Marsh Flies, Snail-killing Flies

Sciomyzidae

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Diptera
Superfamily: Sciomyzoidea
Family: Sciomyzidae

Pronunciation

How to pronounce Sciomyzidae: //ˌsaɪoʊˈmɪzɪˌdiː//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Pherbellia anitae by the Smithsonian. Used under a CC0 license.

Melina philippii by the Smithsonian. Used under a CC0 license.

Dictya behrmani by the Smithsonian. Used under a CC0 license.

Renocera cressoni by the Smithsonian. Used under a CC0 license.

Summary

Sciomyzidae, commonly known as marsh flies or snail-killing flies, comprise a diverse family of Diptera that prey on or parasitize mollusks during their larval stage. Adults are often found near water bodies and are characterized by their distinctive elongated antennae and marked wings.

Physical Characteristics

Small to medium-sized (5‒10 mm), slender flies with yellowish, brownish, or grayish bodies; antennae extend forward noticeably; wings often spotted or otherwise marked.

Identification Tips

The distinctive feature is the elongated antennae that extend forward. The wings are often spotted or marked, and the bristles on the head and thorax can help in identification.

Habitat

Adults are found around marshes, lakes, ponds, and wooded areas. Larvae typically inhabit aquatic or semi-aquatic environments, preying on mollusks.

Distribution

Found in all biogeographic realms, poorly represented in the Australasian and Oceanian realms.

Diet

Adults drink dew and nectar; larvae are either predatory on or parasitic to freshwater or terrestrial mollusks, particularly slugs and snails.

Life Cycle

Little is known about the complete life cycle; larvae fend for themselves after hatching and can be either aquatic or terrestrial, with some emerging from their hosts as adults.

Reproduction

Females scatter eggs in the habitat of host snails or slugs. Newly hatched larvae attack their hosts immediately.

Ecosystem Role

Larvae play a role as predators or parasites of mollusks, thereby impacting the local populations of these invertebrates.

Evolution

Sciomyzidae belong to the typical flies (Brachycera) of the order Diptera, with taxonomic uncertainties regarding several closely related families and subfamilies.

Misconceptions

Often misidentified due to similarities with other small flies; confusion exists regarding the relationships between several closely related families.