Landscape and Nursery - Japanese Maple Scale

Japanese maple scale is a common pest problem in nurseries and landscapes and can overwhelm plants when in high numbers. The following is an article on the subject.

Photo From the United States National Collection of Scale Insects Photographs Archive, USDA Agricultural Research Service, Bugwood.org

Japanese maple scale is a common problem in nurseries and landscapes. Many trees can be attacked including Zelkova, American holly, Redbud, Stewartia pseudocamellia, Euonumus alatus, Cornus species, Prunus species, Japanese maple, and American red maple. To control Japanese maple scale, Apply 3 % oil to the trunk and branches now. The next opportunity for applying control measures will be when crawlers are active. Last year it was in mid June when Hawthorn ‘Winter King’ was inbloom and when the buds of Asclepias tuberosa and A. syriaca were showing color. The Insect Growth Regulator "Distance" can be applied when the crawlers are active. If high populations have resulted in dead branches on trees prune these out before crawler hatch to reduce the number of scales potentially moving onto other branches and trees.

Modified from an article in the March 30, 2007 edition on the TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers from the University of Maryland Cooperative Extension