Published online by Cambridge University Press: 31 May 2012
Williamson (1802) described the white fly Ephoron leukon. From his description of the insect and its habits, recent workers have been able to identify the species correctly. Hagen (1863) suggested that Baetis alba Say is a synonym of E. leukon Williamson. Eaton (1871, p. 124) was undecided as to the identity of E. leukon. In 1883 (p. 47), however, he indicated that leukon is a synonym of albus Say, which he considered to be a member of the genus Polymitarcys. This genus he had erected in 1868, employing Ephemera virgo Oliver as the genotype.