Willow, Corkscrew
Symptom Cause  
Leaves wrinkled; stunted; leaves fall off
Aphids
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Tissue killed, dark sunken spots in wood; leaves affected, canker on twigs.
Canker (fungus)
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Leaves eaten; trees defoliated
Caterpillars
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Young portions of foliage disappear, or young tips disappear, bark peeled off
Deer
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Tissue killed, dark sunken spots in wood; leaves affected, canker on twigs.
Dieback (fungus)
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Twigs and branches may die; sooty mold with ants
Giant Bark Aphids
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Trees defoliated, brown egg cases appear on trunk
Larvae of Gypsy Moth
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Leaves enlarged, thickened at gall; brown galls harden
Leaf Gall (fungus)
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Many holes in twigs and branches; girdled sawdust at holes; sap oozes
Mottled Willow Borers
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Rots at soil line and down in roots; spreads to trunk
Phytophthora Rot (fungus)
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Branches encrusted with small bumps
Scale Insects
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Stems and leaves covered with white, cottony, brownish, yellow, gray bumps.
Scurfy Scale
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Black powdery sooty mold fungus forms on honeydew; leaves may die
Sooty Mold
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Holes in branches; limbs girdled; sawdust evident
Willow Borers
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Leaf surface eaten; lacy appearance, tree defoliated, leaves webbed.
Willow Hornworms
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Leaf tissue eaten between veins, circular holes; foliage turn brown, dry; twigs die
Willow Leaf Beetles
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Leaves blackish, wither, drop; twigs sunken spots, die
Willow Scab (fungus)
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