Pravistylus mollidiscus Stiller 2010, sp. n.

(Figs 1 u; 2 z; 3 g; 4 g; 5 g; 6 f; 7 aw; 8 aj & ak)

Diagnosis. Plate uniformly triangular, apex wide, membranous (Fig. 2 z). Margin of plate apex difficult to distinguish at low magnification. Aedeagal shaft short, slightly depressed, almost straight, gonopore apical (Figs 3 g, 4 g). Style with distal part close to base (Fig. 5 g).

Etymology. Latin, plate, (discus) with membranous (mollis) apex.

Male and female. Pale ochraceous (all specimens collected in 70% alcohol). Tegmina with costal cells pale yellow; apical cells reduced. Hind wing less than half as long as tegmina (Figs 8 aj & ak).

Male. Dimensions. (n = 43) Length: apex of vertex to apex of tegmina 1.8–2.0 mm; apex of vertex to apex of abdomen 2.6–2.9 mm; vertex medially 0.4 mm; vertex next to eye 0.3 mm; pronotum medially 0.3 mm. Width: head 0.7–0.8 mm; pronotum 0.7 mm. Ocellar diameter 20.9–29.6 µm; ocellocular distance 39.0– 48.9 µm.

Genital capsule. Pygofer in lateral view with posterior ventral and dorsal margin uniformly lobate (Fig. 1 u). Pygofer lobe short, rounded, about as wide as pygofer (Fig. 1 u). Plate triangular, lateral margins slightly concave, apex wide, broadly rounded; apex always membranous; 5–8 macrosetae; plate 1.4–1.5 times as long as wide (Fig. 2 z). Aedeagal shaft in lateral view almost straight, robust, slightly depressed, slightly longer than length of dorsal apodeme; shaft arising ventrally from atrium; gonopore ventral, apical (Figs 3 g, 4 g). Style distal part close to anterior medial lobe; apex tapering acutely (Fig. 5 g). Connective, in lateral view, straight, with stem triangular, base narrower, width across arms almost as wide as stem (Fig. 6 f).

Female. Dimensions. (n = 33) Length: apex of vertex to apex of tegmina 1.9–2.0 mm; apex of vertex to apex of abdomen 3.0– 3.2 mm; vertex medially 0.4–0.5 mm; vertex next to eye 0.3 mm; pronotum medially 0.3 mm. Width: head 0.8–0.9 mm; pronotum 0.7–0.8 mm. Ocellar diameter 24.4.–29.5 µm; ocellocular distance 42.1–56.3 µm.

Genitalia. Sternite 7 ligula short, triangular (about half a long as medial length at base); notch stepped, deepest part rounded. Ligula sometimes with round, sclerotized area (Fig. 7 aw).

Material examined. Holotype male. South Africa, Eastern Cape. Zwelitcha near Tsolo, 31°10ʹS, 28°34ʹE, 1335 m, 29.iv.2006, M. Stiller, DVac, grazed veld (SANC). Paratypes. 48♂, 33♀. Eastern Cape. 10♂, 4♀, near Grahamstown and Alicedale road junction, 33°24ʹS, 26°22ʹE, 560 m, 23.iv.2006, grazed pasture and road reserve; 2♂, Olifantskop Pass, between Patterson and Cookhouse, 33°18ʹS, 25°57ʹE, 713 m, 23.iv.2006, disturbed grassland; 7♂, 3♀, Doon Farm, Thomas River, Cathcart, 32°28ʹS, 27°17ʹE, 1115 m, 24.iv.2006, wet grass on rocky ridge with Aloes; 20♂, 15♀, same data as holotype; 10♂, 11♀, Matatiele, 30°25ʹS, 28°39ʹE, 1435 m, 30.iv.2006, grazed grassland; all M. Stiller; all collected with DVac (BMNH, INHS, SANC).

Remarks. Pravistylus mollidiscus has a unique plate and aedeagus. The plate is basically triangular with a wide and weakly sclerotized apex (Fig. 2 z). The aedeagus is very short and thick and only slightly curved (Figs 3 g, 4 g). This species is most similar to P. deltoplacus with regard to the shape of the plate (Fig. 2 aa). In both species the plate is triangular. The relative width of the plate in P. mollidiscus is difficult to distinguish in situ because the apical margins are membranous. Pravistylus deltoplacus has the plate apex at least half as wide as that of P. mollidiscus, and that is distinctly sclerotized, and both have a similar length to width ratio. In P. mollidiscus the plate is 1.4–1.5 times as long as wide, and in P. deltoplacus it is 1.4–1.6 times as long as wide. Other species with triangular plates always have the lateral margin sinuous and often with tufts of fine setae, such as P. caenophallus (Fig. 2 y), P. odontopygeus sp. n. (Fig. 2 x) and P. pelorophallus sp. n. (Fig. 2 u). The aedeagus of P. deltoplacus (Fig. 3 c) in lateral view has a U-shaped shaft with a wide base and short up-turned apex. In the dorsal view the shaft is depressed, about half as thick and much longer (Fig. 4 c) than that of P. mollidiscus (Fig. 4 g). No other species has a similarly simplified aedeagus.