A late-season speckled wood (Pararge aegeria) photographed last week, basking in the sunshine on the edge of the copse between Sleeper Field and Sheep Field. They are creatures of such woodland edges, camouflaged by the dappled light.
Speckled woods usually feed on honeydew in the treetops; they are rarely seen feeding on flowers except very early in the spring or very late in the autumn when there are few aphids around to make any honeydew. The caterpillars feed day and night on several species of grass: false brome, Yorkshire-fog and common couch. The park’s field margins and set-aside are ideal for speckled wood caterpillars.
 A late season adult speckled wood feeding on hogweed;  speckled wood larva feeding on grass.
This species is unique among British butterflies: it can overwinter in two different stages, as either a larva or a pupa. The hibernating larvae or pupae hide on the underside of blades of grass, low down in the sward, where the temperature fluctuates least.
As a result of this dual-method hibernation, there are adult butterflies on the wing from as early as March right through to September, with a few adults, like this one, being seen as late as the middle of October, especially at southern sites. Each summer produces two or three generations of adult butterflies, depending on the location and weather conditions.
The speckled wood is also exceptional among British butterflies because its population has increased by 85% in the last forty years and the species has experienced a 70% increase in distribution. This is believed to be the result climate change. As the UK’s climate has warmed, the butterfly has colonised East Anglia, the Midlands and much of northern England, a welcome success story among reports of our generally declining Lepidoptera.
Two of DKG’s photographs of late season speckled woods
Butterfly Conservation priority: Low.
European status: Not threatened.