New to Cheshire: Rare Solitary Bee Stelis phaeoptera

Log mound at Chester Zoo Nature Reserve (Chloe Aldridge)

On 25 May 2020, during a bee survey carried out as part of the biodiversity monitoring programme on the Nature Reserve at Chester Zoo (SJ4070), a single female Stelis phaeoptera was found investigating this log mound (right). One of the probable hosts of this kleptoparasitic bee, Osmia leaiana, was found on the site on the same day. The nectar sources used by this bee, such as knapweeds and other composites, and bird’s-foot trefoils are plentiful on the reserve.

S.phaeoptera is classed as Rare (RDB3) by Shirt (1987); and provisionally listed as Vulnerable (pRBD2) by Falk (1991). It is thought to have declined in the last century although there are several records from the past few years thinly scattered in a band from Wales across the Midlands and East Anglia. The largest cluster of recent UK 10 km squares for the species is not far away in Shropshire, but this appears to be the first time that this species has been recorded in Cheshire. This record also marks a new northern UK range limit for according to the BWARS distribution map (link below), NBN Atlas, and iRecord. The identification was confirmed from images of the specimen by Steven Falk.

Stelis phaeoptera under the microscope (Chloe Aldridge)













References and more information

BWARS: Stelis phaeoptera, species info sheet at:

S.Falk: Field Guide to the Bees of Great Britain and Ireland.

Chester Zoo Nature Reserve:


NBN Atlas page for Stelis phaeoptera: