Environmental necrophagous fauna selection in a funerary hypogeal context: The putridarium of the Franciscan monastery of Azzio (northern Italy)

Insects play a fundamental role in the removal and recycling of the organic matter from human cadavers and animal carcasses. Several factors can affect both the cadaver decomposition and colonisation by insects and other animals. Accessibility to the body is one of these factors. The archaeological, anthropological and entomological investigations conducted inside the Crypt of the Franciscan Monastery in Azzio (Varese, northern Italy) allowed the reconstitution of the funerary practices used by a Franciscan community between the 17th and 18th centuries and provides a good example of necrophagous entomo-fauna selection. Human remains were found in the putridarium chamber, a semicircular room with sixteen narrow and semicircular niches, where bodies were located until the complete decomposition of the soft tissues. Numerous puparia were collected from the bones, the clothes and the niche walls. The majority belonged to Hydrotaea capensis (Diptera: Muscidae) and a few puparia of scuttle flies in the family Phoridae were detected among the studied material. Fragments of beetles in the families Staphylinidae and Cryptophagidae were also sampled. The entomological findings clearly support the hypothesis that the bodies were quickly transferred into the crypt after death and that the specific hypogeal (subterranean) environment selected the entomofauna community composition. The observations here reported with similar entomological findings cited in the literature support the hypothesis of a specific selectivity on insects' community by underground environments (e.g. graves, crypts). This conclusion can be applied to outline a common pattern in archaeological contexts and in indoor forensic cases.