Michigan State University Extension
Ornamental Plants plus Version 3.0 - 00000296
11/12/99
CARYA INSECT PROBLEMS
Aphids of various types feed on hickory causing distorted
and stunted growth. The hickory leaf stem gall aphid
causes the formation of hollow green galls on leaves,
stems, and twigs. The galls form in June and turn black
in July. The galls are up to a half inch in diameter.
Hickory bark beetles mine the bark and sapwood. The
boring cause wilting of young twigs or trunks may be
girdled and trees killed. Keep trees healthy by
fertilizing regularly and by watering during dry weather.
No chemical control is registered for this pest.
The twig girdler larva girdles twigs causing weakened
twigs to break off and drop. The larva is about a half
inch long and rides the branch to the ground where it
overwinters. Gather the fallen twigs and destroy them.
No chemical control is registered for this insect.
June beetles eat the leaves of hickory at night. The
injury is usually not severe but can be mysterious since
no insects are seen during the day.
Caterpillars of various types feed on hickory. Some
caterpillars can be controlled with sprays of Bacillus
thuringiensis, a bacterial disease affecting some types
of caterpillars.
Scales of various types attack hickory but can be
controlled with dormant and crawler sprays of properly
labeled chemicals.
Related information.
Pesticide Recommendations
Aphids on Ornamentals
Fall Webworm
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This file was generated from data base ZZ on 01/19/00.
Data base ZZ was last revised on 11/12/99.
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