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UMaine Cooperative Extension: Insect Pests, Ticks & Plant Diseases


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Insect and Plant Disease Diagnostic Lab - Plant Disease Images

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Agastache (Giant Hyssop)
- Rust Signs\Symptoms Pathogen
Alder
- Alder Leaf Curl Signs\Symptoms  
- Ascochyta Leaf Spot Signs\Symptoms Pathogen
- Sooty Mold Signs\Symptoms Pathogen
Alfalfa
- Leptosphaerulina Leaf Spot Signs\Symptoms Pathogen
Alyssum
- High EC, Low pH Signs\Symptoms  
Amaryllis
- Leaf Blotch Signs\Symptoms Pathogen
Amelanchier
- Anthracnose Signs\Symptoms Pathogen
- Gymnosporangium Signs\Symptoms  
- Powdery Mildew Signs\Symptoms Pathogen
Apple
- Apple Scab Signs\Symptoms Pathogen
- Cedar-Hawthorn Rust Signs\Symptoms Pathogen
- Crown Gall Signs\Symptoms  
- Flyspeck Signs\Symptoms  
- Japanese Apple Rust Signs\Symptoms Pathogen
- Nectria Canker Signs\Symptoms Pathogen
- Sooty Blotch Signs\Symptoms  
- Winter Injury Signs\Symptoms  
Arborvitae (Thuja)
- Arborvitae Leaf Miner Signs\Symptoms Insect
- Didymascella Leaf Blight Signs\Symptoms Pathogen
- Pestalotiopsis Blight Signs\Symptoms Pathogen
- Phyllosticta (associated with leaf blight) Signs\Symptoms Pathogen
Ash
- Anthracnose Signs\Symptoms Pathogen
- Ash Rust Signs\Symptoms Pathogen
- Flower Gall Signs\Symptoms
Astilbe
- Discosia Signs\Symptoms Pathogen
- Powdery Mildew Signs\Symptoms Pathogen
Azalea
- Leaf Gall Signs\Symptoms  
- Powdery Mildew Signs\Symptoms Pathogen
Bacopa
- Botrytis Canker Signs\Symptoms Pathogen
Basil
- Downy Mildew Signs\Symptoms Pathogen
Bay (Laurel)
- Anthracnose Signs\Symptoms Pathogen
Bean
- POTY Virus Signs\Symptoms  
- Uromyces Rust Signs\Symptoms Pathogen
- Fusarium Rot Signs\Symptoms Pathogen
Beech
- Sooty Mold Signs\Symptoms Pathogen
Birch
- Gloeosporium   Pathogen
- Marssonina Leaf Spot Signs\Symptoms Pathogen
- Powdery Mildew Signs\Symptoms Pathogen
- Septoria Signs\Symptoms Pathogen
Blueberry
- Colletotrichum Signs\Symptoms Pathogen
- Leaf Rust Signs\Symptoms Pathogen
- Phomopsis Canker and Tip Blight Signs\Symptoms Pathogen
- Witches’ Broom Signs\Symptoms  
Bouncing Bet
- Alternaria Leaf Spot Signs\Symptoms Pathogen
Boxwood
- Boxwood Leaf Miner Signs\Symptoms Insect
- Volutella Blight Signs\Symptoms Pathogen
Brambles
- Orange Rust Signs\Symptoms Pathogen
Buckthorn
- Crown Rust Signs\Symptoms Pathogen
Bugbane
- Ascochyta Leaf Spot Signs\Symptoms Pathogen
Cabbage
- Black Rot Signs\Symptoms Pathogen
Calendula
- Fusarium Wilt Signs\Symptoms Pathogen
Calibrachoa
- Black Root Rot Signs\Symptoms Pathogen
- Calibrachoa Mottle Virus Signs\Symptoms  
- Tobacco Mosaic Virus Signs\Symptoms  
Carrot
- Alternaria Leaf Blight Signs\Symptoms Pathogen
Celery
- Alternaria Blight Signs\Symptoms Pathogen
Chard
- Cercospora Leaf Spot Signs\Symptoms Pathogen
Cimicifuga
- Ascochyta Leaf Spot Signs\Symptoms Pathogen
