There are 40 species on the main British List (Duff, 2008) plus a further 8 in the appendix of “non-established introductions”. 39 of the 40 are covered by Enid Peacock’s RES Handbook (Peacock, 1993), the missing species being Attagenus trifasciatus which was omitted “as it has not been recorded in Britain since 1839”. It’s a very good Handbook, covering larval identification as well as adults. It appears still to be available from RES here but they are unlikely to re-print once they’re out of stock, so who knows for how much longer it will be available.
Photographs of all the British species are online at Andreas Herrmann’s website: www.Dermestidae.com. There are whole-animal photographs as well as lots of photographs showing relevant identification characters such as antennal structure and abdominal sternites. I have linked the images of all of the 40 British species below.
Most of the 9 species of Anthrenus on the British list are rarely found and only as imports or indoors. By far the commonest British species in indoor situations is A. verbasci. Outdoors, I find A. verbasci and A. fuscus quite frequently. The patterns of scales seem to be too variable to provide reliable identification characters. Peacock’s (1993) keys rely on the numbers of antennal segments and other microscopic characters. A. verbasci can be identified by its 11-segmented antennae and the evenly convex (rather than emarginate) inner margins to its eyes.
Duff, A.G. (2008). Checklist of beetles of the British Isles. 2008 edition. Wells: A.G. Duff.
Peacock, E. (1993). Adults and larvae of hide, larder and carpet beetles and their relatives (Coleoptera: Dermestidae) and of derodontid beetles (Coleoptera: Derodontidae). Handbooks for the identification of British insects, vol. 5, part 3. London: Royal Entomological Society.