Precise identification of insect species and their developmental stages (instars) on human remains is crucial for estimating the postmortem interval (PMI) and detecting potential body tampering. However, larvae of many common species can only be reliably identified using molecular techniques, which are not always possible. Furthermore, determining the instar stage is even more challenging, as features necessary for precise identification are often poorly documented. Oiceoptoma thoracicum (Linnaeus, 1758) is a common necrophagous beetle in the Palearctic region from the Western Europe to Japan. The species is also frequently found on cadavers of large vertebrates, including human remains, making it a promising candidate for use as a bioindicator in forensic entomology. Adults can be easily distinguished from other species; however, larvae have never been thoroughly described. The identification of O. thoracicum based on immature stages, or the differentiation of instars of this species is therefore not yet possible. The aim of this study was to provide reliable morphological characters that would allow the identification of larvae and instar stages in O. thoracicum. Quantitative and qualitative morphological characters for instar and species identification are described and illustrated. A list of described immature stages of the genus Oiceoptoma is provided.

• Klíčová slova
• Carrion beetles, forensic entomology, immature stages, larval instar identification, necrophagous beetles,
• MeSH
• brouci * anatomie a histologie   růst a vývoj   klasifikace   MeSH
• forenzní entomologie MeSH
• larva anatomie a histologie   růst a vývoj   klasifikace   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.

• Klíčová slova
• Silphinae, behavior, food choice, forensic entomology, necrophagy,
• MeSH
• brouci * fyziologie   MeSH
• forenzní entomologie metody   MeSH
• larva * fyziologie   růst a vývoj   MeSH
• potravní řetězec MeSH
• preference v jídle MeSH
• stravovací zvyklosti MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

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.

• Klíčová slova
• Necrodes littoralis, fixative, morphology, preservative, storage,
• 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
• Názvy látek
• DNA * MeSH

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.

• Klíčová slova
• Necrophagous, development time, forensic entomology, larval instar, mortality, nutritional,
• 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

Coleoptera are currently considered a fundamental tool to help solve criminal investigations, allowing forensic entomologists to estimate post-mortem intervals and obtain other ecology-related information. Thanatophilus rugosus (Linnaeus, 1758) is an important necrophagous beetle distributed through most of the Palaearctic region, where it is readily found on human bodies and animal carcasses. In this study, the new thermal summation models for all the developmental stages of Thanatophilus rugosus are provided. Beetles were reared at six different constant and ecologically relevant temperatures (12, 14, 16, 18, 20, and 22 °C), and their developmental times were measured. Thermal summation constants were calculated for each developmental stage (egg, three larval instars, post-feeding stage, and pupa).

• MeSH
• brouci růst a vývoj   MeSH
• forenzní entomologie metody   MeSH
• stravovací zvyklosti MeSH
• teplota MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

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.

• Klíčová slova
• Insects, criminalistics, forensic entomology, forensic medicine, post mortem interval,
• MeSH
• ekosystém MeSH
• forenzní entomologie * MeSH
• lidé MeSH
• posmrtné změny MeSH
• soudní lékařství MeSH
• soudní vědy MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články 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.

• Klíčová slova
• Silphinae, developmental biology, forensic entomology, thermal summations model,
• 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

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.

• Klíčová slova
• Silphinae, developmental rate, forensic entomology, sexual dimorphism, thermal summation model,
• 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

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.

• Klíčová slova
• Silphidae, food choice, forensic entomology, gender, necrophagy,
• 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

Insect pupae sampled at a death scene may be used to estimate the post-mortem interval. The pupal age is however difficult to estimate, as there are no good quantitative markers for the age of a pupa. We present a novel method for pupal age estimation based on the quantification of contrast in intensity between the eyes of a pupa and the middle grey photography card as a standard background. The intensity is measured on a standardized scale from 0 (perfect black) to 255 (perfect white) using computer graphical software and pictures of the eye and the background taken with a stereomicroscope. Eye-background contrast is calculated by subtracting the average intensity of the eye from the average intensity of the background. The method was developed and validated using pupae of Necrodes littoralis (Linnaeus, 1758) (Coleoptera: Silphidae), one of the most abundant beetle species on human cadavers in Central Europe. To develop the model, pupae were reared in 17, 20 and 23 °C, with a total of 120 specimens. The method was validated by three raters, using in total 182 pupae reared in 15, 17, 20, 23 and 25 °C. We found a gradual increase in eye-background contrast with pupal age. Changes followed generalized logistic function, with almost perfect fit of the model. Using our method pupal age was estimated with the average error of 8.1 accumulated degree-days (ADD). The largest error was 27.8 ADD and 95% of age estimates had errors smaller than 20 ADD. While using the method, different raters attained similar accuracy. In conclusion, we have demonstrated that eye-background contrast is a good quantitative marker for the age of N. littoralis pupae. Contrast measurements gave accurate estimates for pupal age. Our method is thus proven to be a candidate for a reliable approach to age insect pupae in forensic entomology.

• MeSH
• barva MeSH
• brouci fyziologie   MeSH
• forenzní entomologie metody   MeSH
• kukla fyziologie   MeSH
• mikroskopie MeSH
• pigmentace MeSH
• počítačová grafika MeSH
• reprodukovatelnost výsledků MeSH
• software MeSH
• teplota MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH