Mushroom Extracts for Bee Immunity

In the reported study, five of about ten tested polypore species reduced bee viruses. Mushroom extracts reduced harmful bee viruses broadly by about 90%, with larger reductions reported for some specific viruses. The bee treatment used 1% mushroom extract in sugar water, a form compatible with common beekeeper feeding practices. Honeybees were observed feeding on droplets from garden giant mushroom mycelium for 40 days in 1983. The proposed mechanism is immune upregulation in bees rather than a direct drug-like antiviral molecule. The article suggests bees may seek immune-supportive fungal compounds, not only sugars. Commercial sale of mushroom mycelium as bee feed faces regulatory obstacles because bees are treated as minor livestock and the substance is not listed as permitted bee food. A key hypothesis tested whether antiviral polypore mycelial extracts could reduce viruses harming bees.