Beech Scale

Characteristics

Beech scale is a legless, wingless insect, with rudimentary antennae. They are yellow and soft-bodied, egg-shaped or circular, and covered in a white wool-like coating. Beech scale are female only, and produce one new generation of females annually.

Beech scale lay pale yellow eggs in early July in the woolly filaments at the rear of their body. After hatching, young crawlers are dispersed by wind onto host trees. Crawlers will settle on a tree and feed on its sap. Once a crawler begins to feed, it will molt and no longer be able to move. Crawlers overwinter and molt into their adult form the following spring.

Signs & Symptoms

Beech trees that are heavily infested with beech scale are covered in a white mass of wool on the trunk and branches. Beech scale insects damage trees by feeding on the sap below the bark. When several beech scale feed in close proximity to each other, clusters of cells in the tree collapse and stop working.

Beech scale carry a fungus that can enter the bark of the tree while the insect feeds which causes beech bark disease. Trees that are infected with beech bark disease are incurable.

Treatment & Recommendations

Early detection of beech scale and prompt treatment are the most effective ways to protect beech trees. Treatment is about controlling the beech scale and trying to prevent the transmission of the beech bark disease fungus.

Insecticidal soap and horticultural oil sprays can provide effective control of beech scale when crawlers are present.

If you have concerns about beech scale call our office. One of our qualified arborists can meet with you and talk about beech scale.