• Decomposed liver has a significantly adverse affect on the development rate of the blowfly Calliphora vicina

      Richards, CS; Rowlinson, CC; Cuttiford, Lue; Grimsley, R; Hall, MJR (Springer Science and Business Media LLC, 2012-04-26)
      The development rate of immature Calliphora vicina reared on decomposed liver was significantly slower, by as much as 30 h (55.4 % of total development time) for mid-sized larvae, and 71 h (35.0 %) and 58 h (14.6 %) if using times to the onset of pupariation and eclosion, respectively, than those of immatures that developed on fresh whole pig's liver. Development rates of larvae reared on decomposed liver were also slower than those of larvae reared on minced pig's liver and frozen/thawed pig's liver. These results suggest that any estimate of minimum post-mortem interval may result in an over estimate if the blowflies used were developing on an already decomposed body.
    • Effects of storage temperature on the change in size of Calliphora vicina larvae during preservation in 80% ethanol

      Richards, CS; Rowlinson, CC; Hall, MJR (Springer Science and Business Media LLC, 2012-03-08)
      The size of immature blowflies is a common measure to estimate the minimum time between death and the discovery of a corpse, also known as the minimum post-mortem interval. This paper investigates the effects of preservation, in 80% ethanol, on the length and weight of first instar, second instar, feeding third instar, and post-feeding third instar Calliphora vicina larvae, at three different storage temperatures. For each larval stage, the length of larvae was recorded after 0 h, 3 h, 6 h, 9 h, 12 h, 24 h, 72 h, 7 days, 14 days, 30 days, 91 days, 182 days, 273 days, and 365 days of storage in 80% ethanol, at −25°C, 6°C and 24°C. Storage temperature had no statistically significant effect on the change in larval length and weight for all larval stages, but larval length and weight were significantly affected by the duration of preservation for first, second, and feeding third instar larvae, but not for post-feeding larvae. Generally, first and second instar larvae reduced in size over time, while feeding third instar larvae increased slightly in size, and post-feeding larvae did not change in size over time. The length of blowfly larvae preserved in 80% ethanol is not affected by constant storage temperatures between −25°C and +24°C, but we recommend that forensic entomologists should use the models provided to correct for changes in larval length that do become apparent over time.
    • Pigs vs people: the use of pigs as analogues for humans in forensic entomology and taphonomy research

      Matuszewski, S; Hall, MJR; Moreau, G; Schoenly, KG; Tarone, AM; Villet, MH (Springer Science and Business Media LLC, 2019-06-17)
      Most studies of decomposition in forensic entomology and taphonomy have used non-human cadavers. Following the recommendation of using domestic pig cadavers as analogues for humans in forensic entomology in the 1980s, pigs became the most frequently used model cadavers in forensic sciences. They have shaped our understanding of how large vertebrate cadavers decompose in, for example, various environments, seasons and after various ante- or postmortem cadaver modifications. They have also been used to demonstrate the feasibility of several new or well-established forensic techniques. The advent of outdoor human taphonomy facilities enabled experimental comparisons of decomposition between pig and human cadavers. Recent comparisons challenged the pig-as-analogue claim in entomology and taphonomy research. In this review, we discuss in a broad methodological context the advantages and disadvantages of pig and human cadavers for forensic research and rebut the critique of pigs as analogues for humans. We conclude that experiments using human cadaver analogues (i.e. pig carcasses) are easier to replicate and more practical for controlling confounding factors than studies based solely on humans and, therefore, are likely to remain our primary epistemic source of forensic knowledge for the immediate future. We supplement these considerations with new guidelines for model cadaver choice in forensic science research.