A preliminary study of forensic entomology in Medellín, Colombia.

This is the first report of an ongoing study of insect succession on carrion carried out in Medellín, Colombia, using pigs (Sus scrofa) as a model to determine the insect sequence over 207 days. During this period, 2314 insects belonging to the following orders and families were collected: Diptera: Calliphoridae, Muscidae, Piophilidae, Sarcophagidae, Syrphidae, Otitidae; Hymenoptera: Apidae, Formicidae, Halictidae, Mutilidae, Vespidae; Coleoptera: Staphylinidae, Histeridae, Carabidae, Scarabaeidae, Silphidae, Dermestidae, Cleridae, Nitidulidae; Dermaptera: Forficulidae; Hemyptera: Gelastocoridae, Coreidae; Lepidoptera: Hesperiidae.Five decomposition stages were observed (fresh, bloated, active decay, advanced decay, and dry remains) and four insect ecological categories (necrophagous, predators, omnivorous, and incidental). During the fresh stage, the first insects that appeared were flies of the families Sarcophagidae and Muscidae and specimens of Formicidae (Hymenoptera). During the bloated period, species of Calliphoridae (Diptera) were predominant and the first to oviposit. During the third and fourth stages (active decay and advanced decay), the most abundant families were Calliphoridae and Muscidae, although Staphilinidae (Coleoptera) also stood out. During the last stage (dry remains), the dominant family was Formicidae (Hymenoptera) followed by Dermestidae (Coleoptera) with a large number of immature insects.     

Insect faunal succession on decaying rabbit carcasses in Punjab, India

Insect faunal succession on decaying rabbit carcasses was carried out at Punjabi University, Patiala (Punjab), India, from March 1997 to December 1999. Four stages of decomposition were recognized, i.e., fresh, bloated, decay, and dry. A total of 38 insect species belonging to four orders and 13 families were recorded. Diptera, Coleoptera, and Hymenoptera dominated the carrion fauna. Calliphorids were the first to arrive in all the seasons of the year. Five species of Calliphoridae, four of Sarcophagidae, ten of Muscidae, and one each from Anthomyiidae and Otitidae were observed on rabbit carcasses. Representatives of six Coleopteran families, i.e., Staphylinidae, Histeridae, Cleridae, Dermestidae, Tenebrionidae, and Silphidae, were recorded. Eight species belonging to family Formicidae (Hymenoptera) were also collected during the present studies. Only one species of Lepidoptera was observed on carrion.     

Molecular identification of forensically important fly species in Spain using COI barcodes

Species identification with DNA barcodes has been proven to be effective on different organisms and, particularly, has become a routinely used and quite accurate tool in forensic entomology to study necrophagous Diptera species. In this study, we analysed 215 specimens belonging to 42 species of 17 genera, from 9 different Diptera families. Flies were collected in 39 Spanish localities of the Iberian Peninsula sampled across three years in the four seasons. Intraspecific variation ranged from 0 to 2.46% whereas interspecific variation fluctuated from 3.07 to 14.59%, measuring 651 pb of the cytochrome oxidase subunit one (COI) gene. Neighbour-Joining analysis was carried out to investigate the molecular identification capabilities of the barcoding region, recovering almost all species as distinct monophyletic groups. The species groupings were generally consistent with morphological and molecular identifications. This work, which is the first with this intensive and extensive sampling in this area, shows that the COI barcode is an appropriate marker for unambiguous identification of forensically important Diptera in Spain.     

应用mtDNA COI基因序列鉴别常见嗜尸性蝇类种属

目的探讨mtDNA基因序列对常见嗜尸性蝇类的种属鉴别应用价值。方法收集不同区域2科4属6个种30个蝇类样本,提取样本线粒体DNA后扩增COI基因序列,以琼脂糖电泳检测扩增产物并测序,以DNAMAN6.0分析软件分别截取498bp序列,用MEGA5.2软件分别进行序列分析,然后构建系统发育树,比较各地区不同种属样本的序列差异。结果 6个种属的嗜尸性蝇类30个样本mtDNA的COI基因具有一定的序列差异,种内进化分歧均数在0.1%~1.6%之间,种间进化分歧均数在2.2%~11.2%之间,6个种属通过系统发育树均可明确区分。结论 COI基因序列分析和系统发育树对嗜尸性蝇类的种属检验具有重要帮助作用,可用于现场样本的准确、快速种属鉴定。     

Initial study of arthropods succession and pig carrion decomposition in two freshwater ecosystems in the Colombian Andes

