Efficiency of airborne pollen released by honeybee foraging on pollination in oilseed rape: a wind insect-assisted pollination

Efficacité du pollen atmosphérique largué par les abeilles butineuses dans la pollinisation du colza : une pollinisation anémophile assistée par un insecte

Jacqueline Pierre , Bernard Vaissière , Patrick Vallée , Michel Renard

Oilseed rape (Brassica napus L.) is an entomophilous crop. Its pollen is covered with sticky pollenkitt and not readily released from the anthers. We investigated the role of foraging honeybees in making this pollen airborne. To assess this, six cages were laid over male-fertile (MF) and male-sterile (MS) plants; at flowering, three cages received a honeybee colony while the others served as controls. On average, approximately 25% more pollen grains were deposited on sticky slides (covered with gauze) in cages with honeybees, compared to control cages. The fruit and seed set per not-empty pod of 5 MS plants bagged under gauze to avoid bee visits were 7 times and 3.4 times higher, respectively, in the cages with honeybees than in control cages without honeybees. These results demonstrate the role of bees in releasing airborne pollen, as well as the effectiveness of this insect-assisted wind pollination: at close range, honeybees participate to pollination without touching the female flowers.

Mots clés: Apis mellifera; airborne pollen; pollination; Brassica napus<br>---<br>Apis mellifera; pollen atmosphérique; pollinisation; Brassica napus

Domaines: Zoologie des invertébrés; Biodiversité; Ecologie, Environnement; Science des productions animales

Jacqueline Pierre, Bernard Vaissière, Patrick Vallée, Michel Renard. Efficiency of airborne pollen released by honeybee foraging on pollination in oilseed rape: a wind insect-assisted pollination. Apidologie, 2010, 41 (1), pp.109-115. ⟨10.1051/apido/2009056⟩. ⟨hal-00892063⟩