Effects of concealment of porcine remains on colonization by necrophilous insects

The decomposition and subsequent colonization of pig carrion (Sus scrofa (L.)) placed in concealed and open environments, by necrophagous insects was studied during the spring, summer, and fall in Raleigh, North Carolina. Remains were concealed in three manners, ranging from minimal to well concealed, in simulated attics. Concealment had a significant effect on the insect community colonizing the remains. Although calliphorids and other fly species colonized remains located indoors, the beetles Necrobia rufipes (DeGeer) and Dermestes maculatus (DeGeer) were the only species indicative of remains located indoors. In contrast, numerous fly species, beetle species, and an ant species, were species indicative of remains located outdoors. Season also significantly affected the insect species colonizing decomposing remains, particularly blow flies. Lucilia illustris was indicative of the spring, Cochliomyia macellaria (F.) and Chrysomya rufifacies (Macquart) were indicative of the summer, and Calliphora vicina (Robineau-Desvoidy) and Calliphora vomitoria (L.) were indicative of the fall. Additionally, across all seasons, concealment of remains delayed colonization by 35-768 hours, depending on the degree of concealment. These differences between the insect communities across seasons and concealment treatments, and the effects of concealment on colonization indicate that such information is important and should to be considered when analyzing evidence for criminal investigations.