Accepted by H. Song: 2 Feb. 2018; published: 29 Mar. 2018 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2018 Magnolia Press Zootaxa 4402 (3): 575–584 http://www.mapress.com/j/zt/ Article 575 https://doi.org/10.11646/zootaxa.4402.3.10 http://zoobank.org/urn:lsid:zoobank.org:pub:1E9D0C1F-FE06-4D65-B1A4-6605E435A842 First records of Dentridactylinae (Orthoptera: Tridactylidae) from Colombia, with description of two new species of Dentridactylus Günther NATHALIE BAENA-BEJARANO 1,2,3 & SAM W. HEADS 1 1 llinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, 1816 South Oak Street, Cham- paign, Illinois 61820–6960, USA 2 Department of Entomology, University of Illinois at Urbana-Champaign, Morrill Hall, 505 South Goodwin Avenue, Urbana, Illinois 61801–3707, USA 3 Corresponding author. E-mail: ntbaena@gmail.com Abstract Two new species of Dentridactylus Günther (Orthoptera: Tridactylidae) are described and illustrated: Dentridactylus quadratus sp. nov. and Dentridactylus truncatus sp. nov. The new species represent the first record of the subfamily Den- tridactylinae from Colombia and the second record for the Americas. Both come from the south of the country and are readily separated from congeners by their larger body size; D. quadratus sp. nov. is further delimited by the quadrate out- line of the epiproct, and D. truncatus sp. nov. by the epiproct with lateral lobes and lateral margin of epiproct not indented. Keys for the identification of species in the Americas are provided. Key words: Neotropics, South America, Caelifera, Tridactyloidea, pygmy mole crickets Resumen Se describen e ilustran dos nuevas especies de Dentridactylus Günther (Orthoptera: Tridactylidae): Dentridactylus quadratus sp. nov. y Dentridactylus truncatus sp. nov. Las nuevas especies corresponden el primer registro para la subfamilia Dentridactylinae en Colombia y el segundo en América. Ambas especies provienen del sur del país y se diferencian fácilmente de otras especies del género por ser de gran tamaño. Adicionalmente, D. quadratus sp. nov. se reconoce por el contorno cuadrado del epiprocto, y D. truncatus sp. nov. por los lóbulos laterales del epiprocto y la margen lateral del epiprocto sin hendidura. Se proveen claves taxonómicas para la identificación de especies en América. Introduction Pygmy mole crickets of the family Tridactylidae (Orthoptera: Caelifera) are small, highly specialized orthopterans restricted to moist habitats close to water sources such as lakes, ponds, rivers, and streams. They have a cosmopolitan distribution and, like many orthopteran groups, have their greatest diversity in the tropics (Cigliano et al. 2017). Tridactylids exhibit a number of morphological adaptations related to their fossorial and semiaquatic life histories, including modifications of the forelegs for digging (broadened protibiae, often with numerous spurs or spines), and in many species, the presence of metatibial lamellae used in swimming and jumping from the surface of water (Günther, 1994; Burrows and Picker, 2010). While the taxonomy and distribution of tridactylids has been studied extensively by Günther (1978, 1979, 1991, 1995), very little is known of their biology or ecology. Dentridactylinae are a small subfamily comprising only 19 species in five genera (two of which are monotypic genera known from fossils). The subfamily is recognized by the well-developed metatarsus presenting a small but distinct subapical tooth (Günther 1979). This subfamily includes the fossil genera †Burmadactylus Heads, 2009 and †Guntheridactylus Azar & Nel, 2008, in addition to the extant genera Bruntridactylus Günther, 1979,