Effect of freezing on the initial colonization of the carcass with necrophagous organisms

This study was aimed to determine whether freezing of cadaver prior to the free exposure affects the species composition and the rate of its initial colonization with necrophagous organisms. Two experiments were realized in Smečno town, the Central Bohemian Region of the Czech Republic, in which carcasses of domestic fowl (Gallus gallus f. domestica L.) weighing about 1.5 kg were obtained and treated the same way, only half of them were frozen before exposure in June and July 2013. Pre-frozen and fresh carcasses colonized the same kinds of blowflies (Diptera, Calliphoridae): Calliphora vicina Robineau-Desvoidy, 1830, Lucilia sericata (Meigen, 1826), Lucilia illustris (Meigen, 1826), Lucilia ampullacea Villeneuve, 1922, Phormia regina (Meigen, 1826), and Protophormia terraenovae (Robineau-Desvoidy, 1830). Percentage rate of each species was almost the same in both versions but we found differences in the total number of individuals (larvae) decomposing carcasses and differences in the process of decomposition of carcasses: fresh carcass decomposition was predominantly anaerobic (putrefaction) and started from the digestive system to the outside of the body (inside-out). Pre-frozen carcasses decomposed predominantly aerobic (decay) and started from the surface of body inwards (outside-in). Utilization of our results in forensic practice is discussed.