Olfactory activity of ethyl (E,Z)-2,4-decadienoate on oriental fruit moth adults

The potential attractive effect of pear ester (ethyl (E,Z)-2,4-decadienoate) on adult Cydia molesta (Busck) (Lepidoptera: Tortricidae) was investigated. The electroantennographic (EAG) responses of C. molesta to pear ester were recorded, and dose-response curves were calculated. The attractivity of different dosages was assessed in laboratory bioassays in a dual-choice olfactometric arena. The response of virgin males and females to pear ester in the presence and absence of pear, peach, and apple (Pyrus communis L., Prunus persica (L.) Batsch., and Malus x domestica Borkh.; Rosaceae) shoots was evaluated. EAG recordings demonstrated that both male and female C. molesta were able to detect the pear ester. In our bioassay, pear ester readily attracted males, whereas very few females were attracted to it. The response of males was dose-dependent and males preferred pear ester over apple and pear shoot volatiles, while no apparent preference was observed between pear ester and peach shoot volatiles. Therefore, this kairomonal compound could be more effective in attracting the oriental fruit moth when applied in orchards of secondary host plants, like apple or pear, than in peach orchards.