Enhancement of attraction to sex pheromone of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) by structurally unrelated sex pheromone compounds of Conogethes punctiferalis (Guenée) (Lepidoptera: Crambidae)

Abstract

• OFM and C. punctiferalis are sympatric moth species in orchards. • The two moths belong to different families and use completely different pheromone compounds. • Pheromone compounds of C. punctiferalis elicited antennal responses in OFM males. • The interspecific pheromone compounds also enhanced pheromone attraction of OFM. • Field responses suggested additional semiochemicals for pheromone-based control for OFM. Grapholita molesta (Busck) (the oriental fruit moth; OFM) and Conogethes punctiferalis (Guenée) are both fruit and stem borers with overlapping habitats, occurrences, and outbreak cycles. These two species are in different families and they have completely different sex pheromone components. Here, the effects of the sex pheromone components of C. punctiferalis , ( E )-10-hexadecenal ( E 10-16:Ald) and ( Z )-10-hexadecenal ( Z 10-16:Ald) and their mixture, were evaluated on the sexual communication of OFM by examining electrophysiological (EAG) and behavioral responses. We found that a considerably large amount of E 10-16:Ald or Z 10-16:Ald and a tiny amount of OFM pheromone elicited comparable EAG responses in OFM males, indicating the low antennal olfactory sensitivity of OFM males to the heterospecific pheromone compounds. In two different peach orchard parcels, captures of OFM by their pheromone lures baited in delta traps were increased by at least 1.5 times when OFM pheromone lures were combined with lures that contained 1000 μg of either E 10-16:Ald, Z 10-16:Ald or their mixture. In two other pear orchard parcels, both E 10-16:Ald and Z 10-16:Ald increased captures of OFM in Unitraps in a dose-dependent manner with more than a four-fold increase. Therefore, the enhanced attractiveness of OFM lures by the two interspecific pheromones suggests their potential application to improve mass trapping, population monitoring and mating disruption of OFM.