138 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



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

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

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



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

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

 fly was causing me great annoyance by biting my ankles, and as a 

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

 While fighting the flies I observed a wasp searching about my shoe, 

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

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

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

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

 began to dig at a point 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 surrounding objects could 

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

 for my trampling 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 until 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. When the wasp brings food to the nest 

 she holds it with her intermediate pair of legs tightly clasped beneath 

 her and while resting upon her hind legs she digs open the nest with 

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

 accomplishing 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 while 

 opening the nest, but this is never done until by trial the wasp finds 

 she can not open the nest while retaining her burden. It is under 

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

 She is, however, just as likely to be assailed while holding it but with 

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

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

 testants grappling 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 rolling on the sand a third 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 



