250 CONSIDERATIONS FROM STUDY OF INSECTS 



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tection are seen when we examine insects in their native haunts. 

 We have noted that various animals, such as the earthworm 

 and crayfish, escape observation because they have the color 

 of their surroundings. Insects give many interesting examples 

 of protective coloration or protective resemblance. The grass- 

 hopper is colored hke the grass on which it fives. The 



katydid, with its green body and 

 wings, can scarcely be distingmshed 

 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. 



One example frequently quoted is 

 the dead-leaf butterfly of India. 

 This insect at rest resembles a dead 

 leaf attached to a limb ; in flight, be- 

 cause of its vivid colors, it is con- 

 spicuous. The underwing moth is 

 another example of a wonderful sim- 

 ulation of the background of bark on 

 which the animal rests in the daytime. 

 At night the brightly colored under- 

 wings probably give a signal to others 

 of the same species. The beautiful 

 luna moth, in color a delicate green, 

 rests by day among the leaves of the 

 hickory. The small measuring worms 

 stand out stiff upon the branches on 

 which they crawl, thus simulating lateral twigs. Hundreds of 

 other examples might be given. 



This likeness of an animal to its immediate surroundings has 

 already been noted as 'protective resemblance. 



Aggressive Resemblance. — Sometimes animals which resemble 

 their surroundings are thus better able to catch their prey. The 

 polar bear is a notable example. Some insects are thus colored. 

 The mantis, shown in the figure, has strongly built forelegs, with 

 which it seizes and holds insects on which it preys. The mantis 



The underwing moth ; above 

 flying ; below, at rest on bark. 



