WASPS, SOCIAL AND SOLITARY 



When the filling of the nest was nearly completed, 

 we caught the wasp, and after taking the spider, threw 

 back the earth into the hole. Subviolaceus, who had 

 watched the homecoming from a respectful distance, 

 now felt that her turn had come, and descending upon 

 the spot began to dig. Not finding anything, she shifted 

 her position several times, and worked industriously, 

 even returning after we had frightened her away. 

 Sharp says that a Ceropales has been observed to ovi- 

 posit on a spider, not while it was being carried in, but 

 subsequently by entering the nest for the purpose; 

 and the actions of subviolaceus pointed to similar in- 

 tentions on her part. We have watched her for an hour 

 at a time running into the open nests on the Bembex 

 field, sometimes coming out again directly and some- 

 times remaining inside for several minutes. It is not 

 likely that she would utilize the flies of Bembex, but 

 it may be that she was looking for the Pompelid nests 

 that are often made in the same locality. Scelestus did 

 not notice subviolaceus, and it is difficult to see why a 

 wasp should be disturbed by the presence of a para- 

 site. In making and storing her nest she is the blind 

 instrument of an impelling power ; she knows what she 

 must do, but not why she does it. Her descendants are 

 in most cases as completely outside of her experience 



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