The small tortoiseshell, considered to be our commonest native species of butterfly, is currently taking nectar from late garden flowers before hibernating. With wings closed, it looks like a dead leaf, but open, it is particularly colourful and a swift flyer.
Often they need to be released from closed windows, particularly when they awake in the spring. Many die because they cannot escape.
The survivors mate and lay eggs in batches of 60 to 100 on tender young nettles. Caterpillars hatch after 10 days and cluster on webs of silk; they are bristly and black with two broken yellow lines along their sides. There are two broods in a year, and butterflies are on the wing in most months.
Continental specimens join us in late summer. On September 10 I observed caterpillars on nettles along the Brue, which could mean a third brood if they survive.
We used to have a large tortoiseshell, but it is now extinct in this country. I last saw specimens on the wing at Westerham, Kent, during the war.