Template A v4.0 (beta): Created by L. Threet 01/2019 Roles and interaction of blow flies (Diptera: Calliphoridae) and introduced fire ants (Hymenoptera: Formicidae: Solenopsis invicta and S. invicta x richteri) in carrion decomposition in the southeastern United States By TITLE PAGE Grant Douglas De Jong Approved by: Jerome Goddard (Major Professor) Florencia Meyer (Co-Major Professor) Jeffrey W. Harris Natraj Krishnan Gerald T. Baker Kenneth Willeford (Graduate Coordinator) Scott T. Willard (Dean, College of Agriculture and Life Sciences) A Dissertation Submitted to the Faculty of Mississippi State University in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Life Sciences in the Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology Mississippi State, Mississippi November 2020 Copyright by COPYRIGHT PAGE Grant Douglas De Jong 2020 Name: Grant Douglas De Jong ABSTRACT Date of Degree: November 25, 2020 Institution: Mississippi State University Major Field: Life Sciences Major Professors: Jerome Goddard and Florencia Meyer Title of Study: Roles and interaction of blow flies (Diptera: Calliphoridae) and introduced fire ants (Hymenoptera: Formicidae: Solenopsis invicta and S. invicta x richteri) in carrion decomposition in the southeastern United States Pages in Study 276 Candidate for Degree of Doctor of Philosophy Invasive fire ants (Solenopsis invicta and its hybrid with S. richteri) have been reported from carrion in the southeastern United States and are considered a part of the succession community. Alteration of ecological processes by fire ants could affect forensic interpretation of entomological data; therefore, I conducted studies to investigate the relative roles and interactions of fire ants and blow flies in carrion decomposition. The blow fly species composition in Mississippi has not been studied since 16 species were reported in 1983. Specimens from the Mississippi Entomological Museum were used to update the checklist of the blow flies of Mississippi and produce a photographic key to adults and third instar larvae. A total of 23 species of blow flies are now known or expected to occur in the state. I conducted an experiment whereby portions of the succession fauna were excluded from access to carrion to study the relative effects of fire ants and blow flies on carrion decomposition and their interactions with each other. Fire ants made lesions in and partially buried carcasses, but their exclusion did not affect carrion decomposition rates; slightly affected the succession community; and strongly affected succession of blow flies, specifically. Lastly, I collected fire ants from mounds at set distances from carrion and analyzed their guts for pig and blow fly DNA. The probability of detecting pig or blow fly DNA in ants collected directly from carrion increased with each succeeding day, and the probability of detecting either pig or blow fly DNA in ant guts decreased with increasing distance between carrion and the mound. Probability of detecting pig or blow fly DNA in ant guts from ants collected directly from the carcasses was 42% and 33%, respectively. This study documented that fire ants scavenge on carrion, prey on other members of the succession fauna, and transfer acquired nutrients at least 3 m into the landscape. Thus, fire ants represent a barrier to normal faunal succession patterns on carrion and these delays should be considered by forensic entomologists for postmortem interval estimation. ACKNOWLEDGEMENTS I sincerely want to thank the following people for their role in helping me to do this Ph.D. research and produce this dissertation. Dr. Jerome Goddard and Dr. Florencia Meyer agreed to serve as my co-advisors despite my out-of-state residence, helped me plan and execute this project, and otherwise expertly shepherded me through the doctoral program and dissertation process. Dr. Jeff Harris, Dr. Natraj Krishnan, and Dr. Gerald Baker provided guidance as my other committee members and by providing comments on the proposal and draft dissertation. Kathy Breland, Kathy Beatty, and other administrative staff at the Mississippi State University (MSU) Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology helped keep me and my committee on track through the whole process. Dr. Jerome Goddard allowed use of his property in Mississippi as a field site. Likewise, Dr. Troy Shoemaker allowed use of Pensacola Christian College (PCC) recreational property, where Dr. Neil Waer and Mr. Paul LeFevers helped me identify locations on the property in which to do the research and assisted with other logistical concerns on site. Ms. Brooklyn Thompson, Ms. Catherine Gibson, Ms. Karson Pettit, Ms. Kristine Edwards, and Ms. Abby Peloquin assisted Dr. Jerome Goddard