What insect order is commonly called the twisted-wing parasites?

The insect order commonly called the twisted-wing parasites is Strepsiptera.

Strepsipterans are obligate endoparasites of other insects. Their hosts include bees, wasps, leafhoppers, cockroaches, and silverfish. Many females remain largely inside the host, while adult males emerge as free-living insects to find mates. This radically different lifestyle produces one of the most extreme examples of sexual dimorphism among insects.

The name Strepsiptera comes from Greek roots meaning “twisted” or “turning” and “wing.” Adult males have unusual fan-shaped hind wings, reduced forewings that function as balancing structures, and distinctive raspberry-like eyes. Their small, mobile larvae seek out hosts, enter them, and develop through a complex life cycle.

The group is sometimes confused with flies because of its common name, but Strepsiptera is a separate insect order. Its evolutionary position has historically been debated, especially its relationship to beetles, and modern molecular and anatomical work continues to refine its classification. The parasites’ rarity in collections also partly reflects their concealed lives inside hosts.