[Pollinator] Fact Checking?

[Peter Bernhardt]

Dear Peter:

Mangos have tiny flowers as do all members of the Anacardiaceae.  It's a
matter of the bee's body hitting both targets (anthers AND stigma).
Small-bodied bees should be most effective as pollinators of flowers of
similar dimensions.  It does not matter if tiny flowers are compressed into
massive inflorescence.  Note how well small bees pollinated members of the
Asteraceae where bisexual florets are massed into the same cup of bracts
(involucrum).

There are three commercial species of coffee.  Most of what is grown
through the tropical americas is C. arabica.  It is self-compatible and,
self-pollinating.  The other two species may be different stories
especially if the ancestral, early-acting self-incompatibility is
retained.  Each coffee fruit makes only 2 seeds.  Technically, only 2
pollen grains need to reach the stigma.

Peter

On Mon, Nov 9, 2015 at 5:45 PM, Peter Kevan <pkevan at uoguelph.ca> wrote:

> Hello All:
>
> There are a number of publications on the pollination and pollinators of
> Vaccinium species (blueberries and cranberries).  I suggest they be
> consulted.  Yes, honeybees can be used and are used for commercial
> pollination of cranberries and blueberries but the scientific literature
> generally acknowledges that honeybees are inferior pollinators on both.  If
> the better, native pollinators are few as a result of production practices,
> then honeybees are a fallback even if inferior.
>
> There are again several papers on pollination in coffee, both robusta and
> arabica.  I suggest they be consulted.  Yes, Trigona spp. visit coffee
> flowers.  If readers consult Dave Roubik's FAO Technical Bulletin on
> pollination of tropical  crops, then one might be able to tot up 90
> species. The reasoning of bodies being too small is irrelevant and
> fallacious (think about mango inflorescences).
>
> There are recent papers on Vaccinium and Coffea pollination in the Journal
> of Pollination Ecology.  Their cited literature is useful.
>
> Peter
>
>
>
>
>
> ------------------------------
> *From: *"Peter Bernhardt" <bernhap2 at slu.edu>
> *To: *"Bee United" <beemonitoring at yahoogroups.com>, "Pollinator
> List-serv" <pollinator at lists.sonic.net>
> *Sent: *Saturday, November 7, 2015 12:14:16 PM
> *Subject: *[Pollinator] Fact Checking?
>
> Within the last week there two statements appeared regarding the the
> pollination of crops.  The comments of members working on bee-pollination
> of crops would be appreciated.
>
> 1) November 5, Saint Louis U.  A bee conservation lecture series was
> held.  One of the speakers was Gerald Hayes from Monsanto on the role of
> honeybees and our food supply.  Hayes insisted that our North American,
> cultivated, cranberries were pollinated by honeybees.  Is this correct?  I
> remember a seminar by Jim Cane emphasizing the importance of native
> megachilids for cranberry pollination.  The speaker also insisted that
> blueberries were pollinated primarily by honeybees in North America.
>
> 2) CJ Bradshaw and Paul Ehrlich released a coauthored by book from
> University of Chicago Press (my publisher) last month.  On page 58 the
> authors insist that Trigona (species not identified) pollinates 90 species
> of crop plants including coffee.  I know that most coffee marketed today is
> self-pollinating although it still yields sufficient nectar for introduced
> honeybees to make honey but what of the other 89 other crop species?  I am
> aware that Trigona pollinate avocados, macadamias and a few other fruit/nut
> trees but, generally speaking, their bodies are too small to contact both
> anthers and stigmas as they forage.
>
> Peter
>
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