Dipteran succession on decomposing domestic pig carcasses in a rural area of southeastern Brazil

Abstract

Diptera plays a pivotal role in forensic investigations, particularly in estimating the post-mortem interval. This can be achieved by analyzing the succession patterns of species on decomposing bodies, which requires detailed knowledge of the local fauna. In rural areas of the Rio de Janeiro state, Brazil, forensic entomological succession remains understudied. This study aimed to evaluate the ecological succession of adult and immature dipterans on decomposing pig carcasses in rural areas of Seropédica municipality during dry and rainy seasons, through the threshold indicator taxa analysis (TITAN). For adult dipterans during the rainy season, we identified 25 ‘Z-’ taxa, with change points (cp) between days 4 and 14, while one ‘Z+’ taxon showed a cp at day 16. During the dry season, 22 ‘Z-’ taxa exhibited cp between days 4 and 1, and one ‘Z+’ taxon was identified on day 13. Among immature dipterans, we identified 3 ‘Z-’ taxa with cp between days 9 and 16, while 2 ‘Z+’ taxa showed cp. at days 5 and 21.5. Our findings provide valuable insights for forensic professionals by offering continuous ecological change point analysis, which help address the challenges of interpreting heterogeneous decomposition stages, which are often difficult to delineate in forensic casework.