The 'Noble false widow' spider Steatoda nobilis is an emerging public health and ecological threat

Steatoda nobilis, the 'Noble false widow' spider, has undergone massive population growth in southern Britain and Ireland, at least since 1990. It is greatly under-recorded in Britain and possibly globally. Now often the dominant spider on and in buildings in the region, the species occurs on many items which increase a risk of bites to people - including household furniture, railings, handles, lighting and street furniture. There is a lack of awareness amongst the public, medics and arachnologists as to the likely bite rate and severity with this spider, and there is under-recording of bites. There is thus a possibility of bites being left without adequate rapid treatment and monitoring - with a low but non-trivial risk of necrosis or sepsis. A plausible incident of anaphylactic shock is identified, requiring professional confirmation and case study. Further study of bite significance is urgently required but a typically precautionary approach should be adopted in the interim. A lag of over a century between introduction and the species rapidly becoming common in Britain indicates the risk of complacency over invasive species. Local eradication will be very difficult, so education is required on identification and response to possible bites. The species may become a widespread public health concern and a global conservation problem - particularly on islands with endemic invertebrates. Arachnologists typically have a conflict of interest which may result in understatement of risks. Research priorities include: assays for venom cytotoxicity and microbial carriage; improved immunological and clinical surveillance for possible spider bites; and monitoring of the global distribution and ecological impacts. This paper aims to facilitate and stimulate inter-disciplinary knowledge exchange and gathering, to enable more appropriate and proportionate responses to bites, infestations and invasions. Version 4 of this preprint has been peer-reviewed and recommended by Peer Community In Zoology (https://doi.org/10.24072/pci.zool.100001)