NATIVE HABITAT RESTORATION IN EASTERN WASHINGTON WINE VINEYARDS AS A PEST MANAGEMENT STRATEGY By KATHARINE DENISE BUCKLEY A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY WASHINGTON STATE UNIVERSITY Department of Entomology MAY 2019 © Copyright by KATHARINE DENISE BUCKLEY, 2019 All Rights Reserved © Copyright by KATHARINE DENISE BUCKLEY, 2019 All Rights Reserved To the Faculty of Washington State University: The members of the Committee appointed to examine the dissertation of KATHARINE DENISE BUCKLEY find it satisfactory and recommend that it be accepted. _______________________________ David James, Ph.D., Chair _______________________________ Elizabeth Beers, Ph.D. _______________________________ Joan Davenport, Ph.D. ii ACKNOWLEDGMENTS I thank Lorraine Seymour and Gerry Lauby for their expertise, their organizational skills, their excellence as sounding boards, and hopefully their ability to pass some of that on to me. I thank Cole Provence and my family who were always supportive. I thank all the people who helped me with my statistics, especially Bernardo Chaves. I thank the computer technician who saved my computer’s data and my life. I thank Michael Aquilino. He knows what he did. Finally, I’d like to thank everyone who served on my committee, as well as Laura Lavine, for their guidance along the way. iii NATIVE HABITAT RESTORATION IN EASTERN WASHINGTON WINE VINEYARDS AS A PEST MANAGEMENT STRATEGY Abstract by Katharine Denise Buckley, Ph.D. Washington State University May 2019 Chair: David James Perennial crop systems such as wine grapes have begun using cover crops and hedgerows to increase beneficial insects and promote sustainable vineyard management in areas such as New Zealand and California. However, in arid wine growing regions such as eastern Washington, cover crops are often hard to grow and prohibitively expensive due to water costs. These studies were designed to determine if native plants, which require little or no irrigation, could be used to increase beneficial insect populations and enhance conservation biological control of vineyard pests in eastern Washington. Vineyards with some form of native habitat restoration in four different grape growing regions of eastern Washington were sampled using yellow sticky traps and leaf samples to monitor beneficial and pest insect numbers. These vineyards were compared with nearby conventional vineyards over a three-year period. Secondary pests such as spider mites were well suppressed in habitat-enhanced vineyards, though the primary pests, leafhoppers, were not. Most beneficial insect groups were found to be more abundant in native habitats than in vineyards, and were iv often significantly more abundant in vineyards with native habitat restoration over conventional vineyards. This indicates that native plants used as cover crops or in refugia patches may be a valuable addition to conservation biological control management strategies in arid areas. A partial cost/benefit analysis was also performed, which showed that habitat restoration may be more expensive in the short term than conventional pest control, although long-term benefits may outweigh costs. In a separate study to determine the best plants to use in habitat restorations, native and naturalized plants were evaluated for attractiveness to beneficial insects using clear plastic sticky traps. Plant attractiveness varied greatly by both insect group and time of year. Some native plants currently used to enhance beneficial insect habitat may not be the best option for growers in central Washington, and others such as sagebrush, Artemisia tridentata , may be far more important than previously realized. v TABLE OF CONTENTS Page ACKNOWLEDGMENTS .................................................................................................. iii ABSTRACT ..................................................................................................................... iv TABLE OF CONTENTS .................................................................................................. vi LIST OF TABLES ............................................................................................................ xi LIST OF FIGURES ......................................................................................................... xv INTRODUCTION ............................................................................................................. 1 References ............................................................................................................... 9 INCIDENCE AND ABUNDANCE OF BENEFICIAL AND PEST ARTHROPODS IN HABITAT-ENHANCED AND CONVENTIONAL VINEYARDS ................................ 18 Introduction ............................................................................................................. 18 Methods .................................................................................................................. 22 Vineyards ......................................................................................................... 22 Sampling .......................................................................................................... 26 Leaf samples .............................................................................................. 26 Yellow sticky traps ..................................................................................... 26 Data Analysis ................................................................................................... 30 Results .................................................................................................................... 30 Grape Leaf Samples ........................................................................................ 30 Yellow Sticky Traps .......................................................................................... 37 Bee Identification ....................................................................................... 50 Discussion .............................................................................................................. 51 References ............................................................................................................. 55 vi BENEFICIAL INSECT ATTRACTION TO NATIVE FLORA IN CENTRAL WASHINGTON ....................................................................................................... 60 Introduction ............................................................................................................. 60 Methods .................................................................................................................. 63 Data Analysis ................................................................................................... 65 Results .................................................................................................................... 67 Discussion .............................................................................................................. 85 References ............................................................................................................. 89 ANALYSIS OF BEST MANAGEMENT PRACTICES .................................................... 94 Introduction ............................................................................................................. 94 Methods .................................................................................................................. 95 Results .................................................................................................................... 97 Discussion ............................................................................................................ 102 References ........................................................................................................... 104 CONCLUSION ............................................................................................................ 107 References ........................................................................................................... 111 SATELLITE MAPS AND PLANT LISTS OF ALL VINEYARDS IN STUDY .................. 112 Columbia Gorge Vineyards ................................................................................... 113 Ancient Lakes Vineyards ...................................................................................... 116 Red Mountain Vineyards....................................................................................... 118 Walla Walla Vineyards .......................................................................................... 121 PESTICIDE RECORDS OF STUDY VINEYARDS ...................................................... 125 Columbia Gorge Vineyards ................................................................................... 125 Dry Hollow ...................................................................................................... 125 vii 2011 ......................................................................................................... 125 2012 ......................................................................................................... 125 2013 ......................................................................................................... 125 Klickitat Canyon .............................................................................................. 126 2011 ........................................................................................................