Small Heath, Coenonympha pamphilus
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Identification
Smallest brown butterfly, 35mm to 40mm.
Both sexes are very seldom seen with its wings opened at rest. The upper surfaces of the wings are a warm golden brown with a dark eyespot towards the tips of the forewings and the outer margins of the wings are edged a darker dusky brown. There is a paler yellow brown patch in the centre of each hindwing. The underside of the forewings are similarly colour-patterned to the upper surface but the eyespot is more complex with a white inner dot, surrounded by a black ring which, itself, is surrounded by a pale yellowish ring. The underside of the hindwing is basically greyish with a paler cloud half way along its length and a series of six indistinct brown rings towards its outer edge.
Behaviour and life history
The Small Heath is an inconspicuous butterfly, spending much of its time resting up with its forewings hidden inside its cryptically colour-patterned hindwings. It is to be found wherever there is a fairly fine grass sward in which it establishes small colonies. In Plymouth it is generally only seen in low single figure numbers. The butterfly overwinters as a caterpillar, pupating in late spring before emerging as an adult in May/June. Eggs are laid immediately and after a short developmental period, second brood adults appear from late July onwards.
Where to look for it
The Small Heath is a butterfly of shorter, finer grass swards and is most plentiful on sheltered, poor grassland on well-drained slopes. However, it can turn up almost anywhere and also favours sunny hedgebanks, verges and woodland glades.
Distribution and status
Records would indicate that it not a particularly common butterfly in the city but this may well, in part, be accounted for by its inconspicuous behaviour. It is most common around the lower Plym estuary on the limestone grasslands and in adandoned quarries.
When to look for it
It is most frequently to be seen in May and June although smaller numbers, from the second brood, are around in July and August.
Similar species
This is the smallest local brown butterfly which is unlikely to be confused with the larger brown butterflies. The greyish colour-patterned underside of the hindwings with the series of six darker rings should be sufficient to confirm its identity.