Vilargus dentulicans, Stiller, 2010

Stiller, M., 2010, Revision of Vilargus Theron (Hemiptera: Cicadellidae: Deltocephalinae) from South Africa, Zootaxa 2674 (1), pp. 1-25 : 8-9

Vilargus dentulicans sp. n.

( Figs 7–9 , 52–59 ).

Diagnosis. Aedeagal shaft laterally with subbasal triangular process, about one third as long as shaft; dorsally with concave dorsal apodeme. Plate triangular with posterior medial margin truncated. Pygofer posteromedial margin, below pygofer lobe, with rounded, sclerotized, posteriad protrusion.

Etymology. Latin, dentulus, diminutive of tooth, for the small tooth on the shaft of the aedeagus.

Colour. Male. Ochraceous ( Fig. 7 , specimen from Clocolan; Fig. 8 , specimen from Rhodes, collected 2000, with few fuscous markings dorsally; Fig. 9 , specimen from Rhodes, collected 2006, with more fuscous markings dorsally).

Male. Dimensions. (n=69) Length from apex of vertex to apex of tegmina 2.0– 2.3 mm, length from apex of vertex to apex of abdomen 2.5–2.8 mm, median length of vertex 0.4 mm, length of vertex next to eye 0.3 mm, length of pronotum 0.3 mm, width of head 0.8 mm, width of pronotum 0.7–0.8 mm, diameter of ocellus 26–30 µm, ocellocular distance 30–45 µm.

Genitalia. Aedeagus dorsally, with single, acutely triangular spine, arising lateroventrally from subbasal part of shaft, spine about one third as long as shaft; shaft apex deflected slightly laterad (towards side with spine); dorsal apodeme transverse, concave ( Fig. 52 ). Aedeagus laterally, shaft C-shaped, apex angled dorsoposteriorly; gonopore subapical, ventral ( Fig. 53 ). Connective with arms asymmetrical, one arm curved laterad, shorter than other, straight arm ( Fig. 54 ). Style with anterior medial arm perpendicular to base, apophysis with apex truncate, 3–4 ventroapical teeth ( Fig. 55 ). Plate with base triangular, medial margin straight, divergent, lateral margin sinuous apically, rounded basally; apex somewhat rectangular, sometimes lateral distal angle acute, usually right-angled, sometimes notched medially; 3–7 uniseriate, marginal macrosetae ( Fig. 56 ), sometimes one offset more medially; aedeagus in cleared specimen, when viewed as in Fig. 56 , with spine always on left side. Pygofer laterally, about rectangular, dorsal and ventrobasal margin parallel, ventrodistal margin angled dorsad, sinuous, medially with sclerotized lobe ( Fig. 58 ); dorsally, as in Fig. 57 . Pygofer lobe narrow, rounded, merged with dorsal margin of pygofer; apex extending well beyond posterior apex of plate ( Fig. 58 ).

Female. Dimensions. (n=21) Length from apex of vertex to apex of tegmina 2.1–2.4 mm, length from apex of vertex to apex of abdomen 2.7–3.1 mm, median length of vertex 0.4–0.5 mm, length of vertex next to eye 0.4–0.5 mm, length of pronotum 0.3 mm, width of head 0.8–0.9 mm, width of pronotum 0.7–0.8 mm, diameter of ocellus 26–30 µm, ocellocular distance 31–45 µm.

Genitalia. Sternite 7 with posterior margin with shallow, narrow notch ( Fig. 59 ).

