A mathematical model applied for assisting the estimation of PMI in a case of forensic importance. First record of Conicera similis (Diptera: Phoridae) in a corpse

We present a forensic case associated with skeletonized human remains found inside a cistern in a coastal town located in the eastern Iberian Peninsula (Valencian Regional Government, Spain). In order to analyse the particular environmental conditions that occurred during oviposition and development of the collected insects, estimated temperatures at the crime scene were calculated by a predictive mathematical model. This model analyses the correlation between the variability of the internal temperature depending on the variability of the external ones. The amplitude of the temperature oscillations inside the tank and the containment of the enclosure is reduced by the presence of water. Such variation occurred within about 2 h due to the time required for heat exchange. The differential equations employed to model differences between outdoor and indoor temperatures were an essential tool which let us estimate the post-mortem interval (PMI) that was carried out by the study of the insect succession and the development time of the collected Diptera specimens under the adjusted temperatures. The presence of live larvae and pupae of Sarcophagidae and empty pupae of Calliphoridae, Sarcophagidae, Fanniidae, Muscidae, Phoridae and Piophilidae and the decomposition stage suggested the possibility that the remains were in the tank at least a year. We highlight the absence of Calliphora and Lucilia spp., and the first occurrence of the phorid Conicera similis in a human cadaver among the entomological evidence. R.L. and J.M.G.V. are thankful for support from MEC of Spain [Grant No. CTQ 2010-19232]. This study was supported by a grant for studies of Phoridae from the Balfour-Browne Trust Fund (University of Cambridge) and Calliphoridae and Sarcophagidae studies by Generalitat Valenciana [GV/2011/039] and Alicante University projects [GRE09-27].