Northern Ireland's Priority Species

Sphecodes pellucidus – a solitary bee

 
Sphecodes pellucidus

Sphecodes pellucidus Smith F.
Family: Halictidae

This solitary bee is a nest parasite of another solitary bee species, Andrena barbilabris. Females of Sphecodes pellucidus lay their eggs in the provisioned cells of the host nest. The species is only known from Murlough National Nature Reserve.

In brief

  • Recorded twice from Murlough National Nature Reserve, Dundrum in County Down. The last record was in 1984

  • Sphecodes pellucidus has not been recorded at any other Irish site

  • The host species Andrena barbilabris is found in sandy coastal areas, especially on the east coast. It nests in burrows in the ground

  • The Murlough specimens of S. pellucidus were taken in May and June. Adults should also be on the wing later in the year

  • The trends in the Irish population are unknown.

Species description
The bee is small and mainly hairless. The thorax and head are dark and the abdomen is mainly blood red.

Life cycle
The Sphecodes bees are parasitic on the solitary burrow-nesting bees of the genus Andrena, Lasioglossum and Halictus. Female Sphecodes lay their eggs in the provisioned nests of their hosts, eating the host egg in the process. The larvae feed on the food store intended for the host larva. S. pellucidus is a parasite of A. barbilabris, a spring- and early summer-flying solitary bee.

Similar species
There are many species of solitary bee in Ireland and their identification is a specialist activity. There are eight representatives of the genus Sphecodes in Ireland. The species are all very alike and their field identification is not possible.

How to see this species
The most likely place to encounter Sphecodes bees are at the nest aggregations of their hosts. The host of this species is Andrena barbilabris which nests in aggregations in sandy soil in spring and early summer. Adult Sphecodes can also be seen feeding on flowers. S. pellucidus adults particularly favour species of composite. The species is only known from Murlough National Nature Reserve.

Current status
It has been recorded twice from Murlough National Nature Reserve in 1973 and 1984. These remain the only Irish records, as no specimens were found during a recent survey of Irish bees to assess their status. However, there is no reason to suppose the species is lost.

Why is this species a priority in Northern Ireland?

  • The species is rare and the Irish population is restricted to Northern Ireland.

Threats/Causes of decline
The trends in the Irish population are unknown. As a parasitic species, the population of this species could be negatively impacted by a decline in the population of its host, A. barbilabris. It however remains a relatively common species along the east coast of Ireland as far north as Co. Down. Colonies could be lost through development and loss of semi-natural habitat.

Conservation of this species

Current action

  • Murlough National Nature Reserve is a SAC and ASSI

  • It is managed by the National Trust.

Proposed objectives/actions

  • Locate nest aggregations of host and survey for presence of S. pellucidus

  • Survey suitable sites to locate extant populations and, if any are found, ensure the population is maintained.

What you can do
If you see the species, report any sightings to CEDaR, National Museums Northern Ireland, 153 Bangor Road, Cultra, Co. Down, BT18 0EU, Tel: 028 9039 5256, cedar.info [at] nmni.com or to the Bees, Wasps and Ants Recording Scheme (BWARS) who organise the recording of solitary bees in Britain and Ireland.

Further information

Links
http://www.bwars.com

http://www.ehsni.gov.uk/area_interest_sitesview?SiteNo=ASSI089

The National Trust

Literature
Nelson, B., Ronayne, C., Nash, R. and O'Connor, J.P. (2001). Additions and changes to the Irish aculeate Hymenoptera checklist. Irish Naturalistsí Journal 26: 453-459.

Text written by:
Dr Brian Nelson, Curator of Freshwater Invertebrates, Ulster Museum