The Pennsylvania State University The Graduate School Department of Entomology MUSHROOM FLIES AND FARM WORKERS: FLY ECOLOGY AND VECTOR COMPETENCY AND IPM IMPLEMENTATION AMONG HIPSANIC MUSHROOM FARMWORKERS. A Dissertation in Entomology and International Agricultural and Development by Maria Mazin 2018 Maria Mazin Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy December 2018 ii The dissertation of Maria Mazin was reviewed and approved* by the following: Edwin G. Rajotte Professor of Entomology Dissertation Advisor Chair of Committee Nina E. Jenkins Professor of Entomology Thomas C. Baker Distinguished Professor of Entomology John Pecchia Professor of Mushroom Science and Technology Melanie Miller Foster Special Member Assistant Teaching Professor of International Agriculture Gary Felton Professor of Entomology Head of the Department of Department or Graduate Program *Signatures are on file in the Graduate School iii ABSTRACT The mushroom sciarid fly, Lycoriella ingenua and the mushroom phorid fly Megaselia halterata are important pests in commercial mushroom farming in the U.S. The Mushroom Sciarid fly has been anecdotally associated with the occurrence of the fungal pathogen Trichoderma aggressivum ft. aggressivum in commercial mushroom farms. It has been reported that female L. ingenua are attracted to this fungus in mushroom compost for oviposition. The research presented in this dissertation shows that L .ingenua benefits from its attraction to the fungus and provides experimental evidence for the mushroom sciarid flys’ acquisition and mechanical vectoring of T.aggressivum spores, proving that the association between organisms is mutual. The ecology and behavior of the mushroom phorid fly outside mushroom farms in the U.S. has not been studied. This dissertation presents data on the flight activity, distribution and behavioral aspects of M. halterata in and around commercial mushroom farms in Chester County, PA. Specifically, flight activity and mating behavior in relation to the time of day. Results have implications for fly management such as timing of farm activity to improve fly exclusion and the use of mating disruption techniques. M. halterata population dynamics within commercial mushroom crops is characterized and factors related to fly density is analyzed and discussed. Mushroom Integrated Pest Management is crucial to the success of mushroom farming in PA. The success of IPM depends on the extent to which it is implemented by farm owners and farmworkers alike. A study where the effect of mushroom farmworkers perceptions around mushroom pests and diseases on farmworker IPM behaviors is presented. Results show that high risk and control perceptions around mushroom pests and pathogens rather than knowledge on IPM predicts whether farmworkers will engage in IPM behaviors on the job. These results have applications for the development of IPM intervention programs among mushroom farmworkers. iv TABLE OF CONTENTS LIST OF FIGURES ........................................................................................................................ ix LIST OF TABLES .......................................................................................................................... xi ACKNOWLEDGEMENTS ........................................................................................................... xii Chapter 1 Introduction .................................................................................................................... 1 Flies as pests in modern mushroom production ....................................................................... 1 IPM implementation for Hispanic component of the mushroom industry ............................... 4 Overview of chapters ............................................................................................................... 6 Literature review ...................................................................................................................... 8 Commercial mushroom farming ............................................................................................ 8 The mushroom farming process and mushroom integrated pest management efforts .......... 9 The mushroom sciarid fly Lycoriella ingenua ..................................................................... 13 The mushroom phorid fly Megaselia halterata ................................................................... 16 Mushroom flies and green mold disease ............................................................................. 21 Hispanic farmworkers and the Health Belief Model ........................................................... 24 Chapter 2 The mushroom sciarid fly, Lycoriella ingenua, benefits from its association with green mold disease (Trichoderma aggressivum) in commercial mushroom production ......................... 28 Abstract .................................................................................................................................. 28 Introduction ............................................................................................................................ 29 Materials and methods ........................................................................................................... 30 Fly rearing............................................................................................................................ 30 v Substrates ............................................................................................................................. 31 Experimental design ............................................................................................................ 33 Statistical analysis ................................................................................................................ 34 Results .................................................................................................................................... 35 Emergence ........................................................................................................................... 35 Development ........................................................................................................................ 36 Female wing length ............................................................................................................. 38 Female body length ............................................................................................................. 40 Discussion .............................................................................................................................. 40 Conclusions ............................................................................................................................ 44 Chapter 3 Mushroom Sciarid Fly, Lycoriella ingenua (Diptera: Sciaridae) adults and larvae vector Mushroom Green Mold (Trichoderma aggressivum ft. aggressivum) spores. .............................. 45 Abstract .................................................................................................................................. 45 Introduction ............................................................................................................................ 46 Materials and methods ........................................................................................................... 49 Sciarid flies .......................................................................................................................... 49 Trichoderma aggressivum cultures ...................................................................................... 49 Distribution of T. aggressivum spores on adult flies with scanning electron microscopy .. 50 Adult spore vectoring .......................................................................................................... 50 Larval vectoring experiment ................................................................................................ 52 Molecular Pathogen Confirmation ...................................................................................... 53 vi Statistical analysis ................................................................................................................ 54 Results .................................................................................................................................... 55 Detection of T. aggressivum spores on adult flies with scanning electron microscopy ...... 55 Adult vectoring study .......................................................................................................... 56 Larval consumption and excretion of T. aggressivum spores .............................................. 58 Molecular Pathogen Confirmation ...................................................................................... 59 Discussion .............................................................................................................................. 60 Conclusions ............................................................................................................................ 63 Chapter 4 Activity and Distribution of the Mushroom Phorid Fly, Megaselia halterata, In and Around Commercial Mushroom Farms ......................................................................................... 64 Abstract .................................................................................................................................