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How to Manage Pests

UC Pest Management Guidelines

| More pests | More crops | About guidelines |

Pear

Postharvest Survey

(Reviewed 3/8, updated 3/8)

In this Guideline:

Monitor for pests during the postharvest season. Check fruit left on trees to assess the effectiveness of your codling moth program. Also, take a shoot sample to determine management needs for psylla, mites, and pear scab. Note whether pear slug is present in the orchard.

Record your results (example form—107 KB, PDF).

HOW TO SAMPLE

Fruit Sampling. Collect 300 fruit left on trees after harvest. Examine for stings or deep entries to evaluate the effectiveness of the codling moth program.

Shoot Sampling. Collect one top shoot from 20 trees per 20-acre block. Using a 10 to 14Xhand lens, look at 5 leaves on each shoot (for a total of 100 leaves) for the presence of:

  • Pear psylla eggs and nymphs. Count the number of infested shoots.
  • European red mite. Count the number of European red mites.
  • Pear scab.
  • Pearleaf blister mite. Count the number of shoots with blistered leaves.
  • Twospotted and other webspinning spider mites. Count the number of mites.
  • Pear rust mite. Count the number of infested shoots.
  • Pear slug. Note location of infestation.
DECISION TABLE
Sample type Pest Management decision
fruit sample codling moth If 1 to 2% of the fruit (3 to 6 fruit) are infested, reevaluate your IPM program for the following year and be prepared to treat at first egg hatch of the overwintering generation, according to PMG.
shoot sample pear psylla (nymphs and eggs) If 5 or more top shoots are infested, treat according to PMG.
European red mite If 50 to 200 mites per 100 leaves, treat according to PMG. Use lower thresholds if predators are absent.
pear scab If lesions are found, be prepared to treat in early spring.
webspinning spider mites For Bartlett and Bosc varieties (Asian and other varieties usually have higher thresholds): In early districts only, treat postharvest with oil if more than 50 mites per 100 leaves are present. If both pest and predaceous mites are present in ratio of 10:1, treatment may not be needed.
pear rust mite If 2 or more shoots are infested, treat according to the PMG.
pearleaf blister mite When 3 or more shoots show damage, plan to treat the following spring according to PMG.
pear slug Note localized infestations for future monitoring.

IMPORTANT LINKS

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Pear
UC ANR Publication 3455
General Information
L. G. Varela (Crop Team Leader), UC IPM Program, UC Cooperative Extension Sonoma Co.
R. B. Elkins, UC Cooperative Extension Lake Co.
R. A. Van Steenwyk, Insect Biology, UC Berkeley
C. Ingels, UC Cooperative Extension Sacramento Co.
L. R. Wunderlich, UC Cooperative Extension El Dorado Co.

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Statewide IPM Program, Agriculture and Natural Resources, University of California
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For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See How to manage pests, or in the U.S., contact your local Cooperative Extension office for assistance. /PMG/r603900911.html revised: April 1, 2008. Contact webmaster.