A study was carried out on the forensic entomological evaluation of carrion insects of pigs poisoned with paraquat between July and September 2018, on the main campus of the University of Ibadan. Paraquat is a commonly used suicide agent because it is easily available and very cheap. Pigs for the study were obtained from Akinyele meat market in Ibadan, Oyo state. The pigs were then weighed and euthanized with 60ml and 80ml of paraquat while the third pig without poison served as the control. Adult carrion insects were collected from the carrions using a sweep net and they are then immobilized using by spraying them with insecticide. The larva were collected into a bowl by using a spoon. The larvae were then immobilized with hot water and are later placed in appropriate sample bottles. Pupae were collected using a forces.
Table of Contents
CHAPTER ONE
INTRODUCTION
1.1 Entomotoxicology
1.2 Carrion insects
1.3 Paraquat
1.4 Aims and Objectives of the Study
CHAPTER TWO
LITERATURE REVIEW
2. 0 Introduction
2.1 Medico-legal forensic entomology
2.2 Stored product entomology
2.3 Urban forensic entomology
2.4 Decomposition
2.5 Insect Succession
2.6 Factors affecting fly development
2.7 Types of Carrion Insect and Arthropods
2.8 Paraquat
2.9 Review of Previous Literatures
CHAPTER THREE
MATERIALS AND METHOD
3.1 Study Site
3.2.1 Sample collection and processing
3.2.2 Preparation of Pigs for Set-up
3.2.3 Mounting the pigs
3.2.4 Sampling of carrion insect stages
3.3 Measurement of larval body length and weight
3.4 Measurement of carcass temperature and humidity
CHAPTER FOUR
RESULTS
4.1 Abundance and species composition of carrion insects on pig carcass
4.2 Carrion insect succession on pig carcass
4.3 Effects of paraquat on the length and weight of the control, 60ml and 80ml larva
4. 4 Variations in environmental variables at the field site
CHAPTER FIVE
DISCUSSION
5.1 Abundance and species composition of carrion insects on pig carcass
5.2 Carrion insect succession on pig carcass
5.3 Effects of paraquat on the length and weight of larvae
5.4 Variations in environmental variables at the field site
5.5. Conclusion
Research Objectives & Core Themes
This study aims to perform a forensic entomotoxicological evaluation of carrion insects associated with pig carcasses treated with varying doses of paraquat. The research investigates how Paraquat poisoning influences the successional patterns, abundance, and species composition of insects on decomposing remains, while also assessing its impact on larval development, specifically regarding length and weight, compared to untreated control groups.
- Entomotoxicological analysis of Paraquat-poisoned remains.
- Succession patterns of carrion insects during decomposition.
- Effects of toxic substances on larval growth rates.
- Environmental influences (temperature/humidity) on insect colonization.
- Forensic implications for determining Post Mortem Interval (PMI).
Excerpt from the Book
1.1 ENTOMOTOXICOLOGY
Entomotoxicology is derived from "entomo" which literally means insects and "toxicology" which means the study of toxins, therefore Entomotoxicology can simply be defined as the study of toxins or poisons in insects (Amendt et al, 2004). There has been increase in drug related deaths in many parts of the world both in developing countries like Nigeria and developed countries like USA(Catts and Goff, 1992). Sometimes these corpses remain undiscovered for many days or weeks after death. Most times, the corpses are in the skeletonized stage of decomposition or most other stages of decomposition in which there won't be enough tissue on the corpse that can allow for post mortem evaluation (Goff, 1993). But scientist and law enforcement agencies must find one way or another to investigate the cause of the death and the type of poison so that they can know if the death is as a result of homicide, suicide, or if the death occurred as a result of drug overdose(Catts and Goff 1992).
