The white ‘c’ – visible in mirror image on the underside of the wings – is clearly visible, and the comma was also known in older Dutch as the c-vlinder (c-butterfly). Photo: Kars Veling, De Vlinderstichting.
The comma is turning up in towns and cities ever more frequently, and one individual is currently in the process of pupating in the NIBI’s back garden.
On 15 May, a caterpillar of the comma (Polygonia c-album) appeared in the back garden of the NIBI in Bilthoven, busily munching away on a redcurrant bush. When the Dutch Butterfly Conservation announced on Biodiversity Day that the comma is indeed thriving in urban environments (Nature Today, 22 May), our butterfly was quietly getting on with pupating. The winter form – which is less conspicuous thanks to darker colouring on the underside – has ‘more or less disappeared by now, but the new generation is already making itself known’, the Dutch Butterfly Conservation accurately reports.
This refers to the summer form, with brighter colours and less deeply incised wing margins, also known as forma hutchinsoni. A tribute to the British butterfly expert Emma Sarah Hutchinson (1820–1905), who encouraged Victorian ladies to study butterflies and plants (Entomology and Botany as Pursuits for Ladies, 1879) and contributed greatly to knowledge of the life cycle of butterflies. A classic is her publication on the comma and possible measures to halt the decline of this butterfly (The Entomologist, 1881). In the Netherlands, too, the comma long suffered a decline, but since the 1970s it has been one of the few butterflies that appears to benefit from warming temperatures and urbanisation.
The Dutch name is of course owed to the deep incisions in the wings and the orange to brown colouring (aureus is ‘gold’ in Latin). The ‘gehakkelde’ (jagged) element also features in the genus name Polygonia: many-angled, from polus and gonia. The species epithet c-album refers, amusingly enough, to the small white ‘c’ on the underside of the wing. An older Dutch name was therefore the witte-c vlinder (white-c butterfly), and the Germans (C-Falter) and French (Papillon-c) have likewise noticed the little letter. The British, naturally, see things differently and make out a white comma – hence the name comma. The NIBI is eagerly awaiting a comma forma hutchinsoni.
Update:
Pupated
On Wednesday 11 June, the comma – complete with its white ‘c’ – emerged from its chrysalis in the NIBI garden. Photo: Tycho Malmberg, NIBI.
See also:
–Comma – Polygonia c-album – Website De Vlinderstichting
–Emma Hutchinson – Wikipedia