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Sorensen, Busch, & Vinson — Solenopsis invicta 
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The queen continued to receive food regardless of which subcaste 
members were present, indicating that all workers were responsive 
to her needs. However, queens received more food from foragers 
than from nurses or reserves. This may have been related to the 
tendency of older ants to regurgitate food more readily than 
younger ants (Mirenda and Vinson 1981). It may also have been due 
to the presence of more food, increasing the probability that the 
queen would be fed (Howard and Tschinkel 1981). We do not know 
which subcaste members feed the queen in field colonies. Access to 
the queen, normally sequestered near the brood, may be limited to 
nurses and reserves. However, Brian and Jones (1980), in their 
studies with M. rubra, found that foragers associate with and pass 
food directly to the queen. They also cite similar findings for 
Oecophvlla longinoda and Lasius niger. They feel that it may be a 
general phenomenon in all ants that foragers are more queen 
oriented and thus more susceptible to her influence over behavior 
than nurses. 
In summary, these experiments indicated that the normal 
sequence of response behavior to food in fire ant workers could be 
altered. This ability of workers to switch to a new behavioral role in 
response to colony needs insures a steady flow of food to the queens 
and larvae. For fire ants, behavioral flexibility of workers greatly 
increases the chances of colony survival. 
Acknowledgments 
The authors would like to thank Drs. Les Greenberg, Gale Smith, 
and David J. C. Fletcher and two anonymous reviewers for their 
helpful suggestions on early versions of this manuscript. The gamma 
radiation counter was kindly provided by Dr. Max D. Summers. 
This manuscript was approved as TA-19659 by the director of the 
Texas Agricultural Experiment Station. This research was supported 
in part by the Texas Department of Agriculture Agreement 
IAC'(82-83)0982. 
References 
Brian, M. V. and R. M. Jones. 1980. Worker population structure and gyne 
production in the ant Mvrmica. Behav. Ecol. & Sociobiol. 7 : 281-286. 
Cammaerts-Tricot, M. C. 1974. Production and perception of attractive phero- 
mones by differently aged workers of Mvrmica rubra (Hymenoptera:Formi- 
cidae). Insectes Soc. 21 : 235-247. 
