Ascopolyporus sinensis on an insect-killing fungus

Ascopolyporus sinensis was described from the area around Pu'er in Yunnan province. The material occurred on the undersides of living dicot leaves and was associated with the insect-killing fungus Metacordyceps puerensis. The arrangement is more complex than a simple fungus–plant relationship: members of Ascopolyporus develop within systems that include insects, fungi parasitising those insects, and the leaf surface.

The authors described the stromata, perithecia, asci and spores, as well as the characters of colonies in culture. On PDA the isolate produced a pale purplish-pink pigment. Culture colour is a useful comparative character, but on its own it is not enough for identification. Sequences from several DNA regions and phylogenetic analysis indicated the distinctness of the material within the genus Ascopolyporus.

The name was registered in MycoBank under the number MB 863421, and authorship of the taxon is written as Z.Q. Wang & Y.B. Wang. The epithet sinensis refers to China. The publication supplies photographs of natural material and of cultures, a diagnosis and molecular data. Such a complete set matters, because small structures on the underside of a leaf are easily confused with other epiphyllous organisms.

Pigment in culture may prove useful in comparing isolates, but its presence depends on the medium, the temperature and the age of the colony. It is not evidence of medicinal or industrial properties. Before a chemical compound is assigned a function, it has to be isolated, identified and studied. In a taxonomic description, colour remains above all an observable character of culture.

Material from the surface of a living leaf should be documented without stripping away its context. A photograph of the whole leaf, the position of the colony and the condition of the tissues help to distinguish an epiphyllous organism from damage to the plant. The publication does not indicate that A. sinensis is pathogenic to the plant itself. That distinction guards against over-reading a single photograph.

The same article, published in MycoKeys 137 on pages 257–272, describes two further new species from Yunnan: Cordyceps anningensis and Hypocrella umbilicata. Three new taxa in one paper from a single province show well how poorly recognised the local diversity of insect-associated fungi remains.

The ecology of the species should not be reduced to the word "hyperparasite" on the basis of one description. Co-occurrence alone shows a close connection, but the exact flow of resources and the effect on Metacordyceps and on the insect require experiments. The discovery draws attention to layered interactions in humid subtropical forests. A single find may take in a plant host as a surface, an insect, its pathogen, and a further fungus whose presence had previously gone unrecognised.

What the paper establishes

Ascopolyporus sinensis was described from material collected beneath a living dicot leaf near Pu’er, Yunnan. It occurred with the entomopathogenic Metacordyceps puerensis on an insect; sequences came from culture KUNCC 11590, and phylogeny recovered an independent lineage. MycoBank: MB 863421. On PDA, colonies produced a pale purple-pink pigment, but this is a laboratory character, not evidence of medicinal value or field function. The key correction is that co-occurrence does not demonstrate hyperparasitism. The paper does not trace resource transfer, perform an infection experiment, or show that A. sinensis parasitises Metacordyceps, the insect or the plant. Limited material also cannot establish its wider range, abundance, host breadth or conservation status.