Open P Hunt ENT MS Thesis.Pdf

The Pennsylvania State University The Graduate School Entomology EFFECT OF WEATHER VARIABLES ON DECOMPOSITION AND TIME OF DEATH ESTIMATION IN TWO HABITATS IN CENTRAL PENNSYLVANIA A Thesis in Entomology by Patricia L. Hunt 2010 Patricia L. Hunt Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science August 2010 The thesis of Patricia L. Hunt was reviewed and approved* by the following: Ke Chung Kim Professor of Entomology Thesis Advisor Dennis Calvin Professor of Entomology James Marden Professor of Biology Gary Felton Professor of Entomology Head of the Department of Entomology *Signatures are on file in the Graduate School iii ABSTRACT The goal of this thesis was to look at the application of forensic entomology in Central Pennsylvania by looking at the meteorological factors involved in post-mortem interval estimation (PMI) during both the summer and winter months. Additionally, the applicability of site-specific weather modeling was explored to see how accuracy in PMI estimation can be improved by technology. It was found that site-specific weather modeling does improve the accuracy of PMI estimations over temperatures recorded at the nearest government weather station. Along with this finding, it became evident that ambient temperature is not the only consideration in insect development associated with decomposition. Soil and maggot mass temperature are also important factors in obtaining greater accuracy in PMI estimations as well as wintertime survival of larvae. During the winter months, it was found that there are differences in decomposition pattern and insect colonization patterns when comparing both wintertime environment (open field vs. deciduous forest) and time of year (winter vs. summer). iv TABLE OF CONTENTS LIST OF FIGURES ................................................................................................................. vi LIST OF TABLES ................................................................................................................... ix ACKNOWLEDGEMENTS ..................................................................................................... x Chapter 1 Introduction ............................................................................................................ 1 Chapter 2 Literature Review: Microclimatology in Forensic Entomology ............................ 4 Chapter 3 Materials and Methods ........................................................................................... 8 3.1 Materials and Field Study Design .............................................................................. 8 3.2 Study Sites.................................................................................................................. 11 Chapter 4 Exploratory Experiment on Meteorological Factors Associated with Environmental Locations ................................................................................................. 15 4.1 Ambient Temperature ................................................................................................ 15 4.2 Maggot Mass Temperature ........................................................................................ 20 4.3 Soil/Ground Temperature........................................................................................... 20 4.4 Base Model and Data Analysis: Site-Specific Weather Modeling ............................. 21 4.4.1 Data Analysis .................................................................................................. 22 4.5 Conclusion ................................................................................................................. 25 Chapter 5 Effects of Weather Variables on Decomposition and Insect Development ........... 27 5.1 Impacts of Temperature ............................................................................................. 28 5.2 Impacts of Light ......................................................................................................... 31 5.3 Soil Temperature and Moisture Dynamics ................................................................ 35 5.4 Conclusion ................................................................................................................. 37 Chapter 6 Comparative Ecology of Arthropod Diversity and Decomposition between Open Grassland and Woodland ........................................................................................ 39 6.1 Materials and Methods ............................................................................................... 40 6.1.1 Experimental Layout ....................................................................................... 40 6.1.2 Experimental Design ....................................................................................... 40 6.1.3 Insect Collect and Decomposition Observations ............................................. 41 6.1.4 Weather Data Collection Methods .................................................................. 42 6.2 Decomposition Observations at Each Experimental Site ........................................... 45 6.3 Colonization Timing, Population Stage Structure, Species Composition and Biodiversity .............................................................................................................. 48 6.3.1 Stage Structure ................................................................................................ 48 v 6.3.2 Species Composition and Biodiversity............................................................ 50 6.4 Relationships Between Temperatures In and Around the Decaying Carcass, Insect Life Stage, and Time After Death .................................................................. 52 6.4.1 Ground and Maggot Mass Temperature Related to Decomposition Stage and Insect Population ....................................................................................... 52 6.4.2 Ambient Air Temperature Related to Decomposition Stage and Insect Population ......................................................................................................... 58 6.5 Conclusion ................................................................................................................. 60 Chapter 7 Meteorological Factors Influencing Winter Larval Survival ................................. 62 7.1.Methods and Materials ............................................................................................... 63 7.1.1 Experimental Sites ........................................................................................... 63 7.1.2 Experimental Materials and Methodology ...................................................... 65 7.3 Results and Discussion ............................................................................................... 67 Chapter 8 Summary and Conclusion ...................................................................................... 81 Literature Cited ........................................................................................................................ 83 Appendix General Methodology for Determining PMI .......................................................... 91 A.1 Development Equation and Degree Hour Derivation ............................................... 91 A.2 Estimating the Window of Uncertainty ..................................................................... 95 vi LIST OF FIGURES Figure 2-1: Graphical representation of ASOS station locations for the United States (Courtesy of NOAA) ........................................................................................................ 6 Figure 3-1: Example of field set-up for experiments. .............................................................. 9 Figure 3-2: Diagram of logger set-up around the carcasses. ................................................... 10 Figure 3-3: Map of the Penn State campus and surrounding area. Red dot represents Location 1 while the yellow dot represents Location 2. The green box represents the Walker Building, and the blue box represents the location of the University Park Airport (KUNV). (map from campusmaps.psu.edu)........................................................ 12 Figure 3-4: On the right, a photograph of the location taken on May 23, 2005. On the left, a close-up map of the Lot 18 location. The locations of carcasses 1.1 (A), 1.2(B), and 1.3 (C) are also indicated (map from campusmaps.psu.edu). ....................... 13 Figure 3-5: On the left, a close-up map of the Penn State Living Filter indicating the relative position of carcasses 2.1 (D) and 2.2 (E). On the right, a photograph of the location taken May 23, 2005. Carcass 2.is location on the right side of the pipe, while carcass 2.2 is to the left (map from campusmaps.psu.edu). ................................... 14 Figure 4-1: Time series of ambient temperature from May 30, 2005 through June 7, 2005 at the exposed experimental site (Site 1.3), a semi-shaded site (Site 1.2), and a shaded site (Site 2.1). ....................................................................................................... 17 Figure 4-2: Time series of average hourly ambient temperature from May 30, 2005 through June 7, 2005 at the exposed site (Site 1.3), shaded site (Site 2.1), and the control site of KUNV. ...................................................................................................... 18 Figure 4-3: Comparison of the ambient temperatures at the control sites and the exposed site (above) and the

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