CONTROL OF SOME SCALE INSECTS INFESTING COLORADO TREES AND SHRUBS

This circular is issued for the special benefit of nurserymen and those who have trees and shrubbery to protect against a few of the more common scale insects that are found in this State. OYSTER-SHEI.. L SCALE (Lepidosaphes ulmi Linnaeus) The oyster-shell scale or bark louse is one of the most wide-spread and destructive of the scale insects infesting shade and fruit trees. It is a very general feeder, having been recorded as occurring upon about one hundred different plants. We have found it in Colorado in large numbers on ash, poplar, cotton-wood, willow, lilac, elm ~ buckeye and walnut trees, peonies and, in smaller numbers, on other plants