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Speckled Wood

Pararge aegeria

pa-RAH-jee ee-JEER-ee-uh

Wingspan
♂ 46 - 52 mm, ♀ 48 - 56 mm

Checklist Number
59.003

Speckled Wood

Pararge aegeria

pa-RAH-jee ee-JEER-ee-uh

Wingspan
♂ 46 - 52 mm, ♀ 48 - 56 mm

Checklist Number
59.003


The Speckled Wood is a common butterfly and familiar to many observers, especially in woodland where, as its name suggests, it is most often found. The appearance of this butterfly changes from north to south, forming a "cline", where individuals in the north are dark brown with white spots, with those in more southerly locations being dark brown with orange spots. This has given rise to a number of subspecies.

In England this butterfly is found south of a line between Westmorland in the west and South-east Yorkshire in the east, with a few scattered colonies further north. It is also found in the west and north of Scotland, but is absent from the south, the Outer Hebrides, Orkney and Shetland. It is widespread in both Wales and Ireland, but is absent from exposed high ground. This species is expanding its range and it is anticipated that it will eventually fill the gaps in its distribution.

The species was first defined in Linnaeus (1758) as shown here (type locality: Southern Europe and Mauritania). The nominate subspecies has not been recorded in Britain or Ireland.

This subspecies was first defined in Godart (1821) as shown here and as shown in this plate (type locality: Germany).

This subspecies occurs through the range of this species, with the exception of Scotland and the Isles of Scilly. The spring brood has larger cream spots than those of the summer brood.

Pararge aegeria ssp. tircis (Godart, 1821)

Original (French)

Le dessus des ailes est d'un brun-obscur, avec des taches d'un jaune-d'ocre. Les ailes supérieures en ont une douzaine, sans compter un oeil noir à prunelle blanche, placé vis-à-vis du sommet. Les ailes inférieures en ont deux, derrière lesquelles il y a une bande pareillement jaune, offrant quatre yeux noirs, dont l'antérieur plus petit et sans prunelle, les autres avec une prunelle blanche.

Le dessous des premières ailes ressemble au dessus; seulement le fond et les taches en sont un peu plus pâles. Le dessous des secondes ailes est d'un gris-verdâtre légèrement chatoyant, avec deux lignes brunes, transverses, ondulées, à la suite desquelles il y a deux taches jaunâtres, puis une rangée courbe de cinq à six points blanchâtres entourés de brun, enfin une teinte violâtre qui couvre presque tout le bord postérieur.

Les antennes sont colorées comme dans les deux espèces précédentes; mais leur massue est en fuseau.

Translation

The upperside of the wings is dark brown, with spots of yellow-ochre. The forewings have a dozen of these, as well as a black eyespot with a white pupil positioned towards the apex. The hindwings have two (yellow ochre spots), behind which there is a band of a similar yellow colour, showing four black eyespots, of which the foremost is smaller and lacks a pupil, the others having a white pupil.

The underside of the forewings resembles the upperside; only the ground colour and the spots are a little paler. The underside of the hindwings is green-grey, slightly lustrous, with two brown, wavy, transverse lines, outside which there are two yellowish spots, then a curved array of five to six whitish points surrounded by brown, finally a violet tint which covers almost all the outer margin.

The antennae are coloured as in the two preceding species [Wall, Large Wall]; but their club is tapered.

Spring Brood

Summer Brood

This subspecies was first defined in Harrison (1949) (type locality: Loch Scresort, Isle of Rhum, Scotland).

The initial distribution of this subspecies of Loch Scresort, Rhum, was extended by Howarth (1973) to include Canna and by Dennis (1977) to include Oban and northern Argyll. Thomson (1980) extends the distribution to include western and north-western Scotland and its neighbouring islands: "The subspecies oblita inhabits the western part of Argyllshire, western Inverness-shire and as far north as Inverewe, Ross-shire, including Mull, Ulva, Canna, Rhum, Skye, Jura and possibly other islands of the Inner Hebrides. The newly discovered populations of eastern Ross-shire, eastern Inverness-shire, Nairnshire and Morayshire, and the extinct colonies in Wigtownshire, Ayrshire and Lanarkshire, probably also belong to this race". Aldwell & Smyth (2015) extend the distribution of this subspecies further: "Some of the Donegal photographs revealed the presence of another subspecies there P. aegeria oblita".

Like the subspecies tircis, the spring brood has larger cream spots than those of the summer brood. It differs from the subspecies tircis as follows:

  • 1. The overall appearance is much whiter.
  • 2. There is a much great contrast overall, with the dark markings appearing blacker and the pale spots appearing whiter.

