Sexual confusion is a technique of biocontrol and collective in Champagne, which allows to fight against grape worms.
The larvae of the "cluster moth" (a butterfly) perforate the buds and grapes, which leads to a drop in production but also to grey rot on the grapes.
To fight against these larvae, the wine growers of Champagne meet among themselves to install in the vineyard, pheromone diffusers, called "RAK". Ce sont des petites capsules que l'on accroche sur les fils de palissage.
There is strength in numbers!
"The energy deployed by the site coordinators to unite the winegrowers around this biocontrol technique is commended. One of the keys to success is the effectiveness of the technique, which has been monitored every year for over 20 years."
- La Champagne de Sophie Claeys -
For the sexual confusion to be optimal, the installation of the "RAK" in the vineyard must be collective.
The winegrowers participate all together in the "RAK" break for one day for a village. This allows to optimize the number of diffusers per hectare and consequently the cost. It is important to avoid an overconsumption of diffusers, all purchased diffusers must be installed, otherwise they will be lost.
Allows to protect grapes from the appetite of cochylis and eudemis caterpillars, dreaded grape berry moths. It uses the principles of mating disruption control to do so. This consists in diffusing a copy of the natural pheromone emitted by the female in the atmosphere to attract the males of the targeted species in order to disorient them and limit mating.
This results in less mating, fewer eggs and therefore less caterpillar damage.
This targeted biocontrol technique is harmless to beneficials, leaves no residue on the grapes and in the wine, and respects the environment.
The installation of the diffusers:
The application is done at the very beginning of the first flight. A single application is enough to protect the vines until the harvest.
The diffusers containing the pheromones must be distributed in such a way as to cover the block in a uniform manner.
The recommended density is 500 diffusers per hectare. The installation is done in line or in staggered rows, on the vine or on the wire, at a rate of one diffuser for 20 square meters.
It is recommended to double the number of diffusers on the edges of the plot and to create buffer zones of 20 or 30 meters on the neighboring plots, with an identical installation of diffusers, in order to prevent females fertilized outside the zone under confusion from coming inside to lay eggs.