Pitch Canker Task Force – Signs & Symptoms

Signs & Symptoms

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

Pitch-Canker-Tree(Dave_Adams)

PC-Pebble-Beach(Don_Owen)

PC-in-X-mas-tree-farm(UC)

Nipomo-Regional-Park-first-sighting-of-PC-1987(Dave_Adams)

MP-killed-by-Bark-Beetle(UC)

Morro-Bay-golf-course-dying-and-recovering-trees(Richard_Little)

Los-Osos-Community-Park-1996(Richard_Little)

Fish-Hook-PC(Don_Owen)

Dead-and-Dying-MP-from-PC

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

Terminal-damage-from-PC-MP

Pitch-Canker-Monterey-Pine(Dave_Adams)

PC-Moss-Landing-school(Don_Owen)

Nipomo-Regional-Park-first-sighting-of-PC-1987(Dave_Adams)

Monterey-Pine-Pitch-Canker-Branch-Infection

Monterey-Pine-New-Brighton(Dave_Adams)

Monterey-Pine-branch-end-canker(Dave_Adams)

Flagging-due-to-PC-MP

Early-Flagging-on-MP-San-Simeon-State-Beach(Dave_Adams)

Dying-and-Dead-MP-Morrow-Bay-Golf-Course(Richard_Little)

Close-up-flagging(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)

PC-infection-at-base-of-pine-cone

PC-in-cone-area

cone_infection_new

Cankers

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(UC)

Upper-bole-infection-Monterey-Pine(Dave_Adams)

surface_roots_new

Resprouting-below-canker-after-branch-end-has-died-MP(Dave_Adams)

Resin-soaked-MP-root-from-PC(Don_Owen)

Pitch-canker-branch-crotch-infection-MP(Dave_Adams)

PC-Root-infection(UC)

old-bole-canker

MP-old-bole-lesion(Dave_Adams)

MP-Bole-sections-along-canker-New-Brighton-State-Beach(Dave_Adams)

MP-and-PC-root-infection(Dave_Adams)

Large-Bole-Canker-MP(Richard_Little)

large_old_canker_new

Cross-section-of-branch-showing-resinous-wood-from-PC

Close-up-of-PC-infection-site

Branch-crotch-infection-with-branch-removed-to-show-resinous-area-MP(Dave_Adams)

Bole-Canker-MP(Dave_Adams)

Bole-Canker-Monterey-Pine(Dave_Adams)

Bole-Canker(Dave_Adams)

Basal-infection-of-MP-xmas-tree(Dave_Adams)

basal_resin_flow_new

basal_bark_removed_new

Bark-removed-showing-PC-symptoms(UC)

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.