Addition of pear ester enhances disruption of mating by female codling moth (Lepidoptera: Tortricidae) in walnut orchards treated with meso dispensers

Authors: Light, Douglas; GRANT, JOSEPH - University Of California - Cooperative Extension Service; Haff, Ronald - Ron; Knight, Alan

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/2/2016
Publication Date: 2/1/2017
Publication URL: https://handle.nal.usda.gov/10113/5801837
Citation: Light, D.M., Grant, J., Haff, R.P., Knight, A.L. 2017. Addition of pear ester enhances disruption of mating by female codling moth (Lepidoptera: Tortricidae) in walnut orchards treated with meso dispensers. Environmental Entomology. 46(2):319-327.

Interpretive Summary: The success of applying low rates (50 ha-1) of dispensers to achieve disruption of adult communication of codling moth, Cydia pomonella (L)., in walnuts, Juglans regia (L.),was evaluated with several methods. These included cumulative catches of male moths in traps baited with either sex pheromone (Ph), codlemone or a combination of codlemone, pear ester (PE) and acetic acid, and by examining the mating status of females. These data were collected from 2011-2014 in untreated plots and in similar plots treated with Meso dispensers loaded with codlemone (Ph Meso) or codlemone and pear ester (Ph+PE Meso). Male moth captures in both the sex pheromone and combination lure traps were significantly reduced > 88% compared with traps in the untreated plots. A significantly higher proportion of female moths were unmated in plots treated with Ph+PE Meso dispensers than in plots treated with Ph Meso, or left untreated. Also, significantly fewer multiple-mated females were trapped in the Ph+PE Meso-treated plots than in either Ph Meso-treated or untreated plots. These data suggest that the addition of pear ester can effectively improve sex pheromone-based disruption of C. pomonella in walnut orchards. Also, these data suggest that the use of low-density hand-applied dispensers can be an effective and lower-cost approach to manage this pest in the large canopy presented by walnut orchards.

Technical Abstract: The success of applying low rates (50 ha-1) of dispensers to achieve disruption of adult communication of codling moth, Cydia pomonella (L)., in walnuts, Juglans regia (L.),was evaluated with several methods. These included cumulative catches of male moths in traps baited with either sex pheromone (Ph), codlemone, E,E)-8,10-dodecadien-1-ol, or a combination of codlemone, pear ester (PE), ethyl (E,Z)-2,4-decadienoate, and acetic acid, and by examining the mating status of females. These data were collected from 2011-2014 in untreated plots and in similar plots treated with Meso dispensers loaded with codlemone (Ph Meso) or codlemone and pear ester (Ph+PE Meso). Male moth captures in both the sex pheromone and combination lure traps were significantly reduced > 88% compared with traps in the untreated plots. A significantly higher proportion of female moths were unmated in plots treated with Ph+PE Meso dispensers than in plots treated with Ph Meso, or left untreated. Also, significantly fewer multiple-mated females were trapped in the Ph+PE Meso-treated plots than in either Ph Meso-treated or untreated plots. These data suggest that the addition of pear ester can effectively improve sex pheromone-based disruption of C. pomonella in walnut orchards. Also, these data suggest that the use of low-density hand-applied dispensers can be an effective and lower-cost approach to manage this pest in the large canopy presented by walnut orchards.