Lepidoptera The Small Copper Butterfly – Polyommatus Phlaas
The only other British member of the genus Polyommatus-the Small Copper-is one of the commonest of our butterflies. It may be found in nearly all parts of the British Isles from April to September, more particularly in April, June, and August, for it is apparently triple brooded.
This brilliant and lively little insect is shown on 
Plate VI (fig. 9), and, being so very familiar, needs no description.
The caterpillar feeds on different species of dock-the broad-leaved dock (Rumex obtusifolius), the fiddle dock (R. pulcher), the sorrel (R. acetosa), and the sheep sorrel (R. acetosella); also on the ragwort (Senecio Jacobaa). It is full fed about three weeks after hatching, and then changes to a small and stout chrysalis, of a pale brown colour, on the leaf of its food plant.
The caterpillar itself is green, with a reddish line on the back and on each side; and it glides over the surface of the leaves something after the manner of a slug, without exhibiting any very apparent motion of its short legs and claspers.