Zombie Ant Fungus: Latest Research

In 1995 I read a book called Mr. Wilson’s Cabinet of Wonders: Pronged Ants, Horned Humans, Mice on Toast, and Other Marvels of Jurassic Technology by Lawrence Weschler. It introduced me to the amazing Museum of Jurassic Technology in Los Angeles, about which you can read more here, but also to the world of fungi that turn their hosts into zombies who live only to create more zombies.

There are a surprisingly large number of examples of such fungi. But the general pathology is the same: an insect consumes fungal spores and gradually alters its behavior to make it a better distributor for the next generation of spores, such as by climbing up a tall plant and clinging to the underside of a leaf so that spores fall onto the ground below. Then the insect dies, the fungus keeps growing until it bursts out and generates spores, and the cycle continues.

Ants infected by this fungus sprout horns. The fungus grows until it actually ruptures the carapace, then keeps growing until horns form and those horns in turn release the spores.

It’s a fascinating scenario. I’ve read more about this and related fungi over the years, and used it as the basis for my campaign setting Horns in the Hill for Robin D. Laws’ Hillfolk. It’s also the foundation of my young-adult novel Magonia’s Shadow, which I’m currently working on.

So in late 2013 when an actual scientific research project to study a zombie ant fungus showed up on Experiment.com — a sort of Kickstarter for academic science  — I was an enthusiastic backer. Dr. Charissa de Bekker proposed to study the genetics of how the fungus manipulated behavior in carpenter ants.

After a great deal of time and effort, Dr. Bekker and her colleagues have published their findings. You can read their entire paper for free online as well as a shorter summary article written more for non-scientists.

My interest in this work is, of course, from a creative perspective as a writer and game designer. As soon as the paper went online, I combed through it for fascinating and even creepy tidbits about this fungus and its lifecycle.

Here are my favorite bits:

1. Dr. Bekker found that the fungus manipulates the ant’s internal body clock. All infected ants in the experiment manifested their climbing and biting behaviors at the same time of day, and died at the same time of day, basically acting in unison.
2. The fungus produces alkaloids that mimic neurotransmitters such as serotonin. Similar alkaloids are produced by the ergot fungus which famously infested rye crops in the middle ages and caused mass hallucinations in humans among other symptoms. Therefore it is conceivable that the fungus induces hallucinations in the ants as well.
3. The fungus changes its secretions over the course of its infection of the host. When it’s time to send the ant climbing up to its final resting place, the fungus secretes different proteins to trigger the desired behaviors. The specific biting behavior, in which the ant bits into the leaf and holds its jaws shut until death, is nothing like typical ant behaviors. Dr. Bekker found specific enzymes created by the fungus that can manipulate neural pathways known to impact both locomotion and mandible operation. In short, the fungus has evolved an incredibly specific vector of attack on the ant to result in this unusual behavior.
4. Infected ants stop following the chemical trails laid down by fellow ants and which typically guide their journeys in the forest. Instead they stay closer to their colony, awaiting their fate. They become antisocial.
5. The fungus generates enterotoxins that kills cells and atrophies muscles. The ant gradually weakens, slows, and dies helplessly, unable to move. After death, the fungus keeps growing out of the corpse in the form of horns emerging from the head.

I’m grateful to have the opportunity to support this scientific research. And the results are nothing short of amazing — this fungus is a seriously advanced piece of genetic technology.

I expect to incorporate some of these concepts in my novel Magonia’s Shadow. Speaking of which, here is a relevant excerpt. The book is about a community whose culture and belief system have been shaped by a long-term fungal infestation:

      Marla saw them first. She went to check on her father when he slept late one morning and saw the first little growths emerging from underneath the fresh moss. She carefully removed the poultices and there they were: the red, moist buds and sprouting tendrils crowning through.

      She started, stepping back quickly in horror. Of course she had seen the horns before on older people in the community when their time was coming. But to see them starting to appear on her own father, unmistakable and raw, was shocking.

      There was no turning back.