Heisonyx vitticollis Marshall, 1947

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 : 844-845

Heisonyx vitticollis Marshall, 1947

( Figs. 1–3 , 10 , 16–19 )

Type material. LECTOTYPE: J ( BMNH) ( Fig. 1, 3 ) : ‘ SYNTYPE [circular label with bluish margin, printed] // S. AFRICA Grahamstown 26.III.1947 Miss M. Farquhar From soil on golf course [handwriting] // Heisonyx vitticollis, Mshl. COTYPE [Marshall’s handwriting] // G. A. K. Marshall Coll. B. M. 1950-255 [printed] // LECTOTYPUS ♂ Heisonyx vitticollis Marshall, E. Colonnelli des., 2008 [red, handwriting]’.

PARALECTOTYPES: 2♀♀ ( BMNH), the same data as lectotype ; 1J 1♀, ‘Cotype [circular label with yellow margin, printed] // Grahamstown C. P. Golf Course grass 3/4/ 47 M. F. [Marshall’s handwriting] // Curculionid 24.3.47 G. C. [7.4.47 in second specimen, Marshall’s handwriting] // Heisonyx vitticollis, Mshl. COTYPE [Marshall’s handwriting] // Pres. by Imp. Inst. Ent. B. M. 1947-357 [printed]. The appropriate labels: “ PARALECTOTYPUS ♂ (or ♀) Heisonyx vitticollis Marshall, E. Colonnelli des., 2008 [red, handwriting]’ were added.

We have examined five syntypes from Marshall’s collection ( BMNH).The lectotype is designated here.All these specimens are freshly emerged and one paralectotype is teneral with one elytron missing.

Redescription. Body length: 2.0– 2.1 mm (lectotype 2.0 mm).

Black, femora, tibiae and antennae dark brownish. Whole body covered by dense greyish scales, pronotum with four longitudinal dark brownish stripes, elytra with irregular brownish spots, one female with two indistinct, V-shaped bands in the middle and posterior third of elytra ( Fig. 1 ). Recumbent elytral scales rounded, very dense, partly overlapping, finely longitudinally striate, leaving only punctures of striae visible. Semierect elytral scales wide, clavate, slightly longer than half of elytral interval and twice as wide as the diameter of one recumbent scale, densely arranged in one row on each interval. Pronotum, head and rostrum thickly covered by the same kind of recumbent scales as those on elytra and intermingled with shorter semierect setae, head with dense row of semierect setae above each eye. Legs and antennae except club entirely covered by dense and round recumbent scales and short, scale-shaped semierect setae.

Rostrum 1.29–1.31 times as wide as long, very feebly tapered anteriad. Epifrons also feebly tapered anteriad, at base only slightly narrower than the distance between anterior edges of eyes, feebly longitudinally depressed along midline, with narrow longitudinal stria along the whole length and with very fine, sometimes barely visible V-shaped transversal stria at base. Rostrum convex, in lateral view separated from rest of head by indistinct and narrow transversal groove. Antennal scrobes in dorsal view clearly visible on anterior half of rostrum, in lateral view furrow-shaped, with distinct borders, feebly enlarged posteriad, dorsal margin subparallel with dorsal border of epifrons, ventral margin directed toward middle of eye. Eyes large, moderately convex.

Antennae robust, scape distinctly curved at midlength, gradually thickened toward apex. Funicle 7-segmented, first funicular antennomere conical, robust, 1.4 times as long as wide, twice as long as the isodiametric second funicular antennomere, all funicular antennomeres closely adpressed, funicular antennomeres 3–7 gradually widening toward club, funicular antennomere 3 and 4 1.4 times as wide as long, funicular antennomere 5 1.5 times as wide as long, funicular antennomere 6 1.6 times as wide as long, funicular antennomere 7 1.7–1.8 times as wide as long, club as wide as scape at apex.

Pronotum 1.39–1.46 times as wide as long, widest in posterior third, in anterior half strongly narrowing toward anterior margin, constricted immediately behind it. Disc in lateral view only very feebly convex.

Elytra oval, 1.21–1.23 times as long a wide, widest at middle. Intervals almost flat, striae very narrow, appearing as rows of fine punctures.

Tibiae short and robust, apex of protibia with inner margin enlarged and lateral margin rounded, apex with five short blackish spines and two hook-shaped brownish spines at inner angle and short fringe of fine and very dense black bristles on inner edge near apex ( Fig. 16 ). Tarsi short. Tarsomere 2 1.3–1.4 times as wide as long; tarsomere 3 1.4 times as wide as long and 1.2–1.3 times as long as tarsomere 2. Ungular tarsomere 1.2 times as long as tarsomere 3, claw black.

Male genitalia. Aedeagus in basal half parallel-sided, apical half triangular with straight, regularly tapering sides ( Fig. 10 ).

Female genitalia. Spermatheca C-shaped with regularly curved cornu, large corpus, short and wide nodulus and very short, wide ramus ( Fig. 18 ). Ovipositor with wide, long-oval hemisternite, apex dull with very short stylus with apical setae ( Fig. 17 ).

Differential diagnosis. Heisonyx vitticollis can be confused only with H. jelineki sp. nov. and H. giustocaroli sp. nov., both with 7-segmented antennal funicle. The distinguishing characters are given in the differential diagnoses of the latter two species and in the key.

Bionomics. MARSHALL (1947) stated in the original description: ‘The weevils were all found in soil samples taken in the upper four inches of soil on the fairway of a golf course, after the surface vegetation had been scraped away.’

Distribution. South Africa: Eastern Cape.

Figures

Figs. 1–3. Heisonyx vitticollis Marshall, 1947. 1 – habitus of the male lectotype in dorsal view; 2 – female paralectotype in lateral view; 3 – labels of the lectotype. Scale bar: 1 mm (Figs. 1, 2).

Figs. 10–15. Aedeagus. 10 – Heisonyx vitticollis Marshall, 1947, lectotype; 11 – H. barclayi sp. nov., paratype; 12 – H. danielssoni sp. nov., holotype; 13 – H. fuscus sp. nov., holotype; 14 – H. hexarthrum sp. nov., paratype; 15 – H. jelineki sp. nov., paratype. Scale bar: 0.3 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).