Position paper. Ergot (Claviceps purpurea) - An aposematic fungus

Predators learn to associate conspicuous signals, such as bright colors, with unpalatability or danger. This defensive strategy is termed Aposematism. We propose that the very poisonous purple-black sclerotia of the infamous fungus Claviceps purpurea (ergot) and many other Claviceps species are aposematic. Very toxic fungal sclerotia are associated with conspicuous colors (black, yellow, purple, reddish, brown, violet, white and their combinations) and severely harm herbivores that consume the infected plants, thus meeting the criteria for aposematism. Fungi, that only moderately reduce the reproductive capacity of their hosts can protect the host plants from herbivory and weaken the evolutionary tendency of their hosts to evolve better resistance to infection.