The new sp. is described from Peru (holotype S: Madre de Dios Dept., Pakitza Reserved Zone, palm swamp at stake 28, near Troncal Castanal, 11° 56’ S, 71° 18'W., 6-VII-I993; allotype 5: Pakitza Reserved Zone, T2 SI9, 11° 56’ S, 71° 18'W„ 8-IX-1989; held in trust at National Museum of Natural History, Washington, D.C. pending repatriation per agreement with the Ministerio de Agriculture, Institute Nacional de Recursos Naturales, Peru) and compared with similar spp. The holotype of T. fluviatilis St. Quentin, 1960 is found to be a junior synonym of T. demararum (Williamson, 1917).