DENMARK: In a chilling twist of nature’s intricate dance, researchers from the University of Copenhagen and Wageningen University have recently revealed the eerie control that parasitic lancet liver flukes exercise over infected ants, effectively turning them into obedient pawns in a survival game.
The Zombie ant phenomenon
The star of this parasitic horror show is the lancet liver fluke known as Dicrocoelium dendriticum. Once it infiltrates its unwitting host, the Formica polyctena ant, it orchestrates a sinister symphony of behavioral manipulation that has researchers and nature enthusiasts alike astounded.
The parasitic takeover
Upon infection, several hundred Dicrocoelium dendriticum parasites invade the ant’s body. However, only one of these crafty invaders makes its way to the ant’s brain, where it seizes control over the ant’s behavior. The rest of the parasites wisely conceal themselves in the ant’s abdomen, shielded from the host’s stomach acid. This ‘zombie’ fluke, as it’s aptly called, eventually sacrifices itself for the greater good of the others.
Playing the survival game
What’s truly remarkable is how these parasitic marionettists play the game of survival with their host ants. Over 13 non-consecutive days in the Bidstrup Forests near Roskilde, Denmark, researchers Dr. Brian Lund Fredensborg and Simone Nordstrand Gasque observed a startling 1,264 individual ants exhibiting the altered behavior. To better track the ants, a subset of 172 infected ants was individually marked.
This macabre game of survival isn’t just a matter of chance. The infected ants, under the puppetry of the liver fluke, engage in a strategic dance. When temperatures are low, they ascend the blades of grass and firmly clamp their jaws onto the tips, effectively making themselves more visible to potential grazers such as cattle and deer.
However, as the sun’s rays scorch the landscape, the infected ants abandon their precarious perches and crawl back down, seeking refuge from the heat.
Sophistication beyond imagination
Dr. Brian Lund Fredensborg from the University of Copenhagen remarked, “It makes sense for the ants to be high up in the grass for when cattle or deer feed during the cool morning and evening hours before moving back down to avoid the sun’s harmful rays. The parasite is more advanced than we first thought, according to our discovery.”
This eerie example of parasitic manipulation is not an isolated incident. Throughout the animal kingdom, numerous parasites exert control over their hosts’ behavior, often with dire consequences for the hosts themselves.
A larger ecological picture
Dr. Fredensborg emphasizes the importance of understanding these parasitic dynamics in nature, stating, “Despite the fact that scientific sources claim that parasitism is the most prevalent living form, parasites have historically not received much attention. This is partly because parasites are so challenging to investigate. However, parasites play a vital role in biodiversity and, by altering the behavior of their hosts, can influence who consumes what in the natural world. Thus, it is crucial that we comprehend them.”
In the shadowy realm of parasitism, where creatures manipulate the minds of their hosts to serve their sinister purposes, the lancet liver fluke, Dicrocoelium dendriticum, has taken center stage.
Its ability to choreograph the behavior of infected ants in response to temperature changes is a testament to the mysterious and often chilling intricacies of the natural world. This study is a stark reminder that even the tiniest of organisms can wield immense power in shaping the delicate balance of ecosystems.