Scorpionfly

The scorpion tail

The male scorpionfly’s tail is one of the insect world’s most disconcerting features. The last abdominal segments are enlarged and curl upward like a scorpion’s stinger. This structure is entirely harmless — it is the genitalia, used to grasp the female during mating. The resemblance to a scorpion is coincidental and presumably deters some potential predators, though the insect has no venom or sting of any kind.

Stealing from spiders

Scorpionflies are brazen kleptoparasites — they steal prey directly from spider webs. The male identifies a web containing a captured insect, vibrates the threads to simulate a trapped insect, then snatches the prey and retreats before the spider can respond. The stolen insect is then presented to a female as a nuptial gift; the male copulates with the female while she feeds. Males that cannot steal successfully offer a salivary droplet instead — a much less attractive gift.

Ancient lineage

Mecoptera (scorpionflies and their relatives) is one of the oldest winged insect orders, with fossils dating back 250 million years to the Permian. Mecoptera are thought to be ancestral to or closely related to the lineage that gave rise to true flies (Diptera) and fleas. The beak-like rostrum — a unique structure in insects — functions as a combined feeding tube and sensory probe, used to manipulate food.

Woodland scavengers

Scorpionflies contribute to woodland nutrient cycling as scavengers. They locate dead insects, small vertebrate carcasses, and fallen fruit, using their sensitive rostrum to feed. They are also important prey for insectivorous birds, bats, and other invertebrate predators in woodland edge habitats. The larvae live in soil and leaf litter as scavengers, pupating in a soil cell.