Meadow spittlebug, Philaenus spumarius, can be a pest of a variety of ornamental plants, particularly herbacious perennials and herbs. They are known as spittlebugs because of the odd, frothy, spittle-like substance with which they cover themselves. They are often found in meadows or uncultivated fields. While feeding, the nymphs produce a foamy spittle or froth that protects them from predators and drying out. Spittlebugs have sharp beaks they use to pierce the stems of plants and suck the plant juices. The nymph stage produces the frothy material and remains in this protective substance until developing into the adult stage.
Heavy feeding by spittlebugs can stunt plant growth and commonly causes distortion of the new growth on which they feed. Adults spittlebugs are big jumpers. They make an audible thump when they land.
Sources: University of Illinois Extension & Outreach, Oregon State University Pacific Northwest Nursery IPM
Photos: Cheryl Moorehead, Bugwood.org (adult spittlebugs), John Ghent, Bugwood.org (nymph covered with spittle mass on white pine)