The Douglas fir (Pseudotsuga menziesii) is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three varieties: coast Douglas-fir (P.menziesii var. menziesii), Rocky Mountain Douglas-fir (P.menziesii var. glauca) and Mexican Douglas-fir (P. menziesii var. lindleyana). Despite its common names, it is not a true fir (genus Abies), spruce (genus Picea), or pine (genus Pinus). It is also not a hemlock; the genus name Pseudotsuga means “false hemlock”.
Diseases Affecting Douglas Fir
Diplodia Tip Blight
Diplodia (formerly Sphaeropsis) tip blight is caused by the fungus Diplodia pinea. It is the most common and severe disease of pines in Pennsylvania and attacks trees of all ages. Tips of infected current-year shoots will blight. Needles on these dead tips are usually tan to straw colored, shorter than normal, and typically remain attached.
Affected Species:
Rhabdcline Needle Cast
Douglas-fir is the only known host of Rhabdocline. Rhabdocline needle cast infection occurs around bud break, when buds are opening to expose susceptible immature needles
Affected Species:
Swiss Needle Cast
Like most other fungal diseases, Swiss needle cast favors rainy, moist, and cool weather. Fruiting bodies develop through the stomata.
Affected Species:
Insects Affecting Douglas Fir
Bagworms
Bagworm is a caterpillar that molts into a moth in the adult stage. They are easiest to identify by the bags they construct as they feed. Damage includes needle discoloration and injury.
Affected Species:
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