166 THE SOLITARY WASPS. 



tional holiday, we found fastened to it, and hidden in its folds, 

 three dainty little mud nests, eight millimeters long by five 

 wide. Each nest contained a wasp larva and a dead spider. 

 The nests were probably made one day apart since the larvae 

 spun their cocoons oa the seventh, eighth, and ninth of July, 

 giving a shorter larval stage than we have ever known except- 

 ing in the case of the little grasshopper wasp, Tachytes sp. ? On 

 July twenty-ninth a male of A. architect a issued from one of 

 the nests, and before August second two females had appeared 

 from the others. 



On the seventeenth of July we found two nests of architecta 

 fastened to the inside wall of the boat house. The larvae had 

 already pupated and by the twenty-eighth of the month the 

 wasps had flown away. From its rapid development it seems 

 probable that this species has two generations in one season. 



