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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Oak > Pale, white or opaque discoloration of leaves

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Oak > Leaves > Pale, white or opaque discoloration of leaves

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  • Image: Oak lace bug 1
  • Image: Oak lace bug 2
  • Image: Oak lace bug 3

Oak lace bug
Corythucha arcuata

  • White or yellow speckled or pinprick discolorations on upper side of leaf
  • Defoliation can occur when trees are severely infested
  • Lace bugs are 1/4 inch long; light colored bodies; intricate, lacy wings
  • More information on Oak lace bug...
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  • Image: Oak leaf blister 1
  • Image: Oak leaf blister 2
  • Image: Oak leaf blister 3

Oak leaf blister
Taphrina caerulescens

  • Leaf blisters are initially pale green to orange, but turn brown with age
  • Raised blister-like leaf spots; appear sunken from the underside of the leaf
  • Blister areas range from 1/16 to 1/2 inch in length
  • Heavy infestation will cause leaf to curl after the blisters have merged together
  • Leaves do not drop
  • Damage most common in spring as leaves are growing during wet weather
  • More information on Oak leaf blister...
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  • Image: Iron chlorosis 1
  • Image: Iron chlorosis 2
  • Image: Iron chlorosis 3

Iron chlorosis

  • Leaf blades that are supposed to be green are yellow but leaf veins remain green
  • Affected trees have poor growth, undersized leaves
  • Most severe on branch tips or new growth
  • Common on pin oaks (Quercus palustris)
  • More information on Iron chlorosis...
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  • Image: Oak leaf miner 1
  • Image: Oak leaf miner 2
  • Image: Oak leaf miner 3

Oak leaf miner
Cameraria spp.

  • Larvae feed between leaf surfaces creating blotch-like mines
  • Canopy looks brown when heavily infested; defoliation can occur
  • Larvae 1/4 inch long with bodies that taper to rear, although larvae are rarely seen
  • Primarily attacks white oak
  • More information on Oak leaf miner...
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  • Image: Powdery mildew 1
  • Image: Powdery mildew 2
  • Image: Powdery mildew 3

Powdery mildew
Phyllactinia guttata

  • White or gray powdery mats resembling talcum powder occur in spots, blotches or coat leaves
  • Lower shaded leaves are most commonly affected, common on small understory trees
  • Severely infected leaves are often curled or distorted
  • Damage is common in spring or fall
  • More information on Powdery mildew...
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  • Image: Oak slug sawfly 1
  • Image: Oak slug sawfly 2
  • Image: Oak slug sawfly 3

Oak slug sawfly
Caliroa quercuscoccineae

  • Larvae windowpane feed underside of leaf, i.e. chew leaf one layer of leaf tissue between the veins creating a lacelike appearance
  • Larvae is dark green to black and covered in slime; adult is non-stinging wasp that is rarely seen
  • Damage first visible early summer
  • Pin oak and black oak are preferred hosts
  • More information on Oak slug sawfly...

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