any of approximately 2,000 species of small (less than 1.5 cm 【0.6 inch】 long), hopping insects (order Homoptera), worldwide in distribution, that produce a frothy substance known as spittle. The whitish nymph secretes a fluid through the anus that is mixed with a secretion from the abdominal glands. Air bubbles are introduced through a special valve on the abdomen to create spittle that protects the larva from enemies and desiccation.

The meadow spittlebug (Philaenus leucophthalmus) is froglike in appearance, has grayish-brown wings and is a powerful leaper. It is found in Europe and North America. Some African species occur in enormous numbers and secrete large amounts of spittle, which drips from tree branches like rain. The sugarcane froghopper (Tomaspis saccharina) is very destructive in Trinidad. Aphrophora species are serious pests of willow and pine. One group of froghoppers secretes small calcareous tubes that resemble snail shells and were once classified as snails by zoologists.

The two-lined spittlebug (Prosapia bicincta) is one of the most common species in eastern North America. Adults are dark brown with two red-orange stripes and feed on grasses, weeds, and holly. Nymphs are yellow and are often found on grasses in late spring.