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

[bmoisset at aol.com]

We knew we were losing pollinators more than 70 years ago and didn't care. Let honey bees take the slack. See this excerpt from the USDA document prepared by the Division of Bee Culture in 1946. https://archive.org/stream/deperi00unit/deperi00unit_djvu.txt


"Wherever a proper balance exists between plants and pollinating insects, both flourish. Agricultural development, however, has seriously interfered with this balance. It has demanded the growing of certain plants in enormous acreages and has unwittingly destroyed native pollinating insects as well as their nesting places. As a result the burden of pollination has been increased to such an extent that wild bees are no longer adequate or dependable, particularly where agriculture is highly developed. In many places the depletion of wild pollinators is so acute that honeybees have to be brought in especially for pollination, and so in practically all agricultural areas honeybees are now the most numerous of the flower-visiting insects."


Beatriz Moisset



-----Original Message-----
From: Clement Kent <clementfkent at gmail.com>
To: pollinator <pollinator at lists.sonic.net>
Sent: Mon, Nov 9, 2015 4:51 pm
Subject: [Pollinator] re Peter Bernhardt's question about cranberry and blueberry pollinators




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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