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PINE PITCH CANKER

 What is Pitch Canker?
Pitch canker is a recently introduced fungal disease of pines. Monterey and Bishop pines are especially susceptible, although other non-native and native California pines can become infected. If allowed to progress, Pitch Canker will kill the tree. The disease was first reported in California in 1986 in the Santa Cruz and southern Alameda county areas. Currently, the disease is found in 14 coastal and adjacent inland counties from San Diego to Mendocino, including all three native Monterey pine stands in California. Pitch canker also occurs in the southeastern United States from Virginia to Florida and west to Texas, and in Haiti, Mexico, and Japan.

Native insects can become contaminated with the fungus and serve as vectors of the disease. Potential vectors include all twig, cone, and bark beetles associated with Monterey pine. This new relationship between native insects and the introduced pitch canker fungus has already allowed the disease to become well established in planted ornamental Monterey pine, and poses a severe threat to the native Monterey pine stands along California's central coast.

A Threat to Pines
While the condition of Monterey pine along the coast clearly has the potential to worsen, an additional concern is that other native pines in the Coast Range, Cascade Range, and the Sierra Nevada may become diseased. Because of the potential environmental and economic impacts of pitch canker, it is important to limit its spread. Disease spread can occur through transport of infected trees and tree parts, bark beetle insect vectors, and the use of contaminated tools. Seeds from infected trees can give rise to infected seedlings. Infected seedlings may initially appear disease-free, but later develop disease symptoms.

Recognition
Infections of branch tips are typically quite striking (1). The first symptom usually noticed is a color change in the foliage at the ends of branches-these are called "flags." Flagging can be caused by the disease, feeding activity of twig beetles, or a combination of both. Needles on infected branch tips fade from the normal dark green to lime green, to yellow, and finally to sorrel before needle drop. Needle color change can occur any time of the year.


#1

 #1. Branch tip killing by pitch canker disease. A very common early expression of disease presence.
If pitch canker is the cause of the fading, closer inspection of these branch ends will reveal pitch flow at the transition zone between dying and green needles (2). These characteristics may be hard to see if fading branches are high in the tree. The infected wood under the bark is resin-soaked and amber in color (3). The name "pitch canker" is appropriate because infections are characterized by a copious pitchy flow. Cankers may be found on any woody part of the tree including cones, branches, the tree trunk, and exposed, damaged roots. Pitch from large branch or bole infections may run down the trunk for many feet or drip onto the ground (4a). Dried pitch of old infections will be thickened and amber colored (4b). Pitch nodules of the sequoia pitch moth can resemble pitch canker infection. These nodules are usually rounded, but can run down the host for a foot or so. Most have remnants of the insects pupal case extending out as in the illustration (5). Pitch tubes of the red turpentine beetle occur at the base of the trunk as illustrated (6). This bark beetle is not believed to participate in disease spread, although attacks can weaken an already stressed Monterey pine.

A small percentage of Monterey pine appears to be immune to the disease, although the nature of this resistance is poorly under stood. Ips bark beetles contribute to the decline of infected trees and typically kill the most severely infected.

Disease Control
There are some things you can do to prevent disease spread:

Know if you are in a pitch canker infested area.

Know how to recognize pitch canker.

Realize that pine pitch canker can be transported on pruning tools, logs, Christmas trees, seedlings, wood and bark chips, cones, seeds, and wood waste.

Do Not transport infected or contaminated material to areas that are free of the disease (7).


#2

 #2. Pitch canker infection at base of cones. One cone is drying out and opening. Note this is a transition area between dying and green needles.


#3

 #3. Resinsoaked, ambercolored wood of an infected branch.

 
  4a                           4b

 #4. Resin flow down the trunk of an infected Monterey pine. Color of resin varies from light (4a) to amber (4b) with 


#5

 #5. Pitch nodule produced by the sequoia pitch moth. Note the insect's pupal case (arrow) protruding out of the pitch mass. When cutting or pruning a diseased tree, clean tools with a disinfectant before using them on uninfected branches or other trees (8).

*Avoid disease and insect buildup by prompt removal and disposal of dead pine material by either burning,

Cover or enclose plant material when it is taken off your premises to avoid dispersal of contaminated bark beetles.

 

 

 

 

 

 

 

 

 

 

 

 

 

 


#6

 #6 Red turpentine beetle attack (pitch tubes at arrowa) at the base of a Montery Pine


#7

 #7. Pitch canker infection in at the base of a young Monterey pine. Note resin soaking of wood.


#8

 #8. Cleaning apruning tool after making a branch cut.