Forensic entomotoxicological appraisal of carrion insects found on pigs poisoned with Gammalin-20 was carried out at the back of the stadium on the campus of the University of Ibadan. A total of three 3-month old domestic pigs, Sus scrofa L., weighing between 10.5 and 11.3 kg were used as surrogate human models. Two pigs were euthanized with Gammalin-20 by administering 180 ml and 200 ml separately, while the third one was sacrificed without any poison and served as the control experiment. After death was confirmed, each pig was immediately mounted on sawdust and setup at about 50 m apart to allow for arthropod colonization without cross migration, thereby representing three different replicates of the same study.
The pigs were left to decompose, and it was discovered that there were five phases of decomposition namely: fresh, bloated, active, advanced and dry decay stages. The decomposition process of the carrions took twenty days in the control experiment and thirty-four days in those treated with Gammalin-20. Four families of flies were found (Calliphoridae, Sarcophagidae, Muscidae and Dermestidae) and seven species (Chrysomya abiceps, Chrysomya regalis, Sarcophaga spp, Phormia regina, Lucilia sericata, Dermestes maculatus and Musca domestica). Their activities on the carrions included consumption of the carrion tissues and using same to propagate their progeny. Calliphoridae was observed to be the most dominant family in nearly all the stages of decomposition with 108 individuals, followed by the Sarcophagidae with 98 individuals, the Muscidae with 85 individuals and the Dermestidae with 10 individuals. Flies found on the carrions were collected with a sweep net and preserved in 70% ethanol for identification. The succession pattern of the flies, their abundance, rate of development, effects of the poison on the developmental pattern were all determined.
Warning: Contains images of dead and decomposing animals (pp. 41-45).
Table of Contents
CHAPTER ONE
1.0 Introduction
1.1 Forensic entomotoxicology
1.2 Necrophagous Species
1.3 Gamalin-20
1.4 Aims and Objectives of the Study
CHAPTER TWO: LITERATURE REVIEW
2.1. Forensic entomology
2.2. Areas of forensic entomology
2.3. Decomposition
2.4. Carrion Insect Succession
2.5. Factors Influencing Carrion Insects Development
2.6. Arthopods Associated With Carrion
2.7. Forensic Entomotoxicology
2.8. Justification of the study
CHAPTER THREE
3.1. Study Site
3.2. Sample collection and processing
3.3. Sample analyses
CHAPTER FOUR: RESULTS AND DISCUSSION
4.1. Abundance and species composition of carrion insects on pig carcass
4.2. Carrion Insect Succession on Pig Carcass
4.3. Effect of Gammalin 20 the length of larva and weight of larva
Research Objectives and Core Themes
The primary aim of this research is to evaluate the forensic entomotoxicological impact of the pesticide Gammalin-20 on carrion insects found on domestic pig carcasses, using these data to estimate the post-mortem interval and understand decay patterns in a controlled environment.
- Analysis of carrion insect abundance and species composition under toxic influence.
- Examination of insect ecological succession patterns during decomposition.
- Assessment of how Gammalin-20 concentrations affect larval developmental rates.
- Comparison of decomposed carcass data between poisoned subjects and a control group.
Excerpt from the Book
1.1 Forensic entomotoxicology
Entomotoxicology is a relatively new branch of forensic entomology. It studies the application of toxicological analysis to carrion feeding insects in identifying toxins and drugs present on intoxicated tissues. Entomotoxicology also investigates the effects of such substances on arthropod development.
Forensic entomotoxicology includes the study of the effects of drugs on the development rate of carrion-feeding insects and the use of these as alternative sample in the absence of other tissues. (Kapil and Paul ,2013) Most forensic entomotoxicological studies have concentrated on commonly prescribed drugs such as. Insect specimens collected from decomposing bodies enable forensic entomologists to estimate the minimum post-mortem interval (PMI). The most common application of entomological evidence in forensic medicine is the estimation of the time of death, i.e., of the decomposing interval. There are additional applications which include determination of the place of death, cause of death or detection of an ante mortem trauma.
Summary of Chapters
CHAPTER ONE: Provides an introduction to forensic entomology and the specific discipline of forensic entomotoxicology, including the study of Gammalin-20.
CHAPTER TWO: LITERATURE REVIEW: Analyzes the scientific foundations of decomposition stages, insect succession, and the various factors that influence the development of necrophagous insects.
CHAPTER THREE: Details the methodologies used for the study, including the study site selection, sample collection (insects and maggots), and the environmental variables monitored.
CHAPTER FOUR: RESULTS AND DISCUSSION: Presents the findings regarding species abundance, succession matrices, and the observed effects of Gammalin-20 concentrations on the physical properties of larvae.
Keywords
Forensic entomology, entomotoxicology, Gammalin-20, decomposition, carrion insects, pig carcass, post-mortem interval, PMI, larval development, necrophagous species, Diptera, Coleoptera, insect succession, environmental variables, toxicology.
Frequently Asked Questions
What is the primary scope of this research?
The research investigates the influence of the pesticide Gammalin-20 on the colonization and development of insects on decomposing pig carcasses to assist in forensic post-mortem interval estimation.
What are the central themes of the study?
The core subjects include forensic entomology, the ecological process of decomposition, the toxicological impact on arthropod development, and comparative analysis of insect succession.
What is the ultimate goal of the investigation?
The goal is to determine how chemical substances like Gammalin-20 alter natural decay rates and insect developmental timelines, allowing for more accurate forensic conclusions in potential suicide cases.
Which scientific methods were applied in this work?
The methodology involved comparative field experiments using domestic pigs, sweep net insect sampling, microscopic identification of larvae, and biometric measurement of larval length and weight.
What does the main body of the work cover?
The work covers a thorough literature review, detailed field procedures carried out at the University of Ibadan, and a comprehensive analysis of the resulting data on species composition and succession.
Which keywords define this study?
Key terms include Forensic entomology, Forensic entomotoxicology, Gammalin-20, Post-mortem interval (PMI), Carcass decomposition, and Arthropod succession.
How does Gammalin-20 generally affect insect colonization?
The study concludes that Gammalin-20 acts as a significant deterrent, delaying initial insect colonization and actively slowing down the rate of larval development compared to non-poisoned subjects.
What is the significance of using pigs as human models?
Domestic pigs (Sus scrofa L.) are widely accepted surrogate models in forensic entomology due to their similar size, skin characteristics, and decomposition profile in comparison to human bodies.
- Quote paper
- Emmanuel Tyokumbur (Author), 2023, Responses of Carrion Insects to Gammalin - 20 Poisoning. A Forensics Crime Evaluation Using Euthanized Pigs, Munich, GRIN Verlag, https://www.hausarbeiten.de/document/1360353
