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1.
    
Previous studies on Diptera have shown the potential for the use of cuticular hydrocarbons' analysis in the determination of larval age and hence the postmortem interval (PMI) for an associated cadaver. In this work, hydrocarbon compounds, extracted daily until pupation from the cuticle of the blowfly Lucilia sericata (Diptera: Calliphoridae), have been analyzed using gas chromatography–mass spectrometry (GC–MS). The results show distinguishing features within the hydrocarbon profile over the period of the larvae life cycle, with significant chemical changes occurring from the younger larvae to the postfeeding larvae. Further interpretation of the chromatograms using principal component analysis revealed a strong correlation between the magnitudes of particular principal components and time. This outcome suggests that, under the conditions of this study, the cuticular hydrocarbons evolve in a systematic fashion with time, thus supporting the potential for GC–MS analysis as a tool for establishing PMI where such a species is present.  相似文献   

2.
    
Nonbiting midges (Diptera, Chironomidae) are the most abundant members of the fauna associated with submerged carcasses, but their use in the medicolegal context is very restricted because of their complex ontogeny. In this case, the corpse of a woman was recovered in late spring from a river in Granada (Iberian Peninsula). It showed obvious signs of long permanence in the aquatic environment and, along with pulmonary and microscopical analyses, led to the conclusion that the cause of death was drowning. Several larvae‐like specimens were sampled from the scalp and later identified by morphological external features as IV instar larvae of Chironomus riparius Meigen, 1804 (Diptera, Chironomidae). Sequencing of cytochrome oxidase subunit I was performed to confirm the identification. The knowledge of the biology of C. riparius at low temperatures was critical to assess a postsubmersion interval of 16–17 days.  相似文献   

3.
Abstract: This study was conducted from March 2006 to 2007. The aim of the study was to determine the forensically significant Calliphoridae (Diptera) species and their seasonal distribution in Ankara province at Beytepe Campus. Pig carcasses were killed by a veterinary using pentobarbital sodium with intervals from 2 to 3 weeks to a month. Samples were collected from the carcass everyday in the morning, in the afternoon, and at sunset. Temperature and parameters of weather, such as cloudy, sunny, rainy, and snowy, were recorded at each visit. Phaenicia sericata (Meigen), Chrysomya albiceps (Wiedemann), Calliphora vomitoria (Linnaeus), and Calliphora vicina (Robineau‐Desvoidy) species, which belong to Calliphoridae family, were collected. It was shown that the seasonal distribution of the collected species was different from each other. The species were determined on carcass between the following times; P. sericata, from April to November; C. albiceps, from May to November; Ca. vomitoria, from February to June and from September to December; and Ca. vicina, from February to May and in June and September. Calliphoridae fauna and its annual seasonal distribution in Turkey on 12 pig carcasses were reported for the first time in this study.  相似文献   

4.
    
This study investigated the potential effects of flunitrazepam (known as “date rape drug”) on the developmental cycle of Chrysomya megacephala, an important forensic species, and their possible implications for the calculation of the PMI. A 1050 C. megacephala eggs were divided into five groups with seven replications each. The eggs were placed on artificial diet prepared with four drug concentrations of flunitrazepam (4, 8, 16, and 32 ng/g), besides the control group (prepared with water). Were evaluated the potential effects on development time, weight gain, and mortality during the cycles. The drug had no significant effect on development time or mortality although it did affect the weight of the pupae and adults (Kruskal–Wallis, p < 0.05). The result can be deduced that the determination of the postmortem interval is not affected.  相似文献   

5.
    
This study investigated the influence of paraquat, a prevalent poison used by suicides, on initial oviposition and development of Chrysomya megacephala (Fabricius) using minced‐beef substrates. Paraquat in lethal dose for human (40 mg/kg), two times the lethal dose (80 mg/kg) and five times the lethal dose (200 mg/kg) were mixed thoroughly with respective minced‐beef substrates (1 kg each) that were decomposed in a shaded habitat fully protected from rain. Results of four replications of the above experiment revealed that the presence of paraquat neither delayed initial oviposition nor prolonged the developmental stages of C. megacephala. Therefore, estimation of postmortem interval (PMI) based on empirical baseline data obtained using animal models devoid of any poisons would still be appropriate for estimating PMI in paraquat‐related deaths.  相似文献   

6.
    
This study investigates the pupal development times of the blow fly Calliphora vicina, which were studied in the laboratory at six different constant temperatures (15, 20, 23, 25, 28, and 30°C each ± 1°C). Lower thresholds (tL) for development were estimated from the linear regression of the developmental rates on each temperature. These data have made it possible to calculate the accumulated degree days (ADD) necessary for C. vicina to complete the larval stage and to achieve adult emergence. The minimal duration of development from oviposition to adult emergence was found to be inversely related to temperature. Additionally, six landmarks in pupal development are showed, and for each of the landmarks, the ADD value was calculated for every rearing temperature involved. These data assist in calculating the duration of the pupal stage based on morphological characteristics and would be of great value for future forensic entomological casework.  相似文献   

