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Flesh flies comprise a large fly family distributed worldwide that has great importance for forensic entomology. A robust and updated checklist of Sarcophaginae flies recorded in Southern Brazil is presented, based on material collected in the Rio Grande do Sul state and on a literature review. The forensic importance (high, moderate, or none) of the recorded flesh flies for estimating the postmortem interval (PMI) or inferring cases of neglect was determined based on their ecological habits. A total of 2,831 specimens representing 38 taxa were collected from three studies. Oxysarcodexia was the most abundant and species-rich genus in all three studies. Dexosarcophaga carvalhoi (Lopes) was registered for the first time in Southern Brazil. The checklist for Southern Brazil comprises 91 species distributed in 19 genera, with Oxysarcodexia, Peckia, and Lepidodexia representing the richest genera. Considering the importance of species for PMI estimation, 10, 42, and 39 species were classified as having high, moderate, or no forensic relevance, respectively. Moreover, five myiasis-causing sarcophagine flies recorded in Southern Brazil were considered to have the potential to reveal cases of neglect or mistreatment. This study revealed that Microcerella halli (Engel) and Peckia (Euboettcheria) australis (Townsend) are the most important species for PMI estimation in Southern Brazil, as they are often found breeding in corpses in this region.

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Although different feeding habits have been reported for Sarcophaginae (Diptera, Sarcophagidae), most species are associated with decomposing organic matter such as feces and decaying corpses. This study provides the synanthropy index for males of species of Sarcophaginae collected during a 12-mo period in three different environments (urban, rural, and wild) of the state of Rio Grande do Sul, in Southern Brazil, linking this parameter with the sanitary issue. This article also investigated the presence of pathogenic bacteria on the external surface of Oxysarcodexia paulistanensis (Mattos), the most abundant species collected using a sanitized entomological net. Almost all the species collected most abundantly, including O. paulistanensis (n = 241), Ravinia advena (Walker) (n = 87), and O. thornax (Walker) (n = 58), were classified as synanthropic; O. thornax was the species with the highest synanthropy index (+80.3). Escherichia coli (Escherich), Shigella spp. (Enterobacteriaceae), and Staphylococcus aureus (Rosenbach) (Staphylococcaceae) were isolated and identified from the external surface of O. paulistanensis. The isolation and identification of pathogenic bacteria, and their synanthropic behavior, adds weight to potential role of some flesh flies, as O. paulistanensis, in a sanitary context.

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RESUMO

Oxysarcodexia is one of the Neotropical richest genera within the Sarcophagidae family. Medical, veterinary and forensic importance of these flies are due to their association with corpses, cases of myiasis in humans and domestic animals, and being pathogen carriers. Regarding morphological identification, molecular techniques, especially the DNA-based ones, arise as useful alternatives or complementary methodologies for species identification. Thus, in this study we aimed to investigate the potential of the COI marker (barcode region) to delimit Oxysarcodexia species in comparison with the morphological identification criteria. A COI fragment was amplified and the length of the sequences after alignment were of 648bp (149 parsimoniously informative variable sites). According to the Neighbor-Joining phylogenetic tree, specimens of the same morphological species were clustered in monophyletic clades (82-100% bootstrap branch support). Species-level resolution thus achieved was successful, despite low interspecific divergence (1.8-2.3%) and since interspecific variation was higher than intraspecific divergence (0.1-1.2%). Therefore, the use of COI barcode sequences supports differentiation and identification of the Oxysarcodexia species studied.

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Immunohistochemistry (IHC) technique is an alternative toxicological analysis to detect drugs in insects of forensic importance, but it requires thorough histological procedures. In this study, we tested different fixatives--phosphate-buffered paraformaldehyde 4% (PP), Carnoy's fluid (CF), Kahle's solution (KS), ethanol in different concentrations, and ethanol associated to PP and CF, time of fixation and histological processes for dipteran larvae's tissue, aiming to develop a sample preparation protocol for IHC application. A suitable fixation was achieved using PP for 12 and 24 h, CF for 3 h, 70% ethanol for 19 days, and 70% ethanol/CF for 2 h/3 h. Postfixation using negative pressure, two immersions in xylene for 30 min each, and one in xylene plus paraffin for 45 min increased tissue preservation. An immunohistochemical test for cocaine detection was performed using monoclonal benzoylecgonine antibody from mouse, peroxidase-conjugated anti-mouse IgG and visualized by 3,3'-diaminobenzidine method showed these histological procedures didn't compromise antigenicity.

