Sciomyzidae

Sciomyzidae is a family of true flies commonly known as 'marsh flies' or 'snail-killing flies'. Comprising over 600 species in approximately 66 genera, they are cosmopolitan in distribution but less common in Australasian and Oceanian realms. Adults are small to medium-sized (2–14 mm), slender, and typically dull gray, brown, reddish, or yellow, with hyaline wings often featuring dark spots or patterns. The head is semispherical, and antennae are usually elongate with pubescent aristae.

Their larvae are acephalous (headless) maggots that primarily feed on aquatic or terrestrial mollusks (snails, slugs), earning the "snail-killing" moniker; some species are terrestrial or saprophagous. About one-third are aquatic, making them potential agents for biological control of pest mollusks. The family includes provisional subfamilies like Huttoninidae, Phaeomyiidae, and Tetanoceridae, with ongoing taxonomic debate over groupings like Salticellinae.