152 TRANSFORMATIONS OF INSECTS. 



leaves, each containing a piece of the excrement of the caterpillar, 

 are left upon the tree for a short time. When the caterpillar has 

 attained its full growth it rolls up a leaf longitudinally into a 

 light tube, spins its cocoon, and changes into the pupa. There 

 are two broods in the year. 



The pupae of the genus Ncpticula have the parts of the 

 future insect far more conspicuously displayed than is usual in 

 the chrysalides of the Lcpidoptera ; and Ncpticula anovialella 

 may be found in the hollow of the footstalk of the rose leaf 

 which the caterpillar has marked with serpentine tracks in the 

 later weeks of the summer. It is contained in an elliptical 

 reddish silken cocoon. 



The perfect insect lays its eggs on the under surface of 

 the rose leaf, close to the mid-rib, and the larva, when hatched, 

 bores into the cellular structures, and commences an irregular 

 wavy gallery. When fully formed the larva splits the upper 

 skin of the leaf, and creeps out ; and if it be one of the 

 summer brood it proceeds to the leaf stalk, and there spins 

 an orange coloured cocoon, which is of rather peculiar structure; 

 for the side exposed to the weather has a sort of outer covering 

 which projects beyond the limits of the true cocoon, serving as 

 a protection against the wet. If the larva be of the autumnal 

 brood, it very rarely seeks the foot-stalk, but attaches itself 

 to the main stem of the rose bush, beneath the shelter of some 

 branch or thorn, or else it seeks shelter on the ground amongst 

 leaves. After completing the cocoon, the metamorphosis into the 

 chrysalis takes place, and the second transformation occurs in a 

 fortnight or three weeks in summer, and in six or seven months 

 in winter and spring. 



Some of the mining genera of the Tincina undergo very rapid 

 transformations, and the kinds oi Lithocollctis which fly in July and 

 September offer examples. They are very small moths, with hairy 

 heads and straight and pendent palpi, and their wings, which 

 arc of different colours, are frequently ornamented with spots 

 looking like gold or silver, and have beautiful fringes. Moreover,, 

 the antenncc, which are like slender threads of silk, are kept in 

 constant movement. There are at least a hundred species of 

 this genus, and each one lives upon some particular plant ; but 



