Heisonyx giustocaroli, Borovec & Colonnelli & Osella, 2009

Borovec, Roman, Colonnelli, Enzo & Osella, Giuseppe, 2009, On the South African genus Heisonyx (Coleoptera: Curculionidae: Entiminae), Acta Entomologica Musei Nationalis Pragae 49 (2), pp. 841-860 : 851-852

Heisonyx giustocaroli sp. nov.

( Fig. 8 )

Type material. HOLOTYPE: ♀ ( ECRI, to be deposited in MZUR in future), ‘ South Africa, W Cape, Cape Town, Kirstenbosch , 33.58.35 S 18.26 .15 E, 400 m, 23.XI.2007, E. Colonnelli lgt.’

Description. Body length: 2.8 mm.

Integument black, antennae, tibiae and tarsi rusty-red. Whole body very densely covered by round recumbent scales. Vestiture on elytra grey with nebulose pattern of brown large spots, light grey scales forming a spot on elytral intervals 6 and 7 at base and a stripe on interval 10, pronotum brownish with rather wide, curved whitish-grey lateral stripe along each side and a trace of median light grey longitudinal band ( Fig. 8 ). Head and rostrum with greyish scales. Semierect clavate elytral scales about as long as half of the width of one interval and about as wide as the diameter of one recumbent scale; the latter clearly longer and more erect at base of intervals 5–7. Similar rather long erect scales scattered on pronotum and head. Femora, tibiae and antennal scape covered by recumbent and semierect seta-like scales smaller than those on elytra; tarsi, funicle and club devoid of recumbent scales.

Rostrum convex, quite short, 1.33 times as wide as long, feebly tapered anteriad. Epifrons tapered towards apex, with rather feebly concave sides, at base slightly narrower than distance between anterior margins of eyes, longitudinally depressed along midline, separated from the rest of head by deep transverse V-shaped groove, separating in lateral view rostrum from the rest of head. Antennal scrobes in dorsal view clearly visible for a little more than apical two thirds of rostrum, in lateral view feebly curved, moderately enlarged distally, their dorsal margin directed toward upper border of eye and ventral margin toward middle of eye. Eyes very large, rather strongly protruding from outline of head.

Antennae slender. Scape distinctly curved, apical third gradually and rather moderately thickened toward apex. Funicle 7-segmented, first funicular antennomere 1.5 times as long as wide, 1.5 times longer than funicular antennomere 2, the latter 1.65 times as long as wide, funicular antennomeres 3–6 moniliform and about as wide as long, funicular antennomere 7 not transverse, club fusiform and elongate, 2.28 times as long as wide.

Pronotum 1.5 times as wide as long, widest behind middle, in anterior half a little constricted. Disc in lateral view moderately convex.

Elytra elongate-oval, 1.33 times as long as wide, widest in middle, with moderately rounded sides. Intervals almost flat, striae very narrow, line-shaped.

Tibiae moderately elongate, apex of protibia straight and truncate with enlarged internal margin and very slightly arcuate lateral margin, with single hook-shaped spine at inner angle and some fine translucent bristles at apex. Tarsi comparatively elongate, tarsomere 2 about as wide as long, tarsomere 3 1.4 times as wide as long and 1.8 times as wide as tarsomere 2, ungular tarsomere very elongate, twice as long as tarsomere 3 and surpassing it by 1.28 times the length of tarsomere 3; claw brownish with rudimentary trace of second claw in the form of minute basal black spur. Fore tarsi and left middle tibia and tarsus missing in the holotype.

Genitalia. Spermatheca not examined. Ovipositor with almost triangular, apically tapered hemisternite, at apex obliquely subtruncate with long and slender styli with apical setae, shape very similar to that of H. jelineki sp. nov. ( Fig. 26 ).

Differential diagnosis. The new species is close to both H. vitticollis and H. jelineki sp. nov., with which it shares the 7-segmented funicle. Differences from H. vitticollis are the same listed in the key below. Heisonyx giustocaroli sp. nov. can be distinguished from the very similar H. jelineki sp. nov. by the larger size (2.8 mm instead of 1.7–2.6 mm), blackish colour of the femora contrasting with the rusty-red tibiae, narrower rostrum (1.33 times instead of 1.38–1.53 times as wide as long), elongate antenna with funicular segment 7 not transverse, the presence of a deep groove separating the rostrum from the rest of head, larger and more convex eyes, more elongate elytra (1.33 times instead of 1.19–1.26 times as long as wide), different pronotal and elytral colour pattern, the presence of a single hook at the inner apex of protibia, elongate tarsal segment 4 and the minute basal spur on the claws.

Etymology. This new species is named after Carlo Giusto (Varazze (Savona), Italy), who was of great help when collecting together in South Africa, to commemorate our friendship.

Bionomics. The holotype was collected from a tussock of grass at the edge of a path at a small forest clearing.

Distribution. South Africa: Western Cape.

Figures

Figs. 8–9. Habitus. 8 – Heisonyx giustocaroli sp. nov., holotype; 9 – H. jelineki sp. nov., paratype. Scale bar: 1 mm.

Figs. 16–27. Protibia and female genitalia. 16–19 – Heisonyx vitticollis sp. nov., paralectotype: 16 – right protibia, 17 – ovipositor, 18 – spermatheca, 19 – sternum 8 in female; 20–21 – H. barclayi sp. nov.: 20 – ovipositor, 21 – spermatheca; 22 – H. danielssoni sp. nov., spermatheca; 23 – H. fuscus sp. nov., ovipositor; 24–25 – H. hexarthrum sp. nov.: 24 – ovipositor, 25 – spermatheca; 26–27 – H. jelineki sp. nov.: 26 – ovipositor, 27 – spermatheca. Scale bars: 0.25 mm (a – sternum 8; b – ovipositor and spermatheca; c – protibia).