DNA analysis published in the journal IMA Fungus reveals that parasitic Cordyceps fungi live inside surrounding mosses as well as parasitized insects. This suggests a second life stage that may help the pathogen survive when insect hosts are scarce and explains why hosts bite mosses before dying.
Parasitic fungi in the Cordyceps
genus occupy a familiar space in popular culture and nature documentaries. Beyond their standard portrayal, new scientific findings show these organisms maintain a hidden phase in their life cycle. According to a paper published in the journal IMA Fungus, DNA analysis identified the exact same fungus in both parasitized insects and the mosses surrounding them.
From Carpenter Ants to Mossy Habitats in IMA Fungus
When spores attach to a target insect—such as a carpenter ant—they germinate and spread through the host body via long tendrils known as mycelia. This infection process transforms the host into a zombie slave, compelling the insect to climb to the top of the nearest plant and clamp its jaws in a death grip around a leaf or twig.
The recent DNA discovery published in IMA Fungus introduces an evolutionary twist to this dynamic. Finding the fungus inside surrounding mosses suggests a second life stage where the pathogen lives directly inside the moss. Scientists indicate this may be an evolutionary adaptation enabling the fungus to survive periods when insect hosts are scarce. Furthermore, this moss-dwelling phase could explain why infected host species appear to prefer biting into mosses during their final death throes.
Pop Culture Fascination and Scientific Reality
The intricate biology of these pathogens has captured public attention, notably infiltrating popular culture via the zombie-apocalypse video game The Last of Us (2013) and its television adaptation, where a parasitic fungus mutates to infect humans. Researchers study real Cordyceps to uncover the origins and intricate mechanisms underlying pathogen-based diseases.
The entire natural infection process takes between four to 14 days. During this period, the fungus slowly devours the ant before sprouting through its head in one final indignity. Bulbous growths on the ends of the mycelia ultimately burst, releasing even more spores into the air to infect additional unsuspecting insects.
Mandibular Control Mechanisms Uncovered by Prior Studies
Understanding how the fungus manipulates its host has been the focus of prior research. A 2017 study revealed that fungal cells form an elaborate, interconnected three-dimensional network that allows them to communicate and exchange nutrients. Through this network, the cells effectively cut the brain off from the rest of the ant’s body to control its behavior.
Additional research published in 2019 clarified that the fungus does not directly attach to the infected ant’s brain. Instead, it breaks apart the membrane covering jaw-muscle fibers. This action generates contractions strong enough to damage or destroy the muscle filaments that slide past each other during normal muscle contraction, locking the mandibles into their characteristic death grip.
