The discovery and quantification of significant non-target ecological effects of Rhinocyllus conicus on native species in the northcentral USA provides the opportunity to experimentally evaluate factors that might help predict non-target host plant use, magnitude of direct impact with transference, and indirect effects mediated by trophic interactions. The relevance for biocontrol risk assessme...

A laboratory study investigated development of teratocytes derived from the parasitoid Microctonus aethiopoides Loan in the natural host, Sitona discoideus Gyllenhal, and in three novel hosts, the introduced weed biological control agent Rhinocyllus conicus (Froehlich), and two New Zealand native species Nicaeana cervina Broun and Irenimus stolidus Broun. Weevils were exposed to parasitoids and...

Landscape change has great, yet infrequently measured, potential to influence the susceptibility of natural systems to invasive species impacts. We quantified attack by an invasive biological control weevil (Rhinocyllus conicus) on native thistles in relation to two types of landscape change: agricultural intensification and invasion by an exotic thistle, Carduus nutans, the original target of ...

Studies of biogeographic variation in species abundances are fundamental to understanding and predicting the impacts of invasive exotic species. We quantified the abundance of the introduced and now invasive biocontrol weevil, Rhinocyllus conicus, on a newly adopted native host plant, Cirsium canescens (Platte thistle), across the plant's distributional range. We used regression and structural ...

The problem of invasive species has reignited interest in biological control as a management tool. Classical biological control involves deliberate release of exotic natural enemies into new environments in an attempt to limit the density of an invasive species. Persistent, sustained limitation of invasive species by coevolved natural enemies is a seductive concept. Evidence now suggests, howev...

A review of information on the release of Rhinocyllus conicus to control of Carduus spp. thistles in North America suggests at least 8 lessons for future biological control efforts. These lessons include the need for: 1) better a priori quantification of the occurrence and ecological effects of the weed; 2) improved incorporation of ecological criteria to supplement the phylogenetic information...

Insect-mediated indirect interactions between native plant species recently have been shown to be important determinants of plant performance in a number of ecological communities. However, the potential indirect effects of exotic plant invasion on native plant species are not well understood. We examined whether the presence or proximity of the targeted exotic weed, musk thistle, influences th...