U of M Gardening Information: What's wrong with my plant?

Hickory > Trunk/Branches > Holes in trunk or branches

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Credit: Wisconsin Dept. of Natural Resources
Credit: J. R. Baker & S. B. Bambara, North Carolina State University, Bugwood.org
Credit: James Solomon, USDA Forest Service, Bugwood.org
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Small, 1/8th inch, round exit holes in trunk and branches
Heavily infested trees typically have sparse, yellowed leaves
Premature leaf drop and broken twigs in crown can also occur when heavily infested
Weakened, stressed trees most likely attacked, rarely infest healthy trees
High Hickory bark beetle populations are often associated with Hickory decline
Adults dark brown to black, less than ¼ inch long
More information on Hickory bark beetle...

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Leaves are wilted or undersized, thin canopy with dead branches
When bark is peeled back, numerous reddish brown oval cankers up to 1 ft. long can be seen
Bark surface often shows no symptoms, occasionally cracking or dark sunken area can be seen
Dark bleeding spots that appear in May or June indicate cankers below the bark
Groups of young green shoots (sprouts) often form along the trunk; these wilt and die within a year
Round 1/8th inch exit holes of hickory bark beetles on upper trunk
Larval galleries often visible in discolored sapwood
Trees can decline and die in as little as two years when beetle populations are high

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Evenly spaced holes in main stem, approximately ¼ inch, arranged in a linear or columnar pattern
Repetitive tapping or drumming heard
Birds with black and white patterns, often some with red, seen tapping on trees
More information on Yellow bellied sapsucker...

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Entrance holes at branch crotches can ooze sap and frass
Exit holes, ¼ - 3/8 inch wide, first appear in June
Galleries start in phloem and eventually enter into sapwood; generally not very serpentine
Larvae are ¾ to 1 inch long, cylindrical shaped bodies