Does in-hive pollen transfer by honey bees contribute to cross-pollination and seed set in hybrid cotton?G.M. Loper and G. DeGrandi-Hoffman
US Department ot Agriculture, Agricultural Research Service, Carl Hayden Bee Research Center, 2000 East Allen Road, Tucson, AZ 85719, USA
Abstract - Whether or not sufficient amounts of cotton pollen are transferred among nestmates in honey bee hives to influence cross-pollination and seed set in cotton was tested. Honey bees foraged on genetic cytoplasmic male sterile (CMS) cotton flowers in greater numbers than on male fertile (MF) flowers, and most of the foragers on MF flowers collected nectar rather than pollen. Pollen-free worker bees either pinned at the hive entrance or released in the hive obtained very little cotton pollen on their bodies from nestmate contacts, although all of them obtained large amounts of pollen from other plant species. Seed set on CMS plants did not decrease significantly with distance from MF plants in 1988 when foraging activity on CMS plants was high relative to that in 1989. In 1989 when there was less foraging activity on CMS flowers, seed set on CMS plants decreased significantly with distance from the MF row. These studies indicate that there were insufficient numbers of honey bees returning to their colonies with significant amounts of cotton pollen on their bodies to ensure effective transfer of cotton pollen among nestmates in the hive.
Key words: foraging behavior / pollen transfer / Gossypium / hybrid / pollination