84 THE SOLITARY WASPS. 



consume several abdomens before attacking tbe other parts. 

 After tbe body was devoured the legs were picked up and eaten. 

 When the supply of food, was generous, portions of the spiders 

 were sometimes left untouched. The cocoons resembled in gen- 

 eral appearance and structure those of Pelopaeus. 



"When a female returns -^dth her load she usually hunts about 

 for a few moments before finding her nest, sometimes entering, 

 first, two or three that are empty or are occupied bv other wasps, 

 but we do not wish to cast any reflection upon the sense of lo- 

 cality of a creature that is able to find one particular straw out 

 of the many thousand? in an expanse of stack twenty feet high 

 by twelve wide. We ourselves can testify, from experience, to 

 the extreme difficulty of the task. 



After the storing process is completed the female seals up the 

 nest with mud. In the case of one ruhrocinetum that we were 

 watching she began to close the opening at four in the afternoon 

 and finished her work just thirty minutes later. In this time 

 she made ten journeys for mud, bringing it in pellets in her 

 mandibles. In another case, also a ruhrocinctum, the female, 

 after bringing so many spiders that the cell was full up to the 

 very door (which we saw in no other case), went away without 

 closing it and never returned. The male seemed uneasy at her 

 conduct and several times flew away, staying an hour or two 

 and then returning; but after a time he too deserted the nest. 

 Whether some evil fate overtook the female or whether there 

 was some failure of instinct on her part can only be conjectured, 

 but the latter hypothesis is not untenable, fince out of seventy- 

 six nests that we had under observation seven were cleaned out 

 and prepared and were then sealed up empty. We have often 

 found similar oases among the nests of the blue mud-dauber 

 wasps, where it is not a very uncommon thing for the absent- 

 minded females to build their pretty little cylindrical nests with 

 infinite care and patience and then to seal them up without put- 

 ting anything inside. * 



Cocoons of ruhrocinctum that were gathered in the month of 

 August remained over the winter and hatched in May and June. 



