Cordyceps is a genus of ascomycete fungi (sac fungi) that includes about 400 species.  All Cordyceps species are endoparasitoids, parasitic mainly on insects and other arthropods (they are thus entomopathogenic fungi); a few are parasitic on other fungi. 


Cordyceps Clavicipitales beginning its growth from an ant. image: Erich G. Vallery, USDA Forest Service/wikipedia

Until recently, the best known species of the genus was Cordyceps sinensis, first recorded as yartsa gunbu in Tibet in the 15th century and known as yarsha gumba in Nepali and "caterpillar fungus" in English. 

In 2007, nuclear DNA sampling revealed this species to be unrelated to most of the rest of the genus' members; as a result it was renamed Ophiocordyceps sinensis and placed in a new family, the Ophiocordycipitaceae.

Origin of the name Cordyceps

The generic name Cordyceps is derived from the Latin words cord, meaning "club", and ceps, meaning "head". 

A species of Cordyceps growing from a moth. more images: Andreas Kay/flickr

How it behaves or invades

When a Cordyceps fungus attacks a host, the mycelium invades and eventually replaces the host tissue, while the elongated fruit body (ascocarp) may be cylindrical, branched, or of complex shape. 

The ascocarp bears many small, flask-shaped perithecia containing asci. These, in turn, contain thread-like ascospores, which usually break into fragments and are presumably infective. 

Some can control the behaviour of the host

Some current and former Cordyceps species are able to affect the behaviour of their insect host: Ophiocordyceps unilateralis (formerly Cordyceps unilateralis) causes ants to climb a plant and attach there before they die. 

David Attenborough describes the behaviour and importance of Cordyceps in forests. video: BBC/

This ensures the parasite's environment is at an optimal temperature and humidity, and that maximal distribution of the spores from the fruit body that sprouts out of the dead insect is achieved. 

Marks have been found on fossilised leaves that suggest this ability to modify the host's behaviour evolved more than 48 million years ago.


Cordyceps species are particularly abundant and diverse in humid temperate and tropical forests.

The genus has a worldwide distribution and most of the approximately 400 species have been described from Asia (notably Nepal, China, Japan, Bhutan, Korea, Vietnam and Thailand). 

Other potential uses

Some Cordyceps species are sources of biochemicals with interesting biological and pharmacological properties, like cordycepin; the anamorph of Cordyceps subsessilis (Tolypocladium inflatum) was the source of ciclosporin—a drug helpful in human organ transplants, as it suppresses the immune system (immunosuppressive drug).


A cordycep fruiting body growing from within a tarantula. image: wikipedia Ian Suzuki