The tegmina (sing. tegmen) are the leathery, hardened fore wings in the insect orders Blattodea, Dermaptera, Mantodea and Orthoptera. The tegmina have developed to protect the insect's hind wings during periods of rest. During flight, the tegmina do move with the hind wings (the fore and hind wings move synchronously, as a unit) but the tegmina probably contribute little to the locomotory effort of the insect; the hind wings create the lift.
In Orthoptera, grasshoppers and locusts specifically, the tegmina has a secondary function. To create their distinctive 'songs', the insects rasp a file on their fore femora (front leg) against a similar scraper on their tegmen, and the vibrations from the leg-on-wing movement create the noise.