Carabus violaceus

Carabus violaceus, sometimes called the violet ground beetle, or the rain beetle[1] is a nocturnal species of a beetle, from the family Carabidae.

The violet ground beetle is a non-shiny, black beetle that has violet or indigo edges to its smooth, oval elytra (wing cases) and thorax.

[2] The species can be found throughout Europe, and Japan.

[2] The species can be found in forests, parks, and gardens.

Both adults and larvae feed on slugs, snails, worms and insects (presumably weevils).