The Halicti : Parthenogenesis 



eral rule, for most of the backward pupae give 

 me only females. 



Once the two sexes had appeared, I ex- 

 pected a third generation that would spend the 

 w^inter in the larval state and recommence in 

 May the annual cycle which I have just de- 

 scribed. My anticipation proved to be at 

 fault. Throughout September, when the sun 

 beats upon the burrows, I see the males flit- 

 ting in great numbers from one shaft to the 

 other. Sometimes a female appears, return- 

 ing from the fields, but with no pollen on her 

 legs. She seeks her gallery, finds It, dives 

 down and disappears. 



The males, as though Indifferent to her 

 arrival, offer her no welcome, do not harass 

 her with their amorous pursuits; they con- 

 tinue to visit the doors of the burrows with 

 a winding and oscillating flight. For two 

 months, I follow their evolutions. If they set 

 foot on earth, it is to descend forthwith into 

 some gallery that suits them. 



It is not uncommon to see several of them 

 on the threshold of the same burrow. Then 

 each awaits his turn to enter; they are as 

 peaceable In their relations as the females who 

 are joint owners of a burrow. At other times, 



439 



