How to Manage Pests
UC Pest Management Guidelines
European Fruit Lecanium
Scientific name: Parthenolecanium corni
(Reviewed 4/10, updated 4/10, pesticides updated 9/15)
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 grown crawlers. 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 beetles and lacewings. If present, ants will interfere with biological control; note their presence when monitoring.
Monitoring and Treatment Decisions
UC IPM Pest Management Guidelines: Peach
Insects and Mites
J. K. Hasey, UC Cooperative Extension, Sutter and Yuba counties
Acknowledgment for contributions to the Insects and Mites:W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
R. E. Rice, Kearney Agricultural Center, Parlier
C. Pickel, UC IPM Program, Sutter and Yuba counties