A mechanistic model to predict transgenic seed contamination in bee-pollinated crops validated in an apple orchard

► We develop a mechanistic model for dispersal of transgenic pollen by honeybees. ► The model is applied to apple pollen and validated with field data. ► The model is used to compute predicted outcrossing levels in neighbouring orchards. ► The model is used to compute isolation distances for target outcrossing levels. ► We discuss relevance to insect-mediated outcrossing in other plants and geometries.