Michigan State University Extension
Ornamental Plants plus Version 3.0 - 00001720
11/12/99
Bark beetles
Adults are small (2 to 4 mm), hard beetles, brown to
black, with a down-curved head barely visible from above.
The larvae burrow under the bark of weakened trees in
distinctly patterned galleries. These beetles can cause
the premature death of weakened trees. They also spread
fungal diseases, such as the Dutch elm disease. They are
gregarious insects, preferring to attack trees already
infested with bark beetles. They may also attack dead or
cut wood.
Bark beetles successfully breed in trees that are severely
stressed or dying. Newly transplanted trees may be
particularly susceptible to attack by these insects.
Proper cultural practices to promote tree vigor are often
the most important means of controlling most bark beetle
problems. Often, these techniques are sufficient for
control.
A few bark beetles are capable of killing healthy trees,
either through coordinated mass attacks or through
introduction of fungus diseases into healthy trees (elm
bark beetles). Sanitation and insecticide applications
are of great importance in managing these pest situations.
To control bark beetles with insecticide applications,
you must wet the bark thoroughly to the point of run-off
immediately prior to the egg-laying period.
This information is for educational purposes only. References
to commercial products or trade names does not imply
endorsement by MSU Extension or bias against those not
mentioned. This information becomes public property upon
publication and may be printed verbatim with credit to MSU
Extension. Reprinting cannot be used to endorse or advertise
a commercial product or company.
This file was generated from data base ZZ on 01/19/00.
Data base ZZ was last revised on 11/12/99.
For more information about this data base or its contents please contact
heatley@msue.msu.edu . Please read our
disclaimer for important
information about using our site.