1971] 
Talbot — Formica dakot crisis 
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small grass shelters around such plants as strawberry ( Fragaria 
virginiana Duchesne), yarrow (Achillea millefolium L.) and golden 
Alexanders (Zizia aurea L.), all of which had aphids at the union 
of stem and root. 
W orker activity. Workers seemed more stereotyped in their 
behavior than did many Formica. They moved in files in their 
tunnels or when going up a tree trunk. At the nest some carried 
grass to replace thatch, some carried out empty pupa cases and occa- 
sionally one carried a pupa into the open. Ants could come out of 
the nest just before sunrise at temperatures as low as 50° to 53 0 F. 
and they avoided temperatures in the high 8o’s. 
If the nest was disturbed they ran up onto hands quickly and bit 
hard, hanging on so tenaciously that they had to be picked off one 
at a time. They gave off a strong odor when thus disturbed. 
Development of brood. Numerous small clusters of eggs were 
present on June 3 and more were in the nest on June 7 and 11. 
The first larvae were seen on June 12 and the first newly formed 
worker pupae on June 16. Pupae soon became very numerous and 
were scattered in piles through all of the central mounds. By 
August 2 the first alate pupae were present. At this time pupae were 
very abundant and larvae were declining in number until after 
September 5 no more larvae were found. 
Callow workers began appearing by July 6 but worker pupae 
remained abundant through August and much of September and a 
few were still in the nest on October 1. Adult alates were found 
on August 24, 1969 and on August 27, 1970. By September 1 most 
alates were adult but as late as September 15 a few were still in 
the pupal stage. In 1970 flights began on September 5 and, after 
7 flights, there were still both males and females in the colony on 
October 1, when observations ceased. It is presumed that October 
provided a few days warm enough for the rest to fly. 
Care of brood. The moving of pupae went on constantly and 
was easy to watch by making tears in the thatch. At the height of 
the season they could be found in most mounds but by mid -Septem- 
ber, as their numbers dwindled, they were gradually consolidated 
into the central mounds, leaving the outlying ones empty. There 
was a daily task of bringing pupae up into the mounds when the 
air temperature rose above that of the ground and of taking them 
back underground in the late afternoon as the air temperature fell. 
Thatch in the mounds remained dry even when the outer surface 
and the soil beneath were drenched, and it was here that the pupae 
were concentrated during wet weather. To give ventilation and 
