The Effect of Suitcase Concealment on Insect Colonization: A Pilot Study in Western Australia
Received Date: March 11, 2019; Published Date: April 09, 2019
Decomposition is a complex and continuous process that involves the breakdown of soft tissues following a death event. This is often mediated by the action of micro- and macro-fauna, especially necrophagous insects belonging to the Orders Diptera and Coleoptera. Access to the cadaver is a major prerequisite for decomposition to proceed. However, a cadaver maybe concealed to avoid an easy discovery by the authorities. The present field study investigated the decomposition process of a carcass placed in a suitcase in Western Australia. A total of six pig carcasses (Sus scrofa L.) were used as a substitute for human cadavers. Five pigs were singularly placed in identical zip suitcases made of fabric and a sixth pig being fully exposed (control pig). As expected, the study showed that the rate of decomposition differed between the control pig and concealed pigs. The rate of decomposition of the control pig followed the typical pattern, in terms of stages of decomposition, and revealed the insect species involved in the process. Pigs inside the suitcases exhibited the characteristics of wet decomposition. This occurred despite no significant differences between the ambient temperature and the temperature inside the suitcases. However, the relative humidity inside of the suitcases was found to be statistically different and the pattern of insect succession varied between the concealed carcasses and the control pig. Carcass attendance by blow flies at the control occurred within minutes of positioning, and oviposition occurred within the first day. In contrast, blow flies were not observed visiting the suitcases until the next day, with oviposition on the external part of the suitcases not recorded until day 9 and inside the suitcases after day 14. The insect species also varied between those found inside the suitcases and on the control, with families Phoridae (scuttle flies) and Fanniidae (lesser house flies) being the most prevalent species inside the suitcases. This pilot study represents the first attempt in Australia to research decomposition of remains inside a suitcase.
Keywords: suitcase concealment; decomposition; Forensic entomology; Insect succession; Min PMI