132 FIELD ZOOLOGY. 



adult form; nevertheless these caterpillars, sluggish as 

 they are, are not without means of defense. For any- 

 living organism, the natural thing is to continue to live; 

 hence, we find that all activities of existing life forms 

 have the general trend toward the preservation of the 

 individual; though all may not be successful in every 

 case. We must remember that the struggle for existence 

 is not between the species and the conditions that surround 

 it, but between the individual and those conditions, as it 

 faces alone the manifold influences which may mean 

 persistence through adaptive response, or may present 

 the fatal alternative of death through the possibility of 

 non-adjustment to conditions. The hairy caterpillars 

 are an uncomfortable mouthful for most birds; though it 

 often happens that a specially meaty caterpillar is whipped 

 clean of the objectionable hairs by some diligent bird 

 who is likewise struggling for existence — dinner in this 

 case. The brilliantly-colored caterpillars are generally 

 let alone by birds, and it is known for some of them at 

 least, that the brilliant coloration is accompanied by some 

 poisonous substance or acrid taste, and hence they are 

 not good eating. Many of the larvas have the same body 

 colors as the things they feed on, and so pass unnoticed 

 in many cases. 



The larvEe are provided with biting mouth parts, and 

 all are fruit- or leaf-eaters; this places the members of 

 this order among the non-beneficial insects so far as their 

 larvas are concerned, but it is only in the larval stage 

 that they are troublesome. In the pupal stage the insect 

 eats little or nothing, only such food as the greedy larva 

 has provided for it; while in the adult stage, the general 

 usefulness of the moths and the butterflies to the farmer 

 and the fruit-grower can hardly be overestimated. 



