138 riiOCEEDINGS OF THE NATIONAL 2fUSEUM. vol. 52. 



though I dashed buckets of water over the surface, placed a smaD 

 pile of sand over the entrance, or changed the surroundings by placing 

 paper, leaves, and rubbish about the entrance to the nest. 



Tlie following is an extreme case: I had been sitting on the sand for 

 almost an hoiu* observing a number of wasps on a day when the stable- 

 fly was causing me gi-eat annoyance by biting my ankles, and as a 

 result the sand about my feet had been trampled and disturbed. 

 Wliile fighting the flies I observed a wasp searcliing about my shoe, 

 which at the time rested flat upon the sand. She flew round and 

 round my foot, lighting first at one pomt and then at another, evi- 

 dently trying to find a means of gettmg beneath it. I moved my 

 foot aside and the wasp after searcMng the area covered by my shoe 

 began to dig at a pomt that had been directly beneath it. She digged 

 down directly into her burrow. Presently she came out, closed the 

 burrow and set forth in search of food. Here it does not seem possible 

 that the sense of sight or the relation of surromiding objects could 

 have been of any possible use in locating the entrance to the burrow, 

 for my trampHng had changed everything within 2 feet of the nest, 

 and my foot was directly over the entrance at the time she began her 

 search for her nest. 



As stated above, no food is placed in the brood chamber imtil the 

 egg is hatched, and even then sufficient is not provided at one time 

 for the development of the larva. It is thus necessary for the wasp 

 to open and provision the nest on two or more days. My investiga- 

 tions clearly established the fact that the nest is provisioned at least 

 twice and possibly oftener. Wlien the wasp brings food to the nest 

 she holds it with her intennediate paii* of legs tightly clasped beneath 

 her and while resting upon her liind legs she digs open the nest ^\^.th 

 her front pair. This is neither the easiest nor the quickest way of 

 accomphsliing the work of opening the nest, but it is much the safest. 

 If she releases her hold upon her booty it is almost sure to be carried 

 off by another wasp in search of food for her young. Sometimes the 

 dead insect is so large that the wasp is compelled to lay it aside wliile 

 opening the nest, but tliis is never done imtil by trial the wasp finds 

 she can not open the nest while retaining her biu-den. It is under 

 such conditions that she is most hkely to be robbed of her property. 

 She is, however, just as Hkely to be assailed while holding it but %\'ith 

 less danger of losing it. Tlie struggles at the mouth of the burrow 

 for the possession of a dead insect are frequent and furious, the con- 

 testants grapphng and rolling over and over on the sand. Frequently 

 it happens that the prey is dropped in the struggle and while the pair 

 of contestants are roUing on the sand a thii-d wasp comes along and 

 settles the quarrel by quietly carrying off the coveted treasure. This 

 fighting over food is not limited to struggles for possession at the 

 entrance to a nest, but may occur at any time when two wasps may 

 chance upon a dead insect on the sand at the same time, or when one 



