Both insects are native to Europe, but the sawfly has been accidentally introduced into North America where it has become established.

The wasp parasitises the larvae and has been released in North America as part of a biological control programme for the sawfly.

Further work was undertaken between 2002 and 2015 to spread the parasite throughout eastern North America.

This was done by collecting fallen fruitlets of apple trees in infected orchards in the Frelighsburg area, and scattering them in orchards in other parts of Quebec, Ontario, Nova Scotia and New Hampshire.

As a result of this introduction, the wasp became established in three other parts of Quebec and in Hilton in Ontario.