From Pollen to Pathogen Defense: How Pollen Chemical Quality Impacts Deformed Wing Virus Infection and Survival in...

Pollen constitutes the primary source of proteins, amino acids, lipids, sterols, vitamins, and minerals for honey bees. However, not all pollen types provide the same resources or have the same biological value. Its chemical composition changes according to botanical origin, geographic location, and environmental conditions. This variability can influence metabolism, the immune system, oxidative balance, and the ability to resist or tolerate infections. This article examines the available evidence on the relationship between pollen chemical quality and the dynamics of Deformed Wing Virus (DWV) infection in Apis mellifera. The analysis is approached from molecular, physiological, ecological, and seasonal perspectives. Current findings suggest that more diverse and higher-quality pollen diets are generally associated with greater colony survival and improved health status, although their effects on viral load are more heterogeneous and context-dependent. In some studies, pollen intake is linked to a reduction in DWV, whereas in others viral loads remain stable or even increase despite improvements in survival, physiological condition, or colony performance. These differences suggest that pollen may act not only by enhancing resistance to the virus but also by increasing tolerance to infection-associated damage. The potential role of pollen bioactive compounds, particularly flavonoids and phenolic acids, is also discussed. Nevertheless, evidence of direct antiviral action of these compounds in bees remains limited, as many proposed mechanisms derive from other organisms. This synthesis provides an integrative perspective on pollen nutrition and its relevance for colony resilience against viral infections.