How to Manage Pests

UC Pest Management Guidelines

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.

Use the sampling form (PDF) with detailed treatment threshold information for dormant spur sampling.

HOW TO SAMPLE

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.

TREATMENT THRESHOLDS

• 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.

IMPORTANT LINKS

• Dormant spur sampling form for San Jose scale, European fruit lecanium, and mites (PDF),
• Photos of pests monitored with the dormant spur sample

PUBLICATION

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
D. R. Haviland, UC IPM Program, UC Cooperative Extension, Kern County
R. A. Van Steenwyk, Insect Biology, UC Berkeley
Acknowledgment for contributions to Insects and Mites:
R. E. Rice, Kearney Agricultural Center, Parlier
L. C. Hendricks, UC Cooperative Extension, Merced County
R. L. Coviello, UC Cooperative Extension, Fresno County
M. W. Freeman, UC Cooperative Extension, Fresno County

Top of page

PDF: You need a PDF reader, such as Acrobat Reader version 8 or later, to view or print this PDF. If no reader is installed on your computer, you can download a free copy of Adobe Acrobat Reader.