Nectar- and pollen-collecting behaviour of honeybees on canola (Brassica campestris L. and Brassica napus L.)
N. A. Mohr And S. C. Jay
The nectar- and pollen-collecting behaviour of honeybees was observed on two species of canola, Brassica campestris L. and B. napus L. Honeybees collected nectar from both species. Pollen was usually collected incidently while the bees foraged for nectar, but in one experiment, 48% of the honeybees actively collected canola pollen from B. napus. Honeybees foraging on B. campestris were observed to 'cross-over' 34-81% of the stigmas compared to 24-53% on B. napus. The lower percentage of B. napus stigmas crossed may be due to the higher percentage of 'thieving' that occurs on the larger flowers of this species. Thieving on B. napus was 18-65%. Bees foraging on B. campestris spent 12.5-19.3 s/plant, visited 2.4-2.6 flowers/plant and spent 4.6-6.6 s/flower. Bees foraging on B. napus spent 13.3-17.0 s/plant, visited 1.9-2.6 flowers/plant and spent 6.1-7.0 s/flower.