Silver-washed Fritillary Argynnis paphia (Linnaeus 1778)
Family: Nymphalidae, subgroup Argynninae (the Fritillaries)
Header photo by P Simmons
Photo above right by Chris Abbott
Other 2 photos above by Iain H Leach
The Silver-washed Fritillary is a very large butterfly, as large as a Red Admiral or even larger. It is a rich orange-brown dotted and blotched with black.
Males have four prominent sex brands on each of the upper forewings which appear as parallel black bars along four of the wing veins on each forewing. In closed-wing view both sexes are greenish, stippled with silvery bars, giving a 'silver wash' effect. In some populations up to 15% of females have a dusky grey-green background colour replacing the orange-brown on the upperwings, and a delicate pink wash on the lighter parts of the lower underwings. This variation, known as valesina appears to be more common in some years than others. Males don't seem very keen on these dark females, but they are better able to absorb heat and fly in dull conditions. Many other varieties occur with some 50 aberrations described.
The species is a butterfly of open, broad-leaved woodland, and sheltered wooded lanes. lt particularly favours oak woodlands though where the species is fairly common, it will sometimes visit gardens and nectar on buddleia. It also requires violets of any species to be available as its larval foodplant.
Adults are strong fliers, feeding high up on honeydew, and at ground level on various plants such as brambles and thistles.
The range of this species covers from the north of Spain to Ireland and south west England, some of Scandinavia and east across Europe and Asia to China and Japan.
In Britain it is locally common in the south west, bounded by a line from the Mersey to the Thames and has shown recent signs of range expansion (hence BC's Low priority). The natural spread of the species has been clouded by recent unofficial releases, which may have affected some Midlands counties and Cumbria.
The Silver-washed Fritillary became extinct from Yorkshire for a long time, except for occasional wanderers. It may have been more common a hundred years ago in east Yorkshire but had more or less disappeared before 1950. This may have been due to the national range reducing because of changes in woodland management, which abandoned coppicing and allowed close growing conifers to shade out the growth of violets. The species is extremely hardy and able to survive the coldest winters, even in Siberia, so theoretically, weather conditions should not be a problem.
However between 1976 and 2014 the species increased nationally by nearly 60% and has reappeared in Yorkshire. It can be seen occasionally on sites such as Bishop Wood near Selby and Thorpe Perrow near Bedale.
The eggs are laid on tree trunks up to two metres off the ground and occasionally up to six metres. The larvae hatch after two to three weeks and go into hibernation almost immediately, hiding away in the bark. They become active again in March to April, descending to the ground in search of violets, and developing through five instars. Pupation takes place in late May, lasting two to three weeks according to the weather.
The adults are on the wing from mid June to late August in Britain.
UK BAP Status: Not on threatened list
Butterfly Conservation priority: Low (but a regional priority in several regions)
There are around 50 aberrations that have been described. However very few specimens are seen in Britain for comparison purposes.
With thanks to the Butterflies of Yorkshire edited by Howard M Frost
Catherine Jones 10/11/20