Vilargus pumilicans (Naudé)

Stiller, M., 2010, Revision of Vilargus Theron (Hemiptera: Cicadellidae: Deltocephalinae) from South Africa, Zootaxa 2674 (1), pp. 1-25 : 11-14

Vilargus pumilicans (Naudé)

( Figs 15–21 , 68–85 ).

Deltocephalus pumilicans Naudé, 1926: 49 .

Vilargus pumilicans (Naudé) ; Theron, 1975: 198.

Diagnosis. Aedeagal preatrium with single, elongate, posteriad paraphysis, about twice as long as shaft, paraphysis asymmetrical. Pygofer lobe triangular, subapical. Female sternite 7 with notch of variable depth and width.

Colour. Male and female. Vertex colouration variable, yellowish to ochraceous, sometimes with fuscous markings. About 7 horizontal arcs visible on clypeus. Usually brachypterous, with female occasionally macropterous or rarely males macropterous. Brachypters as in Figs 15, 17 , specimens from Steenkoolspruit; Figs 16, 18 , specimens from Volksrust. Macropters as in Figs 19, 20 , specimens from Steenkoolspruit; Fig. 21 , specimen from Volksrust.

Abdominal apodeme. Figs 75, 76 .

Male. Dimensions. (n=80) Length from apex of vertex to apex of tegmina 2.1–2.4 mm, length from apex of vertex to apex of abdomen 2.3–2.7 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 0.7–0.8 mm, width of pronotum 0.7 mm, diameter of ocellus 26–29 µm, ocellocular distance 33–46 µm.

Genitalia. Aedeagus, dorsally, with dorsal apodeme expanded laterad, about two times wider than width across paraphysis ( Fig. 68 ). Aedeagal shaft, laterally, arising dorsally from atrium, curved dorsally; preatrium expanded ventrad, sclerotized fusion with paraphysis ( Fig. 69 sf), paraphysis ( Fig. 69 p ) directed posteriad, dorsal part of aedeagus well separated from paraphysis; paraphysis mediolateral margin sometimes asymmetrically expanded dorsad; shaft about one third as long as length of paraphysis ( Fig. 69 ); gonopore apical, oblique. Connective with stem and arms of similar length, arms slightly asymmetric ( Fig. 70 ), articulating with aedeagus at fusion between paraphysis and expanded preatrium ( Fig. 69 c ). Style with apophysis variably positioned in plate:

a. Apophysis near base of plate ( Fig. 72 , specimen from Charlton Farm, Eastern Cape Province) and in specimens from other localities in Eastern Cape Province, Free State Province, Gauteng Province, KwaZulu-Natal Province, and Mpumalanga Province.

b. Apophysis near apex of plate ( Fig. 73 , specimen from De Hoop Nature Reserve, Western Cape Province).

Plate generally triangular; medial margin short, straight, divergent or parallel, posterior margin broadly rounded, lateral margin converging on medial margin, slightly rounded; 3–5 marginal macrosetae; median length from apex of valve to apex of plate slightly less than greatest median length of valve ( Figs 72, 73 ). Pygofer lobe subapical, triangular ( Fig. 74 ).

Female. Dimensions. Brachypter (n=73). Length from apex of vertex to apex of tegmina 2.3–2.5 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 26–29 µm, ocellocular distance 36–50 µm.

Macropter (n=6). Length from apex of vertex to apex of tegmina 2.9–3.2 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 0.2–0.3 mm, length of pronotum 0.3–0.4 mm, width of head 0.8–0.9 mm, width of pronotum 0.8 mm, diameter of ocellus 28 µm, ocellocular distance 34–45 µm.

Genitalia. Sternite 7 with posterior margin notched, of variable depth and width (narrow, shallow as in Figs 77 , specimen from Bergville; wide, shallow as in Fig. 78 , specimen from Cedarmont; deep as in Fig. 79 , specimen from Charlton Farm)

Valvula 3 with about 8 submarginal setae ( Figs 80, 81 ); valvula 2 uniformly pointed ( Fig. 82 ), finely denticulate ( Fig. 83 ); valvula 1 lanceolate ( Fig. 84 ), sculpture imbricate ( Fig. 85 ).

Type material examined. Holotype male. South Africa. Western Cape Province. Viljoen’s Pass , [c. 34°05ʹS, 19°04ʹE], 12.i.1923, F.W. Pettey ( SANC) . Paratypes. 3♂, ibid., holotype ( SANC) .

Additional material examined. 346♂, 251♀, 23 nymphs. Numerous localities in Lesotho and the following provinces in South Africa: Eastern Cape, Free State, Gauteng, KwaZulu-Natal, Limpopo, Northern Cape, North-West , Western Cape ( BMNH, INHS, SANC) .

Remarks. Naudé (1926) described this species from 5 males reportedly recorded from Viljoen’s Pass near Elgin in the Western Cape Province. The holotype and three paratypes have remained in the collection (SANC), and as these specimens were preserved in alcohol (according to Naudé) their colours are now almost completely faded. Theron (1975) reported that no specimens of V. pumilicans were found at the type locality and that it appeared that their distribution was probably highly sporadic. This trend is also evident in material acquired more recently, and that colouration is also variable.

Vilargus pumilicans is variable in the degree of asymmetry of the paraphysis of the aedeagus of the male. Furthermore, there appears to be a small but consistent difference between the male specimens from the Western Cape and those from other provinces. In the Western Cape the dorsal apophysis of the style is elongated and reaches the apex of the posterior margin of the plate, and in specimens from other provinces the style is shorter and well retracted into the plate. Throughout the distribution of V. pumilicans the posterior margin of the female sternite 7 is highly variable, with the notch as deep as wide, to very shallow and wide. For instance V. lobulicans ( Fig. 67 ), V. trunculicans ( Figs 111–115 ) and to a lesser extent V. dentulicans ( Fig. 59 ) have a similar notch to that of V. pumilicans ( Fig 77–79 ). Species recognition is therefore based on the male, and only when at least one species of Vilargus is found at a particular site, can the associated female sometimes be identified to species.

The aedeagus of V. pumilicans is similar to that of V. budenticans with differences in the shape of the plate, pygofer and female sternite 7 as discussed under the remarks of the latter. The plate of V. pumilicans and V. bicornicans are similar, with distinct difference found in the aedeagus, pygofer, pygofer lobe and female sternite 7, as discussed under the remarks of the latter.

Parasitized specimens are rare. Out of 60 dissected males, four were parasitized and three had the paraphysis broken. Three of the four parasitized specimens have a Y-shaped connective, and one has a deformed plate but normal connective.

Figures

FIGURES 15–21. Vilargus pumilicans sp. n. Habitus. 15–16, 19, male; 17–18, female; 20–21, female (scale = 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 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 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 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).