Edge effects on the blowfly fauna (Diptera, Calliphoridae) of the Tijuca National Park, Rio de Janeiro, Brazil

Deciphering the impact of microenvironmental factors on cuticular hydrocarbon degradation in Lucilia sericata empty Puparia: Bridging ecological and forensic entomological perspectives using machine learning models

Blow flies (Calliphoridae) play essential ecological roles in nutrient recycling by consuming decaying organic matter. They serve as valuable bioindicators in ecosystem management and forensic entomology, with their unique feeding behavior leading to the accumulation of environmental pollutants in their cuticular hydrocarbons (CHCs), making them potential indicators of exposure history. This study focuses on CHC degradation dynamics in empty puparia of Lucilia sericata under different environmental conditions for up to 90 days. The three distinct conditions were considered: outdoor-buried, outdoor-above-ground, and indoor environments. Five predominant CHCs, n-Pentacosane (n-C25), n-Hexacosane (n-C26), n-Heptacosane (n-C27), n-Octacosane (n-C28), and n-Nonacosane (n-C29), were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). The findings revealed variations in CHC concentrations over time, influenced by environmental factors, with significant differences at different time points. Correlation heatmap analysis indicated negative correlations between weathering time and certain CHCs, suggesting decreasing concentrations over time. Machine learning techniques Support Vector Machine (SVM), Multilayer Perceptron (MLP), and eXtreme Gradient Boosting (XGBoost) models explored the potential of CHCs as age indicators. SVM achieved an R-squared value of 0.991, demonstrating high accuracy in age estimation based on CHC concentrations. MLP also exhibited satisfactory performance in outdoor conditions, while SVM and MLP yielded unsatisfactory results indoors due to the lack of significant CHC variations. After comprehensive model selection and performance evaluations, it was found that the XGBoost model excelled in capturing the patterns in all three datasets. This study bridges the gap between baseline and ecological/forensic use of empty puparia, offering valuable insights into the potential of CHCs in environmental monitoring and investigations. Understanding CHCs' stability and degradation enhances blow flies' utility as bioindicators for pollutants and exposure history, benefiting environmental monitoring and forensic entomology.

Faunistic Analysis of Calliphoridae and Mesembrinellidae (Diptera: Oestroidea) at Different Stages of Bovine Liver Decomposition in the State of Rio de Janeiro

Performing quantitative sampling and determining faunistic analyses of dipterans is of fundamental importance in the analysis of ecological behavior, such as population dynamics and diversity, among other factors, for exotic and native species of necrophagous dipterans, so it is important to observe the type of bait used in traps to capture these dipteran species. This work aims to study structural parameters and faunistic indices of the diversity of Calliphoridae and Mesembrinellidae species as well as the abundance and diversity of species attracted to liver in two stages of decomposition: fresh liver and liver at 48 h of putrefaction. A total of 2826 dipterans were collected during the period from May 2021 to February 2022. We observed that liver in decomposition for 48 h was more attractive in the forest and rural environments, while fresh liver showed greater attractiveness in the urban environment; however, no statistical difference was evidenced between the attractiveness in the different environments. The Mesembrinellidae family and the species Lucilia eximia (Wiedemann, 1819) were collected mostly from deteriorated liver, while Cochliomyia macellaria (Fabricius, 1775) showed no preference for any liver decomposition stage. The Wilcoxon test indicated that there is a significant difference between the preferences for putrefied bait in Mesembrinellidae, while in Calliphoridae, there was no preference for type of bait. The faunistic analysis showed that richness in the forest area was always higher when compared to the urban and rural areas. Laneela nigripes (Guimarães, 1977) and Mesembrinella bellardiana (Aldrich, 1922) were abundant and exclusive in the preserved environment, showing themselves to be good environmental bioindicators.

