EVALUATION OF THE APHIDIUS COLEMANI- RHOPALOSIPHUM PADI BANKER PLANT SYSTEM IN GREENHOUSE BIOLOGICAL CONTROL By TRACEY LEE PAYTON MILLER Bachelor of Science in Horticulture Oklahoma State University Stillwater, Oklahoma 2004 Master of Science in Entomology Oklahoma State University Stillwater, Oklahoma 2007 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY May 2018 EVALUATION OF THE APHIDIUS COLEMANI- RHOPALOSIPHUM PADI BANKER PLANT SYSTEM IN GREENHOUSE BIOLOGICAL CONTROL Dissertation Approved: Dr. Eric J. Rebek Dissertation Advisor Dr. Steve Frank Dr. Mike Schnelle Dr. Kris Giles ii ACKNOWLEDGEMENTS I thank my Advisor, Dr. Eric Rebek, who is a wonderful mentor and friend. He was always available and patient when I had questions or problems. He provided positive, creative criticism and was continually encouraging. To him I am extremely grateful for the opportunity to fulfill my dream of a Ph.D. Thank you. I thank my committee members, Drs. Steve Frank, Kris Giles, and Mike Schnelle. Dr. Giles taught and challenged me throughout my entomological education at Oklahoma State University (OSU). Dr. Frank was an invaluable resource when I had questions about banker plants. Dr. Schnelle was humorous and provided sound advice when working with greenhouse producers, as well as introducing me to important horticulturists. I greatly appreciate Dr. Mark Payton for helping to run and make sense of the statistics in my research. None of this research would be possible without my generous cooperators and donors. I sincerely thank Bear Creek Farms, Stillwater, OK, OSU-Oklahoma City (OKC), and Scissortail Farms, Tulsa, OK. Vicki and Terry Stamback at Bear Creek, and Haldor Howard and Denise Welker at OSU-OKC were a pleasure to work with and I appreciate their openness to my research. I also thank my pesticide donors: Bayer, Dow AgroSciences, Nufarm, OHP, SePro, and Syngenta. Peppers were generously grown by Sunrise Acres in Blanchard, OK and Prairie Wind Nursery in Norman, OK. I thank the all the wonderful faculty and staff in the Department of Entomology iii Acknowledgements reflect the views of the author and are not endorsed by committee members or Oklahoma State University. and Plant Pathology at OSU. I’m grateful to all the students who helped with research projects. My funding was provided by the National Institute of Food and Agriculture, with help from Dr. Tom Royer. Thank you. Finally, I must thank numerous friends, family, and colleagues for their unending encouragement. A very special thanks to Dr. Trisha Dubie who provided invaluable advice as a friend and colleague, and was eager to celebrate every milestone. Finally, I thank my loving husband Alex “Felix” Miller for his unending encouragement, love, support, and help potting thousands of ‘black pearl’ peppers. He was my personal cheerleader who has seen me through two graduate degrees. iv Acknowledgements reflect the views of the author and are not endorsed by committee members or Oklahoma State University. Name: TRACEY LEE PAYTON MILLER Date of Degree: March, 2018 Title of Study: EVALUATION OF THE APHIDIUS COLEMANI-RHOPALOSIPHUM PADI BANKER PLANT SYSTEM IN GREENHOUSE BIOLOGICAL CONTROL Major Field: ENTOMOLOGY Banker plants are mobile habitats that provide alternate hosts or food for commercially available natural enemies. As a biological control strategy, banker plants offer a novel non-chemical approach to managing commonly encountered pests in the greenhouse. Most banker plants that target aphids consist of a graminaceous plant, a non- pest cereal grain aphid, and a parasitoid that attacks both the non-pest and pest aphids occurring on crop plants. Use of banker plants may provide more effective, long-term pest control than pesticide applications, but both can be combined. Banker plant systems have been used commercially in areas of the United States, Canada, Europe, and Asia. One of my goals was to ascertain if banker plants are a viable aphid pest management technique in the southwestern United States. The following study is an overview of the history of biological control in enclosed environments, the Aphidius colemani- Rhopalosiphum padi banker plant system in Oklahoma, pesticides compatible with A. colemani natural enemies, the costs and benefits of the Aphidius colemani- Rhopalosiphum padi system to manage aphid pests, and alternative species of grasses for potential use as banker plants. v TABLE OF CONTENTS Chapter Page I. INTRODUCTION ......................................................................................................1 Objectives ................................................................................................................2 II. REVIEW OF LITERATURE....................................................................................3 Biological Control in Greenhouses ..........................................................................3 The Banker Plant Method ........................................................................................8 Aphidius colemani (Viereck) and Rhopalosiphum padi (L.) Banker Plant System ......................................................................................................................9 Green Peach Aphid, Myzus persicae .....................................................................14 Pesticide Compatibility with Banker Plants ..........................................................16 Greenhouse Production and Variety Trials ............................................................20 Literature Cited ......................................................................................................26 III. THE APHIDIUS COLEMANI-RHOPALOSIPHUM PADI BANKER PLANT SYSTEM IN OKLAHOMA GREENHOUSES ....................................................43 Abstract ..................................................................................................................43 Introduction ............................................................................................................44 Materials and Methods ...........................................................................................45 Aphid Colonies ................................................................................................47 Data Collection ................................................................................................49 Results and Discussion ..........................................................................................51 Relative Humidity and Temperature Correlation ...........................................55 Benefits of Banker Plants and Cost Analysis .................................................59 Literature Cited ......................................................................................................63 vi Chapter Page IV. PESTICIDE COMPATIBLITY WITH APHIDIUS COLEMANI PARASITOIDS FOR BIOLOGICAL CONTROL OF MYZUS PERSICAE ...................................88 Abstract ..................................................................................................................88 Introduction ............................................................................................................89 Materials and Methods ...........................................................................................90 Foliar-Applied Pesticides .................................................................................90 Systemic Pesticides ..........................................................................................92 Results and Discussion ..........................................................................................93 Foliar-applied Insecticide Compatibility .........................................................93 Systemic Pesticide Compatibility ....................................................................97 Literature Cited ......................................................................................................99 V. VARIETY TRIAL OF POACEAE SPECIES FOR BANKER PLANT POTENTIAL IN SOUTHWESTERN GREENHOUSES ..........................................................109 Abstract ................................................................................................................109 Introduction ..........................................................................................................110 Materials and Methods .........................................................................................111 Results and Discussion ........................................................................................113 Literature Cited ....................................................................................................116 vii LIST OF TABLES Table Page CHAPTER II Table 1: Canadian and U.S. biological control suppliers..........................................42 CHAPTER III Table 1. Trial dates and sites for study .....................................................................67 Table 2. Mean number of M. persicae between augmentative and banker plant treatments in Trial 1 ...................................................................................68 Table 3. Mean number of M. persicae between augmentative and banker plant treatments in Trial 2 ...................................................................................69 Table 4. Mean number of aphid mummies between augmentative and banker plant treatments