Boletes and the Bolete Eater: A Fungal Horror Story on Margaret River Trails

May 2025: The Eerie sight of the Bolete Eater

Boletellus obscurecoccineus (Rhubarb Bolete): Infected with Hypomycese

Bushwalking through the stunning Margaret River trails always holds the promise of discovering nature’s hidden treasures. This year, my hikes have been particularly fascinating, as I’ve encountered a remarkable variety of boletes—those stout, sponge-pored mushrooms—many of them infected with Hypomyces chrysospermus, also known as the bolete eater mould.

Boletellus obscurecoccineus (Rhubarb Bolete): Infected with Hypomycese

Hypomyces is a parasitic fungus that transforms the boletes, covering them in a white or yellowish crust, depending on its stage of development. It’s a surreal sight—beautiful yet slightly eerie. The infected mushrooms lose their characteristic sponge-like pores, becoming crusty and sometimes completely unrecognizable.

Unknown Bolete Species: Note the Hypomyces on the right.

What’s truly captivating is the diversity of boletes falling victim to this mould. From large, robust species to delicate, velvety ones, the variety this season has been astonishing. It’s a reminder of the complex interplay of fungi in the ecosystem—how even the seemingly mighty boletes can succumb to another fungal force.

For fungi enthusiasts, stumbling upon these transformations is thrilling. Observing nature’s cycles, where one organism thrives at the expense of another, gives insight into the hidden world beneath our feet. Margaret River’s bushland is a living laboratory, teeming with mysteries waiting to be explored.