| AFFECTING LEAVES: |
|
CONDITION
|
CAUSE
|
 |
Leaves
chewed |
Fruittree leafroller (Archips
argyrospila)
|
|
White
flecks on leaves |
Leafhopper (Erythroneura
spp.)
|
|
Black to
brown spots on leaves |
Anthracnose (Kabatiella
sp.) or
Septoria
leaf spot and canker (Septoria sp.) or Tar spot (Rhytisma
sp.)
|
|
Patches
of reddish hairs (Rocky Mountain maple) |
Eriophyid mites
|
|
Sucking
insects on leaves, often honeydew |
Boxelder and maple aphids (Periphyllus
spp.) or Cottony maple scale
(nymphs) (Pulvinaria innumerabilis)
|
|
Leaves
yellowed (particularly silver maple) |
Iron chlorosis
|
|
| AFFECTING TWIGS AND SMALLER BRANCHES: |
|
CONDITION
|
CAUSE
|
|
Twigs
with row of irregularly shredded punctures |
Cicada injury (Platypedia
putnami)
|
|
Large
cottony insect on twigs |
Cottony maple scale (Pulvinaria
innumerabilis)
|
|
| AFFECTING LARGER BRANCHES OR TRUNK: |
|
CONDITION
|
CAUSE
|
|
Clear to
white oozing or frothy malodorous liquid exiting from wounds |
Bacterial wetwood and
slime flux
|
|
Areas of
dead bark with discoloration and small pimple-like fruiting bodies
(pycnidia) in the bark |
Cytospora canker (Valsa
spp., Leucostoma spp.)
|
|
Large
dead and discolored areas on southwest side of trunk |
Winter sunscald
|
|
Borers |
Flatheaded appletree
borer (Chrysobothris femorata)
|
|
Wilting
and dieback of portions of tree, originating from roots |
Verticillium wilt (Verticillium
spp.)
|
