Phaedon Latreille, 1829
Warchalowski (2003) lists 9 European species contained within four sub genera. Of these, four occur in the U.K.; P. tumidulus in the subgenus Paraphaedon Sharp, 1910 and the others within Phaedon s.str.
Within the limited U.K. fauna the genus is easily separated from our leaf beetles by the following characteristics: short-oval and convex species not exceeding five millimetres in length. Dark coloured, usually with a strong metallic reflection. Humeral callus more or less distinct and impressed, at least to some extent, on the inner side. Elytra with regularly punctured striae. Inner margin of the elytral apices without a fringe of cilia. Elytral epipleura weakly angled below the horizontal, and delimited from the elytral flanks by a distinct edge or ridge. Anterior coxal cavities open posteriorly. Hind tibiae smooth in outline and not dilated.Third tarsal segment deeply emarginated. Claws smooth.
Our U.K. species can be identified from the following key:
Pronotum very finely punctured over the middle. Very common species.
Pronotum much more strongly punctured.
Underside of the two basal antennal segments pale, at least in part. Widespread and generally common species.
Antennae entirely dark metallic.
© Lech Borowiec http://www.cassidae.uni.wroc.pl/Colpolon/index.htm
Humeral callus weak and weakly impressed inside. Elytra strongly shining, green or blue with purple, golden or violet reflection. Last abdominal sternite dark. Apex of adeagus broad and evenly rounded. Coastal, scarce and very local, on saltmarsh vegetation.
Humeral callus stronger, impression on inner side deeper. Elytra blue-black, not so shiny. Last abdominal sternite broadly yellow around apical margin. Adeagus not smoothly rounded; weakly produced at apex. Widespread and generally common species.