HEALTH & BIOSECURITY Prioritizing Weed Targets for Biological Control in the Western USA Report on Workshop 1 (Weed Impacts & Desired Management Goals) Report on Workshop 2 (Feasibility & Likelihood of Biological Control) S. Raghu and Louise Morin May 2017 Client: USDA‐ARS Western Regional Research Center Client Contact: Dr Paul Pratt (Exotic & Invasive Weeds Research Unit) Prioritizing Weed Targets for Biological Control in the Western USA | i Sources of photos on cover page Dan Tenaglia (http://www.missouriplants.com); Colorado State University; La Plata Co (Colorado); SEINet (http://swbiodiversity.org/seinet/index.php); North Carolina State University; Washington State Noxious Weed Control Board; Wikimedia Commons Citation Raghu, S and Morin, L (2018) Prioritising Weed Targets for Biological Control in the Western USA. CSIRO, Australia. Copyright © Commonwealth Scientific and Industrial Research Organisation 2018. To the extent permitted by law, all rights are reserved and no part of this publication covered by copyright may be reproduced or copied in any form or by any means except with the written permission of CSIRO. Important disclaimer CSIRO advises that the information contained in this publication comprises general statements based on scientific research. The reader is advised and needs to be aware that such information may be incomplete or unable to be used in any specific situation. No reliance or actions must therefore be made on that information without seeking prior expert professional, scientific and technical advice. To the extent permitted by law, CSIRO (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it. ii | Prioritizing Weed Targets for Biological Control in the Western USA Contents Acknowledgments ........................................................................................................................... iv Executive Summary ..........................................................................................................................v 1 Introduction ........................................................................................................................ 6 1.1 Background ............................................................................................................ 6 1.2 Project scope ......................................................................................................... 6 2 Methods .............................................................................................................................. 8 2.1 Initial consultation ................................................................................................. 8 2.2 Workshop 1 (Weed Impacts & Desired Management Goals) ............................. 10 2.3 Workshop 2 (Feasibility of Biological Control & Likelihood of Success) ............. 12 2.4 Integrating Weed Impacts and Biological Control Prospects .............................. 16 3 Results & Discussion ......................................................................................................... 17 3.1 Initial consultation ............................................................................................... 17 3.2 Workshops ........................................................................................................... 19 3.3 Integrating Weed Impacts and Biological Control Prospects .............................. 21 4 Conclusions ....................................................................................................................... 23 5 References ........................................................................................................................ 24 6 Appendices ....................................................................................................................... 25 Appendix 1. the structured assessment of feasibility of biological control and likelihood of success of biological control on weeds of the western USA ........................................ 25 Appendix 2. Detailed dossiers on the structured assessment of feasibility of biological control and likelihood of success of biological control on weeds of the western USA ... 67 Appendix 3. Notes taken during presentations on each weed by participants who performed the assessments (Appendix 1) during Workshop 2, and the resultant group review 173 Appendix 4. Weeds provided for this prioritization exercise that were only present on the lists of one or two states in the western USA. ......................................................... 184 Prioritizing Weed Targets for Biological Control in the Western USA | iii Acknowledgments We thank the state weed management coordinators, survey respondents and participants of Workshop 1, which included representatives from Arizona, California, Colorado, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington and Wyoming. The following people attended Workshop 1: Jennifer Andreas; LeRoy Brady; Paul Brusven; Dave Burch; Lara Duran; Aaron Foster; Sean Gephart; Greg Haubrich; Dean Kelch; Alan Martinson; Mark Porter; Paul Pratt; Carol Randall; Rachel Winston; Tom Woolf. Workshop 2 was attended by biological control experts with expertise in developing weed biological control programs in the western USA. The following people attended Workshop 2: Jennifer Andreas; Dan Bean; Massimo Cristofaro; John Gaskin; Jeff Littlefield; Joey Milan; Patrick Moran; Andrew Norton; Mike Pitcairn; Paul Pratt; Carol Randall; Brian Rector; Mark Schwarzländer; Sharlene Sing; Lincoln Smith; Sonja Stutz; David Thompson; Natalie West; Philip Weyl. Hariet Hinz and Urs Schaffner were unable to attend the workshop but provided their inputs in writing in advance of the workshop. The survey undertaken as part of this project was approved by CSIRO’s Social Science Human Research Ethics Committee in accordance with the National Statement on Ethical Conduct in Human Research (2007). This project was funded, in part, by the USDA‐ARS’ Exotic and Invasive Weeds Research Unit by Dr Paul Pratt. iv | Prioritizing Weed Targets for Biological Control in the Western USA Executive Summary Invasive weeds represent significant threats and costs to production (rangelands, croplands) and natural landscapes. Classical biological control programs can yield substantial benefits in the management of invasive weeds and historical programs have high benefit‐cost ratios. However, these programs are typically long‐term investments with significant up‐front costs to develop safe agents, the efficacy of which can be uncertain. Given that resources to manage weeds in any jurisdiction are often limited, there is a need to better prioritize weed targets for biological control to facilitate their management in the most cost‐effective manner possible. Improving on previous prioritization processes developed and applied for weed classical biological control, we have developed a structured framework that achieves this in a consultative and transparent manner. In this study we applied this framework to assist the USDA‐ARS’s Exotic & Invasive Weeds Research Unit to prioritise weeds of ten western states of the continental USA as targets for biological control. Through a combination of online surveys and a face‐to‐face workshop with land managers, the first and second stages elicited, captured and characterized the relative importance of a weed, its impacts and desirable management goals. These stages captured the knowledge of weed scientists and land managers to ensure that those investigating and managing impacts on the ground arrive at a list of weeds for which biological control may be desirable. The third stage subsequently assessed the feasibility of biological control and the likelihood of achieving the desired management goals for these weeds. This stage takes advantage of the collective experience of biological control scientists and practitioners to classify the prospects of biological control contributing to successfully achieving the management goals. The focus of this prioritisation study was on weeds of importance to three or more states (i.e. a regional prioritisation). The resultant matrix of weed impact by biocontrol prospects (appended below) prioritised weeds that have been historical targets (suggesting that their biocontrol may be inadequate or insufficiently widespread), also identified prospective targets for future biocontrol research. This matrix needs to be read in conjunction with detailed annotations elicited from experts on the various weeds and their biological control (provided as Appendices to this report). Prioritizing Weed Targets for Biological Control in the Western USA | v 1 Introduction 1.1 Background Invasive weeds represent significant threats and costs to production (rangelands, croplands) and natural landscapes. Classical biological control can be a powerful tool in the management of invasive weeds and historical investments in biological control programs have returned significant environmental and economic benefits (Page and Lacey 2006; van Driesche et al. 2010). However, these programs are typically long‐term investments with significant up‐front costs to develop safe agents, the future efficacy of which can be uncertain (Briese 2004; van Driesche et al. 2016). Given that resources