image of a Four-Spotted Owlfly
Scientific Name
8 species in North America north of Mexico
Ascalaphidae (owlflies) in the order Neuroptera (antlions, lacewings, and allies)

Owlflies look like dragonflies outfitted with butterfly heads. Dragonfly shaped and sized, they have long, clubbed antennae and large, bulging eyes. Some rest with their abdomens angled away from the perch, making their bodies look like twigs.

You can distinguish the two genera in our area by looking at the eyes: Those in genus Ululodes have a groove or crease in each eye; those in genus Ascaloptynx lack the groove. Then, if you’ve found the latter, you know the species, too, since there’s only one owlfly in that genus in North America, A. appendiculata, a beautiful insect with gold highlights.

The larvae are flattened, oval, segmented, gray, brown, or black insects with a distinct head and a pair of huge caliper-like mandibles that are usually held wide open. They look a lot like antlion larvae, but their bodies have a fringe of tiny finlike extensions along the two sides. Some species glue detritus (sand or other debris) to their backs for camouflage.

Length: to about 2 inches (without appendages); wingspan to about 3 inches; antennae can be about 1 inch long.
Where To Find
image of Owlflies Distribution Map
Adult owlflies are mostly crepuscular (active at dawn and dusk) or nocturnal. Many are attracted to lights at night. Like many other insects, their heyday is in summer. Larvae hatch from eggs laid on twigs but move to the ground, where they hide in leaf litter and other protected places and hunt by sitting quietly with their jaws open, waiting for a hapless prey item to walk by.
Like the dragonflies they resemble (but are unrelated to), owlflies are predators that snatch insects as they fly through the air. The larvae are predators, too, on the ground in leaf litter, using their powerful little jaws to capture insects and other tiny animals.
Life Cycle
Female owlflies lay eggs in a line on twigs of trees. In addition to rounded, fertile eggs, she also lays a batch of smaller, “trophic” eggs nearby. These won’t hatch. They serve as a first meal for her hungry hatchlings and may prevent them from eating each other. They’re sticky and whorl around the stem like a fence, so they might also keep away ants or other predators. The young larvae move to the ground, where they hunt, eat, grow, and molt. They pupate, in a silky cocoon, in leaf litter.

Most people figure that any insect that devours other insects is helpful.

People who appreciate insects just as they are truly enjoy seeing owlflies, which are bizarre, magnificent, harmless creatures not commonly seen.

The family name, Ascalaphidae, comes from Greek mythology, where a fellow called Ascalaphus was a caretaker of the orchard in the Underworld. He witnessed Persephone eating pomegranate seeds while she was abducted by Hades, and he basically snitches on her to the other deities. They were about to release her from the Underworld, but when they find out she had eaten the seeds, they force her to spend about half the year in the Underworld. Her mother, Demeter (goddess of the harvest), was so sad about her daughter's incarceration she made the world be unfruitful each year during the time Persephone was gone. Also, in her anger, Demeter punishes Ascalaphus by burying him under a boulder. Later, when someone releases him from this punishment, Demeter changes Ascalaphus into an owl.

At all life stages, owlflies are predators and therefore help control populations of the insects they prey on.

But their own camouflage and mimicry of twigs, the larvae’s gluing detritus on their backs, and possibly the “fencing” of trophic eggs, remind us that owlflies are preyed upon, too.

Most members of the owlfly family live in tropical regions.

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About Land Invertebrates in Missouri
Invertebrates are animals without backbones, including earthworms, slugs, snails, and arthropods. Arthropods—invertebrates with “jointed legs” — are a group of invertebrates that includes crayfish, shrimp, millipedes, centipedes, mites, spiders, and insects. There may be as many as 10 million species of insects alive on earth today, and they probably constitute more than 90 percent all animal species.