Assessing safety of biological control introductions.

Abstract

Biological control is an important component of pest management systems. It was generally considered safe and sustainable until the validity of this consensus was challenged by researchers who pointed out that there was a lack of study, and hence evidence, to support it and provided examples of non-target impacts. Biosafety of biological control subsequently received considerable attention from both biocontrol practitioners and regulators. Many countries now have legislation in place, which is focused on risk assessment for biological control and protecting native and valued biota and the environment from potential adverse impacts. This review summarizes the biosafety debate and characterizes the direct and indirect risks of biological control mainly for weeds and insect pests. During a biological control programme, there are several ways in which aspects of biosafety can be considered and addressed: exploration in the native range of the target species; from literature and knowledge of the biological control agent and host; experience from use of the biological control agent elsewhere; and host-range tests. The value of post-release monitoring and retrospective studies for validation of pre-release predictions is discussed. A poorly studied aspect is analysis of the population impacts of non-target attack by biological control agents. The literature from the last 20-30 years can help define some useful principles by which a risk assessment can be conducted to minimize adverse environmental effects. It has become clear over this period that comprehensive assembly of information and robust quarantine testing to provide a well-structured risk assessment can reduce uncertainty in decision-making in this area.