Synanthropy and ecological aspects of Calliphoridae and Mesembrinellidae (Diptera: Oestroidea) in three ecological areas in Rio de Janeiro State, Brazil

The determination of the synanthropic index is essential to evaluate the degree of association between species, such as diptera and man, based solely on their degree of preference for urban areas. This research aimed to study the synanthropic behavior of Calliphoridae and Mesembrinellidae flies in Rio de Janeiro, Brazil. The experiment was conducted between 2021 and 2022 in three areas, where four traps containing 300 g of fresh liver or with 48 h of putrefaction were installed, remaining exposed for 48 h; after collection the dipterans were sacrificed and taxonomically identified. A total of 2,826 dipterans were collected, represented by nine species of Calliphoridae (89.24%) and ten of Mesembrinellidae (10.76%), with the first record of Mesembrinella currani in this biome. The Kruskal-Wallis test showed that the abundance of individuals did not differ among the three analyzed environments. The Mesembrinellidae family was exclusively asynanthrope, along with two species of Calliphoridae: Hemilucilia benoisti (Séguy 1925) and Paralucilia nigrofacialis (Mello 1969) which were exclusive of the forest area, while Calliphoridae had varied synanthropy. Lucilia eximia (Wiedemann 1819) alone represented 57.18% of the total sampled, being the most abundant in all environments except the urban area where Hemilucilia segmentaria (Fabricius 1805) totaled 55.73%. No species were exclusive to the urban area, however Cochliomyia hominivorax (Coquerel 1858) and Lucilia cuprina (Wiedemann 1830) were exclusive to the rural area. The most synanthropic species were Chrysomya megacephala (Fabricius 1794) and Chrysomya albiceps (Wiedemann 1819).

Diversity of Necrophagous Flies (Diptera: Calliphoridae, Mesembrinellidae, and Sarcophagidae) in Anthropogenic and Preserved Environments of Five Different Phytophysiognomies in Northeastern Brazil

The present study investigated the potential association between the richness and abundance of species of the dipteran families Calliphoridae, Mesembrinellidae, and Sarcophagidae in anthropogenic and preserved environments of five phytophysiognomies (Cerrado, Amazon forest, Palm forest, marshland, and mangrove) that occur throughout the state of Maranhão, in northeastern Brazil. We sampled 90 sites (45 preserved and 45 anthropogenic areas) where we collected 26,036 specimens: 15,023 calliphorids (11 species), 231 mesembrinellids (one species), and 10,772 sarcophagids (52 species). Four environmental factors, canopy openness, temperature, leaf litter depth, and vegetation height, contributed most to the separation of preserved and anthropogenic sites in all five phytophysiognomies. Leaf litter depth was positively associated with the species richness of the calliphorids and mesembrinellids (C+ M group), while tree/shrub density, vegetation height, and temperature were associated negatively with the richness of the sarcophagids. Tree/shrub density and vegetation height were also associated negatively with abundance in both C+M and sarcophagid species. Overall, then, the structural characteristics of the environment affected the species richness and abundance, and deforestation may favor certain synanthropic species, leading to a decrease in the richness and abundance of the species that are adapted to preserved environments.

Population Fluctuation, Influence of Abiotic Factors and the Height of Traps on the Abundance and Richness of Calliphoridae and Mesembrinellidae

