Adult spittle bugs exhibit a specialized morphology, having two bullae, or false eyes at the caudal end of the wings which could confuse potential predators as to which way they are facing. Though, it might also just be an inherited trait, and simply a relict leftover from larger and earlier species. -Don McIntire
Spittle bugs are found throughout the US, with about 6 species in California. During the nymph stage, the nymph extracts fluid from the host plant and excretes spittle and air, which flow over the nymph’s body and mix with secretions from the abdomen. The result is a long-lasting bubbly mixture that covers the nymphs. This appears to serve two purposes: it prevents desiccation, and it conceals the nymphs from predators. In the adult stage, the insects are about 1/2″ long and superficially resemble leaf hoppers. While the adult can fly, it usually “hops” about on plants and rests froglike with its head elevated. Because of these features, the adult is often called a froghopper, and in field guides both names are used. Adult coloration is drab, with brownish shades being typical. While local species appear to have no adverse effects on plants in TPSR, large infestations in agricultural areas can cause significant reduction in crop yield. – John Carson
Hogue C.L., Insects of the Los Angeles Basin.
Zim and Cottam: Insects (Golden Guide).
Milne, L. & M.M.: Audubon Guide to North American Insects and Spiders.
Berenbaum: Ninety-nine Gnats, Nits, and Nibblers.
Next example: Yucca Moth