Necrophagous
Dotaz
Zobrazit nápovědu
BACKGROUND: Recently, the World Health Organization launched a campaign to eradicate the tropical disease yaws, caused by the bacterium Treponema pallidum subsp. pertenue; however, for decades researchers have questioned whether flies act as a vector for the pathogen that could facilitate transmission. METHODS: A total of 207 fly specimens were trapped in areas of Africa in which T. pallidum-induced skin ulcerations are common in wild baboons; 88 flies from Tarangire National Park and 119 from Lake Manyara National Park in Tanzania were analyzed by PCR for the presence of T. pallidum DNA. FINDINGS: We report that in the two study areas, T. pallidum DNA was found in 17-24% of wild-caught flies of the order Diptera. Treponemal DNA sequences obtained from many of the flies match sequences derived from nearby baboon T. pallidum strains, and one of the fly species with an especially high prevalence of T. pallidum DNA, Musca sorbens, has previously been shown to transmit yaws in an experimental setting. INTERPRETATION: Our results raise the possibility that flies play a role in yaws transmission; further research is warranted, given how important understanding transmission is for the eradication of this disfiguring disease.
- MeSH
- bakteriální geny MeSH
- Diptera klasifikace mikrobiologie MeSH
- DNA bakterií * MeSH
- ekosystém * MeSH
- fylogeneze MeSH
- hmyz - vektory mikrobiologie MeSH
- mikrobiologie životního prostředí MeSH
- Papio mikrobiologie MeSH
- sekvenční analýza DNA MeSH
- Treponema genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Afrika MeSH
- Tanzanie MeSH
The thermoregulation behavior of Lucilia sericata larvae (Diptera: Calliphoridae), a necrophagous species that feeds on vertebrate cadavers, was investigated. These larvae require high heat incomes to develop, and can elevate temperatures by forming large aggregates. We hypothesized that L. sericata larvae should continue to feed at temperatures up to 38 °C, which can be reached inside larval masses. Thermal regulation behavior such as movement between a hot food spot and colder areas was also postulated. The hypotheses were tested by tracking for 1 h the activity of single, starved third instar larvae in a Petri dish containing 1 food spot (FS) that was heated to a constant temperature of 25 °C, 34 °C or 38 °C with an ambient temperature of 25 °C. The influence of previous conspecific activity in the food on larval behavior was also tested. The crops of larvae were dissected to monitor food content in the digestive systems. Based on relative crop measurements, larvae fed at all food temperatures, but temperature strongly affected larval behavior and kinematics. The total time spent by larvae in FS and the duration of each stay decreased at high FS temperature. Previous activity of conspecifics in the food slightly increased the time spent by larvae in FS and also decreased the average distance to FS. Therefore, necrophagous L. sericata larvae likely thermoregulate during normal feeding activities by adjusting to local fluctuations in temperature, particularly inside maggot masses. By maintaining a steady internal body temperature, larvae likely reduce their development time.
- MeSH
- Diptera růst a vývoj fyziologie MeSH
- larva růst a vývoj fyziologie MeSH
- stravovací zvyklosti MeSH
- termoregulace * MeSH
- vysoká teplota MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
To accurately model the food webs, we need to acquire precise data on food ecology of the interacting species. This allows better understanding of the trophic interactions and for the necrophagous species this information could be used in medico-legal investigations. For this reason, we recently proposed standardized laboratory methodology to assess the foraging strategies based on parallel testing of 2 food items (meat, dead larvae) (Jakubec et al. 2021). The original methodology had 2 shortcomings. It was not suited for testing living larvae, which could prove predatory behavior of the species. The methodology was also based on parallel experimental design, where the food items are tested together, which could underestimate the maximum consumption of the tested subject for some items. To test if these concerns are valid, we improved original methodology allowing testing living larvae as well as a new sequential experimental setup, where consumption of each item is tested individually in a random order, thus theoretically giving an unbiased maximum consumption estimate. These methodologies were tested head-to-head on 3 forensically relevant species from the genus Thanatophilus (Thanatophilus micans (Fabricius 1794)(Fabricius 1794), Thanatophilus rugosus (Linnaeus, 1758), and Thanatophilus sinuatus(Fabricius, 1775)). The experiments have confirmed that all 3 species are almost strictly necrophagous, although they were capable of predation, despite the presence of preferred food (meat). The comparison also showed that the sequential design has indeed improved capability to quantify the maximal consumption of the given food item. Thus, we suggest following this methodology in future studies.
