Diversity of Diptera species associated with pig carcasses in a Brazilian city exposed to high rates of homicide

Abstract

Cities in northeastern Brazil experience extreme rates of unsolved homicides, a situation that stimulates innovative procedures in the police work, such as forensic entomology. We surveyed necrophagous insects associated with carrion in a city exposed to high rates of homicides in Northeastern Brazil. The experiments were carried out in a rainforest fragment located in Recife, State of Pernambuco. Two pig carcasses were used as models, one in the dry and the other in the rainy season. The collection of adults was performed daily until the complete skeletonization of the carcasses. At least 32 Diptera species from the families Calliphoridae, Muscidae, Sarcophagidae, Fanniidae, Phoridae, Anthomyiidae, Piophilidae, and Stratiomyidae were registered, some of which have been previously documented on cadavers. A high richness of Diptera species was registered in all stages of decomposition. A strong overlap in the occurrence of most species was observed, which invalidates a defined entomological succession on the carcasses. Two species stood out in terms of abundance: Ophyra chalcogaster (Muscidae) and Chrysomya albiceps (Calliphoridae). The ubiquity of Hemilucilia semidiaphana (Calliphoridae) seems to confirm its preference for forest fragments exposed to low anthropogenic action. Our data contribute to expand the knowledge on the geographical distribution of forensically relevant species in the region and confirm the rapid dissemination of invasive Chrysomya species in forested areas.

Ecological succession of blow flies (Diptera: Calliphoridae) in the decomposition of pig carcasses in Cerrado areas of Brazil

“…Diptera are the most common and abundant insects on carcasses, making them crucial in forensic investigations (Souza and Linhares 1997, Moretti et al 2008, Rosa et al 2011, Scaglia 2014, Faria et al 2018, Ramos-Pastrana et al 2018, Meira et al 2020, Vairo and Moura 2021, Silva et al 2023). Calliphoridae, or blow flies, is one of the most studied Diptera families under the forensic aspect, because they are pioneers and abundant in carcasses in the decomposition stage, which are used as a food source, copulation site, and/or substrate for the development of their immature stages (Wolff et al 2001, Amendt et al 2010, Oliveira-Costa 2011, Silva et al 2014, Ramos-Pastrana et al 2018, Meira et al 2020, Cruz et al 2021).…”

“…Even though Calliphoridae species can be found at all stages of carcass decomposition, they are often associated with specific stages (Byrd and Castner 2001, Pérez et al 2005, Ramos-Pastrana et al 2018, Meira et al 2020, Cruz et al 2021). Therefore, identifying the occurrence of each species by stage is an essential source of information in calculating the post-mortem interval (PMI) of human corpses, mainly when they are in an advanced condition of decomposition and traditional approaches are ineffective (Catts and Haskell 1991, Byrd and Castner 2001, Oliveira-Costa 2011, Meira et al 2020).…”

First record of the Ravinia almeidai (Lopes, 1946) (Diptera: Sarcophagidae: Sarcophaginae) to the state of Bahia, Brazil

“…Currently, in Brazil, studies with sarcophagids are mostly centered on the north, south and southeast regions (Pape 1996;Carvalho et al 2002) and, for this reason, little is known about the fauna of other regions, especially the northeast region, except for the Pernambuco state (e.g. Oliveira & Vasconcelos 2010;Oliveira & Vasconcelos 2018;Barbosa et al 2017Barbosa et al , 2020Barbosa et al , 2021Carmo et al 2021;Cruz et al 2021), where knowledge is incipient and limited. The main factors that hinder the expansion of knowledge for the region are the taxonomic difficulties in recognizing these dipterans (since, for many species, only males are safely identified by the terminalia morphology), the lack of adequate literature and, above all, the acting of few taxonomists, which often prevents and discourages research with sarcophagids (Mello-Patiu et al 2014).…”