Fecha de publicación: -- Fuente: PubMed "bee pollen" Environ Pollut. 2026 Oct 15;411(Pt A):129357. doi: 10.1016/j.envpol.2026.129357. Online ahead of print.ABSTRACTPesticide exposure is a central component of pollinator risk assessment. Yet, how field application rates translate into actual bee exposure remains poorly understood. We traced translocation of the fungicide tebuconazole from the spray tank to flowers, pollen and nectar, up to the body of adults and larval food provisions of the solitary bee Osmia cornuta foraging on oilseed rape and apple. Tebuconazole levels measured on the day of application and the day after were notably higher than previously published records. We found that, relative to the spray tank concentration (100%), residues decreased consistently across bee-relevant matrices in the following order: flowers (16-20%) > pollen (2-14%) > provisions (1.5-3.6%) > nectar (0.12-0.13%) ≥ bees (0.02-0.17%). Comparisons of our results with RUD (Residue per Unit Dose) distributions revealed crop- and matrix-specific deviations in residue levels. We also investigated fungicide degradation rates on flowers and in larval provisions within the bee nest of four fungicides with contrasting modes of action (tebuconazole, boscalid, pyraclostrobin and captan). Residues dissipated rapidly on flowers but remained largely stable for up to 12 days in stored pollen-nectar provisions. These results show that food provisions act as fungicide reservoirs, with larvae experiencing full exposure levels well after provisions are built. Consequently, exposure levels calculated from on-flower pollen-nectar measurements may grossly underestimate actual larval exposure. We combined food consumption estimates from the literature with our residue measurements to estimate fungicide intake in O. cornuta adults and larvae.PMID:42880572 | DOI:10.1016/j.envpol.2026.129357