Contributions to the knowledge of Turkish Auchenorrhyncha (Homoptera) with a new record, Pentastiridius nanus (Ivanoff, 1885).Abstract : In this study, 1690 adult Auchenorrhyncha specimens that are collected during the field studies in Kızılcahamam (Turkey: Ankara) in Central Anatolia during the months May-September of 1997 are examined. 101 species belonging to 11 families are found to be distributed in the region. Among these, 7 species belong to Cixidae, 5 species to Delphacidae, 1 species to Meenoplidae, 10 species to Cercopidae, 2 species to Membracidae, and 59 species to Cicadellidae. Habitat descriptions of all detected species are presented with which plant they are collected from and collection records of distribution in Turkey. 70 of these examined species are new records for Kızılcahamam, 16 are new records for Ankara and Setapius nanus Ivanoff, 1885 is a new record for Turkey.