90 
Psyche 
[March-June 
been deposited in the Museum of Comparative Zoology, Cambridge, 
Mass., and the SUNY College of Forestry, Syracuse, N. Y. 
Nesting Behavior 
Ecology. Our observations on B. distinctus were made at two 
widely-separated localities. The first site, a small mound of sand 
overgrown with sparse grasses and other plants (Fig. i), occupied 
a portion of a man-made sand pit near Colonie, Albany County, 
New York. The entrances to three nests were located in the vertical 
sides of the mound, just beneath the overhang (Fig. 2), and were 
situated so that they did not receive direct rainfall or sunlight. A 
fourth female was captured on a sand cliff several meters away 
but her nest was not discovered. The second area, in Bedford, 
Middlesex County, Massachusetts, comprised a sand-bank with a 
slope of about 45 °. One nest entrance was located in the side of 
the bank, near a projecting stone. At both sites the entrances were 
left open by the wasps during the periods of observation, although 
the burrows could have been closed farther inside. 
At Colonie we observed females provisioning nests between July 7 
and 16, 1970, whereas at Bedford one of us (HEE) noted a female 
nesting on Sept. 22, 1971. These collective dates of observation 
suggest that B. distinctus may have two generations per year in the 
Northeast, although the possibility of a single generation with stag- 
gered emergence should not be overlooked. 
Cazier and Mortenson (1965) found B. distinctus nesting in 
“bare . . . sandy soil” near Portal, Arizona. One nest was located 
inside a vertical rodent burrow, the entrance being situated 5 cm 
below ground level on the “east wall.” 
Burrow construction. B. distinctus females apparently do not 
begin their burrows from the sand surface but utilize appropriate- 
sized nests of other insects, possibly those of solitary wasps, bees, or 
tiger-beetles. These burrows are renovated and modified accordingly. 
One wasp at Colonie was observed searching for a. nest-site along the 
vertical portion of the sand mound underneath the overhang. She 
flew slowly and non-randomly, entering a variety of open burrows 
of small diameter. She would often exit several seconds after enter- 
ing and resume her searching. In flight, her behavior resembled 
that of a Mimesa or small Trypoxylon, both of which search for 
pre-existing burrows in a similar manner. After repeatedly entering 
and leaving a burrow of small diameter behind a spider web, she 
stayed inside for several minutes. She was later dug out of this 
