H4 WASP STUDIES AFIELD 



promptly pushed up enough soil from the tunnel to close the 

 burrow. This was not roughly kicked out, but probably 

 pushed up with her head, since it seeemed to be forced out in 

 cylindrical form like a plug. At 2 130 we again visited the 

 spot and found the hole closed; but probably only tempor- 

 arily, for a probe could easily be inserted. The wasp re- 

 turned and entered, in precisely the same manner as before, 

 and immediately closed her door again from within. She 

 was not a moment too soon, for a red-bellied parasite was 

 already digging in the loose sand at her heels. 



Three days later we came back at twilight and then found 

 it apparently firmly closed, so we opened it. Only the upper 

 few inches were packed with soil; below this, the gallery 

 remained open. It ran into the tiny bank, with only a very 

 slight downward slope, for four inches, after which it 

 dropped at a steeper incline, about forty-five degrees, for 

 eleven inches, and then terminated in a chamber an inch 

 long which turned sharply to the right. The larva in the 

 chamber was already about half-grown; it was surrounded 

 by some debris, heads and legs, but in the growing dark- 

 ness we could not determine what the food of the larva had 

 been. 



Thus they frequently, if not usually, choose for their 

 nesting-site some little slope or the side of a depression 

 where they can dig into the side-wall, and where. the dirt 

 cast out can roll down the slope and be out of the way. A 

 number of burrows were found going directly horizontally 

 into clay banks. 



We chanced to see a sleepy P. punctatus just getting up 

 one June morning at 7 : 20. She slowly and carefully 

 opened the entrance to the hole from within, not by pushing 

 the dirt out as she does on other occasions, but by very care- 

 fully and slowly working it back into the burrow, probably 

 by scraping it under her. First a little opening no larger 



