Re. Blueberry Pollination
 
    Just to add to Stan's comments about (highbush) blueberry pollination.
    Indeed native pollinators especially bumbles are much more effective as
    pollinator on a per bee basis than honeybees.  Here in the Fraser
    Valley, blueberry is a major crop and many of the producers on the
    northshore (close to the mountain slopes with bush and undisturbed
    vegetation) derive great benefit from the wild populations of
    bumblebees.  But, in the central and western parts of the valley, the
    abundance of these populations is believed much less.  Also, wild
    populations tend to fluctuate wildly from one year to the next,
    something larger growers can not rely on for securing proper
    pollination.
 
    In recognition of the effective blueberry pollination by bumblebees, it
    has now been explored to use commercially reared bumbles for this
    purpose.  I have cautioned growers not to have unrealistic expectations
    of using these very costly bumblebee units. (PS. Part of the enthusiasm
    stems from the phenomenal success of bumbles in greenhouse crop
    pollination).
 
    As Stan pointed out, bumblebees may be much more effective pollinators
    in blueberry (and cranberry) but the number of available pollinating
    insects in a commercial planting is an important consideration.
    Consider the fact that for every acre of mature highbush blueberry
    planting an estimated 5million flowers must be pollinated.  Most
    plantings are over 10 acres and in some cases, several hundred acres.
    Commercial bumblebee nests harbor between 100 and 150 individuals of
    which only a portion would be actively foraging at any one time.  It
    seems a pretty daunting task for such small number of insects to cover
    that many flowers effectively.
 
    Some recent field visits also revealed that the honeybee colonies were
    much more active under the same lousy spring conditions we have had
    compared to the bumblebees.  This was rather surprising since it has
    always been reported that bumblebees remain active foragers at lower
    temperatures than honeybees.  Please don't interpret all this as a
    popularity contest between honeybees versus bumblebees.  It is strictly
    a question how these two different insect species compare in a field
    setting.  Ultimately, the grower who pays for the pollination service
    must get maximum benefit from the insects he uses.   As prices stand
    today, a grower can rent three strong honeybee pollination units for one
    bumblebee nest.  I can not see that under the present price structure,
    bumblebees (or anyother non-Apis pollinator) are more cost effective
    than honeybees.
 
    I should point out that because of the serious impact parasitic mites
    have had on the honeybee population, bumblebees and other pollinating
    insects have become valuable, complementary pollinators to all growers.
    We therefore also encourage growers to preserve habitat near plantings
    to enhance the presence of wild bee populations.
 
    Paul van Westendorp                 [log in to unmask]
    Provincial Apiarist
    British Columbia