ON ENTOMOPATHOGENIC NEMATODES (RHABDITIDA: STEINERNEMATIDAE AND HETERORHABDITIDAE): A POTENTIAL REARING HOST, BLACK SOLDIER FLY HERMETIA ILLUCENS (L.) (DIPTERA: STRATIOMYIDAE) AND COMPATIBILITY WITH A PREDATORY BEETLE, DALOTIA CORIARIA (KRAATZ) (COLEOPTERA: STAPHYLINIDAE) By Joseph S. Tourtois A THESIS Submitted to Michigan State University in partial fulfillment of the requirments for the degree of Entomology – Master of Science 2014 ABSTRACT ON ENTOMOPATHOGENIC NEMATODES (RHABDITIDA: STEINERNEMATIDAE AND HETERORHABDITIDAE): A POTENTIAL REARING HOST, BLACK SOLDIER FLY HERMETIA ILLUCENS (L.) (DIPTERA: STRATIOMYIDAE) AND COMPATIBILITY WITH A PREDATORY BEETLE, DALOTIA CORIARIA (KRAATZ) (COLEOPTERA: STAPHYLINIDAE) By Joseph S. Tourtois Entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) are soil-dwelling insect parasitic round worms used in augmentative biological control to manage western flower thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) and fungus gnats Bradysis spp. (Diptera: Sciaridae) in greenhouses. Reducing production costs is one way of increasing their adoption by growers. Black soldier fly larvae Hermetia illucens (L.) (Diptera: Stratiomyidae) are evaluated as a potential nematode rearing host. They are not highly susceptible to entomopathogenic nematodes; however, damaging the cuticle before and after infection increases mortality rate, infection rate, nematode entry, and nematode emergence. Even with modification, black soldier fly larvae produce only 10% of the nematodes produced on the standard rearing host Galleria mellonella (L.) (Lepidoptera: Pyralidae). The soil-dwelling predatory rove beetle Dalotia coriaria (Kraatz) (Coleoptera: Staphylinidae) is also used to manage populations of western flower thrips and fungus gnats. Its compatibility with entomopathogenic nematodes is evaluated in a laboratory bioassay. Dalotia coriaria appears to be most compatible with Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae). ACKNOWLEDGEMENTS I thank my major professor Dr. Matthew Grieshop for all of his encouragement and advice over the past four years I spent in the Organic Pest Management Laboratory. I thank my committee members Dr. Zsofia Szendrei and Dr. John Biernbaum for their guidance and approval. I am grateful for Dr. Anne Nielsen, Nate Walton, Pete Nelson, and Dr. David Shapiro-Ilan. They provided support in rearing and working with entomopathogenic nematodes. I appreciate Morgan Burnette, Yvonne Millar, Paul Owen-Smith, Mirijam Garske, and other numerous undergraduate students who spent countless hours counting nematodes, dissecting black soldier fly, and assessing insect mortality. Without their hard work, this project would not have been finished in a timely manner. I also thank Brad Baughman and Emily Pochubay for being excellent role models. Lastly, I need to thank my wife Krys Tourtois for all of her support and understanding. iii TABLE OF CONTENTS LIST OF TABLES ............................................................................................................... VI LIST OF FIGURES ........................................................................................................... VII CHAPTER 1. LITERATURE REVIEW ....................................................................... 1 Biological Control .................................................................................................................. 1 Augmentative Biological Control ..................................................................................... 2 Limitations to application of augmentative Biological control ............................. 4 Economics ............................................................................................................................................... 4 Intraguild Predation ........................................................................................................................... 5 Compatibility with other management strategies ................................................................ 6 Entomopathogenic Nematodes and D. coriaria in Biological control .................. 6 Entomopathogenic Nematodes ........................................................................................ 7 Biology ...................................................................................................................................................... 7 Life Cycle ............................................................................................................................................... 11 Applications ......................................................................................................................................... 12 Rearing ................................................................................................................................................... 13 In vivo rearing .................................................................................................................................. 13 In vitro rearing ................................................................................................................................. 14 Alternative Rearing Host ................................................................................................................ 14 Black Soldier Fly ................................................................................................................. 15 Biology .................................................................................................................................................... 15 History .................................................................................................................................................... 16 Potential Benefits .............................................................................................................................. 16 Potential Limitations ........................................................................................................................ 17 Dalotia coriaria (Kraatz) (Coleoptera: Staphylinidae) .......................................... 18 History .................................................................................................................................................... 18 Biology .................................................................................................................................................... 18 Life Cycle ............................................................................................................................................... 19 Feeding habits ..................................................................................................................................... 19 Rearing ................................................................................................................................................... 20 Compatibility with nematodes ..................................................................................................... 21 Thesis OBjectives ................................................................................................................ 22 CHAPTER 2. EXPLORING THE USE OF BLACK SOLDIER FLY HERMETIA ILLUCENS (L.) (DIPTERA: STRATIOMYIDAE) AS AN IN VIVO ENTOMOPATHOGENIC NEMATODE REARING HOST ........................................................................................................ 23 Introduction ......................................................................................................................... 23 iv Methods and Materials ..................................................................................................... 26 Black Soldier Fly colony .................................................................................................................. 26 Entomopathogenic Nematode colonies ................................................................................... 27 Experiment 1a – black soldier fly susceptibility by larval stage ................................... 28 Experiment 1b – black soldier fly susceptibility at pupal stage .................................... 29 Statistical Analysis ............................................................................................................................ 30 Experiment 2 –effect of larval injury on nematode infection ......................................... 30 Statistical Analysis ............................................................................................................................ 32 Experiment 3 – nematode production in black soldier fly .............................................. 32 Statistical Analysis ............................................................................................................................ 34 Results ................................................................................................................................... 36 Experiment 1a – black soldier fly susceptibility by larval stage ................................... 36 Experiment 1b – black soldier fly susceptibility at pupal stage .................................... 38 Experiment 2 – effect of larval injury on nematode infection ........................................ 40 Experiment 3 – nematode production ..................................................................................... 45 Discussion ............................................................................................................................