80 THE SOLITARY WASPS. 



in his doorway, with a blade of grass. He always attacked it 

 valiantly, and sometimes grasped it so tightly in his mandibles 

 that he could be drawoi out of the nest with it. 



When the female returns to the nest with a spider the male 

 flies out to make way for her, and then as she goes in he alights 

 on her back and enters with her. When she comes out again 

 she brings him with her, but he at once re-enters, and then, 

 after a moment, comes out and backs in, so that he faces out- 

 ward as before. 



In one instance, with ruhrocinctum, where the work of stor- 

 ing the nest had been delayed by rainy weather, we saw the male 

 assisting by taking the spiders from the female as she brought 

 them and packing them into the nest, leaving her free to hunt 

 for more. This was an especially attentive little fellow, as he 

 guarded the nest almost continuously for four days, the female 

 sometimes being gone for hours at a time. On the last day he 

 even revisited the nest three or four times after it had been 

 sealed up. 



It is upon the female that the heaviest part of the work de- 

 volves. As soon as she has put the nest in order she begins the 

 arduous task of catching spiders wherewith to store it. It usu- 

 ally takes them from ten to twenty minutes to find a spider and 

 bring it home, but they are sometimes absent for a much longer 

 time. When the spider has been can*ied to the nest the process 

 of packing it in begins. This occupies some time and, appar- 

 ently, a good deal of strength, the female pushing it into place 

 with her head with a total disregard of its comfort, all the spi- 

 ders that are caught being pressed and jammed together into a 

 compact mass. While she is busied in this way she makes a loud, 

 cheerful humming noise. The number of spiders brought seems 

 to depend upon their size, in which quality they vary greatly, 

 the largest ones being six or eight times as large as the smallest. 

 Ruhrocinctum fills her nest with from seven to fourteen, wliile 

 the larger albopilosum brings as many as twenty-five or thirty. 

 Those that we examined represented many different genera, and 

 even different families, although they were usually Epeiridae. 



