Bee decline already having dramatic effect on pollination

caspian · Post by **caspian** » 12 Mar 2011, 10:29

Aurora wrote:Bee populations are currently thriving in urban environments.

IMO, this suggests that the liberal use of pesticides in rural areas is largely responsible for the dramatic decline in numbers.

I don't see how you can reach that conclusion from your stated assertions. Correlation is not the same as causation. Bee populations in urban areas may be increasing, but that's because a lot of new beekeepers in towns and cities have taken it up as a hobby. (As a side effect of this, the cost of buying bees and equipment has rocketed.) Hive deaths are occurring on a fairly large scale in both towns and the countryside. As recently as a winter or two ago, one in three colonies didn't make it through the winter. Varroa probably plays a major role here, but there's been encouraging research done recently to tackle this awful disease at a genetic level.

The liberal use of pesticides may be a bad thing for many reasons, but it's not been proven to be a definitive agent in the widespread deaths of bees in the last few years.

biffvernon · Post by **biffvernon** » 12 Mar 2011, 10:37

Proving that neonicotinoids are responsible is not easy but that doesn't mean it's not true. The directly lethal dose is relatively high but the idea is that at extremely low doses, a few parts per billion, the chemical acts on the bees nervous system and alters their behaviour so they lose their ability to find their way back to the hive. One has to rely on epidemiological evidence.

Aurora · Post by **Aurora** » 12 Mar 2011, 12:06

We touched on this subject a year ago.

See: http://www.powerswitch.org.uk/forum/vie ... hlight=bee

Has any serious research been carried out since then?

Post by **kenneal - lagger** » 12 Mar 2011, 14:01

We have a healthy hive on our land which is in a rural area but one which is largely common, woodland or grazing land in the immediate vicinity. There are some sprayed fields but not many in comparison to the woodland. I just hope the hive continues to be healthy as my daughter wants to get a hive of her own.

DominicJ · Post by **DominicJ** » 14 Mar 2011, 11:48

Aurora wrote:We touched on this subject a year ago.

See: http://www.powerswitch.org.uk/forum/vie ... hlight=bee

Has any serious research been carried out since then?

I've been asking from day one for stuff as simple as the number of hives lost each year, and the number of hives that survive.
For a good five years, people have screamed "we're all gonna die and its your fault Tory scum".

No basic information been provided as yet...

Aurora · Post by **Aurora** » 29 Mar 2012, 20:31

The Guardian - 29/03/12

Pesticides linked to honeybee decline

The first study conducted in a natural environment has shown that systemic pesticides damage bees' ability to navigate.

Article continues ...

fifthcolumn · Post by **fifthcolumn** » 29 Mar 2012, 20:42

I'm pretty sure I read on one of the science sites that some study in Italy (or maybe Spain) showed that it definitively *was* the neocorticonisoid-whatever-thingy that they were spraying in the air that did it. Apparently a whack of the bees fly through the cloud of vapour and get the poison attached to them which they then take back to the hive and inadvertently overdose the bee larva with it.

biffvernon · Post by **biffvernon** » 29 Mar 2012, 21:01

No the bees don't need to fly through a cloud of the stuff. Nothing is ever certain in science but the idea is this: The neonicotinoids are used as a systemic dressing on the seed. when the seed turns into a plant insects die if the eat it. But the dose that bees get when they eat the pollen or nectar is so low, order of part per billion, that it is way below the lethal dose.

However, at these sub-lethal doses the chemical, which is neuro-toxic, has subtle affects on the bees brains such as making them forget how to fly home. Result: colony collapse disorder, no heaps of dead poisoned bees but they've just gone missing.

Aurora · Post by **Aurora** » 29 Mar 2012, 21:13

biffvernon wrote:However, at these sub-lethal doses the chemical, which is neuro-toxic, has subtle affects on the bees brains such as making them forget how to fly home.

What a coincidence, beer has the same effect on me.

fifthcolumn · Post by **fifthcolumn** » 30 Mar 2012, 03:23

biffvernon wrote:No the bees don't need to fly through a cloud of the stuff..

It's not that I actually enjoy proving you don't know your stuff biff (well I *do*) but this:

http://www.upi.com/Technology_News/2012 ... 331840460/

Which quite *clearly* states the following:

"They found that honeybees that flew through the emission cloud .. were dying."

I claim my packet of crisps mate.

biffvernon · Post by **biffvernon** » 30 Mar 2012, 07:35

Oh sure, if the bees fly through a poison cloud they get poisoned.

The point is that the bees don't have to fly though the cloud and get a big dose. A sub-lethal dose of a very few parts per billion derived by a circuitous route is sufficient to to do the harm.

Here's a new report today: http://www.bbc.co.uk/news/science-environment-17535769

Post by **adam2** » 30 Mar 2012, 07:52

biffvernon wrote:Proving that neonicotinoids are responsible is not easy but that doesn't mean it's not true. The directly lethal dose is relatively high but the idea is that at extremely low doses, a few parts per billion, the chemical acts on the bees nervous system and alters their behaviour so they lose their ability to find their way back to the hive. One has to rely on epidemiological evidence.

This view was expressed in a radio programe this morning on the World Service.

woodburner · Post by **woodburner** » 30 Mar 2012, 07:58

I bet the manufacturers will come out with a statement saying there is no problem if used according to the instructions, blah blah blah...

biffvernon · Post by **biffvernon** » 30 Mar 2012, 08:06

Nothing to do with following instructions. It's that neonicotinoids destroy populations of social insects at sub-lethal doses for individuals.

Aurora · Post by **Aurora** » 31 Mar 2012, 08:45

The Independent - 31/03/12

The Government is to reconsider its refusal to ban neonicotinoid pesticides, the nerve-agent chemicals blamed for the collapse of bee colonies worldwide, the chief scientist at the Department of the Environment, Sir Robert Watson, told The Independent.

Article continues ...