From the endemic New World halyine genus Brochymena, two genera are recognized. New morphological characters at the generic level are described. Parabrochymena, new genus, with Pentatoma arborea Say as type species, is erected to contain 10 taxa formerly included in Brochymena. New combinations are Parabrochymena aculeata (Distant), P. apiculata (Van Duzee), P. arborea (Say), P. barberi barberi (Ruckes), P. barberi diluta (Blatchley), P. cuspidata (Distant), P. enigmatica (Ruckes), P. florida (Ruckes), P. haedula (Stål), and P. poeyi (Guérin-Méneville). Brochymena is redefined with 20 taxa: B. affinis Van Duzee, B. cariosa Stål, B. carolinensis (Westwood), B. chelonoides Ruckes, B. dilata Ruckes, B. exardentia Ruckes, B. hoppingi Van Duzee, B. humeralis Ruckes, B. laevigata Ruckes, B. lineata Ruckes, B. marginella Stål, B. myops Stål, B. parva Ruckes, B. punctata punctata Van Duzee, B. punctata pallida Blatchley, B. pilatei Van Duzee, B. quadripustulata (Fabricius), B. splendida Ruckes, B. sulcata Van Duzee, and B. tenebrosa Walker. Four synonymies are established: B. marginella Stål = B. carolinensis (Westwood); B. pilatei Van Duzee = B. sulcata Van Duzee; B. laevigata Ruckes = B. myops Stål; B. exardentia Ruckes = B. lineata Ruckes. Lectotypes are designated for B. affinis Van Duzee, B. cariosa Stål, B. myops Stål, B. punctata pallida Blatchley, and B. p. punctata Van Duzee. Species groups of Brochymena are characterized, and a key to all taxa is presented for the first time. As appropriate, for each species of Brochymena, the following are provided: citation of original description, synonymies, type material, diagnosis, description, geographical distribution, taxonomic comments, natural history, and illustrations of important structural characters. Chorological affinities are presented and systematic relationships are hypothesized.