The Fly-hunt 281 



attacks, explain why the Bembex serve up dead 

 prey to their larvae and consequently cater for 

 them from day to day. 



Let us watch the Wasp as she returns to the 

 burrow with her capture held under her abdo- 

 men between her legs. Here comes one, the 

 Tarsal Bembex {B. tarsata), who arrives laden 

 with a Bee-fly. The nest is situated at the 

 sandy foot of a steep bank. The huntress 

 announces her approach by a shrill humming, 

 which has something plaintive about it and 

 which continues until the insect sets foot to 

 earth. We see the Bembex hover above the 

 bank and then dip straight down, very slowly 

 and cautiously, all the time emitting her shrill 

 hum. Should her keen eye descry anything 

 unusual, she slackens her descent, hovers for a 

 second or two, goes up again, comes down again 

 and flies away, swift as an arrow. After a few 

 moments, here she is once more. Hovering at 

 a certain height, she appears to be inspecting 

 the locality, as if from the top of an observatory. 

 The vertical descent is resumed with the most 

 cautious slowness ; finally, the Wasp alights 

 with no hesitation whatever at a spot which 

 to my eye has naught to distinguish it from 

 the rest of the sandy surface. At that instant 

 the plaintive whimper ceases. 



The insect, no doubt, has landed more or 



