Tracheostomy wound myiasis in a patient with hypoxic encephalopathy.

•Tracheostomy wound myiasis is rarely observed in unconscious and immobile patients.•Maggots in the vicinity of the tracheostomy site should be closely monitored.•Controlling myiasis in hospitals requires fly control and patient fluid management.

The complete mitochondrial genome of Sarcophaga angarosinica (Diptera: Sarcophagidae).

Sarcophaga (Liosarcophaga) angarosinica (Rohdendorf, 1937) (Diptera: Sarcophagidae) is a species of both medical and ecological significance. In this study, the complete mitochondrial genome (mitogenome) of S. angarosinica was sequenced and characterized. The mitogenome has a total length of 15,215 bp, including 13 protein-coding genes, two ribosomal RNAs, 22 transfer RNAs, and an adenine and thymine-rich region. This mitogenome comprises 39.5% adenine, 9.4% guanine, 14.4% cytosine, and 36.8% thymine. Phylogenetic analysis revealed that S. angarosinica is closely related to Sarcophaga similis. This study enriches the genetic data on S. angarosinica and will contribute to establishing the phylogenetic relationships among flesh flies.

Diversity of flesh flies (Sarcophagidae, Sarcophaginae) of pond habitats in rural areas in the Croatian part of Baranja.

The diversity of grey flesh flies (Sarcophagidae: Sarcophaginae) from the Croatian part of Baranja was studied during 2019 to 2021, resulting in 37 species, of which the following are new for the area: Raviniapernix (Harris, 1780); Sarcophaga (Het.) depressifrons Zetterstedt, 1845; S. (Het.) filia Rondani, 1860; S. (Het.) haemorrhoides Böttcher, 1913; S. (Het.) pumila Meigen, 1826; S. (Het.) vagans Meigen, 1826; S. (Lis.) dux Thomson, 1869; S. (Lis.) tuberosa Pandellé, 1896; S. (Meh.) sexpunctata (Fabricius, 1805); S. (Pan.) protuberans Pandellé, 1896; S. (Sar.) carnaria (Linnaeus, 1758); S. (Sar.) variegata (Scopoli, 1763), and S. (Pse.) spinosa Villeneuve, 1912. New locality records are provided for 25 species. Sarcophaga (Sar.) croatica Baranov, 1941 was the most abundant with 37%, followed by S. (Sar.) lehmanni Müller, 1922 (21%), and S. (Pas.) albiceps Meigen, 1826 (5%), making up 63% of all collected specimens. Most species (35) were collected in locality of Zmajevac, while the fewest (3) were collected in Bilje locality. During this study, S. (Pse.) spinosa was recorded in Croatia for the first time. Combined with previous records, 42 species of flesh flies have been recorded from Croatian Baranja, which comprise 27% of the flesh flies known to occur in Croatia. The total number of species of the family Sarcophagidae currently known in Croatia has increased to 156.

The Study of Forensically Important Insects Recovered from Human Corpses in Taiwan.

A study of entomological specimens recovered from 117 human corpses in 114 forensic cases was conducted in Taiwan between 2011 and 2018. The comparisons and discussions of the entomological data were based on the locations (indoor vs. outdoor), environments (urban vs. suburban), season and decomposition stages of corpses. In the study, both morphology and DNA-based comparison methods were used to facilitate species identification. In total, nine families and twenty-two species were thus identified. The two most abundant fly species recovered from human corpses were Chrysomya megacephala (35.1%, 1735 out of 4949) and Chrysomya rufifacies (21.7%, 1072 out of 4949). As for case frequency, both the two were also the most common fly species (both 40%, 46 out of 114), particularly in outdoor cases (also both 74%, 25 out of 34). We found that Chrysomya pinguis and Lucilia porphyrina appeared in low temperature scenes in this study. Synthesiomyia nudiseta was the most common species detected on indoor (36%, 29 out of 80 cases) and urban (41%, 22 out of 54 cases) corpses. Sarcophagidae were strongly associated with urban environments (35%, 19 out of 54 cases), and Parasarcophaga (Liosarcophaga) dux, Liopygia ruficornis and Boettcherisca peregrina were the most frequent sarcophagid species collected from corpses. Hydrotaea spinigera was often found on corpses immersed in water (60%, three out of five cases) with advanced decay or remains stages. Megaselia scalaris was closely correlated with indoor cases (24%, 19 out of 80). In addition, Piophila megastigmata was collected from a corpse in the remains stage and the data represent the first report in Taiwan.

