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 In places where insects are a large problem, the use of fungi has been explored as an alternative to the use of chemicals as a means to control them. The Cordyceps genus of fungi has been studied for this purpose. Cordyceps are abundant in tropical climates, such as in China, Africa, and South America. Within the Cordyceps genus, 400 species have been described, with many that are deadly parasitic to a large variety of insects. These include moths, butterflies, and grasshoppers among many other insects. What makes this fungus so fascinating is that after infecting a host, it has an extremely interesting way of killing and ensuring that it will effectively propagate to a new population of insects: through the use mind control.

Cordyceps unilateralis is the species that targets ants exclusively. Its spores enter ants through their tracheas (where ants breathe) and grow within the ant’s soft tissues while avoiding its vital organs. When the fungus begins to run out of nutrients, it grows into the ant’s brain and secretes chemicals which alter the ant’s perception of pheromones. This manipulates the ant into climbing a plant to the top. At the top, the ant uses its mandibles (the mouth’s appendages) to bite and securely latch itself to the vein of a leaf, creating a distinctive indentation termed the “death grip”. Then, as the fungus invades the ant’s brain, like a scene out of a science fiction movie, out of the insect’s brain slowly grows out a long fungal fruiting body. This fruiting body contains a large collection of spores which, once mature, burst into the environment from its high height in search of new ants to infect. The infectivity of C. unilateralis by this tactic is so great that some researchers have described infected ants as walking graveyards (Pontoppidan et al, 2009).

This death grip has been identified on leaf fossils dating back to 48 million years ago, a testament to Cordyceps’s adaptive prowess (Hughes et al, 2010). However, a little more recently (as far back as the 15th Century), the use of Cordyceps has been documented in human medicinal use (Winkler, 2008).

Believe it or not, the Cordyceps genus, the same fungus that is so parasitic to insects, has been used as a highly valued source of tonic food and medicine in China for hundreds of years. In fact, their popularization came about recently during the 1993 National Games. After three Chinese female athletes broke 5 world records during the games, many expected the athletes to test positive for anabolic steroids. However, no steroids were identified by tests and the athletes’ coach revealed that the consumption of Cordyceps sinensis (and turtle blood) likely gave them an edge over the competition (Mackay, 2001). C. sinensis is the species of the Cordyceps family that infects caterpillar, and their medicinal potential is now under extensive study by Chinese scientists. To date, researchers have uncovered antisenescence, endocrine, hypolipidemic, antiatherosclerotic, and sexual function-restorative activities as part of their medicinal advantages (Zhu, Halpern & Jones, 1998). Papers have also been published noting C. sinensis may protect the liver from damage, have anti-depressive effects, and be beneficial for diabetics with insulin resistance (Ko et al, 2009). A large body of scientists have been devoted to the fungus’s ability to inhibit tumor growth, including its mycelial antitumor sterols (Xiao, 2010)

Clearly, the Cordycep fungi are an anomality of the fungal Kingdom. In it encompasses viable solutions to both the fields of biological insect control and to human medicinal use, when taken together, seem to be a strange and weird combination. Nonetheless, this is a fungus of which humans can take advantage of, and continuing research is indeed underway.

(FYI: For a video on the mind controlling effect of Cordyceps unilateralis on ants, see: http://www.youtube.com/watch?v=vgkL8PulPdE)

Hughes, PH., Wappler, T., Labandeira, CC. 2010. Ancient death-grip leaf scars reveal ant–fungal parasitism. Biology Letters.

Jia-Shi Zhu, Georges M. Halpern, Kenneth Jones. 1998. The Scientific Rediscovery of an Ancient Chinese Herbal Medicine: Cordyceps sinensis Part I. The Journal of Alternative and Complementary Medicine, 4(3): 289-303

Ko, WS., Hsu, SL., Chyau, CC., Chen, KC., Peng, RY. 2009. Compound Cordyceps TCM-700C exhibits potent hepatoprotective capability in animal model. Fitoterapia, 81 (1): 1-7

Mackay, D. 2001. Ma's army on the march again. The Guardian, July 24 2001

Pontoppidan, MB., Himaman, W., Hywel-Jones, JL., Boomsma, JJ., Hughes, DP. 2009. Graveyards on the Move: The Spatio-Temporal Distribution of Dead Ophiocordyceps-Infected Ants. PLoS One, 4(3), 1-1-.

Winkler, D. 2008. The Mushrooming Fungi Market in Tibet exemplified by Cordyceps sinensis and Tricholoma matsutake. In the Shadow of the Leaping Dragon: Demography, Development, and the Environment in Tibetan Areas

Xiao, G., Miyazato, A., Abe, Y., Zhang, T., Nakamura, K., Inden, K., Tanaka, M., Tanno, D., Miyasaka, T., Ishii, K., Takeda, K., Akira, S., Saijo, S., Iwakura, Y., Adachi, Y., Ohno, N., Yamamoto, N., Kunishima, H., Hirakata, Y., Kaku, M., Kawakami, K. 2010. Activation of myeloid dendritic cells by deoxynucleic acids from Cordyceps sinensis via a Toll-like receptor 9-dependent pathway. Cellular Immunology, 263(2): 241-250