Psyche 
[March 
ADULT BEHAVIOR 
Provisioning. — The earliest any wasps flew from the nest in 
the morning was just before 0800 hours, the times of first departures 
on three consecutive days being 0806, 0751 and 0824. Altogether 
15 trips for prey were timed; these required from 8 to 140 minutes, 
the mean being nearly 37 minutes. At this rate, it would require 
a single female about three days to collect the 46 Collembola needed 
to provision the average cell. In one nest observed continuously, the 
two females made a total of 13 trips for prey over a period of 7 
hours 28 minutes. 
Table 1. Summary of contents of 22 active Microstigmus comes nests, 
collected at night and preserved immediately. 
Number 
of Adults: 
Female Male 
Immatures : 
Pupae Prepupae Larvae Eggs 
Incom- 
plete 
Food 
Masses 
Para- 
sites 
Empty 
Total 
56 19 
28 5 14 17 
11 
5 1 
2 
81 
’Parasite egg on mature M. comes larva in one case. 
When the females returned to the nest they invariably alighted 
on the side of the nest, then quickly crawled up and inside. This 
behavior made it possible to determine whether prey was being car- 
ried, and to ascertain that it was held in the mandibles. Generally 
the female spent less than a minute at the nest between prey hunting 
trips. Usually she was in and out again quickly, having spent less 
than 5 seconds inside. This was followed by walking slowly over 
the outside of the nest for up to 60 seconds before departure, usually 
visibly grooming the mouthparts during much of this time. The ob- 
served wasps never departed directly from the nest entrance. Often 
the females made brief “orientation” flights before disappearing; 
these consisted of two or three circular flights about 5 cm beneath 
the nest. 
Nest Maintenance and Defense . — All nests observed were found 
to have at least one adult present at all times, and wasps were active 
on the outside of the nest throughout the day. This extra-nest 
activity was classified as “inspection” trips or “maintenance” trips. 
Usually, “inspection” trips were brief, with the wasp crawling 
once around the nest quickly from top to bottom or in a spiral 
pattern and then reentering the nest. These trips were made at 
irregular intervals throughout the day and seldom did five minutes 
elapse without a wasp crawling on the nest surface at least once. 
In one representative hour, 29 “inspection” trips were made, re- 
