Blues & Coppers (Family Lycaenidae)

Descriptions & images of the 7 species of Blues and 1 Copper resident in Hampshire.

The Blues and Coppers belong to our largest family of butterflies - Lycaenidae - which also includes the Hairstreaks on the next page. Butterflies of this family contain some of our brightest coloured species, as you will see when you work down the page. These butterflies tend to be colonial, ranging from a few individuals in the case of the Small Blue, to hundreds in the case of the Chalkhill Blue on some large sites.

Occurrence (distribution based on 1km squares) and abundance (total population) trend data, extracted from the report "The State Of The UK's Butterflies 2015" published by Butterfly Conservation, is shown for each species and indicates the change in distribution and population during the last four decades (1976 - 2014) at UK national level. 

Adonis Blue - Polyommatus bellargus

 Wingspan:~30-40mm

Distribution change 1976 - 2014: -6%, Population change 1976 - 2014:  +175%

 

There are no words and certainly no photograph which can really do justice to the vivid electric blue of the male Adonis Blue, the colours varying through different hues as the observation position changes or the butterfly manoeuvres its stance. The female Adonis Blue is mainly brown with a dusting of blue scales close to the body. The Adonis Blue is at the edge of its range in Southern England (up to S Midlands), so it's not surprising that it favours sunny south-facing slopes, where the turf is short on chalk or limestone hillsides. It also needs a plentiful supply of the larval foodplant which is exclusively horseshoe vetch. Whilst neighbouring counties of Wiltshire, Dorset and Sussex together with the Isle of Wight are considered strongholds of the Adonis Blue, Hampshire has only a few sites which meet the butterfly's stringent demands.

When to see: Two generations per year, the first from mid-May, the second from mid or late August. In Hampshire, because colonies are small, flight periods are short, typically 2 or 3 weeks.

Where to see: Martin Down National Nature Reserve in the far west of the county is the most reliable site in the county for this species, followed by Old Winchester Hill, where successful management has seen the Adonis population strengthening. There are also a number of small and potentially vulnerable colonies, including at Broughton Down and St Catherine's Hill. 

Brown Argus - Plebeius agestis

Wingspan: ~25-30mm

Distribution change 1976 - 2014: +115%, Population change 1976 - 2014: -25%

 

The Brown Argus in almost every respect is the archetypal "blue" butterfly (family, size, wing pattern, behaviour....) except for one thing - it's colour! There are no blue pigment wing scales on either sex, although freshly emerged specimens can have a slightly bluish hue, due to diffraction. The butterfly is widespread in the south-east quadrant of England, including Hampshire. Its main habitats are on the rough ground on dry hillsides and chalk downland, where the larval foodplant - common rock-rose - is plentiful. The butterflies are low flying, stopping frequently to take nectar from flowers or to bask. Identification can be difficult since the females of many other blue butterflies are brown or predominantly brown, and the Brown Argus can be found in company with other blue species. A good guide is its silvery-grey appearance when in flight (resulting from the underwing colouration) which is characteristic of no other blue, but there are also subtle differences in markings which I will not attempt to elaborate here. 

When to see: There are two generations per year, the first commencing early May lasting around 4-6 weeks, the second in mid-July lasting until early September.

Where to see: The Brown Argus is not a species that is usually seen in large numbers, compared to some of the other blue species (e.g. a few sightings at a location is more typical). Sites where it can be found include Noar Hill, Broughton Down, Magdalen Hill Down and Stockbridge Down.

Chalkhill Blue - Polyommatus coridon

Wingspan: ~ 32-40mm

Distribution change 1976 - 2014: -50%, Population change 1976 - 2014: +20%

 

As the name, suggests, the Chalkhill Blue favours chalk downland, mainly in Southern England and into the Midlands - and where suitable habitat exists, preferably on unimproved downland, it can be very numerous with scores or even hundreds on the wing. However, in recent years, populations have been known to slump unexpectedly at formerly good sites. Whilst the male Chalkhill Blue is a pale powder blue, the female is characteristically brown, with a row of orange spots around the wing edges. The foodplant of the Chalkhill Blue is (as for the Adonis Blue) horseshoe vetch, however, the Chalkhill Blue favours slightly longer downland grass than the Adonis, and is more widespread. 

When to see: There is one generation per year, with the flight period starting in early July, through until mid-September. Early August is probably the optimum time to see this species in large numbers.

Where to see: There are several good populations in Hampshire including Old Winchester Hill, Martin Down, Magdalen Hill Down, Stockbridge Down, Portsdown Hill and Oxenbourne Down, noting the comment above that populations do occasionally slump unexpectedly.

