Lasius emarginatus (Olivier, 1792) (Hymenoptera: Formicidae) confirmed as a British species [Update]

Posted by Mike Williams BSc (Hons) AIEEM on 17/01/2011

Lasius emarginatus (Olivier, 1792) (Hymenoptera: Formicidae) confirmed as a British species [Update]

Matthew N. Smith Michael A. Williams

In June 2008 Ecosulis discovered the first known colony of the ant Lasius emarginatus in mainland Britain. Ecosulis were undertaking an aquatic invertebrate survey of Regent’s Canal, and noticed the ants on a wall beside the canal. Only two single individuals of this species had been recorded from mainland Britain prior to this find, and no nest was found on either occasion.

Specimens were checked against the relevant literature and the collection at the Natural History Museum, London in order to confirm the identity. The site was revisited in August 2008 and the nest was still present.  A thorough search of the surrounding area for further nests proved negative. A single specimen of the Nationally Scarce ant Ponera coartata was found during this search as well as several common species of ants. 

Lasius emarginatus is found in continental Europe and the Channel Islands. How it arrived in Britain in open to debate. At the time it was found, the nest appeared to be rather small and is likely to have been established in 2007 or 2008. The species is widespread on the Channel Islands and it will be interesting to see if it can do as well on the UK mainland.

The full text of this article can be found in:

Smith, M. N. & Williams, M. A. (2008) Lasius emarginatus (Olivier, 1792) (Hymenoptera: Formicidae) confirmed as a British species. BWARS Newsletter Autumn 2008.

The nest was revisited in the summer of 2009 and was found to still be present. Approximately 80 worker ants were observed on the wall and on the towpath within 10 metres of the nest entrance, however no individuals were noted elsewhere along the towpath or in the local area.