Cissus
- Powdery Mildew Signs\Symptoms  
Clematis
- Leaf Spot Signs\Symptoms Pathogen
Coleus
- Downy Mildew Signs\Symptoms Pathogen
Corn
- Common Smut Signs\Symptoms Pathogen
- Alternaria Leaf Blight Signs\Symptoms Pathogen
Corylus
- Eastern Filbert Blight Signs\Symptoms Pathogen
Cosmos
- White Smut Signs\Symptoms Pathogen
Crucifers
- Club Root Signs\Symptoms  
Cucurbits
- Alternaria Leaf Spot Signs\Symptoms Pathogen
- Anthracnose Signs\Symptoms Pathogen
- Bacterial Wilt Signs\Symptoms  
- Belly Rot Signs\Symptoms Pathogen
- Black Rot Signs\Symptoms Pathogen
- Fusarium rot Signs\Symptoms  
- Gummy Stem Blight Signs\Symptoms Pathogen
- Phytophthora Fruit Rot Signs\Symptoms Pathogen
- Powdery Mildew Signs\Symptoms Pathogen
- Scab Signs\Symptoms Pathogen
- Septoria Leaf Spot Signs\Symptoms Pathogen
- Rodent Damage Response Signs\Symptoms  
- Unidentified Phytotoxicity Signs\Symptoms  
Daphne
- Tubercularia Signs\Symptoms Pathogen
Daylily
- Aureobasidium Signs\Symptoms Pathogen
- Leaf Streak Signs\Symptoms Pathogen
Delphinium
- Phoma Signs\Symptoms Pathogen
Dogwood
- Dogwood Anthracnose Signs\Symptoms Pathogen
- Golden Canker Signs\Symptoms Pathogen
- Powdery Mildew 1 Signs\Symptoms Pathogen
- Powdery Mildew 2 Signs\Symptoms Pathogen
- Septoria Leaf Spot Signs\Symptoms Pathogen
Douglas Fir
- Rhabdocline Needle Cast Signs\Symptoms  
- Swiss Needle Cast Signs\Symptoms Pathogen
Elder
- Leaf Spot Signs\Symptoms Pathogen
Elm
- Dutch Elm Disease Signs\Symptoms Pathogen
- Phomopsis (secondary?) Signs\Symptoms Pathogen
Euonymus
- Crown Gall Signs\Symptoms  
- Tubercularia Signs\Symptoms Pathogen
Fig
- Rust Signs\Symptoms Pathogen
Fir
- Broom Rust Signs\Symptoms Pathogen
- Cylindrocarpon Signs\Symptoms Pathogen
- Fir-Fern Rust Signs\Symptoms Pathogen
- Phyllosticta Needle Blight 1 Signs\Symptoms Pathogen
- Phyllosticta Needle Blight 2 Signs\Symptoms Pathogen
- Rhizosphaera Needle Cast Signs\Symptoms Pathogen
Fothergilla
- Botrytis Signs\Symptoms Pathogen
Fuchsia
- Insecticidal Soap Damage Signs\Symptoms  
Garlic
- Embellisia Bulb Canker Signs\Symptoms Pathogen
- Garlic Bloat Signs\Symptoms Pathogen
- Mushy Rot Signs\Symptoms Pathogen
- POTY Virus Positive Signs\Symptoms  
- Rust Signs\Symptoms Pathogen
- White Rot 1 Signs\Symptoms  
- White Rot 2 Signs\Symptoms  
Geranium
- Bacterial Wilt Signs\Symptoms  
- Botrytis Leaf Spot Signs\Symptoms Pathogen
- Oedema Signs\Symptoms  
- Pelargonium Flower Break Virus Signs\Symptoms  
- Pythium Root Rot Signs\Symptoms  
- Yellow Net Vein Virus Signs\Symptoms  
Gladiolus
- White Rot Signs\Symptoms  
Grape
- Black Rot Signs\Symptoms Pathogen
- Downy Mildew Signs\Symptoms Pathogen
Hawthorn
- Entomosporium Signs\Symptoms Pathogen
- Phomopsis Canker Signs\Symptoms  
Hazelnut
- Eastern Filbert Blight Signs\Symptoms Pathogen
Hemlock
- Hemlock Rust Signs\Symptoms Pathogen
- Hemlock Tip Blight Signs\Symptoms Pathogen
Heuchera
- Rust Signs\Symptoms Pathogen