Detection of terbufos in cases of intoxication by means of entomotoxicological analysis using ATR-FTIR spectroscopy combined with chemometrics.

The detection of toxic substances in larvae from carcasses in an advanced stage of decomposition may help criminal expertise in elucidating the cause of death in suspected cases of poisoning. Terbufos (Counter®) or O,O-diethyl-S-[(tert-butylsulfanyl)methyl] phosphorodithioate is an insecticide and systemic nematicide, which has very high toxicity from an acute point of view (oral LD50 in rodents ranging from 1.4 to 9.2 mg/kg) that has been marketed irregularly and indiscriminately in Brazil as a rodenticide, often being used to practice homicides. The present study aims to evaluate the use of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy to detect traces of terbufos pesticide in fly larvae (Sarcophagidae). ATR-FTIR spectra of scavenger fly larvae from control (n = 31) and intoxicated (n = 80) groups were collected and submitted to chemometric analysis by means of multivariate classification using principal component analysis with quadratic discriminant analysis (PCA-QDA), successive projections algorithm with quadratic discriminant analysis (SPA-QDA) and genetic algorithm with quadratic discriminant analysis (GA-QDA) in order to distinguish between control and intoxicated groups. All discriminant models showed sensitivity and specificity above 90%, with the GA-QDA model showing the best performance with 98.9% sensitivity and specificity. The proposed methodology proved to be sensitive and promising for the detection of terbufos in scavenger fly larvae from intoxicated rat carcasses. In addition, the non-destructive nature of the ATR-FTIR technique may be useful in preserving the forensic evidence, meeting the precepts of the chain of custody and allowing for counter-proof.

Comparative Mitogenomics of Flesh Flies: Implications for Phylogeny.

Flesh flies (Diptera: Sarcophagidae) represent a rapid radiation belonging to the Calyptratae. With more than 3000 known species, they are extraordinarily diverse in terms of their breeding habits and are therefore of particular importance in human and veterinary medicine, forensics, and ecology. To better comprehend the phylogenetic relationships and evolutionary characteristics of the Sarcophagidae, we sequenced the complete mitochondrial genomes of five species of flesh flies and performed mitogenomic comparisons amongst the three subfamilies. The mitochondrial genomes match the hypothetical condition of the insect ancestor in terms of gene content and gene arrangement. The evolutionary rates of the subfamilies of Sarcophagidae differ significantly, with Miltogramminae exhibiting a higher rate than the other two subfamilies. The monophyly of the Sarcophagidae and each subfamily is strongly supported by phylogenetic analysis, with the subfamily-level relationship inferred as (Sarcophaginae, (Miltogramminae, Paramacronychiinae)). This study suggests that phylogenetic analysis based on mitochondrial genomes may not be appropriate for rapidly evolving groups such as Miltogramminae and that the third-codon positions could play a considerable role in reconstructing the phylogeny of Sarcophagidae. The protein-coding genes ND2 and ND6 have the potential to be employed as DNA markers for species identification and delimitation in flesh flies.

The first reported case of accidental intestinal myiasis in a domestic dog by the flesh fly, Sarcophaga africa (Wiedeman, 1824).

Myiasis occurs when fly larvae, or maggots, feed on the tissue, secretions or digestive content of a live vertebrate. Here, a rare case of accidental intestinal or enteric myiasis is reported in a domestic dog. The species of fly is molecularly identified as Sarcophaga africa (Wiedeman, 1824) using the barcoding region of cytochrome oxidase I (COI). A brief critique on the usage of the term "pseudomyiasis" is provided and the complex taxonomy of S. africa is briefly summarised in order to shed light on the erroneous use of S. cruenata and S. haemorrhoidalis with obvious downstream effects. Finally, a comparative assessment to the limited cases in the literature is provided. These few cases are however highly fragmented and our understanding of accidental intestinal myiasis and the clinical manifestations thereof remain incomplete.

