DISTRIBUTION OF INHIBITORY QUEEN PHEROMONE 
AMONG VIRGIN QUEENS OF AN ANT, 
SOLENOPSIS INVICTA 
By A. Ann Sorensen 1 ' 3 , David J. C. Fletcher 2 , and 
S. Bradleigh Vinson 
Introduction 
While they remain in the parental nest prior to mating flights, 
sexually mature virgin queens of the fire ant, Solenopsis invicta 
Buren, are prevented from shedding their wings and becoming 
reproductively active by means of an inhibitory primer pheromone 
produced by the mother queen of the colony (Fletcher and Blum 
1981a; 1981b; 1983). This pheromone is relatively nonvolatile and is 
transferred to virgin queens through physical contacts between col- 
ony members (Fletcher and Blum 1981b). When removed from the 
source of pheromone by separation from the mother queen, some 
virgin queens dealate in as little as 12 h (Fletcher and Blum 1981b). 
Hence, inhibitory signals must be transferred frequently to each 
virgin queen. 
The production and transfer of inhibitory signals by the queen 
honeybee, Apis mellifera, illustrates the complexity of queen- 
worker communication. In 1954, Butler hypothesized that the inhib- 
itory pheromone of the queen honeybee is distributed through food 
exchange among the workers. A second hypothesis, by which 
workers contacting a queen pick up queen substance on their bodies 
and then function as “substitute queens”, was proposed by 
Verheijen-Voogd (1959). Although neither hypothesis has been dis- 
proved, most of the evidence supports surface transport as the 
primary mechanism of pheromone transfer (Velthuis 1972; Butler 
1974). Recently, Seeley (1979) showed that physical contacts 
between the workers and a relatively small number of “messenger 
'Department of Entomology, Texas A & M University, College Station, Texas 77843. 
^Department of Entomology, University of Georgia, Athens, Georgia 30602. 
'Current address and correspondence: Dr. A. A. Sorensen, Agriculture and Envir- 
onmental Sciences Division, Department of Agriculture, P.O. Box 12847, Austin, 
Texas 78711 
Manuscript received by the editor October 25, 1984. 
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