treehopper, any member of a cosmopolitan family of winged insects, remarkable for their curious shapes. The shapes are due to the enlargement of the dorsal (upper) covering of the first thoracic section (the region behind the head), which may project upward in a hump or extend forward over the head and backward over the body, and may be ornamented with variously shaped projections. Many treehoppers resemble small thorns and are protectively colored in green or brown. In other species, especially in the tropics, the shapes are quite complex and bizarre. Both larval and adult treehoppers feed on plant juices. The adults, usually under 1/2 in. (1.2 cm) long, jump from one place to another. Females lay their eggs in slits in bark, which sometimes damages the tree; however, few species are important pests. The buffalo treehoppers, genus Stictocephala, common in the United States, causes stunting of fruit trees. Treehoppers are classified in the phylum Arthropoda, class Insecta, order Homoptera, family Membracidae.