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| Life Cycle |
| About White Pine Blister Rust (Cronartium Ribicola) |
| History |
White pine blister rust is a fungal pathogen from
Eurasia. The fungus was accidentally transported
to North America around the turn of the 20th
century on shipments of seedlings from Europe.
Canadian foresters interested in restoring clearcut
areas imported seedlings from Europe to replant
with. Unfortunately, instead of restoring forest
resources, the seedlings unleashed a destructive
pathogen into the environment.
White pine blister rust is incurable and it kills
over 90% of all white pines (or five-needle
pines) it infects. The fungus is dispersed by air,
but it relies on secondary hosts of the Ribes or
Castilea species - these include currants,
gooseberries, and indian paintbrush. Wherever
these plants are present, the fungus can spread
and infect white pines.
Since the early 1900s, blister rust has been
spreading steadily south from Canada. Forests in
Canada, Washington, Idaho, Montana and
Oregon - as well as on the East Coast - have been
devastated in its wake. Blister rust is now an
epidemic in California, including in the Lake
Tahoe Basin.
Eurasia. The fungus was accidentally transported
to North America around the turn of the 20th
century on shipments of seedlings from Europe.
Canadian foresters interested in restoring clearcut
areas imported seedlings from Europe to replant
with. Unfortunately, instead of restoring forest
resources, the seedlings unleashed a destructive
pathogen into the environment.
White pine blister rust is incurable and it kills
over 90% of all white pines (or five-needle
pines) it infects. The fungus is dispersed by air,
but it relies on secondary hosts of the Ribes or
Castilea species - these include currants,
gooseberries, and indian paintbrush. Wherever
these plants are present, the fungus can spread
and infect white pines.
Since the early 1900s, blister rust has been
spreading steadily south from Canada. Forests in
Canada, Washington, Idaho, Montana and
Oregon - as well as on the East Coast - have been
devastated in its wake. Blister rust is now an
epidemic in California, including in the Lake
Tahoe Basin.
| The Spread of White Pine Blister Rust |
| Signs of Blister Rust |
Active sporulation.
Called a "flag," the dead,
reddish brown needles on a
single branch indicate
blister rust infection.
reddish brown needles on a
single branch indicate
blister rust infection.
A limb canker.
The life cycle of blister rust is incredibly complex, but a thorough and highly
readable description of the whole process can be found at ForestPathology.org
by clicking here.
readable description of the whole process can be found at ForestPathology.org
by clicking here.
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