Material examined. Holotype male. South Africa. Free State Province. Platberg, summit, Ladybrand, 29°11ʹS, 27°25ʹE, 1740 m, 5.iii.2002, M. Stiller, DVac, common grasses and sedges as follows: Andropogon schirensis ; Eragrostis capensis , E. curvula , E. sclerantha subsp. sclerantha , Heteropogon contortus (Poaceae) , Ficinia sp. (Cyperaceae) ( SANC). Paratypes. 79♂, 35♀. Eastern Cape Province. 1♂, 2♀, Aliwal North, 30°45ʹS, 26°45ʹE, 12.i.1986, J.G. Theron, sweeping; 4♂, 2♀, Rhodes, 30°48ʹS, 27°58ʹE, 23.iv.2000, M. Stiller, sweeping grass; 18♂, 5♀, Rhodes, 30°51ʹS, 27°54ʹE, 1965 m, 27.iv.2006, M. Stiller, DVac, roadside grass and forbs, Eragrostis sp. dominant. Free State Province. 1♂, Golden Gate, 28°31ʹS, 28°37ʹE, 6.i.1971, R. Kluge, sweeping; 1♂, Fouriesburg, 28°37ʹS, 28°13ʹE, 19.xii.1978, J.G. Theron, sweeping; 3♂, 2♀, Clocolan, 28°54ʹS, 27°32ʹE, 11.i.1986, J.G. Theron, sweeping; 8♂, 6♀, Zastron 1 km N, 30°15ʹS, 27°04ʹE, 1550 m, 5.iii.2002, M. Stiller, DVac, Themeda triandra dominant on dry embankment on road verge; 21♂, 9♀, ibid., holotype; 1♂, 3♀, Koloniesplaas, Memel, 27°42ʹS, 28°36ʹE, 1850 m, 14.xi.2003, M. Stiller, grazed pasture, sweeping, short, grazed grass (less than 5cm long); 2♂, Golden Gate, site #5, 28°31ʹS, 28°34ʹE, 1890 m, 23.x.2005, MDTP survey, blue and white pan trap. KwaZulu-Natal Province. 1♂, 2♀, Dundee, 28°10ʹS, 30°14ʹE, 21.i.1981, J.G. Theron, sweeping. Mpumalanga Province. 1♂, Ossewakop, Wakkerstroom, 27°23ʹS, 30°09ʹE, 2160 m, 7.iii.2002, M. Stiller, DVac; 12♂, Cedarmont road, 26°44ʹS, 29°03ʹE, 1550 m, 4.i.2004, M. Stiller, sweeping; 3♂, Belfast 1 km W, 25°41ʹS, 29°58ʹE, 1900 m, 17.ii.2005, M. Stiller, grass and forbs in grazed pasture, DVac. North-West Province. 2♂, 1♀, Vredefort Dome near Parys, 26°48ʹS, 27°22ʹE, 26.xii.2000, M. Stiller, grass and forbs, sweeping ( BMNH, INHS, SANC).

Remarks. The male of V. dentulicans can be recognized by the narrow rectangular plate apex ( Fig. 56 ) and the lateral, single, triangular spine on the aedeagal shaft ( Figs 52, 53 ). All other species of Vilargus have the plate rounded, truncate or triangular, except in V. lobulicans , where the process of the plate is also narrow, but distinctly rounded ( Fig. 64 ). Vilargus lobulicans is also the only species that does not have a distinct process on the shaft or preatrium, and is considered to have fused with the shaft, and therefore giving rise to the expanded, asymmetrical apex of the shaft. The pygofer lobe of V. dentulicans with its ventral, rounded sclerotized tooth is similar to that found in V. bicornicans , but the plate and aedeagus of this species and V. dentulicans differ significantly. The shape of the plate is however similar to Pravistylus trunculidiscus Stiller, 2010 , although the aedeagus does not correspond with that of this species, or for that matter with the genus. None of the 27 dissected males of V. dentulicans show obvious signs of parasitism by Dryinidae or Pipunculidae .

Figures

FIGURES 7–14. Vilargus species. Habitus. 7–9. V. dentulicans sp. n. male. 10–14. V. lobulicans sp. n. 10–11, male; 12– 13, female; 14, nymph. (scale = 1 mm).

FIGURES 52–59. Vilargus dentulicans sp. n. Male and female genitalia. 52, aedeagus, dorsally; 53, aedeagus, laterally; 54, connective; 55, style; 56, plate; 57, pygofer, dorsally; 58, pygofer, laterally; 59, female, sternite 7 (scale = 0.1 mm).

FIGURES 60–67. Vilargus lobulicans sp. n. Male and female genitalia. 60, aedeagus, dorsally; 61, aedeagus, laterally; 62, connective; 63, style; 64, plate; 65, pygofer, dorsally; 66, pygofer, laterally; 67, female, sternite 7 (scale = 0.1 mm).