Common Blue - Polyommatus icarus

Wingspan: ~29-35mm

Distribution change 1976 - 2014: -17%, Population change 1976 - 2014: -17%

 

By far the UK's most widespread blue butterfly, although ironically not as "common" as it used to be. It can be found on rough ground, downland, meadows and clover fields to woodland clearings - where its various foodplants grow. These include bird's foot trefoil, black medick and various clovers. The butterflies are active, making rapid but usually short flights from flower to flower. The females are usually predominantly brown, but with some blue scales close to the thorax, ranging to a more significant area of blue, as seen in the last slide above. 

When to see: There are two generations per year, with the flight periods being from mid-May until the end of June and again from mid-July until mid September.

Where to see: Almost all downland sites have decent colonies including Old Winchester Hill, Stockbridge Down, Magdalen Hill Down and Portsdown Hill. Noar Hill also has a reasonable population.

Holly Blue - Celastrina argiolus

Wingspan:~27-35mm

Distribution change 1976 - 2014: +39%, Population change 1976 - 2014: +37%

 

The Holly Blue is a widespread species in most of England and Wales, but populations of the butterfly can be very variable due to its vulnerability to parasitic wasps. As the name suggests, it is a species associated with holly which is one of the larval foodplants of the spring generation. This species is often encountered in one's or two's rather than in colonies, due to their habit of wandering, typical places being woodlands, hedgerows, parks, gardens and even churchyards. The underside of the butterfly has few markings, giving it a distinctive appearance in flight compared to other 'blues'.

When to see: There are two generations per year. It is normally the first blue butterfly on the wing, the first generation emerging in early April through till late May, the second in late July, though until early September. In warm years there are sometimes a few records of third-generation insects in Autumn.

Where to see: Since the butterfly can be encountered almost anywhere in the places described above, there should be no need to go far to see it in Hampshire. I have seen Holly Blues often at Noar Hill, on Portsdown Hill and in Whiteley Walks as examples of different "natural" habitats, as opposed to parks and gardens.  

Silver-studded Blue - Plebeius argus

Wingspan: ~26-33mm

Distribution change 1976 - 2014: -64%, Population change 1976 - 2014: +19%

 

The Silver-studded Blue is a very local species and its national distribution is in decline. In the south of England it is associated with heathland habitats, but elsewhere can be found also on sand-dunes. Although local, where it is found it can be very numerous. The males have a purplish blue upperside with brown outer edge, whereas the females are mainly brown on the upper surface. Unusually the males are often slightly larger than the females. The flight is low and fluttering rarely more than a few yards. The larvae feed on the leaves of heather or cross-leaved heath but can also feed on bird's foot trefoil and horseshoe vetch.

When to see: There is one generation per year from mid-June through until mid-August, however the flight period can vary by a week or more according to site ecology.

Where to see: The butterfly is quite widespread on the New Forest heaths including Beaulieu Heath. There are also good sites outside the forest at Silchester Common and Hazeley Heath in the north of the county and also Broxhead Common in the east. 

Small Blue - Cupido minimus

Wingspan: ~17-27mm 

Distribution change 1976 - 2014: -44%, Population change 1976 - 2014: +9%

 

The Small Blue is our smallest species inhabiting rough grassy slopes, sheltered grassy hollows and quarries, usually in chalk or limestone-rich areas. It also has a prerequisite for the larval foodplant, kidney vetch, to be in good supply. The Small Blue is a very local species, colonies being found in the same few square yards year after year and nowhere else for miles around. Sadly this lovely little butterfly is also in distribution decline nationally.  If you have not seen Small Blue before, you may be surprised just how small they are, especially the male - fresh ones being perfection in miniature. The male also has a dusting of blue scales close to the body which is absent in the females. The flight is slow and fluttering and when disturbed they usually fly around rather than away, but can still be difficult to follow because of their small size.

When to see: Two generations per year, the first commencing mid-May for about one month, the second smaller generation commencing mid-July, with a flight period of just 3 weeks.

Where to see:  Martin Down and  Magdalen Hill Down are good sites. There are also a few other colonies around the county including Portsdown Hill. Populations can vary significantly from year to year.

Small Copper - Lycaena phlaeas

Wingspan: ~25-36mm

Distribution change 1976 - 2014: -16%, Population change 1976 - 2014: -37%

 

An attractive and unusual butterfly with its bright copper-red colouring, the Small Copper is also widespread, facilitated by the variety of its habitats. These range from rough grassland, downs and meadows even to woodland glades and clearings, where its larval foodplants of the sorrel family can be found. The butterflies fly swiftly and directly but normally only a few yards at a time, the males sometimes returning to the same perch.

When to see: There are usually 3 generations per year, the first from early May until mid-June, the second from early July until late August and the third in mid or late September lasting only 2-3 weeks.

Where to see: The butterfly can be encountered at many sites but usually only in small numbers. Sites include Noar Hill, Browndown (S), Portsdown Hill and Old Winchester Hill.

© Copyright Alan Thornbury's Hampshire Butterflies 2020