Entomological succession and trophic roles of arthropods associated with different stages of carcass decomposition were studied to estimate the post-mortem submersion interval in two freshwater ecosystems in the Colombian Andes, at an altitude of 2614 m. Pig carcasses were employed as models placed 68 m apart, one in a stream (lotic) and another in an artificial lake (lentic). Decomposition time to skeletal remains was 74 days in the lake and 80 days in the stream. Six phases of decomposition were established: submerged fresh, early floating, floating decay, bloated deterioration, floating remains and sunken remains. A total of 18,832 organisms associated with the carcasses were collected: 11,487 in the lake (four orders, 19 families and 33 species) and 7345 in the stream (eight orders, 15 families and 25 species). Organisms were classified in the following ecological categories: shredders, collectors, predators, necrophagous, sarcosaprophagous and opportunists. Physical and chemical properties of the habitats, such as water temperature, CO(2) and conductivity, varied according to rainfall. In the lake, shredders (Coleoptera: Tropisternus sp. and Berosus sp.) and collectors (Diptera: Chironomus sp.) were found to be associated with submerged phases. Predators (Odonata) were only present during the first phases. Coleoptera (Dytiscidae) were found during floating decay and bloated deterioration stages. In the stream, shredders (Hyalella sp.) and collectors (Simulium sp.) were found during all stages, whereas the predator Oxelytrum discicolle was found exclusively during the floating stages, during which body temperature increased in a fashion similar to active decay in terrestrial environments.     

Determination of Coleoptera fauna on carcasses in Ankara province,Turkey

In this study, 40 species from Staphylinidae, Histeridae, Dermestidae, Silphidae, Nitidulidae and Cleridae families of Coleoptera which were found in 12 pig (Sus scrofa L.) carcasses were identified and recorded during a one-year period at the Hacettepe University Beytepe Campus located in Ankara, Turkey. According to the duration of their presence on the carcasses, 22 of these species were accepted to be important in decomposition. Their distribution over the months and the duration of their presence in the various decomposition stages over the seasons were determined.     

NCBI数据库在常见嗜尸性蝇类种属鉴别中的应用

目的探讨NCBI数据库比对分析对常见嗜尸性蝇类种属鉴别中的应用价值。方法收集2009年1月至2012年12月重庆市常见嗜尸性蝇类不同发育历期2科5属7种样本52份,采用Chelexl00法提取mtDNA,利用2对引物扩增细胞色素C氧化酶辅酶I基因,分别截取498bp和841bp相同长度的序列,采用MEGA软件计算种内及种间进化分歧情况,并分别在NCBI数据库进行序列BLAST搜索种属同源性比对分析。结果所得序列种内进化分歧均数在0％～0．7％之间,种问进化分歧均数在7．5％～16．1％之间;7个种属的样本序列Ⅰ和序列Ⅱ分别有5个和6个种属完全比对正确,样本总体的正确率分别达到96．15％和98．08％,Maxident值均在97％以上。结论采用序列同源性比对分析,并借助NCBI数据库强大的检索分析功能,可准确进行常见嗜尸性蝇类的种属鉴定,为法医学死亡时间推断提供重要参考依据。     

A Preliminary Forensic Entomological Study of Beetles (Coleoptera) in Interior Alaska,USA*

Forensic entomology uses knowledge of arthropod ecology to help solve crimes. There has been no published forensic entomological research in Alaska. We used one piglet carcass split in half to create two carcass plots in Fairbanks (~64.8°N, subarctic) that were sampled over a period of 59 days in 2019. Four pitfall traps were placed around each carcass, and four similarly arranged pitfall traps were placed 40 m distant as controls. Traps were emptied approximately weekly covering the first four stages of decomposition. We focused on adults of the larger-bodied (>9 mm) families and subfamilies of Coleoptera: Staphylinidae (subfamily Staphylininae), Carabidae, and Silphidae. A total of 621 specimens were collected and processed: 29 staphylinines, 210 carabids, and 382 silphids. A one-way ANOVA showed no significant difference between the mean numbers of staphylinines or carabids caught in carcass versus control traps. Silphids showed significantly greater mean number of beetles caught in carcass traps relative to control traps. Four species of Silphidae were documented, but contrary to similar studies, the vast majority of specimens belonged to two species of Nicrophorus (N. vespilloides Herbst and N. investigator Zetterstedt). Each of the three target taxa showed a peak in the number of specimens collected during the bloat stage of decomposition despite the carabid peak being driven by a phytophagous species.     

