When graduate student Adrian Smith, the study's lead author, applied the compound to worker ants in naturally occurring amounts, the ants were attacked by their sisters.
"When we used a different [chemical] that is not specific to these reproductive cheaters, there was no effect," Liebig said. "So it really was the specific compound that identifies them as reproductive cheaters."
Me vs. Us
Les Greenberg, of the University of California, Riverside, said the ability to manipulate ants' chemical signals artificially should also help unravel other types of insect communication.
"The study is a fascinating example of how social insects maintain order in their societies," said Greenberg, who was not involved with the research.
"The analysis of other behaviors, such as dominance hierarchies and nestmate recognition, should be possible with these techniques," he said.
Liebig believes comparisons can be drawn to some extent between ant colony behavior and human social interaction.
"I think it's a characteristic of any society that there's some temptation to cheat," he said.
"In ants we have these same problems: We have colony interests and individual interests," he continued. "If everybody just follows his own interest, the benefit of cooperation would no longer be there."
But Mark Deyrup, a senior research biologist at Archbold Biological Station in Florida, questions whether the findings can be applied so neatly to human social behavior.
"In human societies, those who take on the roles and privileges of a poorly functioning, anointed leader may actually promote societal stability," said Deyrup, who was not involved in the study.
Still, Deyrup described the new research as "impressive," "fascinating," and "particularly commendable for its meticulous tracing of the pathways of cause and effect."
Deyrup, Greenberg, and Liebig all believe fertility-status pheromones could play similar roles in other social insects, possibly including some bees and wasps.
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