A preliminary investigation of insect colonisation and succession on remains in New Zealand

A preliminary, systematic field study on the process of decomposition and associated insects was conducted, for the first time, in New Zealand. Using pig carcasses as an animal model for human decomposition, insect colonisation and succession was monitored in three different habitats in the Auckland region where remains are likely to be found. A significant difference in the rates of decomposition was found among the three different habitats of an open field, coastal sand dune area and native bush during the autumn/winter season. The primary colonisers of all carcasses were Calliphora stygia Fabricius (Calliphoridae), Chrysomya rufifacies Macquart (Calliphoridae) and Hydrotaea rostrata Robineau-Desvoidy (Muscidae). Two species were identified as possible representatives of the habitats in which they were found; Fannia sp. (Fanniidae) in the open field habitat and Calliphora hilli Patton (Calliphoridae) in the native bush habitat. Also identified was Sylvicola sp. (Anisopodidae) as a possible indicator of damp habitats as well as a likely indicator of a longer postmortem interval. This preliminary investigation presents a broad outline of the insects associated with remains and the order in which they appear in the Auckland region.