One invasive species that began to appear in Europe over the last decade or so is the Halyomorpha halys, commonly known as the brown marmorated stink bug. Native to eastern Asia, the bug feeds on more than 170 plant species, including tree fruit, nuts, vegetables and field crops. It causes significant crop damage every year. To date, broad-spectrum insecticides have been the most common way of managing it. However, food safety and ecosystem health concerns have made finding more environmentally friendly and sustainable control measures imperative. A promising solution is the biological control of this agricultural pest using one of its natural enemies.
First samurai wasps found in Switzerland
Research conducted in the course of the EU-funded project BINGO has led to the discovery that Trissolcus japonicas, a natural enemy of H. halys, is already present in apple orchards in the Canton Ticino, in south-eastern Switzerland. This is the first time that T. japonicus, commonly known as the samurai wasp, was recovered from stink bug egg masses in Europe. A paper published in the Journal of Pest Science provides details on this discovery.
"It is difficult to say for certain how Trissolcus japonicus arrived in Switzerland – the 2mm big wasp was probably accidentally transported from its native range along with the pest," says co-author Dr. Tim Haye. "But whether Switzerland was the actual country of introduction or whether the wasp was introduced into the climatically highly-suitable northern Italy before spreading northwards remains unclear."