The larval stages of these insects lurk underground, hollow venomous jaws ready to kill anything that falls within range. But their adults are delicate flying insects that look nothing like their young. Would you be able to identify an Antlion?
Common names: Antlions or doodlebugs (US)
Scientific name(s): Family Myrmeleontidae, in the Order Neuroptera (Lacewings)
Antlion larvae have hunched, hairy, bulbous bodies, and flattened heads with long curved jaws often almost as long as the body. Most species are under 1 cm long. Adults are usually mottled grey, poor flying insects with long narrow bodies, long wings, and antennae bent at the tip like a hockey stick. They may have up to a 15 cm wingspan and are huge compared to their larvae because they have exceptionally thin and delicate exoskeletons.
Geographic distribution: Some 2000 species found worldwide, most often in areas with dry sandy soils. They are found in most areas of Australia.
Habitat: Most antlion larvae excavate conical traps in dry sand, and wait under the sand at the bottom of the pit for any small invertebrates to blunder in. They will flick sand at the prey to ensure it falls within reach of the hollow jaws, injecting them with venom and digestive enzymes, and dragging them backwards under the surface. Some species lurk in leaf litter or build a long trench instead of a conical pit, and one species in Japan simply waits motionless on a rock for prey to walk past. Many trap-building species will leave a long meandering groove in dry sand as they move around seeking an ideal spot to excavate their pit. This trail gives rise to the doodlebug name in the US.
Adult Antlions may feed on pollen or small insects but are not very long-lived.
Pest status: Not considered a pest, despite the venom and sharp jaws. Some species may attach their globular sand-covered pupal cases to the wall of a house.
Treatment: No treatment required. Unfortunately, since they are so common at the bottom of building walls, it can be impossible to carry out a general pest spray or install a chemical barrier around the perimeter without killing any antlions present.
Daniel Heald, Technician and Entomologist
Image rights: Daniel Heald