Healthy soil and sustainable growing

[Pete Vukovich <pvukovic1@yahoo.com>]

And its still illegal to import them into california, unless you have a license which shows they will only be kept indoors in a controlled environment. I looked into it a few years back,  the powers that be were worried that non-native bombus might out compete the native bombus's('s). So I dropped thinking about it, since I really didn't know how to attract a ground dweller - I did end up getting a nest of them at one point, but I think its because they had nowhere else to go.

If I can recommend a book 'bumblebee economics' (heinrich), I found it pretty interesting. If I remember right I read somewhere that bombus is about 4 times more effecient (in terms of pollen wieght) than honeybees at pollinating plants that both pollinate. Since they don't produce extra honey (only what the brood need for the season), I don't think many people have considered trying to encourage them as pollinators.

Thanks for the article, it reminds me I have to do some reading.....

--pete

--- On Tue, 1/4/11, Tradingpost <tradingpost@lobo.net> wrote:

From: Tradingpost <tradingpost@lobo.net>
Subject: [Livingontheland] Bees in freefall as study shows sharp US decline
To: livingontheland@lists.ibiblio.org
Date: Tuesday, January 4, 2011, 7:06 AM

Bees in freefall as study shows sharp US decline
http://www.guardian.co.uk/environment/2011/jan/03/bumblebees-study-us-decline

Disease and low genetic diversity might have caused US bumblebee
decline over the past few decades, say scientists


The abundance of four common species of bumblebee in the US has
dropped by 96% in just the past few decades, according to the most
comprehensive national census of the insects. Scientists said the
alarming decline, which could have devastating implications for the
pollination of both wild and farmed plants, was likely to be a result
of disease and low genetic diversity in bee populations.

Bumblebees are important pollinators of wild plants and agricultural
crops around the world including tomatoes and berries thanks to their
large body size, long tongues, and high-frequency buzzing, which helps
release pollen from flowers.

Bees in general pollinate some 90% of the world's commercial plants,
including most fruits, vegetables and nuts. Coffee, soya beans and
cotton are all dependent on pollination by bees to increase yields. It
is the start of a food chain that also sustains wild birds and
animals.

But the insects, along with other crucial pollinators such as moths
and hoverflies, have been in serious decline around the world since
the last few decades of the 20th century. It is unclear why, but
scientists think it is from a combination of new diseases, changing
habitats around cities, and increasing use of pesticides.

Sydney Cameron, an entomologist at the University of Illinois, led a
team on a three-year study of the changing distribution, genetic
diversity and pathogens in eight species of bumblebees in the US.

By comparing her results with those in museum records of bee
populations, she showed that the relative abundance of four of the
sampled species (Bombus occidentalis, B. pensylvanicus, B. affinis and
B. terricola) had declined by up to 96% and that their geographic
ranges had contracted by 23% to 87%, some within just the past two
decades.

Cameron's findings reflect similar studies across the world. According
to the Centre for Ecology and Hydrology in the UK, three of the 25
British species of bumblebee are already extinct and half of the
remainder have shown serious declines, often up to 70%, since around
the 1970s. Last year, scientists inaugurated a £10m programme, called
the Insect Pollinators Initiative, to look at the reasons behind the
devastation in the insect population.

Cameron's team also showed that declining species of bee had higher
infection levels of a pathogen called Nosema bombi and lower genetic
diversity compared with the four species of bee that were not in
decline – B. bifarius, B. vosnesenskii, B. impatiens and B.
bimaculatus.

The N. bombi pathogen is commonly found in bumblebees throughout
Europe but until now has been largely unstudied in North America. The
infection reduces the lifespans of individual bees and also results in
smaller colony sizes.

The reduction in genetic diversity seen in the declining bees means
that they are less able to fight off any new pathogens or resist
pollution or predators. "Higher pathogen prevalence and reduced
genetic diversity are, thus, realistic predictors of these alarming
patterns of decline in north America, although cause and effect remain
uncertain," Cameron wrote today in Proceedings of the National Academy
of Sciences.

Insects such as bees, moths and hoverflies pollinate around a third of
the crops grown worldwide. If all of the UK's insect pollinators were
wiped out, the drop in crop production would cost the UK economy up to
£440m a year, equivalent to around 13% of the UK's income from
farming.

The collapse in the global bee population is a major threat to crops.
It is estimated that a third of everything we eat depends upon
pollination by bees, which means they contribute some £26bn to the
global economy.

Other identified causes of bee decline include parasites such as the
bloodsucking varroa mite and viral and bacterial infections,
pesticides and poor nutrition stemming from intensive farming methods.

"Pollinator decline has become a worldwide issue, raising increasing
concerns over impacts on global food production, stability of
pollination services, and disruption of plant-pollinator networks,"
wrote Cameron. "In accordance with the goals of the United Nations
convention on biological diversity to reduce the rate of species loss
by 2010, such efforts to elucidate the causes and ecological impacts
of bumble bee decline, in co-ordination with informed conservation
strategies, will go a long way to mitigating further losses."

This article was amended on Tuesday 4 January 2011. The original
version suggested that inbreeding was a cause of the bumblebee's
decline; and Sydney Cameron was described as a 'he'. These mistakes
have been corrected.

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