Sexual confusion is a viticultural practice that aims to protect the vineyards from insects without the need to spray insecticides. One of the pests that vineyards may suffer is the grape worm (eudemis and cocylis in French).
They are small worms that make tiny holes in the grape skin. Juice seeps out through the holes and cause the grape bunches to rot, potentially causing great damage to the harvest. You can fight the insects with poison but a less dangerous method is to use “sexual confusion”. For the grape worms to appear the male insects and the female insects have to meet and do what the need to do to make baby grape worms.
Since they don’t have Facebook what happens is that the females produce a pheromone that attracts the male. Some clever people at BASF (a chemicals company) invented a way to destroy the insect fun. They make small capsules filled with the female pheromone that the worried vigneron can place in the vineyard. The pheromone from the capsules overpower the females’ own perfume which leads to that the male insects can’t find the females, thus preventing the production of new grape worms (presumably the males cluster around the plastic capsules instead). This has become a popular way to fight the problem.
Today 3% (18,000 ha) of France’s vineyards are protected in this way – varying from an impressive 41% of all vineyards in Champagne to virtually no vineyards in the Cognac region.
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