UK Butterflies
Building a Community of Responsible Butterfly Enthusiasts in Britain & Ireland
Building a Community of Responsible Butterfly Enthusiasts in Britain & Ireland
Wingspan
58 - 68 mm
Checklist Number
59.019
The Dark Green Fritillary is the most widespread fritillary found in the British Isles and is a pleasure to see as it flies powerfully over its grassland habitats, frequently stopping to nectar on Thistles and Knapweed. It gets its name from the green hue found on the underside of the hindwings, which are peppered with large silver spots. This butterfly can be found throughout the British Isles, although it is less common in central and eastern England. Outside of central Scotland and southern England, it is most frequently found in coastal areas and is the only fritillary found in Orkney and the Outer Hebrides. Despite its powerful flight, it is somewhat surprising that this species is not particularly mobile, staying within its breeding grounds.
| Family: | Nymphalidae | Rafinesque, 1815 |
| Subfamily: | Heliconiinae | Swainson, 1827 |
| Tribe: | Argynnini | Swainson, 1833 |
| Genus: | Speyeria | Scudder, 1872 |
| Subgenus: | ||
| Species: | aglaja | (Linnaeus, 1758) |
Description to be completed.
The distribution data (2000-2009) has been made available through the generosity of Butterfly Conservation and any subspecies distribution is taken from Riley (2007). Click here to see the distribution of this species together with site information overlaid.
The characteristic habitat of this butterfly is open, windswept calcareous grassland. However, in some areas it can also be found in woodland clearings and coastal dunes.
Although this species has declined considerably since the 1970s, especially in eastern England, the butterfly remains our most widespread fritillary and is not considered a priority species for conservation efforts.
The table below shows the occurrence (distribution) and abundance (population) trends, using information from The State of the UK's Butterflies 2015 (Fox, 2015). Any UK BAP status is taken from the UK Biodiversity Action Plan (UK BAP) (2007 review).
1976-2014 (%) | 1976-2014 (%) | 2005-2014 (%) | 2005-2014 (%) |  -33 |  +186 |  +44 | +18 |
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Adults generally emerge in the middle of June, reaching a peak in early July. In northern Scotland, adults emerge a little later at the end of June, reaching a peak at the end of July and early August. There is one generation each year.
Both sexes are avid nectar feeders and typically feed in early morning or late afternoon, when they will constantly fly from flower head to flower head staying at each flower for only a few seconds. This behaviour makes them very difficult to observe and it is sometimes easier to find a favourite flower and wait for a butterfly to come to you!
The males are the more conspicuous of the two sexes, and can be seen patrolling over large areas of habitat looking for a virgin female which often rest low down in vegetation. Once found, mating takes place almost immediately. A mating pair may be found resting on vegetation and will even continue to nectar while coupled.
Females are somewhat-easier to see when egg-laying, where they intersperse periods of nectaring with basking and bouts of egg-laying, when they will crawl deep in vegetation, searching out the lushest growths of larval foodplant before laying a single egg, although several eggs are often laid in the same area.
Adults feed primarily on knapweeds (Centaurea spp.) and thistles (Carduus spp. and Cirsium spp.). brambles (Rubus spp.), Buddleja (Buddleja spp.) and clovers (Trifolium spp.) are also used.
Eggs are laid either directly on the foodplant, or on a suitable platform nearby, such as a twig, grass stem or dead leaf. Eggs are yellow when first laid but turn a dark purple after a few days and, eventually, a dark grey just before the larva emerges. This stage lasts between 2 and 3 weeks.
