Any of the small, slender, often beautifully coloured and marked sap-sucking insects of the large family Cicadellidae. There is a leafhopper species for almost every type of plant. Most are less than 0.5 in. (12 mm) long. Leafhoppers can be serious economic pests. Their feeding may remove sap, destroy chlorophyll, transmit disease, or curl leaves; they also puncture the host plant while laying eggs. Hopperburn is a diseased condition caused by their injection of a toxin into the plant as they feed.