United States Department of Agriculture Biology and Biological Control of Purple Loosestrife Second Edition Forest Forest Health Technology FHTET-2015-3 Service Enterprise Team September 2015 The Forest Health Technology Enterprise Team (FHTET) was created in 1995 by the Deputy Chief for State and Private Forestry, USDA Forest Service, to develop and deliver technologies to protect and improve the health of American forests. This book was published by FHTET as part of the technology transfer series. This publication is available online at: http://www.fs.fed.us/foresthealth/technology/ This publication/database reports research involving pesticides. CAUTION: PESTICIDES It does not contain recommendations for their use, nor does it imply that the uses discussed here have been registered. All uses of pesticides must be registered by appropriate State and/or Federal agencies before they can be recommended. CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and fish or other wildlife—if they are not handled or applied properly. Use all pesticides selectively and carefully. Follow recommended practices for the disposal of surplus pesticides and pesticide containers. The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the U.S. Department of Agriculture or the Forest Service of any product or service to the exclusion of others that may be suitable. Cover Photo Credits Cover photos (clockwise from top left): adult Galerucella calmariensis (David Cappaert, Michigan State University, bugwood.org); purple loosestrife flower (Linda Wilson, University of Idaho); adult Nanophyes marmoratus (Mark Schwarzländer, University of Idaho); adult Hylobius transversovittatus (Jennifer Andreas, Washington State University Extension) In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating in or administering USDA programs are prohibited from discriminating based on race, color, national origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, marital status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all bases apply to all programs). 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Submit your completed form or letter to USDA by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil Rights, 1400 Independence Avenue, SW, Washington, D.C. 20250- 9410; (2) fax: (202) 690-7442; or (3) email: [email protected] . Federal Recycling Program Printed on recycled paper Biology and Biological Control of Purple Loosestrife Second Edition Bernd Blossey, Carol Bell Randall, and Mark Schwarzländer For additional copies of this publication, contact: Mark Schwarzländer Richard Reardon Carol Bell Randall Department of Plant, Soil USDA Forest Service, FHTET Forest Health Protection and Entomological Sciences 180 Canfield Street USDA Forest Service University of Idaho Morgantown, WV 26505 Coeur d’Alene, ID 83814 Moscow, ID 83844 (304) 285-1566 (208) 769-3051 (208) 885-9319 [email protected] [email protected] [email protected] This publication is available online at http://www.fs.fed.us/foresthealth/technology/ Authors Bernd Blossey Department of Natural Resources Cornell University Ithaca, New York [email protected] Carol Bell Randall Forest Health Protection USDA Forest Service Coeur d’Alene, ID [email protected] Mark Schwarzländer Department of Plant, Soil, and Entomological Sciences University of Idaho Moscow, ID [email protected] Original 2004 version by Linda M. Wilson, Mark Schwarzländer, Bernd Blossey, and Carol Bell Randall Acknowledgments Linda Wilson (University of Idaho), Gary Piper (Washington State University), Eric Coombs (Oregon Department of Agriculture), Douglas Landis (Michigan State University), and Robert Wiedenmann (University of Illinois/Illinois Natural History Survey) contributed to the first edition of this manual, and many of their contributions have been retained in this revision. The content for this new edition was compiled by Rachel Winston (MIA Consulting), and the layout was designed by Wendy W. Harding. We would like to thank all of the photographers who granted permission for the use of photos. We also extend our gratitude to Richard Reardon (Forest Service-Forest Health Technology Enterprise Team or FHTET) for producing this guide. New to This Edition This second edition of the Biology and Biological Control of Purple Loosestrife has been updated to reflect developments in purple loosestrife biological control since 2004, and expanded to include more information on the history, process, safety, and application of classical biological control of weeds as a component of an integrated weed management program. New images have been added to better illustrate identifying characteristics of purple loosestrife, biocontrol agent life stages, and biocontrol agent damage to purple loosestrife plants. Biocontrol agents life stages (eggs, larvae, pupae, adults), life cycle, habitat preference, damage, and current status and availability are described in more detail and in tabular form to facilitateidentification and comparison of biocontrol agents’ life cycles and damage. The chapter on biocontrol implementation has been expanded to provide the reader with resources for successfully planning and implementing a purple loosestrife biocontrol program. A new chapter on integrated purple loosestrife management has been added which describes other management tools for purple loosestrife (including physical, cultural, and chemical control) and when and how best to integrate biological control with other management tools as part of a purple loosestrife integrated weed management program. Contents Chapter 1: Introduction . 1 Overview . 1 Classical Biological Control of Weeds . 3 Code of Best Practices for Classical Biological Control of Weeds . 5 Biological Control of Purple Loosestrife . 6 Integrated Weed Management . 7 Is Biological Control of Purple Loosestrife Right For You? . 7 About This Manual . 8 Chapter 2: Getting to Know Purple Loosestrife . 10 Taxonomy and Related Species . 10 Purple Loosestrife . 13 Classification . 13 Description . 14 Biology and Ecology . 17 Habitat . 17 Distribution . 17 Comments . 18 Commonly Confused Species . 19 Chapter 3: Biology of Purple Loosestrife Biocontrol Agents . 20 Basic Insect Biology . 20 Purple Loosestrife Biological Control Insects . .21 Galerucella calmariensis & G. pusilla . 23 Black-margined loosestrife beetle & Golden loosestrife beetle Hylobius transversovittatus . 27 Loosestrife root weevil Nanophyes marmoratus . 30 Loosestrife flower weevil Comparison Tables . 34 Chapter 4: Elements of a Purple Loosestrife Biological Control Program . .36 Before You Begin . 36 Determining the Scope of the Problem . .36 Defining Goals and Objectives . 36 Understanding Purple Loosestrife Management Options . 38 Developing, Implementing, and Managing a Purple Loosestrife Biological Control Program . 38 Selecting Biological Control Agent Release Sites . 38 Establish goals for your release site . 38 Determine site characteristics . 39 Note land use and disturbance factors . 40 Survey for presence of biological control agents . .40 Record ownership and access . 41 Obtaining and Releasing Purple Loosestrife Biological Control Agents . 42 Factors to consider when looking for sources of biological control agents . 42 Contents (continued) Collecting Purple Loosestrife Biological Control Agents . .44 Collection methods . 44 Aspirating . 45 Sweep netting. 45 Tap & Funnel . 46 Methods by species . 46 Leaf beetles (Galerucella spp.) . 46 Flower weevil (Nanophyes marmoratus) . 47 Root weevil (Hylobius transversovittatus) . .47 Release Containers for Purple Loosestrife Biological Control Agents . 47 Transporting Purple Loosestrife Biological Control Agents . 48 Keep the containers cool at all times . .48 Transporting short distances . 49 Shipping long distances . 49 Other factors to consider . 50 Common packaging mistakes . 51 Rearing Purple Loosestrife Biological Control Agents . .51 General Galerucella and Nanophyes rearing guidelines . 51 Obtain plants . 51 Cover plants. 52 Introduce beetles . 52 Transport beetles after rearing . 53 Overwintering potted plants and beetles . .53 Rearing Hylobius transversovittatus on an artificial diet. 54 Advantages of an artificial