Estimation of post-mortem interval for a drowning case by using flies (Diptera) in Central-South China: Implications for forensic entomology

The area of forensic entomology has developed to become an increasingly important aspect of forensic science. Insect larvae and adult insects found on human corpses can provide crucial information for the post-mortem interval (PMI) estimation. In July 2010, a decomposing female corpse was found in Xiangjiang River of Changsha section. The main larvae found on the corpse were identified to be Boettcherisca peregrina (Robineau-Desvoidy) by morphologic observation and were then confirmed by mitochondrial DNA sequence. Based on the experimentally obtained entomological evidence, PMI of the female was concluded between 90 and 120 hours. However, eyewitness reports finally confirmed that the elapsed time since death were 128 hours. This case indicates that PMI estimation in terms of the period of insect activity (PIA) is very complicated and concern many factors such as insect species characteristics, weather and seasonality, geographic region. The interaction between forensic entomologists and pathologists in death cases where insects are associated with remains should be encouraged.