Finley Ohrstrom is a Reserva Youth Council member, a musician, and budding (or should I say sporing) mushroom enthusiast. You can follow him on Instagram at @huckfinmusic. Photo by @jonescreativeco.

Of Ants and Spores: Big Drama on a Small Scale

Written by Finley Ohrstrom

The human eye detects an estimated 0.0035% of visible light, and even in this sliver of sight and in the best of conditions, an adult is blind to anything measuring less than 30 microns, or 0.03 millimeters in size. While our intellect is impressive with what it's enabled us to achieve, our limited perception can blind us to some of the most epic dramas that are currently unfolding on our planet.

This particular drama starts with an ant. Or does it start with a mushroom—or is that where it ends? For cyclical mother nature, ends and beginnings don't really exist, and so I will start where I like, and that is with a spore. This spore is one of the most insidious predators on the planet: as it prowls passive rainforest air currents, Hannibal Lecter takes note. Our spore is on its first great migration, from the heights of the forest canopy, down to the teeming forest floor. One spore out of one billion, ejected out into the nothing of it all; falling, falling, falling until it finds a protruding piece of vegetation upon which to land, and begin its hunt ...

Days pass—maybe weeks—but our predator sits with the patience of a spider; the cunning of a snake. So much happens in a rainforest; nothing is still and nothing is preserved; the only things sacred are change and balance. Because of this, birds sing, flowers are beautiful, and a foraging carpenter ant walks across a leaf, stepping on the microscopic assassin spore of the Ophiocordyceps unilateralis. The spore germinates. Having finally found the proper nutrient base for its growth, it extends out a hyphae towards its prey. This excretes an exudate that softens the hapless victim's exoskeleton, allowing a hyphal strand to penetrate its body.

Mitsosis after mitosis, our hungry hunter hits with a litany of hyphal strands, together branching out and then reconnecting to form a feasting matrix throughout the internal organs of the ant. By now, our victim knows that something is wrong, but resistance is futile: if its colony identified the infection, they would choose only to carry the ant as far away as possible to reduce the risk of any further cases. They've seen how this story ends before, and they want no part in it at all.

Photo by David Hughes via flickrA parasite that fights the zombie-ant fungus has yielded some of its secrets to an international research team led by David Hughes of Penn State University. The research reveals, for the first time, how an entire ant … — Photo by David Hughes via flickr
A parasite that fights the zombie-ant fungus has yielded some of its secrets to an international research team led by David Hughes of Penn State University. The research reveals, for the first time, how an entire ant colony is able to survive infestations by the zombie-ant fungus, which invades an ant's brain and causes it to march to its death at a mass grave near the ant colony, where the fungus spores erupt out of the ant's head. This photo shows a zombie ant with the brain-manipulating fungus (Ophiocordyceps unilateralis s.l.) having been castrated by an hyperparasite fungus (white with yellow material). This is no longer a threat to the ants.

By now, our spore is no longer a spore but a mycelial matrix: the feeding body of the organisms that produce the familiar reproductive bodies called mushrooms. This mycelium's hunger is ferocious: right now it accounts for some 25% of the cells in the ant, and has worked its way into its head. Not content to simply siphon off digestion like other more benign parasites, the mycelium exudes enzymes that further break down internal, organic structures, killing its host from the inside out.

But a quick death is too kind an offer from the likes of this psychopathic fungus, and there is much more to be done. Around 50% mycelium seems to be critical mass for the ant: at this point it loses itself; forfeits its body; becomes a marionette to Ophiocordyceps unilateralis' hyphal strings. For a long time the ant's behaviour will have been untoward, but now its body is owned, bought and paid for by the patience of the spore and the precision of its attack. The fungus walks its newly tamed carcass upwards, to a place that provides a good vantage point for sporelation, all the while progressively encouraging neurotransmitters that slow the ant down. Once at the desired location, the fungus interacts with the ant's set of genes, controlling lockjaw which causes the necessary muscles in the ant's mouth to deteriorate and the ant to clamp down, holding its body firmly to the fungus' vantage point.

Now it's time for it to eat up, and lay down some finishing touches before the big event. The fungus further anchors itself to its perch with hyphal strands, and suppresses the immune system of the technically living ant. This allows the fungus uninhibited access to a smorgasbord of internal organs—it feasts while simultaneously hardening the ant's exoskeleton, which serves to protect the feeding mycelium from its own predators.

Alas, the time has come. Patience and cunning have paid off, and it's finally time for the fungus to pass on its cruel and effective legacy. At the top of the ant's skull forms a hyphal knot, a dense tangle of hyphal strands that thickens into a primordia, then extends out, cell by cell, until it becomes a mushroom. This mushroom's perithecium contains one billion invisible ascospores, each one ready to hunt; each one ready to kill; each one ejected out into the passive currents of the rainforest; agents of balance, and of change.

Ophiocordyceps sp. Tosohatchee Wildlife Management Area, Orange County, Florida, USA. Photo by Katja Schulz via flickr. — *Ophiocordyceps* sp. Tosohatchee Wildlife Management Area, Orange County, Florida, USA. Photo by Katja Schulz via flickr.