Fact Sheets

Douglas Fir: Aphids

Douglas Fir: Aphids categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2024-07-10 01:15 Giant conifer aphids on pinePhoto by: A.L. Antonelli Biology The aphids that infest Douglas fir are quite large—up to 1⁄5″ long. They may range in color from gray to brownish to dark. The aphids establish large colonies on the twigs […]

Douglas Fir: Coneworms

Douglas Fir: Coneworms categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2023-01-31 12:00 Coneworm larvae on pinePhoto by: K. Grey Biology Coneworms attack Douglas fir by boring into shoot tips or stems, especially around wounds, and feeding on the soft bark tissues. The portion of the branch beyond the injured point may die […]

Douglas Fir: Cooley spruce gall adelgid

Douglas Fir: Cooley spruce gall adelgid categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2024-06-05 10:40 Douglas-fir Cooley spruce gall adelgidsPhoto by: A.L. Antonelli Biology This aphid-like insect feeds on newly growing needles. Adelgids appear as woolly or cottony tufts on the needles, with heavily infested trees appearing “frosted” or flocked. Small purplish […]

Douglas Fir: Douglas fir needle midge

Douglas Fir: Douglas fir needle midge categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2023-01-31 12:00 Douglas-fir needle midgePhoto by: R.S. Byther Biology The tiny white larvae of the Douglas fir needle midge mine the inside of needles, which become yellowed and distorted. Infested needles often have a sharp bend at the injury […]

Douglas Fir: Douglas fir tussock moth

Douglas Fir: Douglas fir tussock moth categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2023-04-12 12:00 Douglas-fir tussock mothPhoto by: R.D. Akre Biology Douglas fir tussock moth larvae start at branch tips at the top of the tree and work down, feeding mainly on the new foliage and causing severe defoliation. They may […]

Douglas Fir: Douglas fir twig weevil

Douglas Fir: Douglas fir twig weevil categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2024-06-05 10:40 Douglas-fir twig weevil on noble firPhoto by: Unknown Biology The Douglas fir twig weevil is a small, wingless, grayish-black beetle with white markings and sometimes pinkish spots. The adult lays eggs in twigs in the summer. The […]

Douglas Fir: Sequoia pitch moth

Douglas Fir: Sequoia pitch moth categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2023-01-31 12:00 Sequoia pitch mothPhoto by: S.J. Collman Biology The larvae of the sequoia pitch moth feed by boring into branches or trunks. At the point where the larva enters the wood, small to large masses of white to pinkish […]

Douglas Fir: Silverspotted tiger moth

Douglas Fir: Silverspotted tiger moth categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2023-04-12 12:00 Douglas-fir silverspotted tiger mothsPhoto by: A.L. Antonelli Biology The caterpillars of the silverspotted tiger moth feed on the needles, often “tenting” branches with dirty-looking webs. Feeding occurs through fall and winter, with webs becoming more noticeable by spring. […]

Douglas Fir: Spruce spider mite

Douglas Fir: Spruce spider mite categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2024-06-05 02:04 Spruce spider mite adultPhoto by: A.L. Antonelli Biology The presence of spruce spider mites is indicated by yellow or bronze stippling beginning near the needle bases. Infestations usually begin on older needles of the lower branches and spread […]

Douglas Fir: Armillaria root rot

Douglas Fir: Armillaria root rot categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals revision date: 2023-01-31 12:00 White fungal mat of Armillaria root rot infecting trunkPhoto by: C.R. Foss Biology Armillaria root rot is a fungal disease transmitted between plants by root contact. Armillaria is often found in newly cleared soils or ones which have […]

Douglas Fir: Laminated root rot

Douglas Fir: Laminated root rot categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals revision date: 2023-01-31 12:00 Staining in wood (James) and wind-thrown tree (Wallis) R.L. James (wood), G.W. Wallis (tree); Bugwood.org Biology Laminated root rot is a fungal disease of conifers throughout the Pacific Northwest. Douglas-fir, grand fir, and mountain hemlock are highly susceptible […]

Douglas Fir: Rhabdocline needle cast

Douglas Fir: Rhabdocline needle cast categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals revision date: 2024-06-05 02:07 Douglas-fir Rhabdocline needle castPhoto by: R.S. Byther Biology The first symptoms of this fungal infection are many tiny yellow spots on the current season’s needles appearing in late summer or fall. By spring, these spots have expanded and […]

Douglas Fir: Rust

Douglas Fir: Rust categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals revision date: 2023-01-31 12:00 Douglas-fir Melampsora rustPhoto by: G.A. Chastanger Biology Rust is a fungal disease infecting the needles of Douglas fir. Wind-blown spores infect the new needles in the spring. Yellow to orange bumps, or pustules, are found on the underside of needles […]

Douglas Fir: Stem cankers

Douglas Fir: Stem cankers categories: Conifers Douglas Fir Diseases Ornamentals revision date: 2023-01-31 12:00 Douglas-fir stem cankerPhoto by: Unknown Biology Stem cankers on Douglas fir are sunken and oval, occurring on branches or new shoots. Each canker is typically centered around a dead twig and can be small or up to 30″ long or more. […]

Douglas Fir: Swiss needle cast

Douglas Fir: Swiss needle cast categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals revision date: 2024-06-05 02:07 Douglas-fir Swiss needle castPhoto by: R.S. Byther Biology This fungal disease causes infected needles to become off-color and mottled yellow or brown. The needles may turn completely brown and are usually dropped prematurely, often in early spring. Infected […]

Douglas Fir: Upper stem canker

Douglas Fir: Upper stem canker categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals revision date: 2024-06-05 02:07 Douglas-fir upper stem cankerPhoto by: R.S. Byther Biology Upper stem cankers are caused by fungi in the soil. Seedling Douglas fir trees are affected, with the tops of infected trees turning yellow. By fall, the tops turn reddish-brown. […]

Douglas Fir: Yellow-green mottle syndrome

Douglas Fir: Yellow-green mottle syndrome categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals revision date: 2024-07-10 01:13 Douglas-fir yellow-green mottle syndromePhoto by: G.A. Chastanger Biology The cause of yellow-green mottle syndrome is unknown but may be genetic. Needles of all ages are affected by yellow-green mottle syndrome. Yellow-green blotches may be small or may cover […]