92 



KLKMKXTAKY STUDIES IN INSECT LIFE 



hi<>-hest forms of insect instinct in this class. Such in- 



o 



stinctive acts have been fully discussed in the previous 

 chapter. To the same class of acts belongs the care 

 with which certain insects, such as butterflies, deposit 

 their eggs in the vicinity of the natural food plant of 

 their offspring. The most wonderful of all is that of 

 the Pronuba moth, discussed elsewhere (p. 112). The 



FIG. 71. Female wasp (Sphes speciosus) carrying a cicada to her burrow, 

 an instinctive act associated with reproduction. Natural size. (After Kiley.) 



Pronuba moth gathers the pollen and carries it to the 

 proper place in order that the yucca blossom may be 

 fertilized to furnish succulent seeds for the young which 

 is to hatch from the egg she places in the ovary of the 

 yucca flower. This is an instinct most wonderful in its 

 perfection, and certainly as obscure in its origin. 



Limitations of Instinct. Instinct has certain bounds, 

 and when activities have passed beyond these bounds 

 they become something more than instinct. A wasp 



