1934 ] 
Biological Notes on Sphex wrightii 
155 
more was chewed loose from the sides of the opening. The 
loose soil filler was not great in quantity, and during her 
activity in securing it, small pebbles found in it were car- 
ried away and rejected. 
The last phase of tunnel filling and protection consisted 
first in a diligent search for a large pebble. That she had 
an object of large size in mind was strongly suggested by 
the fact that she appeared interested only in the big ones. 
Too, she brought pebbles three different times and at- 
tempted to use larger ones than would fit, before one was 
Fig. 1 . Ventral view of hibernating larva 
of Sphex wrightii (Cresson). The 
head of the entire larva is above. Sketch 
of side view of head and anterior segment 
to the right. X6. 
finally approved. It was a large and heavy object, but it 
fitted into the orifice and to spare, with a portion extending 
above the surface. She twisted this about in place, and 
vibrated it vigorously. 
At this time another ant, a smaller species this time, 
bothered her not a little. She soon drove it away, however, 
and continued with the loose soil or in pushing and vibrat- 
ing the pebble. A small stem unearthed in obtaining filler 
was seized in her jaws, carried away and left with the other 
rubbish of the surrounding area. 
The nest filling was quickly finished, and the wasp flew 
away in and among the branches of tumble weeds where 
