Black Death for Xanthoria ?

Black Death for Xanthoria ?

Observation - Black Death for Xanthoria ?. Description: The lichen is Xanthoria parietina, but the focus here is not on the lichen, but its ill health, and what may be parasitising it.

The lichen is Xanthoria parietina, but the focus here is not on the lichen, but its ill health, and what may be parasitising it.