samedi 20 décembre 2014

Parasite of the month

Ophiocordyceps sinensis


This fungus parasitizes the caterpillar of ghost moths (Thitarodes spp.) that live on the Tibetan Plateau and the Himalayas. It infects hosts during the summer, after caterpillars shed their protective coatings and move underground to hibernate. The fungus consumes the host during the hibernation in alpine meadows and produces a stalk-like fruiting body that emerges from the head of the caterpillar in the early spring.  The germination process leads to the death and mummification of the larvae. During this process, infected larvae tend to remain vertical to the soil surface with the heads up. This facilitates germination and dissemination of the spores by the fungus.

The fruiting body of this fungus is used as herbal remedy to cure several diseases, especially those related to lungs, kidneys, and erectile dysfunction. The oldest reference to its use in medicine dates from the 15th century. Overharvesting for these means has led to the rarefaction of the fungus. It is now classified as endangered species. Yet, the fungus is still being sold in Asia and its price can reach up to 65 700€ per kg - quite an expensive Christmas gift...