Vilargus bicornicans, Stiller, 2010

Stiller, M., 2010, Revision of Vilargus Theron (Hemiptera: Cicadellidae: Deltocephalinae) from South Africa, Zootaxa 2674 (1), pp. 1-25 : 5

Vilargus bicornicans sp. n.

( Figs 1–3 , 35–42 ).

Diagnosis. Aedeagus dorsally with transverse, ovoid dorsal apodeme, laterally with tapered process arising lateroventrally from basal part of shaft, and curved dorsad, shaft and process of similar length. Plate medial margin straight, posterior margin broadly rounded, lateral margin rounded, sometimes slightly sinuous. Pygofer and pygofer lobe extending well beyond apex of plate; posteromedial margin below pygofer lobe with medially curved sclerotized lobe. Female with sternite 7 posterior margin with narrow, parallel-sided notch.

Etymology. Latin, bi, two, cornus, horn, referring to the aedeagus appearing to have two horn-like structures.

Colour. Male, female and nymph. Ochraceous ( Figs 1–3 , specimens from Dordrecht, Eastern Cape Province).

Male. Dimensions. (n=65) Length from apex of vertex to apex of tegmina 2.2–2.3 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 27–30 µm, ocellocular distance 28–41 µm.

Genitalia. Aedeagus, dorsally, dorsal apodeme transverse, reniform; shaft tapered, with ventrolateral, tapered process ( Fig. 35 ); laterally, process basally widely merged with shaft, tapering towards apex; shaft tubular, both curved dorsad, of similar length; gonopore dorsal, apical ( Fig. 36 ). Connective symmetrical, stem slightly wider than width across arms ( Fig. 37 ). Style with anterior medial arm short, not extending beyond base of apophysis, acutely angled to base; apophysis elongate, apex truncate, with teeth ventrally on posterior margin, fine serration ventromedially ( Fig. 38 ). Plate in general roundly triangular; medial margin straight, posterior margin broadly rounded, lateral margin rounded, sometimes slightly sinuous ( Fig. 39 ); 2–5 marginal macrosetae. Pygofer, laterally, dorsal and basal ventral margins parallel, distal ventral margin angled dorsad, medially with sclerotized, rounded protrusion ( Fig. 41 ); dorsally as in Fig. 40 . Pygofer lobe short, rounded ( Fig. 41 ); extending well beyond apex of plate.

Female. Dimensions. (n=36) Length from apex of vertex to apex of tegmina 2.3–2.5 mm, length from apex of vertex to apex of abdomen 3.0– 3.4 mm, median length of vertex 0.5 mm, length of vertex next to eye 0.3 mm, length of pronotum 0.3 mm, width of head 0.9 mm, width of pronotum 0.7–0.9 mm, diameter of ocellus 26–31 µm, ocellocular distance 35–47 µm.

Genitalia. Sternite 7 posteriorly with narrow, deep notch, narrower, and deeper than in any other species ( Fig. 42 ).

Material examined. Holotype male. South Africa. Eastern Cape Province. Dordrecht , 31°32ʹS, 26°57ʹE, 1436 m, 26.iv.2006, M. Stiller, DVac, short grazed grass and forbs in road reserve ( SANC) . Paratypes. 68♂, 41♀, 4 nymphs. Eastern Cape Province . 1♂, 3♀, Cathcart , 32°18ʹS, 27°12ʹE, 20.i.1984, J.G. Theron, sweeping ; 1♂, Ongeluksnek , site #44, 30°20ʹS, 28°21ʹE, 1740 m, 5.xii.2005, MDTP survey, sweeping ; 1♂, Ongeluksnek , site #39, 30°20ʹS, 28°19ʹE, 1824 m, 8.xii.2005, MDTP survey, sweeping ; 1♂, Prentjiesberg , 31°07ʹS, 28°10ʹE, 1428 m, 11.xii.2005, MDTP survey, sweeping ; 7♂, 3♀, Penhoek, between Aliwal North and Queenstown , 31°26ʹS, 26°41ʹE, 1854 m, 19.iv.2006, DVac, grazed pasture ; 13♂, 5♀, 1 nymph, Charlton Farm , N Somerset East, 32°40ʹS, 25°40ʹE, 1271 m, 23.iv.2006, DVac, pasture with tufted, ungrazed (unpalatable) grass ; 23♂, 17♀, Doon Farm, Thomas River, Cathcart , 32°28ʹS, 27°17ʹE, 1115 m, 24.iv.2006, DVac, grass on rocky outcrop covered with aloes ; 19♂, 12♀, 3 nymphs, ibid., holotype ; 1♂, between Dordrecht and Rossouw , 31°48ʹS, 26°06ʹE, 1767 m, 26.iv.2006, DVac, road reserve ; 2♂, 1♀, Groendal, Dordrecht , 31°09ʹS, 27°06ʹE, 1804 m, 26.iv.2006, DVac, road reserve; all collected by M. Stiller ( BMNH, INHS, SANC) .

Remarks. The plate of V. bicornicans ( Fig. 39 ) resembles that of V. pumilicans ( Figs 72, 73 ) and to a lesser extent with that of V. budenticans ( Fig. 47 ). However, there are marked differences in the aedeagal configuration of these three species. Vilargus pumilicans has an elongate ventral paraphysis and short aedeagal shaft ( Figs 68, 69 ), V. budenticans has a short ventral paraphysis and long aedeagal shaft ( Figs 43, 44 ) and V. bicornicans has a dorsally curved shaft and ventrolateral tapering process arising from the base of the shaft ( Figs 35, 36 ). The female sternite 7 of V. bicornicans has a notch that is narrower, parallel-sided and deeper ( Fig. 42 ) than that of any other species of Vilargus . None of the dissections of 13 males and 5 females shows deformities.

Figures

FIGURES 1–6. Vilargus species. Habitus. 1–3, V. bicornicans sp. n. 1, male; 2, female; 3, nymph. 4–6, V. budenticans sp. n. 4–5, male; 6, female (scale = 1 mm).

FIGURES 35–42. Vilargus bicornicans sp. n. Male and female genitalia. 35, aedeagus, dorsally; 36, aedeagus, laterally; 37, connective; 38, style; 39, plate; 40, pygofer, dorsally; 41, pygofer, laterally; 42, female, sternite 7 (scale = 0.1 mm).

FIGURES 68–85. Vilargus pumilicans sp. n. Male and female genitalia. 68, aedeagus, dorsally; 69, aedeagus, laterally, sf = sclerotized fusion, c = connective, p = paraphysis;; 70, connective; 71, style; 72, plate; 73, plate; 74, pygofer, laterally; 75, anterior abdominal apodeme; 76, posterior abdominal apodeme; 77–85, female. 77–79, sternite 80, valvula 3; 81, valvula 3, ultrastructure; 82, valvula 2; 83, valvula 2, ultrastructure; 85, valvula 1, ultrastructure (scale = 0.1 mm).

FIGURES 43–51. Vilargus budenticans sp. n. Male and female genitalia. 43, aedeagus, dorsally; 44, aedeagus, laterally, mf = membranous fusion, fc = fused connective, p = paraphysis; 45, connective; 46, style; 47, plate; 48, pygofer, dorsally; 49, pygofer, laterally; 50, female, sternite 7; 51, female, sternite 7 (scale = 0.1 mm).