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How to Manage Pests
UC Pest Management Guidelines
Almond
Dormant Spur Sampling and Treatment
Guidelines
(Reviewed 1/05,
updated 1/05)
In this Guideline:
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Dormant spur sampling is used to determine the need for a dormant treatment to
control San Jose scale, European red mite, brown mite and European fruit
lecanium. Spurs are the short shoots containing the flower buds. Dormant spur
samples are taken once a year between mid-November and the end of January.
See sampling forms (PDF* 48K) with
detailed treatment threshold information for dormant spur sampling.
View photos for identification
- Randomly select 35 to 50 trees from each orchard or plot to be sampled.
- Selecting major scaffolds randomly, clip 2 to 3 spurs from the inside of each tree's canopy for a total of 100 spurs.
- Clip the spur off at the base, making sure to include some old spur wood along with the past season's growth to detect parasite activities on scales.
- Using a hand lens or binocular microscope, examine 20 of the spurs for scales and mite eggs, and record observations in a sampling form. It is not necessary to count the number of individual insects or mite eggs present, just identify the pest and record whether it is present or not.
- Note how many scales are parasitized. A parasitized scale can be distinguished from a live scale by a small hole in the top of the scale covering. Parasitized European fruit lecanium scales turn black. If a large number of scales have been parasitized, minimize the use of insecticides during the growing season and only use those that are not harmful to parasites so that naturally occurring populations will not be destroyed.
- If no scale or mite eggs are found in the initial sample of 20 spurs, no more spurs need to be examined.
- If 1 to 3 spurs are infested with scale, examine the next 20 spurs.
- If 4 or more spurs are infested with live scale, apply a treatment.
- Continue examining spurs until a decision is made to treat or not to treat using the treatment guidelines on the sampling form on the online version of this guideline.
Do not combine totals for the two scale species. For example, if 3 spurs out of
a sample of 20 are infested with San Jose scale and 3 spurs contain European
fruit lecanium, neither has exceeded the threshold and sampling should
continue. Treat for brown mite and European red mite if 20% or more spurs are
infested.
Use observations of percent infested spurs to help determine what pesticides to
use following the guidelines below.
Dormant Treatment Decision Table (% Infested Spurs).
| Pest |
Threshold |
Treatment |
| San Jose Scale |
Below 20% |
No Spray |
|---|
| 20 - 60% |
Oil at 6-8 gals/acre |
| Over 60% |
Oil with insect growth regulator2 |
| European Fruit Lecanium |
Below 20% |
No spray |
|---|
| Over 20% |
Oil only |
Overwintering Mite Eggs1
(European red or brown mite)
|
Below 20% |
No spray |
| Over 20% |
Oil only |
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UC IPM Pest Management Guidelines: Almond
UC ANR Publication 3431
General Information
F. G. Zalom, Entomology, UC Davis
C. Pickel, UC IPM Program, UC Cooperative Extension, Sutter/Yuba counties
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
R. L. Coviello, UC Cooperative Extension, Fresno Co
R. A. Van Steenwyk, Insect Biology, UC Berkeley
M. W. Freeman, UC Cooperative Extension, Fresno Co.
Acknowledgment for contributions to the insects and mites section:
R. E. Rice, Kearney Agricultural Center, Parlier
L. C. Hendricks, UC Cooperative Extension, Merced Co.
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