The orthopterans, which include the grasshoppers, catydids and crickets, constitute the second largest order of hemimetabolous insects, i.e. insects with incomplete metamorphosis.

The orthopterans are a very varied group, but two shared characteristics of most species are that the hind leg is developed into a strong jumping leg, and that the insect can produce audible sound by rubbing the legs and/or wings against each other. The order is divided in two suborders: Ensifera, which encompasses crickets, catydids and some smaller groups, and Caelifera, which encompasses grasshoppers (including locusts). All orthopterans are terrestrial, and most feed on plants.