17d9e magnolia scale
Magnolia Scale on branch

Magnolia Scale is the largest soft shell scale pest found in North America. It is typically the size of a fingernail and has a variety of appearances, depending on the stage of its life. Scale nymphs (young scale) overwinter on one to two year old twigs and emerge in Spring to immediately begin feeding. The appearance of both the male and female scale change during this Spring period. Both turn white with a slightly fuzzy appearance, with the female growing larger than the male. The females will continue to grow during the Summer. Scale colors change slightly as they mature, but the white fuzzy appearance is most recognizable.  Female Magnolia Scale lay eggs on tree branches and the eggs hatch in early Fall. This stage is called crawlers. The crawlers emerge from eggs alive and immediately move around tree branches looking for a suitable place to overwinter. This makes treatment critical during the crawler stage, when the Magnolia Scale is most vulnerable.

Kramer Tree Specialists offers Magnolia Scale treatment in the Fall and Spring. The Fall treatment consists of two applications, starting in mid-September.  This targets the crawler stage, when the Magnolia Scale are most susceptible to pesticide application. Because Magnolia Scale is such a difficult pest to control, it’s recommended that treatment occurs over three consecutive years. This ensures newly hatched crawlers are destroyed and prevent future infestations.

Identifying Magnolia Scale often takes a trained eye, due to the large quantity of Scale species and number of stages in its’ life.  As the pest name indicates, certain trees are more susceptible to Magnolia Scale. Magnolia varieties are very susceptible, as is the Tuliptree. Keep in mind this is not a hard fast rule. Maple trees have also been known to become infested with Magnolia Scale.  Sooty mold, a fungus, often develops on a plant infested with Magnolia Scale. This pest produces a large amount of “honeydew”, which is a sticky substance excreted by the pest. Sooty mold often develops on the honeydew and causes the plant stems to appear blackish. As the sooty mold spreads, it affects the leaves of the plant, which may die prematurely.  

Contact the Plant Health Care department at KTS to discuss the symptoms you’re experiencing or to have a Certified Arborist personally inspect your tree. We offer treatment solutions for the health of your trees and shrubs.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.