Pitch Canker

There is growing concern that the damage from a serious disease of pines spreading throughout California called Pine Pitch Canker could devastate a large number and variety of pine species. The most susceptible species to date appear to be Monterey (Pinus radiata) and Bishop (Pinus muricata) pines.

Fusarium circinatum or pine pitch canker is a fungus that is transmitted by bark, cone and twig beetles whose dispersal may carry the disease to new locations.

Symptoms consist mostly of browning and dieback of branch tips, wilting of new growth, and resin exuding profusely from the site of infection. Trunk cankers appear after adjacent branch death. Current research suggest that infection is primarily through wounds caused by insects known to carry the disease.

The disease can also be carried on seeds of infected trees resulting in developing seedlings that are also infected. Death of trees may result from the effects of the disease itself, from infesting insects in weakened trees, or a combination of both.

No effective chemical or biological control has yet been developed for pitch canker. Management of the disease is therefore limited to minimizing the spread of the disease by pruning infected limbs. This will not stop it, but slow down its spread.
Replacement plantings of non-susceptible species is a good idea. Plan for removal and replacement of trees should they become infected.
Management efforts that may have some effect on minimizing the spread of the disease are:

  • Removal and disposal of all infected trees
  • Sterilization of all pruning tools between trees

Please call or email City Arborist Inc to discuss your tree’s disease and pest control needs.