Birch Leafminers

This small wasp (Lathrolestes luteolator) has drastically reduced the birch leafminer problem in Edmonton.


Since the 1970s, three species of sawflies (Fenusa pusilla, Profenusa thomsoni, Heterarthrus nemoratus) introduced from Europe were responsible for the premature browning of birch tree leaves in Edmonton. These species are now largely controlled by naturally occurring parasitoid wasps.

There is a more newly introduced species that seems to be on the rise: Scolioneura betuleti. The City of Edmonton will be monitoring this new leafminer to identify beneficial insects that may be making use of this sawfly as a host, which will support control efforts.