Saturday, April 4, 2009

Landscape - Scale Insects: Cottony Camellia/Taxus Scale

This is the second in a series on scale insects in the landscape. It is a description of the Azalea bark scale. Information is from the University of Maryland.

Cottony Camellia/Taxus Scale (Pulvinaria floccifera), Family Coccidae

Plants Damaged: Taxus yews, camellia, holly, rhododendron, Japanese maple, English ivy, and mulberry.

Damage Symptoms: Yellowing of foliage and dieback of plant in severe infestations. This soft scale produces large amounts of honeydew on which sooty mold will grow.
Life Cycle: Adult females are oval and yellowish tan. This scale can reproduce quickly with over 1,000 eggs per female. There is one generation a year. Crawlers begin to appear in mid- June. The scale tends to accumulate on the undersides of foliage.

Monitoring: Look for sooty mold and honey dew on the foliage. Examine the undersides of leaves for the white cotton-like sacs.

Control: Wait for eggs to hatch and then treat with the insect growth regulator Distance or oil. Soil injections of imidacloprid (Merit in the landscape, Marathon in nurseries) can be applied in April.

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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