296 The Hunting PVasps 



second when her vigilance is relaxed, the Flies 

 are straightway there. One of them, occupying 

 the most favourable spot, swoops upon the dis- 

 appearing 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 infinitesi- 

 mal 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 

 exterminate the ill-omened brood that hangs 

 around the burrow ? A hattue that would take 

 her a few seconds. But the harmony of the uni- 

 verse, the laws that regulate the preservation 

 of species, will not have it so ; and the Bembex 

 will always allow themselves to be harassed 

 without ever learning from the famous ' struggle 

 for life ' the radical method of extermination. I 

 have seen them sometimes, when too close- 

 pressed by the Midges, drop their prey and fly 



