Douglas Fir: Aphids Categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals Last review date: 2026-04-26 10:31 Giant conifer aphids on pine Photo 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 […]
Douglas Fir: Coneworms Categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals Last review date: 2025-08-13 08:31 Coneworm larvae on pine Photo 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 […]
Douglas Fir: Cooley spruce gall adelgid Categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals Last review date: 2026-04-27 07:09 Douglas-fir Cooley spruce gall adelgids Photo 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. […]
Douglas Fir: Douglas fir needle midge Categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals Last review date: 2026-04-27 07:20 Douglas-fir needle midge Photo 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 […]
Douglas Fir: Douglas fir tussock moth Categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals Last review date: 2026-04-27 07:53 Douglas-fir tussock moth Photo 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. […]
Douglas Fir: Douglas fir twig weevil Categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals Last review date: 2026-04-27 08:31 Douglas-fir twig weevil on noble fir Photo 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 […]
Douglas Fir: Sequoia pitch moth Categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals Last review date: 2026-04-27 11:23 Sequoia pitch moth Photo 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 […]
Douglas Fir: Silverspotted tiger moth Categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals Last review date: 2026-04-27 11:29 Douglas-fir silverspotted tiger moths Photo 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 […]
Douglas Fir: Spruce spider mite Categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals Last review date: 2026-04-28 08:10 Spruce spider mite adult Photo 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 […]
Douglas Fir: Armillaria root rot Categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals Last review date: 2026-04-26 10:43 White fungal mat of Armillaria root rot infecting trunk Photo 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 […]
Douglas Fir: Laminated root rot Categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals Last review date: 2026-04-27 10:12 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 […]
Douglas Fir: Rhabdocline needle cast Categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals Last review date: 2026-04-27 10:28 Douglas-fir Rhabdocline needle cast Photo 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 […]
Douglas Fir: Rust Categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals Last review date: 2026-04-27 11:09 Douglas-fir Melampsora rust Photo 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 […]
Douglas Fir: Stem cankers Categories: Conifers Douglas Fir Diseases Ornamentals Last review date: 2026-04-28 08:20 Douglas-fir stem canker Photo 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 […]
Douglas Fir: Swiss needle cast Categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals Last review date: 2026-04-28 08:25 Douglas-fir Swiss needle cast Photo 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 […]
Douglas Fir: Upper stem canker Categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals Last review date: 2026-04-28 12:10 Douglas-fir upper stem canker Photo 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 […]
Douglas Fir: Yellow-green mottle syndrome Categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals Last review date: 2026-04-28 12:13 Douglas-fir yellow-green mottle syndrome Photo 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 […]