A common butterfly, the Speckled Wood can be expected wherever woodland rides and edges provide some shade with dappled sunlight. The butterfly's spotted pattern seems almost to reflect the dappled light conditions that it favours. These butterflies may be found in large gardens with mature trees and long grass.
The larvae are grass feeders, particularly on coarser grasses.
The first butterflies emerge in April and May from the chrysalis. Later emergences extend the egg-laying period to ten weeks or more and successive broods are produced throughout the summer until October. The butterflies may therefore be found during the entire spring and summer. In autumn, some larvae pupate and remain as pupae until spring, others continue as larvae through the winter, sometimes feeding but mainly in a state of semi-hibernation, finally growing and pupating in March and April. This is the only British species that hibernates either as a larva or as a pupa, almost according to choice.
In the British Isles the Speckled Wood is the sub-species egerides. The type (Pararge aegeria aegeria) has spots of orange brown instead of creamy white, and this type form is found commonly across most of the rest of Europe. Such orange forms found in Britain, however, are more likely to be aberrations of egerides than examples of aegeria aegeria. When the butterflies hold their wings open it is not too difficult to distinguish the sexes. The wings of the female are more rounded, and a surer distinction is that the male has a broad patch of darker, velvety scent scales across the forewings. In some lights these are a reflective, almost golden, colour instead of dark, as the light catches the hairs. Summer-brood butterflies have larger paler spotting. The eggs are laid singly on the blades of grasses. The larvae hang up amongst grass and undergrowth to pupate, hanging from the tail.