According to Howarth (1973) this subspecies has "larger ocelli on the upper side of the hind wings than tircis Butler". Dennis (1977) also says that "the lilac marginal band on the hindwing underside is more purple and more extensive".

Pararge aegeria ssp. oblita (Harrison, 1949)

♂ ♀. Ground colour above and below much whiter than in the form aegerides Stgr., and the blackish markings above and below definitely blacker in the more intensively marked areas and greyer elsewhere.

♂ Holotype - Loch Scresort., Isle of Rhum, August 8th, 1948.

♀ Allotype - same data.

Spring Brood

Summer Brood

This subspecies was first defined in Howarth (1971a) (type locality: Isles of Scilly, England).

This subspecies represents the population found on the Isles of Scilly. Like the subspecies tircis, the spring brood has larger spots than those of the summer brood. It differs from the subspecies tircis as follows:

  • 1. The upperside has better-developed orange markings, especially those surrounding the spots on the hindwing.
  • 2. The underside of the forewing has orange, rather than cream, markings toward the centre.
  • 3. The underside of the hindwing has a darker purplish-grey area at the margin, providing more contrast.

Pararge aegeria ssp. insula (Howarth, 1971)

While on a visit to the Scilly Isles during September, 1970, Mr. Austin Richardson discovered a small and isolated colony of Pararge aegeria (L.) on the isle of St. Mary's; specimens from this colony are here described as a new subspecies.

Compared with ssp. tircis Butler from southern England the ground colour of ssp. insula is a deeper yellowish orange and more nearly resembles that of the nominate subspecies aegeria from southern Europe. The specimens in the type series were all taken in September and therefore are representatives of a late second or possible third brood. However, in general appearance and size of markings, they resemble the first rather than the second generation, form aestivalis Fruhstorfer [Fruhstorfer (1909)] of ssp. tircis.

The following description is a comparison with the latter:

Male. Upperside. The orange markings are better developed, particularly those surrounding the post-discal series of ocelli on the hindwing and the spot is space 5. Underside. The forewing has the base of space 2 filled with a broad, almost clear orange marking which is immediately above and adjacent to a similar marking in space 1. In aestivalis the latter is broadly darkened basad and the marking above suffused. The hindwing has the purplish grey marginal area slightly darker and in more contrast to the discal markings so that the wing appears slightly more variegated in coloration.

Female. Upperside. Similar to the male but the tawny markings are better developed, particularly the marking at the base of space 2 and that immediately below it, which, in this area of the male is partially obscured by the androconial brand. Underside. Similar to that of the male.

Holotype. ♂, Scilly Isles, St.Mary's, ix.1970, Austin Richardson, B.M. 1970-712.

Allotype ♀, same data as holotype.

Paratypes: 11 ♂, 1 ♀, same data as holotype.

Spring Brood

Summer Brood

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.

As its names suggests, this butterfly is primarily found in woodland, but can be found anywhere there is sufficient scrub to provide the shaded conditions that this butterfly favours which includes gardens and hedgerows.

This is one of our few species that is doing well, with a sustained expansion to its range. It is believed that this butterfly has benefited from a reduction in coppicing, resulting in shadier woodland that this butterfly favours. As such, it is not a species of conservation concern.

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).

UK BAP Status
Occurrence Change
1976-2014 (%)
Abundance Change
1976-2014 (%)
Occurrence Change
2005-2014 (%)
Abundance Change
2005-2014 (%)
Not Listed
Large Increase +71Large Increase +84Stable +3Stable +4

This species is unique among the butterflies of the British Isles in that it can overwinter in 2 stages, as both a larva and pupa. As a result, there is a mixed emergence with adult butterflies on the wing from April through to September, with a few adults being seen as early as March or as late as October, especially at southern sites. There are 2 or 3 generations, depending on location and weather conditions and adults of later generations are generally darker than those emerging earlier in the year.

"Ova laid May 18th, 1890. Hatched May 28th, remaining nine days in the egg state. First moult 6 a.m., June 6th. Second moult evening, June 11th. Third moult 2 p.m., June 18th. Fully grown June 24th. Pupated June 25th, evening. Butterflies emerged during the second week of July, 1890. First brood. Ova laid July 7th, 1890. Hatched July 17th, remaining ten days in the egg state. Spun up August 8th. Pupated morning, August 10th. First imago emerged August 24th, being fourteen days in the pupal state. Second brood. Ova laid September 17th, 1902, which produced butterflies in March (first emerged on 15th), 1903. Ova laid during the second week of September, 1909; by October 12th all the larvae except three out of about fifty had moulted first time, and some almost ready for second moult. Second moult, end of October. Third moult, end of March, 1910. Pupated (first one April 23rd, 1910. Imago emerged May 20th, 1910." - Frohawk (1924)

Pararge aegeria ssp. tircis

Pararge aegeria ssp. oblita

Pararge aegeria ssp. insula

This butterfly is often seen in more-sheltered conditions than other species and is often the only species seen in dappled shade, or in overcast conditions.

