Abstract. The tribe Hoplophorionini Goding, 1926, includes 105 species of treehoppers in 10 genera. All are apparently subsocial and lack mutualism with honeydew-collecting hymenopterans. In many species, parental investment in offspring is unique because of a specialized kicking defence (described herein) and construction of extra-ovipositional punctures in the host tissue through which nymphs feed. The tribe occurs from Canada to Chile, with most generic diversity in Central America but most species diversity near the equator. Three genera, Stalotypa Metcalf, Ramosella, new genus and Stirpis, new genus, are endemic to the Greater Antilles but do not constitute a monophyletic group; the first two genera appear most closely related to Turrialbia, new genus, from Costa Rica. Host plant specializations and other biological attributes are summarized for genera and species. A phylogenetic analysis of 23 hoplophorionine species produced 9 minimal-length cladograms that were similar in many respects. Potnia Stål appears to have retained the greatest number of ancestral features. Aposematic teneral coloration of adults probably evolved once. The modification of the ancestral kicking behaviour by the first hoplophorionines appears to have released them from a constraint on pronotal form.

Diagnoses are given for adults of all genera and, when possible, for immatures. A key is presented for the 10 genera; three are described as New Genera based on the cladistic analysis: Ramosella, Stirpis, and Turrialbia. Three New Species are described: Ramosella thalli, Stirpis jamaicensis, and Turrialbia felina. The genus Micropepla Sakakibara is considered a junior synonym of Ochropepla Stal, New Generic Synonymy. Umbonia terribilis Walker is moved from synonymy under Alchisme virescens (Fairmaire) to a New Synonymy under Umbonia reducta Walker. The subspecies Platycotis vittata vittata (Fabricius), P. vittata lineata (Fairmaire), and P. vittata quadrivittata (Say) are returned to synonymy with Platycotis vittata (Fabricius), Reinstated Specific Synonymies. Three species are Reinstated as valid: Alchisme obscura (Walker) and A. veruta (Fowler), both from synonymy under A. turrita (Germar); and Umbonia reducta Walker, from synonymy under U. crassicomis (Amyot & Serville). Five New Combinations are proposed: Alchisme antigua (Funkhouser), referred from Umbonia; A. sordida (Germar), referred from Platycotis; A. sagittata (Germar), elevated from subspecific rank under Platycotis vittata; Ochropepla mourei (Sakakibara), referred from Micropepla; and Ramosella dominicensis (Ramos), referred from Platycotis. Platycotis nigrorufa (Walker), P. cornuta Plummer, P. salvini (Fowler), and P. fuscata (Fowler) were previously unplaced to subgenus; the first is referred to Platycotis (Lophopelta Stal) and the others to Platycotis (Platycotis Stål). Microschaema nigrostrigata Buckton is moved from synonymy under Alchisme recurva (Stål) to a New Synonymy under Ennya dorsalis (Fairmaire) of the tribe Polyglyptini, subfamily Smiliinae.

A checklist with critical synonymies and indexes to hoplophorionine taxa and host plant associations are provided. Lectotypes are designated for Centrotus vittatus Fabricius, Hoplophora lineata Fairmaire, Membracis venosa Germar, Potnia affinis Buckton, and Triquetra obtusa Fowler.