[Pollinator] re Peter Bernhardt's question about cranberry and blueberry pollinators

[Clement Kent]

Cranberries: Broussard et al 2011 (
http://hortsci.ashspublications.org/content/46/6/885.short) found honeybees
and bumblebees in cultivated cranberries in a 2:1 ratio but pollen
collection was in a 1:2 ratio. In other words, if pollen collected predicts
pollinator impact, bumblebees and honeybees were about even in this study.

Blueberries: Buzz pollination is important in highbush blueberries, and
bumblebees are therefore more effective than honeybees. "Bumble bees and
other species of wild bees are the most effective pollinators of
blueberry." (pollinator.ca,
http://www.pollinator.ca/bestpractices/blueberries.html, and references
therein). Lowbush blueberries were predominantly pollinated by bumblebees
and other native bees until introductions of pesticide spraying for spruce
budworm in Eastern Canada reduced their numbers greatly. The attendant crop
losses showed they were important to the crop (Kevan 1975 et seq). In very
large commercial lowbush blueberry fields which have little alternative
forage, honeybees are indeed imported to maintain yields, but local
agricultural agents note that this will not be required if farmers maintain
forage strips of wildflowers around blueberry fields.

So yep, honeybees are often used with both crops, but they aren't as good
as bumblebees at it. Honeybees are used where excessive pesticide and
herbicide used has made native pollinators less abundant.

Clement Kent
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