SPRAY APPLICATION OF PARAFFIN EMULSIONS CONTAINING INSECT PHEROMONES FOR MATING DISRUPTION

Research was conducted to determine the feasibility of spray application of insect pheromones on the trunk, scaffold limbs, and canopy of trees. The objectives were to develop a sprayable pheromone carrier, a simple spray delivery system, and to evaluate the effectiveness of spray application of pheromones for mating disruption by comparison with commercial plastic dispensers. The carrier developed was a paraffin/pheromone emulsion, thick and stable at ambient temperature, which was applied with a modified grease pump operated by hand. The release rate of oriental fruit moth (OFM) pheromone from emulsions containing 4% pheromone in 59% water and 30% wax was 0.75 mg/day in laboratory tests over 133 days, compared with 0.44 mg/day from commercial plastic dispensers in similar tests. In a mature cling peach orchard, 75% of the emulsion material sprayed was deposited on the tree, either on the foliage or limbs. Field tests in a commercial almond orchard showed that spray applied paraffin/pheromone emulsions were comparable to commercial plastic dispensers at disrupting mating behavior of OFM.