Open Collections

Abstract

Species introductions to novel environments can result in economic and ecological damage if those species become invasive, which may be likely with abundant resources and in the absence of co-evolved natural enemies. The invasive strawberry blossom weevil, Anthonomus rubi (Herbst, 1795) (Coleoptera: Curculionidae), lacks co-evolved natural enemies in its introduced range of Southwestern British Columbia, Canada, and feeds upon a variety of crop and non-crop host plants. I conducted surveys, with collaborators from the EU-based Centre for Agriculture and Biosciences International (CABI) to identify potential natural enemies of A. rubi in its native range (Europe) that could be considered for future biological control programs. I also recorded host plant species that supported successful parasitism. Then, in the introduced range, I evaluated the effects of host plant species and bud size on the size of adult A. rubi at emergence, which has been used as a proxy for insect fitness. Surveys in the native range showed A. rubi and its natural enemies develop in a variety of host plant species, with damaged flower buds collected from 13 host plant species in the family Rosaceae over three years. In addition, I identified 12 parasitoid species associated with A. rubi, including seven not previously associated with A. rubi, in its native range. In the introduced range of southwestern BC, Canada, damaged flower buds from introduced blackberry (Rubus armeniacus) supported larger sizes of weevils in comparison with those emerging from cultivated strawberry flower buds. Weevil size was positively correlated with strawberry bud size. Adult weevil size increased throughout the season. Together, these results show the impact host plant traits can have on weevil size. I discuss how this information could be used in the future for the rearing of associated biological controls.