and Dr. Florencia Meyer with field sampling in Mississippi and/or conducted many of the preliminary polymerase chain reaction (PCR) optimization experiments on the pig and fly DNA in ant guts. Ms. Victoria Jefferson did her best to help me navigate the molecular biology lab. ii Dr. Richard Brown allowed, and Mr. Terry Schiefer facilitated, access to the Mississippi Entomological Museum for specimen study. This research received financial support from Dr. Jerome Goddard and Dr. Florencia Meyer. Mrs. Rosella Goddard deserves special acknowledgment since she helped with many behind-the-scenes logistical details like making all the mesh bags for the pigs and coordinating conference calls. The following taxonomic experts provided identifications or graciously verified or corrected my identifications: Dr. Paula Cushing, Denver (Colorado) Museum of Nature and Science (DMNS) (Aranea); Dr. Frank- Thorsten Krell, DMNS (Coleoptera: Scarabaeoidea); Mr. Joe MacGown, MSU (Hymenoptera: Formicidae); Mr. Terry Schiefer, MSU (Coleoptera: Cicindelidae); Dr. Aresia Watson, PCC, Mr. Caleb Bomske, Kansas State University, and Mr. Josh Poulin, PCC (plants). The PCC Abeka Fund, chartered by Dr. Arlin Horton and administered by Dr. Raylene Cochran, funded my tuition and many expenses. Dr. Shane Smith and Dr. Aresia Watson arranged my teaching schedule and other responsibilities at PCC to accommodate these studies (and threw in the occasional curveball like adding brand new courses to be developed and professional videotaping of some of my courses for online students). Mr. Timothy Jones, Miss Sarah Nelson, Mr. Kevin Quito, and Miss Cynthia Autry were kind enough to step in when schedule conflicts could not be avoided. Special acknowledgment goes to the global COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which drastically altered life as we knew it at MSU and at PCC for all of 2020. The day-by-day government updates and policy changes and both colleges’ transition to fully online learning for the spring 2020 semester and modified schedules in the fall 2020 semester reinforced the words of the apostle James, the brother of Jesus Christ, who said, “ Go to now, ye that say, To day or to morrow we will go into such a city, iii and continue there a year, and buy and sell, and get gain: Whereas ye know not what shall be on the morrow. For what is your life? It is even a vapour, that appeareth for a little time, and then vanisheth away. For that ye ought to say, If the Lord will, we shall live, and do this, or that” (Authorized King James Version, James 4: 13-15). I especially thank my wife, Nikki, for allowing time for me to pursue my longtime dream of obtaining my doctoral degree, encouraging and cheerleading this endeavor. She and my two daughters, Abby and Katie, put up with piglets and DNA samples in the deep freezer (and sometimes the back yard). They also often faced long days and evenings in which I was locked in my office identifying insects in samples or writing and weeks when I travelled to MSU from Pensacola for classes and research. Hopefully, despite a few missed engagements, they realize that I love them and that I tried to make as much quality time as possible for them. ILYMoTTS, Honey! iv TABLE OF CONTENTS ACKNOWLEDGEMENTS ............................................................................................................ ii LIST OF TABLES ......................................................................................................................... ix LIST OF FIGURES ....................................................................................................................... xi LIST OF SYMBOLS AND ABBREVIATIONS ........................................................................ xvi CHAPTER I. BACKGROUND AND LITERATURE REVIEW ON CARRION ECOLOGY WITH SPECIAL EMPHASIS ON THE SOUTHEASTERN UNITED STATES ................................................................................................................1 Carrion as a Medium for Research ....................................................................................1 Carrion Decomposition and Succession Studies in the Southeastern United States ......................................................................................................................5 The Process of Carrion Decomposition ...........................................................................13 The Carrion Succession Community ...............................................................................16 Blow fly Community of Mississippi and the Florida Panhandle ..............................16 Ant Relations with Carrion ........................................................................................18