Improving Integrated Crop Management by Conserving Natural Enemies of Insect Pests

Researcher:

Dr. Lloyd Dosdall, Department of Agricultural, Food and Nutritional Science, University of Alberta and Doug Moisey, Canola Council of Canada

Project Code:

CARP 2004-01

Final Report:

March 2007

Summary:

Field studies were undertaken in southern Alberta and Saskatchewan during the 2006 field season to investigate different management strategies for enhancing the effectiveness of natural enemies of cabbage seedpod weevil and diamondback moth in canola. The study showed that the level of parasitism of the cabbage seedpod weevil has increased dramatically in recent years, and the hymenopteran wasp, Diadegma insulare, is capable of causing significant reductions in diamondback moth populations. Canola growers in regions infested with damaging infestations of cabbage seedpod weevil should maintain recommended seeding rates 2.5 to 4.5 lb/acre (3 to 5 kg/ha) for optimal yields and consistent times to crop maturity. However, early seeding (late April) predisposes the crop to greater attack by the cabbage seedpod weevil and should be avoided.