Sebastian, cell walls of fungi are made of chitine, the same component of insect exoeskeleton. For many reasons fungi need to be able to unconstruct cell wall. So many fungi have enzimes that decompose chitine called chitinases. Aditionally, saprofitic fungy, as Pleurotus, have a full set of decomposing enzimes. So it is very posible that the fungus is indeed breaking down the insect.

Thanks for the answer. The finding was impressive, because it occured on the fruiting  body and I expected that this part of the fungus does not need to break down organic material, thus is not able to. But your explanations suggest the opposite. I suppose, the functional units of fungi are not that differentiated than for example that of plants?

exactly, hyphae, even if their are in the fruitbody, remain very undifferentiated and still have a lot of the capabilities of mycelia.

Dear Sebastian,

Your observation is impressive indeed, particularly because it concerns not substrate hyphae but a fruiting body.

Many Pleurotus species (and P. eryngii among them) are known to be nematophagous (see some papers in attachment). Trapping nematodes allows fungi to get an additional nitrogen source which is scarce in wood. This means that they produce a range of proteases (pleureryn was recently found in P. eryngii - http://www.ncbi.nlm.nih.gov/pubmed/11726212) which can help to digest an insect too. P. eryngii isn`t a wood-decay mushroom but if not in culture it is a herbaceous plant pathogen and can suffer a lack of nitrogen too.

Best regards,

Elena

Many thanks for your detailed answer. Fungi as predators! Very interesting.

P. eryngii affects Eryngium campestre which for example grows on nutrient-poor calcareous grassland. So it is indeed useful to be able to digest dead insects on the fruiting body to obtain scarce nitrogen.

Fungi are important redistirbutors of biomass in ecosystems. They are able to predate on arthropods and then exchange acquired nutrients with trees, they do can forage on nutritionally rich pollen to decompose nutritionally scarce litter and they rearrange nutritionally scarce habitats creating nutritional niches for wood-eaters. Apart from nitrogen, other nutrients play also important role in these relations. See the works posted below.

Best!

Michał Filipiak

http://www.nature.com/nature/journal/v410/n6829/full/410651b0.html

http://www.sciencedirect.com/science/article/pii/S0953756208607200

http://www.nrcresearchpress.com/doi/abs/10.1139/b82-199#.WCtAT_nhCiw

http://www.mdpi.com/2075-4450/7/2/13

http://onlinelibrary.wiley.com/doi/10.1111/phen.12168/full

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