Drabescus nigrofacialis (Distant)

Viraktamath, C. A., Webb, M. D. & Yeshwanth, H. M., 2022, Review of the leafhopper genus Drabescus Stål (Hemiptera: Cicadellidae: Deltocephalinae) in the Indian subcontinent with description of one new species, Zootaxa 5128 (2), pp. 225-247 : 238-239

Drabescus nigrofacialis (Distant)

Figs 2 CD, K, 3H, 5F, 11A–E.

Kutara nigrofacialis Distant 1918: 42–43 .

Drabescus nigrofacialis (Distant) : Zhang & Webb 1996: 25, figs 327–332, 524.

Creamy white with rich and bold dark brown maculation on crown, pronotum and exposed mesonotum. Fore margin of head with transverse white band extending laterally onto greyish brown eyes. Face largely black, with areas on either side of frontal suture below eyes reddish dark brown. Antennae with flagellum ochraceous. Pronotum with median longitudinal stripe extending entire length, dark brown to black. Exposed mesonotum with basal triangles poorly developed, median area little darker with fewer white spots. Forewing hyaline with brownish tinge heavily spotted with dark brown except median transverse area, appendix dark brown, areas surrounding veins of apical cells dark brown; veins dark brown spotted with white. Thoracic pleurites and sternites dark brown.

Crown produced and triangular, medially longer than next to eyes, more or less flat, about 3× as wide between eyes as long medially, transition to face acutely angular, fore margin rimmed. Face with lateral frontal suture convex ventrad of antennal bases, distance between bases of antennae about 2.4× as wide as width of clypeus at apex; clypellus widened distally. Pronotum about 2.4× as wide as long medially, posterior margin concave. Exposed mesonotum longer than pronotum. Forewing claval veins connected by a cross vein. Fore tibia expanded.

Male genitalia. Pygofer broad basally and narrowed posteriorly, about 1.3× as long as height at base in lateral view, dorsal margin concave, dorsoposterior angle conically rounded with a spine-like process, sinuately curved and exceeding apex of pygofer. Valve with posterior margin medially emarginated, about 3.3× as wide as long medially. Subgenital plate elongate about 2.6× as long as wide at base, distal area narrowed into less sclerotized appendage. Style without subapical lobe, linear, apophysis widened before apex and narrowed apically, transversely striate. Connective with stem as long as arms. Aedeagus with dorsal apodeme well-developed, about half as long shaft; aedeagal shaft without basal processes, with lateral lamellate expansion in distal 0.33, gonopore subapical on ventral surface.

Female pregenital segment. Sternite VII 2.8× as wide as long, posterior margin produced medially with a median V-shaped excavation.

Measurements. Male 6.6 –8.1 mm long, 2.6–3.0 mm wide across eyes and 2.2–2.6 mm wide across posterolateral angles of pronotum. Female 8.2–8.4 mm long, 3.1–3.0 mm wide across eyes and 2.6–2.7 mm wide across posterolateral angles of pronotum.

Material examined. INDIA: Karnataka: LECTOTYPE ♂ “Chikkaballapura, T.V. Campbell ” ( BMNH); Andhra Pradesh: 1♂, Araku Valley :: 21.ix.2013, Vinayaka,T; 1♂, Nizamabad, Rudrur, 13.ix.2012, Reddy, A.N.; Karnataka: 1♂, Kemmangundi, 11.iv.1975, Viraktamath, C.A.; 1♀, Bangalore, 11.vii.1977, Shivashankar N.P.; 1♀, Mudigere, 7.iv.1975, Viraktamath, C.A.; 1♂, Hunsur, 18.1.1978, Viraktamath, C.A.; 1♀, Gulbarga, 9.ix. 1984, Shashidhar; 1♂, 1♀, Kodayamale, 28.xi.1984, Shashidhar; 1♂, Belgaum, Joida, 15.V.2012, A.R.V. Kumar; 1♀, Shimogga, Navile, 17.i.2011, Reddy, A.N.; 1♀ Chikballapura, Nandi hills, 7.vi.2011 Yeshwanth, H.M.; 1♀, Bangalore, Hessaraghatta, 13.xi.2015, Yeshwanth, H.M.; Tamil Nadu: 1♂, Burliar, 1♂, 5.vi.1977, Viraktamath, C.A.; 1♀, Yercaud, 20.ix.1978, Viraktamath, C.A. ( UASB); Meghalaya: 1♂, Ri-Bhoi, ICAR -RCNEH, Umiam, 10.vi.2013, Yeshwanth, H.M. ( UASB).

Remarks. This species was described from an unknown number of specimens (syntype (s)) with the following data: “South India: Chikkaballapura (T.V. Campbell)“. The extant type was examined by Zhang & Webb 1996: 25 and designated as lectotype. Among the species of Drabescus without basal processes on the aedeagal shaft, this species can easily be recognised by the short aedeagal shaft with apical half expanded laterally and the style without subapical lobe. The female can be recognised by the sternite VII with a median V-shaped excavation on the posterior margin. This species occurs in southern states of peninsular India (Andhra Pradesh, Karnataka, Tamil Nadu) and in northeast India (Meghalaya).

Figures

FIGURES 2 A–L. Species of Drabescus from Indian subcontinent. Habitus, dorsal and lateral views (A–F) and female sternite VII (G–L). A–B, D. nervosopunctatus Signoret; C–D, D. nigrofacialis (Distant); E–F, D. shillongensis Rao; G, D. angulatus Signoret; H, D. kempi Pruthi; I, D. limbaticeps Signoret; J, D. nervosopunctatus Signoret; K, D. nigrofacialis (Distant); L, D. shillongensis Rao.