Commercial hybrid vegetable seed production involves the movement of pollen between two distinct groups of plants (parent lines) – a pollen donor and seed production lines. The aim of this study was to observe the distribution and behavior of honey bees (Apis mellifera) on hybrid radish (Raphanus sativus L.) crops in New Zealand. Honey bees were observed to have an even distribution across the parent lines, although individual bees largely maintained fidelity to the particular line on which they foraged. Of the bees observed on male-fertile flowers, 72% did not switch to the other line. When plants from the different lines were manipulated so that they appeared to be a single plant, 69.5% of honey bees remained constant to the line visited. To maximize the effectiveness of honey bees as pollinators of hybrid radish, techniques should focus on the better matching of lines or breeding of lines to reduce pollinator differentiation.
