Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/16/2000
Publication Date: 12/14/2000
Citation: Knight, A.L. 2000. Monitoring codling moth (Lepidoptera: Tortricidae) with passive interception traps in sex pheromone-treated apple orchards. Journal of Economic Entomology. 93:1744-1751. Interpretive Summary: A new type of passive trapping system that catches moths by intercepting their flight was evaluated for codling moth in orchards treated with sex pheromone. First, I showed that the mating status of female moths captured with these traps is an accurate estimate of the population's mating status within the orchard. Then these traps were used to monitor codling moth populations in 1995 and 1996 in replicated apple plots. Moths caught on these traps were predominately males and the first female moths were caught later than males. The capture of virgin and mated females coincided in 1995 but mated females were captured 14 d after the first virgin females in 1996. The proportion of females that were mated in these sex pheromone- treated orchards was high in both years and generations. In addition, the total number of moths and the number of female moths caught on these traps were significantly correlated with fruit injury for each generation. The proportion of mated female moths caught on these traps in 1997 was lower and females retained more eggs in a sex pheromone-treated apple orchard versus an untreated grove of crabapple trees. This information provides new insight into the effectiveness of using sex pheromones for disrupting mating in codling moth and suggests that mechanisms other than simply the prevention of mating may be important factors in suppressing codling moth populations with this tactic.
Technical Abstract: Codling moth (CM), Cydia pomonella (L.) were monitored with passive interception traps (PI-trap) in apple orchards treated with sex pheromone dispensers. The proportion of mated females recaptured by PI-traps was significantly higher than the proportion released following the release of both sexes. However, no significant difference occurred between the proportion of mated females recaptured and released when only females were released. Replicated nine-tree apple plots situated either on the edge or in the center of pheromone-treated apple orchards were monitored with PI-traps during first moth flight in 1995 and during both flights in 1996. Moths caught on PI-traps were predominately males. The first male moths were captured 7 to 10 d before females during the first flight in both years. Initial capture of virgin and mated females on PI-traps coincided in 1995. Mated females were captured 14 d after the first virgin females in 1996. The mean proportion of females that were mated ranged from 32 to 55% during first flight and 85 to 92% during the second moth flight. Moth catch and fruit injury were significantly higher in the edge versus the center plots. The numbers of total and female moths caught with PI-traps were significantly correlated with fruit injury for each generation. The percentage of female moths caught on PI-traps that were mated was 32% lower and the mean oocyte load of all females was 42% higher in a pheromone-treated apple orchard than in the untreated crabapple grove.