| AFFECTING LEAVES: |
|
CONDITION
|
CAUSE
|
 |
Blackened
and wilting leaves |
Fireblight (Erwinia
amylovora)
|
|
Pale
green or yellow leaves |
Iron chlorosis
|
|
Caterpillars
associated with webbing |
Fall webworm (Hyphantria
canea) or Western
tent caterpillar (Malacosoma californicum)
|
|
Chewing
leaves |
Pearslug (Caliroa
cerasi) or Forest
tent caterpillar (Malacosoma disstria)
|
|
Leaves
curled in spring |
Apple aphid (Aphis pomi)
|
|
Reddish
spotting on upper surface/orange pustules, spiny eruption on underside |
Cedar-Apple Rust (Gymnosporangium rusts)
|
|
| AFFECTING TWIGS AND SMALLER BRANCHES: |
|
CONDITION
|
CAUSE
|
|
Blackened,
wilting, and crooked tips |
Fireblight (Erwinia
amylovora)
|
|
White,
wax-covered insects |
Mealybug (Pseudococcidae)
or Wooly hawthorn aphid (Eriosoma
crateagi)
|
|
| AFFECTING LARGER BRANCHES OR TRUNK: |
|
CONDITION
|
CAUSE
|
|
Clear to
white oozing or frothy malodorous liquid exiting from wounds |
Bacterial wetwood and
slime flux
|
