Blue-eyed black fly, Heesch, the Netherlands

The violet black-legged robber fly, "Dioctria atricapilla", is a species of robber fly in the subfamily Dasypogoninae. This 9- to 12-millimeter long insect has a wingspan of roughly 7 to 9 mm and short, three-segmented antennae. It's a predatory insect, feeding mainly on smaller flies and predatory hymenopterans. It primarily thrives in grassland, and is seen from May to July.