Occurrences of flesh flies (Diptera: Sarcophagidae) on human cadavers in Switzerland, and their importance as forensic indicators

From 1993 to 2008, criminal investigations were conducted in the western part of Switzerland with special attention to blowfly and flesh fly species in order to estimate the post-mortem interval when requested by the police authorities. Flesh flies were found in only 33 cases out of 160. Five species of the genus Sarcophaga were identified (S. africa, S. argyrostoma, S. caerulescens, S. similis and S. sp.). The main species found on corpses (larval stage) was S. argyrostoma. The thermal constant (K) calculated for this species in Switzerland is 380.6 ± 16.3 (mean ± S.D.) degree-days. With the exception of S. caerulescens, found three times in the larval stage on corpses, the three other species are of minor forensic importance. S. argyrostoma is found during summer and indoors. This species colonises dead bodies, usually the same day as blowfly species, and it could be used to estimate the post-mortem interval. Other species are discussed in the light of current knowledge on their biology and ecology. It is recommended that voucher material be deposited in a museum, allowing further studies by relevant specialists, thereby helping investigators and avoiding misidentifications.     

Comparison of insect species associated with decomposing remains recovered inside dwellings and outdoors on the island of Oahu, Hawaii

A comparison of insects collected from 35 cases of decomposing remains on the island of Oahu, Hawaiian Islands (14 from indoor situations and 21 from outdoors), yielded a total of 22 species of insects in 3 orders and 12 families. Of these, five species were recovered in both indoor and outdoor situations. Remains recovered indoors had a greater variety of Diptera larvae associated with them, while remains discovered outdoors had a greater variety of Coleoptera species present. Some species of insects were restricted to remains discovered indoors, while others were found only associated with remains in outdoor situations. Knowledge of the species of insects associated with different habitats may serve to provide information concerning the history of the remains.     

Soil Fungi: Their Potential use as a Forensic Tool

As a grave is an anomalous environment and differs from its surroundings, criminal investigators employ different techniques for locating, recovering, and analyzing clandestine graves. In this study were identified the fungi found in the soil under corpses in decomposition with an aim at relating the copresence of human remains and different fungal species. Were isolated the fungi in three ways: soil washing, serial dilutions, and moist chamber growth. Dichotomomyces cejpii, Talaromyces trachyspermus, Talaromyces flavus, and Talaromyces sp. were the representative species found—with those belonging to the ammonia group, whose fungi are the first in the succession of cadaver decomposition directly in the ground. The mycobiota found at the present study area clearly differs to mycobiota identified in control sample and from previously described species for other areas of Buenos Aires Province, Argentina. Further forensic examples of this type are needed to develop fully the detailed use of mycology as a forensic tool.     

Discovery of decomposed and mummified corpses in the domestic setting--a marker of social isolation?

Mass media reports attribute the occurrence of decomposed or mummified corpses in a domestic setting mainly to an increasing social isolation of elderly people. Not much is known about the demographic and medical conditions under which individuals are found months or even years after death in their homes. For this study, autopsy reports of individuals found dead and mummified or decomposed between 1993 and 1997 with those from 1963 to 1967 were retrospectively analyzed. Between 1993 and 1997, a total number of 320 individuals were found decomposed at home compared to 412 such cases between 1963 and 1967. The proportion of individuals older than 64 years was significantly higher during the 1990s study period. Furthermore, the proportion of deaths attributable to natural causes was significantly lower during the 1990s, whereas the rate of suicides was nearly three times higher.     

Long persistence of rigor mortis at constant low temperature

We studied the persistence of rigor mortis by using physical manipulation. We tested the mobility of the knee on 146 corpses kept under refrigeration at Torino's city mortuary at a constant temperature of +4 degrees C. We found a persistence of complete rigor lasting for 10 days in all the cadavers we kept under observation; and in one case, rigor lasted for 16 days. Between the 11th and the 17th days, a progressively increasing number of corpses showed a change from complete into partial rigor (characterized by partial bending of the articulation). After the 17th day, all the remaining corpses showed partial rigor and in the two cadavers that were kept under observation "à outrance" we found the absolute resolution of rigor mortis occurred on the 28th day. Our results prove that it is possible to find a persistence of rigor mortis that is much longer than the expected when environmental conditions resemble average outdoor winter temperatures in temperate zones. Therefore, this datum must be considered when a corpse is found in those environmental conditions so that when estimating the time of death, we are not misled by the long persistence of rigor mortis.     

