Yorkshire Status: Very rare and very local migrant/wanderer.
Argus 52, 2006: This moth is currently going a major range expansion from its stronghold in the Thames Valley. In the recent Rothamsted report Least Carpet was top of the table of moths increasing in number. It will be interesting to see whether it continues to spread throughout Yorkshire. VC61. Kilnsea, 5.7.2006 (BRS). NEW COUNTY RECORD.
Current status (CHF, 2011): NEW COUNTY RECORD - Spurn 2006 and 2008. This species was first recorded in London in 1831. A major range expansion to the north and west took place from the 1950s and in the Rothamsted data, the population increased by 41,000% between 1968 and 2002 making it the moth with the greatest population expansion. It was only a matter of time before one reached Yorkshire, and we are likely to see more in years to come.
Argus 81, 2017: The north-westerly spread across the country is progressing in fits and starts. In addition to the new record for VC63, the first arrived for Nottinghamshire at about the same time.
VC63. Potteric Carr NR, 9.7.2017 (RI&JCH, HEB). NEW VICE-COUNTY RECORD.
Argus 87, 2019: A large increase in numbers accompanied by considerable spread in its range to northern VC62, the west of VC63 and into VC64. Other species which have undergone rapid spread sometimes contract back for a period of consolidation before further expansion and it will be interesting to see whether this happens with Least Carpet.
VC62. Skelton, 31.7.2019 (DM). NEW VICE-COUNTY RECORD. VC64. Burley-in-Wharfedale, 1.8.2019 (P&AR). NEW VICE-COUNTY RECORD.
2020 (CHF): Least Carpet has had another good year. This illustrated a typical way that moths colonise the county. Many species have invaded us from the south east with very similar patterns to this. The typical scenario is illustrated well here:
1. First arrives in the county at Spurn (2006). 2. A gap of a few years then more records from Spurn and the occasional record further up the coast (2013). 3. Starts to appear every year at Spurn. 4. The first appearance in the south-east of VC63 (2017). 5. A period of major expansion, in this case with records up to the north of VC62, into the west of VC63 in Calderdale and into VC64 in Wharfedale (2019). 6. A period of contraction and consolidation, with filling in in VC61 (2020). This year it involved six different sites and four different 10K squares.
I would expect the next couple of years to show more consolidation in VC61 followed by a slower and steadier spread north and west. The only probable second brood example we have had was the Calderdale moth on 27.9.2019, but second broods are likely to become more common. This is of course all dependent upon weather patterns and may well be influenced by the presence or absence of its parasitoids which may well check the spread. Many other species have shown variations of this pattern including Vine's Rustic, Scarce Footman, Pine Hawk-moth, Dingy Footman and the recent wave of Coronet. There are one or two species which look as if they are going to do the same in years to come for example Tree-lichen Beauty and Toadflax Brocade.
Recorded in 26 (13%) of 200 10k Squares. First Recorded in 2006. Last Recorded in 2022. Additional Stats