Any of some 2,000 species of hopping insects (family Cercopidae, order Homoptera) with whitish nymphs that use a special abdominal valve to aerate an anal fluid secretion. The resulting frothy spittle protects the nymphs from enemies and desiccation. Adults are less than 0.6 in. (1.5 cm) long. The meadow spittlebug (Philaenus leucophthalmus), of Europe and North America, resembles a frog and is a powerful leaper. It feeds extensively on clover and alfalfa, causing severe stunting that can result in the loss of up to 50% of a crop. Some African species occur in such enormous numbers that their spittle drips from tree branches like rain.