新乡地区夏季常见嗜尸性昆虫群落演替规律初步研究

目的研究新乡地区夏季嗜尸性昆虫的种类及其群落演替规律。方法观察法研究新乡医学院动物房后偏僻草地上6只大白鼠和5只家兔尸体腐败过程中嗜尸性蝇类的主要物种及其群落演替规律。结果该地区主要出现嗜尸性蝇类为双翅目3科7种,包括家蝇、大头金蝇、丝光绿蝇、棕尾别麻蝇、黑尾黑麻蝇、厩腐蝇、元厕蝇,且呈现出演替规律性。结论研究结果可作为新乡地区对尸体死亡时间的推断依据。     

Decomposition and Arthropod Succession in Whitehorse,Yukon Territory,Canada

Forensic arthropod succession patterns are known to vary between regions. However, the northern habitats of the globe have been largely left unstudied. Three pig carcasses were studied outdoors in Whitehorse, Yukon Territory. Adult and immature insects were collected for identification and comparison. The dominant Diptera and Coleoptera species at all carcasses were Protophormia terraneovae (R‐D) (Fam: Calliphoridae) and Thanatophilus lapponicus (Herbst) (Fam: Silphidae), respectively. Rate of decomposition, patterns of Diptera and Coleoptera succession, and species dominance were shown to differ from previous studies in temperate regions, particularly as P. terraenovae showed complete dominance among blowfly species. Rate of decomposition through the first four stages was generally slow, and the last stage of decomposition was not observed at any carcass due to time constraints. It is concluded that biogeoclimatic range has a significant effect on insect presence and rate of decomposition, making it an important factor to consider when calculating a postmortem interval.     

Mitochondrial DNA cytochrome oxidase I gene: potential for distinction between immature stages of some forensically important fly species (Diptera) in western Australia

Forensic entomology requires the fast and accurate identification of insects collected from a corpse for estimation of the postmortem interval (PMI). Identification of specimens is traditionally performed using morphological features of the insect. Morphological identification may be complicated however by the numerical diversity of species and physical similarity between different species, particularly in immature stages. In this study, sequencing was performed to study the mitochondrial DNA (mtDNA) as the prospective basis of a diagnostic technique. The sequencing focused on a section of the cytochrome oxidase I encoding region of mtDNA. Three species of calliphorid (blow flies) commonly associated with corpses in western Australia, Calliphora dubia, Chrysomya rufifacies and Lucilia sericata, in addition to specimens of Calliphora augur and Chrysomya megacephala were studied. Phylogenetic analysis of data revealed grouping of species according to genus. The DNA region sequenced allowed identification of all species, providing high support for separation on congeneric species. Low levels of variation between some species of the same genus however indicate that further sequencing is required to locate a region for development of a molecular-based technique for identification.     

Impact of plastic wrapping on carcass decomposition and arthropod colonisation in northern Africa during spring

The effect of plastic wrapping on decomposition rate and carrion fauna of rabbits (Oryctolagus cuniculus L.) was examined in spring in a semi-urban area in North Algeria. All decomposition stages were observed in all carcasses, with the same durations in the control but different durations in the wrapped carcasses. Decomposition of the carcasses in the plastic wrapping was significantly slower than that of the exposed ones. A total of 12,516 specimens, belonging to 36 families and 69 species, were morphologically identified. Thirteen species of forensic relevance were also identified at the molecular level using the cytochrome c oxidase I (COI) barcode region, and the sequences were submitted to online databases. Wrapping had a significant effect on species composition (χ² = 569.269, df = 55, p < 0.001). Higher species richness, abundance, and diversity were found in the control group. No significant difference in species abundance was observed between the treatments. The plastic wrap did not influence the accessibility of carcasses to insects, nor did it delay the arrival of necrophagous flies. This study provides basic information on the decomposition and arthropod colonisation of wrapped remains and contributes to the literature on North African carrion fauna.     

利用COI序列序列鉴定常见嗜尸性蝇种

目的 检测嗜尸性蝇类线粒体DNA(mtDNA)细胞色素氧化酶辅酶Ⅰ(COI)中278bp序列,鉴定蝇科3属5种嗜尸性蝇,解决其形态学种类鉴定的难题,为死亡时间推断提供技术支持.方法 从15省、市(地区)室外草地家兔尸体上采集蝇科3属5种共计18个蝇类成蝇样本,提取mtDNA进行PCR扩增,序列测定且上传GENBANK,...     

人与动物毛发角蛋白组分的等电聚焦图谱分析

本文用聚丙烯酰胺等电聚焦(PAGIEF)对来自6个目、15个科、20种动物毛发角蛋白组分进行了研究。发现人与动物毛发角蛋白组分的PAGIEF谱型有显著差异;不同种属的动物毛发角蛋白组分的PAGIEF谱型也互不相同,它们各自都有独特的角蛋白PAGIEF谱型。作者认为,本方法可用于鉴定毛发的种属。     

DNA-based and taxonomic identification of forensically important Sarcophagidae (Diptera) in southeastern Spain

