Key to species of Urothrips

1. Antennal segments I–VIII all distinct from each other with VII–VIII separate but closely joined............... reticulatus

-. Antennal segments VII–VIII fused without suture........................................................... 2

2. Antennal segment III clearly distinct from segment IV........................................................ 3

-. Antennal segment III broadly joined or fused to segment IV................................................... 5

3. Ocellar region of head broadly rounded (Fig. 1).......................................................... tarai

-. Ocellar region of head prolonged over base of antennae (Fig. 4)............................................... 4

4. Antennal segments IV–V fused (Fig. 4)............................................................... junctus

-. Antennal segments IV–V distinct from each other.................................................... gibberosa

5. Ocellar region of head prolonged over base of antennae into two small rounded tubercles (Fig. 3); mesoeusternum with median longitudinal division................................................................................ reedi

-. Ocellar region of head broadly rounded, scarcely overhanging base of antennae (Fig. 5); mesoeusternum anterior margin entire.................................................................................................... 6

6. Antennal segments III–V fused with sutures indicated by constrictions (Fig. 6)........................... kobroi sp.n.

-. Antennal segments III–V articulated but broadly joined (Fig. 2)................................... paradoxus -group