Conversion from use of organophosphate insecticides to codling moth mating disruption in California pear orchards.
Beginning in 1996, pear growers in California made a rapid transition from organophosphate insecticides to a mating disruption-based codling moth (Cydia pomonella) control program. In the former program, there were three or more applications of organophosphate per year for the control of codling moth. The latter program relies on applying codling moth pheromone dispensers (hand-applied dispensers or aerosol puffers) and selective insecticides to supplement mating disruption when needed. The reduction in use of broad-spectrum insecticides resulted in a decrease of pear psylla (Cacopsylla pyricola) and two-spotted spider mites (Tetranychus urticae) populations with a decrease in pesticide use for these pests. However, there have been sporadic increases of the following secondary pests: oblique-banded leafroller (Choristoneura rosaceana), western boxelder bug (Boisea rubrolienata), consperse sting bugs (Euschistus conspersus), pear rust mite (Epitrimerus pyri), pear sawfly (Caliroea cerasi), and katydids (Phaneroptera nana and Scuderria furcata). We detailed the shift in insecticide use for the ten years of the program. Operating costs for each of the ten years studied in orchards under the mating disruption program declined compared to the conventional insecticide program. Savings were minimal during the first two years of transitioning into mating disruption program, but became significant beginning in the third year. From the third year on, savings were $247 to $511/ha per year. Fluctuations in savings were due to variability in insecticide applications for psylla, mites, and secondary pests.