Male-specific epicuticular compounds of the sulfur butterfly Colias erate poliographus (Lepidoptera: Pieridae)
Male wing compounds involved in maintaining reproductive isolation between the sulfur butterfliesColias eurytheme andC. philodice have been identified. MaleC. philodice produce threen-hexyl esters; myristate, palmitate, and stearate, which are absent inC. eurytheme. A branched hydrocarbon, 13-methylheptacosane, is found on the wings of maleC. eurytheme, but notC. philodice. Several straight-chain hydrocarbons are on the wings of both species. The esters and 13-methylheptacosane have significant electrophysiological activity. Preliminary behavioral experiments indicate that the esters (especiallyn-hexyl myristate) function as species-recognition signals. The esters and 13-methylheptacosane also have low-to-moderate aphrodisiac activity.