How to Manage Pests
UC Pest Management Guidelines
Pear
Dormant to Delayed-Dormant Sampling
(Reviewed
11/12
, updated
11/12
)
In this Guideline:
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During the dormant to delayed-dormant period, take a
beating tray sample for pear psylla. Also take a shoot sample to examine fruit
spurs (short shoots containing the flower buds) and terminal buds for mites,
psylla, scale, and scab lesions. If mealybugs are a chronic problem in the
orchard, look under the tree bark at the base of the main scaffolds.
Record your observations (example form—).
HOW TO SAMPLE
For orchards less than 20 acres, a smaller sample size may
be taken than indicated below, but adjust the treatment thresholds to your
sample size.
Beating Tray Samples
In
December, monitor overwintering psylla adults with 100 beating tray samples per
20-acre block. Each sample is three taps.
Shoot and spur Samples
Once
during the dormant season (December through early March), collect one shoot
with a fruiting spur from the treetop and one from eye level from each of 50
trees in a 20-acre block, for a total of 100 spurs. (If you sample before February, pear psylla adults may be in the
orchard but not their eggs. Also, pear rust mites become more evident in
February when the buds begin to swell.)
Use a
14 to 20X hand
lens to examine the fruiting spur for:
- European red mite eggs
- Pear psylla eggs
- Pear rust mites
- Pearleaf blister mites
- Predatory mites
Examine
the shoot for:
- San Jose scales
- Pear scab twig lesions
Count the number of spurs or shoots infested with these pests.
Keep records of your results (example form—).
DECISION TABLE
| Sample type |
Pest |
Management decision |
Beating tray
|
Pear psylla |
-
If an
average of two or more adults per 20 beats, treat once according to the Pear
Pest Management Guidelines.
. . . or . . .
-
If more
than 50 adults per 50 beats, treat twice according to the Pear Pest
Management Guidelines.
Resample following treatment to
assess its effectiveness.
|
Shoot and spur
sample
|
Pear psylla |
-
If two
or more dormant spurs have psylla eggs, treat according to the Pear Pest
Management Guidelines.
|
| European red mite |
-
If a
dormant treatment was properly applied and:
- more than 10% of the spurs are infested,
monitor throughout growing season.
- less than 10% of the spurs are infested,
then probably will not be a problem in coming year.
- If no
dormant treatment was applied and three or more spurs are infested in the
sample of 100, monitor throughout growing season.
|
| Pear rust mite |
-
If two
or more shoots are infested, treat according to the Pear Pest Management
Guidelines.
|
| Pearleaf blister mite |
-
If any
mites are present, treat according to the Pear Pest Management Guidelines.
|
| San Jose scale |
-
If a
population of scale has developed in treetops, treat according to the Pear
Pest Management Guidelines.
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| Pear scab lesions |
-
Note
areas of concern for future monitoring.
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Bark sample
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Mealybugs |
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If
mealybugs are a chronic problem, examine under the bark of trees and note
presence for future monitoring.
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IMPORTANT LINKS
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 County
R. B. Elkins, UC Cooperative Extension Lake County
R. A. Van Steenwyk, Insect Biology, UC Berkeley
C. Ingels, UC Cooperative Extension Sacramento County
L. R. Wunderlich, UC Cooperative Extension El Dorado County
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