Development of synanthropic beetle faunas over the last 9000 years in the British Isles

The timing and mechanisms for the develpment of synanthropy for insects is under-explored worldwide; however, substantial archaeoentomological datasets are required to explore this issue in detail. In the British Isles, 50 years of research has generated such a dataset, which we have compiled for this paper. It consists of beetle (Coleoptera) faunas from 55 archaeological sites, comprising 85,829 individuals; out of which 22,670 individuals, representing 128 taxa, were classed as semi- or fully-synanthropic (human-dependent). The data were analysed in terms of presence/absence of different synanthropic taxa; as well as the relative proportions of a range of synanthropic ‘groupings’ for each archaeological period, type of deposit and type of archaeological site. We argue that there are distinct waves of the development or introduction of synanthropes in the British Isles. This initially consisted of a limited group of taxa, derived from the natural environment during the Mesolithic and Neolithic. A second wave of taxa associated with intensive stock raising, pasture and fodder production occurs in the Late Bronze Age/Iron Age. Finally, a range of strongly synanthropic species, including grain pests, were introduced into the British Isles by the Romans as a result of large-scale trade and the development of urban life. Further areas of research, particularly internationally, are outlined.