Speckled Wood Butterfly
This attractive butterfly is the northern form of a species belonging to the large family of Browns or Satyridae. It’s by far the easiest of the family to recognise. The brown upper wings have an unmistakeable slightly chequered pattern of creamy-yellow spots; the underside of the forewing is similar but paler. It has the family’s characteristic dark eyespots, one on each forewing, and three ringed with cream on the hindwings. Males and females are similar in appearance, although the female is slightly larger and has brighter yellow markings. The larvae (caterpillars) are green, tapering slightly at each end, with a forked tail.
The adults feed mainly on aphid honeydew. The caterpillars eat grass, and are apparently particularly fond of Couch Grass, so definitely to be encouraged if you’re lucky enough to find them in your garden.
The butterflies don’t seem to hibernate, but can overwinter as either chrysalis or caterpillar. With two generations in a year, new adult butterflies emerge over a long period, and the species’ flight time lasts from March to October. They are regularly seen at St Nicks from May to September, with an earliest recorded sighting of 20th April (2011) and latest 17th October (2012).
Although as the English name suggests, they are often found in areas where dappled sunlight filters through trees, the species seems to be reasonably adaptable and is one of the few known to be extending its range. Here at St Nicks you might come across them almost anywhere. In warm weather they like to bask in the sun on woodchip paths (as in the photo above), where you will sometimes get a really close view if you can penetrate the very effective camouflage.
The males are apparently very territorial and will compete for a sunny spot where they can attract passing females. Don’t assume that two Speckled Woods dancing in the sunlight must be mating!
Paul Whalley The Mitchell Beazley pocket guide to butterflies, Mitchell Beazley 1981