Toxicologic survey of findings in putrefied corpses. Corpse putrefaction in air

Autopsies were conducted on 234 putrefied corpses (exposed to the air, not buried) at the Institute for Forensic Medicine of the University of Hamburg from January 1979 to May 1983. Estimating the time it had taken to reach the respective degree of putrefaction was almost impossible. Only anamnestic clues provided evidence to ascertain the approximate time of death (between 3 days and 46 months ago). The cadavers were found in different locations: outdoors, inside heated or non-heated rooms. Some corpses wore clothes; others were naked; some were covered with blankets or other material. Chemicotoxicological analyses consisted of routine methods and additional modern sophisticated techniques: capillary gas chromatography, combined GC/MS, infrared spectrometry, radio- and enzyme-immunological tests. In organ specimens and body fluids of 47 corpses organic medicaments or poisons could be detected. Nearly all of these 47 forensic autopsies were carried out by request of the legal authorities to rule out legal intoxication as well as the influence of illegal drugs or medicaments. Unlike 20 years ago, today it is possible to detect and quantify organic drugs and poisons as well as their metabolic products, especially minor or major tranquilizers or barbiturates, in highly putrefied specimens. In spite of analytical progress, interpretation of some chemotoxicological results remains difficult. Poor anamnestic data provide insufficient clues. Therefore, pathologicoanatomical and histological results have special significance for the final conclusions. Good cooperation between the pathologist and toxicologist is one of the imperative prerequisites to come to a satisfying result.     

A new method of reproduction of fingerprints from corpses in a bad state of preservation using latex

In view of the problems arising while fingerprinting corpses in a bad state of preservation, especially in case of mummification and carbonization, the authors propose an innovative technique which uses latex film. To better illustrate the potential of the method, two cases where the latex technique was applied successfully are reported: the first one is a mummified body discovered in a shack on the outskirts of Milan and the second one is the case of a burnt corpse found in a car boot. Such a technique is versatile, easy to apply, and allows the operator to work quickly on cadavers without amputating parts, except in rare cases (i.e., burnt bodies with muscle retraction). By the latex technique, a perfect and enduring negative copy of the fingerprint is obtained, ready to be inked and photographed. The numerous copies produced this way can be inked several times allowing for the repeatability of the procedure and this is crucial in cases of problematic legal identification of corpses. In both the cases illustrated, the fingerprints obtained by the latex technique were useful for identification. The quality was good enough for the automatic fingerprint identification system research system to be applied.     

The nocturnal oviposition behaviour of blowflies (Diptera: Calliphoridae) in Central Europe and its forensic implications

Numerous factors may cause delayed colonisation of a corpse by blowflies, leading to a discrepancy between the entomologically determined post-mortem interval (PMI) and the time of death. Blowflies, for example, are considered to be inactive at night, however, published observations are contradictory. In the present study, several field experiments and one type of indoor experiment were conducted in summer of 2004 and 2005 in order to investigate the nocturnal ovipositional behaviour of blowflies. In the field, two types of bait, dead hedgehogs and fresh beef liver, were placed at night in different urban and rural locations in Frankfurt and in Munich, Germany. For the indoor-experiments beef liver was placed in small plastic boxes containing caged Lucilia sericata females in the evening and left overnight. At night, no ovipositon was observed in the field (n=51, T=10-24 degrees C). Nocturnal oviposition in complete darkness occurred in the plastic boxes in two of six cases (T=25 degrees C). Considering the behavioural and physiological characteristics of flies we suggest that nocturnal oviposition of blowflies appears to be unlikely under natural conditions in Central Europe but may occur under certain circumstances, such as unusual high nightly temperatures and the presence of gravid flies with an appropriate arousal threshold.     

Deaths among homeless people in Istanbul

The number of the homeless people in Istanbul, one of the largest cities in the world, is at present unknown. There has been no previous study in Turkey on cases and causes of death occurring among these individuals. In this paper, documents and autopsy reports of the Mortuary Section of the Council of Forensic Medicine, Istanbul, covering the period January 1st, 1991-December 31st, 1995, were reviewed. We established that there were 126 cases of death among homeless individuals in Istanbul during this period, 120 of them being males (95%), four (3%) females, and two (2%) transsexuals. Ninety-four corpses were found outdoors, 32 indoors. No personal documents, such as identity cards, were found in 110 individuals (87%), whereas only 16 individuals could be identified. Most deaths occurred in the age group of 41-50 years. One hundred and three of the cases (82%) died in the cold season between October and April. The deaths of 98 cases were attributable to natural causes, whereas the remaining 28 cases died from unnatural causes. Respiratory tract diseases occupied the first rank among cases of death from natural causes (44%). Alcohol abuse and other infections were further striking factors contributing to the fatal outcome. This is the first retrospective study on this topic in Turkey. However, more detailed and anterospectively programmed studies on this subject, a growing social problem, should be carried out.     

