Abstract

Honey bee populations have experienced alarming declines, often associated with the presence of pathogens such as deformed wing virus (DWV). In this context, pollen is essential for the health and survival of bees. The biodiversity of Chilean native plants offers a unique opportunity to find natural resources with antiviral properties. In this sense, the effect of diets based on pollen of different botanical compositions on the reduction of viral load, the increase in survival and immune response of bees inoculated with the DWV-A was evaluated. Phenolic profiles and antioxidant properties were also studied. The results indicated that in honey bees treated with native Eucryphia cordifolia pollen significantly reduced the DWV-A load from 1.0 × 1013 to 1.0 × 105 copy number per bee, meanwhile, that polyfloral and monofloral Rubus ulmifolius pollen reduced DVW-A load from 1.0 × 1013 to 1.0 × 106 copy number per bee. The highest survival rate (91%) corresponded to bees that consumed E. cordifolia pollen; however, there were no significant differences detected with other pollen sources. Pollen diets modulated the expression of four immune-related genes, reducing Cactus expression while up-regulating Dorsal, Relish, and Dicer-like. Native E. cordifolia pollen showed high concentrations of gallic acid, vanillic acid, 3,4-dimethoxybenzyl, vanillin, chlorogenic acid, caffeic acid, quercetin, and kaempferol. Principal component analysis (PCA) revealed a separation between pollens according to their botanical composition, with greater distinction between non-native polyfloral and monofloral pollen of R. ulmifolius compared to native monofloral pollen of E. cordifolia. These findings highlight the antiviral value of pollens. © 2025 International Bee Research Association.