How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PEST

European fruit lecanium, also known as the brown apricot scale, occurs throughout the Central Valley, but is rarely a problem. The adult female's domed shell is shiny brown, about 0.4 inch in diameter. Eggs are laid in spring and hatch from May to July. The young develop through the remainder of the season and overwinter on twigs and small branches as partly grown crawlers. There is one generation each year.

DAMAGE

The chief injury is the production of honeydew that, in large amounts, can damage leaves and fruit. Sooty mold growing in the honeydew can cause blackened areas on leaves and fruit.

MANAGEMENT

Biological control is frequently effective; if treatment is needed, oil applied during dormancy or delayed dormancy is an effective way to reduce populations of this pest and the least disruptive of natural enemies. Increased populations of this scale may appear when dormant sprays are omitted.

Biological Control
Fruit lecanium is frequently kept under control by parasites including Aphytis spp., Coccophagus spp., Encarsia spp., and Metaphycus spp. and predators including lady beetles and lacewings. If present, ants will interfere with biological control; note their presence when monitoring.

Organically Acceptable Methods
Biological control and oil sprays are organically acceptable methods.

Monitoring and Treatment Decisions
To determine if a dormant or delayed dormant treatment is warranted, follow sampling and treatment threshold guidelines in DORMANT SHOOT SAMPLE. Look for parasitized scale during the summer by lifting up scale covers as well as examining the covers for exit holes. If a large number of scales are parasitized, treatment may not be needed during the following dormant season.

Common name		Amount to Use**
(trade name)		(conc.)	(dilute)
When choosing a pesticide, consider information relating to impact on natural enemies and honey bees, the impact of the timing on beneficials, and environmental impact. Not all registered pesticides are listed. Always read label of product being used.
A.	DORMANT OIL such as:
	DORMANT FLOWABLE EMULSION	6 gal	1–1.5 gal
	NARROW RANGE OIL#	4 gal	1.5 gal
	MODE OF ACTION: Contact including smothering and barrier effects.
	COMMENTS: Oil alone can control moderate populations of soft scales.
	** For dilute applications, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for concentrate applications, use 80-100 gal water/acre, or lower if the label allows.   * Permit required from county agricultural commissioner for purchase or use.   # Acceptable for use on organically grown produce.

PUBLICATION

UC IPM Pest Management Guidelines: Peach
UC ANR Publication 3454
Insects and Mites
C. Pickel, UC IPM Program, Sutter/Yuba counties
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
J. K. Hasey, UC Cooperative Extension, Sutter/Yuba counties
K. R. Day, UC Cooperative Extension, Tulare Co.
Acknowledgment for contributions to the insects and mites section:
R. E. Rice, Kearney Agricultural Center, Parlier

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