Necrophagous blowflies (Diptera: Calliphoridae) are of great importance particularly during investigations of suspicious deaths. Many studies have analyzed the distribution of blowflies based on pig experiments and baited trapping; however, data from real case scenarios are rarely used. In this article, the distribution of blowflies found during investigations of 160 real cases during 1993-2007 in Switzerland is evaluated based on habitat, altitude, and season. Ten species of blowflies were present in 145 out of the 160 cases. The most common species was Calliphora vicina, which occurs throughout the year and was present in 69 % of all cases. Lucilia sericata, Calliphora vomitoria, and L. caesar were identified among the rest of the flies as species of great forensic importance mainly due to their distributional patterns. After a comparison with a similar dataset from Frankfurt, Germany, some surprising differences were determined and discussed. The biggest discrepancies between our dataset and the German dataset were in the occurrences of L. sericata (30 % vs. 86 %, respectively), Phormia regina (5 % vs. 43 %), and L. ampullacea (1 % vs. 45 %). The life-history strategies and intraspecific behavioral variability of blowflies remain understudied, although they can be essential for an unbiased approach during a death investigation. Further research and comparison of occurrence patterns across the area of distribution of blowflies are therefore needed and recommended.
Precise data regarding feeding habits of necrobiont species are a key element of food web and evolutionary ecology. They can also be used to assess the utility and value of those species for forensic entomology, where obligatory necrophagous species in particular are considered good bioindicators of postmortem or preappearance interval. However, the feeding habits of many species are known only from anecdotal field observations, often reduced to vaguely defined categories-predatory, necrophagous, or omnivorous. To address this issue, we designed a simple, in vitro behavioral experiment allowing the quantification of food preferences. Next, we applied it on Necrophila (Calosilpha) brunnicollis (Kraatz, 1877), which is a common carrion beetle of East Asia with unresolved food preferences. The results suggest that this species is preferentially necrophagous, thus valuable for forensic research. Importantly, however, our experimental design allowed us to reveal that it also readily feeds on larvae of Diptera, although they compose a minor proportion of its diet. This methodology can be applied to other species, and it could provide evidence for future decision making in forensic research.
- MeSH
- brouci * MeSH
- forenzní entomologie metody MeSH
- mrtvola MeSH
- posmrtné změny MeSH
- stravovací zvyklosti * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Kazuistické sdělení demonstruje spolupráci odborníků soudního lékařství a forenzní entomologie při využití hmyzu při stanovení post mortem intervalu. Současně prezentuje méně častý důsledek působení nekrofauny na stav mrtvého, se kterým se v České republice zpravidla setkáváme pouze u mrtvol dlouze exponovaných v uzavřených prostorách.
The case report illustrates a cooperation of the specialists in forensic medicine and forensic entomology using insect in estimation of the post mortem interval. It simultaneously presents less frequent consequence of the necrophagous fauna effect on the dead body condition, generally encountered in the Czech Republic only on corpses exposed for a long time in enclosed spaces.
