British Insects: the Genera of Ephemeroptera


L. Watson and M. J. Dallwitz

Caenis Stephens

Ordella Campion.

Imago. The compound eyes rounded.

Second antennal segment no more than twice as long as the first. Wings fringed in the imago. Fore-wings with R5 and R4 joined basally. Hind-wings absent. The fore-legs inserted relatively close together under the thorax. Hind tarsi with 4 moveable segments.

The abdomen with three tails.

Nymph. Gills mostly lying on the upper surface of the abdomen; not fringed with filaments on both sides.

Classification. Superfamily Baetoidea. Family Caenidae.

British representation. 5 species; C. horaria, C. luctuosa, C. macrura, C. rivulorum, C. robusta (all the Duns and Spinners colloquially named Angler’s Curse).

Illustrations. • Caenis macroura, Cloeon dipterum, Rhithrogena semicolorata: Stephens VI, 1835.

To view illustrations with legends giving names in current use, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa, as well as source references and other relevant material.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. British insects: the genera of Ephemeroptera. Version: 29th December 2011.’.