HOW ARE INSECTS PROTECTED? 



81 



hundreds of forms that 

 live on weeds and decayed 

 food, and they have nu- 

 merous ways of escaping 

 their enemies. Such is the 

 house fly. On the other 

 hand, such insects have 

 many enemies so that few 

 forms become over abun- 

 dant. Many can fly and 

 thus have an easy way of 

 escaping their enemies. 

 Then many species are 

 very tiny, thus escaping 

 detection. The fact that 

 many species pass through 

 a metamorphosis is an un- 

 doubted advantage, for 

 often there is a long qui- 

 escent stage either passed 

 out of sight in the ground 

 or under bark of trees or 

 stones. The pupae of 

 many insects are covered, 

 so that birds or their ene- 

 mies would not notice them. Many adults have either a hard body 

 covering or are covered with hairs. In addition many have odor 

 or taste disagreeable to birds, which are their chief enemies. 



If we examine insects in their native haunts, we find that many 

 of them have interesting means of protection. The grasshopper 

 is colored like the grass on which it lives. The katydid, with 

 its green body and wings, can scarcely be distinguished from the 

 leaves on which it rests. The walking stick, which resembles the 

 twigs on which it is found, and the walking-leaf insect of the tropics 

 are other examples. This is called protective resemblance. 



Some insects are provided with means of defense, such as poison 

 hairs or stings. Those animals which are harmful are sometimes 



■^ _^ 



if 



C. Clarke 

 The viceroy butterfly (above) mimics the monarch 

 butterfly, which is distasteful to birds, and thus gains 

 protection from its enemies. 



