Chrysomya albiceps (Wiedemann) and Hemilucilia segmentaria (Fabricius) (Diptera, Calliphoridae) used to estimate the postmortem interval in a forensic case in Minas Gerais, Brazil

ABSTRACT. Chrysomya albiceps (Wiedemann) and Hemilucilia segmentaria (Fabricius) (Diptera, Calliphoridae) used to estimate the postmortem interval in a forensic case in Minas Gerais, Brazil. The corpse of a man was found in a Brazilian highland savanna (cerrado) in the state of Minas Gerais. Fly larvae were collected at the crime scene and arrived at the laboratory three days afterwards. From the eight pre-pupae, seven adults of Chrysomya albiceps (Wiedemann, 1819) emerged and, from the two larvae, two adults of Hemilucilia segmentaria (Fabricius, 1805) were obtained. As necrophagous insects use corpses as a feeding resource, their development rate can be used as a tool to estimate the postmortem interval. The post-embryonary development stage of the immature collected on the body was estimated as the difference between the total development time and the time required for them to become adults in the lab. The estimated age of the maggots from both species and the minimum postmortem interval were four days. This is the first time that H. segmentaria is used to estimate the postmortem interval in a forensic case.

Necrophagous species of Diptera and Coleoptera in northeastern Brazil: state of the art and challenges for the Forensic Entomologist

Inventories on necrophagous insects carried out in Brazil encompass mostly species from the southeastern and central-western regions of the country. This review aims to produce the first checklist of necrophagous Diptera and Coleoptera species of forensic relevance in northeastern Brazil, an area that concentrates high rates of homicides. We performed a literature survey on scientific articles, theses and dissertations regarding necrophagous insect species in the region, and contacted scientists who develop research on forensic entomology. Fifty-two species of Diptera belonging to eight families with previous record of necrophagy were reported in the region: Sarcophagidae, Calliphoridae, Muscidae, Fanniidae, Piophilidae, Phoridae, Anthomyiidae and Stratiomyidae. Coleopteran species from six families of forensic relevance were registered, although taxonomical identification remained superficial. Bait traps were the most frequent methodology used, followed by collection on animal carcasses. Seven Dipteran species from two families were registered on human cadavers. All species had been previously reported in other Brazilian states and/or other countries, although none has been effectively used in legal procedures in the region. The status of research on forensic entomology in northeastern Brazil is incipient, and the checklist produced here contributes to the knowledge on the local diversity of necrophagous insects.

Comparative morphology and identification key for females of nine Sarcophagidae species (Diptera) with forensic importance in Southern Brazil

ABSTRACTThe identification of female flesh flies was always considered a difficult task since morphological descriptions and keys for females are rare. Even in a forensic entomology framework, where females play a major role, female flesh flies are usually not identified. In order to fill this gap in Southern Brazil fauna we provide detailed descriptions and key for the female of nine species included in four genera: Microcerella halli (Engel), Oxysarcodexia paulistanensis (Mattos), Oxysarcodexia riograndensis (Lopes), Peckia (Euboettcheria) australis (Townsend), Peckia(Euboettcheria) florencioi (Prado and Fonseca), Peckia (Pattonella) intermutans (Walker), Peckia(Pattonella) resona (Lopes), Peckia (Sarcodexia) lambens (Wiedemann), and Sarcophaga(Bercaea) africa (Wiedemann). These species are distinguished mainly by genital characters as tergite 6 divided or undivided, presence of tergite 8, spermatheca morphology and vaginal plate shape.

Bionomy of two flies of sanitary and forensic importance: Peckia (Sarcodexia) lambens (Wiedemann) and Oxysarcodexia amorosa (Schiner) (Diptera, Sarcophagidae)

ABSTRACTThis study aims to elucidate the bionomy of Peckia(Sarcodexia) lambens and Oxysarcodexia amorosa to provide data for medical, veterinary and forensic entomology analyses. We analyzed larval stage duration (L1–L3), weight of the mature larvae (L3), pupal stage duration, L1–adult duration, adult emergence and viability of larvae and adults of both species. Larval viability of P. (S.) lambens was 82% and the mean duration of the larval stage was 3.51 ± 0.99 days. The mature larvae had a mean weight of 33.67 ± 7.13 mg. The mean duration of the pupal stage was 8.26 ± 0.93 days and the mean duration of the L1–adult was 11.53 ± 1.22 days. Mean lifespan for females and males was 39.33 ± 1.52 and 57.33 ± 4.72 days, respectively. Larval viability of O. amorosa was 76% and mean duration of larval stage was 3.51 ± 0.64 days. Mature larvae had a mean weight of 28.28 ± 3.38 mg. Mean duration of the pupal stage was 10.14 ± 0.63 days and mean duration of the L1–adult was 13.60 ± 0.69 days. Mean lifespan for females and males was 83.66 ± 15.94 and 84.00 ± 19.97 days, respectively. Oxysarcodexia amorosa showed a L1–adult stage longer than P. (S.) lambens; however both species showed low viability. O. amorosa laid more larvae than P. (S.) lambens, this fact may occur because O. amorosa had longer life duration.

