OF WASHINGTON, VOLUME XVII, 1915 75 



the fly firmly impaled upon her sting. I found it a difficult 

 matter to pull the fly away from the wasp. After having done 

 so I placed the fly still held with the forceps quite near the wasp 

 yet keeping it under the lens and saw her pounce upon it and 

 drive her sting deep into the ventral side of the thorax. Whether 

 she kills her victim by stinging it I cannot say but of her ability 

 to do so there can be no question. When she had fastened her 

 sting into the thorax of the fly she would strive to pull the fly 

 away and she used all six legs to do this. The accompanying 

 photograph (fig. 9) shows the wasp ready to open her nest, holding 

 her prey with her sting, her first pair of legs ready to dig and her 

 second and third pairs resting upon the ground. 



III. SPHEX URNARIA (DAHLB.) 



On August 1 a wasp (No. 63) of this species was observed carry- 

 ing a caterpillar to her nest. She carried it ventral side up 

 holding it with her mandibles and supporting it with the first 

 pair of legs while walking with the second and third pairs, vary- 

 ing her proceedure by making occasional flights of a foot or 

 more. When discovered she was more than one hundred feet 

 from her nest yet she went forward to it on nearly a direct line 

 although she had to pass at times through weeds almost as high 

 as a man's head. When she arrived in the immediate vicinity 

 of the nest she had to search about for some time to find it, due 

 possibly to the fact that she was somewhat confused by my 

 presence for I had to follow her very closely to avoid losing her 

 in the weeds. 



When she found the nest she laid the caterpillar aside and 

 opened the nest by digging away the sand with her front feet 

 and removing with her mandibles the pebbles and bits of wood 

 and coal with which the opening had been filled. After inspect- 

 ing the interior of the nest the wasp came out and seizing the 

 caterpillar backed down into the nest dragging it after her. 

 When she emerged she again filled up the entrance by placing 

 therein the bit of wood and coal and pebbles she had removed 

 in opening it and then digged sand in upon them. When she 

 had completed her task I captured her with my net. 



The nest contained four "measuring worms," larvae of geo- 

 metrid moths, and a larger caterpillar, the one I had seen her 

 take inside. Upon one of the geometrids was an unhatched egg 

 placed horizontally (fig. 8). Whether this is the usual mode of 

 placing the egg or whether the small size of the caterpillar made 

 it necessary to place the egg thus in this particular case I am 

 unable to say. From the position of the caterpillars in the broad 

 chamber I judge that the one bearing the egg was the first placed 

 in the nest. 



