21 June 2012
The Small Ranunculus has recolonised Britain thanks to brownfield sites.
This moth was once widespread in southern Britain (mainly South East England and East Anglia) but declined dramatically during the late 19th and early 20th centuries and was certainly extinct here by 1939. However, in recent years it has returned, recolonised Britain and is now increasingly widespread both within many of its old haunts and further afield.
Although the first modern sightings of Small Ranunculus were from gardens, all the records of caterpillars have come from brownfield sites. The first modern British record was from a Kent garden in 1997. The following year larvae were found at a disused quarry in Kent, and the moth is now widely established in South East England, including through London and Home Counties.
The first modern record in Wales was also an adult in a garden moth trap at Newport in 1999. Small Ranunculus larvae found in the town in 2003 on a dockside brownfield site and has subsequently been found on many brownfield sites in the area
The spread has continued with the North West of England proving another hotspot for Small Ranunculus sightings. First recorded in Cheshire in 2004 and in Lancs in 2005, there have been regular sightings of the moth since then and the species is clearly established in the area, although larvae have not yet been located.
In addition, there have been occasional sightings of adults in many other counties outside these areas in recent years e.g. Cambridgeshire, Northamptonshire, Bristol and Yorkshire.
The Small Ranunculus is strongly associated with brownfield sites as its main larval hostplant, Prickly Lettuce, is a ruderal species requiring disturbed ground and is often found at such sites.
Brownfield sites are important for the recovery of this species and very important habitats for many other moths and wildlife more generally. Threatened species such as the Bright Wave, Chalk Carpet, Wormwood and Four-spotted are all associated, to some extent, with brownfield sites.
In spite of this, brownfield habitats are very under-recorded and highly threatened by Government policies for redevelopment, or by landscaping schemes designed to turn ‘wasteland’ into parks.
Moth Night 2012, the national celebration of moths and moth recording, is encouraging moth recorders and the general public to find out more about the moths of brownfield sites. This will provide important info on biodiversity hotspots on brownfield sites and help map the return of the Small Ranunculus.
Small Ranunculus image by Les Hill/Butterfly Conservation