Fungus-insect ecology offers a great opportunity to study why so many species can coexist in nature (i.e. the biodiversity paradox).

The wood-decaying basidiomycete Ganoderma produces perennial fruitbodies that provide food and habitat for three endemic beetles in a kauri-dominated forest, New Zealand. The beetles used a minute percentage of spores discharged and were therefore not food-limited. Competition was pervasive in the beetle community, as the larvae ranged over a restricted area on the hymenial surface and were likely to be space-limited. Modelling showed coexistence might occur as inferior competitors evade competition via different colonization strategies across fruitbodies.

The oyster mushroom Pleurotus fosters several broad functional groups of insects in an oak-pine mixed forest in Florida, USA. Experimental manipulation of patch isolation crossed with predator exclusion showed that when predators were absent, there was a unimodal relationship between isolation and local insect diversity, and when predators were allowed to colonize, there was a flat relationship. Competition-predation trade-offs were indicated by a few subsets of species, but a largely heterogeneous group of insects obscured the treatment effects on local diversity.

Altogether, these studies illustrate that spatial niches dictate much about species diversity of fruitbody-based insect communities.