Xuefeng Cordyceps: insights into species diversity, life cycle and host association

Cordyceps (= Cordyceps sensu lato) fungi are rather well known as entomopathogens and also for their medicinal importance in curing many diseases. Many cordyceps species with widespread distribution throughout China have been recorded earlier. However, their taxonomy, hosts, life cycles and the plants on which the host insects reside in are poorly understood, and have sometimes led to confusion in the proper identification of the species. In this study, Xuefeng Cordyceps collected from Xuefeng Mountain, Hunan, China are identified and an assessment of their life cycles, proper hosts and plants they are associated with is made through morphological and DNA sequence-based analyses. Morphological characterization reveals that Ophiocordyceps xuefengensis from this region as commonly accepted by mycologists and local people. Species collected also include Beauveria bassiana (sexual and asexual), Metacordyceps taii (syn. of Metarhizium guizhouense), Ophiocordyceps macroacicularis and Ophiocordyceps ramosissimum. Our result challenges previous taxonomic arrangement with regard to host identity. The hosts, previously mistaken for larvae of Endoclita nodus, are corrected herein as larvae of Endoclita davidi (Lepidoptera: Hepialidae). Ribosomal DNA sequence analyses based on the ITS regions also confirm that Clerodendrum cyrtophyllum (Lamiaceae) is the plant on which the host insects reside. Morphological illustrations, where appropriate, are given for the cordyceps species, hosts and plants. The infection mechanism and life cycle of the cordyceps are also outlined.