SP503-H Beech Scale, A Potential Threat in the Landscape

The beech scale (Cryptococcus fagisuga Lindinger) was first found in the U.S. in Massachusetts and Maine in the 1930s. This European insect feeds on American and European beech by inserting its long, needle-like, piercing-sucking mouthparts (or stylets) through the smooth bark, where the scale remains stationary throughout its life. This persistent feeding can stress the tree, especially during drought conditions, and reduce the overall vigor and quality of beech. However, it is this insect’s association with two species of fungi, Nectria galligena (a native fungus) and Nectria coccinea var. faginata (an introduced European fungus), that can cause mortality of beech. As it feeds, the scale repeatedly removes and reinserts its mouthparts, wounding the tree and providing entry sites for the introduction of these two fungal pathogens.