Hemizygon, Andrew Hamilton, K. G., 2014

Andrew Hamilton, K. G., 2014, The old-world Zygonini tr. nov. (Hemiptera, Cercopoidea, Clastopteridae), with new taxa from the related Machaerotinae, Zootaxa 3768 (4), pp. 437-459 : 447-448

Hemizygon gen. nov.

Type-species. Pseudomachaerota saturnus Linnavuori, 1973 .

Etymology. hemi- half, zygon (n noun), Greek for “yoke.”

Diagnosis. Head much narrower (0.70–.65×) than pronotum, lateral margins of pronotum almost as long (0.8×) as interocular distance; antennal ledges not prominent; antenna with short postpedicel partially withdrawn into tip of pedicel, bearing arista on anterodorsal edge, a central, flattened basiconic sensillum situated in a circular depression at the tip of a low eminence (as in Pseudomachaerota , Fig. 26 C) but with sensillum triangular, widest transversely, pointed caudally, and behind this a nearly circular pit (containing 4 coeloconic sensilla) with a tooth on outer edge of rim (as in some Pseudoclastoptera , Fig. 31 C); rostrum extending beyond mesotrochanters but not beyond hind coxae; pronotum punctured, with obscure median ridge; scutellum sulcate. Tegmina densely punctate, opaque, veins strongly carinate apically, forming 3 anteapical cells of which central one is smallest, nearly square, half as long as outer anteapical cell, and one-third as long as inner one, closed basally by bulla bearing weak crossvein ( Fig. 8 A). Hind wings each with 2 hooks on costal margin, 1 at tip of triangular process. Hind tibia short and broad, their pectens each with 7–10 spines, those of basitarsomere with 8 spines, of second tarsomere with 6 spines covered by long setae. Male pygofer weakly scleritized, deeply notched near middle at level of lower surface of anal tube and with three pairs of processes, ventrolateral two small and ovoid, dorsal process larger and more nearly triangular, articulated; basal segment of anal tube (X) very narrow, widening ventrad, with long basal extensions; paraprocts nearly as long as 11th segment including epiproct. Style as long as pygofer, with ventral channel and short, lobed tip. Theca heavily sclerotized, stout, in lateral aspect curved apically, tapered to point ( Fig. 8 C), in posterior aspect narrowed just before enlarged, cordate base, tapered beyond midlength, fringed with serrate flange around gonopore on posterior face ( Fig. 8 D). Ovipositor 1.6 mm long, tapered on apical third to a narrow point, with a very low tooth on dorsal margin just beyond midlength ( Fig. 17J ). Length: 5.5–7 mm.

Distribution. Ethiopian.

Included species. Hemizygon grande (Maa) , from South Africa and S. saturnus (Linnavuori) from central Africa, both new combinations from Pseudomachaerota .

Remarks. The small head compared to the very broad and bulging pronotum gives these insects the appearance of Taihorina Schumacher (a basal genus in “ Machaerotidae ” of Maa 1963). The pronotum is more humped than in Zygon ( Figs 1 A–B), but less so than in Ambonga ( Figs 3 A–B).

The antenna of the type species most resembles that of Pseudoclastoptera but the coeloconic sensilla are few and situated in a nearly circular pit without marginal setae. The antennae of the other species, S. grande , are not known.

Both males and females of S. saturnus collected by Linnavuori from Upper Volta are deposited in AMNH. These show considerable sexual dimorphism, the male being only 5.5 mm long and boldly patterned with a prominent bulla on the tegmen ( Fig. 8 A) while the female is considerably larger (7 mm) and almost uniformly colored, but show identical barcodes (BOLD: CNC#HEM402129–30). The only known specimens of P. grandis (Maa) , females from South Africa, are also uniformly colored.

Figures

FIGURES 18 – 32. Antennae of Clastopteridae: Clastopterinae (18 – 20) and Machaerotinae: Hindolini (21 – 23), Machaerotini (24 – 25) and Zygonini (26 – 32, boxed set). A, lateral aspect of head; B, detail of antennal and antenna ledge; C, tip of antenna, showing postpedicel; D, detail of postpedicel showing detail of pits, revealing 4 enclosed coeloconic sensilla in communal pits. 18, Clastoptera; 19, Sepullia; 20, Grellaphia; 21, Chaetophyes; 22, Hindola; 23, Allox; 24, Blastocaena; 25, Irridiculum; 26, Pseudomachaerota cucullata; 27, Zygon, with detail showing basiconic sensilla (b) and coeloconic sensilla (c) of various types (shown in greater detail in Fig. 38); 28, Ambonga lanceolata (Zygonini); 29, Ambonga apicenotata syntype with insert showing sensilla at base of arista; 30, Pseudoclastoptera irrubesco sp. nov., holotype; 31 – 32, Pseudoclastoptera invidia sp. nov., male holotype (32) and unassociated female (31).

FIGURES 5 – 9. Zygonini, dorsolateral aspect (A); male subgenital plates (B), ventral aspect; (C), genital capsule and theca (with style in 7 – 9), lateral aspect; (D), theca, caudal aspect; (E) habitus, dorsal aspect. 5, Pseudoclastoptera irrubesco (style as in Pseudomachaerota); 6, Pseudomachaerota olivacea, female holotype; 7, Pseudomachaerota cucullata; 8, Hemizygon saturnus; 9, Zygon desegregatum. Scale line for habitus drawings: 1 mm.

FIGURES 17 A – R. Ovipositor shapes in 17 genera and subgenera of Clastopteridae: Zygonini (A, G – J, Q), Machaerotinae (B – D, K, R) and Clastopterinae (E, F, L – Q). A, Zygon desegregatum, paratype; B, Irridiculum deformatum, holotype; C, Allox transfigurata, paratype; D, Taiorhina geisha Schumacher; E, Grellaphia costalis Schmidt; F, Beesoniella sylvestris Lallemand; G, Pseudomachaerota olivacea, holotype; H, Ambonga lanceolata; J, Hemizygon saturnus (as in Ambonga apicenotata); K. Machaeropsis dramatica; L, Tremapterus (Nyanja) bimaculata Synave, holotype; M, Tremapterus (Abbalomba) typica Distant; N, Tremapterus (Patriziana) janus Linnavuori; O, Tremapterus (s. s.) rufus (Thunberg); P, Sepullia fuscolimbata Lallemand; Q, Pseudoclastoptera irrubesco; R, Machaerota sp. Scale line: 1 mm.

FIGURES 1 – 4. New species of Zygonini, lateral aspect (A), dorsolateral aspect with pin erased (B), facial aspect (C) and hind legs (D). 1, Zygon desegregatum, male (A) and female (B) paratypes; 2, Pseudomachaerota cucullata, holotype; 3, Ambonga lanceolata, holotype; 4, Pseudoclastoptera irrubesco, holotype. Figs 1 and 3 A – B to same scale; Figs 2 and 4 A – B slightly larger; Figs C and D largest. Scale line: 1 mm.