A revision of the genus Planinasus Cresson (Diptera, Periscelididae)

The genus Planinasus Cresson is revised and includes 18 extant and one fossil species. We clarify the status of the three previously described species and describe 15 new species as follows (type locality in parenthesis): P. aenigmaticus (Colombia. Bogota: Bogota (04°35.8`N, 74°08.8`W)), P. neotropicus (Panama. Canal Zone: Barro Colorado Island (09°09.1`N, 79°50.8`W)), P. kotrbae (Ecuador. Orellana: Rio Tiputini Biodiversity Station (0°38.2`S, 76°08.9`W)), P. miradorus (Brazil. Maranhão: Parque Estadual Mirador, Base da Geraldina (06°22.2`S, 44°21.8`W)), P. tobagoensis (Trinidad and Tobago. Tobago. St. John: Parlatuvier (11°17.9`N, 60°39`W)), P. xanthops (Ecuador. Orellana: Rio Tiputini Biodiversity Station (0°38.2`S, 76°8.9`W)), P. argentifacies (Peru. Madre de Dios: Río Manu, Pakitza (11°56.6`S, 71°16.9`W; 250 m)), P. insulanus (Dominican Republic. La Vega: near Jarabacoa, Salto Guasara (19°04.4`N, 70°42.1`W, 680 m)), P. nigritarsus (Guyana. Conservation of Ecological Interactions and Biotic Associations (CEIBA; ca. 40 km S Georgetown; 06°29.9`N, 58°13.1`W)), P. atriclypeus (Brazil. Rio de Janeiro: Rio de Janeiro, Floresta da Tijuca (22°57.6`S, 43°16.4`W)), P. atrifrons (Bolivia. Santa Cruz: Ichilo, Buena Vista (4-6 km SSE; Hotel Flora y Fauna; 17°29.95`S, 63°33.15`W; 4-500 m)), P. flavicoxalis (West Indies. Dominica. St. David: 1.6 km N of junction of roads to Rosalie and Castle Bruce (15°23.8`N, 61°18.6`W)), P. mcalpineorum (Mexico. Chiapas: Cacahoatan (7 km N; 15°04.1`N, 92°07.4`W)), P. nigrifacies (Brazil. São Paulo: Mogi das Cruzes, Serra do Itapeti (23°31.5`S, 46°11.2`W)), P. obscuripennis (Peru. Madre de Dios: Río Manu, Erika (near Salvación; 12°50.7`S, 71°23.3`W; 550 m)). In addition to external characters, we also describe and illustrate structures of the male terminalia and for P. kotrbae sp. n., the internal female reproductive organs. Detailed locality data and distribution maps for all species are provided. For perspective and to facilitate genus-group and species-group recognition, the family Periscelididae and subfamily Stenomicrinae are diagnosed and for the latter, a key to included genera is provided.