Ommatissus Fieber, 1875: 353; Melichar, 1914: 124; Chou et al., 1985: 42; Asche & Wilson, 1989: 130. Type species: Ommatissus binotatus Fieber, 1875.
Diagnostic characters. Small-sized tropiduchids, body slender. Coloration ranging from pale stramineous to dark brownish, with at least one distinct blackish spot present on each side of pronotum. Vertex (Figs 2, 5, 8, 11) pentagonal, broader than medially long; anterior margin obtuse-angled convex, posterior margin slightly concave, marginal carinae ridged; disc of vertex depressed, median longitudinal carina inconspicuous or missing. Frons (Figs 3, 6, 9, 12) longer in middle than maximum breadth, with distinct median carina, each lateral half flat or shallowly concave. Postclypeus short, triangular, broadly rounded, with or without median carina. Rostrum with terminal segment as long as broad. Compound eyes almost hemispherical. Ocelli small. Antennae with scape small, ring-like; pedicel cylindrical, about 3.0– 3.5 times as long as scape, pedicel distally slightly expanded. Pronotum (Figs 2, 5, 8, 11) tricarinate, anterior margin produced, posterior margin obtuse-angled excavated, median carina reaching hind margin, carinae of disc distinctly ridged, between them shallowly concave with a small circular depression medially on each side of central ridge, with a single carina between eye and tegula. Mesonotum (Figs 2, 5, 8, 11) tricarinate. Hind tibia each with 2 distinct lateral spines, spinal formula of hind leg (5–8)–(5–8)– 2. Tegmina (Figs 1, 4, 7, 10) slender and rather narrow, broadest distad of claval apex, brachypterous form 2.3–3.3 times longer than maximum breadth, macropterous forms 2.6–3.4 times as long as maximum breadth, claval apex at middle or slightly distad of midpoint of tegmen; veins distinct without obviuous bristles or hairs, main stems of veins straight, cross veins only in distad between Sc+R and M, M and Cu 1 a, and Cu 1 b and apex of clavus. Wings (Figs 17, 28, 49) mostly hyaline, Cu distally forked, other veins simple, only two cross veins present, between M and Sc+R shortly distad of coupling apparatus and M and Cu 1 a, respectively.
Male genitalia. Pygofer (Figs 18, 29, 40, 50) symmetrical simple ring shaped, ventral margin distinctly longer than dorsal margin, dorsal margin deeply excavated to accommodate anal tube. Anal tube (urite X) (Figs 21 –22, 32–33, 43–44, 50, 53) short, anal style (paraproct and epiproct) rather short. Gonostyli (Figs 18 –20, 29–31, 40– 42 50–52) bilaterally symmetrical, in side view varying in length from almost as long as broad to 2.3 times as long as broad, distally either rounded or pointed, with a strong hook-like process arising from laterodorsal margin, acute tip bent laterad or lateroventrad, with tooth-like process arising from inner dorsal margin, pointed to inner side. Periandrium (Figs 44, 22–23, 33–34, 54– 55) surrounding aedeagus only at base, dorsally connected with ventrobasal margin of anal tube, shape various. Aedeagus (Figs 22 –23, 33–34, 43–44, 54– 55) elongate and tubular, shaft slender in lateral view, with phallotrema apical or slightly subapical and ventrally exposed.