1. Large species (total length about 3.5 mm), almost evenly yellowish brown dorsally (Fig. 2A ); the clavii and base of scutellum slightly darker. Pronotal anterior angles pointed, partially wrapping the eyes. Sri Lanka....... Isometopus cuneatus (Distant)
– Smaller species (total length between 2.0 and 2.5 mm), with a more complex dorsal pattern, including different colours. Pronotal anterior angles never pointed and partially wrapping the eyes.................................................2
2. Scutellum yellowish, with an elongate, apically pointed, dark patch medially (Fig. 2B). Pronotum and hemelytra yellowish white, with apical areas of coria black............................................... Isometopus mahal (Distant)
– Pronotum, scutellum, and hemelytra differently coloured...................................................... 3
3. Scutellum almost evenly dark brown, the apex barely lighter (Fig. 2D)........................ Isometopus wolskii, n. sp.
– Scutellum never evenly coloured......................................................................... 4
4. Pronotal disk dark brown, with the narrow lateral margins pale brown to slightly orange on inner parts (Fig. 2C).......................................................................................... Isometopus webbi, n. sp.
– Pronotal disk dark brown, with anterior angles and broad posterior margin yellowish. Apex of scutellum yellowish (Fig. 2E).................................................................... Isometopus yoshizawai Yasunaga & Duwal