ubiquitous                                        Widespread.

uncus.                                                   A solid process arising from the outer edge of the tibial apex and either hooked, curving inwardly or sometimes extending across the apex and projecting inwardly.

uniramose antenna.                      The presence of a single ramus on each antennomere.               

univoltine                                           Animals which only one generation a year reaches maturity

unques                  The claws at the tip of the feet in Diptera.