2.6-3.5mm. Dark blue metallic elytra but black otherwise. The genus is characterised by having the second antennal segment expanded so it is wider than the third segment. Perapion also have elytral intervals that are quite widely spaced, certainly wider than the striae. P. violaceum has dense, coarse punctures on the metasternal disk and the first two visible sternites.

P. hydrolapathi is similar but with fine, sparce punctures on the metasternal disk and sternites.

Unless identified by a recognised expert, photographic evidence is required and the specimen should be examined with a microscope. In the comments box, state the key or ID method used. Note the beetle's size and describe the identifying characters. It is advisable to retain the specimen in case further checks are needed.

Often found on Dock leaves.

All year but peaking in spring and summer.

Widespread and fairly frequent in England and Wales.

Fairly frequent in Leicestershire and Rutland. There were a total of 21 VC55 records for this species up to March 2015.