Large striped flea beetle (striped turnip flea beetle)
Phyllotreta nemorum

Description

3.0 to 3.5 mm long, head and thorax greenish black, elytra black with a large yellow lateral band, femora and tarsi black, tibiae red. It lives on the leaves of brassicas which it scrapes and perforates, particularly in warm and dry weather. In cold or humid weather, it remains hidden under the foliage or in the ground.