Coremacera marginata is a species of fly in the family Sciomyzidae, the marsh flies or snail-killing flies.
Subspecies include:
This species occurs in most of Europe and in the Near East. These flies can be encountered in grasslands and woodlands,
The adults of Coremacera marginata grow up to long. These flies have a slender, dark greyish body. The prominent eyes are reddish. The brown-yellowish antennae are forward-pointing, with a hairy 3rd segment and a whitish arista. The dark grey wings are mottled with greyish spots.
Adults feed on nectar or sipping dew. Larvae prey on several terrestrial genera of snails.