Queen attractiveness to workers in the polygynous form of the ant Solenopsis invicta (Hymenoptera: Formicidae)

We found that queens in laboratory colonies of the polygynous form of the imported fire ant, Solenopsis invicta Buren, are aggregated. No fighting or competitive behavioral interactions between queens were observed. We then examined the response of workers to individual queens in an effort to determine if queens within the same colony were equal in worker attractiveness. When queens were separated and workers were allowed to choose among them, 1 queen generally attracted >70% of the workers and brood. However, the difference in worker numbers attracted to remaining queens in the colony was not significant. The difference in queen's attractiveness to workers might be the result of a quantitative variation of queen pheromone. Increasing the number of queens and size of the colonies still resulted in most workers consistently responding to one of the queens. When the queen that attracted >70% of the workers was removed, >70% of the workers responded to another queen. When the removed queen was returned to the colony, she was again chosen by >70% of the workers.