ABSTRACT: The phyline plant bug genus Tytthus Fieber, previously containing 19 species, is revised. Isoproba Osborn and Drake, 1915, incorrectly placed in the subfamily Bryocorinae, tribe Dicyphini, is synonymized as a junior synonym of Tytthus Fieber, syn. n.; the only included species, Isoproba picea Osborn and Drake is transferred to Tytthus, comb. n., as the senior synonym of Tytthus hondurensis Carvalho, syn. n.; and Tytthus koreanus Josifov and Kerzhner, 1972 is synonymized with Tytthus chinensis (Stål 1860), syn. n.; and a lectotype for Tytthus parviceps is designated. The six new species Tytthus femoralis from Cuba, Ecuador, Guatemala, Jamaica, Mexico, and Peru,Tytthus fuscicornis from New Mexico (USA), Tytthus mexicanus from Mexico, Tytthus pallidus from Brazil and Panama, Tytthus uniformis
