Discolopeus Stiller 2019, gen. n.
Creators: name: Stiller, Michael
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Cicadellidae
Discolopeus

description: Discolopeus gen. n.
Type species Discolopeus diacaenus sp.n. by original designation
Diagnosis. Aedeagus with paired elongate basal processes; subgenital plate with multiple rows of macrosetae; connective transverse, without stem; pygofer lobe narrow, digitate or modified with dorsal compressed sclerotized process and ventral membranous lobe or with short bifurcate sclerotized processes; macropterous or submacropterous in male and female; crown anterior margin acute.
Etymology. The genus name is a combination of Greek words describing the paired aedeagal processes. Two, di-, and for anything pointed, skolos, and referring to the process of the aedeagus or penis, peos. Gender masculine.
External morphology. Macropterous or submacropterous, tegmina reaching abdomen apex or longer than abdomen. Length 2.80 mm to 5.63 mm (average 4.22± 0.72 mm). Crown produced medially or not produced; anterior margin of crown shagreened; disc smooth, concave. Coronal suture about half as long as medial length of head. Head as wide as or slightly wider than pronotum. Transition from face to crown rounded. Ocellus dorsally submarginally on crown, large, close to compound eye. Length of antenna, about one third length of body (e.g. Figs 5i, 10e, 12c, 15b). Clypeus longer than wide; rectangular or margins divergent distally. Genae slightly notched below eye. Clypeus margins divergent. Pronotum lateral margin narrow, carinate. Tegmina with narrow or reduced appendix, confined to posterior margin, not extended around wing apex; with four apical cells, three anteapical cells, inner anteapical cell open. Hind wing in all species as long as tegmina but variable in width; narrow, 2.8–2.9 times longer than wide, with postcubitus and first vannal veins short, jugum reduced and sometimes crossvein mcu absent; hind wing wide, 1.9–2.1 times longer than wide, with postcubitus and first vannal long and jugum large. Profemur basally with 6–14 short, thick setae in row AV, intercalary row with 8–16 long, thin setae, 3–4 times longer than AV setae; distally with single subapical long thick AM seta (Fig. 7k); numbers variable between species and specimens. Protibia macrosetae 1+4, mesotibia 4+4. Metafemur distally seta 2+2+1, with basal seta longer than distal setae, medial pair of unequal length, distal pair of equal length. Metatarsomere I distal plantar surface with four platellae with rounded apex and one seta with acute apex. Metatarsomere II with three rounded platellae and one acute seta on plantar surface. Nymph with acute crown, triangular in all examined specimens, 1.24–1.45 times longer medially than next to eye. Head and pronotum widths greater in nymphs of adults with long wings and blunt crown than nymphs of adults with submacropterous wings and acute crown.
Male, female and nymph. Colour. Adult ground colour ochraceous to stramineous, or yellow (Fig. 5a). Crown with brown to dark brown marking (e.g. Figs 5b, 8a, 12a, 13a, 17a) and with single amorphous to circular dark brown to black marking on disc (e.g. Figs 5 d–5f), or unmarked (e.g. Figs 5 h–5l). Pronotum immaculate or with few or numerous paired brown or dark brown spots. Scutellum immaculate or marked. Tegmina translucent or cells and veins marked and lined with brown to dark brown pigment or markings in Rondekop specimens of D. diacaenus with longitudinal lines (Figs 5d, 5e). Face with clypeus with brown horizontal arcs, marking on dorsum when present, extending marginally into clypeus; clypellus immaculate or marked with brown; lora with some brown markings. Suture of genae brown, with small brown spot medially near suture. Nymph ground colour as in adult, crown-face apex immaculate.
