Pitch canker kills pines, spreads to new species and regions

Abstract

The host and geographic range of the pitch canker pathogen has greatly increased since it was first discovered in California in 1986. Most significantly, it now affects many pine species, including na- tive stands of Monterey pine, and has made a transgeneric jump to Douglas fir. Isolated occurrences of the disease have been found as far north as Mendocino County. Insects are strongly implicated as vectors of the pathogen, and long- term management appears to be dependent on the development of resistant tree varieties. In infested regions, the planting of Monterey pine and other pine tree species should be undertaken with caution.