Irridiculum, 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 : 441-442

Irridiculum gen. nov.

Type-species: Irridiculum deformatum sp. nov., the only included species.

Etymology. irridiculum (neuter noun), Latin for “laughing-stock”.

Diagnosis. Immediately recognizable by pointed processes on both the tip of the head and the humeral angles of the thorax. Tylus produced as erect, hornlike process longer than 2 × diameter of eye; frons unicarinate; crown deeply sulcate behind ocelli ( Fig. 15 A); antenna projecting dorsad, pedicel deeply excavated, enclosing short postpedicel, and with prominent ventral “lip” ( Fig. 25 C); basiconic sensillum broadly triangular with single median angle; pronotum strongly arched, humeral angles produced as laterally-directed hornlike processes, tips upturned; scutellum globular, base longer than pronotum, tip a slender spine arising from middle of posterior margin, as long as scutellar base. Tegmina with venation carinate, forming meshwork of irregular cells apically, appendix broad and oblique, extending nearly from wing tip across end of blunt-tipped clavus ( Fig. 43 A). Hind wing slender, pointed, with 3 long, apical cells and large, wrinkled appendix ( Fig. 43 B). Hind tibia short and stout ( Fig. 15 A), its pecten with 10 black-tipped spines; pecten of basitarsomere with 12 such spines in irregular row; pecten of second tarsomere with 7 such spines. Male unknown. Ovipositor 2nd valvulae leaflike, 1.4 mm long, broad, 3 × as long as wide near base ( Fig. 17B ). Length: 9–10 mm.

Remarks. The shape of the antennal basiconic sensillum appears to be unique. The remarkable body shape appears to combine features of various other genera. For example, the scutellar shape is similar to that of Blastocaena Maa (1963, fig. 26N) with the apical process arising from the middle of the posterior margin; but that genus has a forked basiconic sensillum ( Fig. 24 C) as in Sigmasoma E. Schmidt. Like the latter genus, Irridiculum has a head process and numerous costal cells, and like Maxudea E. Schmidt it has prominent humeral processes. The similarity of the new genus to Maxudea is entirely superficial. The pronotal processes of Maxudea are swept backwards ( Maa 1963, fig. 15A) and the scutellar process arises from a nearly flat scutellum ( Maa 1963, fig. 28A), as in most “Enderleiniinae,” instead of having a bulbous and deeply grooved scutellar base as in other Machaerotini.

Figures

FIGURES 10 – 16. Examples of Clastopterinae (10 – 11) and Machaerotinae (12 – 16). 10, Clastoptera testacea Fitch; 11, Iba cuneata Schmidt, lectotype; 12, Allox transfigurata; 13, Metaenderleinia nervosa Lallemand; 14, Machaeropsis dramatica (genital capsule as in Metaenderleinia); 15, Irridiculum; 16, Hindoloides bipunctata (Haupt), male genitalia typical of Machaerotini and Hindoloidini. A, habitus; B, male genital capsule (small styles as in 16 B omitted in 12 – 13 B). Scale line for habitus drawings: 1 mm (Fig. 11 A slightly larger).

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 40 – 46. Wings of Clastopteridae: Clastopterinae (40 – 41), Zygonini (42) and Machaerotinae (43 – 46), tegmina (A) and hind wings (B). 40, Clastoptera globosa; 41, Iba sp. nov.; 42, Pseudomachaerota olivacea, holotype; 43, Irridiculum deformatum, holotype; 44, Conditor collatatus, holotype (redrawn from Distant 1916, fig. 141, as the unique specimen is no longer in the BMNH); 45, Allox transfigurata, paratype; 46, Aphrosiphon bauhiniae, from China (1935).

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.