Hickory
- Ascochyta Signs\Symptoms Pathogen
- Powdery Mildew Signs\Symptoms Pathogen
Holly
- Glyphosate Injury Signs\Symptoms  
Hollyhocks
- Rust Signs\Symptoms Pathogen
Honeysuckle
- Leaf Blight Signs\Symptoms Pathogen
- Powdery Mildew Signs\Symptoms Pathogen
Hops
- Downy Mildew Signs\Symptoms Pathogen
Horsechestnut
- Guignardia Blotch Signs\Symptoms Pathogen
Hosta
- Alternaria Leaf Spot Signs\Symptoms Pathogen
- Botrytis Leaf Spot Signs\Symptoms Pathogen
- Cercospora Signs\Symptoms Pathogen 
- Crown Rot Signs\Symptoms Pathogen 
- Hosta Virus X Signs\Symptoms  
Hydrangea
- Ascochyta Signs\Symptoms Pathogen
- Gray Mold Signs\Symptoms Pathogen
Impatiens, Garden
- Alternaria Leaf Spot Signs\Symptoms Pathogen
- Downy Mildew Signs\Symptoms Pathogen
Impatiens, New Guinea
- Myrothecium Leaf Spot Signs\Symptoms Pathogen
Ipomoea
- Oedema Signs\Symptoms  
Iris
- Leaf Spot Signs\Symptoms Pathogen
- Rhizome Rot Signs\Symptoms Pathogen
Jack-in-the-pulpit
- Rust Signs\Symptoms Pathogen
Jostaberry
- White Pine Blister Rust Signs\Symptoms Pathogen
Juniper
- Gymnosporangium Rust Signs\Symptoms Pathogen
- Kabatina Blight 1 Signs\Symptoms Pathogen
- Kabatina Blight 2 Signs\Symptoms Pathogen
- Leptosphaeria (secondary?) Signs\Symptoms Pathogen
- Mytilinidion (secondary) Signs\Symptoms Pathogen
- Oidiodendron (secondary) Signs\Symptoms Pathogen
- Ojibwaya perpulchra (secondary) Signs\Symptoms Pathogen
- Phomopsis Twig Blight Signs\Symptoms Pathogen
- Tip Blight Signs\Symptoms Pathogen
Kale
- Leptosphaerulina Leaf Blight Signs\Symptoms Pathogen
Lamium
- Downy Mildew Signs\Symptoms Pathogen
Lemon
- Anthracnose Signs\Symptoms Pathogen
Lettuce
- Downy Mildew Signs\Symptoms Pathogen
- Leaf Spot Signs\Symptoms Pathogen
Lilac
- Anthracnose Signs\Symptoms Pathogen
- Ascochyta Blight Signs\Symptoms Pathogen
- Leaf Spot Signs\Symptoms Pathogen
Lily
- Botrytis Blight Signs\Symptoms  
- Poor bulb storage Signs\Symptoms  
Mallow
- Rust Signs\Symptoms Pathogen
Maple
- Anthracnose 1 Signs\Symptoms Pathogen
- Anthracnose 2 Signs\Symptoms Pathogen
- Cristulariella Leaf Spot Signs\Symptoms Pathogen
- Leaf Blister Signs\Symptoms Pathogen
- Stegonsporium Canker Signs\Symptoms Pathogen
- Tar Spot Signs\Symptoms Pathogen
Mayapple
- Rust Signs\Symptoms Pathogen
Mountain Ash
- Entomosporium Leaf Spot Signs\Symptoms Pathogen
Mountain Laurel
- Phytophthora Leaf Spot Signs\Symptoms  
Myrtle
- Black Root Rot Signs\Symptoms Pathogen
- Rust Signs\Symptoms Pathogen
Ninebark
- Powdery Mildew 1 Signs\Symptoms Pathogen
- Powdery Mildew 2 Signs\Symptoms Pathogen
Oak
- Anthracnose Signs\Symptoms Pathogen
- Leaf Blister Signs\Symptoms Pathogen
- Tubakia Leaf Spot Signs\Symptoms Pathogen
- Botryosphaeria Canker Signs\Symptoms Pathogen
- Oak Leaf Gall Signs\Symptoms  
- Taphrina Signs\Symptoms Pathogen
Oat
- Crown Rust Signs\Symptoms Pathogen
Onion
- Purple Blotch Signs\Symptoms Pathogen
- Storage Rot Signs\Symptoms Pathogen
Orchid
