Ephoron debaratana sp. nov., A New Species of Burrowing Mayfly (Ephemeroptera: Polymitarcyidae) from Thailand

A new species of burrowing mayfly, Ephoron debaratana sp. nov., is described based on the larval stage. The morphological characteristics distinguished the new species from other known Ephoron species are the followings: 1) pigmented lateral tracheal branches on the abdominal gills, 2) number of tubercles on the tusk, and 3) triangular frontal process. The morphological evidence presented in this study is strongly supported by cytochrome c oxidase subunit I (COI) gene data. This new species was found in a headwater stream in Kanchanaburi Province, Thailand. The habitat information and a comparison to the known species of Thai larvae are also presented.