Gray mold (or, grey mould as our European friends spell it) is a bane to strawberry farmers. It infects the fruit of strawberry plants and turns it into an inedible mushy mass of spore-filled yuck soon after the fruit is picked, packaged, and sent to market. The gray mycellium consume the berries, spread to other nearby areas, and generally cause much consternation to those agriculturists who make a living by providing fruit lovers with the strawberries they crave.
In the UK, a novel approach is being pioneered by growers to prevent gray mold from ruining their crops. They are using a benign mold species to innoculate their crops so that the pathogenic strains cannot be established. Here is the skinny on how it works:
Bumblebee hives are situated so that the bees are forced to enter an exit through a tray of harmless fungus spores. As they do so, the fuzzy insects pick up the inoculant. They then carry those harmless spores around and deposit them on strawberry flowers. The presence of the harmless spores prevents the gray mold spores from finding purchase on the surface of the fruits. Consequently, the bad fungus is unable to do damage after harvest because of the fact that the real estate they would have normally occupied is unavailable.
The system being used has been developed by BioBest, a Belgian company. More about strawberry farmers battling gray mold with bumblebees can be read here: Farmers turn to bumblebees to save strawberry crops