Characterization of anti-microbial peptides and proteins from maggots of Calliphoridae and Sarcophagidae fly species (Diptera).

Removal of infected wounds using maggots has been known for centuries. Early research has shown that the maggot exosecretion, whole body, and fecal waste products of Calliphoridae and Sarcophagidae species contain a variety of alkaline peptides capable of inhibiting bacterial growth. Since the wide application of antibiotics such as penicillin, a number of bacterial infections have become insensitive to antibiotic treatment. In many of these instances, maggot therapy has been successfully applied for the treatment of chronic wounds. To identify and compare the expression patterns of anti-microbial peptides (AMPs) from some dipteran species, transcriptome analyses were conducted for the maggots of 11 Calliphoridae and Sarcophagidae species. Species of the subfamily Calliphorinae showed relatively higher expression levels of AMPs and anti-microbial proteins compared with those of Luciliinae and Sarcophagidae species. Furthermore, among all of the dipteran species examined, Lucilia illustris exhibited the highest transcription levels of AMPs. Cecropin A2 and defensin, whose expression levels were the highest among the anti-microbial peptides, were synthesized to test their biological activity. The synthesized peptides showed anti-microbial activities without hemolytic activities. In particular, cecropin A2 of L. illustris exhibited the highest anti-microbial activity against all of the bacteria and fungi examined, thereby possessing the potential to be developed as a new alternative to antibiotics. This comparative transcriptomic study may provide new insights into anti-microbial compositions of some dipteran species.

Traumatic myiasis by Wohlfahrtia magnifica in sheep flocks from southeastern Spain: prevalence and risk factors.

Wohlfahrtia magnifica (Diptera: Sarcophagidae) is an obligate myiasis-causing fly of livestock that is widely distributed throughout the Mediterranean basin. A total of 73 683 sheep from 122 flocks in Albacete Province (southeastern [SE] Spain) were examined to detect active traumatic myiasis. The influence of several individual and flock factors on the prevalence was also assessed. The overall flock prevalence of traumatic myiasis was 95.9%, with an individual prevalence of 7.1%. Wohlfahrtia magnifica was identified in all of the positive animals except one that was infested by Lucilia sericata (Diptera: Calliphoridae). Adults of both genders showed a higher risk of infestation than juveniles, whereas males of all ages displayed an increased risk of infestation than females of all ages; the existence of a lambing building on the farm, poor husbandry facilities and the location area were also identified as risk factors. Prevalence was highest in the summer, and the fly season lasted from March to November. Genitalia were the main location of infestation in males (94.4%) and females (76.3%). Our results reveal that traumatic myiasis by W. magnifica is widespread in southeastern Spain, hence preventive measures minimizing the attractiveness of sheep to gravid flies are necessary to avoid health and welfare problems and significant production losses in sheep flocks.

Effect of different doses of the catecholamine epinephrine on antioxidant responses of larvae of the flesh fly Sarcophaga dux.

The production and use of pharmaceutical products have increased over the past decades, and several are considered potential or proved hazardous wastes. When contaminating the environment, they can severely impact biodiversity. The catecholamine epinephrine (adrenaline) is no exception. Epinephrine can be administered as growth promoter in cattle, and is used for anaphylaxis treatment in human. While a range of studies has examined the effects of this catecholamine on vertebrate tissues, and evidenced that it can disrupt the oxidative stress status, the effects epinephrine could have on insects have remained poorly considered. Here, we examined the physiological effects of different concentrations (0, 25, 50, and 100 µg/mL) of epinephrine on larvae of the flesh fly Sarcophaga dux. Following experimental treatments, levels of H2O2, GSH, CAT, GPx, and CEH were measured from the fat body, cuticle, gut, and hemolymph of 3rd instars. Significant differences are reported for these physiological endpoints among the considered body compartments, and epinephrine concentrations. Epinephrine treatments did not increase reactive oxygen species production (H2O2 amounts), except for gut tissues. Increased levels of GSH suggest that epinephrine may have enhanced glucose metabolism and flux towards the pentose phosphate pathway, while reducing glutamine oxidation. CAT activity was slightly increased when the concentration of epinephrine was higher. The decreased GPx activity in the fat body was consistent with GSH variations. In sum, the injection of epinephrine seemed to elicit the antioxidant response in S. dux larvae, in turn attenuating ROS production.

