Author
David J. Ensing
david.ensing@agr.gc.ca
Agriculture and Agri-Food Canada
Summerland
Coauthors
TylerD Nelson, Agriculture and Agri-Food Canada, Summerland, Canada
Chandra E Moffat, Agriculture and Agri-Food Canada, Summerland, Canada
Lauryn Joslin, Queen’s University, Kingston, Canada
Lucas Eckert, McGill University, Montreal, Canada
Marlene, M Kraml, Queen’s University, Kingston, Canada
Christopher G Eckert, Queen’s University, Kingston, Canada
Abstract
Classical biocontrol has had resounding success when prospective control agents have been subject to appropriate prerelease screening. Occasionally however, natural enemies have been reunited with their hosts accidentally. Such adventive agents may provide effective control but have also avoided the careful screening characteristic of modern importation biocontrol programmes. We were studying the invasive mustard, Hesperis matronalis (Dame’s rocket; Brassicaceae), when we discovered rampant seed predation by an unknown seed predator. Using DNA barcoding, we identified this seed predator as Ceutorhynchus inaffectatus (Coleoptera: Curculionidae), a recently (2018) detected species in North America. Comparing potential and realised seed production, we found that seed predation by C. inaffectatus strongly reduces H. matronalis fecundity. C. inaffectatus is expected to be highly host-specific, and the absence of native Hesperidae species in North America suggests the potential for C. inaffectatus as a classical, but adventive, biocontrol agent of H. matronalis. We suggest population genetic research to identify the origin of C. inaffectatus, and host specificity testing before any intentional redistribution of this species for H. matronalis biocontrol. This system is a model for biocontrol prospects with adventive insect herbivore species.
Keywords
adventive
Hesperis matronalis
Ceutorhynchus inaffectatus
fecundity
Highlights
We found unexpected rampant seed predation in the invasive mustard Hesperis matronalis
We identified the recently adventive Ceutorhynchus inaffectatus as the seed predator
Adventive C. inaffectatus is a strong candidate for H. matronalis biocontrol, if host specific