Owl Fly

Libelloides macaronius — the European owl fly — is one of about 430 species in family Ascalaphidae (the owl flies) within order Neuroptera (the lacewings, antlions, and allied groups). Owl flies are NOT true flies (order Diptera) and are NOT true dragonflies (order Odonata) despite the close visual resemblance to both — they are predatory neuropteran insects more closely related to antlions and lacewings. The species is widespread across southern and central Europe, North Africa, and parts of western Asia. The dragonfly resemblance is convergent evolution: owl flies have similar elongated bodies, four large translucent veined wings, and aerial predatory lifestyle as dragonflies — but several anatomical features distinguish them. Owl fly antennae are long and club-tipped (similar to butterfly antennae); dragonfly antennae are short bristle-like. Owl fly compound eyes are dramatically bulging and divided horizontally (the upper and lower halves are functionally distinct); dragonfly eyes are smoothly large and undivided. Owl fly wings rest folded over the back at rest; dragonfly wings are held out flat. The species' common name comes from the enormous bulging compound eyes that resemble owl eyes when viewed straight on. Adults are diurnal aerial predators of flies, mosquitoes, small beetles, and other small flying insects, captured midair using a 'leg basket' similar to dragonflies. Larvae are antlion-like ambush predators with large curved sickle-jaws — they hide in leaf litter and soil and grab passing small insects, injecting digestive saliva and consuming the liquefied prey through the hollow mandibles. Owl flies are wholly beneficial — major predators of pest mosquitoes and other small flying insects.