Calliphoridae and Mesembrinellidae are relevant to environmental conservation, public health, and forensic entomology. Researches regarding the flight behavior and the influence of abiotic factors on these insects may assist the application of entomology sciences. This study aimed to analyze the population fluctuation of Calliphoridae and Mesembrinellidae, verifying the influence of environmental factors, trap height, and the anthropic effect in the Itaipu-Piratininga lagoon complex, Niterói (RJ). The collections were carried out monthly from September 2015 to August 2016, with fish bait (sardines) exposed for 48 h, totaling six traps, installed in three physiognomies (mangrove, ombrophilous forest, and restinga) at 1.5 and 2.5 m from the ground. Nine thousand seven hundred seventy-three individuals were captured, comprising two families, five genera and 11 species. Chrysomya megacephala (Fabricius, 1794) (Diptera: Calliphoridae) was the predominant species and Mesembrinella bellardiana (Aldrich, 1922) (Diptera: Mesembrinellidae) the least representative, indicating the low preservation level of this ecosystem. There was a weak, positive correlation between abundance of Chloroprocta idioidea (Robineau Desvoidy, 1830) (Diptera: Calliphoridae), Ch. megacephala, Chrysomya putoria (Wiedemann, 1818) (Diptera: Calliphoridae), and Lucilia cuprina (Wiedemann, 1830) (Diptera: Calliphoridae) with the temperature, as well as between the abundance of C. idioidea and Chrysomya albiceps (Wiedemann, 1819) (Diptera: Calliphoridae) with precipitation; however, there was no correlation between abundance and relative humidity. No significant influence of the trap height was observed. We stated a high influence of anthropic effects on the restinga and mangrove physiognomies, while the forest physiognomy still retains its preserved characteristics, with the dominance of forestall species.

Diversity of Calliphoridae and Mesembrinellidae (Diptera: Oestroidea) in a Mangrove, Restinga, and Forest Landscapes From a Lagoon Complex on an Atlantic Forest Coastline (Rio de Janeiro, Brazil)

Diptera Mesembrinellidae present great ecological importance as potential bioindicators and Calliphoridae stand out for their medical-sanitary importance as potential vectors of pathogens and causes of human and animal diseases such as myiasis. They beneficially aid in elucidating crimes in forensic entomology, contributing to determine the postmortem interval (PMI) and assisting in the healing process of necrotic wounds in larval therapy. This study aimed to inventory the Calliphoridae and Mesembrinellidae fauna in order to evaluate structural parameters and to apply faunal indexes in catching species in the Itaipu-Piratininga lagoon complex, in Niterói (Rio de Janeiro), Brazil. The collections were carried out monthly from September 2015 to August 2016 with fish bait (sardines) exposed for 48 h, totaling six traps installed in three physiognomies (mangrove, ombrophilous forest, and restinga). In total, 9,773 individuals were captured, divided into two families, five genera, and 11 species. Chrysomya megacephala (Fabricius, 1794) was the predominant species, while Mesembrinella bellardiana (Aldrich, 1922) was the least representative species, indicating the preservation level of this ecosystem. Ombrophilous forest was the physiognomy with greater diversity and restinga was the physiognomy with greater species dominance. The similarity index indicated greater similarity among the mangrove and restinga populations.

A review on the occurrence of Cochliomyia hominivorax (Diptera: Calliphoridae) in Brazil

Cochliomyia hominivorax (Coquerel, 1858), the New World screwworm, causes primary myiasis in wild and domestic animals in tropical and subtropical regions of Brazil. Although this species is considered to occur throughout the country, organized information about its recorded distribution has not been available until now. This article aimed to provide a comprehensive review of the historical and current data published on both immature (myiasis) and adult stages of C. hominivorax in Brazil. A total of 174 articles were found; of these, 141 articles reported myiasis cases in cattle (146 records), humans (68 records), and other mammalian hosts (40 records), and captures of adult flies were reported in 33 articles. C. hominivorax is widespread in Brazil, having been recorded in 208 municipalities in all major biomes of the country.

