The colonisation of remains by the muscid flies Muscina stabulans (Fallén) and Muscina prolapsa (Harris) (Diptera: Muscidae)

Species Composition and Succession of Necrophagous Insects on Small Buried Baits in China

The postburial interval (PBI) can be inferred by using necrophagous insects colonizing the buried corpse. In different seasons, the species composition and succession of necrophagous insects on swine carrion (0.5-0.75 kg) buried at the depths of 30 cm and 60 cm in a Populus alba var. pyramidalis (Bunge, 1854) (Salicales: Salicaceae) grove of Shenyang, China from 2017 to 2019 were investigated. A total of 21 species of necrophagous insects belonging to 5 orders, 17 families were collected. Among them, the species of Phoridae and Platystomatidae were dominant at burial depth of 30 cm and 60 cm in summer and autumn. The species composition and time of colonization of necrophagous insects on the buried baits varied with seasons. Platystoma mandschuricum (Enderlein, 1937) (Diptera: Platystomatidae) and Aleochara puberula (Klug, 1833) (Coleoptera: Staphylinidae), the first arriving insects in spring, occurred on the baits for the longest time, from early June to early December. This work could provide reference data for the PBI estimation in Shenyang and similar geographical areas.

It is all about the insects: a retrospective on 20 years of forensic entomology highlights the importance of insects in legal investigations

This study highlights the importance of insect evidence by evaluating 949 insect-associated cases, including 139 entomological reports, from 2001 to 2019 at the Institute of Legal Medicine Frankfurt/Germany. With a high number of cases in the summer months and a low number in the colder season, 78.5% of the bodies were found indoors, regardless of year or month. In more than 80% of the cases, where PMI information was available (n = 704), the presumed PMI ranged from 1 to 21 days, a period during which entomological evidence can provide a day-specific estimate of PMI_min. In cases where insects have been identified to species level (n = 279), most bodies were infested by one or two species with a maximum of 10 different species. Overall, a total of 55 insect species were found. Information on biology, activity and distribution of the most abundant taxa is given and applied for 5 case histories estimating different PMI_mins of up to over 6 months. Despite proved importance and scientific development of forensic entomology, insects are still rarely considered as a tool in forensic case work. The main reasons are a lack of awareness and (too) late involvement of a forensic entomologist. Our work shows that forensic entomology is an independent discipline that requires specialist expertise.

Decomposition process for buried rat (Rattus norvegicus, Berkenhout 1769) carcasses in Riyadh city, Saudi Arabia: A preliminary study

The present report outlines the initial observations from an ongoing study examining the decomposition rate of buried rat (Rattus norvegicus, Berkenhout 1769) carcasses in Riyadh city, Saudi Arabia. Eight rat carcasses were buried in separate holes at depths of 20 and 40 cm (four holes per depth) to allow natural decomposition and examined at 10-day intervals up to 40 days. During the study period, environmental factors such as humidity, soil temperature, and air temperature were monitored at each depth on a daily basis. At the end of each burial period, one carcass from each depth was exhumed and the degree of decay and presence of insect activity were examined. The results showed that burial depth and temperature were major factors affecting the decomposition rate, whereas no insect activity was observed. The findings of this study can be used to more accurately estimate the time since burial of carcasses.

Investigations on Arthropods Associated with Decay Stages of Buried Animals in Italy

Simple Summary

The burial of corpses may interfere with the succession of sarcosaprophagous fauna and forensic evaluation of post-mortem interval. For the first time in Italy, an experimental study was conducted on arthropods associated with buried pig carcasses in a rural area near Cosenza (Southern Italy). One carcass was left above the ground and five were buried: one of the buried ones was periodically exhumed to evaluate the effects of disturbance on decay processes and on arthropod fauna, and the other four were exhumed only once at given time intervals. The results revealed differences in taxa and colonization of arthropod fauna in the above ground and periodically exhumed carcasses. No arthropod colonization was detected in the carcasses exhumed only once, showing that a burial at about 25 cm depth could be sufficient to prevent colonization by sarcosaprophagous taxa.

Abstract

Burial could be used by criminals to conceal the bodies of victims, interfering with the succession of sarcosaprophagous fauna and with the evaluation of post-mortem interval. In Italy, no experimental investigation on arthropods associated with buried remains has been conducted to date. A first experimental study on arthropods associated with buried carcasses was carried out in a rural area of Arcavacata di Rende (Cosenza), Southern Italy, from November 2017 to May 2018. Six pig carcasses (Susscrofa Linnaeus) were used, five of which were buried in 60-cm deep pits, leaving about 25-cm of soil above each carcass, and one was left above ground. One of the buried carcasses was periodically exhumed to evaluate the effects of disturbance on decay processes and on arthropod fauna. The other four carcasses were exhumed only once, respectively after 43, 82, 133, and 171 days. As expected, the decay rate was different among carcasses. Differences in taxa and colonization of arthropod fauna were also detected in the above ground and periodically exhumed carcasses. In carcasses exhumed only once, no arthropod colonization was detected. The results showed that a burial at about 25 cm depth could be sufficient to prevent colonization by sarcosaprophagous taxa and these data could be relevant in forensic cases involving buried corpses.

Characterizing forensically important insect and microbial community colonization patterns in buried remains

During violent criminal actions in which the perpetrator disposes of the victim's remains by burial, the analysis of insects and bacterial colonization patterns could be necessary for postmortem interval (PMI) estimation. Our research aimed to assess the decomposition process of buried rat carcasses from shallow graves (40 cm), the diversity and dynamics of insects and bacteria throughout the decomposition stages, and the environmental parameters' influence on these variations. The results provide further insight on decomposition in soil and contribute to a broader understanding of the factors involved in decomposition by qualitatively and quantitatively analysing the decomposer community (bacteria and insects). Additionally, two bacterial taxa, Enterococcus faecalis and Clostridium paraputrificum that were investigated for the first time as PMI indicators using quantitative polymerase chain reaction (qPCR) showed differential abundance over time, promising data for PMI estimation. The current study on the decomposition of buried rat carcasses in a natural environment will strengthen the current knowledge on decomposed remains from shallow graves and represents an effort to quantify insect and bacterial taxa as PMI estimators.

New records of forensic entomofauna in legally buried and exhumed human infants remains in Buenos Aires, Argentina

The study of carrion fauna associated with buried human corpses from a forensic perspective could provide useful information in criminal investigations. Insects and other arthropods remains sampled of 44 legally exhumed infant skeletons from La Plata (Buenos Aires, Argentina). They were identified at different taxonomic levels depending on the state of preservation. The specific diversity, abundance and frequency were analyzed and each taxon was assigned to the hypothetical colonization sequence: burial colonization, post-exhumation contamination at cemetery deposit or soil fauna. The phorid Dohrniphora sp. is mentioned for the first time in Argentina as carrion fauna of underground colonization, and the assemblage of Dohrniphora sp., Megaselia scalaris and Hydrotaea aenescens is proposed as indicator of buried cadavers. These findings provide new useful data to be applied in forensic entomology research.