Urothripine

Distinguishing the Urothripine genera

1. Compound eyes each with at least 30 facets (Figs 40–41), all equal in size; antennal segment III slender, usually 3–4 times as long as wide and not narrowed sharply to base; mid and hind tarsi 2-segmented; fore tarsal hamus directed ventrally; metathoracic epimera each with a prominent lateral seta....................................................... 2

-. Compound eyes never with more than 15 facets (Figs 27–28), some dorsal facets much larger than others; antennal segment III almost globose, scarcely 2 times as long as wide and sharply narrowed to basal stem (sometimes fused to segment IV or to IV+V); mid and hind tarsi 1-segmented; fore tarsal hamus, when present, directed laterally; metathoracic epimera with or without such a seta.................................................................................... 3

2. Head projecting over bases of first antennal segment (Fig 41); eyes almost holoptic but with no facets ventrally; head with genae narrowing to base; prosternal basantra present and transverse.................................... Octurothrips

-. Head projecting strongly in front of eyes with antennae arising at apex (Fig. 40); compound eyes globose on dorsal and ventral surfaces; head sharply narrowed to base; prosternal basantra reduced to weak sclerites placed anterolaterally.... Habrothrips

3. Prosternal basantra transverse across anterior margins of ferna......................................... Trachythrips

-. Prosternal basantra absent or reduced to small anterolateral sclerites............................................. 4

4. Anterior margin of head with prominent setae, rarely reduced to a single small pair (Figs 26–32)...................... 5

-. Anterior margin of head with no prominent setae (Figs 33–38)................................................. 6

5. Antennal segment III narrowed at apex and distinct from narrowed base of IV (Fig. 9); maxillary stylets close together medially in head..................................................................................... Bradythrips

-. Antennal segment III broad at apex and close to broad base of IV, segments III–V weakly to closely fused; maxillary stylets about 0.3 of head width apart................................................................. Stephanothrips

6. Fore tarsus with hamus.......................................................................... Urothrips

-. Fore tarsal hamus absent................................................................... Amphibolothrips