Yorkshire Status: Local resident.

The story of this species in Yorkshire is given below in the 2020 lockdown ramblings. Since then, Chocolate-tip has gone from strength to strength. In 2022 there was a big increase, with 89 records, and in 2023, there were 73 records of 78 moths from 44 sites, and although this was a slight reduction from 2022, the range has expanded dramatically with many records 20 to 30 kilometres further north. It has now reached VC65; two years faster than we had predicted from the previous rate of advance. It appeared at 24 new sites, most of these being in the southern half of VC62 and the east of VC64. It will be fascinating to see if this rate of advance continues. A large proportion of records came from the northern edge of the range and there were fewer from older sites in the south. This might be a case of it "outrunning" its parasitoids and making hay whilst the sun shines!

2020 (CHF): This species was known to occur in Yorkshire in the 19th century. In 1842 Robert Cook mentioned finding it "within five or six miles of the city of York" and in 1870 William Prest wrote - "towards evening we began our return to old Ebor, and on the way found a few larvae of C. curtula and retusa (Small Chocolate-tip) in spun together aspen leaves". As we already know that Prest found Small Chocolate-tip at Askham Bog, it is possible that this was the source of the Chocolate-tip. These two records were the only ones in Yorkshire for a long time as it retreated to the south east with its northern boundary on a rough line from Birmingham to north Norfolk, apart from a small population in Scotland. Since the turn of the century however, it has expanded its range and moved north. It appeared in the south of Yorkshire in 2009. Another was seen in 2013 and it has appeared every year since then in increasing numbers.

In 2020 there was a remarkable expansion of range and we now have a new frontier - Halifax and Keighley in the West, Brompton-by-Sawdon in VC62 in the north, Little Preston in VC64, and Wheldrake Ings to the south-east of York. A total of 17 sites in 2020 of which ten are new. Five records were of moths from a second brood. The big question is what will happen next. My guess is that the range will contract for the next two or three years, there will be a period of consolidation and "infilling", then it will be on the march again. It is probably enjoying being free of its usual parasitoids but I'm sure they will catch up with it. Of course, I might be totally wrong and it might carry on expanding. Speculating about this sort of thing is what makes recording so interesting. Perhaps it will reappear at Askham Bog and then will have come full circle. [it did this in 2022] My aspens are ready and waiting. There will be an MV trap underneath them this May.

Recorded in 59 (30%) of 200 10k Squares. First Recorded in 1842. Last Recorded in 2023. Additional Stats

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