Termite Ball Fungus

Athelia species are typically pale colored, drab, and morphologically simple. Even crust experts fail to feel much excitement for them. However, what they lack in morphological excitement, they make up for with their varied and interesting ecological roles. Athelia termitophila is no exception! As its species name suggests, Athelia termitophila enters a unique symbiotic association with termites. The fungus produces small spherical structures called sclerotia that mimic its host's eggs in both size and chemical profile, tricking the termites into tending the fungal structures as if they were their own eggs. What's the point of this trickery, you may wonder? The fungus benefits from increased dispersion from the termites transporting its sclerotia, and the termites too seem to benefit with egg survival increasing in the presence of sclerotia. First documented in 2000, it wasn't until 2020 that the association between termite balls and the Athelia teleomorph was established (Matsuura et al. 2000, Maekawa et al. 2020). 

Upon encountering an Athelia species, you should explore the substrate for termite balls in case it is Athelia termitophila. Truthfully though, one's chances of finding sclerotia in the wild may be low — besides being impossible to know which Athelia species you are working with in the field, the sclerotia and basidiomata tend to grow at different temperatures, and they are infrequently found together (Maekawa et al. 2020). But it doesn't hurt to look, and how extraordinary would it be to find termites tending a pile of termite balls!

Microscopy is required to identify a species to Athelia and to distinguish Athelia termitophila from other Athelia species. Athelia decipiens is similar but does not produce clamp connections (completely simple-septate). Athelia nivea and Athelia salicum resemble A. termitophila in basidial and hyphal features but produce larger basidiospores.

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