A taphonomic examination of inhumed and entombed remains in Parma cemeteries, Italy

People of different cultures bury their dead in different ways, based on religious beliefs, historical rituals, or public health requirements. In Italy, cremation is still a limited practice compared to entombment and inhumation. Accordingly with the law, a buried body can be moved to the cemetery ossuary only if skeletonized. Generally, complete skeletonization occurs within 40 years following burial, but sometimes the body may mummify, or it may turn into adipocere. Globally, today burial space is limited with cemeteries facing a growing need for both burials and entombments. The present study considered the thanatological, taphonomical, anthropological, microbiological and geochemical examination of 408 human bodies exhumed from grave pits and stone tombs located in two cemeteries in Parma, Italy. Intrinsic and extrinsic factors associated with the process of the decomposition of such bodies were documented in order to identify which factors promote or reduce the time needed for skeletonization. Overall, the aim of this study was to improve the management of the body turnover in cemeteries, providing recommendations for cemetery management and turnover planning, with the goal of avoiding extra costs that may be attributed to the family and the State. The results of this study show that inhumation in burial grounds and soils with a high percentage of sand and gravel promote decomposition and skeletonization, whereas entombments inside stone tombs and the presence of stone slabs on the ground covering burials, aid in the formation of adipocere, slowing down the decomposition process

Barnacle colonization of shoes: Evaluation of a novel approach to estimate the time spent in water of human remains

Estimating the time since death (minimum Post Mortem Interval, minPMI) is a necessary part of a forensic investigation. Besides considering the typical signs of death, minPMI can be estimated using the insects and other arthropods that colonize the remains (forensic entomology). In an aquatic environment, both insects and crustaceans may provide information regarding the time spent in water of the remains (minimum Floating Interval, minFI and minimum Post Mortem Submersion Interval, minPMSI), and this can also assist in determining the minPMI. Barnacles (Crustacea: Cirripedia) are common crustaceans that colonize solid substrates in marine environments and they can be found in association with organic and inorganic remains recovered from the sea. Barnacles colonize both floating and submerged remains and their growth rate is temperature dependent. Despite their potential to be indicative of the minFI and/or minPMSI, only a few case studies have considered it for this purpose, and scant research has been conducted in this field. Assuming that the vast majority of the bodies found in the sea are clothed, this research is focused on the barnacle colonization of two different types of shoes placed in the sea, in order to 1) identify the colonizing species in the chosen environment; 2) identify the settlement preferences of the barnacles associated with the shoes; and 3) determine the factors affecting the growth rate of the barnacles associated with the shoes. In April 2016 64 sport shoes (SS) and 64 patent leather shoes (PLS) were placed in the Boston Harbor (MA-USA) at 8/10 meters below sea level. Four of each shoe type were collected every two weeks for seven months. Individual barnacles from each shoe were sampled and measured to determine species and age. The overall colonization density and settlement preference was statistically analyzed. Results show that a) Amphibalanus improvisus (Darwin) (Crustacea: Cirripedia: Sessilia) colonized the vast majority of shoes; b) colonization occurred in less than 30 days and continued throughout the research period; c) a significant difference in colonization densities was found between the SS and PLS, with PLS seeing higher densities; d) barnacles showed preferential colonization of specific sections on both shoe types; e) barnacle growth was found to be significantly affected by water temperature and shoe type but not by the time spent in water; f) time spent in water and shoe type had a highly significant effect on the total number of barnacles per shoe, whereas water temperature did not

Insect succession pattern on decomposing swine carcasses in Tasmania: A summer study

Insect succession has been studied around the world using the predictable and mostly sequential arrival pattern of different insect species that are attracted to a decomposing carcass. In cases of suspicious death of humans and animals, carrion insects may be used to assist in crime scene reconstruction. The present research represents the first study in forensic entomology to be undertaken in Tasmania, investigating insect succession patterns on decomposing pig carcasses and providing a preliminary database of forensically important insects. Six pig carcasses were placed in two contrasting locations (rural and urban) in northern Tasmania. Insect successional waves were recorded over a 40-day study during the austral summer season. Results showed that decomposition rates and insect assemblages varied between each location. Eleven insect taxa, representing nine families, were identified in association with the decomposition of the pig carcasses at both localities. Blowflies present on the pig carcasses throughout the decomposition process were Calliphora stygia Malloch (Diptera: Calliphoridae) at both sites and Lucilia sericata (Meigen) at the urban site only. These preliminary results will provide useful information in any future casework involving human remains and associated insect material in Tasmania

