Publications - Faculty - Recently Submitted Faculty Publications 2008

Stelinski - Journal of Chemical Ecology

Mating Disruption of Citrus Leafminer Mediated by a Non-Competitive Mechanism at a Remarkably Low Pheromone Release Rate

L. L. Stelinski, J. R. Miller, M. E. Rogers

Abstract: The citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is an important worldwide pest of citrus. A season-long investigation was conducted evaluating mating disruption for P. citrella. Highly effective disruption of male P. citrella orientation to pheromone traps (98 %) and reduced flush infestation by larval P. citrella was achieved for 221 days with two deployments of a 3:1 blend of (Z,Z,E)-7,11,13-hexadecatrienal : (Z,Z)-7,11-hexadecadienal at a remarkably low rate of 1.5 g AI / ha per deployment. To gain insight into the mechanism mediating disruption of P. citrella, male moth catch was quantified in replicated plots of citrus treated with varying densities of pheromone dispensers. The densities of septum dispensers compared were: 0 per tree (0 / ha, 0.0 g A. I. / ha); 0.2 per tree (1 every 5th tree or 35 / ha, 0.05 g A. I. / ha); 1 per tree (215 / ha, 0.29 g A. I. / ha); and 5 per tree (1,100 / ha, 1.5 g A. I. / ha). Profile analysis by the mathematical methods of Miller et al. (2006a,b) matched the predictions of non-competitive mating disruption. Behavioral observations of male P. citrella in the field revealed that males did not approach mating disruption dispensers in any of the dispenser density treatments. The current report presents the first set of profile analyses combined with direct behavioral observations consistent with the theoretical predictions of Miller et al. (2006a,b) for a non-competitive mechanism of mating disruption. The results suggest that disruption of P. citrella should be highly effective even at high population densities given the density-independent nature of disruption for this species and the remarkably low rate of pheromone per hectare required for efficacy.