A new British Bee at Radley

Stelis phaeoptera © Adrian Jones, BWARS

Article written by Ivan Wright

In June last year a new species of British bee, Stelis odontopyga, was found at the Radley Ash Disposal Site near Abingdon. The bee is a nest ‘cuckoo’ of the fairly common mason bee Osmia spinulosa, that nests in vacated snail shells and collects its pollen from composite flowers such as oxeye daisy and hawkbits. On continental Europe S. odontopyga uses various Apiaceae and Asteraceae flowers for nectar.

The S. odontopyga found at Radley, a lone female, was recorded by Ivan Wright during a commissioned survey of the old reclaimed gravel extraction pits east of Abingdon. When discoveries such as this occur, especially involving cavity nesting insects, there is always the possibility that they may have arrived in imported plant material, including timber. Consequently, once identified and found to be absent from the list of resident British species, nomination as a new British species can take some time to establish. However, in the case of the S. odontopyga at Radley, quite remarkably, a male of the same species was caught two days later – in Kent. Furthermore, when these records were announced to the Bees, Wasps and Ants Recording Society (BWARS), another Kent specimen was found in a BWARS members’ collection, misidentified from the previous year. On the basis of these records the species was declared new to Britain.

Bees of the genus Stelis are elusive and seem to occur in low numbers in the UK, and this is likely to be the same for S. odontopyga.  Its host, Osmia spinulosa, is widely distributed in southern England and so S. odontopyga may well show up again in Oxfordshire where there is a suitable flora and plenty of snails.

The article announcing the new British species, together with the details of identification, is available from Ivan Wright (irwright@shotover-wildlife.org.uk) or the British Journal of Entomology & Natural History, 2019, Volume 32, Part 1. The Radley Ash Disposal Site survey was commissioned by Abingdon Naturalists Society with the permission of access from Earth Trust, RWE Generation and H. Tuckwell & Sons Ltd.

Posted: November 11, 2019