96 
Psyche 
[Vol. 92 
Table I. Effects of acclimation on temperature preferences of Solenopsis xvloni 
and 5. invicta collected during the winter. 
Species 
Relative Humidity 
Acclimation 
Temperature Preference 
N 
(%) 
(°C) 
(x± s.d.,°C) 
S. invicta 
0 
12 
23.8 ± 1.8 
10 
0 
22 
23.2 ± 1.3 
15 
0 
32 
21.0 ± 2.4 
10 
100 
12 
27.5 ± 1.2 
10 
100 
22 
29.7 ± 2.6 
15 
100 
32 
25.3 ± 2.8 
11 
S. xvloni 
0 
12 
24.9 ±1.1 
5 
0 
22 
25.4 ± 2.2 
10 
0 
32 
24.8 ± 3.5 
5 
100 
12 
27.2 ± 1.8 
12 
100 
22 
29.7 ± 2.4 
10 
100 
32 
26.0 ± 2.4 
7 
ences among species and between S. invicta collected during sum- 
mer and winter months were analyzed with the General Linear Re- 
gressions Models and Analysis of Variance of S. A. S. (Helwig and 
Council, 1979.) 
Results 
The control responses of each of the four species were analyzed 
separately with the Kolmogorov-Smirnov test using the null hy- 
potheses that the observed distribution should not differ from the 
predicted theoretical frequency distribution of the same number of 
responses on each of the twelve areas in the chamber. The maximum 
deviation (D) acceptable at the 0.05 confidence level under the speci- 
fied theoretical cumulative distribution is D = 0.294, N = 20. The 
results were S. aurea D = 0.218; S. geminata D = 0.120; S. invicta 
D = 0.1 17; and S. xvloni D = 0.168. Therefore, the null hypothesis 
was accepted for each of the four species: During the control tests 
the ants exhibited no preference for any part of the experimental 
chamber. 
Analysis of variance indicated that species identity [F(3,269) = 
7.2], relative humidity [F( 1 ,269) = 1 83.7], and acclimation [F(2,269) 
= 10.2] were all highly significant (p < 0.001) during experimental 
trials. None of the two way interactions were significant (p > 0.05), 
but the three way interaction (R. H. X acclimation X species) was 
[F(6,269) = 2.7, 0.05 > p > 0.01]. 
