20 
Psyche 
[March 
Fig. 8. Female Ammophila azteca at final closure of her nest. A small 
pebble is being held in the mandibles and used for packing soil in the filled 
burrow. 
nests of A. procera in Texas which did not contain eggs, Tilden 
(1953) had the same experience with this species in California, and 
Criddle (1924) observed a female of this same species in Manitoba 
place a caterpillar in a nest one day and then dig it out the next day, 
return it to the nest, and lay an egg upon it This is an aspect of 
behavior requiring much further study. 
Parasites. — Chrysidid wasps (Ceratochrysis perpulchra Cresson) 
were observed commonly in the nesting area of A. azteca at Jackson 
Hole, but I am unable to state definitely that they were parasitizing 
the Ammophila. The chrysidids would often land on the soil near 
Ammophila nests, and on several occasions they were seen to enter 
nests either partially dug or partially closed, in which case they were 
normally driven away by the Ammophila. On one occasion a chrysidid 
returned after the Ammophila had completed her closure and spent 
several minutes around the nest, but I did not see her dig into it. 
