A Parasite of the Bembex 



stinacy has worn down the mother's prudence. 

 In that second when her vigilance is relaxed, 

 the Flies are straightway there. One of 

 them, occupying the most favourable spot, 

 swoops upon the disappearing prey and the 

 deed is done : the egg is laid. 



There is ample evidence that the Bembex 

 is aware of the danger. The Wasp knows 

 how disastrous the presence of the hateful 

 Gnat may be to the future of the nest; on 

 this point her prolonged attempts to put off 

 the Tachinae, her hesitations, her flights leave 

 not the shadow of a doubt. Then how is it, 

 I ask myself once more, that the Fly-huntress 

 allows herself to be worried by another of 

 the tribe, by an infinitesimal bandit, incapable 

 of the least resistance, whom she could reach 

 with a sudden rush if she tried? Why not 

 relieve herself of the prey that clogs her 

 movements and swoop down upon those evil- 

 doers? What would be needed to extermi- 

 nate the ill-omened brood that hangs around 

 the burrow? A battue that would take her 

 a few seconds. But the harmony of the uni- 

 verse, the laws that regulate the preserva- 

 tion of species will not have it so; and the 

 Bembex will always allow themselves to be 

 harassed without ever learning from the 

 321 