7.
我国法医昆虫学的研究进展   总被引：1，自引：0，他引：1  
Lan LM  Liao ZG  Chen YQ  Yao Y  Li JB  Li MY  Cai JF 《法医学杂志》2006,22(6):448-450
法医昆虫学是应用昆虫学知识解决有关法律问题的法医学分支学科。在推断死亡时间等方面具有明显优势。本文在阐述法医昆虫学定义和研究内容基础上,综述尸体上的昆虫生态群落演替现象、昆虫发育形态学、DNA分析技术的应用、法医昆虫毒理学等法医昆虫学问题在我国的研究进展。  相似文献   

8.
法医昆虫学(Forensic entomology)指的是应用昆虫学知识解决法律上问题的法医学分支学科,在死后间隔时间判断,特别是腐败尸体的死后间隔时间判断等方面有著无可比拟的优越性。本文讨论了法医昆虫学的研究领域,从理论研究与实践应用两方面概述了近十年来法医昆虫学在我国的进展。  相似文献   

9.
    
Nocturnal flight of blow flies (Diptera: Calliphoridae) is a controversial issue in forensic entomology. We performed two field experiments to investigate the diurnal and nocturnal activity of six blow fly species in a rainforest fragment in Brazil. Initially, nocturnal (17:30–05:30) versus diurnal (05:30–17:30) flight activity was investigated. Only 3.9% of adults were collected at night, mostly the native species Mesembrinella bicolor, and nocturnal oviposition did not occur. In the second experiment, collection of adults took place at the following intervals: 05:30–08:30, 08:30–11:30, 11:30–14:30, and 14:30–17:30. The proportions of adults did not differ significantly among the four diurnal intervals, except for Hemilucilia segmentaria, which was captured more frequently in the early morning. Calliphoridae has predominantly diurnal behavior, not laying eggs in darkness. The association of the native species M. bicolor, Hemilucilia semidiaphana, and H. segmentaria to forested areas reinforces the forensic relevance of data on their flight pattern.  相似文献   

10.
    
Insects have an important role in minimum postmortem interval (PMImin) estimation. An accurate PMImin estimation relies on a comprehensive study of the development and succession of local carrion insects. No published research on carrion insect succession exists for tropical north Queensland. To address this, we aimed to obtain preliminary observational data concerning the rate of decomposition and insect succession on pig carcasses in Townsville and compare these with other regions of Australia and overseas. Adult insects were collected daily from three pig carcasses for 30 d during summer and identified to family level. Observations of decomposition rate were made each day and progression through the stages of decomposition were recorded. Adult insects were identified to family and their presence/absence used as a proxy for arrival at/departure from the remains, respectively. These preliminary data highlight several interesting trends that may be informative for forensic PMImin estimation. Decomposition was rapid: all carcasses were at the dry/remains stage by Day 5, which was substantially quicker than all other regions in the comparison. Differences were also observed in the presence/absence of insect families and their arrival and departure times. Given the rapid progression through early decomposition, we argue that later-arriving coleopteran taxa may be more forensically informative in tropical Australia, in contrast with temperate regions where Diptera appear most useful. This research contributes preliminary observational data to understanding insect succession patterns in tropical Australia and demonstrates the critical need for comprehensive local succession data for each climatic region of Australia to enable accurate PMImin estimation. These data will inform future research targeted at gaining a more comprehensive understanding of insect succession in the Australian tropics.

Key points:

  • We obtained preliminary observational data concerning the rate of decomposition and insect succession on pig carcasses in tropical Australia.
  • Decomposition was rapid: all carcasses were at the dry/remains stage by Day 5.
  • Coleopteran taxa may be more forensically informative in tropical Australia than dipterans.
  相似文献   

11.
Abstract: Time between death and discovery of remains, or postmortem interval (PMI), can be assessed using blow fly maggot age. Forensic entomologists rely on published, often nonlocal, species‐specific developmental tables to determine maggot age. In a series of common garden experiments, we investigated the developmental rate variation between populations of Lucilia sericata collected from Sacramento, CA, San Diego, CA, and Easton, MA at 16°C, 26°C, and 36°C. For the 16°C trial the time measurement started at egg hatch, while for the higher temperatures the experiment began at oviposition; the wandering stage signified the endpoint for all experiments. The distribution of developmental times differed significantly (ANOVA, p < 0.001) between the three populations within each temperature treatment. We discovered that regional variation of developmental times within a blow fly species exists. This study demonstrates the importance of assembling local population‐specific developmental tables when estimating larval age to determine PMI.  相似文献   

12.
    
This case report describes an incident of myiasis in Oklahoma City, Oklahoma. Paramedics treated a 53‐year‐old man in the field when he suffered cardiac arrest. He was intubated by the paramedics and transported to an emergency room, where he received two stents and a balloon pump. He was found to have a GCS of three and remained in the hospital for 7 days before passing away. After his death, the breathing tube was removed, revealing the presence of several maggots. On closer inspection, the dipteran larvae were found in both the oral and nasal cavities. Four of these larvae were reared to adulthood and identified as Lucilia cuprina (Weidemann) (Diptera: Calliphoridae), commonly known as the Australian sheep blowfly, by the Biology Department of the University of Oklahoma. Based on the fly's life cycle and rate of development, the infestation is suspected to be hospital acquired.  相似文献   

13.
    
