TreeIssues

Pest & Disease Forecast for Maine

It's September — 167 tracked threats are active right now in Maine. Each timeline shows estimated activity across the year.

Active nowWatch closely — these threats are at or near peak activity this month.
Emerald Ash Borer
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Japanese Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Dutch Elm Disease
DiseaseCRITICAL

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Fire Blight
DiseaseHIGH

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Cedar-Apple Rust
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Powdery Mildew
FungusLOW

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Apple Scab
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Chestnut Blight
FungusCRITICAL

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Beech Leaf Disease
DiseaseHIGH

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Armillaria Root Rot
FungusHIGH

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Rhizosphaera Needlecast
FungusHIGH

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Bronze Birch Borer
InsectHIGH

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Tar Spot
FungusLOW

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Asian Longhorned Beetle Damages hardwood trees by tunneling deep into trunks and branches
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Asian Lady Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Common Ringlet
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Two-spotted Grass Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Polyphemus Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
North American Luna Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
One-eyed Sphinx
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
dead man's fingers
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Pale Brittlestem
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
American Yellow Fly Agaric
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
American Lady
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Waved Sphinx
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Brown Marmorated Stink Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
crown-tipped coral fungus
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Red-rot Decay Stag Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Poor Man's Licorice
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Lynx Paw Oyster
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Orange Jelly Spot
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Homaeotarsus bicolor
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Alfalfa Plant Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Green Stink Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Modest Sphinx
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Nymphula Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Dark-spotted Palthis Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Cloudy Arches Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Dark-banded Owlet
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Four-lined Plant Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Frost's Amanita
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
common puffball
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Knotted Wrack
OtherMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
bladder wrack
OtherMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Io Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Rosy Maple Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Banded Tussock Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Small Milkweed Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Japanese Maple Leafhopper
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Northern Red Belt
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
turkey-tail
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
hemlock varnish shelf
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Spotted Tussock Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
North American Common Gray
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Twice-stabbed Stink Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
White-pored Chicken of the Woods
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Hooded Tube Lichen
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Hooded Rosette Lichen
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
brown cobblestone lichen
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Agreeable Tiger Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
North American Tarnished Plant Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Reddish-brown Stag Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Yellow-fringed Dolichomia Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Large Lace-border Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Double-banded Grass-veneer
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
chicken of the woods
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Common Sunburst Lichen
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Oriental Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Yellow Patches
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Oak Timberworm
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Three-spined Grass Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Newfoundland chanterelle
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Purple-crested Slug Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Hesperomyces harmoniae
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Black-staining Polypore
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Berkeley's Polypore
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Nipponoserica peregrina
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Painted Lichen Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Lesser Maple Spanworm Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Sordid Underwing
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Boxwood Leaftier Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
concentric boulder lichen
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Bronze Ground Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Asiatic Garden Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Northern Tooth
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Spiral Wrack
OtherMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
lobster mushroom
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Velvet-footed Tap
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Tree Lungwort
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Brown Prionid
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
American Giant Water Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Western Conifer Seed Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Pale Green Assassin Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Phaeolus hispidoides
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
quince rust
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Spotted Pink Lady Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Tomentose Burying Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Metatropiphorus belfragii
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Reticulated Net-winged Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Phytocoris tibialis
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Blackening Russula
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Carolina Sphinx
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Chicken Fat Mushroom
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Fourteen-spotted Lady Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Mycetina perpulchra
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Elegant Grass-veneer
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
chaga
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
American Carrion Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Black Vine Weevil
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Roundneck Sexton Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Pink Underwing
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Ornate-stalked bolete
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Frost's Bolete
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Sieve kelp
OtherMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Hairy-necked Tiger Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Praeclara Underwing Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Ultronia Underwing
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Ambiguous Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
British soldier lichen
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Salt Marsh Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Lilac-brown bolete
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Clymene Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Giant Cladonia Lichen
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Black-rimmed Prominent
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Armyworm Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Blushing Rosette
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Common Toadskin Lichen
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Milkweed Tussock Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Master's Dart
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Relict Rhinoceros Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Purple Arches Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Green Cone-headed Planthopper
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Pink Earth Lichen
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Strawberry Root Weevil
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Northern Dog-day Cicada
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Swamp Cicada
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Sumac Gall Aphid
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
White-marked Tussock Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Large Milkweed Bug
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Large Maple Spanworm Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
birch polypore
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Pale Beauty
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Definite Tussock Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Ilia Underwing
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Northern Cinnabar Polypore
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Asian Oak Weevil
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Meal moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Smith's Dart
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Zigzag Herpetogramma Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Dryad's Saddle
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Red-banded Leafhopper
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Sharp-scaly Pholiota
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Monarch
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
shaggy scalycap
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
devil's dipstick
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Locust Borer
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Gem Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Hemlock Looper Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Gold-striped Leaftier Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
American Idia Moth
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Swamp Milkweed Leaf Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
End Band Net-winged Beetle
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Small White
InsectMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
Oyster Mushroom
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
common bird's nest fungus
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
Oarweed
OtherMODERATE

Peak activity: Summer

J
F
M
A
M
J
J
A
S
O
N
D
ash-tree bolete
FungusMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
On the horizonRamping up over the next 1–2 months. Now is the time to prepare.
Hemlock Woolly Adelgid
InsectMODERATE

Peak activity: Winter

J
F
M
A
M
J
J
A
S
O
N
D
Quiet for nowLow activity this month, but still present in the region.
Spongy Moth (formerly Gypsy Moth)
InsectMODERATE

Peak activity: Spring

J
F
M
A
M
J
J
A
S
O
N
D
← National forecast|All Maine threats →|Get monthly care reminders →

Activity windows are seasonal estimates based on pest type and known phenology for the continental US; local timing varies with weather and elevation. Always confirm with a certified arborist or your state extension office.