| AFFECTING NEEDLES: |
|
CONDITION |
CAUSE |
 |
Mottled
yellowing of needles on a branch |
Winter exposure injury
|
|
Needles
to exterior of tree bleached or brown, developing late winter |
Winter dessication
|
|
Discoloration,
needle drop of current or previous year’s growth |
Needle casts (Bifusella
sp., Davisomycella sp., Elytoderma deormans, Lophodermella
sp., Lophoedermium sp.); or Giant conifer aphids (Cinara
spp.)
|
|
Brown
felt-like material on needles (high elevations) |
Brown felt blight (Neopeckia
coulteri)
|
|
Needles
twisted, stunted |
Eriophyid mites (Trisecatus
spp.)
|
|
Aphids
on needles |
Giant conifer aphids (Cinnara
spp.)
|
|
Scales
on needles |
Pine needle scale (Chionaspis
pinifoliae)
|
|
Whole
tree fades, reddens |
Mountain pine beetle
(Dendroctonus ponderosae Hopkins)
|
|
| AFFECTING TWIGS AND SMALLER BRANCHES: |
|
CONDITION |
CAUSE |
|
Galls on
small branches that turn bright orange/yellow in spring |
Western gall rust (Endocronartium
harknessii)
|
|
Swollen
and/or twisted terminal growth |
Herbicide injury. See Abiotic Injury.
|
|
| AFFECTING LARGER BRANCHES OR TRUNK: |
|
CONDITION |
CAUSE |
|
Tunnels
oozing popcorn-like white pitch, often near crotches |
Pine moth (Dioryctria
spp.)
|
|
Galls on
large branches or trunk |
Western gall rust (Endocronartium
harknessii)
|
|
Cankers,
with resin and squirrel chewing |
Comandra rust [in
lodgepole pine] - (Cronartium comandrae)
|
|
Roughened
bark and resin production |
White pine blister rust (on
five needle pines)
|
|
Fungal
fruiting bodies (mushrooms, conks) present |
Stem decay fungi (various
species)
|
|
Open
wounds, internal decay, swollen areas in stem |
Stem decay fungi
(various species)
|
|
Regular
row of holes |
Woodpeckers
|
|
Bark
beetles |
Engraver beetles (Ips
spp.),
Mountain
pine beetles (Dendroctonus ponderosae), or Red turpentine
beetle (Dendroctonus valens LeConte)
|
|
Small
shoots emerging from the branch |
Dwarf mistletoe (Arceuthobium
sp.)
|
|
| 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 CONES: |
|
CONDITION |
CAUSE |
| |
Cones
tunneled by caterpillars |
Coneworms (Dioryctria spp.)
|
|
Sucking on developing cones. |
Conifer Seed Bugs
|
