Revision of the Neotropical genus O'Brien, 1999 (Hemiptera, Fulgoromorpha, Dictyopharidae, Nersiini), with descriptions of two new species from Peru and Brazil.

The Neotropical planthopper genus O'Brien, 1999 (Hemiptera, Fulgoromorpha, Dictyopharidae, Nersiini) is revised. Four species are included: (Melichar, 1912) (the type species, from Peru), Song, Malenovský & Deckert, (from Brazil), Song, O'Brien & Bartlett, (from Peru), and (Melichar, 1912) (from Bolivia and Peru). Lectotypes are designated for Melichar, 1912 and Melichar, 1912. All species are described, including habitus photographs and detailed illustrations of the male genitalia. Male and female genitalia are described for this genus for the first time. A key for identification of the species of and a distribution map are provided.