Forensic entomotoxicology is the method of combating crimes using the knowledge from the study of toxins or poisons in insects (Catts and Goff, 1992). It can also be defined as the application of the study of poisons present in insects in unravelling possible crimes. In recent times, it has been proven that it is possible to detect various toxins and controlled substances by analysis of insects, larvae skins or puparial skin present near the corpse. (Crosby et al, 1986). Forensics entomotoxicology is also important in contraband trafficking (Crosby et al, 1986). In many part of the world, the sale of cocaine and some other narcotics have been generally banned. If a forensic Entomotoxicological study is conducted on a body and the trace of cocaine or other narcotics is found on the insect, it is then obvious that the decedent must have been taking such narcotics while he or she was alive. Forensic entomotoxicology is also very useful in civil cases involving the
Summary of Chapters
CHAPTER ONE: Provides an introduction to the discipline of entomotoxicology and defines the scope, importance, and specific research objectives concerning Paraquat-poisoned carrion.
CHAPTER TWO: Reviews existing literature on forensic entomology, including the various fields of study, stages of decomposition, factors influencing insect colonization, and the toxicological effects of Paraquat.
CHAPTER THREE: Outlines the materials and methods used in the study, including the study site, preparation of pigs, infestation and processing of carrion samples, and the measurement techniques for larval growth and environmental variables.
CHAPTER FOUR: Presents the results of the abundance, species composition, and insect succession observed on the pig carcasses, alongside the comparative data on the effects of Paraquat on larval development.
CHAPTER FIVE: Discusses the findings, interpreting the data in the context of forensic entomotoxicology and environmental variables, and concludes on the impact of drugs on carrion insect diversity and abundance.
Keywords
Forensics, Forensic entomology, Toxicology, Paraquat, Insect carrion, Decomposition, Crime, Muscidae, Calliphoridae, Sarcophagidae, PMI, Post Mortem Interval, Larval development, Successional patterns, Entomotoxicology
Frequently Asked Questions
What is the core focus of this research?
The research focuses on forensic entomotoxicology, specifically analyzing how the presence of the herbicide Paraquat in pig carcasses affects the colonization and development of carrion-visiting insects.
What are the primary fields of study included in the work?
The study incorporates elements of forensic entomology, toxicology, insect ecology, and decomposition studies to evaluate the influence of chemical substances on necrophagous fauna.
What is the main objective of this study?
The primary goal is to assess how Paraquat poisoning alters the abundance, species composition, and successional patterns of insects on carcasses, and whether these changes correlate with dosage levels.
Which scientific methodology is applied?
Field experiments involving controlled pig carcasses (control, 60ml, and 80ml Paraquat groups) were conducted, followed by systematic collection, observation, and statistical analysis of insect samples and larval growth parameters.
What does the main body cover?
The main sections cover extensive background literature on insects and toxicology, detailed experimental setup and sampling protocols, data on insect species abundance/succession, and analysis of larval growth variations.
Which characteristic keywords define this study?
Key terms include Forensics, Forensic entomology, Toxicology, Paraquat, Insect carrion, Decomposition, Crime, and larval development parameters.
How does Paraquat specifically affect larval length and weight?
The results indicate that Paraquat exposure leads to retarded growth, with treated larvae showing a reduced mean length and weight compared to larvae from the untreated control group.
Does the dosage of Paraquat change the outcome?
Yes, the study establishes that as the concentration of Paraquat dosage increases, there is a corresponding reduction in the overall composition, abundance, and diversity of carrion insects.
Is there a difference in species richness between control and poisoned groups?
Yes, the control group exhibited higher species diversity and abundance compared to the Paraquat-poisoned groups, demonstrating that poisoning creates a less favorable environment for certain insect species.
Why are pigs used as models in this forensic research?
Pigs are utilized because their physical characteristics, such as fat distribution, hair cover, and decomposition patterns, closely resemble those of human bodies, making them excellent models for forensic inferences.
- Quote paper
- Emmanuel Tyokumbur (Author), 2020, Paraquat Effects on Carrion Insects. A Forensics Entomotoxicological Assessment Using Euthanized Pigs, Munich, GRIN Verlag, https://www.hausarbeiten.de/document/1360162
