100 
Psyche 
[Vol. 92 
Summary 
The temperature preferences of brood-tending fire ants were 
determined with a linear temperature gradient. The following four 
species of fire ants were used: Solenopsis aurea , the desert fire ant; 
S. geminata , the tropical fire ant; S. invicta , the red imported fire 
ant; and S. xv/oni , the southern fire ant. The responses of ants 
acclimated at 12°, 22°, and 32° C were determined at both 0% and 
100% relative humidity. The four species differed slightly in their 
temperature preferences at 100% R. H. (26.2, 27.9, 28.3, and 29.7°C, 
respectively). Temperature preferences were reduced by 3-4° C at 
0% R. H. (23.2, 24.2, 25.1, and 25.4° C, respectively). Prior acclima- 
tion was significant only on S. xyloni , and on S. invicta collected in 
the winter. The differences in the responses of the four species are 
not clearly correlated with their ecogeographical distributions. 
Acknowledgements 
We wish to thank William P. MacKay, Sherman A. Phillips, Jr., 
Sanford D. Porter, James K. Wangberg, and R. Jeffery Whitworth 
for their comments on the manuscript. We would also like to thank 
the following individuals who aided in the collection of ants: Mike 
Bishop, Lori Braulick, Robin Krai, Mike McCormick, William P. 
Morrison, Lindsey R. Potts, and William Rogers. Lindsey R. Potts 
assisted in the data analysis and Mary L. Peek and Lorie A. Prien 
typed the manuscript. 
This study was supported by the Texas Department of Agricul- 
ture Interagency Agreements I AC (80—8 1 )— 0463, (8 1 —82)— 0806, and 
(82-83)- 1 65 1 . Contribution No. T-10-156, College of Agricultural 
Sciences, Texas Tech University. 
Rhferhnchs 
Banks, W. A., C. S. Lofgrkn, D. P. Jouvenaz, C. E. Stringer, P. M. Bishop, D. F. 
Williams, D. P. Wojcik, and B. M. Glancky, 1981. Techniques for collecting, 
rearing, and handling imported fire ants. U. S. D. A., Sci. Education Admin., 
Advances in Agric. Tech., Southern Ser., No. 21, pp. 1-9. 
Brian, M. V., 1973. Temperature choice and its relevance to brood survival and 
caste determination in the ant Myrmica rubra L. Physiol. Zool., 46(4): 245-252. 
Bull, E., and R. W. Mitchell, 1972. Temperature and relative humidity 
responses of two Texas cave-adapted millipedes, Cambala speobia (Cambalida: 
Cambalidae) and Speodesmus bicornourus (Polydesmida: Vanhoeffeniidae). 
Internat. J. Speleol., 4: 365-393. 
