Wednesday, May 9, 2007

Euonymus Scale

Earlier this week I had someone bring in a sample of Euonymus Scale. I am sure that there are others who have the same problem. I hope this article from North Carolina Insect Notes will help provide you with the information you need to control this pest.

Euonymus scale is a common and sometimes very damaging armored scale pest of euonymus and a few other ornamental plants. It is found throughout North Carolina wherever euonymus, pachysandra and celastrus grow. Yellow spots first appear on the leaves. Leaves and stems may become encrusted with the scales to such an extent that whole branches or the entire plant may die.

This scale usually has two or three generations per year. The females lay eggs under their protective shell, and the tiny crawlers hatch and emerge from the mother's armor in April, May and June, which means they are active any time now. They crawl along the leaves and stems before inserting their microscopic, threadlike mouthparts and settling down to grow and secrete the armor. Another brood hatches in late summer, and a partial third brood may appear even later so that all stages of development are present during most of the year. Although this scale is small, infestations are often plainly visible particularly with dense populations in which males usually greatly outnumber female scales. We usually recommend the use of oil for euonymus scale suppression as these pesticides should also control spider mites and other pests of euonymus as well. Commercial operations have additional choices such as Safari. In severe and recurring cases, consider removing the plant from the landscape. Choose another plant or one less susceptible. Ornamental and Turf Insect Information Note No. 15 on the euonymus scale gives some information about its control and links to plant alternatives. It is available on the web at:

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