"The eggs are laid singly on various parts of the plant, mostly on the under side of the leaves and stalks. The egg is 1mm. high, of a conical form; the extreme summit is sunken, the base rounded at the edge, otherwise flat. There are from nineteen to twenty-two longitudinal keels, greatly varying in length; some commence at the summit and run to the base, others at different intervals from the summit, but all run to the base and disappear just before reaching it. The keels are prominent and stand out in bold relief; the spaces between the keels are transversely ribbed (about twenty in number), which are most prominent near the summit. At first the colour is a pale primrose-yellow, which gradually deepens a little, and when five days old it is banded with lilac-purple and pale greenish-yellow, the lilac colouring occupying the greater part of the upper half, and a mottled zone near the base; it very gradually deepens in colour on approaching emergence, and when fifteen days old the summit is very dark purple and the central yellow zone is more ochreous; just before emergence the crown is dusky-brown and the remainder a light pearl-grey. The eggs commenced hatching August 12th, 1892, remaining seventeen days in the egg state. The last eggs hatched on August 18th, 1892." - Frohawk (1924)
The larva eats the eggshell on hatching and immediately enters hibernation in a curled up leaf or other piece of debris. The larva emerges in the spring and starts to feed on the tenderest new growth of the foodplant, either eating large chunks out of the leaf lobes, or eating the leaf entirely with the stem left standing. The larva is most active during sunny periods and can often be seen wandering across bare ground or short turf in search of the foodplant. The mature larva has a distinct colouring, being mostly black with a feint yellow band running down its back and a series of red spots running down each side. There are 5 moults in total.
The primary larval foodplants are Common Dog-violet (Viola riviniana), Hairy Violet (Viola hirta) and Marsh Violet (Viola palustris).
"The larva directly after emergence is 2.12 mm. long; it is rather stout in proportion, very sluggish in its movements and rolls into a ring when touched. The colour is pale ochreous, with a darker ochreous sub-dorsal area, and a similar coloured band on the ventral surface just above the claspers. There are eight longitudinal rows of shining black warts, each bearing a long hair; those on the dorsal surface are long, moderately thick, and terminate in a slight knob and are serrated throughout; each wart is situated on a brown disc. All the dorsal hairs curve forward and are of a deep amber colour. The two central dorsal rows of warts are united at their base, the anterior one is the smallest, and the hair only half the length of the posterior one. The warts forming the sub-spiracular series are four in number on each segment, three are united and the fourth nearly so; these each bear a straight, finely pointed, serrated hair directed downwards, excepting the one immediately below the spiracle, which is slightly upturned; a few other smaller hairs occur on the ventral surface. The head is black and covered with a number of paler warts and hairs, similar to those on the body. The legs are black and ochreous and the claspers pale ochreous. On the first segment is a dark brown, coronet-shaped dorsal blotch. The larvae enter into hibernation immediately after leaving the egg, therefore they feed on nothing (except the portion of the egg-shell which they eat out to emerge) until after hibernation. Towards the end of March, 1893, the larva awoke from hibernation, and commenced feeding on the younger leaves of dog violet on the 28th, thus living without food for 228 days." - Frohawk (1924)
"The first moult took place on April 9th, 1893. Soon after it measures 3.2 mm. in length. The ground colour is an ashy-grey with a slight ochreous tinge. There are six longitudinal rows of shining black spines, each furnished with a number of black spinelets; the greyish ground colour between the rows gives the larva a striped appearance; the spines are sub-dorsal, super-spiracular and sub-spiracular; the latter are situated on an ochreous stripe; the medio-dorsal grey stripe is conspicuous and is finely divided by a darker line. The head is black and shining, beset with warts and black hairs. Just before second moult it is 4.8 mm. long." - Frohawk (1924)
"The second moult occurred on April 21st, 1893, remaining twelve days in second stage. After the second moult the colours are more clearly defined, the grey ground colour being replaced by white, forming longitudinal white stripes; the sub-spiracular band is composed of a large circular blotch of pale amber in colour on each segment, in the centre of each is a spine; in other respects it is similar to previous stage. When fixed for third moult it measures 7.6 mm. in length. For moulting the larva spins a thin web of silk upon the under surface of the leaf and thereon fixes itself for the process (at each moult)." - Frohawk (1924)
