Biocontrols often also invasive

They seem to be being unintentionally introduced 
the same way their prey is

A samurai wasp lays an egg inside a brown marmorated stink bug egg. The samurai wasp’s offspring will develop inside the pest’s egg and emerge as an adult wasp.  PHOTO: WARREN WONG, SIMON FRASER UNIVERSITY

Regulatory limits to the introduction of biocontrols like parasitic wasps may prove to be a moot point.

They could already be being unintentionally released into Canada along with their prey.

Paul Abram, of Agriculture and Agri-Food Canada, has been looking for native predators for the brown marmorated stink bug, a pest introduced to B.C. in recent years from its natural range in Asia.

At a heavily infested site near Chilliwack he found something unexpected — a non-native natural predator called the samurai wasp that comes from the same region, he wrote recently in the Journal of Hymenoptera Research.

“Classical biological control of invasive pests, where natural enemies are imported and intentionally introduced from a pest’s area of origin, involves years of research to assess risks and benefits of proposed introductions, followed by regulatory approval,” wrote the researchers.

“However, there is increasing recognition that unintentional introductions of natural enemies are probably common, introducing a high level of uncertainty to the regulatory process for biological control.”

The brown marmorated stink bug is highly damaging to a wide range of vegetable and fruit crops, including peaches, apples, pears, soybeans, cherries and raspberries. Infested areas in both the U.S. and Europe also saw the arrival of the samurai wasp amid assessments whether releasing samurai wasps in the wild should be warranted.

Field surveys and extensive analyses are currently underway to track the establishment and biological control impact of the samurai wasp in Canada.

About the author



Stories from our other publications