252 CONSIDERATIONS FROM STUDY OF INSECTS 



Another butterfly, less favored by nature, resembles the monarch 

 in outward appearance. This is the viceroy (Basilarchia archippus) . 

 It seems probable that in the early history of the species called 

 viceroy some of this edible form escaped from the birds because 

 they resembled in color and form the species of inedible monarchs. 

 These favored individuals produced new butterflies which re- 

 sembled the monarch more closely. So for generation after genera- 

 tion the ones which were most like the inedible species were left, 

 the others becoming the food of birds. Ultimately a species of 

 butterflies was formed that owed its existence to the fact that it 

 resembled another more favored species. In this way nature selects 

 the animals which can exist upon the earth. Many other examples 



of mimicry may be found 



among insects; one of the 

 easiest to find is the locust 

 borer, shown in the Figure. 

 Some flies imitate bees, and 

 thus escape capture. 



The chief insect enemies 

 are the birds, and from these 

 the most effective protection 

 seems to be hairs on the 

 body. Few birds eat hairy 

 caterpillars of any species; fortunately, however, the hairy 

 larvae of the gypsy moth, a serious pest, are eaten by no less than 

 thirty-one species of birds. The odors or ill flavors of insects seem 

 to be generally protective, but stinging insects do not appear to be 

 protected from all birds, flycatchers and swallows habitually feeding 

 on the bees and wasps. 1 



Communal Life among Insects. Insects are of especial in- 

 terest to man because among certain species a system of social 

 life has arisen comparable to that which exists among men. In 

 connection with this communal life, nature has worked out a 

 division of labor which is very remarkable. This can be seen in 

 tracing out the lives of several of the insects which live in com- 

 munities. 



1 See Judd, J. S., "The Efficiency of Some Protective Adaptations in securing 

 Insects from Birds," American Naturalist, Vol. 33, pages 461^84. 



Hornet mimicked by locust borer, a beetle. 



