Biology

The speckled wood can be seen in dappled sunlight in woodlands. The male tends to perch in patches of sunlight, and intercepts intruding butterflies. They may also patrol an area in search of females. This species does not usually feed on flowers but males and females feed on honeydew produced by aphids up in the tree canopy (4). There are typically three generations per year, but in Scotland there is usually just two. The flight-periods of the adults of each generation overlap, so they can be seen from March through to October (4). Females lay their eggs singly on leaf blades of the foodplants (Cock's-foot Dactylis glomerata, couch-grass Agropyron repens and annual meadow-grass Poa annua). The caterpillars, which hatch after around ten days, feed at night or during the day (3). They are very well camouflaged against the blades of grass, thanks to their green colouration (4). Pupae form attached to the foodplant or to vegetation nearby. The speckled wood can overwinter either as a caterpillar or as a pupa, an unusual situation in a butterfly.