Cover crops as a tool for cutworm management

Cover crops provide multiple benefits to farmers including ecosystem services and economic returns, but have been underutilized as a habitat management strategy to enhance the effectiveness of natural enemies by providing additional food resources, such as floral nectar. Cutworms are economically important pests of multiple Canadian field crops, but are difficult to control with insecticides. Biocontrol with native parasitoids may offer a sustainable alternative for pest management. The polyembryonic parasitoid Copidosoma cuproviridis (Encyrtidae) has the potential to control several species of cutworms in Canada. However, their foraging preferences for non-host food items are unknown. In this study we tested the flower colour and odour preferences of C. cuproviridis across nine cover crop species and investigated how these resources affect survival and longevity of the wasp. Results indicate that starved C. cuproviridis were attracted to yellow and Brassicaceae flower odours, particularly from canola and mustard. However, in multiple choice tests, C. cuproviridis significantly preferred camelina over all other flower species tested. Life expectancy was significantly increased over controls when the wasps were provided floral resources. Camelina has known benefits of weed suppression and may also be a used as a habitat management tool for enhancing parasitism of cutworms by C. cuproviridis.