Samuri solution identified for destructive fruit bug

Swiss fruit farmers are turning to the Samuri wasp to preserve their crops from a destructive pest that has caused more than CHF3 million ($3 million) of damage this year.

Fruit harvests, particularly pears, have been devastated by the Marmorated Tree Bug, an unwanted import from Asia. Thurgau, the second largest cantonal pear producer, has had a quarter of the crop decimated in 2019.

The trail of destruction has also been witnessed in cantons Zurich, St Gallen, Aargau, Lucerne and Zug. The Swiss Fruit Association says the problem is twice as bad as in 2018. It also results in additional costs for sorting the fruit to determine which have been attacked by the bug.

The bugs sink their needle-sharp stylets into the fruit, creating blemishes and sour patches that make them unfit for supermarket shelves.

Farmers want to turn to another Asian export, the Samuri wasp, to tackle the problem in an ecologically-friendly way. The wasp is a natural predator for the bug and could help reduce numbers of the pest without having to resort to extra doses of pesticide.

The Fruit Association told Swiss public television SRF that it has applied for permission to release the wasps into Switzerland. According to studies, the same solution has been tried in other parts of the world.

In the meantime, the Swiss authorities have approved the use of certain insecticides against the Marmorated Tree Bug in the hope of holding the pest back until alternative solutions can be found.