Distribution extension of Oriental mayfly Clypeocaenis oligosetosa Soldán, 1983 (Ephemeroptera: Caenidae)

Abstract

Abstract. Clypeocaenis Soldán, 1978 consists of 7 species, 3 of them are known from the Oriental region. Clypeocaenis oligosetosa Soldán, 1983 was described from Vietnam and until now was known only from 2 localities within this country. We found C. oligosetosa in Thailand for the first time. This record significantly extends the known distribution of the species. The main distinguishing characters of the larvae of C. oligosetosa are illustrated. We observed a few small morphological differences between Thai specimens, investigated paratypes of C. oligosetosa and its original description.