An insect-eating fungus could help us fight viruses—and now we know how to grow it

The Cordyceps mushroom, an exotic fungus, grows by infecting insects with its spores. The spores use the animals’ bodies as all-you-can-eat buffets, feasting on their flesh. This parasitic relationship ends only when the spores fully grow and mature, sprouting out and mercilessly killing their hosts. Despite its unorthodox but popular survival method—Cordyceps are the inspiration behind some apocalyptic films and video games—the mushroom has some sought-after medicinal properties. For years, scientists have attempted to replicate this process in the lab, because the mushroom is hard to find in the wild. Using brown rice, a common experimental substitute for bugs, often fell short.