A species of ant ( Temnothorax nylanderi ), which normally lives on logs, in colonies of between 100 and 200 workers, could well have signed a kind of Faustian pact . Specifically, a pact with a recently identified parasite that seems to give eternal youth to ants in a forest in Germany .
It keeps them young, preserving their soft outer shells and distinctively tawny hue. And, in addition, it lengthens their life (from weeks to several months, even longer), as if the parasites were working in an anti-aging clinic where the elixir of eternal youth is dispensed. However, as in any Faustian pact, a tribute must be paid. And the ants pay two .
Temnothorax nylanderi and her two curses
The ants are parasitized by a tapeworm found in the droppings of woodpecker ( Anomotaenia brevis ), on which it sometimes feeds. The tapeworm, like a good mutualistic parasite, stays inside the ant for the rest of its life. And then, as if they have turned into vampire ants that have just been bitten by Dracula, the infected ants turn pale and remain young .
Researchers have found that these parasitized ants can at least live extra months, but could perhaps stay that way for two decades. The difference with her non-vampirized sisters is very significant, because they barely live for only a few weeks or a few months . In addition, perhaps because of their appearance or their youth, they stop working, as aristocrats, and begin to be cared for, fed and transported by the rest of the colony. They are eternal ants that can even rise above the queen ants.
However, this evolutionary advantage brings with it two problems.
In the first place, colonies where there are parasitized ants have to work harder. Imagine a society in which the majority live on social benefits: finally, female workers die earlier from overwork. Second, the tapeworm manipulates the minds of the parasitic ants to return to the woodpeckers, reproduce and have the eggs expelled again in the droppings so that other ants are parasitized. So when a woodpecker appears, the eternal ants are not afraid, they do not escape. They allow themselves to be eaten .
Tapeworms of this species cannot mature into adults and produce eggs until their host ant is consumed by a bird, a fate that insects in full possession of their faculties try to avoid. But ants that hang around all their time are easy prey; long-lived hosts that are pampered have a high chance of surviving until eaten. Down to the molecular level, the parasite is pulling the strings .
Sara Beros , a former Foitzik doctoral student and first author of the study describing this finding, has opened the abdomen for Temnothorax and has counted up to 70 tapeworms inside. From there, the worms can release a mix of proteins and chemicals that match the ant’s core physiology, likely affecting the hormones, immune system, and genes of its host .
What they accomplish appears to be a rough pantomime of how queen ants reach their mind-boggling lifespan, a feat that humans still don’t understand. Nature, once again, is fascinating.