Tropical agriculture is under constant parasite and pest pressure, and transition toward sustainable food production involves improving natural regulation, so as to lessen dependence on synthetic control inputs. Parasitoids are major agents of biological control and could be attracted and locally recruited by habitat manipulation (conservation biological control). This approach, while scalable worldwide, is still in little use in Guadeloupe and in the broader Caribbean region.

We aim to produce innovative cucumber systems, integrating flowering plants to enhance natural parasitoid populations, so as to increase pest regulation. We focused on the main pest in Guadeloupe, Diaphania sp. This study includes 4 steps:

1) ex-ante assessment of farmers' willingness in implementing conservation biological control in cucumber cropping systems. 63% of survey farmers were interested in flower strips, though only 27% reported having the capacity to implement them. The study highlighted that adoption is constrained by increase in workload and the main lever is the access to training. Inner characteristics of service plants are also important in adoption, with farmers preferring plants easier to manage.

2) evaluation of indigenous plant species for their ability to create favourable habitats for parasitoids. 6 plant species were tested for parasitoid attraction. Preliminary results show high parasitoid preference for Asteraceae species Bidens pilosa and Cosmos sulphureus.

3) experimental analysis of agroecological cucumber systems integrating flowering plants with evaluation of pest damage, parasitoid-pest interactions, and yield. First results showed an increase of parasitoids over time in flower strips and field, with highest number of parasitoids in the flower strips. Diaphania sp. egg rearing showed a parasitism level > 97% and the emergence of Trichogrammatidae.

4) in-situ on farm evaluation of innovative cucumber pest management by comparing conventional plots vs. flowering plants plots. Set up this summer.

We will discuss farmers' preferences and how the evaluation translated as an experiment (1). We will report about selected species and how they meet farmers' expectations and agronomics traits (2). Finally, we will evaluate preliminary performance of the innovative cropping system (3).