Diopsidae

Definition

A family of true flies (order Diptera) distinguished by the unique synapomorphy of laterally projecting eyestalks that bear both the compound eyes and the antennae at their distal ends—a configuration absent in all other Diptera, where antennae arise medially from the head capsule. The stalked condition is universal in the subfamily Diopsinae and sexually dimorphic (males typically with longer stalks), whereas the subfamily Centrioncinae retains unstalked, conventional eye placement.

Etymology

Example

Males of the African diopsid *Teleopsis dalmanni* compete for lekking territories where females assess eyestalk span as an indicator of condition; experimental manipulation of stalk length directly affects mating success.

Synonyms

• Stalk-eyed flies

Related Terms

• Diptera
• eyestalk
• Sexual dimorphism
• Diopsinae
• Centrioncinae
• Drosophilidae
• Platystomatidae

Usage Notes

The stalk-eyed condition convergently evolved in several dipteran families (Drosophilidae, Platystomatidae, Richardiidae, Tephritidae), but only Diopsidae positions the antennae on the stalk itself—this is the definitive field character. The family is most diverse in the Old World tropics and subtropics.