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Ii DEVELOPMENT and IMPROVEMENT of ARTIFICIAL DEVELOPMENT AND IMPROVEMENT OF ARTIFICIAL DIETS FOR LARVAE OF DIABROTICA SPECIES USING MULTIDIMENSIONAL DESIGN SPACE TECHNIQUES ________________________________________________________________ A Dissertation presented to the Faculty of the Graduate School at the University of Missouri-Columbia _______________________________________________________ In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy _____________________________________________________ by MAN P. HUYNH Dr. Thomas A. Coudron, Dissertation Supervisor APRIL 2018 ii The undersigned, appointed by the dean of the Graduate School, have examined the dissertation entitled DEVELOPMENT AND IMPROVEMENT OF ARTIFICIAL DIETS FOR LARVAE OF DIABROTICA SPECIES USING MULTIDIMENSIONAL DESIGN SPACE TECHNIQUES Presented by Man P. Huynh A candidate for the degree of Doctor of Philosophy and hereby certify that, in their opinion, it is worthy of acceptance. ______________________________________________________ Dr. Deborah L. Finke ______________________________________________________ Dr. Thomas A. Coudron ______________________________________________________ Dr. Bruce E. Hibbard ______________________________________________________ Dr. Kevin L. Fritsche ii This dissertation is dedicated to my wife, Van Ho, and my sons, Tri Huynh and Huy Huynh for their love, support, and sacrifices throughout my graduate studies. I am truly thankful for having my beloved family in my life. ACKNOWLEDGEMENTS I would like to thank my advisors Thomas Coudron and Deborah Finke for their invaluable insight, guidance and support over the past four years. I would like to thank Bruce Hibbard and Kevin Fritsche for his helpful advice on my research. I would like to also thank Kent Shelby, Stephen Lapointe, Randall Niedz, Lisa Meihls, Elisa Bernklau, Louis Bjostad, Wade French, Art Schaafsma, and Andrea Hitchon for their collaboration. My research would not have been possible if it weren’t for the tireless efforts of everyone in our corn rootworm group in the USDA laboratories in Columbia, Missouri. I would especially like to thank Julie Barry, James Smith, Michelle Gregory, Dalton Ludwick, Adriano Pereira, Emily Harrington, Zixiao Zhao, and Brock Andreasen for the many of things they have helped me with my experiments. I would also like to thank Alexander Brittani, Joseph Larose, Kathryn Ingerslew, Jessica Kansman for their help with my graduate studies. I thank the University of Missouri Division of Plant Sciences and the USDA Biological Control of Insects Research Laboratory for making my graduate studies possible. I would like to thank entire Entomology faculty and my fellow graduate students that have been very supportive. I thank the Can Tho University Department of Plant Protection for the support on my graduate studies. Finally, I would like to thank to my family, especially my parents, Danh Huynh and Dao Tran and my parents-in-law, Han Tran and Nghia Ho who have given me their limitless encouragement and support. ii TABLES OF CONTENTS ACKNOWLEDGEMENTS ............................................................................................................ ii LIST OF FIGURES ......................................................................................................................viii LIST OF TABLES .......................................................................................................................... x ABSTRACT .................................................................................................................................. xii CHAPTER I: INTRODUCTION AND LITERATURE REVIEW .................................................1 Introduction ......................................................................................................................................1 Life cycle .........................................................................................................................................1 The development of resistance of corn rootworms ..........................................................................3 Corn rootworm diets ........................................................................................................................5 Diet development methodologies ....................................................................................................9 References ......................................................................................................................................13 CHAPTER II: DIET IMPROVEMENT FOR WESTERN CORN ROOTWORM LARVAE .....21 Abstract ..........................................................................................................................................21 Introduction ....................................................................................................................................22 Materials and methods ...................................................................................................................25 Insects ......................................................................................................................................25 Diet preparation .......................................................................................................................26 Insect bioassays ........................................................................................................................27 Experimental approach ............................................................................................................28 Screening design ......................................................................................................................28 4-component mixture design....................................................................................................29 2-component mixture design for lipid components .................................................................30 Diet optimization .....................................................................................................................30 iii Model evaluation .....................................................................................................................30 Statistical analyses ...................................................................................................................30 Results ............................................................................................................................................32 8-component screening experiment .........................................................................................32 4-component mixture experiment ............................................................................................32 2-component lipid mixture experiment ....................................................................................35 Contamination ..........................................................................................................................35 Model evaluation and diet improvement .................................................................................35 Discussion ......................................................................................................................................36 References ......................................................................................................................................52 CHAPTER III: ISOLATION AND CHARACTERIZATION OF CORN ROOT FACTORS FOR IMPROVED GROWTH OF WESTERN CORN ROOTWORM LARVAE REARED ON ARTIFICIAL DIET .......................................................................................................................56 Abstract ..........................................................................................................................................56 Introduction ....................................................................................................................................57 Materials and methods ...................................................................................................................60 Insects ......................................................................................................................................60 Corn root extraction .................................................................................................................60 Corn root powder .....................................................................................................................61 Diet preparation .......................................................................................................................62 Larval artificial diet bioassays .................................................................................................63 Diet bioassays with corn root extract .......................................................................................64 Diet bioassays with corn root powder as a major nutritional source .......................................64 Diet bioassays with corn root powder from different seeds and suppliers ..............................65 Statistical analyses ...................................................................................................................65 Results ............................................................................................................................................66 iv Diet bioassays with corn root extraction ..................................................................................66
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