Fritillary butterflies belong to the family known as ‘Nymphalidae’. These butterflies have only two pairs of proper legs, the third pair are small, brush-like and useless for walking. Another distinctive feature of this family can be seen in the stage when the caterpillar pupates.
All butterflies in the Nymphalidae family suspend their pupa or chrysalis from a stem of vegetation using a silken pad created by the caterpillar and the pupae of many are angular in shape and decorated by golden metallic spots.
It was a pupa of a Nymphalidae butterfly which was first referred to as a 'chrysalis' since, in Greek, this means ‘golden’. Both the shape and decoration of this type of pupa is designed to give it better camouflage since it can look very much like a shrivelled leaf with dew drops on it.
Of the Nymphalidae family there are several sub-families, or groups, which occur in Britain and these include the red admiral, small tortoiseshell, painted lady and comma. The group presenting us with the greatest identification challenge are the fritillaries which have nine species in Britain and, during July, the largest of these takes to the wing.
All of the fritillaries are characterised by the striking orange colour of their wings marked with a dark chequered pattern. The silver-washed fritillary, Argynnis paphia, is the largest of its family in Britain and has a wing span of about 75mm.
Silver-washed fritillaries live in woodland glades and rides, so can be seen in gardens, they feed on nectar from a variety of flowers but those of brambles are very popular.
Courtship is often obvious since the female will fly along a ride with the male fluttering around her. When the female is looking for a place to lay her eggs she will fly low to the ground until she finds dog violets and then fly up to the nearest tree trunk to lay an egg about a metre above ground amongst the mosses for protection.
This fritillary was named because on the underside of its greenish-coloured hind wing are four bands of silvery-white washed-out stripes. This pattern is quite different to the silvery-white spots found on other large fritillaries.
It has suffered a serious decline in Britain during the 1970s and 80s but has since undergone something of a recovery, which may be weather related. It is one of the more common fritillaries in Britain and can be found roughly to the south west of a line between Kent and North Wales though there are also isolated pockets in other parts such as the Lancashire/Cumbria coastal area.