Hymenostilbe nutans

Hymenostilbe nutans

Saturday, August 6, 2011

Insect or Plant?

As a follow up to the vegetarian angle I was reminded by Zoe that in Chinese Cordyceps sinensis translates as 'winter insect, summer plant'. The Chinese is a translation of the Tibetan/Bhutanese/Nepali name – yarza guenbob. A common English translation is: 'winter worm, summer grass'. Zoe asked me if this is what the life-cycle involved. The simple answer is yes and no. With this beastie we are dealing with two life cycles. The insect and the fungus. An uninfected insect will go from caterpillar to pupa to adult moth. That life-cycle goes full-circle when the female moth lays her eggs by dropping them over the alpine grasslands of the Himalayan Plateau.

When those eggs hatch out some will become infected with Cordyceps. The Cordyceps will grow inside by taking the nutrients the caterpillar was hoping to use to turn into a pupa and ultimately a moth. When the time to change comes the caterpillar has nothing left. It dies. And the Cordyceps finishes things off by 'eating' the rest of the caterpillar. All that is left of the caterpillar is the outer skin. The rest is fungus.

When the Himalayan mountain snows melt in April/May the fungus grows out from the dead caterpillar. From Mid May to late June yak herders in Tibet, Bhutan, Sikkim and Nepal can collect the Cordyceps as it grows out of the soil like a summer grass.