Needles Stems/Twigs/Smaller Branches Larger Branches or Trunk Roots and ground line area Buds	FIR - Abies spp. AFFECTING NEEDLES: CONDITION CAUSE New needles being chewed Douglas-fir tussock moth (Orgyia pseudotsugata) or Western spruce budworm (Choristoneura occidentalis) Needles to exterior of tree bleached or brown, developing late winter Winter dessication Various colored spots Needlecast diseases Orange colored pustules on needles Fir broom rust (Melampsorella caryophyllacearum) Brown felt-like material on needles, branches Brown felt blight (Herpotrichia juniperi) Needles being mined White fir needleminer (Epinotia meritana) Aphids on needles Giant conifer aphids (Cinara spp.) AFFECTING TWIGS AND SMALLER BRANCHES: CONDITION CAUSE Large aphids on branches, twigs Giant conifer aphids (Cinara spp.) AFFECTING LARGER BRANCHES OR TRUNK: CONDITION CAUSE Bark beetles Fir engraver (Scolytus ventralis Le Conte) Borers Flatheaded fir borer (Melanophila drummondi) Witches’ brooms on branches, orange to yellow colored pustules on needles Fir broom rust (Melampsorella caryophyllacearum) Large aphids on branches or trunk Giant conifer aphids (Cinara spp.) Fungal fruiting bodies (mushroom, conks) present Stem decay fungi (various species) Open wounds, internal decay, swollen areas in stem Stem decay fungi (various species) AFFECTING ROOTS AND GROUND LINE AREA: CONDITION CAUSE White root decay with white mycelial fans between bark and wood Armillaria root disease (Armillaria mellea) AFFECTING BUDS: CONDITION CAUSE Buds tunneled Western Spruce budworm (Choristoneura occidentalis)
Missoula County Extension Office; Missoula, Montana 59808 - Updated for 2006