Forensic entomology when the evidence is "no insect." Best carrion fly species for predicting maximum postmortem interval in the United Arab Emirates.

The carrion insect species that most quickly deposit offspring on a corpse are, when available, likely to yield a more useful estimate of postmortem interval (PMI) compared to later arrivals. This is in part because the age of the oldest larva will be as close as possible to the PMI when doing a development analysis, and because the preappearance interval (PAI), the time the corpse was exposed before insect colonization, corresponds to the narrowest window of time since death for an insect-free corpse when doing a succession analysis. Given replicated training data a prediction of exposure time for a corpse can be in the form of a confidence set, and the maximum value of that set for an insect-free corpse is a probabilistic version of PAI. To discover the insect species likely to be useful in the early postmortem period in the United Arab Emirates we exposed 216 rat carcasses outdoors at two sites in Dubai over three-day periods during winter. Rats were sampled twice each day without replacement and kept in the lab to allow carrion insects to complete development to the adult stage. The fly species produced in this way were Sarcophaga dux, S. ruficornis, Wohlfahrtia nuba, W. indigens (Sarcophagidae), Chrysomya albiceps (Calliphoridae), and Musca domestica (Muscidae). To the best of our knowledge this is the first record of W. indigens larvae feeding on carrion. While adult C. albiceps and M. domestica were abundant on the carcasses, C. albiceps colonized too slowly to be useful for this type of succession analysis within this time frame, and M. domestica emerged from a single rat. The Sarcophagidae were rapid colonizers, and under these conditions the probability is>90% that a carcass would remain free of S. dux larvae not more than 57 h and free of W. nuba larvae for not more than 51 h.

Landscape distribution and abundance of animal-associated adult filth flies on commercial swine facilities in North Carolina, US.

Filth flies associated with animal production transmit pathogens to humans and animals, propagate antimicrobial resistance in microbial communities and provoke nuisance litigation. Although dispersal of flies from facilities is often responsible for these negative effects, filth fly research on swine facilities has been limited to within the barns. Filth fly adaptations in space and time, as well as influences of abiotic and biotic factors impact distribution and abundance of animal-associated filth flies on swine production facilities. In this study, fly surveillance was conducted around four swine facilities in Bladen County, North Carolina, U.S.A. from January 2019 to October 2019. Traps were replaced weekly and animal-associated filth flies were identified. Flies were grouped for comparison based on biology and differences in pest management strategies. There were distinct differences in abundance and spatial distribution of different filth fly groups on the swine facilities, which are likely linked to environmental factors like spatial relation to crop production and species phenology. The impact of the observed temporal and spatial distribution and abundance is discussed in the context of filth fly management.

Biological Control of Pest Non-Marine Molluscs: A Pacific Perspective on Risks to Non-Target Organisms.

Classic biological control of pest non-marine molluscs has a long history of disastrous outcomes, and despite claims to the contrary, few advances have been made to ensure that contemporary biocontrol efforts targeting molluscs are safe and effective. For more than half a century, malacologists have warned of the dangers in applying practices developed in the field of insect biological control, where biocontrol agents are often highly host-specific, to the use of generalist predators and parasites against non-marine mollusc pests. Unfortunately, many of the lessons that should have been learned from these failed biocontrol programs have not been rigorously applied to contemporary efforts. Here, we briefly review the failures of past non-marine mollusc biocontrol efforts in the Pacific islands and their adverse environmental impacts that continue to reverberate across ecosystems. We highlight the fact that none of these past programs has ever been demonstrated to be effective against targeted species, and at least two (the snails Euglandina spp. and the flatworm Platydemus manokwari) are implicated in the extinction of hundreds of snail species endemic to Pacific islands. We also highlight other recent efforts, including the proposed use of sarcophagid flies and nematodes in the genus Phasmarhabditis, that clearly illustrate the false claims that past bad practices are not being repeated. We are not making the claim that biocontrol programs can never be safe and effective. Instead, we hope that in highlighting the need for robust controls, clear and measurable definitions of success, and a broader understanding of ecosystem level interactions within a rigorous scientific framework are all necessary before claims of success can be made by biocontrol advocates. Without such amendments to contemporary biocontrol programs, it will be impossible to avoid repeating the failures of non-marine mollusc biocontrol programs to date.

