Psyche 
[March 
16 
4 
NEST DEPTH 
T3 A I A2 A3 A4 A5 
SEGMENT OF PREY 
Fig. 4. Number of nests of Ammophila azteca (all Jackson Hole, Wyo.) 
exhibiting various depths (in centimeters). In each case the measurement 
was rounded off to the nearest half cm in the field. Fig. 5. Number of 
examples of oviposition on various segments of the prey (all Jackson Hole, 
Wyo.). T3 — third thoracic segment; Al . . . = various abdominal seg- 
ments. 
is more than one active nest, she inspects the one containing a larger 
larva (see detailed data on no. 2030, below). However, other in- 
spections may occur later in the day (see also below). The entry and 
reclosure resemble closely the behavior occurring when the wasp is 
bringing prey. 
The maximum number of prey found in any nest at Jackson Hole 
was six (2030D), but the nest studied in Yellowstone contained 
seven (Evans, 1963). It appears that about two days are required 
for hatching of the egg, about five days for larval feeding. Apparently 
females bring in the last prey and make the final closure when the 
larva is in the last instar and at two-thirds its full size; thus final 
closure usually occurs six or seven days after the nest is dug. 
Oviposition. — The egg is laid on the first prey placed in the cell. 
It is glued firmly by the anterior end to the side of the caterpillar, in 
a more or less vertical position (Fig. 9, lower figure). As in many 
species of A?nmophila, there is much variation in the placement of the 
egg. At Jackson Hole, one egg was found on the third thoracic 
segment, others on each of the first five abdominal segments, but more 
on the second abdominal segment than elsewhere (Fig. 5). The single 
nest studied in Colorado contained a caterpillar bearing an egg on the 
fourth abdominal segment. 
Successive nests of individual females. — As mentioned earlier, it 
became apparent in the course of studies at Jackson Hole that each 
female prepares all of her nests in a small nesting arena. It also 
became apparent that each female prepares an unusual number of 
nests. For example, when I dug out the nest of no. 2013, an un- 
