PLANT-EATING INSECTS 213 



food, they rely largely upon the exudations of plants, or 

 of other insects. Not only aphides, but certain scale 

 insects and other members of the sub-order Homoptera 

 provide secretions of which ants are very fond. 



Nectar and pollen form the staple food supplied by 

 bees to their young ; but these sweet and delicate sub- 

 stances are rarely sought after by nomadic larva?. Indeed, 

 to profit by the dainty banquets which the flowers pro- 

 vide, an insect must be gifted with exceptional qualifica- 

 tions. Thus we find that most flower-frequenting species 

 possess, in addition to their highly specialised mouth-parts, 

 unusually large eyes and brains ; while their muscular 

 control is remarkablv sustained and delicate. The inter- 

 relations of insects and flowers are so complex, however, 

 that we must deal with them in a separate chapter. 