New records of Sarcophagidae species (Diptera) with forensic potential in Rio de Janeiro

ABSTRACTSarcophagidae species are frequent and abundant in the decomposition process of corpses and, consequently, play an important role as a tool for the application of Forensic Entomology. Helicobia pilifera Lopes, 1939, Microcerella erythropyga (Lopes, 1936), Oxysarcodexia fringidea Curran & Walley, 1934 and Peckia (Peckia) pexata(Wulp, 1895) were recorded for the first time in a Forensic Entomology experiment in Rio de Janeiro, using domestic pig carcasses as substrate.

Record of postmortem injuries caused by the Neotropical social wasp Agelaia fulvofasciata (Degeer) (Hymenoptera, Vespidae) on pig carcasses in the Eastern Amazon region: implications in forensic taphonomy

ABSTRACTPostmortem injuries are a source of misinterpretations in forensic analysis and therefore are subject matter of taphonomic interest. Many types of injuries can cause different artifacts, which deserve attention of the forensic pathologists when evaluating corpses, either at the crime scene or during an autopsy. Insects can be important biotaphonomic agents and their activity may result in artifacts that resemble antemortem injuries. Here, we describe postmortem injuries caused by the Neotropical wasp Agelaia fulvofasciata (Degeer, 1773) on domestic pig carcasses weighting 15 kg. The specimens showed extensive injuries to the lower lip, similar to lacerations, and some minor lesions on the snout and anus. In addition, we observed the same wasp species preying on larvae of Sarcophagidae (Peckia sp.). Besides causing postmortem injuries, the ability of this species to detect carcasses in the early and fresh decomposition stages should be noted. Thus, future applications aiming criminal, any biotaphonomic events caused by carrion insects need to be disclosed.

Coleoptera species of forensic importance from Brazil: an updated list

ABSTRACT A list of the Coleoptera of importance from Brazil, based on published records was compiled. The checklist contains 345 species of 16 families allocated to 16 states of the country. In addition, three species of two families are registered for the first time. The fauna of Coleoptera of forensic importance is still not entirely known and future collection efforts and taxonomic reviews could increase the number of known species considerably in the near future.

Occurrence of Poecilochirus austroasiaticus (Acari: Parasitidae) in forensic autopsies and its application on postmortem interval estimation

Despite the fact that mites were used at the dawn of forensic entomology to elucidate the postmortem interval, their use in current cases remains quite low for procedural reasons such as inadequate taxonomic knowledge. A special interest is focused on the phoretic stages of some mite species, because the phoront-host specificity allows us to deduce in many occasions the presence of the carrier (usually Diptera or Coleoptera) although it has not been seen in the sampling performed in situ or in the autopsy room. In this article, we describe two cases where Poecilochirus austroasiaticus Vitzthum (Acari: Parasitidae) was sampled in the autopsy room. In the first case, we could sample the host, Thanatophilus ruficornis (Küster) (Coleoptera: Silphidae), which was still carrying phoretic stages of the mite on the body. That attachment allowed, by observing starvation/feeding periods as a function of the digestive tract filling, the establishment of chronological cycles of phoretic behavior, showing maximum peaks of phoronts during arrival and departure from the corpse and the lowest values in the phase of host feeding. From the sarcosaprophagous fauna, we were able to determine in this case a minimum postmortem interval of 10 days. In the second case, we found no Silphidae at the place where the corpse was found or at the autopsy, but a postmortem interval of 13 days could be established by the high specificity of this interspecific relationship and the departure from the corpse of this family of Coleoptera.

