Owlflies

Definition

A family of neuropteran insects (Ascalaphidae, order Neuroptera) comprising roughly 450 extant species of fast-flying, visually oriented predators. Adults are characterized by large, bulging compound eyes—often divided into separate dorsal and ventral regions—and strongly clubbed or knobbed antennae; they hunt other flying insects during crepuscular or daytime hours. Larvae are elongate, litter-dwelling ambush predators that may cover themselves with debris for camouflage (self-decoration), a behavior convergent with some reduviid bugs and chrysopid larvae.

Etymology

From the large, forward-facing eyes that suggest an owl's face, combined with the general resemblance to true flies (Diptera) in flight habit despite belonging to a different order.

Example

The North American Ululodes quadrimaculatus, a common woodland owlfly, patrols forest edges at dusk, using its divided eyes to track prey against both sky and ground backgrounds simultaneously.

Synonyms

• Ascalaphidae

Related Terms

• Neuroptera
• Lacewings
• Antlions
• antennae
• Compound eyes
• Crepuscular
• ambush predator
• self-decoration camouflage
• larval morphology

Usage Notes

Despite the common name, owlflies are not true flies (order Diptera) but neuropterans closely related to antlions and lacewings. The divided eye structure—rare among insects—allows simultaneous focus on contrasting light environments. Clubbed antennae distinguish adult owlflies from superficially similar dragonflies and from antlions, which have thread-like or slightly clubbed antennae. Larvae are sometimes mistaken for beetle grubs but possess distinctive sickle-shaped, hollow mandibles for impaling prey.