PHEROMONE-BASED MONITORING OF Pseudococcus maritimus AND INTRA AND INTERSPECIFIC VECTOR EFFICIENCY OF Parthenolecanium corni AND Pseudococcus maritimus AMONG AND BETWEEN Vitis x labruscana L. AND Vitis vinifera By BRIAN WILLIAM BAHDER A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY WASHINGTON STATE UNIVERSITY Department of Entomology MAY 2013 © Copyright by BRIAN WILLIAM BAHDER, 2013 All Rights Reserved © Copyright by BRIAN WILLIAM BAHDER, 2013 All Rights Reserved To the Faculty of Washington State University: The members of the Committee appointed to examine the dissertation of BRIAN WILLIAM BAHDER find it satisfactory and recommend that it be accepted. Douglas B. Walsh, Ph.D., Chair Naidu A. Rayapati, Ph.D. David R. Horton, Ph.D. ii ACKNOWLEDGEMENTS I would like to thank Dr. Douglas B. Walsh for giving me this opportunity and allowing me to attain the level of knowledge and training that I have obtained. I would like to thank Dr. Naidu A. Rayapati for allowing me to work in his laboratory so that I could expand my knowledge and base and receive invaluable training in a new field of research. I thank my committee members Dr. Keith Pike and Dr. David Horton in their critical review of my manuscript. I would like to thank Dr. Olufemi Alabi, Dr. Sridhar Jarugula, and Sudarsana Poojari for teaching my all of the molecular techniques needed for achieving our objectives. I would also like to thank all of my friends in Delaware, Florida, and Washington who provided support, both intellectual and personal. I would like to thank my family; mom, dad, Jaime, and Michelle for helping me get to where I am. Finally I would like to thank my wife, Luz Denia Bahder for all of her love and support, making this journey much smoother and much more valuable. iii PHEROMONE-BASED MONITORING OF Pseudococcus maritimus AND INTRA AND INTERSPECIFIC VECTOR EFFICIENCY OF Parthenolecanium corni AND Pseudococcus maritimus AMONG AND BETWEEN Vitis x labruscana L. AND Vitis vinifera Abstract By Brian William Bahder, Ph.D. Washington State University May 2013 Chair: Douglas B. Walsh Grapes have a major economic impact on the state of Washington, which is the number one producer of Concord juice grapes in the United States and the second largest producer of wine grapes in the United States, after California. Due to the importance of grapes to Washington State, there is a very low tolerance to pests and diseases. The most devastating viral disease of grapes, grapevine leafroll disease, was found in Washington State in 2005 and due to the presence of natural vectors Pseudococcus maritimus and Parthenolecanium corni of the associated viruses, a more rapid means of detection and better understanding of the epidemiology of the disease is necessary. The primary objectives of this research are to develop a rapid, cost-effective monitoring program for Ps. maritimus using its sex pheromone and to determine if Pa. corni and Ps. maritimus are capable of transmitting the viruses associated with grapevine leafroll disease between two different species of grape. To establish an economical means to monitor for Ps. maritimus, three different trapping densities were deployed in various vineyards; one, four, and eight pheromone- baited traps per 12.14 hectares of vineyards. Traps were collected weekly in 2010 and iv 2011 and adult males were counted. In this project we were able to demonstrate that one trap per 12.14 ha of vineyard was adequate to detect populations of Ps. maritimus so as to make appropriate management decisions. To determine if both vector species were capable of transmitting this virus between species, a total of 90 bioassays were conducted under greenhouse conditions where first instars of each species was allowed a one week access period on a virus infected plant and were then transferred to a virus free recipient plant for a one week inoculation period. With this research, we were able to demonstrate that both species of vector were capable of transmitting this virus between species of grape under greenhouse conditions and that Ps. maritimus appears to be a more efficient vector than Pa. corni. These results will be important in further understanding the epidemiology of grapevine leafroll disease and how to monitor and control its vectors. v TABLE OF CONTENTS ACKNOWLEDGEMENTS .............................................................................................. iii ABSTRACT ...................................................................................................................... iv LIST OF TABLES .......................................................................................................... viii LIST OF FIGURES .......................................................................................................... ix DEDICATION ................................................................................................................. xii CHAPTER 1. INTRODUCTION .........................................................................................................1 History and Economics of Wine and Grapes in Washington State .......................1 Grapevine Leafroll Disease and Associated Viruses .............................................2 Vector and Pathogen Interactions ...........................................................................5 Grapevine Leafroll Disease in Washington State ..................................................7 Insect Vectors of Grapevine Leafroll Disease ........................................................9 References ............................................................................................................14 2. PHEROMONE-BASED MONITORING OF PSEUDOCOCCUS MARITIMUS (HEMIPTERA: PSEUDOCOCCIDAE) POPULATIONS IN CONCORD GRAPE VINEYARDS ................................................................................................................21 Introduction ...........................................................................................................21 Materials and Methods ...........................................................................................24 Field Test Sites ...........................................................................................24 Pheromone-Baited Traps ...........................................................................24 Trap Density ..............................................................................................24 Data Collection and Analysis ....................................................................25 Sample Size ...............................................................................................26 vi TABLE OF CONTENTS Results ...................................................................................................................27 Seasonal Phenology ..................................................................................27 Trap Density Comparisons ........................................................................28 Sample Size ...............................................................................................30 Mealybug species ......................................................................................35 Discussion ..............................................................................................................35 References ..............................................................................................................42 3. PSEUDOCOCCUS MARITIMUS (HEMIPTERA: PSEUDOCOCCIDAE) AND PARTHENOLECANIUM CORNI (HEMIPTERA: COCCIDAE) ARE CAPABLE OF TRANSMITTING GRAPEVINE LEAFROLL-ASSOCIATED VIRUS 3 BETWEEN VITIS x LABRUSCANA L. AND VITIS VINIFERA .....................................................50 Introduction ...........................................................................................................50 Materials and Methods ..........................................................................................53 Insect Colonies and Plant Material ...........................................................53 Identification of Pa. corni and Ps. maritimus ............................................54 Transmission Bioassays ............................................................................56 Data Analysis ............................................................................................57 Results ...................................................................................................................58 Species Identity .........................................................................................58 Transmission Bioassays ............................................................................58 Discussion .............................................................................................................60 References ..............................................................................................................66 vii LIST OF TABLES CHAPTER 1 1-1. Modes of Transmission of insect vectors with piercing-sucking mouthparts that transmit viruses ....................................................................................................6 1-2. All species of virus detected in Washington State vineyards to date ...................8 1-3. Species of GLRaVs and their associated vectors ...............................................11 CHAPTER 3 3-1. Primer sequences for virus and insect verification ...............................................55