Forensic Entomology and Insect Succession

Forensic Entomology

• Identifying time and place of death is the primary use in post-mortem intervals for homicide victims
• Also used for illegal drugs, food poisoning, identifying other materials
• Insects are used to gain information about the timeline after death, including the location of colonization
• The timeline: death, stages of putrefaction, stages of mummification, colonization, growth of larvae, pupae, adults emerge
• Forensic entomology uses insects to identify the time of death and the location of an event
• The theoretical model of insect succession on a corpse is used to infer the information
• These changes indicate the age of maggots, which is used to determine the time of death

Insect Succession Variability

• Intrinsic factors, such as early, optimal, and late colonizers, the distance to nearest corpse, the number of colonizers available, and intraspecific competition, play a role in insect succession
• Extrinsic factors such as, moisture, presence of sun vs shade, the species present, the distance to nearest corpse, the commonness or rarity of other corpses, predators, parasites, and diseases also influence succession
• Variability associated with the carcass such as size of the corpse, presence of drugs, food, health of the individual, amount of fat vs lean meat, order of organs colonized, order of utilization, exposure of interior organs and body cavity, and access to the carcass, all contribute to insect succession

Fly Anatomy and Identification

• The identification key helps determine species by leading you through a series of questions about anatomical features of an insect
• Use the key, and follow the steps to identify the specific genus or species
• The first step is to analyze the general shape of the insect

Blowflies

• Blowflies are forensically useful for determining PMI (Post Mortem Interval), as they are attracted to carrion
• Blowfly species are often used to estimate the PMI
• Specific species thrive in different habitats and climates, impacting the timing and duration of insect succession

Taxonomic Identification Key

• It is important to follow the key step-by-step, and review each step carefully
• Note down your observations and decisions so that research can be verified and corrected if mistakes are made
• If you encounter an insect that does not fit the key, it is important to note the reason for the disagreement and seek further identification
• The identification key guides you through a series of questions regarding the insect's morphology to help you identify the species

Forensic Entomology Research

• Research projects in forensic entomology can involve various areas of study such as blowfly attraction to different carrion, observer influence on blowfly behavior, burying beetles and trap height, trap design, urban and rural habitats, surveys of forensic insects found near carrion, and more.

Research Project Design

• Students are expected to design and conduct their own research projects, including:
  • The relevance of the project
  • Appropriate methods
  • Experimental design
• Students need to choose a topic that is relevant to forensic entomology and obtain approval from the instructor.
• Students are responsible for supplying and constructing any traps or equipment needed for their projects.

Research Project Outline

• The introduction should include:
  • The research topic
  • The scientific background
  • A review of relevant literature
  • The theory behind the research project
• Materials and methods should include:
  • Descriptions of the animals collected
  • Collection methods
  • Data analysis and statistical methods used
• The Results section should present the findings of the research in a comprehensive and clear manner, including figures and tables to support the findings.
• The Discussion section should:
  • Discuss key findings and their significance in relation to other research and current knowledge.
  • Discuss the project limitations and suggest future research avenues related to the findings.
• All references used in the report should be cited in the text and listed in a separate section.