Field Studies of the Non-Socral Wasps 335 
few times, alighted again in the normal manner and 
plunged in. 
While another nest was being observed, a troublesome 
weed that grew near it was pulled up; this changed the 
topography of this tiny area. Upon returning several 
hours later we found four weevils lying out on top of the 
ground, and the returning wasp even then circled and 
buzzed about the hole for fully half an hour before she 
would enter. It was evident that she had discarded the 
weevils lying there in the sun; either she had dropped 
them as she had come back from foraging and had lost 
them in her confusion at finding the familiar landmarks 
altered, or she had suspected that, since the region had 
been changed, her nest had probably been meddled with 
and so, like other wasps of our acquaintance, she had 
thrown out the stores she already had as though they 
were contaminated. 
One nest was especially conspicuous because at that 
point in the road the surface of the ground was covered 
with black cinders, while the circular mound of subsoil 
around the hole was gray. This contrast made the nest 
itself a conspicuous landmark for the returning wasp. 
I watched until the wasp left home; then with the point 
of the trowel IT carefully removed this gray earth and 
replaced it with a mound of black cinders, just like the 
surrounding medium. I was quite proud of my new ac- 
complishment of building wasps’ nests, for the imitation 
was, to my eye, very accurate except for the color of 
the material. It was, of necessity, a hasty job, for the 
rightful proprietor returned from her trip in only two 
minutes. She flew direct to the location of her hole as 
usual, but just above it she brought herself up with a 
Jerk and flew to and fro over it in an agitated manner 
for several minutes. Her confusion was evident; twice 
