When we visited Amdo (Qinghai Province) in October, we saw yartsa gunbu for sale everywhere we went. There was a particularly large display at the Tibetan Medicine Museum in Xining. We asked what it was and got the answer "dried caterpillars" and while I have seen a lot of strange things being eaten or used as Chinese Medicine while here in China, I just couldn't bring myself to believe these were dried caterpillars. They were too uniform in color. Each one had a stalk growing out of what looked like the head. And they were ridiculously expensive. So I decided, on my own, that they were some sort of rare root that highly resembled a caterpillar.
Today, I discovered the truth. It turns out that the questionable item is a little bit of both - caterpillar and root. The yartsa gunbu, meaning "summer grass, winter worm" in Tibetan, is a type of fungus. The spores attach themselves to the larva of a ghost moth that spends its formative weeks underground. The fungus eats the moth larva from the inside and then takes the form of the larva. A stalk grows out of what used to be the larva's head out into the open air above ground.
The fungus is prized in traditional medicines here, both Chinese and Tibetan, and brings a high price at market. It only grows in the high altitude of the Himalaya and the Tibetan plateau and farming it has so far been unsuccessful so Tibetan gatherers head out to dig the things up every spring. Local people who harvest the worms add significantly to their income by selling what they find.
It's a shame I didn't figure out what I was looking at it while we were in Xining, but I'm glad now I know. Hopefully I'll get back that direction some day and learn more about it.
These excellent National Geographic articles are the source for this blog post.
- Tibet's Golden "Worm" by Michael Finkel
- Caterpillar Fungus Has Anti-Infammatory Properties by Nicholas Mott