1967] 
Talbot — Polyergus 
307 
loiter for a few seconds and then retreat. June 13 through June 17 
were cool enough so that raiding would not have taken place in any 
season. On June 18 the Polyergus showed their first preliminary 
activity. They kept coming to the surface, one to 5 at a time. Some 
retreated quickly, while others moved away from the entrance to 
circle about on the bare nest area. At least 3 ants moved away into 
the grasses, exploring back and forth. This was interpreted as the 
first tentative scouting of the season. Next day, June 19, the first 
raid occurred. On that day workers began coming out of the nest 
at 3 155 PM, when the first flickering shade reduced the temperature 
from 90°F to 84°F. As a few circled about, some went off individ- 
ually in different directions, moving rapidly out into the grass. At 
4:45 PM an ant came in from the northwest and went directly into 
the nest entrance. Within 2 or 3 seconds Polyergus workers began 
pouring out, covering the nest area with a moving crowd which, 5 
minutes later, began traveling off to the northwest on the initial 
raid of the year. 
The raiding season probably started late in 1965, since June had 
been cold. The earliest raid ever seen was on June 1 1, 1959. Raiding 
seems to begin at the time when F. p. nitidiventris are accumulating 
their first pupae. A few newly formed pupae have been collected as 
early as June 5, in 1963 but were not found in 1965 until June 14. 
Polyergus lucidus matures its brood more slowly. A. colony dug 
into on June 15, 1965, had larvae but no pupae; and the earliest 
record of pupae was June 22, 1964. It would seem that raiding 
begins when F. p. nitidiventris pupae are just becoming available and 
while most Polyergus larvae are still small to medium size. Once 
raids have begun, they continue on almost very afternoon that the 
weather permits. The urge to raid seems especially strong during the 
early part of the season, reaching a peak in early July when there 
are the most double raids, when ants travel the greatest distance to 
outlying nests, when more brood is brought in, and when more Polyer- 
gus workers participate in the raids. By mid-August there is a 
dwindling of the number of ants which go on a raid. By this time 
perhaps all of the F. p. nitidiventris in the neighborhood have been 
raided once, twice, or more times; and the number of available pupae 
and larvae is dwindling. By early September the raiding season is 
about over. F. p. nitidiventris do not overwinter as larvae, and by 
the last of August no more are present. Pupae have been found in 
their colonies as late as September 19, but only a few were left at 
this time; and in colonies raided by Polyergus they had probably all 
