Initial study of arthropod succession on pig carrion in a central European urban habitat

We conducted a carrion succession study within a restricted urban backyard in the city of Vienna, Austria (16 degrees 22'E, 48 degrees 12'N) from May to November 2001 to analyze sequence and composition of the local carrion visiting fauna. Two medium sized clothed domestic pig carcasses (Sus scrofa Linnaeus), were used as surrogate human models. In total, 42 arthropod species from the families Calliphoridae, Sarcophagidae, Sepsidae, Piophilidae, Muscidae, Fanniidae, Sphaeroceridae, Phoridae, Drosophilidae, Anthomyiidae, and Lauxaniidae (Diptera), Formicidae, Braconidae, Pteromalidae, and Vespidae (Hymenoptera), Silphidae, Staphylinidae, Histeridae, Cleridae, and Dermestidae (Coleoptera), as well as species from the orders Isopoda and Acari were collected during the decomposition of these carcasses. A significant feature in this study was the high abundance of Calliphora vomitoria (L.) and Chrysomya albiceps (Wiedemann). In the experiment conducted May to June, larvae and adults of C. vomitoria outnumbered all other blow fly species, followed by Protophormia terraenovae (Robineau-Desvoidy), C. vicina Robineau-Desvoidy, and Lucilia sericata (Meigen). C. vomitoria is generally considered to be rural in distribution, where it prefers shaded locations. The presence of this species in rural as well as in urban habitats in Austria precludes this species as biogeographic indicator. In the study beginning in August large numbers of female adults of the nonindigeous blow fly C. albiceps began oviposition at day 3 after placement of the cadaver. The predatory second and third instars of C. albiceps larvae subsequently almost monopolized the cadaver. C. albiceps is generally described as tropical and subtropical species. The observed northward expansion of its range beyond southern Europe obviously decreases the value of C. albiceps in estimating place of death, in that it is no longer exclusive to southern regions. Our results clearly show, that caution must be used when drawing conclusions from succession data generated in different geographic areas. Moreover, this study demonstrates, that arthropod mediated decomposition of a 44 kg exposed pig carcass in a central European urban habitat can be completed within 3 wk.