Vilargus trunculicans, Stiller, 2010

Stiller, M., 2010, Revision of Vilargus Theron (Hemiptera: Cicadellidae: Deltocephalinae) from South Africa, Zootaxa 2674 (1), pp. 1-25 : 20-25

Vilargus trunculicans sp. n.

( Figs 28–34 , 104–115 ).

Diagnosis. Male with aedeagus in dorsal view with shaft off-set from midline, opposite side of shaft with parallel-sided process, reaching beyond apex of shaft, and apex of process expanded. Plate rectangular.

Etymology. Latin, truncus, maimed, cut off, for the truncated posterior margin of the subgenital plate.

Colour. Male and female. Ochraceous ( Figs 28–30 , brachypter, specimens from Longtom Rail Siding, Qachasnek and Steenkoolspruit respectively. Figs 31–32, 34 , brachypter, specimens from Qachasnek and Steenkoolspruit; Fig. 33 , macropter, specimen from Steenkoolspruit).

Male. Dimensions. (n=77) Length from apex of vertex to apex of tegmina 2.0–2.3, length from apex of vertex to apex of abdomen 2.3–2.6, 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 mm, diameter of ocellus 24–30 µm, ocellocular distance 37–46 µm.

Genitalia. Aedeagal shaft, laterally, C-shaped, gradually curved dorsally ( Fig. 105 ); dorsally, shaft arising laterad of midline, process on opposite side, longer than shaft, apex with acute points; gonopore subapical, ventral ( Fig. 104 ). Connective with arms asymmetric, one arm shorter, more curved and angled laterad of other, more straightened arm ( Fig. 106 ); stem triangular, usually membranous. Style with anterior medial arm short, not reaching beyond base of apophysis, acutely angled to base; apophysis digitate, teeth ventrally, apex pointed ( Fig. 107 ). Plate short, rectangular; medial margin slightly divergent, posterior and lateral margins right-angled, posterior margin truncate; 2–5 macrosetae ( Fig. 108 ); aedeagus in cleared pygofer, viewed as in Fig. 108 , with process on always on right side. Pygofer rectangular, ventroposterior margin rounded. Pygofer lobe with acutely triangular, with narrow base ( Fig. 110 ); dorsal view ( Fig. 109 ).

Female. Dimensions. (n=118) Length from apex of vertex to apex of tegmina 2.1–2.3 mm, length from apex of vertex to apex of abdomen 2.7–3.0 mm, median length of vertex 0.4–0.5 mm, length of vertex next to eye 0.3 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 28 µm, ocellocular distance 31–49 µm.

Genitalia. Sternite 7 with posterior margin variable, shallow notch widely rounded or narrowly V-shaped ( Fig. 111 , specimen from Belfast; Figs 112, 113 , specimens from Ossewakop; Figs 114, 115 , specimens from Volksrust).

Material examined. Holotype male. South Africa. Mpumalanga Province. Steenkoolspruit Farm, Diepspruit near Kriel , 26°09ʹS, 29°15ʹE, 20.xii.2006, M. Stiller ( SANC) . Paratypes. 53♂, 27♀, 1 nymph. Free State Province . 1♂, Reitz, 22°25ʹS, 30°16ʹE, 22.i.1975, J.G. Theron; 1♂, Warden, 27°56ʹS, 29°00ʹE, 30.i.1981, J.G. Theron; 3♂, Koloniesplaas, Memel, 27°42ʹS, 28°36ʹE, 1850 m, 14.xi.2003, M. Stiller, sweeping short grazed grass (less than 5cm in length). KwaZulu-Natal Province . 1♂, Van Reenen, 28°22ʹS,

29°24ʹE, 19.xii.1978, J.G. Theron; 3♂, Groenvlei, 16.5 km SE Wakkerstroom , 27°29ʹS, 30°14ʹE, 1907 m, 2.ii.2007, DVac, grass and forbs on road verge. Mpumalanga Province. 1♂, 1♀, Suikerboschfontein Farm , 25°56ʹS, 30°19ʹE, 1700 m, 3.ii.2001, sweeping, grass and forbs; 11♂, 6♀, Ossewakop, Wakkerstroom , 27°23ʹS, 30°09ʹE, 2160 m, 7.iii.2002, DVac, tall grass in deep soil, and shorter, sparse grass on rocky outcrop; 6♂, 8♀, Volksrust, 5 km W route R543, 27°20ʹS, 29°50ʹE, 1700 m, 9.x.2004, sweeping, dry grazed grass; 2♂, 2♀, Belfast, 1 km W , 25°41ʹS, 29°58ʹE, 1900 m, 17.ii.2005, DVac, grass and forbs, grazed pasture; 3♂, 1♀, Longtom rail siding, 25°32ʹS, 30°03ʹE, 1957 m, 16.xi.2005, DVac, moribund grassland with Themeda triandra common; 21♂, 9♀, 1 nymph, ibid., holotype; all collected by M. Stiller ( BMNH, INHS, SANC) .

Remarks. Vilargus trunculicans and V. simulans have similar plates ( Figs 108 , 90 , respectively), but the structure of the aedeagus is distinctly different ( Figs 104 , 86 , respectively). In V. trunculicans the shaft is offset from the midline, with a long, curved process arsing from the opposite side of the preatrium ( Fig. 104 ). The shaft of the aedeagus in V. simulans arises from the midline with a short, straight spine-like process arising lateromedially and subbasally from the shaft ( Fig. 86 ).

One parasitized specimen has the connective symmetrical, Y-shaped with arms widely separated and a short stem. The style of this specimen is deformed, with the apophysis without teeth, directed posteriad and its anterior medial and lateral arms reduced. The aedeagus is also more compact, with the shaft and process shortened. The plate of this specimen has no macrosetae, but of similar shape to the other specimens. This is the only deformed specimen out of 16 dissected specimens.

Figures

FIGURES 28–34. Vilargus trunculicans sp. n. Habitus. 28–30, male; 31–34, female (scale = 1 mm).

FIGURES 104–115. Vilargus trunculicans sp. n. Male and female genitalia. 104, aedeagus, ventrally; 105, aedeagus, laterally; 106, connective; 107, style; 108, plate; 109, pygofer, dorsally; 110, pygofer, laterally; 111–115, female, sternite 7 (scale = 0.1 mm).

FIGURES 86–91. Vilargus simulans sp. n. Male genitalia. 86, aedeagus, ventrally; 87, aedeagus, laterally; 88, connective; 89, style; 90, plate; 91, pygofer, laterally (scale = 0.1 mm).