OSU Extension Catalog

Before bud break:

• Reddish-brown spots on upper surface of current-year needles; distinct border between diseased area and healthy green tissue
• Swollen, elongated, light-tan fruiting bodies on the underside of symptomatic needles

During bud break:

• Fruiting bodies rupture underside of needle, releasing a mass of spores.

• Douglas-fir sources from east of the Cascades

• Cooley spruce gall adelgid
• Swiss needle cast
• Douglas-fir needle midge
• Rust

• Search for symptoms prior to bud break, in late winter or very early spring.
• Look for reddish-brown splotches on the upper needle surface. Only the newly emerging spring growth can become infected.

• At bud break, spray fungicide (if needed) to prevent infection.
• Remove and destroy severely infected trees prior to bud break.
• Plant resistant or tolerant tree varieties; avoid Douglas-fir from Rocky Mountain seed sources, unless tested.