Michael Ani Nweze, Okoye Ikem Chris
Department of Zoology and Environmental Biology, University of Nigeria, Nsukka, Enugu State, Nigeria.
J Chem Ecol. 2025 Feb 1;51(1):17. doi: 10.1007/s10886-025-01558-6.
Forensic entomology has relied on species-specificity, quantitative and qualitative variations of cuticular hydrocarbons to successfully carry out chemotaxonomic identification of insects based on species, age and gender. This work studied the effects of dichlorvos on the cuticular hydrocarbon profiles of some adult sarco-saprophagous insects of forensic importance that fed on dichlorvos-poisoned carrions for utility during death investigations. Cuticular hydrocarbons (CHCs) were extracted from adult insects of the species Chrysomya albiceps, Sarcophaga exuberans, Musca domestica, Hermetia illucens, Dermestes maculatus and Necrobia rufipes from both dichlorvos-poisoned and control pig (Sus scrofa Linnaeus) carrions and subjected to chemotaxonomic profiling using Gas Chromatography-Mass Spectrometry (GC-MS). A total of 41 CHCs were successfully identified from insects of both the dichlorvos-poisoned and control carrions ranging from C8 to C33 carbons consisting of majorly the n-alkanes, methyl branched alkanes and an alkene. There was a higher abundance of CHCs present in the insects of dichlorvos-poisoned carrions than the control group. The highest mean peak concentration and abundance of the CHCs was recorded by 2,6,10,14 -Tetramethyl Pentadecane (10.38 ± 0.53 μg/mg for dichlorvos-poisoned carrions and 8.99 ± 1.13 μg/mg for the control carrions). The visualization of the species-specific differences in CHCs compositions showed less overlapping CHCs clusters and quantitative metrics of principal component analysis plots of the insects from both carrion groups with high eigenvalues > 3 which were indications of good species level discrimination. The study showed that insects' CHCs profiles of dichlorvos-poisoned and control carrions exhibited uniqueness cum variations in terms of abundance and chemical identity.
法医昆虫学依靠表皮碳氢化合物的物种特异性、定量和定性变化，成功地基于物种、年龄和性别对昆虫进行化学分类鉴定。这项工作研究了敌敌畏对一些具有法医重要性的成年食尸性昆虫表皮碳氢化合物谱的影响，这些昆虫以敌敌畏中毒的腐肉为食，用于死亡调查。从取食敌敌畏中毒猪（Sus scrofa Linnaeus）腐肉和对照猪腐肉的白纹伊蚊、丰盛肉蝇、家蝇、黑水虻、黄斑皮蠹和红胸郭公虫等成年昆虫中提取表皮碳氢化合物（CHCs），并使用气相色谱-质谱联用仪（GC-MS）进行化学分类分析。从取食敌敌畏中毒腐肉和对照腐肉的昆虫中成功鉴定出总共41种CHCs，碳链长度从C8到C33，主要包括正构烷烃、甲基支链烷烃和一种烯烃。取食敌敌畏中毒腐肉的昆虫中CHCs的丰度高于对照组。2,6,10,14-四甲基十五烷的CHCs平均峰浓度和丰度最高（敌敌畏中毒腐肉中为10.38±0.53μg/mg，对照腐肉中为8.99±1.13μg/mg）。CHCs组成的物种特异性差异可视化显示，两个腐肉组昆虫的CHCs簇重叠较少，主成分分析图的定量指标具有较高的特征值>3，这表明在物种水平上具有良好的区分度。研究表明，取食敌敌畏中毒腐肉和对照腐肉的昆虫的CHCs谱在丰度和化学特性方面表现出独特性和差异性。
