Ants may be social insects, but when it comes to reproduction, the queen makes sure she’s the only mother.
After all, if the worker ants took time out to lay eggs, the productivity of the colony might suffer.
But how does the queen exercise that authority?
A team of European researchers wondered just that, so they studied Capononotus floridanus, a type of ant living in large colonies.
It turns out the queen ant coats her eggs with a chemical called a pheromone that prevents worker ants from laying their own eggs.
Juergen Liebig and colleagues at Wuerzburg University in Germany set up several colonies with only workers — no queen — and added various combinations of pupae, larvae, and eggs.
In colonies that did not receive queen-laid eggs the workers began to lay their own eggs. When both queen-laid and worker-laid were added to a colony, the ants destroyed the worker-laid eggs.
Only the presence of queen-laid eggs inhibited worker reproduction.
The researchers analyzed the surface of the queen-laid eggs and found they contain a special hydrocarbon blend, very similar to that found on the body of the queen herself.
Adding the chemical blend to the surface of worker-laid eggs prevented the ants from destroying these eggs.
The findings were reported in this week’s online edition of Proceedings of the National Academy of Sciences.
