Is host‐specificity of weed biological control agents likely to evolve rapidly following establishment?

Abstract

Here we review the evidence for rapid evolution in the host-specificity of herbivores, looking particularly at evidence from weed biological control, and discuss implications for the practice of weed biological control. We approach the problem from the perspective of evolutionary constraints inferred by host-specificity itself and discuss whether the type and degree of host-specificity predisposes a herbivore to evolutionary change. This approach has the added advantage that host-specificity is relatively easily described and quantified. Rapid evolution also requires genetic variation and an ecological context in which directional selection can occur