Cabbage-stem flea beetle

P. chrysocephala measures 3.0–4.0 mm in length. It is variably coloured, but most often a dark metallic blue. Like all flea beetles it has large hind femora which it can use to jump. These are orange-red in colour with the hind femora darkened. It is differentiated from other members of the genus through a lack of anterior angles on its pronotum, the punctures on top of the head being as coarse as those on the elytra, and its first front tarsal segment being equal in length to its third.

It is native to the Western Palaearctic, including Macaronesia, Cape Verde and North Africa and has been introduced into Canada.

P. crysocephala can be found in various habitats, depending on the availability of a host plant. It is particularly associated with wild and cultivated members of the plant family Brassicaceae. It has been directly associated with Brassica napus, B. nigra (black mustard), B. oleracea (cabbages, cauliflowers), B. rapa (turnip rape), Nasturtium officinale (watercress), Raphanus sativus (radish), Sinapis alba (white mustard), S. arvensis (wild mustard), and Tropaeolum majus (common nasturtium).

As an arable pest. It is a serious pest of rape in northern Europe. In central parts of Europe it has a cyclic appearance with peaks in populations at intervals of about seven years. In the UK, it is the most important establishment pest of rape, leading to yield losses of up to 20%.