Review Progress in risk assessment for classical biological control B.I.P. Barratt a, * , F.G. Howarth b , T.M. Withers c , J.M. Kean d , G.S. Ridley e a AgResearch Invermay, Biocontrol, Biosecurity and Bioprocessing, Puddle Alley, Mosgiel PB 50034, New Zealand b Bishop Museum, 1525 Bernice St., Honolulu, Hawaii 96817-2704, USA c Forest Biosecurity and Protection, Scion, PB 3020, Rotorua 3046, New Zealand d AgResearch Lincoln, Biocontrol, Biosecurity and Bioprocessing, PB 4749 Christchurch, New Zealand e ERMA New Zealand, P.O. Box 131, Wellington, New Zealand article info Article history: Received 13 October 2008 Accepted 18 February 2009 Available online 9 March 2009 Keywords: Biological control Biosafety Risk assessment Host range testing Modeling Regulation abstract There has been considerable debate on risks associated with biological control, and partly resulting from this, research has addressed a number of questions which have subsequently led to a greater understand- ing of risk assessment and biosafety. Controversy which arose in the 1980s about the environmental safety of biological control initially created considerable tension between biological control practitioners and those concerned about non-target impacts. Several factors have helped to ease this pressure, and a substantial body of research has addressed many of the questions raised. This has led to advances in quar- antine laboratory host range testing to improve our ability to predict post-release impacts. Furthermore, pre- and post-release studies are increasingly involving population models to estimate the population impact of introduced biological control agents rather than simply measuring attack rates. Regulators making decisions about biological control agent introductions work under conditions of considerable uncertainty, but with accumulating data from past introductions to validate earlier decisions, and a robust peer review system for assessing new proposals, there is cause for some optimism that the risks associated with biological control can be better identified and managed in the future. Progress in research and regulation of biological control are discussed with particular reference to Australasia. Ó 2009 Elsevier Inc. All rights reserved. 1. Introduction In this contribution, we summarize recent developments in re- search on biosafety of biological control. We start by discussing briefly the history of research in this area, through a period of con- troversial debate to a realization that the efficacy of biological con- trol as well as the environmental safety of the outcome can benefit considerably from a robust pre-release risk analysis, an ecological approach to the selection of biological control agents and post- release monitoring of target and non-target impacts. We then examine recent research advances in the areas of biological control agent selection and characterization, and provide some detail of current advances in laboratory testing for host range prediction, an area that is central to risk analysis for regulators. We discuss post-release assessments of biocontrol safety, and recent advances in predictive modeling of population impacts of biological control agents. The paper focuses particularly on research that has been carried out in New Zealand and Australia, and we conclude with a section on the regulatory process in New Zealand, and how well this has performed over the first 10 years of its implementation. 2. The biosafety controversy Research on biological control flourished after the publication in 1963 of the book ‘Silent Spring’ (Carson, 1963), which alerted the public to the environmental and human health dangers of pesticide use. In the aftermath of this book demands were made that pesti- cide use be scrutinized and safer alternatives found. In the book, Rachel Carson examined and promoted the use of biological con- trol and other alternative technologies. Biological control was sud- denly seen as the ‘magic bullet’, and it was promoted to the public as a natural and safe alternative to pesticides. The spectacular suc- cesses of biological control were publicized, and the favorable cost- benefit ratio was emphasized. The benefits that were particularly underscored were that biological control is self-perpetuating, self-dispersing and irreversible. These, of course, are the very rea- sons why biocontrol would later come to be challenged, but, during the 1960s and 1970s biological control practitioners became the heroes, and funding was dramatically shifted into research in this area. Prominent scientists strongly advocated for the environmen- tal safety of biological control in comparison with pesticides (DeBach, 1974; Simmonds and Bennett, 1977; Caltagirone and Huffaker, 1980). Doubts about biosafety of biological control had been expressed over a century ago when Perkins (1897) drew attention to the 1049-9644/$ - see front matter Ó 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.biocontrol.2009.02.012 * Corresponding author. Fax: +64 3 489 3739. E-mail address: barbara.barratt@agresearch.co.nz (B.I.P. Barratt). Biological Control 52 (2010) 245–254 Contents lists available at ScienceDirect Biological Control journal homepage: www.elsevier.com/locate/ybcon