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