A Comparison of Gray Halo-butyl Elastomer and Red Rubber Septa to Monitor Codling Moth (Lepidoptera: Tortricidae) in Sex Pheromone-Treated Orchards

Abstract

The emission rate, isomeric stability, and relative attractiveness of field-aged gray halo-butyl elastomer and red rubber septa loaded with 4.0 and 10.0 mg of (E,E)-8, I O-dodecadien-l-ol (E8,E10-12:0H, codlemone), the major sex pheromone component for codling moth, Cydia pomonella L., were evaluated. Initially, field-aged red septa loaded with 10.0 mg had significantly higher emission rates than gray septa loaded with 4.0 mg codlemone. Emission rates of codlemone decayed over time from both lures and were similar for lures aged 28-42 d in the field. Isomerization of E8,E10-12:0H occurred rapidly in red septa but did not occur in the gray septa. Moth capture in traps baited with either lure type aged in the field did not differ initially (0 and 7 d), but were significantly lower in traps baited with 14, 28, and 42 d-old red versus gray septa. Significant differences observed in the attractiveness of these two types of field-aged lures were primarily due to changes in their isomeric purity and not to differences in their emission rate. Increasing the codlemone load of gray septa up to 20.0 mg did not improve the performance of lures in sex pheromone-treated orchards. All lures were effective for 10 wk. Loading gray septa with 50.0 mg codlemone increased lure attractiveness and extended its longevity to 16 wk. Proprietary gray septa loaded with a high rate of pheromone and replaced once per season were more attractive than the standard 10.0 mg loaded red septa replaced three times in a sex pheromone-treated orchard.

Keywords: Cydia pomonella; codling moth; sex pheromone; monitoring; lures