Shigo, A.L. 1964 Organism interactions in the beech bark disease.. Phytopathology 54: 263-269.

Notes: The beech bark disease is a spectacular tree disease caused by the joint actions of a fungus and a scale insect (Cryptococcus fagi). A number of other organisms are closely associated with these two agents and may be more important in the disease cycle than is now realized. The purpose of this paper is to describe briefly several of the other organisms known to be associated with the beech bark disease, to discuss some of their interactions, and to suggest that the disease is further complicated by the actions of a second scale insect (Xylococcus betulae).