The Last of the Fungus
In eastern Tibet, high in the Himalaya, Tenzin stopped at a cliff edge. He lit another cigarette. In front of us, Mt. Gongga dazzled in spring’s morning light, a dizzying 24,800 feet above sea level. Tenzin is not his real name. His perilous occupation—collecting and selling caterpillar fungus—is fraught with competition and secrecy, and I didn’t want to put him in jeopardy with the local authorities.
Tenzin (a common local name meaning “holder of Dharma”) had reluctantly agreed to show me how to find the treasured fungus. He was in his mid-30s and generally taciturn. But his growing dissatisfaction with my ability to keep up on the trek began to show in his furrowing eyebrows. It was 2016, and I was a first-year doctoral student in search of a thesis. I, too, grew up in this part of the world—my hometown in the Sichuan lowland was only a day’s drive away. But I was naive enough to think that training on an elliptical machine was adequate preparation to hunt caterpillar fungus in person. Whenever I fell too far behind, Tenzin sat down and smoked a cigarette in ostensible boredom.
This parasitic fungus took over the bug’s body and commandeered its brain.
We retreated from the cliff and trekked along steep grasslands. Tenzin stopped at a cluster of dry plant stalks no less than a few inches tall and gestured to me to come over. He pointed to a brown stroma—a bundle of spore-bearing fungal tissue. It looked like a rusted nail sticking up in the soil.
The previous summer, our quarry was an unsuspecting insect spending its larval caterpillar days—on its way to emerging as a ghost moth—in what should be the safe embrace of the earth. Through a process that had remained mysterious, it picked up an unfortunate infection: an insidious and wily fungus called Ophiocordyceps sinensis.
This parasitic fungus took over the bug’s body and commandeered its brain, maneuvering the caterpillar into the perfect place, just below the surface of the soil, before consuming it from the inside. At just the right time in the spring, the fungus blasted a stroma out of the caterpillar’s head and up from the soil.
Tenzin took out a pocketknife and plunged it into the ground next to the stroma. He excavated the “caterpillar” part of the booty. It was eerie: the mandible, complex eyes, three pairs of prolegs—characters I encountered in my entomology coursework, now real, half-covered in soil and dangled under the stroma. Even the exoskeletal segmentation was clear. But the ex-caterpillar was twisted, a sign of suffering in its previous life; the fungal stroma looked sinister and triumphant. Tenzin protectively wrapped the caterpillar fungus in a home-sewn pouch.
Before sunset, we found more than 30 caterpillar carcasses. We
