Cicadas are insects in the order Hemiptera, suborder Auchenorrhyncha (which was formerly included in the now invalid suborder called "Homoptera"). Cicadas are in the superfamily Cicadoidea. Their eyes are prominent, though not especially large, and set wide apart on the anterior lateral corners of the frons. The wings are well-developed, with conspicuous veins; in some species the wing membranes are wholly transparent, whereas in many others the proximal parts of the wings are clouded or opaque and some have no significantly clear areas on their wings at all. About 2,500 species of cicada have been described, and many remain to be described. Cicadas live in temperate-to-tropical climates where they are among the most-widely recognized of all insects, mainly due to their large size and unique sound. Cicadas are often colloquially called locusts, although they are unrelated to true locusts, which are various species of swarming grasshopper. Cicadas are related to leafhoppers and spittlebugs. Cicadas can cause damage to several cultivated crops, shrubs, and trees, mainly in the form of scarring left on tree branches while the females lay their eggs deep in branches.