Objective was to reveal potential synergism and/or improvement in control efficacy of insecticide sprays when using the PE-MEC spray adjuvant targeted against neonate

The larval attractant kairomonc, ethyl (2E. 4Z)-2,4-decadienoate or pear ester (PE), was tested in a Californian walnut orchard for its control efficacy against codling moth larvae, Cydia pomonella (L.) (Lepidoptera: Tortricidae) in a microencapsulated bait spray formulation (PE-MEC) combined with various insecticides (choropyrifos, phosmet, methoxyfenozide and a granulosis virus, Cyd-X). PE-MEC was tank-mixed as an adjuvant with reduced rates of insecticides and applied by a handgun-sprayer to replicate walnut trees in an 8 ha orchard. Results were significant. with PE-MEC adjuvant + insecticide treatments reducing CM harvest damage by 77% (choropyrifos). 85% (phosmet). 54% (methoxyfenozide)and 47% (Cyd-X) below the damage incurred with insecticides alone. Also with the secondary pest, the navel orangeworm, Amyelois transitella (Lepidoptera: Pyralidae), the PE-MEC adjuvant significantly reduced damage levels when combined with the two OP insecticides. The PE kairomone shows promise for improving insecticide efficacy and contributing to both resistance management and new IPM tactics for C. pomonella and the accompanying A. transitella.