Maple, American
Symptom Cause  
Irregular tan or brown spots on leaves at veins; expand until leaves die; sometimes sunken spots on leaves
Anthracnose (on plants)
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Leaves wrinkled; stunted; leaves fall off
Aphids
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Limbs die; large holes appear; starting at top of tree
Asian Longhorn Beetle
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Swollen; bleeding lesions appear on stems and trunk
Bacterial Canker
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Small holes in bark and stems surrounded by sawdust
Borers
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Tree grows poorly
Crowded Roots
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Young portions of foliage disappear, or young tips disappear, bark peeled off
Deer
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Leaves small, mottled yellow and brown, distorted; defoliates tree
Pear Thrips
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Bark of trunk and roots gnawed
Rodent Injury
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Small bumps on leaves and branches
Scale Insects
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Mushrooms sprout at base of tree
Shoestring Root Rot (fungus)
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Black powdery sooty mold fungus forms on honeydew; branches may die
Sooty Mold
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Tree is stunted
Too Close to Black Walnut Tree
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