Web-like cortina protecting the gills in Cortinarius
Mushrooms are a great food source for a host of animals, large and small. Not least amongst these predatory problems are the insects. There is a group of so-called mycetophilids (mushroom gourmets of the insect world) that seek out the fruitbodies and lay their eggs on the cap, gills or whatever. Within days the fruitbody in some mushrooms becomes a writhing mass of tiny white larvae with black heads. If there is only a few larvae then most mushrooms afficionados just throw them in the pan along with the mushrooms slices. Too many larvae, however, is 'off putting' for the more squeamish (count me in!).
Fungi have to defend themselves as best they can from predation. How to do this? There are many ways to discourage the insect horde - some physical - some chemical. The CORTINA is one such physical modification that has evolved for protection of the developing gills. The developing gills are the site of spore production and are lined with a nutrient rich hymenium. The gills need protection at an early stage but must be exposed at maturity so the spores can be effectively dispersed. You can see that the web-like cortina is very effective in barring the way of insects that have the intention of laying eggs on the gills. The delicate fibres will stretch as the cap expands and by the time the caps has expanded fully the cortinal threads will break and disintegrate and at best just appear as a stain on the stalk.
1. Think of several additional chemical and physical mechanisms that fungi employ to protect their fruitbodies.
2. Some fruitbodies don't seem to have any protective mechanisms to dissuade insects etc from consuming them. How do you explain their successful survival?
3. The inner veil found in Amanita is a membranous sheath that functions in a similar fashion to the cortina. Is this a better design or not? Explain!