by Konchok (Gengqiu) Gelek (Gelai)
Caterpillar fungus formally known as Ophiocordyceps sinensis, is a fungus endemic to the alpine area in Tibetan plateau and surrounding Himalayas mountain region. It is also known as yartsa gunbu in Tibetan and dongchong xiacao in Chinese, which literally translated as 'summer grass-winter worm'. The fungus infects larvae of the ghost moths (Thitarodes), which live underground feeding on plant roots. When larvae shed their skins in the late summer, they get exposed to fungus in soil and get infected. The infected larvae usually stay underground with head facing upwards. During winter the fungus spreads though caterpillar’s body and slowly kills it, leaving it looking as a mummy. In the spring, the fungus emerges from the soil still connected to the mummified caterpillar. During mid-May to late June, rural people in the Tibetan plateau and sounding Himalayas region, collect the caterpillar fungus. Uncollected yartsa gunbu provide spores that will infect new ghost moth larvae.
Yartsa gunbu is used in traditional Tibetan and Chinese medicine. It is prescribed for lung, liver, and kidney issues. The price for yartsa gunbu has skyrocketed since the early 2000s, which shapes the social-economic aspect of rural people in the Tibetan plateau. The lowest price for yartsa gunbu is $7,500/ 500g, and the top-quality price reaches up to $27,000/ per 500g in 2018. By collecting yartsa gunbu, local people earn more than ten times the annual average income. The generous income from yartsa gunbu enables improvement of education, healthcare, transportation, and housing, and offers an option for leisure time for rural herders and farmers. Indeed, the yartsa gunbu improves the material condition in people's life, but perhaps yartsa gunbu harvest is to blame for abandoning farmlands and declining of pastoralism in rural Tibet.