Male. Genitalia. Genital capsule usually longer than wide in lateral view (e.g. Figs 1b, 7b, 9c), or as long as wide (e.g. Figs 4c, 16b); anterior apodeme present, variable, wide and lobular, e.g. D. arctus (Figs 7a, 7b) or narrow, e.g. D. diacaenus (Figs 1a, 1b); basolateral membranous cleft present; anal tube and subgenital plate extending beyond posterior margin of pygofer lobe, except in D. arctus and D. triacaenus where they are of similar length (Figs 7b, 14b). Anal tube inserted about half way into pygofer; tergite X ventrally with sclerotized or membranous recess, for apices of preatrial aedeagal paraphysis; ventroposterior margin sclerotized, and D. thigmacaenus with acute paired bipinnate process (Fig. 11b). Pygofer lobe variable: Simple, digitate, posteriad, narrow, 1/3–1/4 width of pygofer as in D. diacaenus (Fig. 1b), D. lissus (Fig. 2b) and D. colopeus (Fig. 4c) or slightly wider (about half as wide as width of pygofer), curved dorsomedially in D. viraktamathi, Fig. 16b. Complex, broadly triangular, with two short sclerotized blunt teeth apically and subapically, in D. copeus (Fig. 9c). Complex with membranous and sclerotized process, in D. arctus (Fig. 7b). Complex, ventrobasally rounded, about half as wide as base of pygofer, apex with sclerotized elongate, acuminate, ventroposteriad process, in D. thigmacaenus (Fig. 11b), D. tetracaenus (Fig. 13b) and D. triacaenus (Fig. 14b). Pygofer lobe with medial surface with many short setae, e.g. D. colopeus (Fig. 1a), D. diacaenus (Fig. 2a setae not drawn) and D. lissus (Fig. 3a).
Subgenital plate with apex broadly to narrowly rounded or acute in D. colopeus (Fig. 4b); from about as long as wide (D. triacaenus, 1.1 times longer than wide, Fig. 14c) to 1.9 times as long as wide (D. diacaenus, Fig. 1c); macrosetae in irregular rows in distal lateral half, medial row usually with thicker, shorter macrosetae, longer and thinner setae dorsomarginally; lateral margin curvate in most species, or angulate in D. lissus (Fig. 3c), laterobasal margin convex or straight, but shallowly concave in D. thigmacaenus (Fig.11c); medial margin straight, subparallel or divergent.
Valve ellipsoid or rhomboid, with anterior apodeme-like process in D. colopeus (Fig. 4b), D. arctus (Fig. 7c), D. diacaenus (Fig. 1c), D. lissus (Fig. 3c) and sometimes D. viraktamathi, absent in D. copeus (Fig. 9b), D. tetracaenus (Fig. 13c), D. triacaenus (Fig. 14c) and D. thigmacaenus (Fig. 11c); articulated with subgenital plate.
Style positioned medially or subapically in subgenital plate. Style elongate; apophysis about one third or less total length, compressed (Figs 3g, 7h) or of similar proportions in dorsal and lateral view (e.g. Figs 1h, 4e, 16g) or depressed (Fig. 9f), or acuminate (e.g. Fig. 11f) and sometimes with elongate, medial process (Figs 13g, 14g); apophysis ventrally finely serrate, smooth in D. thigmacaenus; preapical lobe variable, reduced or right angled; anterior lateral arm rounded or acute, longer than anterior medial arm.
Connective usually transverse U- or C-shaped; stem reduced, represented by concave, convex or straight barlike structure, arms variable, shorter than transverse section, right-angled, curvate or straight (e.g. D. diacaenus Fig. 1k, D. lissus Fig. 3p) or longer than transverse section (e.g. D. thigmacaenus Fig. 11g, D. viraktamathi Fig. 16i).
Aedeagus with preatrium produced into gracile, paired process, base of process curved anteriad, depressed, subbasally recurved widely or narrowly posteriad. Apex of process reaching tergite X or shorter; apex acuminate (e.g. Figs 1m, 1n, 3i, 3j, 9d, 9e) or blunt (Figs 4e, 4h), ventrally finely serrate (e.g. Figs 1m, 3h) or acanthoid (Figs 13d, 14d). Process elongate, tubular (e.g. D. diacaenus (Fig. 1n), D. lissus (Fig. 3i), D. arctus (Fig. 7d)) or shorter and thicker in D. colopeus (Fig. 4e), base right-angled in D. thigmacaenus (Fig. 11d); weakly connected subbasally to ventral margin of connective. Aedeagal shaft either with apex membranous (D. diacaenus (Figs 1d, 1e), D. colopeus (Fig. 4f), D. tetracaenus (Fig. 13d), D. viraktamathi (Fig. 16e)), entire shaft membranous (D. colopeus (Fig. 4f)), or entirely sclerotized (D. lissus (Fig. 3d), D. arctus (Fig. 7d), D. copeus (Fig. 9d), D. thigmacaenus (Fig. 11d), D. triacaenus (Fig. 14e)). Shaft adorned with short paired spine, dorsally or ventrally or laterally. Gonopore various positions and shapes. Dorsal apodeme of aedeagus variable, produced but shorter than shaft, or adpressed (e.g. Figs 3d, 3e, Figs 9d, 9e), often inverted C-shaped with compressed anteriad arms, or T-shaped, or Y-shaped or with arms contiguous or with apodeme dissociated from shaft (Fig. 16e) and X-shaped in dorsal view (Fig. 16d).
