Monday, April 13, 2009

Landscape - Scale Insects: White Prunicola Scale

This is the eleventh in a series on scale insects in the landscape. This post is on the White Prunicola Scale. Information is from the University of Maryland.

White Prunicola Scale (Pseudaulacaspis prunicola), Family Diaspididae

Plants Damaged: This scale is commonly found on Prunus species but can also be seen on magnolia, ligustrum, rhododendron, forsythia, boxwood, and lilac.

Damage Symptoms: Dieback of twigs and yellowing of foliage

Life Cycle: Crawlers are present in May. A second generation occurs in July and a third in September. Crawlers appear about 2 weeks earlier than white peach scale. Crawlers are out in early May to June. Second generation crawlers are out from mid-July to mid-August. The third generation crawlers are out in September.

Monitoring: Both male and female crawlers are salmon colored.

Control: When crawlers are out, Distance mixed with 1% horticultural oil gives excellent control.

Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.

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