A planthopper is any insect in the infraorder Fulgoromorpha, in the suborder Auchenorrhyncha, a group exceeding 12,500 described species worldwide. The name comes from their remarkable resemblance to leaves and other plants of their environment and that they often "hop" for quick transportation in a similar way to that of grasshoppers. However, planthoppers generally walk very slowly. Distributed worldwide, all members of this group are plant-feeders, though few are considered pests. The infraorder contains only a single superfamily, Fulgoroidea. Fulgoroids are most reliably distinguished from the other Auchenorrhyncha by two features; the bifurcate ("Y"-shaped) anal vein in the forewing, and the thickened, three-segmented antennae, with a generally round or egg-shaped second segment (pedicel) that bears a fine filamentous arista. Overview Planthoppers are laterally flattened and hold their broad wings vertically, in a tent-like fashion, concealing the sides of the body and part of the legs. Nymphs of many fulgoroids produce wax from special glands on the abdominal terga and other parts of the body. These are hydrophobic and help conceal the insects. Adult females of many families also produce wax which may be used to protect eggs. Fulgoroid nymphs also possess a biological gear mechanism at the base of the hind legs, which keeps the legs in synchrony when the insects jump. The gears, not present in the adults, were known for decades before the recent description of their function. Planthoppers are often vectors for plant diseases, especially phytoplasmas which live in the phloem of plants and can be transmitted by planthoppers when feeding. A number of extinct members of Fulgoroidea are known from the fossil record, such as the Lutetian-age Emiliana from the Green River Formation (Eocene) in Colorado. Both planthopper adults and nymphs feed by sucking sap from plants; in so doing, the nymphs produce copious quantities of honeydew, on which sooty mould often grows. One species considered to be a pest is Haplaxius crudus, which is a vector for lethal yellowing, a palm disease that nearly killed off the Jamaican Tall coconut variety. Classification As mentioned under Auchenorrhyncha, some authors use the name Archaeorrhyncha as a replacement for the Fulgoromorpha. The extant families of Fulgoroidea are: Acanaloniidae Achilidae Achilixiidae Caliscelidae Cixiidae Delphacidae Derbidae Dictyopharidae Eurybrachidae (= Eurybrachyidae) Flatidae Fulgoridae Gengidae Hypochthonellidae Issidae (sometimes includes Caliscelidae) Kinnaridae Lophopidae Meenoplidae Nogodinidae Ricaniidae Tettigometridae Tropiduchidae Extinct families include: †Dorytocidae Emeljanov and Shcherbakov 2018, monotypic, Burmese amber, Cenomanian †Fulgoridiidae Handlirsch 1939