behaviour, not honey bee behaviour,” she explains. A bumble bee can effectively pollinate 6.5 blueberry flowers in the time it takes a nectar-foraging honey bee to pollinate one, and it takes four visits by a honey bee to deposit the same amount of pollen that a bumble bee deposits in a single visit. Unfortunately, there aren’t enough
bumble bees to do the job, with the amount of blueberry acreage there is now in the Fraser Valley. You can easily have much more than four to six times the number of honey bees in a field as you have bumble bees, so importing honey bees for pollination in large-scale, conventional agriculture is essential, she notes.
Bumble bee colonies are not nearly as large as those of honey bees, either.
Although there are eight or 10 species of bumble bees in the Lower Mainland, only three or four bumble bee species have been found active in blueberry fields, Elle reports from the first year of her study.
Growers should consider their presence as insurance during pollination, she feels. They also forage when honey bees won’t because the weather is too cold or wet.
To that end, Elle recommends that the wild bumble bee’s needs should either be encouraged or provided by growers to keep that insurance policy alive and active.
Managing habitat is most important, so ensure there are flowers available nearby when the blueberry fields are no longer in bloom—or before they bloom. Encouraging wildflower strips near berry fields is one way to attract more wild bees, or planting species to lengthen the season you’re providing feed for bees, with such early bloomers as pieris japonica, and later wild plants such as fireweed, asters and goldenrod, or non-natives such as lavender and mint family plants, she suggests.
“You can’t pick the farm up and move it, but if it’s near ditches, parks or natural areas, it may make quite a difference to your pollination success,” she commented. Greater plant diversity results in greater bee species diversity and better pollination—so a higher yield. “It could take three years, but they (wildflower strips) should produce
Hand pollination of blueberry blooms. The shape of some varieties is suited better to one bee species than another.
better pollination,” Elle advises. Wild bee declines are linked not only to habitat loss but also to pesticide use, so care is needed when applying sprays that there is none applied during bloom or when pollinators are present, and no overspray during the rest of the
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season, so you don’t impact pollinators in nearby habitat. Bees are the most effective pollinators because they aren’t just feeding themselves when they visit flowers; they’re collecting pollen and nectar to feed to their offspring, Elle explains.
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