Response to Blossey and Casagrande: Ecological and evolutionary processes make host specificity at the subspecies level exceedingly unlikely

Abstract

We agree with Blossey and Casagrande (2016) that absolute host-specificity is a necessity for successful biological control of invasive plants without unintended consequences for native species. However, inclusion of non-target native species in the diet of a biological control agent is a relatively common phenomenon with native congeners of the target plant species at greatest risk (Pemberton 2000).