Informant38

Question

A small toadstool that glows brightly at night is growing on a rotting log in my garden in south-east Queensland. What is the evolutionary advantage of such a characteristic? Does it attract things which it eats, or does it repel things which would eat it?

Thubten Gyatso , Eudlo, Queensland

Answers

Fungi glow not to attract things which they eat but to attract things which eat them. Many fungi benefit from animal dispersion. Truffles, for example, emit a strong aroma that attracts animals, which then eat the subterranean fungus. The spores pass through the gut and are not only dispersed but also provided with nutrients.
Virtually all members of the fungal family Phallales (stinkhorn fungi) give off an unpleasant odour redolent of rotting meat or sewage, which attracts beetles or flies. These disperse the spores, either when they pass through the gut or when they become attached to the insects' head or thorax. Similar dispersal mechanisms are common among flowering plants.
Phosphorescent fungi attract night-flying insects, such as moths, which perform the same role. It is quite common to find the fruiting bodies of such fungi moth-eaten and full of larvae, by which time the glow is reduced to that of the palest moonlight.
Michael Mcbain , Australian Fungal Mapping Project Monash University