WASPS, SOCIAL AND SOLITARY 



Trypoxylon live so long as the most perfectly paralyzed 

 spiders of the mud-daubers. Two of them lived ten and 

 fifteen days respectively, while with Pelopaeus one sur- 

 vived until the thirty-eighth and one until the fortieth 

 day. 



The egg requires from forty to sixty hours for its de- 

 velopment, and the larva feeds for seven or eight days 

 before spinning its cocoon. Those that we watched 

 usually disposed first of the abdomen and then of the 

 cephalothorax; sometimes they would consume several 

 abdomens before attacking the other parts. After the 

 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 general appearance and structure those 

 of Pelopaeus. 



When a female returns with 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 by other wasps ; but we do not wish to 

 cast any reflection upon the sense of locality of a crea- 

 ture that is able to find one particular straw out of the 

 many thousands in an expanse of stack twenty feet 

 high by twelve wide. We ourselves can testify, from 

 experience, to the extreme difficulty of the task. 



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