Controling the pest Drosophila suzukii with the sterile insect technique: maturation and efficacy – SuzuKIISS.ME

Strawberry, raspberry and cherry farmers lack solutions to control the invasive pest Drosophila suzukii (DS). Here, we will maturate the Sterile Insect Technique (SIT) targeting DS. SIT has shown great efficacy to control many insects in foreign countries. It prevents reproduction by wild females through their mating with sterile males of the same species, which are mass-produced, sterilised and regularly released in large numbers. Females that mate with them produce non-viable eggs, hence reducing the population over generations. DS SIT will be deployed in semi-enclosed environments such as greenhouses and netted orchards.
Key initial technical elements have been reached, positioning DS SIT at a TRL of 4: the rearing process and pupae sterilization are mastered at a small-scale; a high-performance genetic line selected by the project leader greatly reduced female fertility when competing with wild males, in laboratory trials.
This project will mature the technology to TRL 7 thanks to: (1) scale-up and optimization of the operational steps (production capacity, handling, packaging, transport, adult sterilization); in order to (2) evaluate various parameters of efficacy in operational conditions; taking into account (3) the integration and consequences of DS SIT on both farming practices and the surrounding environment; and allowing to (4) propose organizational scenarios to implement DS SIT at the territorial level based on stakeholders’ engagements.

We will combine prototyping, field testing, in-situ monitoring, laboratory investigations and socio-economic studies. Laboratory-scale research will enable tweaking various operational levers to increase quality and effectiveness. By increasing the testing scale - from experimental greenhouses to operational contexts in commercial farms - will we identify practical challenges and impacts. A socio-economical approach will unveil how to deploy DS SIT for the protection of these three commodities.

Strawberry, raspberry and cherry farmers are the future users and core stakeholders. Crops grown under tunnels or protected by nets are the targets of this project; due to DS abundance, control in open field is not a current goal. This project is led by the ambition to create a commercial entity for DS SIT services (production, release, monitoring). The operational trials will allow assessing the benefits-costs in view of large-scale deployment, both for industry, users and stakeholders.

The SIT is an alternative to chemical insecticides. Due to a lack of sustainable solutions, current DS control mostly relies either on molecules subjected to temporary authorizations, or the costly manual sorting of infested fruit.
Successful SIT actions nest into Integrated Pest Management strategies (IPM). Mandatory changes on pests and diseases management will include the fine-scale monitoring of DS and the adaptation of sterile releases to field observations. Technical support to growers and education is hence mandatory.
The sustainability of the solution will rely on the active participation and regional coordination of users and stakeholders. To this effect, we will elaborate organizational scenarios of integrated strategies meeting their constraints.
SIT long-lasting adoption through stakeholders’ involvement, will have positive impacts for environment, health and society. The SIT participates to the agroecology transition and a renewed relationship between growers and pests.

Our transdisciplinary consortium has background in ecology, mathematics and socio-economy. All partners are involved in SIT pilot projects or in the pioneering of DS SIT and have worked together in the past. INRAE coordinates the project, closely with the economic partner CTIFL, with the common goal of developing a commercial solution. Due to their position in French agronomy R&D, partners are best placed to disseminate project results to different audiences including value chain actors.