Identifying (<I>E</I>)-4,8-Dimethyl-1,3,7-Nonatriene Plus Acetic Acid as a New Lure for Male and Female Codling Moth (Lepidoptera: Tortricidae)

Abstract

Laboratory and field studies were conducted to measure the responses of adult codling moth, Cydia pomonella (L.), to several plant volatiles presented alone and in combination with acetic acid. Plant volatiles included ethyl (E,Z)-2,4-decadienoate (pear ester), (E)-β-farnesene, (Z)-3-hexenyl acetate, ± farnesol, and (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT). Male codling moth exhibited upwind behavioral responses to each compound in flight tunnel tests with acetic acid > DMNT > ± farnesol > (Z)-3-hexenyl acetate > pear ester > (E)-β-farnesene. In apple orchards, however, only pear ester was an effective lure when used alone with clear pane traps. Choice tests in a flight tunnel with delta traps baited with DMNT plus acetic acid caught significantly more male and females than unbaited traps and significantly more females than DMNT-baited traps. Combining pear ester or DMNT loaded in septa lures with separate vials containing acetic acid significantly increased both male and female moth catch compared with the plant volatile alone, acetic acid alone, and unbaited pane traps in field trials. Similar results were not obtained with the other three plant volatiles. Septum loadings of 1 and 10 mg with either pear ester or DMNT in combination with acetic acid caught similar numbers of moths in orange delta traps. Sixty to 75% of the moths captured in traps baited with DMNT plus acetic acid were females. Moth catches in traps baited with DMNT plus acetic acid were ≍40% of catches in similar traps baited with pear ester plus acetic acid.