Reidentification of pheromone composition of Sparganothis sulfureana (Clemens) and evidence of geographic variation in male responses from two US states

GC-EAD analyses of pheromone gland extracts of calling female Sparganothis sulfureana revealed at least 6 compounds that consistently elicited antennal responses from male antennae. In addition to the major pheromone compound, (E)-11-tetradecenyl acetate (E11–14:OAc), which was previously reported, the other compounds were found to be (E)-9-dodecenyl acetate (E9–12:OAc), (Z)-9-dodecenyl acetate (Z9–12:OAc), (Z)-9-tetradecenyl acetate (Z9–14:OAc), (Z)-11-tetradecenyl acetate (Z11–14:OAc), and (E)-11-tetradecenol (E11–14:OH). Tetradecyl acetate, hexadecyl acetate and hexadecenyl acetates were also present in the extracts, but elicited no EAG response from male antennae. Wind tunnel tests demonstrated that males from New Jersey responded equally well to a blend containing five pheromone components in relative to the pheromone glands of calling females. Different male-response profiles from field-trapping tests conducted in the states of Wisconsin and New Jersey were observed, respectively. Significantly higher numbers of male S. sulfureana were caught in New Jersey in traps baited with the binary blend of E11–14:OAc (30 μg) with 1% of Z11–14:OAc, but males from Wisconsin responded equally well to traps containing blends of E11–14:OAc with 0–10% of Z11–14:OAc. The addition of more than 10% of Z11–14:OAc to the primary pheromone compound reduced male captures significantly in both states. Male catches were doubled by adding E9–12:OAc and E11–14:OH to the most attractive binary blend in both states. The trapping test with caged live virgin female moths showed that males in Wisconsin preferred females from the local population than those from New Jersey. The differences in male responses observed may indicate the existence of pheromone polymorphism in this species.