**2. The life cycle of** *Cordyceps sinensis*

*Cordyceps sinensis* fungus begins off its wondrous life cycle with the combination of an underground caterpillar (insect)—mostly Lepidoptera larvae, which generally lives about 15 cm underground. One of the special factors, which affect the initial point to begin the life of *Cordyceps sinensis* and which enable its identification from other fungi, is the low temperature that is required for its life cycle. This particular temperature is believed to be below approximately 21°C [6]. The life of the caterpillar fungus which begins under these conditions carries out a slow growing procedure thereafter.

The underground caterpillars which survive by feeding on the underground roots start to shed off their skin in the later part of summer and autumn seasons. Therefore, their skin becomes more vulnerable to fungal spores. Fungal spores, which begin to interact with the chemicals on the skin of these caterpillars, release a fungal mycelium, which then starts infecting the caterpillar to its death. With its death, a formation of a stalk-like structure of the mushroom grows out of the upper part of the head of the dead caterpillar and that particular structure emerges above to the ground surface in the season of spring. The infected larvae after its

death become a rigid structure due to the production of the fungal sclerotia, which could pause the germination for a while to produce spores. Right after the end of the winter season, the formation of the mushroom body continues, and along with that, the perithecial stroma grows upward in order to emerge above the ground soil, thereby concluding its life cycle.
