HUNTERS OF LARGE ORTHOPTERA 173 



tion have always contained one of three species of 'grass- 

 hoppers : Dissosteira Carolina Linn, nymphs, Arphia 

 corinata Scud. ? large nymphs, or Melanoplus femur- 

 rubrum DeG. 4 



The first named was the most abundant. Riley, Packard 

 and Thomas 5 record them as pursuing and capturing the 

 nymphs of the Rocky Mountain locust, Coloptenus spretus, 

 and Adams (loc. cit. p. 195) also says they use Melanoplus 

 femur-rubrum. The prey was always placed in the oval 

 terminal chamber, with its head toward the wall, away from 

 the exit a wise precaution which would prevent the hop- 

 per's escape in case the stinging should be imperfectly done. 

 The upper portion of the channel was always filled with 

 earth, and near the surface this was packed so firmly as to 

 be indistinguishable from the surrounding soil. The hori- 

 zontal chamber at the end was not filled with earth, but con- 

 tained only the grasshopper surrounded by plenty of air 

 space. May it be that this terminal chamber is made in this 

 form so that the dirt will not roll in and pack around the 

 grasshopper ? 



The faithfulness of these wasps in returning to the un- 

 finished nests is variable. We have described above the case 

 of one wasp which spent a whole hour in diligent search for 

 an unfinished hole, only to fill it up and desert it the moment 

 she found it. On one other occasion, we disturbed a wasp as 

 she was making her nest, and found the next day that she 

 had returned and finished it. In another instance we met 

 exactly the opposite behavior: the wasp with her prey, a 

 large Dissosteira Carolina, right beside her, was putting the 

 finishing touches to her burrow when our footsteps fright- 

 ened her away. She returned and found the hole again be- 

 fore we passed on, but when we came back that afternoon 



* All kindly identified by Mr. A, N. Caudell. 

 5 U. S. Ent ; Cpmm. 1877: 318, 



