Ants: prohibition of propagation as a message on the egg

Queen's eggs make infants infertile

Ants worker eating an ice © University of Würzburg
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In ant colonies, the monopoly of reproduction lies with the queen. As long as she is there, the workers do not lay eggs. The trick: The queen gives a signal that keeps her subjects infertile. Researchers from the Biocenter of the University of Würzburg have now identified this signal: The queen writes the order to refrain from any propagation in the state on their eggs. About it reports the magazine PNAS.

In the case of ants, there is a strict division of tasks: The subjects have to work while the queen is responsible for the reproduction. If the workers were also busy laying eggs, it would put a strain on colony productivity. That is why the ruler suppresses the reproductive capacity in her empire.

Annett Endler and Jürgen Liebig from the Würzburg Biozentrum have now found in laboratory experiments with carpenter ants (Camponotus floridanus): The queen herself does not have to be present to keep the workers infertile - this task is done by their eggs. The royal products are marked with a mixture of hydrocarbons that prevent the fertility of the workers. "The mixture consists of more than 30 components, 15 of which are exclusive to the queen, " says Liebig.

That the royal command is delivered with the eggs, makes sense. The investigated ants divide their colonies into several branches, which can be up to a meter apart. So not all workers have contact with the queen - but to their eggs, because they are transported to all branches. There they indicate that a fertile queen is present in the colony.

The tropical weaver ants live distributed on several nests. They build their dwellings in the crowns of large trees and sometimes extend their empire to neighboring trees. How the queen of a weaver ant colony can keep such a large state in check-breeding technology was so far completely unclear. The Würzburg biologists have now also found a possible explanation for this. display

Incidentally, the horse ants support their own sexual subjugation: the scientists set up several queen-free colonies and then smuggled various eggs into it. If they added eggs from both queens and workers, the ants ate the workers' eggs. However, before the researchers transferred the royal hydrocarbons to the common eggs, they were not eaten. In it, the Würzburgers see proof that it is indeed these signaling substances that uphold the regent's reproductive monopoly.

(Bavarian Julius-Maximilians-University Würzburg, 03.03.2004 - NPO)