Female. Genitalia. Sternite VII transversely rectangular, with posterior margin excavated to variable depth and width, or truncate. Posterior margin diagnostic for some species. Sternite VIII, positioned dorsad of sternite VII, weakly sclerotized, indicated as dashed lines in drawings, e.g. Figs 1l, 2c, 3n. Valvula 3 with 10–20 distal, marginal and submarginal macrosetae in 1–3 irregular apical rows. Valvula 2 serrate with large, rounded teeth and small, acute teeth in cavity between rounded teeth; apical half of valvula 2 denticulate. Valvula 1 lanceolate, with marginal, striate microsculpture, at apex angled at about 45°; medial and basal microsculpture parallel. Some variations within species and unique features were observed in the first pair of valvifers. Valvifer 1 in D. colopeus, D. diacaenus and D. lissus about as wide as long. Within this group, D. lissus had the ventral margin narrowed and lobular (Fig. 3l), whereas the others had the ventral margin uniformly rounded (Figs 3k, 3m). In D. arctus, D. copeus and D. thigmacaenus valvifer 1 longer than wide (e.g. Figs 7k, 7l) and D. thigmacaenus with valvifers fused membranously along apical margin. In D. arctus valvifer 1 with base rectangular, whereas in the others the base was rounded or acute. In D. colopeus, D. copeus and D. diacaenus the posterior margin is uniformly rounded, but in D. copeus the subbasal margin is emarginate. In D. viraktamathi valvifer 1 is merged into single crescentic or trapezoid structure (Figs 16j, 16k).
Relationships. This genus is placed in the tribe Bonaspeiini and is characterized primarily by the configuration of the aedeagal processes that are elongated, paired and connected to the preatrium. Such structures occur in several groups of Cicadellidae and may be attached to the aedeagus or connective, or freely articulated between them (paraphyses).
Below follows a discussion on some features of the male genital capsule in an attempt to add or improve diagnostic features of species mostly described by Theron and Davies and in the context of the new species below and the multitude of new genera and species in Bonaspeiini still awaiting description.
The connective in Discolopeus is considered as U- or C-shaped, with the stem reduced. Most of the 21 genera listed under Bonaspeiini by Zahniser & Dietrich (2013) have a Y-shaped connective, with a stem, shorter than or as long as the arms, except Bloemia, Hadroca, Kaapia and Salsocolila, which have the stem longer than the arms. Most species of Bretega (Stiller 2016) have a short stem, except B. quattuspiverpa, where the stem is longer than the arms. Most species of Cerus Theron have the stem distinctly short, but in C. ladius Theron, the stem is longer than the arms. Re-examination of variation in the shape of the connective is needed in diverse genera such as Bonaspeia, Caffrolix and Curvostylus but all appear to have a short stem. Bloemia and Hadroca require revision, with many new species expected (M. Stiller, personal observation). The former has the stem and arms of similar proportions. The latter has the stem much longer than the arms. In Johanus Theron the stem is as long as the arms, and with length and width corresponding. Thus it is possible to separate groups of genera within Bonaspeiini and Athysanini based on whether the connective is Y- or U-shaped connectives and on the proportions of the stem and arms. Members of the large and poorly defined tribe Athysanini in the Ethiopian Region exhibit considerable variation in the form of the connective but require further comparative study; e.g., Awasha Heller & Linnavuori (connective fused to aedeagus, stem length not discernable, arms parallel), Brachypterona Lindberg (Y-shaped, stem and arms equidistant), Dagama Distant (Y-shaped, stem and arms equal, or stem longer), Houtbayana Linnavuori (Y-shaped, stem and arms equal), Moskgha Deeming & Webb (Y-shaped, stem shorter than arms), Okaundua Linnavuori 1969 (Y-shaped, proportions not described or illustrated).
