| AFFECTING LEAVES: |
|
CONDITION
|
CAUSE
|
 |
Leaves
chewed:Normal chewing injuries, primarily confined to leaf edges |
Brownheaded Ash
Sawfly (Tomostethus multicinctus);
Forest
tent caterpillar (Malacosoma disstria; Hubner);
Fruittree
leafroller (Archips argyrospilus)
|
|
Smooth
semicircular cuts made on leaf edge |
Leafcutter Bees (Megachile
spp.)
|
|
Blackened
spotting of leaves |
Ash Anthracnose (Apiognomonia
sp.)
|
|
Leaflets being distorted and/or killed back |
Ash plant bug (Tropidosteptes
amoenus Reuter)
|
|
Flecking
wounds on leaves |
Ash plant bug (Tropidosteptes
amoenus Reuter) or Lacebug (Corythuca spp.)
|
|
Leaves
bronzed: “Brittle-leaf” condition |
Eriophyid mites
|
|
Leaflets
thickened and curled at midrib |
Ash midrib gall midge
(contarinia canadensis Felt)
|
|
Leaves
tightly curled and thickened |
Leafcurl ash aphid (Prociphilus
fraxinifolii)
|
|
General
distortion of leaf, with thickened veins |
Herbicide
injury
|
|
White
powdery material on upper or lower surface of leaf |
Powdery mildew
|
|
Wilting
of portions of tree: originating from roots |
Verticillium wilt (Verticillium
spp.)
|
|
| AFFECTING TWIGS OR SMALLER BRANCHES: |
|
CONDITION
|
CAUSE
|
|
Twig
dieback with small exit holes or ventilation holes visible |
Ash bark beetles (Hylesinus
spp.)
|
|
Twig
dieback with small pimple-like fruiting bodies (pycnidia) in the bark |
Cytospora canker (Valsa
spp., Leucostoma spp.)
|
|
Witches’
brooming symptoms |
Ash yellows (Phytoplasma)
|
|
Scales |
Oystershell scale (Lepidosaphes
ulmi) or European fruit
lecanium (Parthenolecanium corni)
|
|
| AFFECTING LARGER BRANCHES OR TRUNK: |
|
CONDITION
|
CAUSE
|
|
Tunneling
in trunk |
Lilac/Ash borer,
Banded ash clear wing, (Podosesia syringa);
Ash bark beetles (Hylesinus spp.);
Redheaded
ash borer (Neoclytus acuminatus)
|
|
Masses
of caterpillars resting on bark |
Forest
tent caterpillar (Malacosoma disstria Hubner)
|
|
Discolored
areas and dead bark containing small pimple-like fruiting bodies
(pycnidia) |
Cytospora canker (Valsa
spp., Leucostoma spp.)
|
|
Clear to
white oozing or frothy malodorous liquid exiting from wounds |
Bacterial wetwood/slime
flux
|
|
Large,
dead areas of bark on southwest side of trunk |
Winter sunscald
|
|
Open
wounds, internal decay, swollen areas on stem |
Stem decay fungi (Perenniporia
fraxinophila, Phellinus punctatus, and various fungal genera)
|
|
Fungal
fruiting bodies (mushrooms, conks) present |
Stem decay fungi (Perenniporia
fraxinophila, Phellinus punctatus, and various fungal genera)
|
|
Wilting
and dieback of portions of tree, originating from roots |
Verticillium wilt (Verticillium
spp.)
|
|
| AFFECTING FLOWERS: |
|
CONDITION
|
CAUSE
|
|
Distorted
flowers |
Ash flower gall mite (Eriophyes
fraxiniflora)
|