Studying dipterans at the scene of a death can provide essential information for interpreting the evidence and help to reconstruct the events happened to a corpse in the past. Molecular tools have been employed for identification at specific levels in the cases of cryptic species or poorly conserved specimens. Identification of specimens is essential in forensic entomology since each species has a specific growth rate, which determines the calculation of the minimum post mortem interval (minPMI). In addition, phylogeographic reconstruction within a species can help to differentiate the haplotypes from a geographic area, thereby helping to clarify the possible relocation of a corpse. The morphological identification of Sarcophagidae species is often difficult, especially for the females. This is an important Diptera family since some of its species are among the first to reach a corpse, especially in warm areas. In this study, we compared the sarcophagids found in human corpses in forensic cases in Alicante (southeast of Spain) with specimens collected from baited traps in the same area and surrounding provinces. In total, 189 specimens were collected, comprising 72 from forensic cases and 117 from baited traps. Molecular identification was conducted by sequencing the cox1 mitochondrial gene and analyzing the sequences using ABGD, GMYC, and BIN species delimitation methods. The median joining algorithm in the PopART program was used to construct phylogeographic networks. Eight species in the family Sarcophagidae were identified. The most widely collected species were Sarcophaga argyrostoma and Sarcophaga tibialis. The haplotype networks obtained for these species did not indicate a clear geographic distribution of haplotypes. The S. argyrostoma samples from Alcoy were clearly isolated. The results demonstrated that this method is useful for identifying Sarcophagidae samples in forensic investigations and it can be employed for minPMI estimation.     

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.     

Seasonal structure and dynamics of sarcosaprophagous fauna on pig carrion in a rural area of Cordoba (Argentina): their importance in forensic science

Four experiments, one in each season, were carried out during 2004 in a rural area of Córdoba, central Argentina. Two pigs (Sus scrofa L.), weighing approximately 8 kg each, were used in each of the four experiments. The animals were killed by a sharp blow to the head and immediately placed in an appropriate arthropod trap. One pig was placed in the shade and the other under direct sunlight. This research was conducted to determine the seasonal structure and dynamics of arthropods that constitute the sarcosaprophagous community in a given area of the central region of Argentina. The decomposition process was divided into five stages: fresh, bloated, decay, advanced decay and dry. The duration of each stage varied in different seasons, showing that the temperature and humidity are the most important variables that influence this process. A total of 51,500 adults and 36,909 immature were collected. More than 80% of the specimens collected belong to Insecta, and within this, Diptera were the most abundant order. The flies were mainly represented by adults and immature of the following species: Chrysomya albiceps (Wiedemann) (Calliphoridae), Musca domestica Linnaeus (Muscidae) and Fannia femoralis (Stein) (Fanniidae). Coleoptera were mainly represented by adults and immature of the species Creophilus maxillosus (Linnaeus) (Staphylinidae) and Dermestes maculatus (Geer) (Dermestidae). More than 50% of hymenopteran fauna collected belong to Formicidae. The trophic levels associated with the decomposition of the remains included five categories: necrophagous, parasites and predators of the necrophagous species, omnivores, opportunists and adventives. During faunal succession a strong dominance of the necrophagous species of the family Calliphoridae and Muscidae was observed, mainly during the early stages of decay process in all seasons.     

Determination of drug levels in two species of necrophagous Coleoptera reared on substrates containing morphine

Two species of necrophagous Coleoptera: Dermestes frischi (Dermestidae) and Thanatophilus sinuatus (Silphidae), were reared on substrates containing different amounts of morphine. Colonies of D. frischi were reared on rabbit carcasses which had been given 10, 20, and 40 mg/h of morphine hydrochloride via ear artery perfusion over a 3 h period prior to death. A fourth rabbit served as a control. T. sinuatus was reared on minced beef spiked with morphine hydrochloride to give concentrations of 1,000, 2,500, 5,000, and 10,000 ng/g and one control colony. These dosages were calculated to create tissue concentrations of morphine similar to those encountered in human deaths due to morphine overdose. Larvae. pupae, and adults (except for T. sinuatus) were analyzed for morphine content. All developmental stages of D. frischi were positive for morphine and concentrations correlated with cadaveric tissue concentrations during larval stages and to a lesser extent in the adult stage. For T. sinuatus, the best correlations were found in 2nd and 3rd instar larvae. This study demonstrates the potential for use of necrophagous Coleoptera, as well as Diptera larvae, as alternate specimens for toxicological analyses.     

Determination of postmortem interval by arthropod succession: a case study from the Hawaiian Islands

A postmortem interval of 34 to 36 days was established for remains recovered on the island of Oahu, Hawaii, based on interpretations of patterns of arthropod succession on the remains. This interval was primarily based on the presence of adult specimens of Philonthus longicornis (family Staphylinidae), mature larvae of Piophila casei (family Piophilidae), and empty puparial cases of Chrysomya rufifacies (family Calliphoridae). Species and developmental stages of two additional Coleoptera species and three additional Diptera species were also present, which was consistent with the estimated interval, although not definitive.