Advances and Current Status in the Use of Cuticular Hydrocarbons for Forensic Entomology Applications

Cuticular hydrocarbons (CHCs) are long-chain lipids found on the exoskeletons of insects, serving primarily as a protective barrier against water loss and environmental factors. In the last few decades, the qualitative and quantitative analysis of CHCs, particularly in blow flies, has emerged as a valuable tool in forensic entomology, offering promising potential for species identification and age estimation of forensically important insects. This review examines the current application of CHC analysis in forensic investigations and highlights the significant advancements in the field over the past few years. Studies have demonstrated that CHC profiles vary with insect development, and while intra-species variability exists due to factors such as age, sex, geographical location, and environmental conditions, these variations can be harnessed to refine post-mortem interval (PMI) estimations and improve the accuracy of forensic entomological evidence. Notably, CHC analysis can also aid in distinguishing between multiple generations of insects on a body, providing insights into post-mortem body movement and aiding in the interpretation of PMI in complex cases. Furthermore, recent studies have investigated the variability and degradation of CHCs over time, revealing how environmental factors-such as temperature, humidity, UV light exposure, and toxicological substances-affect CHC composition, providing valuable insights for forensic investigations. Despite the promise of CHC profiling, several challenges remain, and this review also aims to highlight future research directions to enhance the reliability of this technique in forensic casework.