This site provides information about common diseases and insect pests affecting major SW Oregon tree species, both native and ornamental. Please note that many of the links below take you to other websites.
Host tree identification is important to accurate diagnosis. Many insect and disease problems are host-specific, i.e., they affect one or a few closely related species, and not others. Know your host! If you need help with tree identification, OSU's Trees of the Pacific Northwest website is a great place to start.
General information about tree care & health
Blue spruce
Aphids
Spider mites
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Incense cedar
Broom rust
Abiotic factors – interactions with insects
Cedar bark beetles
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Douglas-fir
Flatheaded fir borer
Douglas-fir insect pests
Phomopsis canker
Douglas-fir twig weevil
Abiotic factors/drought
Diagnosis table
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Leyland cypress
Cedar bark beetles
Cankers & branch dieback
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Madrone
Cankers
Leaf spots/blight
Overwatering/summer watering
Fall webworm
Diseases & insect pests of Pacific madrone
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Maples
Verticillium wilt
Tar spot
Leaf scorch
Tip/branch dieback
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Oaks
Armillaria root disease
Overwatering/summer watering
Defoliators
Galls
Mistletoe
Field Guide to Diseases & Insects of California Oaks
Diagnosis table
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Pines
Bark beetles:
Mountain pine beetle
Western pine beetle
California fivespined ips
Red turpentine beetle
Needle casts: lophodermella, lophodermium, dothistroma, elytroderma
Western gall rust
Pine tip blight
Sequoia pitch moth
Blister rust
Diagnosis table
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Sycamores
Anthracnose
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General information on tree care and health
Abiotic/site factors that affect tree health
Decay fungi associated with oaks & other hardwoods
Fertilization, mulching, & other cultural tip
Insects in firewood
Overwatering/summer watering
Pruning landscape trees
Selecting, planting, and caring for a new tree
Thinning for tree vigor & health
Tree protection on construction & development sites
Water management in landscape trees
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Websites for additional information
Pests in Gardens and Landscapes-Ornamental Trees and Shrubs (UC Davis)
Forest Pest Notes (Oregon Department of Forestry)
Western Forest Insects & Diseases-publications and links
OSU Extension Forest Health Publications (OSU Extension Service)
OSU Plant Clinic-Diagnostic Facility (fee)
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