Ephoron Williamson, 1802

Techakijvej, Chotiwut, Sareein, Nattawut, Hwang, Jeong Mi, Bae, Yeon Jae & Phalaraksh, Chitchol, 2021, A new species of Ephoron Williamson, 1802 (Ephemeroptera: Polymitarcyidae) from Thailand, Zootaxa 4985 (3), pp. 392-402 : 393-394

Genus Ephoron Williamson, 1802

Ephoron Williamson, 1802: 71 [Type species: Ephoron leukon Williamson, 1802 ].

Polymitarcys Eaton, 1868: 84 [Type species: Ephemera virgo Olivier, 1791 ]; synonymized by Spieth (1940).

Eopolymitarcys Tshemova, 1934: 240 [Type species: Eopolymitarcys nigridorsum Tshemova, 1934 ]; synonymized by Edmunds and Traver (1954).

Diagnosis. The adults present wings whitish and hyaline, hindwings are well-developed with numerous cross veins and intercalaries. Forewings with a strong convex vein running parallel to CuP, attached to CuA. Hindwings have a blunt costal projection. In males, hindwings have a long intercalary vein between RA and RS (autapomorphy) ( Kluge 2004). Forelegs of males are developed, whereas mid- and hind legs are poorly developed. Male forceps with 4 segments, caudal filament is reduced. In females, all legs are poorly developed, one caudal filament and two cerci.

The larvae of Ephoron have mandibles with long mandibular tusks covered with numerous tubercles. Tusks curve inwards near apex, easily visible from dorsal view. From lateral view, tusks curve downward. In some species ( E. shigae and E. limnobium ), tusks curve upwards at apex. Head has median frontal process. Forelegs have strong tubercles, specialized for burrowing. Midlegs are small and hindlegs are strong. Abdomen has gills on segments 1–7, gills 1 single and small, 2–7 forked with lateral margin fringed.

Remarks. The larvae and adult characteristic of Ephoron are well described by Ishiwata (1996), based on Japanese species, and Bauernfeind & Soldán (2013) for European fauna.