Proper fixing and long-term preservation of entomological evidence are essential in collections and research and crucial in applied fields such as forensic entomology. Incorrectly stored samples may lose important morphological features over time, rendering molecular analyses exceedingly difficult. The most effective method for preserving soft samples such as larvae is fluid preservation. It uses a combination of a wide range of fixatives and storage fluids. However, very little comparative work has been done to determine the effects of long-term storage on sample quality in terms of color, shape, and DNA stability. Moreover, the current golden standard in forensic entomology has been tailored for age estimation of larvae of Diptera, which differ from larvae of Coleoptera in morphology and subsequently in applied methods. We compared the effects of combinations of 6 commonly used fixatives and 6 commonly used storage fluids on midsized larvae of the forensically important beetle, Necrodes littoralis (Linnaeus, 1758), in terms of color, shape, and suitability for DNA analyses over a 2-yr period. We were looking for combinations that can preserve specimens in a satisfactory state, can be used on a regular basis, do not require advanced protection or skills of the personnel, and are not toxic or too harmful to the environment. We found not only several methods that scored significantly better in the tested parameters compared with the golden standard but also several common methods that should be avoided. The effects of agents on each tested category are discussed in detail.
- MeSH
- barva MeSH
- brouci * MeSH
- časové faktory MeSH
- DNA * analýza MeSH
- forenzní entomologie metody MeSH
- larva * růst a vývoj MeSH
- ochrana biologická metody MeSH
- odběr biologického vzorku metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie 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.
This study examined the effects of various diets on the development time and survival of the carrion beetle Thanatophilus rugosus (Fabricius, 1775). We attempted to find the best diet for rearing the species in laboratory conditions for entomological research and forensic purposes, and to further understand its feeding habits. The larval stages were monitored while feeding on three types of meat under a constant temperature. We discovered that the shortest development time in total was achieved in larvae fed with pork liver, followed closely by pork muscle. The longest development and lowest survival rates were observed when introducing a chicken diet. We were also able to identify specific stages during which the diet significantly affected the development.
- MeSH
- brouci růst a vývoj MeSH
- dieta MeSH
- entomologie MeSH
- forenzní entomologie MeSH
- larva růst a vývoj MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Entomológia sa zaoberá skúmaním hmyzu ako súčasti ekosystému úzko spätého so všetkými organizmami, človeka nevynímajúc. Hmyz je často „priamym svedkom“ kriminálneho činu a tým pádom významným dôkazom pri vyšetrovaní zahŕňajúcom aj špecializovaný odbor - forenzná entomológia. Jej cieľom je komplexná analýza hmyzu pre účely vyšetrovania aj v oblasti kriminalistiky a súdneho lekárstva. Závery skúmania sú zdrojom informácii, vedúcich k zodpovedaniu otázok najmä v prípadoch závažných trestných činov.
ntomology, as a vast scientific discipline of zoology, deals with the study of insects, which are an integral part of the ecosystem of our planet and are closely linked to the activity and life cycle of all organisms, including humans. As a result of this natural connection, insects often become a direct “living witness” of a crime and thus an invaluable part of the evidence in a comprehensive forensic investigation, which in such cases necessarily includes a specialized field of science - forensic entomology. The goals of forensic entomology include comprehensive analysis of entomological evidence material and the use of knowledge about insects and other invertebrates for the purpose of investigating and verifying evidence in civil and criminal law. In practice, forensic entomology falls into several categories, including the issue of food pests in industry or agriculture, human and animal parasitology (especially myiasis) and very often the field of criminology and forensic medicine, where the results are mainly applied to determine the length of post mortem interval (PMI), evidence of manipulation of the corpse, or other forensic facts that results from entomological analysis. The conclusions of the entomology study are in many cases an invaluable part of the amount of information that leads to the answer of key questions in complex forensic evidence, especially in the group of serious crimes.
- MeSH
- forenzní entomologie * MeSH
- lidé MeSH
- posmrtné změny MeSH
- soudní lékařství MeSH
- soudní vědy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy 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
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
The postmortem interval (PMI) estimation, in cases where the body was discovered in an advanced stage of decomposition, is predominantly based on entomological evidence. However, very few forensically important species are sufficiently known in detail to allow a practical application. One of them is the carrion beetle, Necrophila (Calosilpha) brunnicollis (Kraatz, 1877). Its development from egg to adulthood was studied under a range of ecologically relevant constant temperatures to find parameters of thermal summation models. Developmental sexual dimorphism and the presence of developmental rate isomorphy were investigated. Herein we present the lower developmental thresholds and sum of effective temperatures for all developmental stages of N. brunnicollis (egg, first-third larval instar, postfeeding stage, and pupae). We did not find any evidence of developmental sexual dimorphism nor was the presence of developmental rate isomorphy confirmed. Our results present the first thermal summation model of the East Asian carrion beetle that can be used for the PMI estimation.
- MeSH
- brouci růst a vývoj MeSH
- forenzní entomologie metody MeSH
- kukla růst a vývoj MeSH
- larva růst a vývoj MeSH
- mrtvola MeSH
- posmrtné změny MeSH
- sexuální faktory MeSH
- teoretické modely MeSH
- teplota MeSH
- zvířata MeSH
- zvláštnosti životní historie MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Necrophagous beetles of genus Thanatophilus are well recognized as a group of beetles with a high potential utility in forensic entomology. They can be used to estimate postmortem interval (PMI) or validate the value for other groups of insects commonly encountered on human remains, like blowflies (Calliphoridae). However, reliable tools for instar and species identification of their larvae are needed as such information is crucial for allowing accurate PMI estimate. One of the most common species of the genus Thanatophilus in Europe is Thanatophilus sinuatus. This species occurs frequently on human remains and its larvae feed on decaying tissues throughout their development. Therefore, the larvae could become useful bioindicators for forensic entomology, although their current description does not allow reliable instar or species identification. Our goal was to provide morphological characters for species and instar identification of all larval stages of T. sinuatus. The larvae were obtained from laboratory rearing under controlled conditions (20 °C and 16:8 h of light/dark period). Qualitative and quantitative morphological instar and species-specific characters are described and illustrated. Additionally, we report observations of biological and developmental lengths for all stages of the species. We also compared these morphological characters with recent description of T. rugosus and provided an identification key of these two similar and often co-occurring species. We noticed that some characters for instar identification were shared between T. sinuatus and T. rugosus and were confirmed by comparison with larvae of T. dentigerus that they can be applied to other species of the genus.
- MeSH
- brouci klasifikace růst a vývoj MeSH
- forenzní entomologie * MeSH
- hodnotící studie jako téma MeSH
- kukla klasifikace růst a vývoj MeSH
- larva klasifikace růst a vývoj MeSH
- mikroskopie elektronová rastrovací MeSH
- optické zobrazování MeSH
- stravovací zvyklosti MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
