Cordyceps fungus infiltrate their insect host, where their hyphae then grow into the insect's body and absorb nutrients from non-essential organs while controlling the insect's brain. When the fungus is ready to reproduce, it directs its host to march to a cool, moist location in the forest where spores erupt through the insect's head to spread in the wind. Is it commensalism, mutualism, parasitism, or predation?
The relationship described between the Cordyceps fungus and its insect host is an example of parasitism. The fungus benefits by infiltrating and absorbing nutrients from the insect's body, while the insect is negatively affected as the fungus controls its brain and ultimately leads to its death. The actions of the fungus are solely for its own reproductive purpose, at the expense of the insect host.
