FNZ 25 - Cercopidae (Insecta: Homoptera) - Popular summary
Hamilton, KGA; Morales, CF 1992. Cercopidae (Insecta: Homoptera). Fauna of New Zealand 25, 40 pages.
( ISSN 0111-5383 (print), ; no. 25. ISBN 0-477-02636-2 (print), ). Published 25 May 1992
The Cercopidae are one of the most distinctive families of plant-sucking insects. Adults have a streamlined body with a large, shieldlike plate extending between the wing bases, thus resembling leafhoppers (Cicadellidae). However, their hind legs resemble those of planthoppers (Fulgoroidea), with prominent spurs on the sides and tip of the tibia. Their squat, rather frog-like appearance and ability to jump have given rise to the common name 'froghoppers'.
Cercopid nymphs live inside a foamy, spittle-like mass which they secrete on to the stems, leaves, or root crown of their host plant, and hence lead an essentially aquatic existence. You may be familiar with these spittle masses, which in western Europe have long been known as 'cuckoo spit'. The nymphs generally resemble the adults but lack wings and are paler in colour; both life stages are known as 'spittlebugs'.
Spittlebug nymphs have special adaptations for producing the frothy bubbles within which they are concealed and protected. Part of their intake of plant sap is diverted from the oesophagus to the hind gut, and exudes from the anus. The nymphs breathe by means of a tubelike canal below the abdomen, and air is replenished by thrusting the tip of the abdomen outside the spittle mass. Strong contractions of the abdomen inside the spittle mass eject air from the tubular canal and result in bubble formation.
Spittlebugs have no close relatives, but are distantly related to both leafhoppers and cicadas. They feed on a wide variety of plants, including grasses, herbs, and trees. The meadow spittlebug of the Northern Hemisphere has nearly 400 recorded hosts, although it prefers a much smaller range of mostly herbaceous plants; it is now established and apparently spreading in New Zealand. Native spittlebugs in New Zealand seem to favour woody plants, notably manuka, rata, and Coprosma.
Fifteen species in four genera are recognised from New Zealand, most of them confined to the North Island. Four species on island groups to the north and west (New Caledonia, Norfolk Island, Lord Howe Island) are closely related to New Zealand forms.
The largest of the New Zealand spittlebugs is related to a species from Chile. Their ancestors probably existed before the New Zealand and South American land masses lost their connection over 100 million years ago. Other spittlebug species seem to have been carried here by the strong winds of tropical storms, or more recently through human commerce.