Birds Mediate a Fungus-Mite Mutualism

Area of Science:

• Mycology
• Entomology
• Ecology

Background:

• Mutualisms between ophiostomatoid fungi and arthropods are common, with fungi aiding nutrition and arthropods providing dispersal.
• Protea tree inflorescences host a unique community of ophiostomatoid fungi, including Sporothrix species.
• Mites are known to feed on and vector these fungi, while beetles aid in their dispersal between Protea trees.

Purpose of the Study:

• To investigate the role of birds, specifically cape sugarbirds, in the movement of mites and fungal spores within the Protea-Sporothrix-mite system.
• To identify mite species associated with Protea inflorescences and cape sugarbirds that carry Sporothrix fungal spores.
• To determine if these mites can feed and reproduce on their associated fungal partners.

Main Methods:

• Collection of mites from Protea inflorescences and cape sugarbirds.
• Screening of collected mites for the presence of Sporothrix fungal spores.
• Laboratory testing of mite-fungal interactions, including feeding and reproduction assays.
• Observation of mite dispersal mechanisms, including phoresy (hitchhiking) on other mites.

Main Results:

• Two mite species were found to be abundant on both Protea inflorescences and cape sugarbirds, regularly carrying Sporothrix fungal spores.
• One mite species, a Glycyphagus sp., demonstrated the ability to feed and reproduce on its fungal associate.
• This Glycyphagus sp. utilized phoresy, attaching to a larger mite species (Proctolaelaps vandenbergi) for dispersal by birds to new inflorescences.

Conclusions:

• The study provides strong evidence for a novel mite-fungus mutualism involving Sporothrix fungi.
• New instances of mite-mite commensalisms were identified, with one mite species facilitating the dispersal of another.
• This research presents the first documented evidence of birds transporting mites carrying Sporothrix fungal spores, enabling colonization of new Protea trees.