froghopper

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of various plant-feeding insects of the superfamily Cercopoidea, having adults with long legs used for leaping and nymphs that form frothy masses of liquid on plant stems.

from The Century Dictionary.

• noun A homopterous insect of the family Cercopidæ, so called from the general shape of the body and the power of leaping.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any of various small insects of the family Cercopidae that feed on plant sap and whose larvae produce cuckoo spit.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a variety of spittlebug