The endemic New World eucheiloid complex is distinguished from the other complexes (thyreopteroid, eurycoleoid, somotrichoid, and pericaloid) of pericaline Lebiini by securiform labial palpomere 3, serrate-setose margins of the pronotum, and flattened stylomere 2 of the ovipositor. The geographical range of eucheiloids extends from northern Argentina to southernmost United States (Brownsville, Texas). All taxa are believed to be arboreal. A key distinguishes among the three genera and 16 species, and each taxon is characterized in terms of structural features, habitat, and geographical distribution. The genera are: Hansus, new genus (generitype—H. reichardti, new species); Inna Putzeys (generitype—Inna punctata Putzeys = Polystichus boyeri (Solier)); and Eucheila Dejean (generitype—Euchyla flavilabris (Dejean)). Seven new species and one new subspecies are described: Hansus reichardti (type locality—Guyana, EssequiboR.. Morrabali Ck.); Inna palpalis, I. atrata arbor, and I. inpa (type locality—Brazil, Amazonas, near Manaus); I. purpurea (type locality—Brazil, Amazonas, 60 km n. Manaus); I. splendens (type locality—Venezuela, Aragua, Rancho Grande); Eucheila adisi (type locality—Brazil, Amazonas, 60 km n. Manaus); and E. cordova (type locality—México, Veracruz, Cordova). The following new synonymies of specific names are proposed (valid names listed first): Inna costulata Chaudoir, 1872 = I. granulata Chaudoir, 1872; Inna boyeri (Solier, 1835) = I. punctata Putzeys, 1863, and I. texana Schaeffer, 1910. A reconstructed phylogeny of the eucheiloids, based on analysis of 60 character states included in 33 characters, shows that Hansus is sister group of the ancestral stock of Inna + Eucheila. Evolutionary modifications have affected principally body size, head and mouthparts (feeding and associated adaptations), reproductive structures, and features of the body surface thought to be associated with avoidance of predators (concealment and flash coloration). Diversification may also have involved differentiation by habitat (type of forest occupied). The principal theater of evolution has been tropical South America, with incursions both southward and northward. Middle America has been invaded by five lineages, probably during Cenozoic time, from Middle Tertiary to the Quaternary. Of these lineages, three are represented in Middle America by endemic species: E. cordova, I. planipennis Bates, and I. nevermanni Liebke. Two lineages are represented by species whose ranges extend northward from South America: I. costulata Chaudoir and I. boyeri (Solier).