3 to 4 mm. Elongate oval and metallic blue in colour. Humeral calli are distinct (bulges at the front of the pronotum). The antennae are black except for the underside of the first two segments which are yellow/orange.

Found around most wetland areas, but also in other habitats. They feed on a variety of plants, but generally on brassicas, garlic mustard etc.

Peak time is June and July but adults are found throughout the year, during the winter under debris, loose bark and deep within grass tussocks, especially near water.

Larvae feed on various cress and mustard species.

Fairly common and widely distributed throughout Britain although records are scattered north of southern Scotland.

Fairly frequent in Leicestershire and Rutland. There were a total of 86 VC55 records for this species up to March 2015.