1934 ] 
Biological Notes on Sphex ivrightii 
151 
soil on foot to a definite place some three inches away. This 
spot continued to be used for soil deposition until the end 
of the digging. The wasp backed out of the shaft with soil, 
turned and walked with it in her jaws and fore legs to this 
spot, released the load, walked back and down the tunnel 
for more. 
This process and sequence continued 91 times between 
1:37 and 1:58 P. M., during which time the wasp was not 
at all distracted from her work. Then, either feeling a need 
for a brief rest or change of activity, or more probably a 
solicitude for the safety and welfare of her already cap- 
tured and suspended prey, she spent some time walking 
among the branches of one of the several tumble weeds 
which surrounded her nest and in visiting the moth larva. 
But the delay lasted only one minute, after which she was 
back again and digging. The period of excavation ended 
at 2:03 and the total number of observed loads removed up 
to this time was 109. Since she was well started when I ar- 
rived, the grand total doubtless was more, but probably not 
in excess of 125, or 130 at the most. 
This small wasp spent from 2:03 to 2:06 in finding her 
hidden prey and in bringing it to the nest. She walked over 
and among the thistle stems, seemingly meeting with some 
difficulty in locating the larva. This is not surprising, for 
the branches in this area were exceedingly thick. Reaching 
the larva resting in the fork of a stem, she grasped it with 
her jaws on the ventral side back of the true legs, wrapped 
her fore legs about it and started. It was a green geomet- 
rid, long and slender, but larger and heavier than the wasp 
and bulky in comparison. 
The trip to the tunnel was over stems, through and among 
branches, and the wasp met with minor difficulties on the 
way. She had to change her hold on the prey a number of 
times, and on five occasions was forced to turn back and 
bite or pinch with her jaws the posterior end of the abdo- 
men of the prey. This was due to the fact that it was able 
to hold onto a stem with its anal legs and with sufficient 
force, when in a tight place, to momentarily stop the prog- 
ress of the wasp. Once, after she had been thus hindered, 
