| AFFECTING NEEDLES: |
|
CONDITION
|
CAUSE
|
 |
New
needles being chewed |
Douglas-fir tussock moth
(Orgyia pseudotsugata) or Western spruce
budworm (Choristoneura occidentalis)
|
|
Needles
chewed and fragments tied with webbing |
Spruce needleminer (Endothernia
albolineana)
|
|
Brown
felt-like material on needles, branches (high elevation) |
Brown felt blight (Herpotrichia
juniperi) or Snow mold
|
|
Needles
being mined |
Spruce needleminer (Endothenia
albolineana)
|
|
Aphids
on needles |
Giant conifer aphids (Cinara
spp.)
|
|
Needles
become grayish, with small flecks |
Spruce spider mite (Oligonychus
ununguis)
|
|
White
scales on needles |
Pine needle scale (Chionaspis
pinifoliae)
|
|
Brown
needles with dark fruiting bodies |
Needlecasts (Lophodermium
sp. and others)
|
|
Needles
to exterior of tree bleached or brown, developing late winter |
Winter dessication
|
|
Needles
on branch turn reddish brown |
Cytospora canker (Valsa
spp., Leucostoma spp.) or Root injury
|
|
Mottled
yellowing of needles on a branch |
Winter exposure injury
|
|
| AFFECTING TWIGS AND SMALLER BRANCHES: |
|
CONDITION
|
CAUSE
|
|
Twigs
distorted into cone-like gall |
Cooley spruce
gall adelgid (Adelges cooleyi)
|
|
Woolly
aphid on underside of twigs in spring |
Cooley spruce
gall adelgid (Adelges cooleyi)
|
|
Small
bud-like scales on twigs |
Spruce bud scale
|
|
Large
aphids on branch |
Giant conifer aphids (Cinara
spp.)
|
|
Resinous
canker on branch |
Cytospora canker (Valsa
spp., Leucostoma spp.)
|
|
| AFFECTING LARGER BRANCHES OR TRUNK: |
|
CONDITION
|
CAUSE
|
|
Bark
beetles |
Spruce beetle (Dendroctonus
rufipennis) or Spruce
ips (Ips hunteri Swaine)
|
|
Aphids |
Giant conifer aphids (Cinara
spp.)
|
|
Open
wounds, internal decay, swollen areas in stem |
Stem decay fungi (Phellinus
pini, Inonotus circinatus, Fomitopsis pinocola and
various fungal genera)
|
|
Fungal
fruiting bodies (mushrooms, conks) present |
Stem decay fungi (Phellinus
pini, Inonotus circinatus, Fomitopsis pinocola and
various fungal genera)
|
|
| AFFECTING TOP OF TREE: |
|
CONDITION
|
CAUSE
|
|
Wilting
and dieback restricted to terminal, shepherds’ crook |
White pine weevil (Pissodes
strobi)
|
|
Upper
crown defoliated |
Douglas-fir tussock moth
(Orgyia pseudotsugata)
|
|
Upper
crown dieback |
Spruce ips (Ips
hunteri Swaine)
|
|
| AFFECTING ROOTS: |
|
CONDITION
|
CAUSE
|
|
White
root decay with white mycelial fans between bark and wood |
Armillaria root
disease (Armillaria mellea)
|