The male is territorial and will inhabit a particular clearing or hedgerow, where he will rest on a prominent sunlit perch waiting for a passing female. Other males are soon seen off before the defending male returns to a favourite perch. If no suitable territory can be found, or when there is a large number of males, the male will patrol in search of a mate instead. When a male encounters a receptive female, which has a more laboured flight than the male, she will fall to the ground or a nearby leaf where, after a brief courtship, the pair mate.

Both sexes feed from honeydew, but also take nectar from a variety of plants when honeydew is scarce, such as Ragwort.

Adults feed primarily on Honeydew (N/A). brambles (Rubus spp.), Common Fleabane (Pulicaria dysenterica), Cuckooflower (Cardamine pratensis), dandelions (Taraxacum spp.), ragworts (Jacobaea spp.), Sap (N/A) and Wild Privet (Ligustrum vulgare) are also used.

Spring Brood

Summer Brood

Spring Brood

Summer Brood

Spring Brood

Summer Brood

The spherical eggs are very light green in colour are laid singly, sometimes in pairs, on the underside of a leaf of the foodplant. It is believed that temperature is a major factor when a female chooses a plant on which to lay. In spring and autumn eggs are laid on plants in more-open positions than those laid in the summer, when more-shaded plants are used. Eggs hatch after 1 to 3 weeks, depending on temperature.

"The egg is 0.80 mm. high, of a spheroid form, widest near the base. The colour is of a translucent greenish-yellow. The whole surface is finely reticulated, forming a fine honeycomb pattern over the crown and base, and delicately keeled down the middle. The keels are very irregular and connected by fine transverse ribs, which gradually form into shallow hexagonal cells on nearing the summit and base. The egg does not alter in colour owing to the larva being of similar colouring to the egg, excepting that shortly before the emergence of the larva its dark head shows clearly through the delicate shell, making the crown of the egg very dark. The eggs are laid singly on blades of grasses." - Frohawk (1924)

The young larva sits on the underside of the leaf feeding, both day and night, from the leaf edge toward the midrib. Larger larvae will move from plant to plant to feed and, as winter approaches, will rest at the base of the plant. Depending on the temperature and amount of daylight, some larvae will reach pupation, this species being the only butterfly in the British Isles that passes the winter in 2 different stages - as larva and pupa, although it is believed that only 3rd instar larvae are able to successfully overwinter. This stage can be passed in as little as 25 days when the temperature is high. There are 3 or 4 moults in total.

The primary larval foodplants are Cock's-foot (Dactylis glomerata), Common Couch (Elytrigia repens), False Brome (Brachypodium sylvaticum) and Yorkshire-fog (Holcus lanatus).

1st Instar

"The larva, directly after it emerges, eats the empty egg-shell, leaving only the base, which is attached to the grass. Directly after emergence the larva measures 2.5 mm. long; it is cylindrical, of a pale primrose-yellow; the head is large and globular, intensely black and shining. On each segment are ten olive-coloured tubercles forming longitudinal series, each bearing a white serrated hair; those along the dorsal surface are the longest and curve backwards, the super-spiracular hair curves forwards and the two sub-spiracular hairs project laterally, these form a straight lateral series; on the base of each clasper is a similar but smaller pair. The spiracles are also of an olive colour. The hairs on the first segment are all directed forwards and those on the last segment project backwards; the head bears a number of similar hairs of different length, all curving forwards; the claspers and legs are the same colour as the body. Before the first moult it measures 4.20 mm. long. The colour is a clear yellowish-green, with a darker green medio-dorsal line, bordered on each side by a fine whitish line, a sub-dorsal white line, broadest on the anterior segments, and a fine lateral whitish line." - Frohawk (1924)

2nd Instar

"Before the second moult it is 8.5 mm. in length. The ground colour is a clear light green, with a rather darker pure green medio-dorsal longitudinal stripe, bordered by a yellowish-white line; then a band of mottled whitish-green, followed by a sub-dorsal white line, and two other less distinct white lines below, one above and one below the spiracles, which terminate in the white anal points. The whole ventral surface, including the claspers, is light green. The head is pale opaque green, and covered with rather long hairs, and the eye spots are black. The body is thickly sprinkled with fine, slightly curved hairs, varying in length; some are white and others black." - Frohawk (1924)

