British Insects: the Genera of Ephemeroptera
Imago. The compound eyes distinctly two-lobed (in males), or rounded (in females); upper lobe in the males, turbanate.
Fore-wings with R5 detached basally from R4. The marginal fore-wing veinlets single. Hind-wings present. The hind-wings of the female imagines no more than one fifth the length of the fore-wings. The hind-wing costa with a conspicuous projection. Hind tarsi with 4 moveable segments, or with 2–3 moveable segments (?).
The abdomen with two tails.
Nymph. The outer tails hairy on the inner side only. Gills mostly at the sides of the abdomen; not fringed with filaments on both sides.
Classification. Superfamily Baetoidea. Family Baetidae.
British representation. 2 species; C. luteolum (Small Spurwing or Pale Watery Dun, Small Spurwing male Spinner, and Little Amber female Spinner), and C. pennulatum (Large Spurwing Dun and male Spinner, Large Amber female Spinner).
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. http://delta-intkey.com’.