48 



BIRDS IX THEIR RELATIONS TO MAN. 



face of the cabbage, eating more and more as Lliey develop. 

 When fully grown each spins a slight silken loop on the 

 cabbage-leaf or some near-by shelter, generally on the lower 

 surface, and changes to a pupa or chrysalis. In a short time 

 it emerges as a butterfly. 



A large proportion of the caterpillars of tlie Lepidoptera 

 are eagerly devoured by birds, forming an important element 

 of the food of many species. Mention can be made here of 

 only a few of the more important families. 



There is a large family of small moths called Tortricidw^ the 



larvae of Avhich are com- 

 monly known as '' leaf- 

 rollers."* The normal 

 habit of these little cater- 

 pillars is to feed upon the 

 surfaces of leaves which 

 they roll into a protective 

 covering; sometimes they 

 live singly and sometimes 

 a mnnber live together in 

 a common nest. Insects 

 of this family attack the 

 leaves of nearly all our 

 fruit and ornamental trees, 

 although, fortunately, they 

 generally do little damage. 

 Some species are not con- 

 tent with the foliage, but 

 feed u}j()n the fruit ; the 

 too well-known codling- 

 moth, or apple-worm, is 

 an example of this group. 

 The larva\ i)Up;e. and moths of the leaf-roller family are all 

 eagerly devoured by birds, but these insects are greatly pro- 

 tected by their habits and colors, so that probably birds do 



•F AIM'I.K I.KAF-MINKK. 



