Biology and Biological Control of Yellow Starthistle

Abstract

The use of trade, firm, or corporation names in this publication is for information only and does not constitute an endorsement by the U.S. Department of Agriculture. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or marital or family status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at 202-720-2600 (voice and TDD). 202-720-5964 (voice and TDD). USDA is an equal opportunity provider and employer. Federal Recycling Program Printed on recycled paper. T he 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. providing the funds needed to complete and publish this manual. All photographs used in this publication can be accessed and viewed on line. You'll find reference codes (UGA0000000) in the captions for the figures in this publication. INTRODUCTION Overview Yellow starthistle (Centaurea solstitialis L.) is an invasive weed introduced from the Mediterranean region. It predominantly infests rangelands in the western United States. This second edition manual on the biological control of yellow starthistle is intended to give weed and land managers guidelines to develop and successfully establish a starthistle biocontrol program (Fig. 1). In the United States, approximately 18 million acres are infested with yellow starthistle. A highly competitive and invasive weed, yellow starthistle has adapted to a wide range of habitats and environmental conditions, mostly in California, Oregon, Washington and Idaho (see Fig. 4, page 7). A large amount of information is available giving land managers useful tools to manage yellow starthistle by a variety of strategic methods. Chemical, cultural and mechanical methods used to control weeds all apply when managing yellow starthistle. However, most people recognize that yellow starthistle management on a large scale over the landscape requires well-planned, integrated programs that maximize the effective use of all weed management strategies in combination. Among the myriad of weed control approaches to manage yellow starthistle is biological control, a well known and long-established tool in the United States and Canada. There is …