Indirect Bee Vectoring in a Non-Entomophilous Crop: A Proof-of-Concept

Source abstract

Bee-mediated biocontrol (apivectoring) uses foraging bees to disseminate biological control agents within crop systems. Although this approach has been successfully applied in several entomophilous crops, its feasibility in non-entomophilous systems remains poorly documented. We evaluated an indirect apivectoring strategy in which bees foraging on interplanted strawberries (Fragaria × ananassa) acquired and transported viable propagules of Trichoderma asperellum from a dispenser to support the biological control of gray mold Botrytis cinerea in adjacent greenhouse roses (Rosa hybrida). A 3D-printed PLA dispenser was attached to a Langstroth hive containing Apis mellifera carnica and deployed in a rose greenhouse in Cotopaxi, Ecuador. Under laboratory conditions, T. asperellum inhibited the mycelial growth of B. cinerea by 61.7% and maintained a viability of 2.31 × 10⁴ CFU/g. In the greenhouse, foraging bees carried 590.6 ± 244.3 CFU per individual. Disease severity was 26.8% lower in the apivectoring treatment than in the control, while strawberry fruit weight increased by 30%. Farmer perception surveys identified the perceived potential to reduce fungicide use and provide additional pollination services, while also highlighting operational constraints related to hive management and technical training. These findings provide initial evidence supporting the feasibility of indirect apivectoring in a non-entomophilous crop, although further studies are needed to confirm fungal deposition on rose tissues.