Discolopeus thigmacaenus, Stiller, 2019

Stiller, Michael, 2019, A new leafhopper genus Discolopeus and nine new species (Hemiptera, Cicadellidae, Deltocephalinae) associated with shrubs, trees and poisonous plants in South Africa, Zootaxa 4559 (2), pp. 201-244 : 221-223

Discolopeus thigmacaenus sp.n.

Fig. 11 a–h, 12a–d, 19c.

Diagnosis. Crown short; two pairs of small wedge-shaped dark brown markings apically and subapically. Subgenital plate obovate; ratio of length to width 1.22–1.37. Aedeagal shaft apex with one pair of acute teeth, adpressed to shaft, directed ventrad; shaft uniformly curved posterodorsally, tubular, sclerotized; dorsal apodeme in dorsal view elongate, T-shaped, slightly shorter than shaft; aedeagal process right-angled at base, smooth, longer than aedeagal shaft. Style apophysis elongate, digitate. Connective with transverse bar straight, arms long. Pygofer lobe with large, ventroapical, sclerotized acuminate process. Tergite X rectangular; ventroapically with paired, bipinnate tooth.

Etymology. Named for the adpressed teeth or teeth touching, in contact with the shaft, verb and noun in apposition in Greek, thigma, touch, and akaina, tooth.

Male, female and nymph. Color. Crown short, with two pairs of small wedge-shaped dark brown marking apically and subapically respectively, transverse faint orange line medially ( Figs 12 a–d). Pronotum with two pairs of brown to dark brown spots near compound eye ( Figs 12 a–d). Tegmina with many dark brown reticulate colour patterns and some recurved vein-like markings in costal cells ( Figs 12 a–d). Nymph stramineous, with two basal abdominal segments brown ( Fig. 12e ).

Male. Measurements. Overall length 4.40–4.65 mm; crown length 0.37–0.41 mm; crown length next to eye 0.36–0.39 mm; pronotum length 0.52–0.55 mm; head width 1.4 4– 1.50 mm; pronotum width 1.27–1.39 mm; ocellus diameter 35.2–44.6 µm; interocellar distance 57.2–71.6 µm.

Male. Genitalia. Tergite X elongate, rectangular in dorsal view ( Fig. 11a ), expanded ventrad in lateral view, distal ventral margin with elongated, acutely triangular, paired tooth-like process, tooth medial subbasal margin with small medial tooth ( Fig. 11b ). Pygofer with wide anterior apodeme; pygofer lobe with elongate ventroapical sclerotized process; about 14 macrosetae dorsomedially ( Figs 11a, 11b ). Subgenital plate length to width ratio 1.22–1.37 (n=5); laterobasal margin concave; apex broadly rounded; macrosetae in 2–3 irregular rows near apex ( Fig. 11c ). Valve transversely triangular, without anterior apodeme ( Fig. 11c ). Aedeagus with shaft elongate, sclerotized, straight in dorsal view, slightly curved in lateral view, apex with paired, acutely triangular tooth, directed ventrad, adpressed to shaft; gonopore apical ( Figs 11d, 11e ). Aedeagal paraphysis gracile, tubular, rightangled at base, apex acute, extending beyond apex of shaft ( Fig. 11d ). Style apophysis curvate, acuminate, elongated, curved dorsolaterally; preapical angle right-angled ( Fig. 11f ); positioned medially in subgenital plate ( Fig. 11c ). Connective with arms and stem of similar length ( Fig. 11g ).

Female. Measurements. Overall length 4.67–4.98 mm; crown length 0.40–0.42 mm; crown length next to eye 0.37–0.40 mm; pronotum length 0.53–0.57 mm; head width 1.5 1–1.58 mm; pronotum width 1.17–1.23 mm; ocellus diameter 41.5–55.0 µm; interocellar distance 64.0–81.4 µm.

Female. Genitalia. Sternite VII posterior margin with wide, shallow, sinuous notch, medially with narrow, shallow V-shaped subnotch ( Fig. 11h ). Valvifer 1 elongate, at least three times longer than wide (as in Figs 7k, 7l ), posterior margin narrowly rounded, anterior margin narrow, membranously fused to other valvifer 1. Valvula 3 with 2–3 rows of macrosetae.

