Pear Insects Lab

The Pear Insects Lab’s main project is an evaluation of integrated pear pest management guidelines in commercial orchards. The guidelines were designed to reduce pear psylla problems by conserving natural enemies. Data from Wenatchee pear orchards are shared weekly in Pear Entomology Weekly starting in 2023. A sample issue of the newsletter includes a link to sign up.

Additional resources on this webpage include summaries of Pear IPM Reports on similar projects.

Pear IPM Reports

Reports from all the Western pear-growing regions indicate that integration of chemical and biological control under selective spray programs reduce pear psylla and mite problems. Reduced spraying can lead to increased secondary pests like leafrollers, true bugs, and sawflies.

British Columbia: Edwards 1993. Excerpts: Until four years ago, a typical pest control program in most pear orchards in the Okanagan and Similkameen Valleys was based on up to 14 different sprays … In 1992, the pear pest management program used by the majority of growers in the 41 orchards we monitored, average 6 spray operations for the season … the 1992 crop was the cleanest in 25 years. Over 90% of the growers have now adopted the “soft program.”

Wenatchee Valley: Alway, 2001 (https://treefruitresearch.org/report/the-wenatchee-valley-pear-ipm-project/). Excerpts: Pear psylla populations were higher in the soft blocks in the first year, but declined in subsequent years to levels similar to the conventional blocks … pest control costs averaged $150-200/ac less each year in the soft blocks … Soft programs are more information and management intensive … Taking a longer term perspective, pear growers need to reduce the almost sole reliance upon pesticides … pear psylla have become resistant to a long list of insecticides and there is no reason to think the future will be any different.

Yakima: Peterson, 2001 (http://web.archive.org/web/20010331010948/http://www.wahort.org:80/) Excerpts: Less money was spent on pesticides for insect and mite control in Pear IPM Project cooperator orchards with no increase in pest damage… The principal tactic used by Porject growers to reduce OP use was to utilize pheromone based mating disruption for codling moth, a key pest. By doing so, they were able to increase abundance of natural enemies, which helped control pear psylla, the other major insect pest in pear.

Southern Oregon: VanBuskirk, Hilton, & Westigard, 2002 (https://www.actahort.org/books/596/596_84.htm) Excerpts: The entomology program in southern Oregon has for many years been developing a selective or “soft” program for the suppression of the arthropod pests complexes on pear…The implementation of a soft pesticide program was slow and frustrating until 1991, when pheromone dispensers for codling moth mating disruption received registration in the United States… While avoidance of disruptive materials in the soft program has significantly lessened the problem of pear psylla resurgence, the reduced use of synthetic pesticides requires that greater attention must be paid to non-traditional pear pests. Codling moth damage, when it occurred, was localized and often occurred in orchard borders.

California: Varela and Elkins 2008. (https://www.actahort.org/books/800/800_130.htm) Excerpts: 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. …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.