A Diagnostic Guide for Caliciopsis Canker Disease on North American Conifers

Caliciopsis canker disease (CCD) is caused by multiple Caliciopsis species infecting various North American conifers, with Caliciopsis pinea on eastern and western white pines being the most extensively characterized. Symptoms typically include lower branch flagging, sunken resinous cankers, and bark cracking, with severity influenced by environmental stressors such as drought and stand density. The disease is identifiable by the distinctive eyelash-like mazaedia of the pathogen, but species-level diagnosis requires microscopic or molecular confirmation due to overlapping host ranges. This guide documents updated symptomology for C. pseudotsugae on Douglas-fir, discusses geographical ranges of the disease and provides diagnostic details to support accurate identification and management of CCD across hosts.