Vilargus lobulicans, Stiller, 2010

Stiller, M., 2010, Revision of Vilargus Theron (Hemiptera: Cicadellidae: Deltocephalinae) from South Africa, Zootaxa 2674 (1), pp. 1-25 : 9-11

Vilargus lobulicans sp. n.

( Figs 10–14 , 60–67 ).

Diagnosis. Aedeagus without process, but apex expanded with small, lateral, asymmetric lobes. Plate triangular, with posterior medial margin narrowly digitate. Pygofer lobe acutely triangular.

Etymology. Latin, lobus, m. an elongated protuberance or projection, lobulicus, diminutive, for the shape of the subgenital plate that has the posterior margin produced into a blunt process.

Colour. Male, female and nymph. Ochraceous ( Figs 10, 12, 14 , specimens from Henderson Heights; Figs 11, 13 , specimens from Matatiele).

Male. Dimensions. (n=60) Length from apex of vertex to apex of tegmina 2.2–2.4 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 21–30 µm, ocellocular distance 36–46 µm.

Genitalia. Aedeagal shaft without basal or medial process; dorsally, apex of shaft bearing small, paired, lateral, asymmetric lobes, base of shaft parallel-sided, dorsal apodeme expanded posterolaterally ( Fig. 60 ); laterally, shaft slightly curving dorsally, tapering towards apex ( Fig. 61 ); gonopore apical, on one side of expanded apex ( Fig. 60 ). Connective symmetrical, stem slightly narrower than width across arms, stem and arms of similar width, stem about half as long as arms ( Fig. 62 ). Style with anterior medial arm short, not reaching beyond base of apophysis, acutely angled to base; apophysis elongate, apex acute, base parallelsided ( Fig. 63 ). Plate generally equidistantly triangular, medial margin straight, divergent; lateral margin subapically variably sinuous, sometimes straight, apex narrowed, digitate, about one third as long as length of plate, sometimes sclerotized; 3–6 uniseriate, medial macrosetae ( Fig. 64 ). Pygofer rectangular, ventroposterior margin rounded ( Fig. 66 ); dorsal view as in Fig. 65 . Pygofer lobe subapical, acutely triangular ( Fig. 66 ).

Female. Dimensions. (n=50) Length from apex of vertex to apex of tegmina 2.4–2.6 mm, length from apex of vertex to apex of abdomen 3.0– 3.2 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 0.8 mm, diameter of ocellus 25–29 µm, ocellocular distance 39–47 µm.

Genitalia. Sternite 7 posterior margin with rounded notch ( Fig. 67 ).

Material examined. Holotype male. South Africa. Eastern Cape Province. Vlakfontein Farm, south Queenstown , 31°57ʹS, 26°47ʹE, 1075 m, 19.iv.2006, M. Stiller, DVac, pasture grass ( SANC) . Paratypes. 57♂, 38♀, 9 nymphs. Eastern Cape Province . 3♂, 1♀, Queenstown , 31°54ʹS, 26°53ʹE, 20.i.1984, sweeping ; 1♂, Cathcart , 32°18ʹS, 27°12ʹE, 20.i.1984 ; 1♂, Lady Grey , 30°40ʹS, 27°15ʹE, 12.i.1986, sweeping; all J.G. Theron ; 16♂, 18♀, ibid., holotype ; 2♂, road between Molteno and Steynsburg , 31°15ʹS, 26°00ʹE, 1617 m, 20.iv.2006, DVac, Merxmuellera sp. dominant ; 3♂, 5♀, Doon Farm, Thomas River, Cathcart , 32°28ʹS, 27°17ʹE, 1115 m, 24.iv.2006, DVac, wet grass on rocky slope, leading to ridge covered with aloes ; 9♂, 6♀, 9 nymphs, Henderson Heights , NE Cathcart, 32°15ʹS, 27°11ʹE, 1270 m, 24.iv.2006, DVac, grazed pasture ; 18♂, 8♀, Matatiele , 30°25ʹS, 28°39ʹE, 1435 m, 30.iv.2006, DVac, grazed pasture. Northern Cape Province . 4♂, Warrenton , 10 km E, 28°10ʹS, 24°56ʹE, 1225 m, 3.viii.2005, DVac, grass and forbs; all collected by M. Stiller ( BMNH, INHS, SANC) .

Remarks. Vilargus lobulicans is known from widely separated localities in the Eastern and Northern Cape Provinces but probably also occurs elsewhere. The aedeagus of specimens from all these localities is remarkably uniform, whereas the shape of the plate is variable. Furthermore, the aedeagus of this species is the least characteristic of all the species of Vilargus as it does not have a lateral or ventral process ( Figs 60, 61 ). It is speculated that the characteristic shape of the male aedeagus of this species is the result of fusion of the process with the shaft, resulting in the relatively thick shaft and apical modifications. The species is placed in Vilargus due to the notched posterior margin of the female sternite 7. In terms of the aedeagus, it closely resembles a number of species of Pravistylus , such as P. mecophysis , P. bidentidiscus and P. caenophallus ( Stiller, 2010) . However, in general the sternite 7 of females of Pravistylus , is ligulate, or occasionally notched, but then flanked by paired, acute processes ( Stiller, 2010). Conversely species of Vilargus are characterized by having the female with the sternite 7 notched, e.g. V.bicornicans , Fig. 42 , V. dentulicans , Fig. 59 , V. lobulicans , Fig. 67 , V. pumilicans , Figs 76–79 , and V. trunculicans , Figs 111–115 . Two exceptions are V. budenticans , ( Figs 50, 51 , notch flanked with rounded process) and V. triquetricans ( Fig. 103 , ligulate). The males of these latter two species have the aedeagus with a basal paraphysis or an asymmetric process respectively. No parasitized or deformed specimens were found in the dissections of 23 males and 10 females.

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 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).

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 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 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 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 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).

FIGURES 92–103. Vilargus triquetricans sp. n. Male and female genitalia. 92, aedeagus, ventrally; 93, aedeagus, laterally; 94, connective; 95, style; 96, aedeagus, ventrally; 97, aedeagus, laterally; 98, aedeagus, laterally; 99, plate; 100, pygofer, dorsally; 101, pygofer, laterally; 103, pygofer, laterally; 103, female, sternite 7 (scale = 0.1 mm).