306 



THE SCHOOL GARDEN. 



There are longitudinal yellow bands. The skin is warty, 

 with short whitish hairs. Two genera- 

 tions of this caterpillar occur in the year, 

 in June and July and in September, 

 consequently we may find both summer 

 a,nd winter chrysalids. (The chrysalis is 

 angular, greyish green, with black and 

 yellow markings. It occurs fixed, usually 

 in a horizontal position, to walls, under 

 roofs or doorways, etc.) (Fig. 164.) 



Caterpillar of the small white butter- 

 fly : Pier is rapae. This caterpillar, which 

 also occurs on the cabbage leaves, is 

 about 1J inches when fully grown. It 

 is of a dull velvety green above, paler 

 below. There is a deep orange line along 

 the back, and orange spots on the sides. 

 In this case the eggs occur separately. 

 There are two generations here also. 

 The magpie moth caterpillar has al- 



Fig. 164. -Caterpillar re ady been described (p. 153). 



Sometimes beside a dead caterpillar or 

 the chrysalis of the large white butterfly 



may be noticed a heap of small yellowish cocoons. These 



are the cocoons of an 



Ichneumon fly (Micro- 



gaster glomeratus) which 



deposits its eggs inside 



the body of the cater- 

 pillar. The larvae feed 



upon the substance of 



the caterpillar and are 



ready to become pupae 



about the same time. 



They bore through the 



skin and pupate. The 



caterpillar usually dies ; 



even if it should succeed 



in entering the pupa 



stage, the adult butterfly is not formed (Fig. 165). 



and Chrysalis of the 

 Cabbage Butterfly. 



Fig. 165. The Ichneumon Fly of the Cabbage 

 Butterfly, magnified. 



