A prospective and iterative, ecological and molecular approach to finding safe weed biological control agents

Biological control is often the most cost effective and environmentally sound method of managing widespread environmental weeds. Earlier detection of cryptic species and improved understanding of host-herbivore associations during the initial screening for effective natural enemies should further boost success rates. We formalise a framework for improved prioritisation of biological control agents through the successive feedback between ecological surveys and molecular screening. Incorporating enhanced molecular methods to strengthen hypothesis testing in the initial phases of exploratory research will help prioritise herbivores and regions for subsequent native range surveys, and should more readily uncover unrecognised cryptic species that may otherwise remain hidden. We postulate that this iterative methodology should enhance the environmental safety and cost-benefit ratios of future biological control programs, and this approach should help to elucidate problematic aspects of existing programs.