LUTHER BURBANK 



common enough in nature. But so extreme a case 

 as that of the yucca and the insect that is its 

 inseparable associate is seldom duplicated. 



The insect in question is a little yellowish 

 white moth, so unfamiliar that it probably has no 

 colloquial name, but known to the entomologist as 

 the Pronuba yuccasella. If you were to watch 

 closely you might see these moths visiting the 

 flowers of the yucca in the twilight. You would 

 require exceptional opportunities for observation, 

 if you were to discover precisely what takes place 

 during this visit. But entomologists have kept 

 watch to good purpose, and the terms of the 

 extraordinary coalition between the yucca and 

 the pronuba moth are now an open secret. 



It appears that the female moth that visits the 

 yucca blossoms has developed a long ovipositor 

 with which she can pierce the tissues of the ovary 

 of the plant and so lay her eggs within it. Her 

 prime object in visiting the yucca flower is thus 

 to deposit her eggs. In due course the eggs hatch 

 and the growing seeds of the yucca will furnish 

 them a supply of food. So there is nothing very 

 remarkable about this part of the procedure. 



The surprise comes when we learn of certain 

 maneuvers preliminary to the deposit of the eggs. 

 If you could watch the little moth on her visit to 

 the first flower, you would see her begin at once 



[198] 



