Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2005
Publication Date: 6/1/2005
Citation: Knight, A.L., Light, D.M. 2005. Dose-response of codling moth (Lepidoptera: Tortricidae) to ethyl (E, Z)-2,4-decadienoate in apple orchards treated with sex pheromone dispensers. Environmental Entomology. 34(3):604-609. Interpretive Summary: Monitoring codling moth with sex pheromone-baited traps in orchards treated with sex pheromone mating disruption is often difficult due to the disruption of male orientation to traps. An alternative monitoring program has been suggested following the identification of the pear ester as a potent attractant for both sexes of codling moth. Studies were conducted to evaluate the influence of lure loading of pear ester on the capture rates of male and female moths in apple orchards treated with sex pheromone mating disruption. Our results suggest that the optimal lure loading of pear ester depends on the objectives of monitoring. Lures loaded with > 0.1 mg pear ester caught similar numbers of male moths, however, 40.0 mg lures were most attractive early in the season and would likely be the most effective for determining the start of moth flight. Lures loaded with 3.0 mg pear ester caught the greatest numbers of female moths including significantly more virgin females than other rates tested. Thus this lure would be most useful in developing female moth-based action thresholds, predictive timing models for egg hatch, and control strategies that lure and kill females.
Technical Abstract: Studies were conducted to evaluate the attractiveness of various lure loadings of ethyl (E, Z)-2,4-decadienoate (pear ester) to adult codling moth, Cydia pomonella (L.). All studies were conducted in orchards treated with sex pheromone mating disruption. Lures loaded with 0.1 ' 50.0 and 10.0 ' 50.0 mg caught significantly more male and female moths than the blank control. Field dose-response studies were repeated with five lure rates (0.1 ' 40.0 mg) of pear ester on four dates during the summer. Significant seasonal date and rate effects were found for the capture of males and female moths. The 0.1 mg lure caught significantly fewer males than the 1.0, 3.0 and 40.0 mg lures. The 40.0 mg lure caught significantly fewer female moths than the 1.0 and 3.0 mg lures. The 3.0 mg lure caught a higher proportion of virgin females than the 10.0 and 40.0 mg lures. The attractiveness of the 1.0 and 3.0 mg pear ester loadings were compared with a sex pheromone lure during a 10 wk trial in 2002. Both pear ester lures caught significantly fewer moths than the sex pheromone lure during the first 4 wk of the study and over the entire 10 wk period. However, no difference among lures occurred during wk 5; and the 3.0 mg lure caught significantly more moths than the sex pheromone lure during wk 6. The 3.0 mg lure caught a significantly higher proportion of female moths and a higher proportion of virgin female moths than the 1.0 mg lure. These studies suggest that the optimal loading of pear ester for capture of codling moth in mating disrupted apple orchards likely depends on the specific objectives of the monitoring program.