The midge Drosophila suzukii is spreading more and more in French orchards, producers are warning. This small insect from Asia colonizes fruits and its effect is devastating.

This is the fear of cherry lovers when summer comes: the worm that invades and colonizes the fruit to the point of making the consumer doubt when it comes to biting into this tasty little red fruit. In order not to spoil the pleasure of the tasting, there were until then several means.

The first is to treat the tree if it comes from a wild orchard, the second is simply to buy fruit from a greengrocer, the phytosanitary treatments of the producers guaranteeing a very limited risk of falling on a wormy fruit. The third is to monitor the appearance of the fruit, a small yellow hole on the surface to detect egg laying by a cherry fly.

Alas, a new insect has appeared and is ravaging French crops. From Corsica, Drosophila suzukii, coming from Japan, went up in the South-East before being reported in the Rhone basin, in Ile de France or in Alsace. It is now almost everywhere in France. The main cherry-producing basins, in Ardèche, in Vaucluse or in Drôme for example, are now invaded by them.

This tiny Asian fly wreaks havoc by colonizing barely ripe fruit to lay its tiny eggs. The larvae then develop in the heart of the fruit and devour them from the inside. The cherry then becomes soft and watery, becoming unfit for consumption, eventually falling from the tree. The harvest is quickly devastated and the signs to spot a colonized cherry are extremely reduced, alert the producers who have sounded the alarm bell. “When the suzukii attacks an orchard, all the cherry production is inedible: it gives a vinegar taste and the cherry is finished…”, notes an arborist from the Rhône, Alain Coquard interviewed by France 3.

French producers now say they are powerless to fight this invasion, especially since the banning of a pesticide in 2016 due to too high a concentration of the product on the fruit and then of a molecule, Phosmet, by the European Food Safety Authority (EFSA). The body justified its decision in 2022 by “a high acute and chronic risk for consumers”.

Deprived of this controversial chemical means, producers are reduced to installing expensive and not always easy to install nets or using products they deem less effective. As these flies reproduce at a high rate, particularly in hot and humid weather, some are warning consumers. “From mid-June, we will no longer be able to pick cherries,” said Florian Minodier, Ardèche arborist interviewed by AFP at the start of the year. Unless the weather is favorable, only the earliest fruits such as Burlat variety cherries could be spared. If you like cherries, it is better not to hang around to taste them…