Field Studies of the Non-Social Wasps 333 
line,’’ but she literally makes a round trip. Several which 
I watched going to the cornfield on the other side of the 
railroad track, left the nest flying northward; after fifty 
feet or so they circled around toward the east, and after 
an absence of from 3 to 8 minutes they came back with 
their prey, by way of the south. Just how general this 
habit of circular flight is I do not know. 
They work with surprising rapidity in bringing in their 
victims. I timed a number of them on different occasions 
and they usually took only 3 to 8 minutes to capture a 
beetle and return. They lost no time in finding the open 
nest, plunged in, and stored the booty speedily. 
It was noticed that practically all of the weevils 
brought in by these Cerceris were covered with a crust of 
earth. That raises the question: do these beetles oceupy 
subterranean habitations where these wasps are obliged 
to dig for them? The wasps seem to find them so easily 
and in such large numbers that there must be an abun- 
dant supply of them near, perhaps in the cornfield. To 
ascertain the hunting habits of these wasps one ought 
to know something of the two species of beetles that they 
hunt, Livus concavus, properly known as the rhubarb 
cureulio, and Thecesternus humeralis. Of the latter spe- 
cies, Mr. E, A. Schwarz writes: ‘‘The life history of 
this weevil still remains unknown, but the imago is quite 
common under dried cow dung in our prairie states, or 
under stones in dry situations in Indiana, western Mis- 
souri, Nebraska, Colorado, New Mexico and Texas. Most 
of the specimens in our collection are covered with a 
thick crust of dirt, which shows that the earlier stages 
are passed underground and that the larvae will be found 
In the roots of some plants. Oceasionally specimens of 
the imago have been found above ground on the stems 
of various plants. * * * A somewhat allied species, 
