Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/19/2007
Publication Date: 11/9/2007
Citation: Landolt, P.J., Suckling, D.M., Judd, G. 2007. Positive Interaction of a Feeding Attractant and a Host Kairomone for Trapping the Codling Moth, Cydia pomonella (L.). Journal of Chemical Ecology 33:2236-2244. Interpretive Summary: New approaches to manage insect pests of apple and pear crops are needed that are safe, effective, and compatible with the environment. Codling moth is the key pest of apple and a primary pest of pear in the western United States. Researchers at the USDA-ARS laboratory in Wapato, Washington, collaborating with scientists with Agriculture Canada, Summerland, British Columbia, and Hort Research, Lincoln, New Zealand, discovered a novel chemical attractant for the codling moth based on the chemistry of over-ripe pear fruit. This chemical attractant is effective as a lure in a trap to capture both male and female codling moths. This information and the availability of this lure provides new avenues of research to develop more powerful monitoring methods, and to develop baits to kill female codling moths in apple and pear orchards.
Technical Abstract: Codling moths are attracted to acetic acid, and to ethyl-(E,Z)-2,4-decadienoate, the pear ester. Acetic acid is a product of microbial fermentation of sugars, and ethyl (E,Z)-decadienoate is an odorant of pear, which is a host of codling moth larvae. Many more male and female codlling moths were attracted, or were captured in traps, when the compounds were presented together, compared with the chemicals tested separately. This enhancement or synergy of attraction occurred in a flight tunnel study and in three field experiments. The field experiments involved three trap designs, and were conducted in Washington, U.S.A. and in Lincoln, South Island, New Zealand. Given that codling moth attractionto acetic acid is thought to be a food finding behaviror, and ethyl-(E,Z)-2,4-decadienoate is a host odorant (pear), the heightened response to the combined blend supports the hypothesis that codling moths orient to ripe pear odor in search of food, and suggests that some of the reported codling moth orientation to the pear ester is a food finding behavior. The discovery of this attraction synergy provides a stronger lure for female codling moths than currently exists with pear ester alone, and has potential for use in managing this pest of pome fruits and walnuts throughout the world.