Wasps released in Ontario to fight emerald ash borer

The federal government has approved the release of tiny, Chinese wasps to fight emerald ash borer in Ontario.
The oobius agrili parasitic wasp is very small and doesn't have a stinger. It lays its eggs within emerald ash borer eggs, killing the host egg. (Houping Liu/Michigan State University)

They're so tiny you can hardly see them but these little wasps may be the answer to saving the ash tree population in Ontario. 

The federal government has approved the controlled release of two nearly identical species of wasp that feed on the eggs and larva of the emerald ash borer. The wasps do not have stingers and are around the size of a piece of sand.

The wasps come from China where they feed off the emerald ash borer.The hope is in time the wasps will put a significant dent in the emerald ash borer population to allow ash trees to survive. 

According to Barry Lyons, a forest entomologist with Natural Resources Canada, the wasps pose almost no threat to humans or our environment, "There is absolutely no potential impact on people or pets or anything other than emerald ash borer."

The wasps, however, are not a quick fix. Lyons says it takes time to build up the population of the wasps before they can be effective,

"This is not a silver bullet, this is not something that happens overnight, it takes a long time to develop. In some areas in Ontario there are not a lot of ash trees that are surviving, so we are predicting that we won't be able to save some of them, but maybe the next generation of ash tree that comes up," he said. 

The larva eating species has already been released in a few areas, but Natural Resources Canada recently began a larger release of both species of wasps. Wasp releases at locations near Tillsonburg, London and Georgetown are planned in the next couple months.  


To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.