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Carrion breeding insects may be of great utility in crimes briefing. Studies on forensic entomology are restricted to few localities in Brazil and very few of them were done in the cerrado vegetation (a type of Savannah) until now. This work aimed to survey the main species of dipterans associated with the decomposition process of Sus scrofa and the insect succession pattern in carcasses in the Cerrado. The study was carried out in the dry and humid season of the year, in two cerrado vegetation profiles in Uberlândia, MG. Two pig carcasses were placed in each vegetation profile and time period of the year. The decomposition process was slower and insects were more abundant in the dry season. Differences in temperature, air humidity and pluvial precipitation seemed to be the main physical factors responsible for the differences in the time of decomposition of the pig carcasses between the two seasons. Fourteen species of dipterans (59,467 specimens) bred in the decomposing carcasses. Chrysomya albiceps (Wiedemann) was the species more abundantly breed in the two periods. The other species that breed in the carcasses were: C. putoria (Wiedemann), Hemilucilia segmentaria(Fabricius), Lucilia eximia(Wiedemann) (Calliphoridae), Peckia (Pattonella) intermutans(Walker), Peckia (Squamatoides) trivitatta(Curran), Sarcodexia lambens(Wiedemann) (Sarcophagidae), Musca domestica(L.), Ophyra aenescens(Wiedemann), Stomoxys calcitransL. (Muscidae), Fannia pusio(Wiedemann), Fannia sp. (Fanniidae), Hermetia illuscens L. (Stratiomyidae) and Phoridae sp. The Cerrado of this region presents many dipterans potential forensic indicators.

Os insetos podem ser de grande utilidade no auxílio de elucidações de crimes. Estudos de entomologia forense ainda estão restritos a poucas localidades no Brasil e são escassos na vegetação de cerrado. Este estudo teve por objetivo identificar as principais espécies de Diptera associadas ao processo de decomposição de carcaças de suínos Sus scrofa e o padrão de sucessão de insetos nesse tipo de substrato. Foram realizados dois experimentos nos períodos seco e úmido do ano em duas áreas de cerrado no município de Uberlândia, MG. Foram utilizadas duas carcaças de suínos em cada ambiente e período do ano. O processo de decomposição foi mais lento no período seco, assim como a maior quantidade de insetos coletados. Diferenças na temperatura, umidade e precipitação pluviométrica parecem ter sido os principais responsáveis pelas diferenças nos tempos de decomposição entre os dois períodos do ano. Quatorze espécies (59.467 espécimes) foram coletadas nas carcaças em decomposição. Chrysomya albiceps (Wiedemann) was the species more abundantly breed in the two periods. The other species that breed in the carcasses were: C. putoria (Wiedemann), Hemilucilia segmentaria(Fabricius), Lucilia eximia(Wiedemann) (Calliphoridae), Peckia (Pattonella) intermutans(Walker), Peckia (Squamatoides) trivitatta(Curran), Sarcodexia lambens(Wiedemann) (Sarcophagidae), Musca domestica(L.), Ophyra aenescens(Wiedemann), Stomoxys calcitransL. (Muscidae), Fannia pusio(Wiedemann), Fannia sp. (Fanniidae), Hermetia illuscens L. (Stratiomyidae) e Phoridae sp. O cerrado dessa região apresenta vários dípteros potenciais indicadores forenses.

Assuntos

RESUMO

Carrion breeding insects may be of great utility in crimes briefing. Studies on forensic entomology are restricted to few localities in Brazil and very few of them were done in the cerrado vegetation (a type of Savannah) until now. This work aimed to survey the main species of dipterans associated with the decomposition process of Sus scrofa and the insect succession pattern in carcasses in the Cerrado. The study was carried out in the dry and humid season of the year, in two cerrado vegetation profiles in Uberlândia, MG. Two pig carcasses were placed in each vegetation profile and time period of the year. The decomposition process was slower and insects were more abundant in the dry season. Differences in temperature, air humidity and pluvial precipitation seemed to be the main physical factors responsible for the differences in the time of decomposition of the pig carcasses between the two seasons. Fourteen species of dipterans (59,467 specimens) bred in the decomposing carcasses. Chrysomya albiceps (Wiedemann) was the species more abundantly breed in the two periods. The other species that breed in the carcasses were: C. putoria (Wiedemann), Hemilucilia segmentaria(Fabricius), Lucilia eximia(Wiedemann) (Calliphoridae), Peckia (Pattonella) intermutans(Walker), Peckia (Squamatoides) trivitatta(Curran), Sarcodexia lambens(Wiedemann) (Sarcophagidae), Musca domestica(L.), Ophyra aenescens(Wiedemann), Stomoxys calcitransL. (Muscidae), Fannia pusio(Wiedemann), Fannia sp. (Fanniidae), Hermetia illuscens L. (Stratiomyidae) and Phoridae sp. The Cerrado of this region presents many dipterans potential forensic indicators.

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