Zombie Fungus (Ophiocordyceps Unilateralis) Annie Wibking Botany, APSU

Zombie Fungus (Ophiocordyceps Unilateralis) Classification Kingdom – Fungi Division – Ascomycota Class – Sordariomycetes Order – Hypocreales Family – Ophiocordycipitaceae Genus – Ophiocordyceps Species – O. Unilateralis Attack of the Killer Fungus (make sure you are connected to and internet browser & click picture to view video) July 22, 2012 Footer text here

Summary O. Unilateralis is the “zombie” fungus. It infects certain species of carpenter ants in the tropical rain forests of Brazil and Thailand. Its hyphae invade the softy tissues then the stroma (or stem) sprouts from the head of the ant. The ant eventually dies within 4-10 days. The fruiting bodies grow from the head of the ant and release spores to start the process again. (Penn State. 2011) July 22, 2012 Footer text here

Life Cycle The zombie fungus was first discovered by a British naturalist, Alfred Russell Wallace, in 1859. The fungus “brainwashes” the ants. The fungus makes the ant to fall on leaves about 10 inches from the ground where the temperature is 68-86 F and the humidity is 94-95 %. This is a perfect environment for the fungus to grow. Somehow the fungus programmed the ant to bite the leaf at solar noon. The ants die and the fungus grows. (Hughes 2012) July 22, 2012 Footer text here

Life Cycle Process of 4-10 days: spores attach to ant – breaks through exoskeleton due to enzymes propagation of fungus within the ant – produces chemicals to change behavior of ants causing convulsions and attachments to leaf vein mycelia– invade soft tissues of ant leading to atrophy of jaw muscles and death of ant stroma or stem – sprouts from head of ant several days later – it secretes antimicrobials fruiting bodies appear – release of spores. Step 1 spores attach to ant Step 2 propagation of fungus Step 3 atrophy & death of ant Step 4 secretes antimicrobials Step 5 release spores July 22, 2012 Footer text here

Morphology The fungus appears as a stalk arising from the head of the ant. Spore bearing sexual structures then grow horizontally. The stalk is darkly pigmented. Fossil evidence has been found on the leaves of plants that grew in Germany 48 million years ago. (Sample 2010) A dead ant manipulated by a species of so-called "zombie ant fungus" clings to a twig in a South Carolina forest. Newly published Penn State research represents the first extensive study of zombie ants in North America. Image: Hughes Lab, Penn State July 22, 2012 Footer text here

Adaptations and defensive behavior The ants have evolved to the point that healthy ants will carry dying ants far away from the colony to prevent further spore exposure. An unidentified fungus hyper parasite has appeared that attacks the zombie fungus as the stalk emerges from the ant, preventing release of spores. Because of the hyper parasite only 6-7 % of the spores remain viable, therefore limiting the devastation of the carpenter ants. The zombie fungus and ants of the tropical forests have reached an ecological balance. (Hughes 2012) To study the mechanism zombie ant fungi use to manipulate their hosts, researchers infected ants in a lab and studied interactions between the fungus and ant brains. Image: Hughes Lab, Penn State July 22, 2012 Footer text here

Potential benefits The research team at Penn State is working on how the fungus might control insects, as an alternative to pesticides. Also, the O. Unilateralis contains various chemicals that are being investigated as potential leads to molecules that produce anti- tumor or immunomodulatory activity. O. Unilateralis produces various naphthoquinones that could be used as dye in food, cosmetics or pharmaceuticals. (Pacchioli 2012) July 22, 2012 Footer text here

References Harmon, Katherine (2009). Fungus Makes Zombie Ants Do All The Work. Scientific American, a Division of Nature America, Inc. https://www.scientificamerican.com/article/fungus-makes-zombie-ants. Hughes, David (2012). The Zombie-Ant Fungus Is Under Attack. The Pennsylvania State University. http://science.psu.edu/news-and- events/2012-news/Hughes4-2012. Penn State. (2011, May 9). Zombie ants have fungus on the brain. ScienceDaily. Retrieved November 15, 2016 from sciencedaily.com/releases/2011/05/110509065536.htm. Pacchioli, David (2013). Getting to the bottom of the zombie ant phenomenon. The Pennsylvania State University. http://news.psu.edu/story/277383/2013/05/21/research/getting-bottom- zombie-ant-phenomenon. Sample, Ian (2010). Zombie ants controlled by parasitic fungus for 48m years. Guardian News and Media Limited. https://www.theguardian.com/science/2010/aug/18/zombie-carpenter-ant- fungus. July 22, 2012 Footer text here