Discolopeus arctus, 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 : 216-218

Discolopeus arctus sp.n.

Figs 7 a–k, 8a–h, 18c–e.

Diagnosis. Crown short; small amorphous markings on crown and pronotum. Subgenital plate obovate; ratio of length to width 1.15–1.34. Aedeagal shaft ventrally with subbasal short paired tooth, shaft distad of gonopore very narrow, right-angled, compressed, sclerotized; dorsal apodeme in dorsal view U-shaped with adpressed arms; aedeagal paraphysis thin, gracile, short, as long as shaft. Style apophysis compressed. Connective with transverse bar concave, arms short. Pygofer lobe bipinnate, apex with dorsal sclerotized, compressed process and ventral membranous lobe.

Etymology. Named in Latin with the verb for the narrowed, or compressed aedeagal shaft, arctus , compress, confine, contract, press together.

Male, female and nymph. Color. Ochraceous to stramineous, disc of crown with paired brown marking. Pronotum with few amorphous brown markings ( Figs 8 a–d). Face with clypeus with horizontal brown arcs ( Figs 8g, 8h ); crown with two brown markings ( Figs 8a, 8b ). Tegmina with discal and claval cells with brown marking. Nymph pale yellow, with brown banding in pronotum and adjoining distal part of thorax, basal abdominal segments 1–4 and penultimate abdominal segment ( Figs 8e, 8f ).

Male. Measurements. Overall length 4.12–4.30 mm; crown length 0.35–0.38 mm; crown length next to eye 0.35–0.38 mm; pronotum length 0.47–0.50 mm; head width 1.2 8– 1.35 mm; pronotum width 1.17–1.25 mm; ocellus diameter 34.3–44.7 µm; interocellar distance 39.5–51.5 µm.

Male. Genitalia. Tergite X elongate, parallel-sided in dorsal view ( Fig. 7a ). Anterior abdominal apodeme elongate, wide ( Figs 7a, 7b ). Pygofer lobe bilobate, ventrally with membranous lobe, dorsally with compressed, sclerotized process, process ventroapically with two small teeth; process in dorsal view curved lateroposteriad ( Fig. 7b ). Subgenital plate short, apex broadly rounded; lateral distal margin rounded, lateral proximal margin straight; macrosetae in rows near apex (up to seven macrosetae) and subapex (up to four macrosetae) ( Fig. 7c ), margin and submargin with fine setae. Ratio of length of subgenital plate medially/greatest width = 1.15–1.34 (n=9). Valve transversely triangular, base usually with membranous apodeme ( Fig. 7c ). Aedeagus with shaft compressed, sclerotized, shaft apex right-angled dorsally, base horizontal, dorsal apodeme right-angled dorsally; shaft ventrally on horizontal section with short, paired sclerotized tooth; gonopore elongate, posteriad to ventrad ( Figs 7d, 7e ). Aedeagal paraphysis narrow, tubular, apex acuminate, attaining apex of shaft ( Figs 7d, 7f ). Style with apophysis compressed, triangular in lateral view, digitate in dorsal view, preapical lobe acute, preapical angle concave; tooth ventrally ( Figs 7g, 7h ); style situated medially in subgenital plate ( Fig. 7c ). Connective medially slightly concave, arms acutely angled to mid-section ( Fig. 7i ).

Female. Measurements. Overall length 4.60–4.84 mm; crown length 0.38–0.42 mm; crown length next to eye 0.37–0.39 mm; pronotum length 0.51–0.54 mm; head width 1.3 3– 1.41 mm; pronotum width 1.25–1.36 mm; ocellus diameter 39.1–47.5 µm; interocellar distance 40.0–52.9 µm.

Female. Genitalia. Sternite VII posteromedially with deep, narrow U-shaped notch ( Fig. 7j ). Valvifer 1 elongate, about two times longer than wide, posterior margin with rounded basal emargination and square base ( Figs 7l, 7m ).