Chasing Flies: The use of wingbeat frequency as a communication cue in Calyptrate Flies (Diptera: Calyptratae)

The incidental sound produced by the oscillation of insect wings during flight provides an opportunity for species identification. Calyptrate flies include some of the fastest and most agile flying insects, capable of rapid changes in direction and the fast pursuit of conspecifics. This flight pattern makes the continuous and close recording of their wingbeat frequency difficult and limited to confined specimens. Advances in sound editor and analysis software, however, have made it possible to isolate low amplitude sounds using noise reduction and pitch detection algorithms. To explore differences in wingbeat frequency between genera and sex, 40 specimens of three-day old Sarcophaga crassipalpis, Lucilia sericata, Calliphora dubia, and Musca vetustissima were individually recorded in free flight in a temperature-controlled room. Results showed significant differences in wingbeat frequency between the four species and intersexual differences for each species. Discriminant analysis classifying the three carrion flies resulted in 77.5% classified correctly overall, with the correct classification of 82.5% of S. crassipalpis, 60% of C. dubia, and 90% of L. sericata, when both mean wingbeat frequency and sex were included. Intersexual differences were further demonstrated by male flies showing significantly higher variability than females in three of the species. These observed intergeneric and intersexual differences in wingbeat frequency start the discussion on the use of the metric as a communication signal by this taxon. The success of the methodology demonstrated differences at the genus level and encourages the recording of additional species and the use of wingbeat frequency as an identification tool for these flies

The effect of antifreeze (ethylene glycol) on the survival and the life cycle of two species of necrophagous blowflies (Diptera: Calliphoridae)

Entomotoxicology involves the analysis of the presence and the effects of toxicological substances in necrophagous insects. Results obtained by entomotoxicological studies may assist in the investigation of both the causes and the time of death of humans and animals. Ethylene glycol (EG) is easy to purchase, sweet and extremely toxic. It may be consumed accidentally or purposefully, in an attempt to cause death for suicidal or homicidal intent. Several cases report fatalities of humans and animals. The present study is the first to examine the effects of EG on the survival, developmental rate and morphology of two blowfly species, (Diptera: Calliphoridae) typically found on corpses and carcasses: Lucilia sericata (Meigen) and L. cuprina (Wiedemann). Both species were reared on substrates (beef liver) spiked with three different concentrations of EG that could cause death in either a human or cat: 1/2LD50 (T1), LD50 (T2), 2LD50 (T3), in addition to a control treatment (C) with no EG. Results of this research show that: a) both species are unable to survive if reared on a food substrate spiked with the highest concentration of EG (T3), while lower and medium concentrations (T1, T2) affect, but not prevent, the survival and the completion of the life cycle of such species; b) adults of L. sericata eclose only in C and T1, while adults of L. cuprina in both C, T1, T2; however, c) the developmental time of both species reared in T1 and T2 is statistically slower than the control; d) the body length of the immatures of both of the species reared in T1 and T2 is statistically smaller than the control

Development and validation of a GC–MS method for nicotine detection in Calliphora vomitoria (L.) (Diptera: Calliphoridae)

