Thesis
Cuticular hydrocarbon analysis for the identification and ageing of Lucilia sericata (Meigen) (Diptera: Calliphoridae) spiked with glyphosate
Honours, Murdoch University
2024
Abstract
In a suspicious death investigation where blowfly puparia are collected from the scene, cuticular hydrocarbon (CHC) analysis may provide valuable information in the estimation of the post-mortem interval (PMI). An understanding of the factors that influence CHC composition is useful to facilitate species identification and ageing, which is critical for application in casework. Glyphosate is the active ingredient of a widely used herbicide that has been implicated in poison-related deaths worldwide. The aim of this study was to investigate whether a glyphosate-based herbicide affected the CHC profile of full and empty puparia of the common greenbottle blowfly Lucilia sericata (Meigen). Colonies of L. sericata were reared under controlled laboratory conditions (24 ± 1°C, 60% humidity), and fed either glyphosate-spiked chicken liver (LD50 of 5,037 mg/kg) or untreated chicken liver (control). Samples of full puparia (1-, 5-, and 9-d post pupation) and empty puparia were collected and analysed using gas chromatography-mass spectrometry (GC-MS) to obtain the CHC profile. Principal component analysis (PCA) was then applied to visualise distinctions. For both full and empty puparia (spiked and control), CHCs identified ranged between C21-C33. Results showed that glyphosate had a significant effect on all full pupal stages, allowing for treated to be differentiated from untreated using PCA and preventing ageing in the spiked group, while presenting no significant effect on the CHC profile of empty puparia. As the effect was found to be more quantitative than qualitative, this study reveals the potential for CHC analysis as a complementary tool for species identification in poison cases. Overall, this study further underlines the potential of the use of CHC analysis in forensic entomology, extending its application to poison cases and entomotoxicology.
Details
- Title
- Cuticular hydrocarbon analysis for the identification and ageing of Lucilia sericata (Meigen) (Diptera: Calliphoridae) spiked with glyphosate
- Authors/Creators
- Bobby J Stewart-Yates
- Contributors
- Paola A. Magni OSI (Supervisor) - Murdoch University, School of Medical, Molecular and Forensic SciencesGarth Maker (Supervisor) - Murdoch University, Centre for Computational and Systems Medicine
- Awarding Institution
- Murdoch University; Honours
- Identifiers
- 991005687470207891
- Murdoch Affiliation
- School of Medical, Molecular and Forensic Sciences
- Resource Type
- Thesis
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