We know that some butterflies are more common that others. We usefully distinguish between the generalists – those insects that can be found pretty much anywhere, and the habitat specialists, whether that specialism is mountains, woodland, mangroves, rain forest or whatever. But what does it take for a butterfly to be accurately called “scarce”?
Let’s dispose of some of the silly ones first. What do we make of the Scarce Swallowtail? An absolute nonsense, of course – travel anywhere south of the Alps, and this striking but otherwise unremarkable butterfly is common as muck.
The problem here is the Anglo-centric tendency of common names. In the UK, Iphiclides podalirius is not just scarce, but entirely absent – the name seems to have come about as the result of two specimens being recorded from Shropshire, of all places, in the 1820’s. Even this record is almost certainly spurious and the result of, at best, either innocent or less-than-innocent releases of continental specimens. More recent twentieth records from Gloucestershire and Herefordshire would also seem to be untrustworthy, given that by now live pupa had become readily available by mail from dealers.
We then move to the Scarce Copper, Lycaena virgaureae – again not an unfamiliar butterfly to those who have spent time in Europe, but an insect not found in the UK. Once more the name appears to be a consequence of shady dealings in the eighteenth century, although there is a slightly stronger case for the insect to have once been resident in England – multiple records exist from Huntingdonshire, Lancashire and the West Country before the end of the nineteenth century, although the binomial L. virgaureae seems to have been erroneously ascribed to the much commoner L. phlaes by more than one early author.
We also have to deal with the tendency of lepidopterists to disguise the location of their catch to prevent other collectors hoovering up specimens, and unscrupulous dealers in Victorian times falsely according British status to specimens secured from overseas, in an attempt to increase the value of their insects for sale.
The Scarce Fritillary Euphydryas maturna is an attractive species, and one that is certainly hard to find. It occurs sporadically from Scandinavia to the Balkans in Europe, and as with its close relative, the Marsh Fritillary, populations fluctuate erratically from year to year, probably as a result of the prevalence of parasites. Here, for once, there is no attempt to claim this as a British species – it’s not just scarce, but entirely absent.
And then we have the Scarce Tortoiseshell, Nymphalis xanthomelas. Here we are on rather firmer ground. Modern records note an occurrence near Sevenoaks in Kent in 1953, and then the remarkable influx in 2014, with a number of reliable records from both south and eastern England. In the same year, The Aurelian photographed the insect himself in Bulgaria, apparently one of first records in the country for over fifty years, and has since encountered specimens at a location in eastern Turkey. But certainly within Europe, except perhaps for the eastern part of Ukraine and neighbouring Russia, “scarce” is a reasonable designation.
So, the moral of the story? English names for England, perhaps. Elsewhere – cave nomine – beware the name.