Hairstreaks, Coppers & Blues: Family Lycaenidae

Members of this family are small and most are brightly coloured with a metallic sheen to the upperside of their wings. The Hairstreaks, named for the fine streaks on the undersides of their wings, have short ‘tails’ on their hind wings, which are frequently missing in individuals I’ve seen, probably lost to a bird attempting to grab it in its beak. The sexes are often very different; female blues are usually brown and nothing like the males. Hairstreaks usually frequent trees and shrubs and are notoriously difficult to spot, but most coppers and blues fly close to the ground.

GREEN HAIRSTREAK – Callophrys rubi

Wingspan: 27-34mm  Flight period: April to July

I have to confess that I am yet to see this butterfly here in North Wales, but I know they are present in my area as other people have seen and recorded them. I’m sure I’ll get lucky one day, but meanwhile I feel I can include it in my collection on the basis that I did used to see them occasionally in my garden when I lived in South Wales. The photographs are mine, but taken in Spain where I saw them more frequently.

Green Hairstreak on Gorse - Southern Spain

Green Hairstreak on Gorse

Habitat: This is the most widespread of our UK hairstreaks and unlike most of the others, is not tied to a particular habitat and can be found on moorland and roadsides as well as in woodland clearings.

Caterpillar: 15mm: May to July

Ground colour green, with yellow and darker green triangles along the side of the body and a cream/yellow line running through the spiracles. Their foodplants include gorse, broom and other low-growing shrubs, including rockroses.

Behaviour: Although widespread, the Green Hairstreak is also a local species and forms distinct colonies which can vary greatly in size. Both sexes always settle with their wings closed, the brown uppersides only ever being seen in flight. The undersides, by contrast, give the illusion of being green, (an effect produced by the light on the wing scales), which provides excellent camouflage as the butterfly rests on a favourite perch, such as a Hawthorn branch. This butterfly will also regulate its body temperature by tilting its wings appropriately to catch the sun’s rays.

Distribution: Widespread throughout most of the British Isles, but absent from the Isle of Man, Outer Hebrides, Orkney and Shetland.

UK Butterflies Status: Both distribution and population trends show a decline and the conservation status of this butterfly is kept under review as a result.

PURPLE HAIRSTREAK – Favonius querqus

Wingspan: 31-40mm males slightly larger than females  Flight period: July to September

My first, and to date only encounter with this lovely little butterfly was completely unexpected and all too brief. It caught my eye as I was attempting to photograph a Speckled Wood basking on another leaf of the same Oak tree and I managed to get just one clear shot. It moved slightly to reveal two small orange eyespots on the hind wing, but while focussing to get a further shot the Speckled Wood flew up and chased the Hairstreak away.

Habitat: This butterfly is primarily found in woodland containing oak trees, the leaves being the foodplant of the larva. However, the species can be found in any location where oaks occur, including lanes, parks, and other urban areas.

Behaviour: The adult butterflies spend most of their time around the tops of tall oak trees, where they fly and feed primarily on honeydew & sap, but they may also takes nectar from bramble, hogweed and hemp agrimony. The best chance of seeing one is when they are freshly emerged, when they can sometimes be spotted lower down in a tree. Most likely they will be resting with only their silver-grey underside visible, as the one in my photograph, but sometimes they will open their wings momentarily to reveal a flash of  the brilliant purple sheen of their upperwings. Males’ wings are purplish all over, while the females only have this on the base of the forewings.

Caterpillar: March – June. The caterpillar is a distinctive reddish-brown in colour, with dark brown diagonal stripes, but they are not often seen as they feed at night and hide in leaf bases by day. The primary larval foodplants are Pedunculate Oak (Quercus robur), Sessile Oak (Quercus petraea) and Turkey Oak (Quercus cerris). Evergreen Oak (Quercus ilex) is also used.

Distribution From the UK Butterflies website:  The Purple Hairstreak is our commonest hairstreak, and may be found in oak woodland throughout southern Britain, and more locally elsewhere. It is often difficult to locate, due to its habit of flying in the tree canopy, where it feeds on honeydew. However, the adults are occasionally seen basking at lower levels, on various small trees, shrubs and bracken. This butterfly is found across southern England and Wales, with scattered colonies further north.

UK Butterflies Status:The status of this species is relatively-stable and numbers have even increased in some areas. As such, it is not a species of conservation concern.


WHITE LETTER HAIRSTREAK – satyrium w-album

Wingspan: 25-35mm Flight period :

The White-letter Hairstreak is one of our more-elusive butterflies as it flits high in the treetops, often appearing as a dark speck against the sky. It gets its name from the letter “W” that is formed from a series of white lines found on the underside of the hindwings.

Elm is the sole foodplant and this species suffered as a result of Dutch elm disease in the 1970s and early 1980s, especially in southern sites. All species of elm were affected and there was concern that this species of butterfly might become extinct in the British Isles as a result. Surviving colonies were subsequently looked for, to obtain a better understanding of the distribution of this species. Several new colonies were found which gave new hope for the future of this butterfly. In addition, there has been a concerted effort to find disease-resistant elms that exhibit the appropriate qualities to support this butterfly (such as flowering at the right time of year since young larvae generally rely on flower buds as a food source).
This butterfly forms discrete colonies which are sometimes very small containing only a few dozen individuals. Colonies are typically focused on a small clump of trees or even an individual tree. These butterflies are not great wanderers and will reuse the same site year after year. This butterfly is found throughout England, south of a line stretching between South Lancashire in the west and South Northumberland in the east. This species is found more locally in Wales, and is not found in Scotland, Ireland or the Isle of Man.

