Evidence for spittlebug warning colouration and mimicry between Aphrophorine and Cercopine species in an Andean valley.

Most tropical spittlebugs of the subfamily Cercopinae are large and boldly coloured insects. Species of this group exhibit a strong odour associated with reflex bleeding and are hypothesized to be protected from predation. Evidence for warning colouration is demonstrated by the discovery that females of a black spittlebug with a broad, contrasting orange band across the middle of the wings, belonging to the genus Sphodroscarta, is an exact mimic of Zuata ephippiata, a Cercopine spittlebug from the same Andean valley. The tentatively associated male, S. bimaculata, is black with smaller, white spots. The colour pattern of the female is quite distinct from the patterns of other Sphodroscarta, which are darker insects striped or spotted with white or tan. This genus belongs to subfamily Aphrophorinae, which consists almost universally of dull, cryptically coloured insects that lack the distinct odour of Cercopine spittlebugs. Convergence of these distantly related species on a single striking colour pattern in one valley appears to represent a case of female-limited Batesian mimicry and a demonstration of the power of selection for aposematic colouration to influence the evolution of spittlebug colour patterns.