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

The Effect of Soil Type and Moisture on the Development of Forensically Important Megaselia scalaris and Dohrniphora cornuta (Diptera: Phoridae)

Necrophagous phorid flies are common insects found on buried corpses, and their developmental data play a crucial role in estimating the post-burial interval (PBI). This study aimed to investigate the effects of soil type and moisture content on some life cycle parameters of two forensically important insects, Megaselia scalaris (Loew, 1866) and Dohrniphora cornuta (Bigot, 1857) (Diptera: Phoridae). Larval and pupal survival, development time, and larval body length of M. scalaris and D. cornuta were observed in three different soil types (loamy sand, sandy loam A, and sandy loam B) with six moisture contents (0%, 20%, 40%, 60%, 80%, and 100%). The results indicated that soil types, soil moisture, and their interaction significantly influenced the growth and development of both species, with moisture being the most influential factor. In each soil, 20% and 40% moisture contents were more suitable for their growth and development. Both the development time and maximum larval body length were significantly different among soil types and moisture contents. The larval period of both species lasted the longest in all soils with 0% moisture content. Additionally, a regression analysis of the relationship between larval body length and development time was performed at different moisture contents in three soils. This study expanded our knowledge of the factors that influence the development of necrophagous insects and provided some reference data for applications of M. scalaris and D. cornuta in PBI estimation.

Insect Colonisation and the Decomposition Process in Aerated versus Watertight Burial Systems

In recent years, burial systems have covered increasingly higher costs due to the pollution caused by decomposition products. These products are understood as chemicals and microorganisms in the surrounding soil and groundwater and represent a topical issue. The purpose of this research was to ascertain the extent of decomposition when pig carcasses are buried in two different burial systems ("aerated" vs. "watertight") and catalogue the arthropods associated with burials at different time-points of removal from niches (after 6, 12, 24, 36, and 60 months). Thirteen taxa were collected in aerated niches, whereas five were collected in watertight niches. The initial access or exclusion of insect colonisers affected overall functional activity. Two Diptera species, Hydrotaea capensis and Megaselia scalaris, were the most abundant, supporting the hypothesis that insects can colonise carcasses in aerated burial systems. Furthermore, some species of bacteria have been documented as facilitators of the initial decomposition process of the carcass. Most bacterial colonies develop only in aerated niches. The trial showed that the first enzymatic-bacterial and insect actions helped promote the process of cadaveric decomposition and later skeletonisation, mainly when associated with aeration modes of the tomb/mound. The results obtained provide essential information on the process of human decomposition and taphonomy in cemeteries. Moreover, these data could benefit forensic science by adding information on insect colonisation and body modification in medico-legal investigations concerning the post-mortem interval in exhumed bodies and illegal burials.

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.

Assemblages of Acari in shallow burials: mites as markers of the burial environment, of the stage of decay and of body-cadaver regions

The burial of a cadaver results in reduced arthropod activity and disruptions in colonisation patterns. Here, the distribution and diversity of mite taxa was studied across decomposition stages of shallowly buried pig carcasses (Sus scrofa domesticus). In total 300 mites (88 species) were collected from three pig shallow graves compared to 129 mites (46 species) from control (bare) soil samples at the same depth. A successional pattern of Acari higher taxa and families was observed, and species richness and biodiversity fluctuated throughout decomposition, whereas active decay showed the greatest biodiversity. Mesostigmata mites were the most abundant in 'cadaver soils' with a significant difference in the abundance of Parasitidae mites, whereas Oribatida mites (true soil mites) were the most abundant in control soils. Certain mite species were significantly associated with decay stages: Cornigamasus lunaris with 'bloated', Gamasodes spiniger with 'active', Eugamasus sp. and Lorryia reticulata with 'advanced', and Macrocheles matrius and Ramusella clavipectinata in 'dry'. Scheloribates laevigatus was a marker of bare soil at a shallow depth and Vulgoramasus remberti of buried decomposition, not specific to any decay stage. Analysis of mite assemblages associated with head, torso and posterior body showed that Parasitus evertsi and M. matrius are attracted to beneath the thighs, whereas L. reticulata to beneath the head. This study highlights the value of mites as indicator species of decomposition and its stages, confirming (1) a succession of Acari on buried remains and (2) species specificity to body regions.

Insect faunal succession on buried goat carcass in Aligarh Region of Uttar Pradesh, India, with implications in forensic entomology

Background

Studies on the insect fauna of animal corpses, used as a vertebrate model, may help forensic investigation cases to estimate the post-mortem-interval (PMI), cause of death, and crime-scene location. Likewise, entomofauna of buried corpses can assist in determining the post-burial-interval (PBI), movement of the body or hiding of the crime. The bodies buried under the soil decompose at a slower rate than the body exposed. Also, there are fewer insects that can go underground to locate the corpse. Such types of studies on the insect fauna of buried carrion can help in forensic investigation cases. The current study aims to determine the succession of a goat carcass buried shallowly in an outdoor habitat of the Aligarh Region, North India.

Results

In the present study, we examined a goat carcass buried at a depth of nine inches to determine the type of insects capable of colonizing buried animal carcass in the study area of Aligarh, Uttar Pradesh, India. We have found five species of Diptera, three species of Coleoptera, one Hemipteran species, and one Hymenopteran species. Adult Dipterans found during different samplings were Megaselia scalaris (Loew 1866), Chrysomya megacephala (Fabricius 1794), and Calliphora vicina (Robineau-Desvoidy, 1830). Dipterans’ immature stages were found to be of Synthesiomyia nudiseta (van der Wulp, 1883) and Hydrotaea capensis (Wiedemann, 1830) Megaselia scalaris. Adults of Saprinus quadriguttatus (Fabricius, 1798), Saprinus splendens (Paykull, 1811), and Onthophagous quadridentatus (Fabricius, 1798) of order Coleoptera. Adult Cydnus species (Fabricius, 1803) of Hemiptera and Dorylus species (Fabricius, 1793) of Hymenoptera have also been recorded. During the sampling, the authors reported the stages of carcass disintegration and the insects associated with it.

Conclusions

Flies, beetles, and ants have been recorded in association with the buried goat carcass, which may add to the knowledge of colonization of buried bodies in India and around the globe. S. nudiseta, H. capensis, and M. scalaris, which are found on the goat carrion in the current study, have also been reported on human corpses in the past. Furthermore, M. scalaris found consistently on two sampling dates beneath the ground on the goat carcass and was also seen running on the grave’s surface. In addition, authors have reported several species belonging to different order and families, corresponding to various stages of decomposition of corpse which were earlier not known from buried corpses from India. So, it is crucial and may have implications in medicolegal cases.