Examination of Nocturnal Oviposition by Chrysomya putoria (Diptera: Calliphoridae) in Brazil.

This is the first study in Brazil that monitored the nocturnal oviposition behavior of Chrysomya putoria, a species of forensic importance, in order to verify if individuals of this species oviposit at night. Groups of 10 flies (5 male and 5 female) distributed in ten cages were kept in a fume hood and submitted to total darkness or exposed to artificial light for eleven consecutive hours through four experimental conditions in the laboratory. Two verifications were made to see if the females oviposited in the offered substrate of about 20 g of chicken gizzard per cage. Verification 1 occurred at 09:00 pm in the evening experiments and at 09:00 am in the daytime experiments. Verification 2 occurred at 05:00 am in the night experiments and at 05:00 pm in the daytime experiments. Each experiment lasted 5 d. C. putoria laid eggs at night (with or without light) and the quantity of eggs was significantly similar to those produced during the day under natural light or in total darkness. Only the amount of eggs produced during the day in the absence of light was considerably greater than in the typical daytime period. The females oviposited in greater quantity in the nights when the average temperature was between 23 and 24.8°C and relative humidity above 81%. Ovipositions only occurred at temperatures above 21°C and humidity above 56% during the day. Finally, it is necessary that more evaluations on the effect of variables on blowfly behavior are performed to better understand nocturnal oviposition.

The Nocturnal Ovipositon Behavior of Chrysomya megacephala (Diptera: Calliphoridae) in Brazil and Its Forensic Implications.

Chrysomya megacephala (Fab. 1794) (Diptera: Calliphoridae) is a very important species for forensic entomology, mainly contributing estimations of the postmortem interval (PMI) in judicial investigations. There are some doubts about the nocturnal oviposition of these flies, which could lead to errors in the PMI calculation. This study aimed to monitor the nocturnal oviposition behavior of this species through four experimental conditions carried out in laboratory. Ten cages, each containing five males and females (n = 100), were kept in a fume hood and subjected to total darkness or to artificial light for 11 consecutive hours. Two verifications were performed to determine whether the females deposited eggs on the substrate of ~20 g of chicken gizzards per cage. The first verification occurred at 9:00 pm in nocturnal experiments and at 09:00 am in diurnal experiments. The second verification occurred at 05:00 am in nocturnal experiments and at 05:00 pm in diurnal experiments. Each experiment lasted 5 d. Chrysomya megacephala deposited eggs at night under artificial light and in total darkness, but the amount of eggs was significantly lower when compared with the daytime experiments in dark conditions and under natural light. Oviposition occurred when the average temperature was around 25°C (± 2°C) and relative humidity around 73% (± 6%). Night oviposition is a possibility which should not be ruled out. Thus, future experiments are recommended.

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.

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.