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Monterey Pine Pitch Cancker  Sudden Oak Death Thousands of coast live oak(Quercus agrifolia), tan oak(Lithocarpus densiflorus), madrone(Arbutus menziesii) and black oak(Quercus kelloggii) have been killed by a newly identified species, Phytophthora ramorum, which causes 'sudden oak death'. Sudden Oak Death was first reported in 1995 in central Coastal California. The host list is expected to expand as Dr. David Rizzo, University of California at Davis, and Dr. Matteo Garboletto, University of California at Berkley, continue their investigations. Symptoms and Impact On oaks and tanoak, cankers are formed on the stems. Cankered trees may survive for one to several years, but once crown dieback begins, leaves often turn from green to pale yellow to brown within a few weeks Black or reddish ooze often bleeds from cankers, staining the bark as well as killing the mosses that grow on it. Bleeding ooze may be difficult to see if it dries or has been washed off by rain. Necrotic bark tissues surrounded by black zone lines are present under affected bark. Because these symptoms can also be caused by other Phytophthora species, laboratory tests must be done to confirm pathogen identity. Infected Coast live oaks sometimes gradually lose their leaves and fade out slowly. If bleeding oaks and leaf spots on bay laurel or other symptomatic hosts are adjacent to one another, it is a good indicator that Phytophthora ramorum may be present. However, laboratory confirmation is needed to be sure since there are many other pathogens that cause similar symptoms. A common saprophytic fungus(Hypoxylon thouarsianum), ambrosia beetles(Monarthrum spp), bark beetles (Pseudopityophthorus spp), and other organisms often colonize infected trees. Other Oak Disorders with Similar Symptoms Sudden Oak Death can be confused with many other disorders of oaks. Oaks defoliated by insects may appear dead, but usually leaves reflush later in the season. Canker rots, slime flux, leaf scorch, root diseases, freeze damage, herbicide injury and other ailments may be confused with the disease. Pest Alert, United States Department of Agriculture, Prepared by Susan Frankel USDA FS, Pacific Southwest Region Monterey Pine Pitch Cancker Pine pitch canker is a disease that mainly effects pine trees in central coastal areas of California. It has been found as far north as Mendocino and as far south as San Diego County. Pine pitch canker effects many native pines in California most importantly however is the Monterey pine (Pinus radiata) and in some cases, planted stands of Douglas fir (Pseudotsuga menziesii) Symptoms and Impact Monterey pine pitch canker is a disease which causes die-back of individual branches leading to a decline in the trees over health and vigor and in some cases, premature death. An infected tree would typically show very distinct dieback of the tips of the limbs. This is caused by a lesion located along the limb beyond which the limb can no longer transfer fluids and so consequently the limb dies. The lesion is caused by a fungus called Fusarium circinatum which produces fungal spores. The spores are spread by wind and rain, and also native insects. Insects known to carry the pathogen include bark beetles and twig beetles which feed under the bark of branches and trunks and cone beetles which attack cones. This is considered the primary means of infection to spread. However, disease can be spread by moving of infected nursery stock or timber transportation from logging. The pathogen is known to survive for a long period of time. There is currently no proven method for preventing pitch canker from infecting trees where the fungus is established. However, maintaining your trees such that they can be in their best possible health will lessen the chances of insect infestation, the primary vector for the spread of Monterey Pine Pitch Canker.
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