Museomics and phylogenomics with protein-encoding ultraconserved elements illuminate the evolution of life history and phallic morphology of flesh flies (Diptera: Sarcophagidae).

BACKGROUND: The common name of the Flesh flies (Sarcophagidae) usually relates them with organisms feeding on decomposing organic matter, although the biology of one of the largest radiations among insects also includes predation, coprophagy, and even kleptoparasitism. The question of whether the ancestor of all sarcophagids was a predator or a decomposer, or in association to which host have sarcophagids evolved, has thus always piqued the curiosity of flesh fly specialists. Such curiosity has often been hindered by both the impossibility of having a well-supported phylogeny of Sarcophagidae and its sister group to trace live habits and the scarcity of information on the biology of the group. Using a phylogenomic dataset of protein-encoding ultraconserved elements from representatives of all three subfamilies of Sarcophagidae as ingroup and a large Calyptratae outgroup, a robust phylogenetic framework and timescale are generated to understand flesh fly systematics and the evolution of their life histories. RESULTS: The evolutionary history for Sarcophagidae reconstructed here differs considerably from previous hypotheses. Within subfamily Sarcophaginae, a group of predatory flies, including genera Lepidodexia and Boettcheria, emerged as sister-group to the rest of Sarcophaginae. The genera Oxysarcodexia, Ravinia, and Tricharaea, long considered archaic and early-branching coprophagous and sarcosaprophagous lineages, were found nested well within the Sarcophaginae as sister-group to the sarcosaprophagous Microcerella. Predation on invertebrates is suggested as the ancestral and dominant strategy throughout the early evolution of flesh flies. Several transitions from predation to sarcosaprophagy and coprophagy occur across the sarcophagid phylogenetic tree, in contrast with almost no transitions from sarcosaprophagy or coprophagy to predatory habits. Regarding the morphological evolution of flesh flies, there might be a concerted evolution of male genitalia traits, such as the phallotrema position and the juxta, or the vesica and the folding of the phallotrema. One diversification rate shift was inferred in the evolution of sarcophagids, which is related to the origin of genus Sarcophaga. CONCLUSIONS: This study has a significant impact on understanding sarcophagid evolution and highlights the importance of having a robust phylogenetic framework to reconstruct the ancestral character state of biological and morphological characters. I discuss the evolution of life histories of the family in relation to their hosts or substrates and outline how sarcosaprophagy, coprophagy, and kleptoparasitism behavior on various hosts may have evolved from predation on invertebrates. This study provides a phylogenetic framework for further physiological and comparative genomic work between predatory, sarcosaprophagous, coprophagous, and kleptoparasitic lineages, which could also have significant implications for the evolution of diverse life histories in other Diptera.

DNA-based and taxonomic identification of forensically important Sarcophagidae (Diptera) in southeastern Spain.

