Cryptococcus fagisuga, commonly known as the beech scale or woolly beech scale, is a felted scale insect in the superfamily Coccoidea that infests beech trees of the genus Fagus. It is associated with the transmission of beech bark disease because the puncture holes it makes in the bark allow entry of pathogenic fungi which have been identified as Nectria coccinea var. faginata and sometimes Nectria galligena.