Pest identification
What's eating my shellbark hickory?
Hickory nut curculio (Curculio caryatrypes)
Signs: Weevils snout-bore into the large developing nut to oviposit; larvae consume the kernel fully; infested nuts drop in July with a visible entry hole and frass plug.
Control: Apply carbaryl at nut sizing (late June) and again two weeks later; collect and destroy all dropped nuts to reduce soil-overwintering pupae.
Hickory shuckworm (Cydia caryana)
Signs: Larvae tunnel through the thick husk; heavy infestation prevents normal husk split, leaving nuts trapped in blackened, adhesive shucks.
Control: Pheromone-trap monitoring from June; spinosad or carbaryl at peak adult flight; remove and destroy infested shucks at harvest.
Squirrels
Signs: The large, energy-rich nut is a premium squirrel food; crop losses of 60–90% are common in mixed woodland settings; even caged young trees are raided.
Control: Metal trunk banding starting at least 6 ft high; caging of individual small trees; aggressive live trapping through September–October.
Keep shellbark hickory pest-free
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Shellbark Hickory pests — FAQ
What is eating my shellbark hickory?
Shellbark hickory produces the largest hickory nut of any native species, making it especially attractive to squirrels and hickory nut curculio. Hickory shuckworm bores into the massive husk and occasionally reaches the kernel. Fall webworm and walnut caterpillar affect foliage in summer. The thick shell offers some protection but does not deter pre-shell-hardening weevil punctures.
How do I get rid of hickory nut curculio (curculio caryatrypes) on shellbark hickory?
Weevils snout-bore into the large developing nut to oviposit; larvae consume the kernel fully; infested nuts drop in July with a visible entry hole and frass plug. Apply carbaryl at nut sizing (late June) and again two weeks later; collect and destroy all dropped nuts to reduce soil-overwintering pupae.
How do I get rid of hickory shuckworm (cydia caryana) on shellbark hickory?
Larvae tunnel through the thick husk; heavy infestation prevents normal husk split, leaving nuts trapped in blackened, adhesive shucks. Pheromone-trap monitoring from June; spinosad or carbaryl at peak adult flight; remove and destroy infested shucks at harvest.
How do I get rid of squirrels on shellbark hickory?
The large, energy-rich nut is a premium squirrel food; crop losses of 60–90% are common in mixed woodland settings; even caged young trees are raided. Metal trunk banding starting at least 6 ft high; caging of individual small trees; aggressive live trapping through September–October.