The spot in question is Lempke’s Gold Spot, a rather lovely moth named after the Dutch lepidopterist, B.J. Lempke, who I believe was the first to discover this species in Europe (it had long been known in the USA). In Britain it’s mostly found in the northern half of the country, but there are a few records for the south.
Earlier today, Roy Leverton (author of the excellent Enjoying Moths) contacted me, in my capacity as Berkshire county moth recorder, regarding a potential Berkshire record of Lempke’s Gold Spot. This was published in a note by R.F. Bretherton, in the Entomologist’s Record for 1966 (available via the Biodiversity Heritage Library). In the note Bretherton refers to discovering that a specimen from his garden in Cumnor Hill, near Oxford, in 1940 had turned out to be Lempke’s Gold Spot, a species that had only recently been recognised as European at the time of the note.
I had no record for Lempke’s Gold Spot on the Berkshire database, and the species is not included in Brian Baker’s book on the county’s moths either, so this could have constituted a new species, the 638th, for the county list – always an enticing prospect! However, the question arises why Baker did not include the record in his book; many of Bretherton’s records were included, and Bretherton’s moth collection went to Reading Museum on his death, the museum for which Baker was natural history curator for many years, and retained an active interest in after his retirement.
So I am left wondering whether Baker saw the Lempke’s Gold Spot record or specimen and rejected it, or whether it didn’t get into his book because he was simply unaware of it. The ‘normal’ Gold Spot is very similar to Lempke’s Gold Spot (sometimes needing dissection to distinguish the two), and in Bretherton’s article he states that the specimen was of a worn individual, so there is an element of doubt.
What all this adds up to is that, unfortunately, the verdict has to be “not proven”, and the idea of Lempke’s Gold Spot being a Berkshire moth must remain an intriguing possibility. If only we could travel back to 1940 and have a look round at the habitats then available.