- Klíčová slova
- doba od smrti, forenzní lékařství, výměty hmyzích larev (frass),
- MeSH
- brouci MeSH
- časové faktory MeSH
- Diptera MeSH
- entomologie metody MeSH
- hmyz * MeSH
- lidé MeSH
- mrtvola * MeSH
- pitva MeSH
- posmrtné změny MeSH
- roční období MeSH
- senioři MeSH
- smrt MeSH
- soudní lékařství MeSH
- soudní vědy * MeSH
- stadia vývoje MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- kazuistiky MeSH
Necrophagous Diptera are the most important group of insects used for the purposes of forensic entomology. While the most utilized fly family in this context is the family Calliphoridae, there are several other families that can be of great importance during real-case investigations. This article analyzes the necrophagous flies of all families recorded from 160 real cases in Switzerland between 1993 and 2007. A total of 56 species belonging to 16 families was identified with Calliphoridae being the most dominant family (90.63% of all cases), followed by Muscidae (26.25%), Sarcophagidae (19.38%), Phoridae (14.38%), and Fanniidae (12.50%). For specimens that were difficult to identify morphologically, a new PCR primer has been specifically designed for the amplification of a short, informative COI barcode in degraded museum samples of forensically important Diptera taxa. The richest family in terms of species was the family Muscidae with 16 species. Fannia fuscula (Fallen) and Fannia monilis (Haliday) were recorded from human cadavers for the first time. The study highlights the importance of different fly families in forensic investigation, enhancing our comprehension of their prevalence and dispersion in real cases in Central Europe. The results pave the way for additional exploration, especially regarding the involvement of less frequently observed species in forensic entomology.
- MeSH
- Calliphoridae MeSH
- Diptera * MeSH
- entomologie MeSH
- lidé MeSH
- Muscidae * MeSH
- Sarcophagidae * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Geografické názvy
- Švýcarsko MeSH
Carrion beetles of genus Thanatophilus (Leach, 1815) are an important group of necrophagous insects, with great potential for forensic entomology in temperate zones of Africa, America, Asia, and Europe. Developmental models for majority of Thanatophilus species remain unknown. In this study, we will provide new thermal summation models for all the developmental stages of Thanatophilus sinuatus (Fabricius, 1775), one of the most abundant and widespread species of the genus. The beetles were bred at seven different constant temperatures, and developmental time was measured for each developmental stage (egg, three larval instars, postfeeding stage, and pupa). Temperature-sex influence was tested, and thermal summation constants were calculated to be used for postmortem interval estimation during criminal investigations.
- MeSH
- biologické modely MeSH
- brouci růst a vývoj MeSH
- forenzní entomologie * MeSH
- kukla růst a vývoj MeSH
- larva růst a vývoj MeSH
- ovum růst a vývoj MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We assessed the influence of diet on the development and survival in the immature stages of the necrophagous beetle Oiceoptoma thoracicum (Linnaeus, 1758). The species is frequently observed on large cadavers, including humans, and thus can be of potential forensic relevance. We compared multiple meat tissues from three animal sources, and detected the optimal diet for rearing the species for further entomological and forensic objectives. We reared 203 individuals to adulthood at the constant temperature of 20°C. Our results represent the first robust data set of the development time for this species. They further confirmed a significant relationship between survival and the type of diet, as the highest survival rates were detected in larvae fed with both pork liver and pork muscle.
Determination of insect species and their instars, occurring on human remains, is important information that allows us to use insects for estimation of postmortem interval and detect possible manipulation with the body. However, larvae of many common species can be identified only by molecular methods, which is not always possible. The instar determination is even more challenging, and qualitative characters that would allow a more precise identification are mostly unknown. Thanatophilus rugosus (Linnaeus, 1758) is a common necrophagous beetle in the whole Palaearctic region from Europe to Japan. The species is often encountered on corpses of large vertebrates including humans, and its potential to become a useful bioindicator for forensic entomology is therefore high. Adults can be easily distinguished from other species; however, larvae were never thoroughly described to allow species and instar identification. The aim of this study was to provide reliable morphological characters that would allow species and instar identification of T. rugosus larvae. The material for morphological study was obtained from rearing under controlled conditions (20 °C and 12:12 h of light/dark period), and specimens that were not studied morphologically were allowed to complete their development. Quantitative and qualitative morphological characters for instar and species identification are described and illustrated. Additionally, we report observations of biology and developmental length for all stages of the species.
- MeSH
- brouci růst a vývoj MeSH
- larva růst a vývoj MeSH
- mikroskopie elektronová rastrovací MeSH
- optické zobrazování MeSH
- soudní vědy MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
