Postmortem Attraction of Sarcosaprophagous Diptera to Tramadol-Treated Rats and Morphometric Aspects of the Developed Larvae

A review of multi-disciplinary decomposition research and key drivers of variation in decay

The decomposition of animal remains is a multifaceted process, involving ecological, biological, and chemical interactions. While the complexity is acknowledged through concepts like the necrobiome, it's unclear if this complexity is reflected in research. Appreciation of the complexity of decomposition is crucial for identifying sources of variation in estimations of time since death in medico-legal science, as well as building broader ecological knowledge of the decomposition process. To gain insights into the extent of multidisciplinary research in the field of decomposition science, we conducted an examination of peer-reviewed literature on four key drivers of variation: volatile organic compounds, microbes, drugs/toxins, and insects. Among 650 articles, we identified their scientific discipline, driver/s of variation investigated, and year of publication. We found that 19% explored relationships between two drivers, while only 4% investigated interactions between three. None considered all four drivers. Over the past three decades, there has been a steady increase in decomposition research publications, signifying its growing importance. Most research (79%) was linked to forensic science, highlighting opportunities for interdisciplinary collaboration in decomposition science. Overall, our review underscores the need to incorporate multidisciplinary approaches and theory into contemporary decomposition research.

Unusual concentration of tramadol detected in cadaver in the last stage of decomposition and in fly larvae in the immediate vicinity: case report and literature review

Determination of the manner and cause of death from skeletal remains is almost always very difficult and can be a challenge for medical examiners. At the end also on skeletal remains, it is possible to assess mechanical, chemical, and thermal injuries, although it can be usually impossible. Possibilities to analyze biological material for the presence of drugs are also limited. The present study describes a case of a homeless man's skeletal remains on which a large number of fly larvae were found. Unusually high concentration of tramadol (TML) in the bone marrow (BM) = 4530 ng/g, muscle (M) = 4020 ng/g, and fly larvae (FL) = 280 ng/g was detected using a validated GC/MS method. In all analyzed samples, caffeine and N-desmethyltramadol (except BM) were qualitatively determined. Autopsy findings and toxicological analyses of the BM suggested that the cause of death could probably be intoxication by TML. It is apparent from the reviewed literature that analysis of TML in the late stages of decomposition of human body is rarely performed. Literature is predominantly focused on animal studies. Thus, TML concentrations analyzed in BM, M, or FL could be found helpful in relation to evaluation of intoxication by this substance. However, the significance of the results obtained in the presented study should be confirmed by further analyses of BM, M, or FL, where TML would be proved in lethal concentration in the blood.

Reduced body length and morphological disorders in Chrysomya albiceps (Diptera: Calliphoridae) larvae reared on aluminum phosphide-treated rabbits

Assessing the time of death based on the growth and development of insects is a critical task in forensic entomology. The rate of larvae development can be affected by a variety of toxins, including pesticides. Aluminum phosphide (AlP) is a low-cost insecticide that has yet to be tested for entomotoxicological significance, despite the fact that it is frequently the cause of fatal poisoning. In this study, we measured the body length of Chrysomya albiceps larvae reared on the carcasses of rabbits poisoned with AlP and analyzed the morphological changes of the larvae reared on the carcasses of rabbits poisoned with AlP. The concentration of AlP in the body of the larvae was significantly lower than in rabbit tissues. Insects from the AlP group had a significantly lower gain in body length. Furthermore, deformities in the larvae were found. Smaller respiratory spiracles were found, as well as a deformed small posterior end with hypogenesis of the posterior respiratory spiracles. Thus, disturbed growth and development of carrion flies found at a crime scene could indicate pesticide poisoning, such as aluminum phosphide.

Forensic entomology research in Egypt: a review article

Background

Forensic entomology (FE) is widely considered as an important field of forensic science, particularly in the field of estimating postmortem intervals, which has advanced considerably across the world.

Main body

Researchers used necrophagous insects in twelve Egyptian governorates to look into the variables that impact insect succession and the growth of juvenile stages from infesting animal models and humans, draw toxicological conclusions, and identify insect species using morphological and molecular-based approaches. The study includes analyses of insect abundance and dispersion, along with biochemical and electrophysiological experiments. Comparable data from other Egyptian governorates, on the other side, is currently unavailable. Aspects of FE are also missing, which might be addressed in a future research project.

Conclusion

This review aims to provide an outline of FE in Egypt, other than to assist existing researchers in identifying research needs and recruiting new researchers into the field by highlighting significant forensic insects that might be employed in criminal prosecutions.

Effects of ante-mortem use of methadone on insect succession patterns

Background

Evaluation of insect succession patterns is a scientific method to estimate the time elapsed since death. Several studies have shown that ante-mortem intake of opioids affect maggot growth rate. However, there are few published data that investigate the effect of ante-mortem opioid use on insect succession patterns.

Therefore, the main purpose of this research was to investigate the effect of methadone on the succession patterns of insects on rabbit carcasses during the spring and winter of 2019. In the present study, the H-null hypothesis represents the dissimilarity between the successional waves of species from testing and control carcasses (H0: P: 0).

Results

During this study, 15 and 13 insect species were collected from carcasses during the spring and winter, respectively. The most dominant species during the both seasons were Chrysomya albiceps and Calliphora vicina. These two species preferred to lay eggs on the control carcasses earlier than the treated carcasses. Lucilia cuprina was observed only from the remains of untreated carcasses, while Saprinus chalcites and Necrobia rufipes were recorded only from the remains of treated rabbits. Samples indicate that 11.8% of the insects were members of the Coleoptera. Permutation analyzes based on the Mantel test were 0.647 ± 0.16 (P = 0.009) and 0.693 ± 0.16 (P = 0.003) for the similarity of the species between treated and untreated carcasses in the spring and winter, respectively. Permutation analyzes for the two most dominant fly species (Ch. albiceps and C. vicina) between the treated and untreated carcasses in the spring and winter were 0.515 ± 0.15 (P = 0.05) and 0.491 ± 0.14 (P = 0.09), respectively.

Conclusion

The results revealed that the overall pattern of insect succession was similar between the treated and untreated rabbit carcasses. However, the patterns of succession of Chrysomya albiceps and Calliphora vicina differed slightly between treated and untreated carcasses, and this could have an effect on the PMI min estimate.