Studying dipterans at the scene of a death can provide essential information for interpreting the evidence and help to reconstruct the events happened to a corpse in the past. Molecular tools have been employed for identification at specific levels in the cases of cryptic species or poorly conserved specimens. Identification of specimens is essential in forensic entomology since each species has a specific growth rate, which determines the calculation of the minimum post mortem interval (minPMI). In addition, phylogeographic reconstruction within a species can help to differentiate the haplotypes from a geographic area, thereby helping to clarify the possible relocation of a corpse. The morphological identification of Sarcophagidae species is often difficult, especially for the females. This is an important Diptera family since some of its species are among the first to reach a corpse, especially in warm areas. In this study, we compared the sarcophagids found in human corpses in forensic cases in Alicante (southeast of Spain) with specimens collected from baited traps in the same area and surrounding provinces. In total, 189 specimens were collected, comprising 72 from forensic cases and 117 from baited traps. Molecular identification was conducted by sequencing the cox1 mitochondrial gene and analyzing the sequences using ABGD, GMYC, and BIN species delimitation methods. The median joining algorithm in the PopART program was used to construct phylogeographic networks. Eight species in the family Sarcophagidae were identified. The most widely collected species were Sarcophaga argyrostoma and Sarcophaga tibialis. The haplotype networks obtained for these species did not indicate a clear geographic distribution of haplotypes. The S. argyrostoma samples from Alcoy were clearly isolated. The results demonstrated that this method is useful for identifying Sarcophagidae samples in forensic investigations and it can be employed for minPMI estimation.

Comparative analysis of the mitochondrial genomes of flesh flies and their evolutionary implication.

Flesh flies (Diptera: Sarcophagidae) include a large and widely distributed rapid radiation within the Calyptratae. They are vital for the ecosystem, as well as economic, forensic, and evolutionary studies, because of their extremely diverse habits as larvae. Phylogenetic studies of Sarcophagidae have been reaching convergence, which leads the opportunity to elucidate the evolution of these fast-evolving insects from the perspective of mitochondrial genome. Complete mitochondrial genomes of eight species were sequenced, and comparative mitochondrial genomic analysis between subfamilies were conducted. Mitochondrial genomes of these flesh flies are conserved in gene content with gene arrangement, same as the inferred ancestral insect, and the nucleotide composition is highly biased towards A + T like other flesh flies. The evolutionary rates of Sarcophagidae vary considerably across subfamilies, with that of Miltogramminae higher than the other two subfamilies. Phylogenetic analysis strongly supports monophyly of Sarcophagidae and each subfamily, with subfamily-level relationship inferred as (Sarcophaginae, (Miltogramminae, Paramacronychiinae)). The main topological inconsistency of all reconstructions is the relationship within Miltogramminae and Sarcophaga, which might be caused by their rapid evolution. Our study indicates that the mitochondrial genomes of flesh flies are highly conserved, and they are practically useful for phylogenetic inference of calyptrates.

Random forests for predicting species identity of forensically important blow flies (Diptera: Calliphoridae) and flesh flies (Diptera: Sarcophagidae) using geometric morphometric data: Proof of concept.

Wing shape variation has been shown to be useful for delineating forensically important fly species in two Diptera families: Calliphoridae and Sarcophagidae. Compared to DNA-based identification, the cost of geometric morphometric data acquisition and analysis is relatively much lower because the tools required are basic, and stable softwares are available. However, to date, an explicit demonstration of using wing geometric morphometric data for species identity prediction in these two families remains lacking. Here, geometric morphometric data from 19 homologous landmarks on the left wing of males from seven species of Calliphoridae (n = 55), and eight species of Sarcophagidae (n = 40) were obtained and processed using Generalized Procrustes Analysis. Allometric effect was removed by regressing centroid size (in log10 ) against the Procrustes coordinates. Subsequently, principal component analysis of the allometry-adjusted Procrustes variables was done, with the first 15 principal components used to train a random forests model for species prediction. Using a real test sample consisting of 33 male fly specimens collected around a human corpse at a crime scene, the estimated percentage of concordance between species identities predicted using the random forests model and those inferred using DNA-based identification was about 80.6% (approximate 95% confidence interval = [68.9%, 92.2%]). In contrast, baseline concordance using naive majority class prediction was 36.4%. The results provide proof of concept that geometric morphometric data has good potential to complement morphological and DNA-based identification of blow flies and flesh flies in forensic work.

Wound Myiasis in Diabetic Foot Ulcer: Calliphoridae and Sarcophagidae Family.

