The Fungi That Turn Insects into Zombie Hosts
Student Summary by Audrey Kim
Original Source: Charissa de Bekker, William C. Beckerson, and Carolyn Elya. Science Journal for Kids and Teens, November 2023
https://www.sciencejournalforkids.org/wp-content/uploads/2023/11/zombie_article_lower_level.pdf; https://journals.asm.org/doi/10.1128/mbio.01872-21
Image created by Audrey Kim
Abstract
Background
Just like all other living organisms, fungi want to spread their generations. In order to accomplish that task, they can change an insect's behavior, just as if they were possessed. In their case, fungi use small cells called spores. In order to spread them farther, they infect insects to use them as hosts. By changing the host's behavior, the fungi eventually make the host go to the right place before killing it.
Objective
These zombie-making fungi each evolved independently, and each one had its own way of controlling insects. However, all infected insects acted and did similar things. Scientists wanted to know how the fungi did that and why this strategy was so popular among them.
Method
Researchers first observed the information that was already known on the zombie-making fungi. It seemed like the steps were simple: the fungal spores entered the ant nest and infected the working ants. Then the infected ant bit onto a plant to attach itself. Finally, a full-grown fungus came out of the dead insect and started the cycle again.
Results
It turns out there were two ways for a fungus to change the insect's behavior. First, they change the physical features of the host, like spreading their wings so that they won't get in the spores' way. Another physical change is when a fungus that takes over some of the organs of the host. Second, the fungi release chemicals that affect the host's brain. This acts like a drug and makes the host do strange tasks.
Conclusion
These fungi that control the insect (host)'s behavior are an incredible example of how organisms adapt in nature. From a certain point of view, it might seem violent and selfish, using others for their own profit. However, this can also be seen as a result of evolution in different species through millions of years. Every living thing has its own strategies in life, and the intersection between species can appear in any type of condition.