- Dendrobium – Anthracnose Signs\Symptoms Pathogen
- Miltonia – Anthracnose Signs\Symptoms
- Oncidium – Anthracnose Signs\Symptoms
Pachysandra
- Volutella Blight Signs\Symptoms  
Pansy
- Black Root Rot Signs\Symptoms Pathogen
Parsley
- Septoria Leaf Spot Signs\Symptoms Pathogen
Pea
- Ascochyta Leaf and Pod Spot Signs\Symptoms Pathogen
- Black Root Rot Signs\Symptoms Pathogen
- Mycosphaerella Blight Signs\Symptoms Pathogen
- Powdery Mildew Signs\Symptoms Pathogen
Pear
- Fabraea Leaf Spot Signs\Symptoms Pathogen
- Pear Scab Signs\Symptoms Pathogen
Peony
- Anthracnose Signs\Symptoms Pathogen
- Botrytis Signs\Symptoms Pathogen
- Cercospora Leaf Spot Signs\Symptoms Pathogen
- Leaf Blotch Signs\Symptoms Pathogen
- Peony Ringspot Virus Signs\Symptoms  
Pepper
- Anthracnose Signs\Symptoms Pathogen
- Fruit Rot Signs\Symptoms Pathogen
- Fusarium Signs\Symptoms Pathogen
- Thrips Damage Signs\Symptoms Insect
- Oedema Signs\Symptoms  
Petunia
- Low pH; High Soluble Salt Signs\Symptoms  
Phlox
- Downy Mildew Signs\Symptoms Pathogen
- Powdery Mildew Signs\Symptoms Pathogen
- Septoria Leaf Spot Signs\Symptoms Pathogen
Pieris
- Pestalotiopsis Leaf Spot Signs\Symptoms Pathogen
Pine
- Bifusella Needle Blight Signs\Symptoms Pathogen
- Coleosporium Needle Rust Signs\Symptoms Pathogen
- Cyclaneusma Signs\Symptoms Pathogen
- Davisomycella Needle Blight Signs\Symptoms Pathogen
- Dothistroma Signs\Symptoms Pathogen
- Lophodermium Needle Blight Signs\Symptoms Pathogen
- Ploioderma Needle Cast Signs\Symptoms Pathogen
- Salt damage Signs\Symptoms  
- Sarea resinae (Secondary?) Signs\Symptoms Pathogen
- Sphaeropsis (Diplodia) Blight Signs\Symptoms Pathogen
- Stagonospora (Secondary?) Signs\Symptoms Pathogen
- Truncatella Needle Blight Signs\Symptoms Pathogen
- White Pine Blister Rust Signs\Symptoms Pathogen
Poppy
- Alternaria Leaf Spot Signs\Symptoms Pathogen
- Anthracnose Rot 1 Signs\Symptoms Pathogen
- Anthracnose Rot 2 Signs\Symptoms Pathogen
Potato
- Alternaria Leaf Spot Signs\Symptoms Pathogen
- Botrytis Signs\Symptoms Pathogen
- Chimeric Variegation Signs\Symptoms  
- Common Scab Signs\Symptoms  
- Fusarium Tuber Rot Signs\Symptoms Pathogen
- Growth Cracks Signs\Symptoms  
- Herbicide Damage Signs\Symptoms  
- Late Blight Signs\Symptoms Pathogen
- Potato Virus Y Signs\Symptoms  
- Unidentified Signs\Symptoms Pathogen
Privet
- Thedgonia Leafspot Signs\Symptoms Pathogen
Quince
- Rust Signs\Symptoms Pathogen
Raspberry
- Anthracnose Signs\Symptoms Pathogen
- Raspberry Cane Maggot Signs\Symptoms Insect
- Orange Rust Signs\Symptoms Pathogen
Rhododendron
- Gray Leaf Blight Signs\Symptoms Pathogen
Rose
- Black Spot Signs\Symptoms Pathogen
- Rose Midge Signs\Symptoms  
- Rust Signs\Symptoms Pathogen
Rosemary
- Botrytis Signs\Symptoms Pathogen
- Powdery Mildew Signs\Symptoms  
Rudbeckia
- Downy Mildew Signs\Symptoms Pathogen
- Septoria Signs\Symptoms  
Rye
- Ergot Signs\Symptoms  
Schlumbergera
- Oedema Signs\Symptoms  
