•    In a first phase, the volatile molecules emitted by both plants and fruits will be analysed to identify those with the strongest repellent effect.

•    Other plants that release volatile compounds with the same effect will also be sought to intersperse them among the affected crops.

Researchers from the Institute of Agriculture and Food Research and Technology (IRTA), the Centre for Research in Agricultural Genomics (CRAG), and the University of Salamanca (USAL) are launching the "GreenSuzukii: biological control of Drosophila suzukii using plants as volatile biofactories" project to find a new solution to combat the spotted-wing fly (Drosophila suzukii) plague based on biological control. This is a fly of Japanese origin that affects red fruit crops such as cherries, strawberries, raspberries or blueberries. Females inject eggs into the interior of fruits and, when the larvae emerge, they destroy much of the fruit to the point of causing devastating effects. So far, several strategies have been tried without success, such as the use of broad-spectrum insecticides, which go against European environmental policies and generate resistance, and covering the plantations with physical barriers. Now, with the GreenSuzukii project, the research teams want to identify the volatile and aromatic molecules of the same plants and red fruits that are victims of the plague to find those with the most potential repellent for the fly. On the other hand, they will look for other plants that also emit repellent molecules for the insect and intersperse them between the crops. With all this, "the objective is to implement this new technology in a pest management program that integrates the use of biological control and natural pollinators," say Jordi Riudavets and Judit Arnó, researchers from the IRTA's Sustainable Plant Protection program and coordinators of the project.

In the first phase, IRTA will evaluate the effect of the volatile organic molecules from strawberries, raspberries and blueberries on the fly in its experimental greenhouse sites. At the same time, it will study whether this system is compatible with other insects that act as natural enemies of pests and pollinators. In parallel, CRAG will study the genetic mechanisms that make plants emit more or fewer molecules and in which parts of the plant they are generated and accumulated.

"We have many previous studies on the aromatic and volatile molecules of strawberries and raspberries, so they will serve as a model to see if they act as a repellent to the fly and then we will study it in other red fruit crops," explains Amparo Monfort, IRTA researcher at CRAG and head of the Genetics and Genomics of Rosaceae group.

Finally, scientists from the Excellence Unit for Agricultural Production and Environment 'AGRIENVIRONMENT' of the Institute for Agribiotechnology Research (CIALE) of the USAL will identify other plants that emit useful molecules for controlling the fruit fly and that can be planted interspersed among the affected crops. Researchers Óscar Lorenzo and Ricardo Costa from USAL explain that "the goal is to develop the most effective agronomic practices for growing and maintaining these plants and to study the times of the year when it would be appropriate to plant them according to the life cycle of the fly. One of the difficulties in dealing with this pest is that the fly has a very short life cycle, which makes it reproduce very quickly".

According to the experts, "we are still far from completely dispensing with pesticides, but thanks to projects like this, the use of pesticides could be reduced and nature could work with and for us. If we show that it is an effective technique, we will transfer it to farmers and the agri-food industry to apply it in real conditions and reduce the impact of this pest." Currently, the spotted-wing fruit fly is distributed throughout Europe and America, and it was first detected in the Peninsula in 2008 in Catalonia, spreading rapidly throughout the territory.

The "GreenSuzukii: Biological control of Drosophila suzukii using plants as biofactories of volatiles" project has received funding from the State Research Agency through the "Projects Oriented towards the Ecological Transition and the Digital Transition" call with Next Generation EU Funds and will be presented on the 1st and 2nd of February at the Fonseca Hostelry of the University of Salamanca.

About the funding of the project

Project TED2021-130898B-C32 funded by MCIN/AEI/10.13039/501100011033 and by the European Union NextGenerationEU/PRTR.