How to Manage Pests
UC Pest Management Guidelines
European Fruit Lecanium
Scientific name: Parthenolecanium corni
In this Guideline:
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
There is one generation each year in most areas of the state but a partial
second is often seen in the Central Valley.
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.
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.
Fruit lecanium is frequently kept under control by parasites including Aphytis spp., Coccophagus spp., Encarsia
spp., and Metaphycus spp. and
predators including lady
lacewings. If present, ants will interfere with
biological control; note their presence when monitoring.
Biological control and certain oil sprays are organically acceptable
Monitoring and Treatment Decisions
To determine if a dormant or delayed dormant treatment is
warranted, follow sampling and treatment threshold guidelines in DORMANT SHOOT SAMPLING. 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.
|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.
||DORMANT OIL such as:
||DORMANT FLOWABLE EMULSION
||NARROW RANGE OIL (440 or higher)#
||MODE OF ACTION: Contact including smothering and barrier effects.
||COMMENTS: Choose a narrow range oil with a 50% distillation point of 440 or higher for dormant season
use. Always check with your certifier as to which oils are organically acceptable. Oil alone can control moderate populations of soft scales.
UC IPM Pest Management Guidelines: Peach
UC ANR Publication 3454
Insects and Mites
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 County
Acknowledgment for contributions to the Insects and Mites:
R. E. Rice, Kearney Agricultural Center, Parlier
C. Pickel, UC IPM Program, Sutter/Yuba counties
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