Small Copper

Small Copper Lycaena phlaeas (Linnaeus 1761)

Family: Lycaenidae, subgroup Lycaeninae (The Coppers)

Description


The Small Copper is a small, very active and fast flying butterfly with bright reddish copper-colouredupper forewings with black spots and margins. Hindwings are dark with black-spotted lower margins. Females are slightly larger than males with more rounded forewings and narrowercopper-coloured hindwing bands. The abdomen of females is larger than males.

This species very easy to identify because it’s so distinctive and really conspicuous when at rest with its wings open. It often basks on lowherbage or open ground. It’s easily overlooked in closed-wing view, as the drab brown colours of the underside provide camouflage.

It also has a very characteristic flight pattern which help with identification; it flies fast and erratically and is incredibly difficult to follow, often zooming high and barrel-rolling down a glade. In flight it looks light brown or sometimes gingery in sunshine. Males show aggressively territorial behaviour and carry out super-fast intercepts of interlopers, before returning to the same flower to perch.

It is unusual because it is a very variable species with over 140 described aberrations, several of which occur regularly. Some notes on the variations are set out at the end of this section.

Habitat

The species’ preferred habitat is upper moorland over around 300 metres above sea level. Other examples of preferred habitat include railway embankments, disused rail tracks, riverbanks, cliffs, meadows, disused quarries, roadside verges and patches of waste ground. The species is fairly mobile and can turn up almost anywhere including parks, gardens and cemeteries. In fact the Small Copper has become a species increasingly found on brownfield sites. However wide woodland rides are also popular with adults.

The preferred vegetation for adults is low vegetation such as heather, scrubby grass or low bracken with clearings. The adults cluster round flowers of daisies on lower land, or ragwort or yarrow on moorlands.

Sorrel (Rumex acetosa), especially sheep's sorrel, is the main larval food, and sorrel growth in sunny areas with short vegetation and bare patches of ground is good for this species. The practice of burning patches of heather moorland appears particularly beneficial in that it promotes the growth of Sheep's Sorrel as a colonising plant of bare areas. In many ways the Small Copper is dependent on periodic land disturbance as its foodplants are amongst the first colonisers of bare patches of ground.

Distribution


Populations fluctuate extremely widely from year to year, with warm, sunny and fairly dry conditions being advantageous, but cold, wet, or drought conditions, disadvantageous but, although weather no doubt play a part, nobody really seems to know why these booms and drops occur. It’s certainly one of the major mysteries of this species and could be partly due to parasites. Certainly the autumn batch of caterpillars are particularly heavily parasitised by theBraconidCotesia cupreus which is a specialist parasitoid of Coppers, but this is very poorly studied.

2020 was a particularly good year with very high counts on Grinton Moor and surrounding moor areas.In several cases over 40 adults were seen, sometimes split between colonies only a few yards from each other. However most Yorkshire colonies are small with two to 10 or 12 individuals.

Overall the species is widely distributed in the British Isles except in the highest areas of Northern England and Scotland, and the Western Isles of Scotland. lt is probable that the overall British distribution has not altered significantly over the last 200years but given the remote nature of the preferred habitat it is difficult to get a clear picture of the species distribution. There may well be many more large colonies that have not been found yet. However, although difficult to quantify, it seems that the overall population trend has been downward over the last 100 years, largely as a result of habitat loss.

Life Cycle

There are two or three broods, with a partial third appearing in good years. Occasional November records raise questions as to the possibility of a fourth brood. In Yorkshire the two or three broods tend to overlap giving the impression of a continuous flight season from April or May through to October.

The broods appear broadly as follows:

April/June, July/August, September/October

The first Yorkshire sighting in 2019 was 13 March in Scarborough

The last Yorkshire sighting in 2019 was 28 October in Hatfield, Doncaster

The eggs are white and look like miniature golf balls. They are laid on the underside of food plant leaves and hatch after seven to 14 days. In spring, females show a preference for larger plants up to 30cm, whilst in summer much smaller plants are preferred.

The slug-like green larvae are often edged and lined in purple helping them to merge into the colours of the food plants. They pupate after 25 to 30 days becoming brown dumpy sacs hanging from vegetation by silken pads. This stage, lasting about a month, is rarely observed in the wild because they are very hard to spot. Larvae from eggs laid by summer or autumn brood butterflies remain as larvae throughout winter and continue to feed when mild, but become dormant during cold spells. They usually begin to feed more actively in March and pupate later that month to emerge as adults from early May onward. Recent years have seen an increase in April sightings of adults and even the occasional March appearance.


Status

The species is not under threat.

Aberrations

The most common aberration, certainly in Northern parts of Yorkshire isab caeruleopunctata Ruhl, which has blue spots on the upper edge of the hindwing. The number and size of the blue spots varies a great deal from one or two tiny spots to the whole hindwing having a blue tinge. This is particularly common in Swaledale and what is noticeable is that adults with the blue spots appear to be in separate colonies and mate mainly with each other, even if they are alongside a group without the blue spots.

The most striking aberration, but not generally seen in Yorkshire, is the white form ab schmidtii Gerhard or ab alba Tutt, in which the copper-coloured areas are replaced with white. This is thought to occur where colonies are in-bred having been founded by single females. As a result the white forms tend to recur from year to year until thecolony receives new blood. Somewhat less striking is ab cuprinus Peyerimhoff, which is apale variety; and easily overlooked and ab radiata Tutt, where the copper hindwing band is replaced by streaks.

There are many racial variations across the whole of the range including eleus (Fabricius 1798) in Britain and hibernica Goodson 1948 in Ireland.

With thanks to the Butterflies of Yorkshire by Howard M Frost

Catherine Jones 10/11/2020