Scientists are warning that the global hazelnut supply could be threatened by a stinkbug that has recently invaded Turkey. The brown marmorated stinkbug, native to north-east Asia, has been spreading across the world in shipping containers, breeding freely thanks to warmer temperatures and a lack of natural predators.
The stinkbug was seen in Turkey for the first time in 2017, after wreaking havoc in neighbouring Georgia. Since then, the insect has spread through at least eight Turkish cities, mostly across the Black Sea region, where about 70% of the world’s hazelnut supply originates.
If the stinkbug’s spread cannot be contained, about 30% of hazelnuts could be damaged, warned Prof Celal Tuncer from Ondokuz Mayıs University’s plant protection department. This corresponds to about a fifth of the world’s supply.
This dependence on Turkish hazelnuts has prompted the industry as well as scientists to call for rapid action against the stinkbug. At a conference in January, discussions focused on fighting the invasion through the dissemination of a natural enemy: the samurai wasp. The method of using pests’ natural enemies is known as biological control, and is considered an eco-friendly alternative to the use of insecticides.
One potential problem with this approach is that it usually requires more time than Turkey’s hazelnuts appear to have. Regulations require extensive research before releasing a biocontrol agent in order to ensure that it is not harmful to the local ecosystem.