3rd Instar

"The second moult occurred at the end of October, 1909, and shortly after they entered into partial hibernation and rested upon a little layer of silk spun on the grass stem. By the beginning of February, 1910 (after the second moult), when 126 days old, the larva measures 10.5 mm. long; excepting being rather darker green it is similar in all respects to the previous stage. Just before the third moult it measures 12.7 mm. long. One fixed for moulting March 20th and moulted the third time on the 27th, being seven days undergoing the change." - Frohawk (1924)

4th Instar

"After third moult, fully grown, 200 days old, it varies in length from 25 mm. to 28.6 mm. It is slender and tapers at each end; the head is prominent and slightly notched on the crown, each lobe being very slightly pointed on the top, and sprinkled with green warts of various sizes, each bearing a proportionate greyish hair; the eye spots are brown and placed on a cream-coloured band; the thoracic (first three) segments are divided into four sub-divisions, the remaining segments into six, the first sub-division being the widest. The ground colour is a clear grass-green, with a darker dull green medio-dorsal longitudinal stripe, faint on the first two segments and attenuated at the ends, and bordered by a light greenish-yellow line and a fainter and narrower sub-dorsal line, followed by three more still fainter and rather wavy lines, one super-spiracular, one spiracular and one sub-spiracular; the spiracles are small and yellow. The whole of the ventral surface, including the claspers, is a clear translucent green; the legs are paler; the whole surface is sparsely sprinkled with minute whitish warts, each bearing a greyish, slightly serrated hair similar to the head; those on the dorsal surface are most clearly pronounced, and the warts, or rather bases, of the hairs form short tubercles; the surface of the body is very finely granular; the anal segment projects and terminates in two diverging whitish points covered with grey hairs. Before pupation the stripes and lines gradually become fainter, the entire colouring being a clear green, the medio-dorsal stripe being only just visible. During the last few days they feed almost unceasingly. When suspended for pupation it hangs in a distinct loop, with its head brought up to the ninth segment, almost touching the claspers. One suspended itself on April 20th and pupated April 23rd, another hung up April 24th and pupated April 27th." - Frohawk (1924)


The pupa is formed head down from a grass stem or nearby leaf litter, attached by the cremaster. This stage can be as short as 10 days for those pupae that go on to produce adults in the same year.

"The pupa measures 12.7 mm. long and 6.35 mm. wide across the middle of the abdomen; although stout in proportion it is of beautiful formation. Side view: Head beaked in front, the crown gradually rises to the swollen meso-thorax, which has a slight medio-dorsal keel; it is sunken at the meta-thorax; the abdomen is swollen and rounded at the middle and abruptly attenuated, and ending in a well developed cremaster; the ventral surface forms an undulating outline, the apical half of the wings ample and rounded. Dorsal view: Head bi-angulated, having two conical lateral points; base of wings with angular projections, the inner margin with a ridge; abdomen ample and rounded, abruptly tapered and terminating in a well developed, slightly cleft, dorsally grooved cremaster, amply provided with long-stalked, amber-brown hooks, exactly like those of Coenonympha pamphilus. At first the colouring is a brilliant translucent green, which gradually becomes opaque, and the normal colour is attained when twenty-four hours old. It varies in colour from dull greenish-olive-buff to brilliant green. The dark variety has the ground colour pale, dull olive-green over the head, thorax and wings, and the abdomen bullish; it is finely streaked and speckled with brown; the neuration and outer edge of inner margin of wing black; also three dark blotches along the costal margin and other dark blotches on the legs; there are four longitudinal dull olive-brown stripes on each side of the abdomen and a medio-dorsal band more or less green; a white stripe runs along the inner margin of the wing bordering the black outer streak; the ventral frontal edge of the head is outlined with white. There are two sub-dorsal rows of white tubercles on the abdomen, commencing on the second and ending on the sixth segment; the spiracles are pinkish. The green variety varies in intensity, some are grass-green and others of a beautiful brilliant pure green. In both forms the markings are of different shades of green; the entire surface is beautifully reticulated and checkered with pure green on a greenish-white ground. The white tubercles and markings are similar to those of the dark form. The whole surface is quite smooth. The pupa is firmly attached by the cremastral hooks to a pad of silk spun on a grass stem; usually the cast larval skin adheres to the silken pad. The larva feed upon various grasses. The common annual meadow-grass (Poa annua) is as suitable as any as a food plant for P. egeria. One imago emerged May 20th and another emerged May 24th, remaining twenty-seven days in the pupal state." - Frohawk (1924)