Acarología forense [Forensic acarology]

Mites are a highly diversified group of chelicerates (arthropods) adapted to a broad spectrum of habitats and diets, presenting extreme specificity to habitats. They are considered to be important indicators of environmental conditions including those modified by human beings. Therefore, they can inform about the environment where a corpse has been exposed to, about the route of specific merchandises, as well as about other applied aspects of forensic entomology. It is not rare the presence of species adapted to cadaveric environments. Jean Pierre Mégnin, forensic veterinarian considered pioneer in the development of forensic entomology, conscious about the importance of mites as forensic indicators, was the first including mites in the decomposition process. For Mégnin, wave six was formed by mites only. Due to the increasing interest of forensic experts in including these organisms in their analysis of trace evidence, as mites are one of the most ubiquitous organisms, we have developed standards for the sampling, conservation and custody of mite evidence of forensic interest.

Necrophagy by the social wasp Agelaia pallipes (Hymenoptera : Vespidae, Epiponini): Possible forensic implications

The occurrence of 62 specimens of Agelaia pallipes caught in carrion traps using three types of baits (fish, cow liver and poultry viscera) in three different types of environments (rural, urban and forest area) in seven municipalities in Southeastern Brazil is reported here. This specific necrophagic behavior is discussed, since investigations concerning carrion wasps are scant in literature.

Bait and Habitat Preferences, and Temporal Variability of Social Wasps (Hymenoptera: Vespidae) Attracted to Vertebrate Carrion

In addition to feeding on carrion tissues and fluids, social wasps can also prey on immature and adult carrion flies, thereby reducing their populations and retarding the decomposition process of carcasses. In this study, we report on the occurrence and behavior of social wasps attracted to vertebrate carrion. The collections were made monthly from September 2006 to October 2007 in three environments (rural, urban, and forest) in six municipalities of southeast Brazil, using baited bottle traps. We collected Agelaia pallipes (Olivier, 1791) (n = 143), Agelaia vicina (Saussure, 1854) (n = 106), Agelaia multipicta (Haliday, 1836) (n = 18), and Polybia paulista Ihering, 1896 (n = 3). The wasps were observed feeding directly on the baits and preying on adult insects collected in the traps. Bait and habitat associations, temporal variability of social wasps, and possible forensic implications of their actions are discussed.

Breeding of Ornidia obesa (Diptera: Syrphidae: Eristalinae) on Pig Carcasses in Brazil

On Mho obesa F. (Diptera: Syrphidae) is usually neglected in forensic entomology, although adults are rather frequent on vertebrate carrion. In this study, conducted in southeastern Brazil in 2008, we used two pig carcasses, one killed by cocaine overdose and the other by shooting, to evaluate mainly the possible influences of the type of death on the larval development of O. obesa in the pig remains. We recorded the breeding of 218 adult specimens of this syrphid fly from the carcass killed by shooting, and none from the carcass killed by cocaine. These observations may open a new perspective for the use of O. obesa in forensic studies, considering its breeding preferences and its complete development on vertebrate carrion.

Determining the season of death from the family composition of insects infesting carrion

Determining the season of death by means of the composition of the families of insects infesting carrion is rarely attempted in forensic studies and has never been statistically modelled. For this reason, a baseline-category logit model is proposed for predicting the season of death as a function of whether the area where the carcass was exposed is sunlit or shaded and of the relative abundance of particular families of carrion insects (Calliphoridae, Fanniidae, Sarcophagidae, and Formicidae). The field study was conducted using rodent carcasses (20-252 g) in an urban forest in southeastern Brazil. Four carcasses (2 in a sunlit and 2 in a shaded area) were placed simultaneously at the study site, twice during each season from August 2003 through June 2004. The feasibility of the model, measured in terms of overall accuracy, is 64 +/- 14%. It is likely the proposed model will assist forensic teams in predicting the season of death in tropical ecosystems, without the need of identifying the species of specimens or the remains of carrion insects.

Scanning electron microscopy of third-instar sarcophagid (Diptera: Sarcophagidae) recovered from a mummified human corpse in Thailand

The third-instar of an unidentified sarcophagid, recovered from a mummified body of a 32-yr-old Thai male was examined using scanning electron microscopy (SEM). Although the morphological features of this larva are similar to the other sarcophagid larvae, some features could be helpful for species identification, which is a basic requirement for estimation of postmortem interval in forensic investigation. These features included number and arrangement of papillae on the anterior spiracle, structure of spines, size of circumspiracular tubercles at caudal segment and branching peculiarity of the posterior spiracular hairs. This information could benefit future identification of the sarcophagid larvae that exist in Thailand.