A biodiversity-rich region of Bhutan is under threat from poachers who are digging up caterpillars infected with a valuable fungus used in traditional Chinese medicine.
The fungus — Cordyceps sinensis — reputedly boosts the immune system of those who eat it. Advocates include world-record holding Chinese athletes.
After the outbreak of SARS in Hong Kong in 2002, the price of the fungus shot up to US$7,000 a kilogramme, half the price of gold.
The sudden popularity has led poachers from Tibet and Bhutan to raid a Bhutanese national park in search of infected caterpillars.
Paul Cannon, of the intergovernmental agency CABI Bioscience, says that the rate that the caterpillars are being dug up is damaging the habitat and is unsustainable. And if, as seems likely, the area is destroyed to the point where caterpillars can no longer live there local people will lose their only source of income.
The Bhutanese government's efforts to prevent poaching have proved ineffective. Cannon says the only way to take the pressure off the local habitat is to set up farms in villages to grow the fungus.