206 WASP STUDIES AFIELD 



those of Pompilus. They consist of two layers, the outer 

 very thin and the inner, parchment-like. The larvae hiber- 

 nate and turn to pupae in the spring, appearing in summer 

 and autumn. 



A similar type of behavior has been reported by David- 

 son for a sister species, under the name of Sphex elegans: 

 "For nesting sites they prefer the larger stems, first gnaw- 

 ing through the thin partitions opposite the leaf insertions 

 which naturally divide an otherwise hollow stem. The 

 parent wasp first packs the bottom of this tube with very 

 fine grass-like fibers, which on investigation prove to be 

 fine strips of the loosely fibrous bark of Audibertia poly- 

 stacha, from one-fourth inch to one and one-fourth inches 

 in length. On this is laid the larval food supply, which 

 consists, on an average, of from seven to eight tree crickets. 

 The egg is laid on the breast of one of the crickets, a wad 

 of bark fiber is placed on the top which forms the base of 

 the next cell, etc. A copious wad, sometimes three or 

 four inches in depth, protects the topmost cell." 



The prey of Ammobia bridwelli Fernald. [S. A. Rohwer]. 



Late one August afternoon, at Meramec Highlands, Mis- 

 souri, this wasp was seen entering her burrow in the soft, 

 loose earth, under an open shed. Since it was impossible 

 for us to remain there,, we captured the wasp and dug up 

 the nest. It was well provisioned with the long-antennaed 

 Orthoptera, Camptonotus carolinensis Gerst. [A. N. Cau- 

 dell]. They were eight in number, three males and five 

 females. The earth was so loose that we could get no idea 

 of the shape of the burrow. 



