HUNTERS OF LARGE ORTHOPTERA 163 



dragged in her grasshopper, a little parasitic Dipteron ar- 

 rived and hovered about the place, like an evil spirit. It 

 poised persistently over .the hole, and tried to get in when- 

 ever the wasp's back was turned. The wasp would occa- 

 sionally whirl suddenly around, glare and jump at it de- 

 fiantly and it would dart away, only to return at once as 

 teasingly as ever. Such persistence! Such perfect adap- 

 tation ! On the spot as sure as fate and as inevitable ! 



FIG, 37. Priononyx atratum filling her burrow. Natural size. 



The wasp pounded and buzzed and labored for fourteen 

 minutes, packing dirt in the depression until the ground was 

 so hard and smooth that no trace of a hole remained. She 

 stood squarely on her head, pushing downward so hard that 

 twice she started to turn a somersault and just saved her- 

 self with difficulty; after that experience, she ingeniously 

 altered her position for pounding, with her hind legs braced 

 against the dirt and spread to their fullest extent, and one 

 middle leg (the left one) thrown clear over above her head 

 to serve as a prop and keep her from turning a somersault 

 (fig. 38). She showed much mechanical skill in spreading 

 her hind legs and bracing herself by placing one middle leg 

 forward, to hold her balance and yet get more power for her 

 work. When the closing of the hole was completed, she 

 straightened up and took one look at it, then in a flash arose 

 in the air and dashed away across the fields so swiftly the 

 eye could not follow her, and was lost in the distance. Even 



