Surveillance networks for beneficial insects: Can natural habitats serve as insect reservoirs and do they contribute to yield?

Researcher: Dr. Paul Galpern, University of Calgary

Project Code: CARP CCC 2016.21

Final Report: August 2020

Summary: Canola is a dominant flowering crop on the prairie landscape, yet the relationships between canola productivity, insect biodiversity and landscape features are poorly understood. Canola fields can provide a variety of resources that are beneficial to wild pollinator abundance and species richness. While the effects of pollinators on canola have been well documented, the yield benefits of pest control by natural enemies were not previously studied. Specifically, there is lack of understanding on the reciprocal impact of all beneficial insects on canola yield from services provide by wild pollinators and natural enemies of insect pests, and of canola on beneficial insects. A four-year study was conducted by researchers at the University of Calgary to measure how the proximity to specific natural habitat features is associated with (1) beneficial insect abundance and diversity; and (2) canola yield.

The network identified a total of 157,407 arthropods of 418 species including approximately 375 species of wild bees, 42 species of most common spiders and 57 species of ground beetles (in the family Carabidae) in Alberta canola fields. This sampling has developed a geographically-extensive database on the distribution, abundance and diversity of beneficial arthropods found in Canadian prairie croplands. Furthermore, analyses of the network data showed that non-crop areas such as wetland margins, field margins and pivot corners are likely to serve as a source as well as a destination for beneficial arthropods at different times of the season. Wetland margins, in particular, may be hotspots for beneficial arthropods, and these organisms spill over into canola fields. Finally, the network collected evidence that beneficial arthropods found in non-crop areas are available to provide pest control and pollination services to canola growers. A correlational study of 60 million seeded acres of yield data in Alberta (2012 to 2017) obtained from Agriculture Financial Services Corporation (AFSC) showed that counties in Alberta where fields have more non-crop areas also have slightly higher canola yields (Galpern et al, 2020). This provides preliminary and indirect evidence that non-crop areas can influence canola yield. A pilot study of five fields, that used cages to exclude arthropods from canola plants, also showed that the spill-over of arthropods from non-crop areas may increase canola seed weight (Figure 1). This result is being confirmed with additional field experiments in the second phase of the surveillance network.

Key Messages:
- The surveillance network identified a total of 157,407 arthropods of 418 species from 317 sampled areas in southern and central Alberta.
- Sampling by the surveillance network developed a geographically extensive database on the distribution and abundance of beneficial arthropods found in Canadian prairie croplands.
- Non-crop areas such as wetland margins, field margins and pivot corners were shown to be reservoirs that serve as a source as well as a destination for beneficial arthropods at different times of the season.
- Wetland margins in particular may be hot spots for beneficial insects that spill over into canola fields.
- The research collected evidence that beneficial arthropods found in non-crop areas are available to provide pest control and pollination services to canola growers.

Click the links below to download a short version of the report, the full detailed long version of the report, or the related Canola Digest PDF.

Back to main Research Project Reports page >

Get important canola info delivered to your email. Join our mailing list