PARASITES

Museum of Jurassic Technology, upper balcony of beastiary exhibit (photo by Ryan Schude)

While watching a documentary on Werner Herzog, I see him walk into the Museum of Jurassic Technology.  I stumbled on to it in the late 80s and am amused to now discover Werner considers it a treasure.  Long before Culver City was converted to a traffic vortex, I made countless visits to Jean and John's place - practically next door neighbors.  It was there in a dimly lit corner that I was first introduced to Zombie ants.   I had passed by the display several times without giving it more than a quick glance.  The display consisted of a glass window through which one could peer into a waste-basket-sized interior that appeared empty, save for a loose collection of yard trimmings. Eventually, curiosity led me back to check out the brief type-written paragraph posted at the base of the viewing window.  As soon as I read something about a carpenter ant I tried to see if there were any crawling about in the twigs and leaves.  

For several minutes my focus shifted repeatedly back and forth between the paragraph and the vegetation.  I couldn't spot any movement and assumed that the display was undergoing repairs or worse, the ants had died.  Then I saw it.  There had been no movement because the ant was dead, and no wonder.  There was a ridiculous Tootsie Pop shaped spike sticking out of its head.

The paragraph explained that the spike was caused by a type of a parasitic fungus (Ophiocordyceps Unilateralis) that has evolved to target a species of carpenter ant as its host.

These particular ants make their nests high up in the canopy of tropical forests but occasionally visit the jungle floor where fungal spores lay in wait.  The spores utilize a combination of enzymes to pierce and infiltrate the ant's exoskeleton, eventually taking over control of the ant's central nervous system.  The infected ant proceeds to climb up back to the nest but stops about a foot off the ground where, induced by compounds secreted by the fungus, locks its jaws on a leaf.  Interestingly, a foot above the ground turns out to be the sweet spot for spore growth in terms of temperature and humidity.  It is here, with a death grip on the leaf, the ant dies and the fungus exudes the physical and chemical means to not only firmly secure the carcass but ward off microbial and scavenger attacks.  A week or so later the fungus sprouts the TooTsie Pop from the ant's head, then ruptures, dispersing fresh spores to the forest floor to lay in wait for another unsuspecting ant to come along.

Years later I learned of another parasite (Ribeiroia ondatrae) that employs a more intricate chain of events that cycles through snails, tadpoles, frogs and birds.  A free-swimming form of the parasite is released by infected snails and finds its way to tadpoles where it manages to interfere with the development of the hind limbs.  

This results in mature frogs with deformed legs that hinder their mobility, rendering them easy prey for various water birds. The birds become infected and flying over marshes, drop eggs from the parasite with their feces that proceed to infect a new crop of snails and perpetuate the cycle.  

I was still quite naive when I learned of the zombie ants and the deformed frogs.  Burma was still Burma, Pluto was still a planet and I hadn't been confronted yet with the notion that the globe was civilization's host.  The veil was lifted for me by Paul Theroux in his travelogue entitled The Great Railway Bazaar.  

While visiting along the coast of Ceylon (currently Sri Lanka) in the early 1970s, Theroux inquired about the ever-present billowing smoke that he encountered.  He was informed that recent government policies had banned various imports, including among them, cement.  A new industry sprang up to address this by blasting coral from reefs with dynamite and then burning it to extract lime and calcium carbonate - key ingredients for manufacturing cement.  Unfortunately, the damaged reefs led to significant losses to the shoreline and threatened the fishing industry.  The government launched a program to restore the balance by replacing the lost coral with artificial reefs made of cement.  Since no cement could be imported, the reefs dynamited to make cement, must themselves be replaced by the same process.  Certainly providing evidence that human endeavors conform with fungal life cycles by serving no purpose other than to prolong their own existence.