Forensic Entomology and the Estimation of the Minimum Time Since Death in Indoor Cases

Eight cases that occurred indoors in which the insects played an important role in the mPMI estimation are presented. The bodies of socially isolated people and old people living alone were discovered in central Italy between June and November. mPMI ranged from a few days to several weeks. Insects were collected during the body recovery and the postmortem. Climatic data were obtained from the closest meteorological stations and from measurements performed on the site. Sarcophagidae and Calliphoridae species were present in 75% of the cases with Lucilia sericata and Chrysomya albiceps collected in 50% of the cases. Chrysomya albiceps was always found in association with Lucilia species. Scuttle flies (Phoridae) were found in 37.5% of the cases, confirming the ability of these species in indoor body colonization. We show that if sealed environment may delay, the insect arrival dirty houses may create the environment where sarcosaprophagous insects are already present.     

The black soldier-fly, Hermetia illucens (Diptera, Stratiomyidae), used to estimate the postmortem interval in a case in Amapá State, Brazil

The black soldier-fly (Hermetia illucens) is a generalist detritivore which is commonly present in corpses in later stages of decomposition and may be useful in forensic entomology. This paper describes the estimation of the postmortem interval (PMI) based on the life cycle of the black soldier-fly in a case in northern Brazil. A male child was abducted from his home and 42 days later his corpse was found in an advanced stage of decay. Two black soldier-fly larvae were found associated with the body. The larvae emerged as adults after 25-26 days. Considering the development cycle of H. illucens, the date of oviposition was estimated as 24-25 days after abduction. Since H. illucens usually (but not always) colonizes corpses in more advanced stages of decay, this estimate is consistent with the hypothesis that the child was killed immediately after abduction.     

Postmortem production of ethanol in different tissues under controlled experimental conditions

The aim of this study was to follow the postmortem ethanol production phenomenon under controlled experimental conditions (temperature, time interval) in different tissues. Specimens of blood, liver, skeletal muscle and kidney were taken from 30 corpses and no chemical preservatives were used in the specimens collected. Ethanol concentrations were detected by gas chromatography. All specimens stored at -20 degrees C and 4 degrees C did not show any change in ethanol concentration in an eight-day time interval. At 20 degrees C and 30 degrees C, all tissues, except blood, showed statistically significant ethanol production over the time interval tested. However, blood sample kept at 30 degrees C, showed statistically significant increase in ethanol production on the 2nd and 4th day comparing to the controls. Thus, we can state that postmortem ethanol production occurs in different tissues, and is increased at higher temperatures and, in general, it is in accordance with the course of time.     

Delimitation of the time of death by immunohistochemical detection of insulin in pancreatic beta-cells

To improve the possibilities to delimitate the time of death after longer laytime, it was examined if this is possible by immunohistochemical insulin detection. The results show that in our examination material, the pancreatic beta-cells of up to 12-day-old corpses produce a positive immunoreaction towards insulin in all cases, whereas none of the corpses older than 30 days show such a reaction. This means that in case of a negative immunoreaction, the time of death can be assumed to lie more than 12 days before the autopsy. The fact that a negative immunoreaction occurs consistently after 30 days leads to the conclusion that when insulin has been stained in a specimen, the death of the respective person must lie a maximum of 29 days earlier, whereby these time-limits may change in considerably different surrounding conditions.     

Seasonal patterns of arthropods occurring on sheltered and unsheltered pig carcasses in Buenos Aires Province (Argentina)

Differences in the succession of insects and other Arthropoda (invertebrate animals with jointed legs), on domestic pig carcasses placed under a roof and under the open sky have been studied in Buenos Aires Province, Argentina (latitude 34 degrees 45'S) in all the seasons of the year. Faunal associations proved different for each treatment in winter: the common bluebottle Calliphora vicina was found in both, but on the sheltered carcass Cochliomyia macellaria and the rare Phaenicia cluvia were found as well. In the fall, the difference between sheltered and unsheltered carcasses was small (six species on the former and five species on the latter); in spring and summer, the difference was negligible.     

Quantitative Analysis of the DNA Distribution on Cigarette Butt Filter Paper*

The distribution of DNA on the filter paper of smoked cigarette butts was quantitatively mapped using real‐time quantitative polymerase chain reaction. The filter papers from smoked cigarette butts collected from indoor and outdoor sources were sliced into equal pieces and the amount of DNA on each slice was determined. This study found that the cigarette butt filter papers sliced parallel to the seam of the cigarette had more uniformly distributed DNA on the slices and in most cases, there was enough DNA on each slice to obtain a complete DNA profile. The perpendicular slices had a less uniform pattern of distribution and some slices did not have enough DNA to obtain an interpretable DNA profile. Cigarette butts found indoors also had more DNA per cigarette on average than cigarette butts found outdoors.     

