The Orthoptera (from the Greek ορθός, orthos = "straight" and πτεрόν, pteron = "wing") are an order of insects with paurometabolous or incomplete metamorphosis, including the grasshoppers, crickets and locusts. Many insects in this order produce sound (known as a "stridulation") by rubbing their wings against each other or their legs, the wings or legs containing rows of corrugated bumps. The tympanum or ear is located in the front tibia in crickets, mole crickets, and katydids. These organisms use vibrations to locate other individuals.
Orthopterans have two pairs of wings; the forewings or tegmina are narrower than the hind wings and hardened at the base. They are held overlapping the abdomen at rest. The hind wing is membranous and held folded fan-like under the forewings when at rest. They have mandibulate mouthparts, large compound eyes, antennae length varies with species. Their saltatorial hind legs are elongated for jumping
Orthopteroid species have a paurometabolous life cycle or gradual metamorphosis. Most grasshoppers lay their eggs in the ground or on vegetation. The eggs hatch and the young nymphs resemble adults but lack wings and at this stage are often called hoppers. Grasshoppers are able to fold their wings, placing them in the group Neoptera. Through successive moults the nymphs develop wings until their final moult into a mature adult with fully developed wings.
The number of moults varies between species; growth is also very variable and may take a few weeks to some months depending on food availability and weather conditions.
