A disease called brown rot, which is caused by a fungus, costs the Australian cherry industry $150 million per year. To combat the disease, University of Adelaide researchers are trying a method called “entomovectoring,” which uses bees to deliver spores of a parasitic fungus to prevent the fungus that causes the brown rot from colonizing the flower.

“Instead of spraying fungicide, we’re using bees to deliver a biological control agent right to the flowers where it is needed,” said Dr. Katja Hogendoorn, a postdoctoral research associate with the University’s School of Agriculture, Food and Wine.

This is a new technique for Australia and a world first for cherry orchards, with potential application in many horticultural industries. It was recently demonstrated publicly for the first time at a field day hosted by Cherry Growers of South Australia and researchers at Lennane Orchards.

Every morning, the cherry growers sprinkle the fungus spores into specially designed dispensers that have been fitted in front of the bee hives. The bees then pick up the spores between their body hairs and bring them to the flowers.

“The ‘flying doctors’ technology is used successfully in Europe to control strawberry grey mould, but it’s the first time for Australia and the first time in cherry orchards anywhere,” Dr. Hogendoorn said.

The following video shows the system in use in Belgium:

The use of bees has many environmental and economic benefits compared to spraying fungicide.

“The bees deliver control on target, every day,” said Dr. Hogendoorn. “There is no spray drift or run-off into the environment, less use of heavy equipment, water, labor and fuel.”

The technique will also have the additional benefit of building up the honey bee industry and the number of managed hives, and it will help prepare Australia for the possible incursion of the Varroa mite, which is causing great damage to bee and horticultural industries around the world.

With increasing availability of suitable biological control agents, future application of this entomovectoring technology is expected to become available for disease control in almonds, grapes, strawberry, raspberry, apple, pear, and stone fruit.