Disruption of mating in the spotted tentiform leafminer (Lepidoptera : Gracillariidae) using synthetic sex pheromone

The potential for using synthetic sex pheromone to disrupt mating of spotte d tentiform leafminers, Phyllolnorycter blancardella (F.), was evaluated in four experimental and two commercial apple, Malus domestica (Borkh) (Rosac eae), orchards in Ontario during 1992 and 1993. The average disruption inde x [i.e., (total number of moths trapped in control plot - total number of m oths trapped in pheromone-treated plot) / total number of moths trapped in control plot x 100] was 80.7% when leafminer pheromone, (E)-10-dodecen-1-yl -acetate, was evaporated into square, approximately 400-m(2) plots. During the 2-year study, pheromone was evaporated into the pheromone-treated plots at an average hourly rate of 39.6 mg/ha. There was no relationship between the estimated release rate of pheromone and average temperature. There was a negative linear relationship between the disruption index and leafminer density, as measured by the number of moths trapped in the control plot. Th ere was no relationship between the disruption index and the estimated rele ase rate of pheromone. Our results suggest that it may be possible to contr ol the spotted tentiform leafminer using sex-pheromone-mediated mating disr uption.