The full-grown caterpillar is of a delicate light green, the stripe along the back is rather bluish-green, with paler green central and side lines; the spiracles are flesh-coloured, and below these there is a somewhat creamy-white stripe. The head is deeper green than the body, and roughened with minute points. It feeds in June on Holcus lanatus, Brachypodium sylvaticum, and probably other kinds of soft grasses, and its assimilation, both in colour and texture, with the blades of grass is remarkable. Before changing to the chrysalis it encloses itself within two or sometimes three leaves of the grass, joined together longitudinally by lacing or spinning with white silk, the edges more or less close to each other, and becomes completely hidden.
The chrysalis is secured in the silken chamber, head upward, by an oblique cincture behind the thorax, and the anal tip fastened by a fan-like spread of fine hooks at the extremity fixed in the silk. The colour is similar to that of the caterpillar, and the lines are fairly in evidence. Caterpillars that spun up on June 18 to 23 produced butterflies on July 15 and 16.
Hellins states that eggs were laid in a row in a folded blade of grass about July 29, and that the caterpillars hatched out on August 12.
According to Hawes, the caterpillar of this species does not hatch from the egg until the following spring.
Although it does not seem to be very plentiful in fenlands, this butterfly certainly has a partiality for damp places, whether in the rides, or on the sides of woods, on hill slopes, or waste ground. Wherever there is a fairly large growth of the taller soft grasses that the caterpillars feed upon, there the butterfly may be found in July and August throughout the greater part of England and Wales. Reported from the Edinburgh district in Scotland; and in Ireland from Powerscourt and near Cork.
Small Skipper.
Caterpillar and chrysalis.
