Development and evaluation of an emulsified paraffin wax dispenser for season-long mating disruption of Grapholita molesta in commercial peach orchards.

The University of California at Davis patented the use of emulsified wax to release pheromones for mating disruption. Advantages of these dispensers include low cost, self-adhesion, and biodegradation. We compared the efficacy and practicality of Confuse-OFM, a commercial emulsified wax formulation of oriental fruit moth, Grapiholita molesta (Busck), pheromone with those of Check-Mate OFM-F sprayable pheromone and Isomate-M 100 polyethylene tube dispensers in commercial peach (Prunus spp.) orchards. Efficacy was measured with male captures in pheromone-, virgin female-, and liquid attractant-baited bucket traps as well as by noting injury to shoots and fruit. Two applications of Confuse-OFM were as effective as two applications of CheckMate OFM-F and one application of Isomate-M 100. However, Confuse-OFM was tedious to apply and wasted pheromone with an initially high release rate. We developed a new emulsified wax formulation (Wax Dollops) that maintained release rates above a 5 mg/ha/h threshold twice as long as Confuse-OFM in the laboratory. Field trials confirmed that one application of 3-ml dollops (590 dollops per ha) provided season-long (approximately 15 wk) control equivalent to that of Isomate-M 100 and Confuse-OFM applied as described above. Several applicators were developed for Wax Dollops, including a pneumatic gun that shot dollops >2 m. However, the most efficient method for application was wiping dollops onto tree branches by using a flat-bladed spatula. This research was the basis for a new line of commercial pheromone pest control products equally effective to current commercial formulations but with advantages in cost and flexibility.