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Douglas Fir (Pseudotsuga menziesii)

Crown and Needle Symptoms

Symptom

Possible Causes

Reference Photo

Branch flagging with red or yellowing needles over the course of one or two years. Top crown to whole crown death, often in clumps of trees.

Flatheaded fir borer (Phaenops drummondi)

AND/OR

Douglas fir beetle (Dendroctonus pseudotsugae)

FFB crown mortality

Douglas Fir Beetle Crown Mortality. Source: Danny Cluck

Thinning crown with rounded top. Stunted leader, branches, and needles. Needles yellowish green in some cases.

Black stain root disease (Leptographium wageneri var. pseudotsugae)

Black Stain Root Disease Crown Decline. Source: Source: USDA Forest Service

Crown yellowing, often with top-down decline and distress crop.

Armillaria root disease (Armillaria spp.)

 

Massive, drooping witch’s brooms across part or all of the crown, eventually leading to branch and eventually tree death in stressful environments or years.

Douglas-fir dwarf mistletoe (Arceuthobium douglasii)

A. douglasii Crown Damage. Source: Terry Henkel

Branch flagging with red or yellowing needles over the course of one or two years. Top crown to whole crown death, often in small diameter trees experiencing drought or other stressors

Douglas Fir Pole Beetle (Pseudohylesinus nebulosus)

AND/OR

Douglas Fir Engraver Beetle (Scolytus unispinosus)

*see trunk and branch diagnostic table for distinction; management strategies are the same

Douglas Fir Engraver Beetle or Douglas Fir Pole Beetle Crown Damage. Source: WA State Dept of Natural Resources

Douglas Fir Engraver Beetle or Douglas Fir Top Kill. Source: Elizabeth Willhite, USDA Forest Service, Bugwood.org

Reddening of needles and subsequent death of terminal and small lateral branches, especially on smaller trees at the edge of stands

Douglas Fir Twig Weevil (Cylindrocopturus furnissi)

DFTW crown damage

Dieback at the top of the crown, dead, hook-shaped leader in seedlings

Phomopsis canker (Phomopsis lokoyae)

 

Phomopsis lokoyae Branch Damage. Source: Donald Owen, California Department of Forestry and Fire Protection, Bugwood.org

Phomopsis lokoyae Seedling Damage. Source: USDA Forest Service, Bugwood.org

Trunk and Branch Symptoms

Symptom 

Possible Causes

Visual

Missing bark, 1/8 to 1/4 inch, oval-shaped exit holes without boring dust

Flatheaded fir borer (Phaenops drummondi)

Flatheaded Fir Borer Trunk Damage. Source: Donald Owen, California Department of Forestry and Fire Protection, Bugwood.org

Butt swelling on older trees, presence of brown rot in heartwood when cored, presence of velvety, brownish layers of cushion-like fruiting bodies (often referred to as cowpie fungus) at base of tree or on lower trunk

Velvet polypore/Cowpie Fungus/Dyer’s polypore (Phaeolus schweinitzii)

 

Phaeolus schweinitizii Fresh Fruiting Body. Source: American Mycological Association

Phaeolus schweinitizii Old Fruiting Body. Source: James W. Byler, USDA Forest Service, Bugwood.org

Conks with reddish-brown to black tops and golden, irregularly shaped pores below growing out of trunk near branch stubs or old wounds 

AND/OR 

punk knots with reddish brown fungal tissue near branch stubs or old wounds 

AND/OR

Reddish-purple streaks in the heartwood followed by white pocket rot

Red Ring Rot (Porodaedalea pini)

Porodaedalea pini Fruiting Bodies on Trunk. Source: Terry Henkel

Porodaedalea pini Fruiting Body Underside. Source: Terry Henkel

Resin/pitch on trunk, black staining on cross-sections of lower trunk

Black stain root disease (Leptographium wageneri var. pseudotsugae)

Black Stain Root Disease Sapwood Damage. Source: William Jacobi, Colorado State University, Bugwood.org

Black shoestring-like cords and white fans of fungal tissue running up the first few meters of the trunk (under bark), sometimes resin bleeds near base of tree

Armillaria root disease (Armillaria spp.)

Armillaria Fungal Tissue Under Bark. Source: US Forest Service

Round or oval sunken cankers around dead or dying branchlets, sometimes with resin flowing from the canker and/or blackened bark on canker edges; dark pimple-like fruiting bodies may be present on stem

Phomopsis canker (Phomopsis lokoyae)

 

Phomopsis Canker on Trunk. Source: US Forest Service

Swelling on main trunk or on branchlets, sometimes with small pale stems of parasitizing plant sprouting out of the affected area; notably bushier branching structure in branches around the swollen branch.

Douglas-fir dwarf mistletoe (Arceuthobium douglasii)

A. douglasii on Branch. Source: Terry Henkel

Swelling or reddish-brown discoloration on small twigs, branches, or stems, and/or presence of entry and exit holes near dead branches, and/or presence of a mottled bronze and white weevil on outer bark. Larvae in L-shaped chambers in twigs and small branches

Douglas Fir Twig Weevil (Cylindrocopturus furnissi)

Douglas Fir Twig Weevil Larvae in Twig. Source: Mike Jones, UC Cooperative Extension

Exit holes on trunk or branches, larval chambers under bark that are arranged in two branches (one pointing upward and one downward) along a vertical central notch

Douglas Fir Pole Beetle (Pseudohylesinus nebulosus)

Douglas Fir Pole Beetle Gallery. Source: Karen Ripley, WA Dept of Natural Resources

Exit holes on trunk or branches, larval chambers under bark that are arranged continuously along a central notch that has a distinct short chamber coming off one end of the central notch

Douglas Fir Engraver Beetle (Scolytus unispinosus)

Douglas Fir Engraver Beetle Gallery. Source: Wayne Brewer, Auburn University, Bugwood.org

Exit holes with orangish tan boring material, and/or pitching on trunk;

5” - 10” long galleries with alternating groups of larval chambers coming off the central notch

Douglas Fir Beetle (Dendroctonus pseudotsugae)

Orange boring dust from Douglas fir beetles on the trunk of Douglas fir. Source: Christine Buhl, OR Dept of Forestry

Douglas fir beetle gallery, with alternating chambers coming off a main notch. Source: Kenneth E. Gibson, USDA Forest Service, Bugwood.org

Root and Ground-level Symptoms

Symptom

Possible Causes

Visual

Medium to large velvety, brownish (lighter on margins when fresh) layers of cushion-like fruiting bodies at or near base of tree or on lower trunk

Velvet polypore/Dyer’s polypore (Phaeolus schweinitzii)

Phaeolus schweinitizii Fresh Fruiting Body. Source: American Mycological Association

Black staining on cross-sections of roots, small, white reproductive structures 

Black stain root disease (Leptographium wageneri var. pseudotsugae)

Black Stain Root Disease Lower Trunk Damage. Source: Donald Owen, California Department of Forestry and Fire Protection, Bugwood.org

Clusters of tannish mushrooms present at the base or near trees, stringy yellowish to white rot with hard black plates present in the roots and lower bole of downed trees

Armillaria root disease (Armillaria spp.)

Armillaria fruiting bodies. Source: USDA Forest Service