Symptoms of Emerald Ash Borer Infestation
Tagged as: EAB, Emerald Ash Borer, emerald ash borer in Illinois
Emerald ash borer (EAB) infestations often go undetected until the trees begin to show symptoms. A tree may be infested for a year or more before symptoms first appear. The symptoms listed below may indicate the presence of emerald ash borer:
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Figure 1 D-shaped exit holes (approximately 1/8 inch in diameter) on the branches and trunk. These are often found first in the upper portions of the tree. Due to the rough texture of ash bark, the holes may be difficult to locate.
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Figure 4 Larvae tunnel distinct serpentine (S-shaped) galleries packed with excrement under bark. Vertically split or cracked bark may occur above theses larval feeding galleries. Photo credit: Art Wagner; USDA/APHIS/PPQ |
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Figure 5 Jagged holes produced by woodpeckers working to extract larvae from the tree. The tan color of these woodpecker sites stand out against the gray color of the bark. Photo credit: Minnesota Department of Agriculture |
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Figure 6 A large number of shoots or suckers can grow below the dead portions of the tree, particularly at the tree base. This usually happens when the tree has been infested for some time and a large portion of the canopy has died.
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Updated 2012
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