1 86 WASP STUDIES AFIELD 



worked her way into the nest at the right side of the hopper, 

 remained in for about five minutes and emerged at the left 

 side, showing that at least she could turn around inside the 

 chamber. She went in again and this time we removed a 

 little of the soil, yet could not see fully what she was doing; 

 but this much was clear that she was standing on the hop- 

 per with her head near the fore part of the insect, quietly 

 sitting there with the abdomen pulsating for over five min- 

 utes. She came out and kicked in all of the loose dirt, then 

 dug up more with her mandibles, kicked it under her body 

 into place, and picked up and placed a few more bits until the 

 hole was once more nicely covered. She then went a few 

 feet away and calmly sat down to rest, when she was taken 

 to secure her identity. 



We dug up the nest and found a hole of the type usually 

 made by both P. atratum and thomae, only the chamber was 

 unusually long in this case. The hopper lay there with its 

 head to the wall. The egg of thomae was in its usual posi- 

 tion on the right femur, at the base of the abdomen, but lo ! 

 it was only an empty sac ! Evidently Stizus had mutilated 

 the egg by malaxation, or had sucked the contents for food. 

 We found no Stizus egg; but it is probable that, in the diffi- 

 culty of opening the nest in a harsh cinder bed, it was 

 knocked off by crumbling walls. We know that Stisus did 

 not deposit an egg during her second stay in the chamber, 

 for we could see her abdomen all the while, but we suspect 

 that she was then mutilating the egg of thomae, after prob- 

 ably having laid her own. 



We wonder by what sense ftisus found the nest. To be 

 sure, she had returned to the spot while P. thomae was at 

 work sufficiently often to get the landmarks of the vicinity; 

 but considering the remarkable way in which the nests are 

 covered and concealed we wonder how she could find the 



