Main page content begins here

What is it?

Several species of small gall wasps (Family Cynipidae) form a variety of distinctive twig and leaf galls on bur oak growing in our region.
These galls are abnormal plant growths stimulated by the developing wasp larvae. The tiny dark adult wasps are seldom seen by the homeowner.

What's the problem?

These conspicuous growths provide the wasps with food and protection, however, they often raise concerns that something is wrong with the tree. Woody galls that form on twigs may persist on the oak tree for several years after the wasps have left them.

What can I do?

Since galls on oak leaves cause mostly cosmetic damage, control is not usually required. Insecticide sprays would also be ineffective against the young wasps protected inside their galls. There are also a number of natural enemies that successfully attack gall wasps.

Woody galls on the twigs typically won't kill the branch, however, a large number of galls may reduce the amount of growth. Such galls can simply be removed by hand and destroyed.

For More Information

Pest Management

12304 107 Street NW
Edmonton AB  T5G 2S7

Telephone

In Edmonton: 311

Outside Edmonton: 780-442-5311

Fax 780-496-4978
Email treebugs@edmonton.ca

End of page content. Please choose between the following five options:

Back to main menu Back to current page menu and content View current page breadcrumb Back to site search Continue to page footer content