Coremacera marginata
In Holland and in Britain this is the most common Snail Killing Fly. There are a few similar species, but they can be told apart quite easily. Coremacera marginata has red eyes. The wings are black with a lot of grey spots scattered around. The thorax has small, unobtrusive markings only. The fly measures some 7 to 10 millimeters. The adults are seen from June to September.
Coremacera marginata is also commercially used for killing snails. The females do not look for snails to lay the eggs on, they simply drop them on the ground. When the weather is favorable, which mains quite wet, the larvae will hunt down the snails themselves.
