1971] 
Talbot — Formica dakotensis 
175 
warm. At 12:30 p.m. it was 95 0 F. down in the grasses as well 
as up in the sun. 
The one female sighted acted quite differently. She was seen 
down among the grasses at 11:45 a.m. and at 12:32 p.m. she 
appeared again walking on a bramble stem. A male lit near her, 
wings spread. He found her and they mated on the under side of 
a leaf. 
During the 70 minute flight only 15 males were observed to fly 
and only one female appeared. The sparseness of the flight may 
have been due to high temperature or there may have been only a 
few males and females mature enough. 
The next three flights (September 6, 9 and 12) were equally 
sparse with only 10, 19 and 8 males flying and only 3, 5 and 3 
females seen. Temperatures were again high and at flights end 
males again tended to drop as they fluttered and tried to take off. 
In each case weather conditions were not ideal. On September 6 
the ants disappeared entirely when a cloud dropped light from 3400 
to 2800 foot candles, and no males were in sight for 12 minutes, 
until the light began to brighten. On September 9 flight was troubled 
both by little gusts of wind and by passing clouds, which not only 
caused fluctuating light but also slight rise and fall of temperature. 
On September 12 the sky was bright and clear but a little wind 
(1/2 to 2 m.p.h.) blew almost constantly so that males could climb 
and fly only during brief quiet intervals. In all four flights very few 
alates came out trying to fly and at no time were there more than 
six males and two females in sight. 
The following three flights were quite different in that alates 
were abundant and eager to fly and many flew under conditions no 
better than those of the first flights. 
The largest flight occurred on September 19 after a week of 
bad weather had kept the ants inside. The cool and foggy morning 
(51 0 F. at 7:25 a.m.) warmed quickly and by 10:15 the sun was 
bright (6000 ft. c., 71 0 in sun and 68° in shade at nest). A few 
workers were performing the usual chores of adjusting bits of grass 
on the mounds but none was guarding an entrance. At 10:30 (82° 
in sun) workers were guarding exits out in front, but not behind 
the nest where it was still cool (68°). Two males had just escaped 
and were at the bases of grasses. By 11 a.m. (82°, 6600 ft. c.), two 
males had started to climb and a female was out on the ground. 
Just then a 5 m.p.h. gust of wind turned them all back. Immediately 
after the gust stopped several males climbed and at 1 1 :oq the first 
flew (86°, 6600 ft. c.). When the wind again moved plants and 
