SlfcE. 



It is not unreasonable to suppose that a smaller insect requiring less 

 food and able to live long- periods on little nourishment thrives where a 

 larger insect could not. Probably it can reproduce more rapidly/ it 

 offers less inducement to enemies, arid on the whole may be more suc- 

 cessful. These considerations probably determine the limit of size and 



FIG. 43. 

 The Oleander Hawk Moth : one of the swiftest -fly ing of the large moths of India. 



the average is far lower than is generally supposed. Large insects are 

 rarely so injurious or plentiful as small ones. Locusts of course are an 

 exception. The very large ones cannot perhaps multiply sufficiently fast, 



FIG. 44. 

 The Red Borer of Coffee i caterpillar; pupa, as it wriggles out of the li anch ; moth. 