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.  相似文献   

14.
    
The characteristic life stages of infesting blowflies (Calliphoridae) such as Chrysomya megacephala (Fabricius) are powerful evidence for estimating the death time of a corpse, but an established reference of developmental times for local blowfly species is required. We determined the developmental rates of C. megacephala from southwest China at seven constant temperatures (16–34°C). Isomegalen and isomorphen diagrams were constructed based on the larval length and time for each developmental event (first ecdysis, second ecdysis, wandering, pupariation, and eclosion), at each temperature. A thermal summation model was constructed by estimating the developmental threshold temperature D0 and the thermal summation constant K. The thermal summation model indicated that, for complete development from egg hatching to eclosion, D0 = 9.07 ± 0.54°C and K = 3991.07 ± 187.26 h °C. This reference can increase the accuracy of estimations of postmortem intervals in China by predicting the growth of C. megacephala.  相似文献   

15.
    
This study investigated effects of ketamine on the development of Chrysomya Megacephala (Diptera: Calliphoridae) at three different temperatures. Larvae of the C. Megacephala were exposed to different concentrations of drugs and temperatures. The larval lengths, weights, and developmental durations of each stage were observed. This study demonstrated that ketamine, low temperature, and their synergistic action significantly suppressed the development of C. Megacephala (p < 0.001). The time that the larvae in all the treatments achieved the maximum length/weight was significantly delayed (p < 0.05), and that resulted in prolonged duration of larval and prepupal stages especially at low temperature. However, no linear correlations were discovered between ketamine concentration and growth rate of larval length/weight.  相似文献   

16.
法医昆虫学是应用昆虫学知识解决法医实践中所遇到的相关问题的一门科学。食尸性蝇类在尸体的腐败分解中发挥着重要的作用,运用食尸性蝇类的特点可以更准确进行死亡时间推断,为侦查破案提供线索。本文对依据食尸性蝇类推断死亡时间的方法进行综述,以期为后续的研究与实践应用参考和借鉴。  相似文献   

17.
Wang BQ  Cai JF  Ge Y  Li FZ  Man Y  Chang YF 《法医学杂志》2008,24(3):210-213
尸源性昆虫学是应用昆虫学知识解决有关法律问题的法医学分支学科,对死亡时间的推断。特别是腐败尸体的死后间隔时间的推断等方面具有无可比拟的优越性。本文根据国内外近期法医昆虫学方面的研究进展,阐述了尸源性昆虫的研究历史、种类和侵蚀过程,并总结了尸源性昆虫形态学及分子生物学的种属鉴定方法。及近几年来在推断死亡时间方面的具体应用。就尸源性昆虫在法医学领域内的应用及进展进行综述。  相似文献   

18.
基于昆虫的死亡时间推断是目前最为有效和最准确的方法,本文介绍了广东省4例应用昆虫准确判断死亡时间的案例,这些案例分别发生于3月、5月和6月,现场包括室外现场和室内现场,尸体类型包括死亡不久的尸体和高度腐败的尸体,死亡原因包括钝器窒息、锐器致死、勒颈致死及过量药物中毒致死,其中过量药物中毒致死的案例由于体内含有49倍致死剂量的氯氮平从而使昆虫的发育受到严重影响进一步使得死亡时间推断时间结果比真实时间短。  相似文献   

19.
    
Postfeeding dispersal involves migration of larvae away from their food source in order to pupate. Puparia are difficult to find, yet are important for estimating PMI, and missing puparia during collection can result in inaccurate estimations. This study investigates the late season maggot dispersal patterns for blow flies at coyote carcasses in two habitats with an aim to improving puparia collection procedures. Puparia samples collected from various dispersal distances and directions tested the spatial distribution patterns of the various species using the variance/mean ratio (VMR). Lucilia illustris was the most common species to emerge, with a preferred minimum dispersal distance of more than 50.8 cm and an overall VMR value of 14.91, indicating this species had a clumped distribution pattern. These findings highlight that current collection procedures that use random sampling from under carcasses do not adequately account for the spatial distribution of larvae.  相似文献   

20.
Abstract: Larvae and pupae of blow fly species are frequently used in postmortem interval estimation, their age indicating minimum time since death. Most studies have considered age estimation of larvae, neglecting study of pupae. Relative development of external pupal features is useful, but there are also internal changes during metamorphosis that may be indicators of age, utilizing histological techniques. This study aimed to optimize preservation and histological analysis of blow fly pupae, specifically Calliphora vicina Robineau‐Desvoidy and Lucilia sericata (Meigen), and to examine internal features with potential for age estimation. Effect of hot‐water‐killing and different preservatives were examined. It was determined that blow fly pupae should be pierced through the three tagma, hot‐water‐killed, and preserved in 80% ethanol as the optimal preservation for subsequent analyses. Hematoxylin and eosin stained pupal sections revealed differences in brain and thoracic muscle development throughout the pupal stage with potential for age estimation.  相似文献   

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