gonocoxites ( Fig. 13 ) long, tapering evenly apicad with elongate slender apical styli bearing setae. Sternite VIII ( Fig. 12 ) with long slender plate, apex elongate and more distinctly sclerotised, and longitudinal more distinctly sclerotised arms medially; apodeme broadest at mid-length, terminating before mid-length of plate, slightly longer than plate.

Derivation of name. The newly described species takes its name from the unusual colour of its body vestiture.

Biology. Unknown.

Differential diagnosis. This is an unusual species, not only amongst species with 7-segmented funicles, but amongst all Heisonyx species. It can, however, easily be separated and differs from all other Heisonyx species by: the body vestiture which is greenish-grey with a green metallic sheen; the slender, isodiametric epifrons which is significantly narrower basally than distance between the anterior margins of the eyes; and the protibiae which only have one mucro. All three of these characters in H. griseoviridis sp. nov. are very similar to Phaylomerinthus pallipes (Fåhraeus, 1871) , P. viridulus (Fåhraeus, 1871) and one undescribed species of Phaylomerinthus , which occur in KwaZulu-Natal. Heisonyx griseoviridis sp. nov. can easily be separated from all of them by having a single tarsal claw whereas Phaylomerinthus species all have two equally long claws. It can also easily be separated from the first Phaylomerinthus species by having much shorter elytral setae, and from the latter two species by its differently shaped penis.

Figures

FIGURES 1–3. Dorsal habitus: 1—Heisonyx griseoviridis sp. n.; 2—H. oberprieleri sp. n.; 3—Porpacus wanati sp. n. Figs 4, 5, Porpacus wanati sp. n.: 4—pronotum, head with rostrum and antennae, dorsal view. 5–pronotum, head with rostrum, lateral view.

FIGURES 6–23. Structural details of Heisonyx Marshall and Porpacus Schoenherr. Figs 6, 7, Heisonyx giustocaroli Borovec, Colonnelli & Osella: 6. penis, dorsal view. Scale = 0.25 mm; 7. spermatheca. Scale = 0.125 mm. Figs 8–13, H. griseoviridis sp. n.: 8. head with rostrum, dorsal view. Scale = 0.50 mm; 9. head with rostrum, lateral view. Scale = 0.50 mm; 10. penis, dorsal view. Scale = 0.25 mm; 11. spermatheca. Scale = 0.125 mm; 12. sternite VIII of female, dorsal view. Scale = 0.50 mm; 13. ovipositor, dorsal view. Scale = 0.25 mm. Figs 14–19, H. oberprieleri sp. n.: 14. head with rostrum, dorsal view. Scale = 0.25 mm; 15. head with rostrum, lateral view. Scale = 0.25 mm; 16. penis, dorsal view. Scale = 0.25 mm; 17. spermatheca. Scale = 0.125 mm; 18. sternite VIII of female, dorsal view. Scale = 0.50 mm; 19. ovipositor, dorsal view. Scale = 0.25 mm. Fig. 20, H. jelineki Borovec, Colonnelli & Osella: penis, dorsal view. Scale = 0.25 mm. Figs 21, 22, Porpacus wanati sp. n.: 21. penis, dorsal view. Scale = 0.50 mm; 22. spermatheca. Scale = 0.50 mm. Fig. 23, P. muellerae Borovec, Colonnelli & Osella: penis, dorsal view. Scale = 0.50 mm.