Definition: Elytra

The leathery forewing of beetles. When at rest, the elytra close over the back and form a case protecting the folded membranous hind wings. In flight, they spread apart. Also refers to the rigid forewing, which has a more or less protective role, of leafhoppers, cockroaches, etc. Fused in certain families, where the adults (imagoes) are apterous and unable to fly.