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Field guide to exotic pests and diseases: Western gall rust
Endocronartium harknessii (J. P. Moore) Y. Hiratsuka
Branch and stem galls on lodgepole pine
Source: Eric Allen, Canadian Forest Service
Source: Eric Allen, Canadian Forest Service
Distribution: Canada, USA, Northern Mexico
Hosts: restricted to pines.
Signs: include formation of spherical, sometimes irregularly shaped and deeply fissured galls usually between 5-10cm diameter on branches and stems of trees. Masses of orange-yellow spores produced from galls on diseased trees; irregular, rounded to pear-shaped swellings appears on host trees 1-2 years after infection.
Likely pathway: seeds, nursery stock, lumber and wood packaging material including dunnage.
Potential impact: severe infection causes death of seedlings and saplings, shoot death and stem malformation in older trees that can cause stem breakage.