Treehopper

Treehoppers are a diverse family of true bugs, Membracidae, within the order Hemiptera, renowned among entomologists for the extraordinary variety of shapes formed by their enlarged pronotum, the plate covering the thorax. This structure can be extended into spines, horns, or thorn-like projections that give many species remarkable camouflage on woody plant stems.

As sap-feeding insects, treehoppers use piercing-sucking mouthparts to draw fluids from the stems and twigs of trees and shrubs, and many species have evolved close associations with ants, which tend them for their honeydew secretions in a manner reminiscent of aphid-ant mutualisms.

The family is found worldwide, with especially high diversity in tropical regions, and treehoppers are considered an interesting example of extreme morphological diversification driven by camouflage and, in some hypotheses, sexual selection.

• Small, wedge- or hump-backed body dominated by an enlarged pronotum extending over the abdomen and sometimes the head.
• Pronotum shape varies dramatically by species, resembling thorns, leaves, ant mimics, or elaborate horns.
• Coloration ranges from cryptic browns and greens to more vivid patterns, usually matching the host plant's bark or thorns.
• Piercing-sucking mouthparts positioned beneath the body for feeding on plant stems.
• Lookalikes: often mistaken for actual plant thorns or buds due to their camouflage; distinguished on close inspection by visible legs, antennae, and eyes beneath the pronotum.

Treehoppers occur worldwide, with greatest diversity in tropical and subtropical forests, though many species are common in temperate gardens and woodlands. They are typically found on the stems and twigs of trees, shrubs, and sometimes herbaceous plants, most active and visible during the warmer growing season.

Treehoppers feed by piercing plant stems to withdraw sap, often remaining stationary on the same branch for extended periods, relying on camouflage rather than flight to avoid predators. Many species exhibit maternal care, with females guarding egg masses or nymph clusters against predators. A number of species also form mutualistic relationships with ants, which protect the treehoppers in exchange for honeydew secretions produced during feeding.

Treehoppers undergo incomplete metamorphosis. Eggs are typically inserted into plant tissue or laid in clusters on stems, hatching into nymphs that resemble small, spinier versions of the adult without functional wings. Nymphs pass through several instars, often remaining gregarious on the host plant, before molting into the winged adult form. Depending on species and climate, one or more generations may occur per year, with eggs or adults overwintering depending on the region.