VI THE YELLOW-WINGED SPHEX 89 



more robust than her adversary, allows herself to be 

 robbed with impunity, limiting herself to a fruitless 

 pursuit, and flying like a coward when the intruder, who 

 seems not even to perceive her, turns round to come 

 out of the burrow ? Is it with insects as with men, 

 the first quality needed for success is audacity — 

 audacity — audacity ? Certainly the usurper had no 

 lack of it. I can still see that Tachytes, imper- 

 turbably calm, going and coming before the meek 

 Sphex, which stamped with impatience, but did not 

 venture to fall upon the thief. 



Let us add that in other circumstances I have 

 repeatedly found this Hymenopteron, I suppose to be 

 a parasite — this Tachytes nigra, dragging a cricket 

 by one of its antennae. Was it a prey lawfully 

 acquired ? I would fain think so, but the indecision 

 of the insect which strayed about the ruts in the 

 paths as if seeking a convenient burrow always left 

 me suspicious. I have never been present when 

 it burrowed, if indeed it ever does undertake that 

 labour, and what is more, I have seen it abandon its 

 game to decay, perhaps not knowing what to do 

 with it for want of a hole where to put it. Such 

 wastefulness seems to indicate goods ill-gotten, and 

 I ask myself if the cricket were not stolen when the 

 Sphex left it on her threshold ? I also suspect 

 Tachytes obsoleta, banded with white round the 

 abdomen like Sphex albisecta, which nourishes its 

 larvae with crickets such as are hunted by the latter. 

 I have never seen it digging galleries, but I have 

 caught it dragging crickets that the Sphex would not 

 have disdained. This similarity of food in species 

 of different genera makes me doubtful whether the 