Material examined. Holotype male. Northern Cape Province. CCDL26249, Brakwater, Oorlogskloof, - 31.4656, 19.0799, 2016/12/17, M. Stiller, sweeping Diospyros austro-africana Ebenaceae . Paratypes. 54♂, 59♀, 27 nymphs. Northern Cape Province. 1♂, 4♀, CCDL26240, Nieuwoudtville, -31.3667, 19.1167, 1978/02/01, J.G. Theron, sweeping Diospyros austro-africana Ebenaceae ; 11♂, 9♀, 11 nymphs, CCDL18205, Biesiesfontein farm south Springbok, -29.75, 17.9333, 2002/09/29, M. Stiller, sweeping Diospyros ramulosa Ebenaceae ; 1♂, CCDL18206, Anenous Pass north Steinkopf, -29.21667, 17.616667, 2002/10/01, M. Stiller, sweeping Nylandtia spinosa Polygalaceae ; 19♂, 26♀, 7 nymphs, Ibid. holotype; 11♂, 10♀, 9 nymphs, CCDL26250, Swartkliphuis, Oorlogskloof, -31.5128, 19.1137, 2016/12/18, M. Stiller, sweeping Phylica oleaefolia Rhamnaceae . Western Cape Province. 9♂, 9♀, CCDL26238, Clanwilliam Dam, -30.2167, 18.9, 1976/12/26, J.G. Theron, sweeping Diospyros ramulosa Ebenaceae ; 2♂, 1♀, CCDL26239, Clanwilliam, -32.1667, 18.8833, 1978/10/08, J.G. Theron, sweeping Diospyros austro-africana Ebenaceae ; 1♂, 3♀, CCDL18834, Wiedouw farm base of Gifberg Pass, - 31.7334, 18.76661, 2002/10/03, M. Stiller, sweeping Phylica oleaefolia Rhamnaceae .

Remarks. This species and D. copeus and D. thigmacaenus have a short crown, elongate tegmina and well developed hind wing. The genitalia differ distinctly, with D. arctus having a large aedeagal shaft, with its apex compressed and sclerotized. This apex is prone to damage, as observed in five out of 13 dissected males, consisting of the dorsally curved apex of the shaft missing partially or entirely. In D. copeus the aedeagal shaft is narrow, tubular basally and depressed apically. The shaft of the aedeagus of D. thigmacaenus is tubular, straight with an adpressed paired tooth at its apex. The pygofer lobes differ distinctly: D. arctus has a dorsal compressed sclerotized lobe and ventral membranous lobe; D. copeus has two short triangular to rounded processes, one posteriad the other ventrad; D. thigmacaenus has a large ventrad acuminate process. The pygofer lobe of D. diacaenus , D. lissus and D. antizomavorus is unmodified. The style of this species is similar to that of D. lissus , but that species differs in other genital characters and habitus. Distribution map of two species of Diospyros ( Figs 18c, 18d ) and the potential natural distribution of D. arctus is in Fig. 18e . Few records in the SANC database imply that this species could be restricted to the western parts of South Africa. Other records of leafhoppers on Diospyros include Austroagallia, Capoideus , Citorus , Hadroca , Johanus , Renosteria and Stirellus . Trees or tall shrubs of Diospyros have been fogged on the High Veld and produced species of Empoasca, Penthimiola and Scaphoidophyes . In subtropical areas of the eastern parts of South Africa (i.e. KZN Province) Citorus, Hodoedocus, Mamates and Penthimia were found on Diospyros species.

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 8a–j. Discolopeus arctus n. gen. & sp., habitus. a, b. Male and female respectively, dorsally; c, d. Male and female respectively, laterally; e, f. Nymphs, early and late instar, dorsally; g, h. Face, male and female, respectively; i, hind wing; j, tegmina.

FIGURE 18a–f. Distribution maps of leafhopper species of Discolopeus gen.n. and associated plants. a. Galenia africana; b. D. diacaenus sp.n.; c. Diospyros austro-africana; d. Diospyros ramulosa; e. Potential natural distribution of D. arctus sp.n.; f. Antizoma miersiana in north western South Africa and southern Namibia.