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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous > Honeylocust > Unusually colored bark on branch or trunk

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Honeylocust > Branches > Unusually colored bark on branch or trunk

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  • Image: Honeylocust borer 1
  • Image: Honeylocust borer 2

Honeylocust borer
Agrilus difficilis

  • Wet spots due to sap-stains on bark around infestation sites
  • Removal of bark reveals frass filled galleries
  • “D” shaped exit holes found in declining branches
  • Adults are 5/16- ½ inch long, bullet-shaped with characteristic whitish to yellowish bands on abdomen
  • Adults make notches along leaf margins while feeding
  • More information on Honeylocust borer
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  • Image: Lichens 1
  • Image: Lichens 2
  • Image: Lichens 3

Several species

  • Colorful patches on the bark of trunk and/or branches
  • Can be wrinkled, in scalloped sheets, lace-like pads, bushy tufts, paint-like spots or splashes
  • Forms can be flat against the bark surface or raised in leaf-like lobes, finger-like or hairy projections
  • Colors may be shades of gray, green, blue, yellow, orange, or red
  • Lichens do not harm trees or shrubs and no management is necessary
  • More information on Lichens
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  • Image: Coral spot canker 1
  • Image: Coral spot canker 2
  • Image: Coral spot canker 3

Coral spot canker
Nectria cinnabarina

  • Sunken dark brown area on branch that is often cracked or has a ridge at the edge
  • Raised cushion-like bumps on affected branches, may be cream to orange or red, turn black with age
  • Dead branches and twigs, often first observed in early spring when no leaves form
  • Or, wilting soon after leaves emerge in spring
  • Common on trees stressed by drought, recent transplant or other factors
  • More information on Coral spot canker

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