One of the butterflies that I most associate with my youth is the Speckled Wood (Pararge aegeria). I remember seeing lots of them sunbathing on bramble leaves as I picked blackberries. They seemed to love the patches of sunlight on the hedges at the edges of woods – just the places that blackberries grew. Although there are fewer butterflies around now as the weather gets cooler and the blackberries are over, you still see a few. It seems that, if the weather is getting warmer, our climate changes are suiting this native butterfly and numbers are actually increasing.
It is a rather unusual butterfly and actually prefers wooded areas to open grasslands or gardens because it rarely feeds on flowers, preferring to feed on the honeydew dripped by aphids on trees such as lime (tilia). It is only when there are few aphids around, at the end of summer, that they change their feeding habits and bother with flowers. So it is more a butterfly of rural than urban areas. The green caterpillars feed on grasses, especially cocksfoot (Dactylis glomerata), Yorkshire fog (Holcus lanatus) and couch grass (Elytrigia repens) – nice to know something eats it!
There are several generations a year so there is a peak in adults flying around in early summer and again in late summer. The males and females are superficially similar. The males are very territorial and both sexes spend the night high in trees, the males finding a sunny spot in the morning and protecting it. If another male comes along the first will fly after it and tussle for position, returning to the spot if it wins. If a female comes along the male will fly after her and they mate in the grass. Each female usually only mates once.
The Speckled wood is found throughout the British Isles except in the far north of Scotland although it is expanding its range. It is not found in upland areas, presumably because of the lack of the necessary trees.