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How to Manage Pests
UC Pest Management Guidelines
Prune
Italian Pear Scale
Scientific name: Epidiaspis leperii
(Reviewed 6/06,
updated 4/09)
In this Guideline:
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Italian pear scale covering is circular, shiny
light gray, and has a brown exuvia slightly off center. The body under the scale covering is dark reddish purple.
The scale is often found under moss and lichen on old prune trees.
This scale inflicts its sucking damage on the wood
of the tree. Heavy populations can cause bark cracking and reduced tree vigor;
however it is usually not a problem.
Light populations of Italian pear scale do not
harm trees; damaging infestations are unusual in California. Insecticide and
oil sprays often have little effect on this scale because a large number of
them overwinter in the adult stage and are concealed in the tree's moss and
lichens. If treatment is necessary, treat during the dormant and delayed
dormant period for most effective control. Registered copper and lime sulfur
sprays directed at moss and lichens on the tree bark will aid in control of
this scale.
Common name |
Amount to Use** |
R.E.I.+ |
(trade name) |
(conc.) |
(dilute) |
(hours) |
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The
following materials are listed in order of usefulness in an IPM program,
taking into account efficacy, impact on natural enemies and honey bees, and impact of the timing on beneficials. When choosing a pesticide, also consider
information relating to environmental impact. Not all registered pesticides are listed. Always read label of product being used. |
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A. |
BORDEAUX# |
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10-10-100 or |
Label rates |
24 |
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FIXED COPPER# |
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COMMENTS:
These treatments are to control the growth of lichens, which provide
protection to the scale. Their removal will aid in the control of the scale.
This is a slow procedure requiring 1 or more years to be effective. Although
the lichens are killed quickly, considerable weathering must occur before
they are removed. Thorough coverage including trunks and limbs is essential.
Not all copper compounds are approved for use in organic production; be sure
to check individual products. For information on creating a Bordeaux
mixture, see UC IPM Pest Note:
Bordeaux Mixture, ANR Publication
7481. |
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B. |
DORMANT OIL such as: |
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DORMANT FLOWABLE EMULSION |
6 gal |
1.5 gal |
4 |
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NARROW RANGE OIL# |
4 gal |
1 gal |
4 |
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MODE OF ACTION: Contact including smothering and barrier effects. |
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COMMENTS:
Oil used alone will only provide partial control. Oil applications at this
time may cause some young shoots to burn or die back, especially in years
when trees are water-stressed, or have recently been subjected to freezing
temperatures or to dry winds. Dormant flowable emulsion is less likely to
cause burn. The Moyer variety is highly susceptible to oil injury; delaying
the oil spray until late Feb.to March 1 will reduce oil burn. Not all oils are organically acceptable; be sure to check individual products. |
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UC IPM Pest Management Guidelines: Prune
UC ANR Publication 3464
Insects and Mites
C. Pickel, UC IPM Program, Sutter/Yuba counties
F. J. A. Niederholzer, UC Cooperative Extension, Sutter/Yuba counties
W. H. Olson, UC Cooperative Extension, Butte County
F. G. Zalom, Entomology, UC Davis
R. P. Buchner, UC Cooperative Extension, Tehama County
W. H. Krueger, UC Cooperative Extension, Glenn County
Acknowledgment for contributions to Insects and Mites:
W. O. Reil, UC Cooperative Extension Solano/Yolo counties
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