Signs and Symptoms

Symptom DescriptionImages of Symptom

Tree Crown Dieback

Typically, branches throughout the crown are affected. The dieback results from a lesion, usually within one or two whorls of a branch tip, that girdles and kills the affected branch distal to the point of infection. In most cases, growth of the fungus along the branch towards the trunk of the tree does not extend very far, so no further visible damage to the tree is seen (Gordon et al. 2001). Multiple branch end diebacks are caused from repeated infections.

Crown dieback due to pitch canker

Dead and Dying MP from PC   Fish Hook PC (Don Owen)   Los Osos Community Park 1996 (Richard Little)   Morro Bay golf course dying and recovering trees (Richard Little)   MP killed by Bark Beetle (UC)   Nipomo Regional Park first sighting of PC 1987 (Dave Adams)   PC in X-mas tree farm (UC)   PC Pebble Beach (Don Owen)   Pitch Canker Tree (Dave Adams)  

Branch End Dieback

Internal resin soaking of infected branch end. Trees responds to the fungus by producing resin to stop the infection from spreading. This is seen by the amber color of the infected wood (Barrows-Broaddus et al. 1983). Monterey pine exhibiting branch end dieback.

Branch dieback due to PC

Dying and Dead MP Morrow Bay Golf Course (Richard_Little)   close up flagging (Richard_Little)   Early Flagging on MP San Simeon State Beach (Dave Adams)   Flagging due to PC MP   Infected MP Seedling (Dave Adams)   Monterey Pine branch end canker (Dave Adams)   Monterey Pine New Brighton (Dave Adams)   Monterey Pine Pitch Canker Branch Infection   Nipomo Regional Park first sighting of PC 1987(Dave Adams)   PC Moss Landing school(Don Owen)   Pitch Canker Monterey Pine (Dave Adams)   Terminal damage from PC MP   Terminal damage MP   branch end dieback new   MP crown   Tip dieback from PC (Richard Little)

Infected Pine Cones

Resin flow from infection associated with pine cones. The branch has been girdled by the infection, causing the end of the branch to die. Abundant resin flow is seen as the trees response to the fungus. This symptom is very characteristic of pitch canker.

Resin flow from infection associated with pine cones.

Bark removed showing PC infection (Richard Little)

cone infection new   Monterey Pine Seeds (UC)   PC at base of cone Monterey Pine (Dave Adams)   PC in cone area.jpg   PC infection at base of pine cone.jpg  


Note copious resin flow associated with canker. Copious amounts of resin flow from main stem cankers and may run down the trunk for many feet or drip onto the ground. Dried pitch of old infections will be thickened and amber colored.   In some cases trees may suffer top kill due to girdling of the trunk by the cankers, this can result in death of the entire tree.

main stem canker new

Bark removed showing PC symptoms(UC)   Bark removed showing PC(UC)   Basal infection of MP xmas tree(Dave_Adams)   Bole Canker Monterey Pine(Dave_Adams)   Bole Canker MP(Dave_Adams)   Bole Canker(Dave_Adams)   Branch crotch infection with branch removed to show resinous area MP(Dave_Adams)   Close up of PC infection site   Cross section of branch showing resinous wood from PC   large old canker new   Large Bole Canker MP(Richard_Little)   MP and PC root infection(Dave_Adams)   MP Bole sections along canker New Brighton State Beach(Dave_Adams)   MP old bole lesion(Dave_Adams)   old bole canker   PC Root infection(UC)   Pitch canker branch crotch infection MP(Dave_Adams)   Resin soaked MP root from PC(Don_Owen)   surface roots new   Resprouting below canker after branch end has died MP(Dave_Adams)   Upper bole infection Monterey Pine(Dave_Adams)   basal bark removed new   basal resin flow new  

Insect Vectors

Insects are believed to transmit the pitch canker fungus during exploratory feeding on trees. The fungus has been isolated from a number of insects, and the following insects are capable of vectoring the pitch canker pathogen: engraver beetles (Ips spp.), twig beetles (Pityophthorus spp.), cone beetles (Conophthorus radiata), and deathwatch beetles (Ernobius punctulatus). Adult spittlebugs (Aphrophora canadensis) have not been demonstrated to carry the fungus, but their nymphs do create wounds that may become infected if fungal spores are already present on the branch surface.

Frass from Bark Beetles(Don_Owen)

Bark Beetle Galleries(Don_Owen)   Close up of spittle bug(Don_Owen)   Ips infested MP firewood Cambria(Don_Owen)   Ips Mexaicanus attack on MP(Don_Owen)   Ips paraconfucus gallery(Don_Owen)   Pitch Moth attach on MP(Don_Owen)   Pityophthorus galleries in MP New Brighton Beach(Don_Owen)   Red turpentine beetle attack on MP(Don_Owen)   Spittle bug showing the bug(Don_Owen)   Spittle bug spittle mass(Don_Owen)   Spittle from spittle bug on pine cone(UC)   Twig beetle galleries(Don_Owen)  

Time Lapse Photos

Note the disease progress of these trees over a time period. Disease progression can be slow or quick depending on many factors.

Los Osos community park PC(Richard_Little)

Heritage Pine Tree Los Osos Community Park 1994(Richard_Little)   Heritage Pine Tree Los Osos Community Park 1994(Richard_Little)   Heritage Pine Tree Los Osos Community Park 1996(Richard_Little)   Heritage Pine Tree Los Osos Community Park 1996(Richard_Little)   Heritage Pine Tree Los Osos Community Park 1997(Richard_Little)   Heritage Pine Tree Los Osos Community Park 1998(Richard_Little)   Los Osos 7th St 1994(Richard_Little)   Los Osos 7th St 1996(Richard_Little)   Los Osos Before(Richard_Little)   Los Osos After(Richard_Little)  


These are unifected healthy Monterey Pine Trees.

MP Carmel(Don_Owen)

MP in Huckleberry Hill(Don_Owen)   MP on 17 mile drive(Don_Owen)   healthy mont pine