A Framework of Morphological and Molecular Methods for the Analysis and Interpretation of Entomological Remains from Archaeological and Forensic Contexts

Insects and their fragments are often recovered from crime scenes and archaeological deposits as essential evidence in support of forensic and environmental archaeological investigations. Insects colonise the most diverse natural and anthropic environments, however different taxa show different ecological preferences and their development and phenology are species-specific and temperature dependent. Therefore, species identification is of primary importance to make any interpretation of the case. Today, insects identification can be achieved using two different approaches: 1) the morphological analysis of diagnostic features is currently well-established, irreplaceable and traditionally widely used method; 2) on the other hand, the DNA-based identification method has been integrated more recently (second half of 1980s) as a consequence of the rapid advance of molecular biology techniques.

The main objective of this thesis is to provide an accurate framework of how to proceed to analyse entomological remains collected from contexts where conservation status is not optimal. A strong focus is directed on Diptera, using both approaches and providing a pragmatic and critic workflow of analysis for reliable interpretative purposes. In particular, the lack of descriptions of immature stages of poorly studied species is considered and investigated.

To achieve this, three macro-projects concerning either archaeoentomological or forensic entomological investigations are presented through the analysis of two case-studies, respectively.

The outcomes of the whole research include:
i) an original contribution to molecular archaeology research, through the ex novo design of a DNA-based workflow applied to Diptera puparia;
ii) an innovative contribution to the environmental archaeology research belonging to the Italian heritage, through the analysis of mineralised findings recovered from a Sardinian medieval urban well, and found in association to human remains within a Roman grave;
iii) an essential contribution to forensic entomology, through the generation of new morphological data of immature stages of Physiphora alceae (Diptera: Ulidiidae) and through the comparative descriptions of puparia of ten species of Piophilidae, along with the design of a dichotomy key.

Although the results are overall promising, further research is needed within molecular archaeology field applied on Diptera puparia. An improved workflow which meets all the essential authenticity criteria will be a great achievement and will provide an extra tool of analysis for archaeological records. The great potential of the archaeoentomological investigations in deriving interpretations of the human past and practices has been demonstrated not only through the identification of taxa but also through the analysis of taphonomic processes involved in their preservation. Finally, an integrated taxonomy-DNA based approach is beneficial, whether applicable, to strengthen the accuracy of the identifications; however, a continuous research is necessary to generate new data especially of unexplored and poorly studied taxa of forensic interest.