Material examined. Holotype male. Western Cape Province. CCDL18235, Wiedouw farm base of Gifberg Pass, -31.73343, 18.76661, 2002/10/03, M. Stiller, sweeping Zygophyllum morgsana Zygophyllaceae . Paratypes. 6♂, 14♀, 6 nymphs. Northern Cape Province. 2♂, CCDL26246, Nieuwoudtville, -31.3667, 19.1333, 1978/02/01, Theron, J.G., sweeping; 5♀, CCDL26247, Nieuwoudtville 20km north, -31.2333, 19.35, 2002/10/07, M. Stiller, sweeping, Zygophyllum foetidum Zygophyllaceae ; 4♂, 9♀, 6 nymphs, Ibid. holotype.

Remarks. Discolopeus thigmacaenus has distinct features such as the adpressed apical teeth on the aedeagal shaft, right-angled aedeagal paraphysis, T-shaped dorsal apodeme, large acuminate, ventral pygofer lobe and bidentate spine on the ventral apex of abdominal tergite X. The subgenital plate has the basal lateral margin concave, in contrast to the straight margin of all other known species of Discolopeus . Colour patterns and shape of the crown resemble those of D. arctus , D. copeus and D. viraktamathi . Genitalia between these three species differ distinctly. The pygofer lobe in D. arctus has two parts, a membranous ventral lobe and a sclerotized, compressed, dorsal lobe, curvate laterally and minutely toothed ventrally. The aedeagus in D. arctus has an enlarged, compressed shaft with paired ventral teeth. The pygofer lobe in D. copeus is simple, with a short ventral and short medial sclerotized blunt tooth. The aedeagus in D. copeus has the apex chisel-shaped. The pygofer lobe in D. viraktamathi is lobulate and weakly sclerotized. Discolopeus copeus is the only species with a depressed apophysis of the style. Discolopeus arctus has the style apophysis compressed, as is the case in D. lissus . The point distribution map of D. thigmacaenus is in Fig. 19c. A number of species of leafhoppers in the genera Austroagallia , Bloemia , Bonaspeia, Chlorita, Circulifer, Coloborrhis, Equeefa , Hadroca , Johanus and Tzitzikamaia have been collected on Zygophyllum and other members of Zygophyllaceae (SANC leafhopper database, M. Stiller, personal observation).

Figures

FIGURE 7a–m. Discolopeus arctus n. gen. & sp., male and female genitalia, line drawing. a. Genital capsule, dorsally; b. Genital capsule, laterally; c. Subgenital plate, ventrally; d, e, f. Aedeagus, laterally, dorsally and ventrally respectively; g, h. Style, dorsally and laterally respectively; i. Connective, dorsally; j. Sternite VII; k, l. Valvifers 1, laterally, Clanwilliam and Nieuwoudtville respectively; m, profemur chaetotaxy.

FIGURE 11a–h. Discolopeus thigmacaenus n.gen. & sp., male and female genitalia, line drawing. a. Genital capsule, dorsally; b. Genital capsule, laterally; c. Subgenital plate, ventrally; d, e. Aedeagus, laterally and dorsally respectively; f. Style, dorsally; g. Connective; h. Sternite VII.

FIGURE 12a–i. Discolopeus thigmacaenus n.gen. & sp., habitus, dorsally. a. Wiedouw, male; b. Gifberg, female; c. Wiedouw, female; d. Gifberg, male; e. Nymph, Gifberg; f, hind wing, male; g, tegmina, male; h, hind wing female; i, tegmina, female.

FIGURE 19a–c. Distribution maps of leafhopper species of Discolopeus gen.n. and associated plants. a. Hyaenanche globosa near Vanrhynsdorp and one record near Citrusdal (red squares); b. Potential natural distribution of D. copeus sp.n. in the southwestern parts of South Africa, Western Cape Province; c. Point distributions of D. colopeus sp.n., D. lissus sp.n., D. tetracaenus sp.n., D. thigmacaenus sp.n., D. triacaenus sp.n. and D. viraktamathi sp.n. in Western, Northern and Eastern Cape Provinces.