Genus Nesoclutha Evans, 1947

Nesoclutha Evans, 1947: 126; Knight, 1975: 197; Day & Fletcher, 1994: 1220. Type species: Nesoclutha obscura Evans, 1947 . Irinula Ribaut, 1948: 58; 1952: 60; Linnavuori, 1960: 330; Grylls, 1963: 143; synonymised by Vilbaste, 1976: 28. Type species: Cicadula erythrocephalus Ferrari, 1882 .

Description. Head wider than pronotum. Vertex glabrous, longer medially than next to eyes, slightly shorter than interocular width; disc somewhat flat; anterior margin shagreen, roundly produced (Fig. 1 A). Face (Fig. 1 B) wider than long; margin of gena adjacent to clypellus much narrower than ocell-ocular area; latero-frontal sutures extending above antennae to ocelli; clypellus long, narrow, exceeding apex of lora, sides parallel; antennal ledges weak. Ocelli situated on frontal margin of vertex next to corresponding eye, separated from each eye by 1.5 times to twice own diameter. Pronotum large, anterior margin roundly produced, posterior margin shallowly concave (Fig. 1 A); lateral margins short, non-carinate (Fig. 1 C). Forewings (Fig. 1 F) elongate, exceeding abdomen; appendix wide; two subapical cells and four apical cells. Setal pattern at apex of hind femora 2, 2, 1.

Male genitalia. Pygophore (Fig. 1 D, E) wider than long; lateral lobes narrowly rounded posteriorly, emarginate dorsally to near midlength, tapering caudally; posterior margin covered with spicules and spines; macrosetae plumose, over posterior half of lateral surfaces. Tenth segment membranous (Fig. 1 D). Valve broadly triangular (Fig. 1 I). Subgenital plates triangular (Fig. 1 I), reaching apex of pygophore; uniseriate row of macrosetae along ventrolateral margin (Fig. 1 D). Styles with apical process finger-like, turned slightly laterally; lateral lobe well developed, bearing setae dorsally (Fig. 1 I). Connective Y-shaped, arms as long as stem, with distinct membrane marginally (Fig. 1 J). Aedeagus with shaft short, apex acute, directed dorsally (Fig. 1 D, H); gonopore large, subapical on ventral surface (Fig. 1 J).

Distribution. China, Australia, New Zealand, Turkey, Iran, Japan, Europe, Africa, Southern Asia, Indonesia, New Caledonia.

Remarks. Nesoclutha is similar to Balclutha (Macrostelini) but can be distinguished from the latter by the head wider than pronotum and vertex obviously longer medially than next to eyes and aedeagal shaft more robust than latter (Fig. 1 A, H), with gonopore large and subapical on ventral margin (Fig. 1 J). It differs from all members of the tribe in China by the laterally membranous connective (Fig. 1 J).