An Italian team has been dispatched to the Sochi forests to combat the chestnut walnut pest, the chestnut nutcracker, which has threatened the survival of chestnut trees in the national park. The team has introduced 6,000 torimus flies, a predator of the nutcracker, in an attempt to control the pest. This biological control method is adopted after the ban on chemical methods in the reserves. The flies have shown effective results in other countries, with a 70% reduction of pests in Italy and up to 90% in Slovenia.