First molecular phylogeny of Paralucilia Brauer & Bergenstamm, 1891 (Insecta, Diptera, Calliphoridae): A preliminary approach

Paralucilia Brauer & Bergenstamm, 1891 (Diptera, Oestroidea, Calliphoridae) is a small genus of blowflies restricted to the Neotropical region, which is commonly reported on decaying corpses and vertebrate carcasses. The number of species currently assigned to this genus and their denominations are contentious, with either three or five species recognized by different authors. This taxonomic instability results in a lack of consensus in species determination, making it impossible to compare results from different studies as well as to elaborate confident taxonomic keys. In order to solve some of the most commonly reported taxonomic conflicts within this genus, to the best of our knowledge, this study presents the first phylogenetic hypothesis for the relationships among Paralucilia species, based on molecular analysis of the COI, ITS2, 28S, and 16S genes. Maximum parsimony, maximum likelihood, and Bayesian inference analyses were used for phylogenetic reconstruction and divergence time estimation analyses. Intra- and interspecific genetic distances were calculated among species using the COI dataset. The results showed that at least three of the five currently accepted species are well defined: P. fulvinota, P. pseudolyrcea, and P. paraensis, however, a significant level of intraspecific variation was observed in P. fulvinota. These findings will assist future revisions of the description, classification, and distribution of species of Paralucilia, as well as in the elaboration of taxonomic keys. Additionally, we show that it is possible to clarify the evolutionary history of this Neotropical genus using supplementary evidence such as morphology and molecular data.

Faunistic Analysis of the Families Calliphoridae and Mesembrinellidae (Diptera) at Jardim Botânico do Rio de Janeiro, Brazil

Flies of the family Calliphoridae play a variety of ecological roles. They carry various pathogens and cause myiasis in humans and livestock, but they are useful to forensic entomology and in larval therapy. Mesembrinellidae flies, formerly classified in the family Calliphoridae, are good bioindicators of human interference in natural environments. In this study, we carried out an inventory of the Calliphoridae and Mesembrinellidae at four collecting sites within the Jardim Botânico do Rio de Janeiro. Eight traps were set, four in the arboretum (sites A and B), where the public is allowed to visit, and four at an Atlantic Forest fragment (sites C and D), open only to researchers. From July 2014 to June 2015, a total of 35,890 calliphorid flies were captured in 10 species and 145 Mesembrinellidea in 3. The greatest number of flies was found at site A and diversity was higher at site C. Chrysomya megacephala (Wiedemann) (Diptera: Calliphoridae) was the most prevalent species, being present at all sites. Mesembrinella bellardiana (Aldrich) (Diptera: Mesembrinellidae), Laneella nigripes (Guimarães) (Diptera: Mesembrinellidae), and Huascaromusca purpurata (Aldrich) (Diptera: Mesembrinellidae) were present at sites C and D, which indicates a preservation of the area because they are asynanthropic species. There were significant differences between sites A and D and sites B and D.

Dipterofauna Associated With Rat Carcasses in the Atlantic Forest, Southeastern Brazil

Each biome has its own fauna and intrinsic local conditions that determine the succession patterns of insects on carcasses. For this reason, regional studies are very important to forensics. This study deals with the flies that visit carcasses of Rattus rattus (L., 1758) in the Atlantic Forest remnant of Floresta da Tijuca, Rio de Janeiro, Brazil. We compare the diversity and relative abundance of fly families and species throughout the four seasons of the year and test for correlations between certain environmental variables and fly richness. In each of the four seasons, we exposed the carcasses of three rats. The carcasses were put in traps that were installed on the ground, separated by 100 m. The flies were collected from the carcasses on a daily basis, and were taken to the laboratory and kept in a climate chamber (28 °C day and 26 °C night). A total of 5,537 flies were captured, identified into 12 families: Calliphoridae (4,884 specimens), followed by Sarcophagidae, Micropezidae, Fannidae, Muscidae, Phoridae, and Neridae. Canonical correspondence and redundancy analyses of the environmental variables indicated no relationship between the seasons and fly abundance. Carcass decomposition lasted longer in the winter (12 d) than in the summer (8 d). The Margalef richness index indicated higher richness in the spring and winter, and lower richness in the summer. The Shannon-Wiener index and Simpson dominance indicated greater diversity in the spring. Diptera colonized all stages of decomposition. The families Calliphoridae and Sarcophagidae were more prevalent during the Fermentation stage. Our data have important implications for forensic entomology.