New Mayfly species discovery by CMU scientists: second discovery in genus Ephoron in six decades

29 June 2021

Faculty of Science

Ephoron ookaewae Techakijvej & Phalaraksh, 2021
Order: Ephemeroptera (Mayflies) Family: Polymitarcyidae

Mayflies are delicate insects commonly found near good quality water sources. A new species, Ephoron ookaewae, was discovered by Asst. Prof. Dr. Chitchol Phalaraksh, head of the Department of Biology, Faculty of Science, Chiang Mai University, and his team. This mayfly species was found at the end of the Ping River, in Mueang district of Nakhon Sawan province.

The specific epithet ‘ookaewae’ is a tribute to Assoc. Prof. Dr. Aukaew Prakobvitayakit, a pioneer of the Department of Biology at CMU who taught Dr. Chitchol about aquatic ecosystems and aquatic insects.

Ephoron ookaewae is in the genus Ephoron, of which 14 species have been discovered worldwide. In Thailand, only one species had been reported since 1961, so this is only the second time that an insect from this genus was found in Thailand, 60 years after the first discovery.

The recently discovered species has distinct characteristics from others in that the larvae have 5 to 7 tubercles on the mandibular tusks and they use the tusks to burrow into the dense soil mixed with gravels in areas that have a considerably rapid water flow. They feed on organic sediments and they rear to maturity in groups for reproductive purposes. Mature Ephoron ookaewae have a life span of one to two days.

Mayflies can serve as an indicator of moderate to excellent water quality, and this discovery at the end of the Ping River came to the researchers as a surprise, as it happened during the exploration of water sources in the urban area encompassing the community area. The discovery of a new species is a testament to biodiversity and the abundance of river-end areas, proving that they should be conserved and restored to sustain biodiversity in Thailand.