Shepherd’s Purse
- Downy Mildew Signs\Symptoms Pathogen
Soybean
- Downy Mildew Signs\Symptoms Pathogen
Spinach
- Cladosporium Leaf Spot 1 Signs\Symptoms Pathogen
- Cladosporium Leaf Spot 2 Signs\Symptoms Pathogen
- Downy Mildew Signs\Symptoms Pathogen
Spruce
- Frost Injury Signs\Symptoms  
- Herbicide Injury Signs\Symptoms  
- Rhizosphaera Needle Cast Signs\Symptoms Pathogen
- Sirococcus Blight Signs\Symptoms Pathogen
- Spruce Needle Rust Signs\Symptoms Pathogen
- Stigmina infection Signs\Symptoms Pathogen
- Weir’s Cushion Rust Signs\Symptoms Pathogen
Stone Fruit (Prunus)
- Black Knot Signs\Symptoms  
- Blumeriella Leaf Spot Signs\Symptoms Pathogen
- Brown Rot Signs\Symptoms Pathogen
- Cherry Leaf Spot Signs\Symptoms Pathogen
- Peach Leaf Curl Signs\Symptoms Pathogen
- Peach Scab Signs\Symptoms Pathogen 
- Peach Botrytis Signs\Symptoms Pathogen
- Powdery Mildew Signs\Symptoms Pathogen
Strawberry
- Botrytis Rot Signs\Symptoms Pathogen
- Strawberry Leaf Spot Signs\Symptoms Pathogen
Sunflower
- Septoria Leaf Spot Signs\Symptoms Pathogen
Sweet Potato
- Oedema Signs\Symptoms
Sweetbay Magnolia
- Anthracnose Signs\Symptoms Pathogen
Tomato
- Alice the Goon    
- Alternaria Stem Canker Signs\Symptoms Pathogen
- Anthracnose Signs\Symptoms  
- Blossom End Rot Signs\Symptoms  
- Chimeric Variegation Signs\Symptoms  
- Cristulariella Leaf Spot Signs\Symptoms Pathogen
- Early Blight Signs\Symptoms Pathogen
- Late Blight Signs\Symptoms Pathogen
- Leaf Mold Signs\Symptoms Pathogen
- Magnesium Deficiency Signs\Symptoms  
- Oedema Signs\Symptoms  
- Septoria Leaf Spot Signs\Symptoms Pathogen
- Stemphylium Leaf Spot Signs\Symptoms Pathogen
- Thrips Damage Signs\Symptoms Insect
- White Mold Signs\Symptoms  
Tulip
- Botrytis Bulb Rot Signs\Symptoms Pathogen
Turf
- Anthracnose Signs\Symptoms Pathogen
- Crown Rust Signs\Symptoms Pathogen
- Leptosphaerulina Signs\Symptoms Pathogen
- Red Thread Signs\Symptoms Pathogen
- Slime Mold Signs\Symptoms  
- Smut Signs\Symptoms Pathogen
Veronica
- Phoma Rot Signs\Symptoms Pathogen
Vinca
- Phoma Stem Rot Signs\Symptoms Pathogen
Violet
- Rust Signs\Symptoms Pathogen
Wheat
- Leaf Rust Signs\Symptoms Pathogen
- Loose Smut Signs\Symptoms Pathogen
- Powdery Mildew Signs\Symptoms Pathogen
- Tan Spot Signs\Symptoms Pathogen
Witchhazel
- Blight Signs\Symptoms Pathogen
- Gonatobotryum Signs\Symptoms Pathogen
- Seimatosporium Signs\Symptoms Pathogen
Wild Ginger
- Black Root Rot Signs\Symptoms Pathogen
Zinnia
- Alternaria Leaf Spot Signs\Symptoms Pathogen

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University of Maine Cooperative Extension


Contact Information

UMaine Cooperative Extension: Insect Pests, Ticks & Plant Diseases
491 College Avenue
Orono, Maine 04473-1295
Phone: 207.581.3880, 800.287.0279 (in Maine) or 800.287.8957 (TDD)E-mail: extension@maine.edu
The University of Maine
Orono, Maine 04469
207.581.1110
A Member of the University of Maine System