Use of PCR-RFLP for differentiation of calliphorid larvae (Diptera,Calliphoridae) on human corpses

Blowfly larvae found on human corpses are important for the estimation of the postmortem interval (PMI) and other questions of forensic relevance. Some of these species are difficult to differentiate morphologically, therefore a molecular method was elaborated for species identification. Specific fragments of the COI and COII region of the mitochondrial DNA (mtDNA) were amplified followed by digestion with different restriction enzymes. Using a 1.3 kb fragment, identification of Lucilia sericata, Calliphora vicina and Calliphora vomitoria was possible by digestion with only one restriction enzyme using either DraI or HinfI. Furthermore, we sequenced 349 bp (a part of the COI and COII regions) from the same three species and found 34 nucleotide distinctions between C. vicina and L. sericata, 30 between C. vomitoria and L. sericata and 15 between the two Calliphora species. These results aid in quick identification of species used for estimation of PMI.     

北京地区法医昆虫学研究──Ⅱ.尸体分解过程中的昆虫种类演替与死亡时间推断

在调查北京地区嗜尸性昆虫物种谱系的基础上，进一步研究了在尸体分解过程中，昆虫种类的演替特点及其对死亡时间推断的价值。嗜尸性昆虫侵食尸体的过程可分为侵入期、分解期和残余期：侵入期以双翅目蝇类为主，时间推断以幼蛆的发育程度为依据；分解期出现大量鞘翅目种类，时间推断以甲虫的各类组成、数量以及演替特征为主要依据；残余期昆虫数量极少。季节及温度、环境条件、尸体是否受伤或裸露，是影响昆虫侵食尸体时序的三个重要因素。正常的春季，侵入期为8至25天，分解期为约42天。     

The forensic application of allozyme electrophoresis to the identification of blowfly larvae (Diptera: Calliphoridae) in southern Australia

Most known carrion-breeding species of blowflies in southern Australia are of the genus Calliphora. The morphological similarity of the immatures of these species means that correctly identifying them poses a challenge for forensic entomologists. This study investigates the potential of allozyme analysis to assist with this task. Molecular profiles of third-instar larvae and adults representing four of these carrion-breeding species, Calliphora stygia, C. dubia, C. hilli hilli, and C. vicina, were compared at 42 allozyme loci. The two life stages were found to display almost identical allozyme profiles in each species (93% of loci were expressed in both life history stages), enabling the reliable identification of larvae in these four species. Integration of these results with data from a previous study indicates that allozyme analysis would also be suitable for rapid, species-level identification of the larvae of six other carrion-breeding Calliphora species occurring in southern Australia. This is the first report of the application of allozyme data to the identification of forensically important blowflies.     

The utility of mitochondrial DNA sequences for the identification of forensically important blowflies (Diptera: Calliphoridae) in southeastern Australia.

The applicability of mitochondrial DNA (mtDNA) sequencing was investigated for the identification of the following forensically important species of blowflies from southeastern Australia: Calliphora albifrontalis, C. augur, C. dubia, C. hilli hilli, C. maritima, C. stygia, C. vicina, Chrysomya rufifacies, Ch. varipes and Onesia tibialis. All breed in carrion except O. tibialis, which is an earthworm parasitoid. Emphasis was placed on Calliphora species because they predominate among the carrion-breeding blowfly fauna of southern Australia and their immatures are difficult to identify morphologically. A partial sequence of the mitochondrial COII gene was determined for all species and for COI for C. albifrontalis, C. augur, C. dubia and C. stygia only. Five other species of blowflies, Chrysomya albiceps, Ch. rufifacies, Protophormia terraenovae, Lucilia illustris and L. sericata, for which sequence data were already available, were also included. Analysis of the COI and COII sequences revealed abundant phylogenetically informative nucleotide substitutions that could identify blowfly species to species group. In contrast, because of the low level of sequence divergence of sister species, the data could not distinguish among taxa from the same species group, i.e. the species within the C. augur and C. stygia groups. The molecular data support the existing species group separation of the taxa within Calliphora. Because of the speed and accuracy of current nucleotide sequencing technology and the abundant apomorphic substitutions available from mtDNA sequences, this approach, with the analysis of additional taxa and genes, is likely to enable the reliable identification of carrion-breeding blowflies in Australia.