198 THE BOOK OF BRITISH BUTTERFLIES. 



and it almost seems that the earlier one affects holly- 

 blossoms, while the latter prefers to feed on the ivy. 

 The first flight of butterflies occurs at the end of 

 April and in May. The eggs are laid on the holly, 

 and the larvae feed on the flower-buds, young berries, and 

 young leaves. They are full-fed in about a month, and 

 the pupae, which are fastened to the leaves, come out 

 in about eighteen days. The second flight occurs in 

 July or August The second brood of larvae feeds for 

 about forty day in August and September, the winter 

 being gast in the pupa stage. 



The full-grown larva (Fig. 228) is about $in. long, and 

 of the usual Lycana shape. It exhibits considerable 

 variation as regards colour. One form is green with a 

 paler streak on the dorsal ridges and thin, double, 

 oblique lines on the sides, with a yellowish-white 

 margin to the sub-spiracular dilatation. The head is 

 almost black. The round spiracles may be described as 

 flesh-coloured, and the skin is covered with yellowish 

 warts each emitting a white hair. The green of the 

 ground-colour varies, and some individuals are marked 

 with pink or black. The food-plant has something to 

 do with these differences. While the larva is not feeding, 

 and waiting for the pupal change, the colour becomes 

 greyish-pink. 



The pupa, which is about sin. in length, is stout and 

 has on the dorsal surface of the thorax the slightest 

 trace of a keel ; the wing-cases are long. The colour is 

 pale brownish-yellow, except the wing-cases which are 

 grey. These latter are smooth, whereas the rest of the 

 body is covered with tiny brown hairs. The markings 

 are a dark-brown line on the back of the thorax, which 

 is continued down the abdomen as a series of dashes. 

 The abdomen also bears a sub-dorsal series of larger 



