202 ELEMENTS OF COMPARATIVE ZOOLOGY. 



have left a vegetarian diet and taken to food of animal or- 

 igin. Another exception is found in the bee-moth, the larva 

 of which is found in apiaries, feeding upon the wax and 

 spinning its silk all through the comb. 



Of the leaf-rolling moths the codling-moth is the best 

 known. Its larva is the worm so frequently found near 

 the core of apples. Other allied species tie the leaves of 

 apple-trees, roses-bushes, etc., together and live in the nest 

 thus formed. 



The Geometrids include those moths whose larvae are com- 

 monly known as measuring-worms from their looping gait. 

 All of these are pests, and the canker-worms exceed all the 

 rest in this respect. These are especially noticeable from 

 the fact that the adult female is wingless. 



The sphinx-moths or hawk-moths are large narrow- winged 

 forms, the larvae of which are injurious to many plants. 

 From the attitude assumed by some larvae when at rest the 

 name sphinx was applied to the group ; the other common 

 name, hawk-moths, has reference to their powers of flight. 



FIG. 87. Sphinx-moth (Everyx myron). From Riley. 



Another group of moths are known as Bombycids. While 

 some of these are unmitigated pests, others are of value to 

 man, the silkworms leading in this respect. These are, in 

 fact, the most valuable of all insects. The true silkworm is 