BACKGROUND: Myiasis is a parasitic infestation of tissues or body cavities of mammals with dipterous larvae. The patients with diabetic foot ulcers are more vulnerable to acquiring infestation; however, the infestation may be neglected and mistreated in some cases. METHODS: Data were collected of twelve myiasis cases with diabetic foot ulcers in Nazli-Selim Eren Chronic Wound and Infections Care Unit, Aydin, Turkey between 2017 and 2019. Demographic, clinical characteristics of the patients and clinical examination of the wound were recorded. To morphology-based identification method of the agents, the developmental stages of the maggots were examined. RESULTS: The cases aged between 46 and 81 years (10 males, two females). Eight of the larvae collected from wounds had Calliphoridae and four had Sarcophagidae family. The larvae were infested right/left foot sole, thumb, ankle, and mostly left toes. The number of larvae collected from the cases ranged from 2 to 48. Third-stage larvae (L3) were mostly detected. Mixed (L1-L2, L2-L3) larvae were detected in a patient. The infestations were more common in July and August. According to the score of Infectious Diseases Society of America (IDSA), ten (83%) cases had moderate and two (17%) cases were mild diabetic foot infections (DFIs). CONCLUSION: Diabetic foot ulcers should be evaluated in terms of myiasis. This was the first study in our province indicating that myiasis should not be neglected and different species of flies were responsible for myiasis cases.

Seasonal Fluctuations in Sarcophagidae (Diptera: Calyptratae) Assemblages in the Humid Chaco Ecoregion, Argentina.

The seasonal fluctuations of flesh fly (Diptera: Sarcophagidae) assemblages were investigated from March 2015 to February 2016 in five habitat types in the Humid Chaco ecoregion, Chaco Province, Argentina. Three of the habitats were anthropized: an urban area, a cattle farm, and an alfalfa crop; and two were natural: a savanna and a forest. Flesh flies were collected monthly at 25 sampling points, five per habitat. In total, 5,790 male specimens comprising 55 species distributed in 15 genera were collected. The assemblage composition of flesh flies in each habitat and season was analyzed in terms of abundance, species richness, and diversity. In addition, the correlation between these community parameters and climatic factors (precipitation 7 and 14 d before samplings, temperature, and relative humidity) were evaluated in each habitat. The highest abundance and species richness of Sarcophagidae were registered in May (autumn) and June (winter), respectively. The lowest diversity values were observed between August and September (end of winter and early spring) in all habitats. However, flesh flies were present and well represented (in terms of species richness) throughout the year in all habitat types. Fluctuations in the abundance of the most abundant species collected were analyzed. The climatic factors were correlated with diversity and species richness in the urban, cattle farm, and savanna habitats. This study revealed that flesh fly assemblages differed temporally between different types of habitats in accordance with climatic factors and microclimate conditions.

Differential Ability of Necrophagous Diptera to Colonize Concealed Resources: Empirical Evidence From a Field Experiment in Brazil.

Field studies in forensic entomology seem to assume that a cadaver is a resource equally accessible to flies, irrespective of the species' size, behavior, and sensorial capacity. We aimed to challenge this assumption by experimentally manipulating baited traps in order to test whether the accessibility to decomposing baits is related to the following: (i) the diversity of necrophagous dipterans; (ii) the body size of adults; and (iii) the female sexual maturity stage. The experiment was performed in a rainforest fragment in Northeastern Brazil, in an area characterized by high levels of homicides. Traps baited with decomposing chicken liver had three levels of access: easy (six openings on the trap), intermediate (three), and difficult (one). A total of 750 adults of Calliphoridae, Fanniidae, Muscidae, Phoridae, and Sarcophagidae were collected. Of the 18 species recorded, Megaselia scalaris was the most abundant (46.8%) followed by Lucilia eximia (29.7%) and Chrysomya megacephala (9.8%). The number of species increased significantly with the accessibility level, but overall abundance did not differ, as a consequence of the numerical dominance of M. scalaris. A strong female bias (>91%) was observed in all traps. For Calliphoridae specimens, 90% of the females caught in traps under intermediate and difficult access were sexually mature. By empirically demonstrating that limitation of access and exclusion of visual stimuli do not deter several dipteran species from reaching a substrate, we expand the knowledge on the factors that can shape the colonization of concealed human cadavers, including variables such as insect size and stage of sexual maturity.