Entomotoxicology is the application of toxicological methods and analytical procedures on necrophagous insects feeding on decomposing tissues to detect drugs and other chemical components, and their mechanisms affecting insect development and morphology and modifying the methodology for estimation of minimum time since death. Nicotine is a readily available potent poison. Because of its criminal use, a gas chromatography-mass spectrometry (GC-MS) method for the detection of nicotine in Calliphora vomitoria L. (Diptera: Calliphoridae) was developed and validated. Furthermore, the effect of nicotine on the development, growth rate, and survival of this blowfly was studied. Larvae were reared on liver substrates homogeneously spiked with measured amounts of nicotine (2, 4, and 6 ng/mg) based on concentrations that are lethal to humans. The results demonstrated that (a) the GC-MS method can detect both nicotine and its metabolite cotinine in immature C. vomitoria; (b) the presence of nicotine in the aforementioned three concentrations in food substrates did not modify the developmental time of C. vomitoria; (c) during the pupation period, larvae exposed to nicotine died depending on the concentration of nicotine in the substrate; and (d) the resultant lengths of larvae and pupae exposed to 4 and 6 ng/mg concentrations of nicotine were significantly shorter than those of the control

Genetic structure of the Bovicola ovis (Mallophaga: Trichodectidae) in Southwestern Australia

The sheep biting louse, Bovicola ovis (Schrank), is an economically important, worldwide ectoparasite of sheep. In Australia, up to 30% of sheep flocks are infested with lice. The usual method of control has been synthetic pyrethroids applied as pour-on along the back of the sheep, but treatment failures have become widespread since 1985 because of the development of resistance. We used allozyme markers to study the distribution of genetic variation within and among populations of lice on different farms in Western Australia. Genetic variation within populations was similar to previously reported values for other ectoparasitic arthropods. Heterozygote deficiencies were found at 1 locus in a number of population and another 2 loci in 1 other population. However, another variable locus conformed to Hardy-Weinberg equilibrium and there was little evidence of extensive linkage disequilibrium between loci. Further studies are necessary to establish the breeding system. Genetic differences among populations were not related to geographic separation, which is consistent with an island model of population structure. A small but significant proportion (2.8%) of the total genetic variation was distributed among populations' equivalent under the island model to a gene flow of 8.7 individuals exchanged per generation. The implications of this result are discussed in terms of controlling and managing synthetic pyrethroid resistance in sheep biting lice

Effects of cooling on the thermal accumulation of heat on the development of the fly Lucilia sericata (Meigen) - Preliminary results

The “best practice in forensic entomology” in collecting immature specimens recommends to “store the majority of individuals […] under controlled conditions; cool temperatures are the most suitable (2-6°C). […] The living samples should be transferred to an expert for processing within 24h” (Amendt et al., 2007). This situation is often not possible and sometimes insects can be found later on the corpse after being kept in a cool room for a number of days depending on the public prosecutors discretion. The aim of this work is to investigate the growth and development of different components of the life history of the cosmopolitan necrophagous fly species Lucilia sericata, Meigen (Diptera: Calliphoridae) in a cold environment (refrigeration approximately 4°C). This study will attempt to interpret the effects of this cooling period calculating the time to accumulate thermal units between control and cooled immature stages. The experimental work was conducted at the Centre for Forensic Science (CFS) at University of Western Australia. The experimental work was divided into experimental sessions comprised of different storage conditions of immature stages of small and large masses of larvae with or without food; over long and short period of time either in the fridge or in and out the fridge for different periods of time. The aim of the experimental work was to determine the rate of survival of immature stages in each of the experimental sessions as well as the modification of the rate of growth and any morphological modification of each life history stage. Currently work has been completed for the session concerning the effect of cooling on eggs, larvae and pupae on no substrate. The statistical analyses performed were: descriptive statistics, One Way ANOVA, TUKEY Test, ANOVA with orthogonal contrasts, Logistic Regression. Statistics and Data Analysis tools: Microsoft Excel, JMP. Preliminary results to date: lower temperatures affect the development of L. sericata; concerning survival rate, older stages of the life history of L. sericata are less affected by cooling; eggs just laid cannot survive the thermic stress of cold temperatures. A number of days in the fridge will arrest the development of Lucilia sericata and will be unable to complete its life cycle. Total ADH out of fridge vs refrigerated samples are in general significantly slower to develop than the controls, in particular in all stages prior to reaching the pupal instar. Thermic stress can modify the growth rate but it seems that the overall growth rate itself is not influenced by the amount of thermic stress duration