"The third moult was on April 28th, 1893, the third stage lasting seven days. After the third moult it measures 12.7 mm. long. The ground colour is deep lilac-grey. The sub-dorsal and super-spiracular spines are situated on black longitudinal bands. Below the lateral series of spines, which have orange-tawny bulbous bases, there is a dilated lateral stripe of a cream colour; this is sharply defined against the deep olive colour of the under surface; the segmental divisions are clearly defined by fine white bands; the sides are also checkered with white markings; in other respects it is the same as the previous stage. The larva are active in the sunshine, when they feed and bask in its warmth; in the shade they remain quiet. If disturbed they run with great activity. Frequently after feeding they crawl from the plant into the open and there bask in the sun, or else lie at full length on the upper surface of the leaves fully exposed to the sunshine." - Frohawk (1924)
"The fourth moult took place on May 5th, 1893, the fourth stage also occupying seven days. Four days after the fourth moult it measures 16 mm. long while at rest. Excepting the general colouring, which is deeper, and the lateral series of orange spots are now deep orange, the whole of the larva appearing much darker, it is similar to the former stage." - Frohawk (1924)
"The fifth and last moult occurred on May 15th, 1893, remaining ten days in the fifth stage. After fifth moult, fully grown, it measures 38 mm. in length. The head is narrower than the first segment; the body tapers at each end, especially the anterior. There are six longitudinal rows of spines, which are placed sub-dorsally, super-spiracular and sub-spiracular, from the fourth to eleventh segments inclusive. On the third segment in place of the sub-spiracular spines are warts only; the first two super-spiracular spines are situated between the segments and lower down than the rest. The anal segment has only four spines, and it terminates in a blunt conical point. All the spines and warts are shining black, and covered with sharply pointed, stiff spinelets. The ground colour of the dorsal surface is velvety-black, shading into purple-brown on the sides and ventral surface. It is slightly speckled with ashy-white; the segmental divisions are plainly defined by a series of transverse ashy-white marks; on each segment from the fourth to eleventh inclusive is a fairly large deep orange blotch adjoining the sub-spiracular spine. The head is dull olive-black, rather thickly covered with short and long hairs; the legs are black and finely haired, the claspers black and ochreous. The larvae feed by day, especially during sunshine, and are very active, and when disturbed run very rapidly. The larva above described (the same individual all through) spun up for pupation on May 29th, 1893, and pupated on June 1st, remaining fourteen days in the last stage." - Frohawk (1924)
The larva creates a loose tent by drawing together several leaves and other pieces of vegetation together. The pupa is formed upside down, secured to the top of the tent by the cremaster. This stages lasts between 3 and 4 weeks, depending on the weather.
"The pupa is 19 mm. long, exclusive of the terminal segments, which are abruptly curved under, and 8.5 mm. wide across the middle (lateral view), its greatest diameter. Lateral view: The head is rounded; the thorax is lobed and keeled dorsally, and strongly concave between the thorax and abdomen; the second abdominal segment rises abruptly; the abdomen is acutely curved, so much so that the anal segment almost touches the apex of the wings; the latter are rather bulging along the costal margin, and keeled along the inner margin. Dorsal view: The head is tri-lobed in front, the base of the wings angular and projecting, and the basal half of the inner margin is convex, then sunken, and the abdomen is swollen at the fourth segment and then tapering. There are two sub-dorsal rows of small conical points running the entire length of the pupa: the first pair on the head, the second on the thorax, and a pair on each abdominal segment, and on the third, fourth and fifth segments are very much smaller super-spiracular points. The ground colour is ochreous on the head, thorax and wings; the abdomen is tawny or orange-ochreous. The head and thorax are heavily blotched with brown-black, and a large triangular patch of the same colour spreads over the greater area of the apical half of the wings; the anal segment is black and the next is almost so; the spiracles are surrounded by black, and deep purplish-brown blotches encircle the body at each segmental division, and the ochreous colouring of the wing is reticulated with the same dark colour; the legs are mottled and very finely reticulated with black and ochreous. The anal segment is shining, but the rest of the pupa is less so. The general colouring of the pupa has exactly the appearance of being scorched or burnt. It is attached by the cremastral hooks to a pad of silk spun on the stem of a plant or leaf stalk, with the surrounding leaves or stems drawn together, forming a tent-like shelter. The above is a description of the pupa, when six days old. The imagines emerged at the end of June and beginning of July, 1893." - Frohawk (1924)
The following links provide additional information on this butterfly.
