Fungi fake flowers to fool bees

Fungal fraud found in South America - 8th March 2021

Scientists have caught a South American fungus engaging in an elaborate floral fraud. The fungus Fusarium xyrophilum sprouts fake flowers that are dead ringers for the canary yellow blooms of the grasses it infects in an effort to trick insects into spreading its spores.

The fungus apes the flowers of the Xyris plant found in the savannas of Guyana. The grasses' mechanism for producing real flowers is then sabotaged, leaving the fungal imposters as the only option for pollinating insects.

The bogus blooms' imitations go beyond mere physical resemblance, with its faux petals reflecting the ultraviolet light bees use to hone in on nectar-rich flowers. It also targets the olfactory senses by emitting a chemical aroma known to entice hungry insects.

The disguise is so effective that many insects fall for the fungus's wiles. Bamboozled bees anticipating a meal of nectar and pollen are instead met with a face full of fungal spores which hitch a free ride to the next unsuspecting host.

Fungi have been discovered deceiving insects into aiding their reproduction before. Monilinia fungi transform the leaves of blueberries into ultraviolet reflecting pseudo flowers that give off a fragrant odour and secrete sugar. The hoax proves irresistible to insect pollinators that go on to inadvertently disseminate the fungi's spores.

So while fungal subterfuge is nothing new, Fusarium xyrophilum's counterfeit flowers are by far the most sophisticated form of fungal mimicry yet discovered.