146 
Psyche 
[September 
70 to 90° with the horizontal. In the one nest successfully excavated 
at Granby Center, the burrow was 48 cm long and reached a point 
37 cm in vertical depth (Fig. 2). Two nests at Lexington both had 
burrows only 24 cm long, reaching depths of from 17 to 19 cm 
(Fig. 4). The initial burrow terminates blindly, and it is apparently 
only after several bees have been taken and stored in the burrow that 
the first cell is constructed. 
I obtained no precise data on the duration of nests or the final 
number of cells per nest. Females evidently remain with a single 
nest for several days (at least three), but they prepare several nests 
in the course of the nesting season. I found no more than two cells 
in any of the nests excavated, but it seems very probable that the 
final number of cells in any one nest averages higher than this. The 
cells were found to be located at or slightly below the terminus of 
the burrow, at a vertical depth of 33-35 cm (Granby Center) or 
24-26 cm (Lexington). The cells are small, about 10 mm long by 
8 mm high; in the nests excavated the two cells were separated by 
only about 2 cm of soil. 
As usual in philanthine wasps, the bees are stored in the burrow 
for a period before being introduced into a cell. In some cases they 
are stored about halfway down the burrow (9 to 17 cm deep), in 
some cases at the bottom of the burrow. One nest: at Lexington had 
seven bees halfway down and one at the bottom. The stored bees 
are surrounded by a small amount of loose sand. 
Provisioning the nest. — Bees are paralyzed at the site of capture 
and are carried to the nest beneath the body of the wasp, the middle 
legs providing the major grasp as usual in this genus. The wasps 
fly in to their nests low, only 10-15 cm above the ground. The nest 
entrance is opened by a few scrapes of the front legs and the bee 
carried directly in. Females watched over a period of time appeared 
to provision very slowly, bringing in bees at the rate of about one 
every half hour. Usually females remain within the nest for only 
20-30 seconds, but occasionally they remain within for long periods 
of time, presumably digging a cell and introducing the bees into the 
cell. From 9 to 1 1 bees are provided per cell. The egg is laid longi- 
tudinally on the venter of one of the topmost bees in the usual 
manner of members of this genus (Evans and Lin, 1959, Fig. 9). 
In both areas of study, P. lepidus preyed upon a considerable 
variety of small bees, all but one of the 69 specimens taken belonging 
to the family Halictidae. Individual nests always contained a mixture 
of species (from 3 to 7). Male and female bees were used in roughly 
equal numbers. Many of these same species of bees appear on the 
