Around 5mm in length. The elytra have a maroon/purple iridescent sheen and a domed appearance, studded by tiny dimples.

Associated with Perforate St John's Wort (Hypericum perforatum).

Mid to late summer.

The larvae feed during the night on shoot tips and basal and developing leaves of St. John's Wort and the adults feed in clusters during the day on flower buds and terminal leaves. Up to 2,000 eggs are laid on the basal leaves in the autumn and the larvae hatch in spring, feed up and then pupate in soil. The adults emerge in June/July and some overwinter as well as the eggs.

This species is fairly common throughout England with the main concentration of records coming from the south.

It is occasional in Leicestershire and Rutland with most records coming from the east of the region. There were a total of 17 VC55 records for this species up to March 2015.