Other members of Bonaspeiini have distinct aedeagal atrial processes, in proximity to the shaft, with a short preatrium articulated with the connective. The aedeagus in Cerus has an elongate sclerotized shaft with spines at various positions on the shaft and an elongate or reduced dorsal apodeme. The aedeagus of Cerus piketensis Theron bears some resemblance to that of Discolopeus species, that has the ventral process on a somewhat elongated atrium and an elongated preatrium. The sternite VII of C. piketensis is transversely rectangular to trapezoidal, with the posterior margin wide and shallowly invaginated, and with the elongate sternite VI in the dissected and cleared abdomen visible as two circular to elliptic areas. The first valvifer is rhomboidal, with its base free. In Renosteria the aedeagal process is usually close to the base of the shaft and the dorsal apodeme well developed. Renosteria cedarana Theron bears resemblance to Discolopeus species in having the basal process arising from the atrium, with the preatrium short and articulated with the connective and a reduced dorsal apodeme. The sternite VII of R. cedarana is longitudinally trapezoid, and the first pair of valvifers elongated and joined membranously at their base. In Refrolix ruensis Theron the sternite VII and valvifer 1 resemble that of D. colopeus and D. diacaenus. Undescribed leafhoppers have been examined with short preatrial processes with elongate atrial processes.
Of secondary importance is shape of the pygofer lobe. Four shapes and configurations occur in Discolopeus: 1. Narrow or wide, simple; 2. Bilobate with elongate processes; 3. Bilobate with short processes; 4. Acuminate with sclerotized ventrad or posteroventrad process. In contrast, other members of the tribe exhibit less interspecific variation in this structure. In Cerus the lobe is as wide as the pygofer with a dorsomedial or medial sclerotized curvate or straight acuminate, sclerotized process, usually not projecting beyond the lobe margin. In Renosteria the lobe is narrower, about half the width of the pygofer, short, triangular (obtuse or acute) with a short, acute, apical or usually dorsomedial process. Caffrolix has the lobe narrow or broadly rounded, sometimes with a dorsal acuminate process or without a process. Bonaspeia and Curvostylus have a triangular lobe with membranous apex and dorsomedial straight or curvate acuminate process. In Bretega species it is least modified, short and broadly rounded (Stiller 2016).
The shape of the subgenital plate is also important. Important features include the shape of the lateral margin, e.g. rounded or sinuous; posterior margin narrow or widely rounded; and arrangement of macrosetae, e.g. multiple rows or single row.
Other features include wing development. The new genus is similar to Cerus Theron and Renosteria Theron with regard to wing length. With regard to head shape and nature of the hind wing in Discolopeus, three species (D. diacaenus, D. lissus, D. colopeus) have an elongate crown and narrow hind wing, while six species (D. arctus, D. copeus, D. viraktamathi, D. tetracaenus, D. triacaenus, D. thigmacaenus) have a short crown with well developed hind wing.
Discolopeus somewhat resembles Capeolix Linnavuori with regard to wing length, but less in habitus and colour. Generally Capeolix has a rounded crown, roundly merged with face, a simple aedeagus with paired structures at the apex of the shaft, and also is in need of revision (M. Stiller, personal observation). According to Zahniser & Dietrich (2013) Tetartostylini and some subtribes in Selenocephalini possess aedeagal paraphyses, structures similar to paraphyses or pseudostyles. For example some similarities occur in Afrascius Linnavuori and Libengaia Linnavuori, although both are regarded as Opsiini (See Zahniser and Dietrich 2013). Even genera in Selenocephalina under Selenocephalini such as in Foso Linnavuori & Al-Ne’Amy, Gannia Theron and some species of Maichewia Linnavuori & Al-Ne’Amy, have some resemblance to Discolopeus in the pygofer lobe or aedeagus. Nevertheless, the smooth (not transversely striate) anterior margin of the head is supports placement of Discolopeus in Bonaspeiini.
description: Published as part of 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, pp. 201-244 in Zootaxa 4559 (2) on pages 203-206, DOI: 10.11646/zootaxa.4559.2.1, http://zenodo.org/record/2626811