Megamerinidae

Definition

A small family of true flies (Diptera) comprising approximately 11 described species in three genera, characterized by small body size and a distinctive elongated, basally constricted abdomen. The family's phylogenetic placement has been historically unstable, having been assigned to superfamilies Diopsoidea, Nerioidea, and most recently Opomyzoidea, though its evolutionary relationships remain unresolved.

Etymology

From genus Megamerina + -idae (family suffix)

Example

Megamerinidae species such as those in the genus Megamerina can be recognized in the field by their slender, wasp-waisted abdominal profile, though their rarity makes them infrequently encountered in standard dipteran surveys.

Related Terms

• Diptera
• Diopsoidea
• Nerioidea
• Opomyzoidea
• Megamerina
• acalyptrate

Usage Notes

Use of this family name implies recognition of Megamerinidae as a valid family-rank taxon, though specialists note that its superfamily placement remains contentious. The family is sometimes overlooked in regional faunal works due to its low diversity and uncertain higher-level relationships. When encountered in keys to acalyptrate families, the distinctive abdominal constriction serves as the primary diagnostic character.