Yorkshire Status: Local resident

The 2020 Lockdown ramblings below tell the rather interesting story of this moth and how it disappeared from the country and then reappeared. Colonisation of Yorkshire has continued in fits and starts since the first record in 2010. Some years there is no advance, and in other years it seems to jump big distances. It now seem to be established on both sides of the Tees, and in 2024 jumped about 30K to the Harrogate District. There are currently no VC65 records but it is only a matter of time. About 10% of our records are of the larvae on great lettuce or prickly lettuce; this being quite a high proportion in modern times when virtually all records are of moths in light traps.

2020 (CHF): Small Ranunculus has an interesting history in the UK. It was formerly resident in the south east of the country, along the south coast and into south Wales. In the 19th century larvae seemed to be a bit of a pest on cultivated lettuce. Towards the end of the century it went into decline and became much rarer. The last record was 1939. There was a gap of 58 years until two moths were found in Kent in 1997. Larvae were found the next year and colonisation of the London area was rapid over the next few years. The same situation happened in parts of Europe as it became common in some large cities in Denmark and Sweden such as Malmo and Copenhagen.

This species seems to have the ability to disperse long distances and rapidly form new colonies. In 2001 it appeared in Newport, Monmouthshire, and quickly became well established. In 2005 moths were found in the Merseyside area and again became established very quickly. Yorkshire was colonised in 2010 with single moths at Rotherham and Sprotbrough and although there were no records in 2011, it has occurred in varying numbers from 2012 onwards and this has been associated with a marked expansion of range. VC61 was colonised in 2014, VC64 in 2017 and VC62 in 2018. Range expansion is more impressive than the actual numbers of records which have not increased quite as much as I would have thought.

The situation altered in 2020 and numbers of records have shot up. This was again been associated with a marked range expansion. Western expansion has given us records at Bradford, Bramley and Otley, and one at Coniston Cold is a bigger jump north-west. Of even more interest is a record at Middlesbrough. This is suggestive of one of its long-distance dispersals and it will be interesting to see if this is another successful colonist. Something certainly has been happening to this moth in 2020; one of our own Yorkshire moth'ers even found the first two moths for Ireland!

The current wave of moths does not appear to be decimating the lettuces in our gardens as they have a taste for the wild ones. Larvae are frequently found in Yorkshire on both prickly lettuce and great lettuce, and have apparently also been found on wall lettuce in other parts of the country. The food plants have increased in range in recent years and are both now common on Teesside. I would not be surprised if we see a new colony in the Teesside area and perhaps further north, where spread is likely to be coastal. I suspect there will be less spread to the north-west unless other food plants such as wall lettuce are utilised.

Recorded in 50 (25%) of 200 10k Squares. First Recorded in 2010. Last Recorded in 2024. Additional Stats

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