UK Butterflies Status: This species is in serious decline and is therefore a priority species for conservation efforts.


SMALL COPPER lycaena phlaeas

Wingspan 2.5-3cm Flight period: April, May, June then July, August – early September in 2-4 broods
Description: The upperside of this little butterfly is dark chocolate brown, with russet to orange spots and patches that are larger in the male than in the female. Males also have a black strip of scent scales at the middle of their forewings. The underside of both is a yellowish-brown tinged with olive green decorated with a subtle yellow pattern.
Distribution: Throughout Europe to Northernmost Scandinavia, up to 2,000m in mountains; in dry sunny unimproved meadows, cattle pastures, fallow land and other flower-rich areas where dock and sorrel grow.
Local sightings: Bryn Euryn, Bryn Pydew, Little Orme


HOLLY BLUE celastrina argiolus

Wingspan                  Flight period March to October

The Holly Blue is the first of our British blues to be seen flying in the Spring, indeed amongst the first of any species to be seen flying early in the year. It’s quite different to most other blues in appearance; it’s silvery-blue underside is marked with small black dots and has no orange and it’s also our only blue to be seen in trees where they seem to spend a lot of their time early on. They are fast fliers too, which can make them quite tricky to get a good look at.


COMMON BLUE Polyommatus icarus

Wingspan 2.7-3.4cm Flight period: Early April to mid-October in two or three broods

Upperside of male is bright, light blue with a violet tinge; wing edges are outlined with a thin black line and bordered with a white fringe. Females are brown, occasionally suffused with blue and have a row of orange spots along outer wing margins. Underside is light grey in male and light brown in female with a vivid pattern of dots in both sexes.

Behaviour: Feeds on flowers and also at damp patches on the ground. At night roosts head-down on grass stems. Female lays eggs singly on the buds or flowers of the larval food plants.
Hibernates as a half-grown caterpillar.

Distribution: Throughout Europe to the Arctic, in mountains to altitudes of 2000m+, in dry and wet meadows, in open hilly country.


SILVER-STUDDED BLUE plebejus argus ssp. caernensis

This subspecies was first defined in Thompson (1937) (type locality: Great Ormes Head, North Wales).

” Caernensis occurs at a considerable elevation on limestone cliffs near the sea; and feeds, so far as I have been able to ascertain, exclusively on Rock Rose (Helianthemum). The time of its appearance is much earlier than type argus, at any rate in Wales, often emerging as early as the second week of June. This form never flies with the type, but is confined to totally different surroundings and conditions. There are many localities for type argus in the district, but all these are situate on sandy heaths and low lying waste lands; whenever a colony is found on the cliffs it is composed entirely of caernensis. ”

This subspecies differs from the subspecies argus as follows:
1. It is smaller in size.
2. The male upperside has narrower, sometimes absent, dark borders.
3. The male underside is paler.
4. The female upperside has a blue flush that extends over most of the hindwings and base of the forewings.
Male. Very much smaller than type argus, those in my series varying between 16 mm and 22 mm when fully expanded. In colour they are much paler than the type, approaching the shade of argiolus; the black border is greatly reduced, and in some specimens almost absent.

The underside varies from chinese white to a beautiful steely grey, but all the markings are smaller than usual and the lunules dull and inconspicuous.
Female. Smaller than the male, varying from 15 mm to 20 mm. The majority are very strongly suffused with purple blue, and the upperside variation is so great that I must divide them into four sections. I allot a varietal name to each.
var. splendida. Specimens entirely suffused with blue, the brown scaling being obliterated.

Distribution: This subspecies was formerly restricted to the Great Ormes Head in Caernarvonshire, (now Conwy), North Wales. However, in 1942, 90 adults were introduced to the Dulas Valley, some 13km to the east, and the colony has gradually spread along the valley at a rate of 1km per decade, colonising 15 new sites. It is estimated that the total population now numbers 100,000.

Local sightings: My own sightings so far have been restricted to the Great Orme, but I know them to also be present on Mynydd Marian and in places around Llandulas where there are exposed limestone cliffs due to quarrying.


BROWN ARGUS aricia agestis

Wingspan 2.7-3.4cm  Flight period: Fly over open grassland May-September.

Description: Both sexes of this butterfly have brown uppersides with orange spots around the edges but with no blue at all. The undersides are a greyish brown with orange marginal spots and numerous white-ringed black dots. The two anterior dots on the hindwing are close together, forming what is described as either a colon or figure of 8. The adults have a silvery appearance as they fly low to the ground and they stop frequently either to perch or feed on flowers. They may be confused with Common Blue females, which also have brown upperwings but which usually have some blue at the base.

Habitat: The main habitats are chalk and limestone grassland. However, the butterfly can occur in a range of habitats with disturbed soils, including, coastal grassland and dunes, woodland clearings, heathland, disused railway lines and road verges.

Distribution in UK: Widespread in southern & central England as far north as Yorkshire. Less common & mainly coastal in Wales and south-west England.
Local sightings: Bryn Euryn; Bryn Pydew






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