Bijensterfte, oorzaken en gevolgen

Honey bees vital for agricultural industry
Sue Kedgley, New Zealand Herald 4 May 2009

New Zealand is slowly waking up to the realisation that honey bees are indispensable to our agriculture, horticulture, environment and economy.

Without them, we would have a gravely reduced food supply. Yet, few among us are aware of the huge threats bees face.

New Zealand's most famous son, Sir Ed Hillary, was once a beekeeper.

Despite this, there hasn't been much interest in our beekeeping industry, and it has largely operated under the radar.

But sharp declines in populations in the US, Canada and Europe have sparked global concern about bees, and the future of the world's food supplies if they continue to be decimated, as bees are essential to pollination and food production.

The International Bee Keeping Body has warned that Europe's beekeeping industry could be wiped out in less than a decade, as hundreds of thousands of bees there are falling victim to disease, insecticides and intensive farming.

In some parts of Europe 80 per cent of bees were poisoned last year.

Bee losses overseas have triggered concern in New Zealand, where our bees have already been devastated by varroa mite, an exotic invader that destroys them in their hives.

The story of how varroa sneaked into New Zealand in the mid-1990s and spread throughout the country is well known. What is less well known is that the bee industry is facing an even more disastrous threat - a problem known as colony collapse disorder.

This surfaced in the US several years ago, and shortly afterwards in Europe. Whole colonies of bees simply disappeared. The bees vanished suddenly, with few or no dead adults in or near the colonies, leaving behind the queen bee and a few young ones.

Tens of thousands of bee colonies were wiped out in the US in 2007 and similar losses have occurred in the UK.

Various theories have been put forward to explain the sudden disappearance, including parasites, bacteria, viruses and electromagnetic radiation. The vulnerability of the modern bee, bred with a narrow genetic base, overworked and propped up with a suite of protein and energy supplements, and often transported round the globe, has made bees more susceptible to all these problems.

But pesticides began to emerge as a prime suspect following scientific testing of bees after a spate of honeybee deaths in France and Germany - particularly insecticides that are acutely toxic to the nervous systems of bees.

In 1994, France's honey bee population crashed. Four times more bees than normal died. Those that didn't vanish behaved strangely or seemed paralysed. That was the year France introduced the insecticide imidacloprid as a seed dressing on sunflowers. The French Government banned it in 2004. By this time an estimated 90 billion bees had died and honey production was reported to have been reduced by up to 60 per cent.

Across the border in Germany, tests on dead bees showed a similar build up of a similar pesticide sold under the trade name Poncho. In May last year, Germany banned eight insecticides used as seed dressings, and Italy followed suit.

These powerful new insecticides, known as neonicotinoids, are widely accepted as a factor behind colony collapse disorder.

They are systemic chemicals which work their way up from the seed, through the plant as it grows and into the pollen and nectar. They are powerful neurotoxins for bees dining on the nectar and collecting the pollen, and that is why most European beekeepers believe they are largely to blame for the decline in their bee numbers.

Another concern is that more than 70 pesticides and pesticide metabolites have been found in pollen and bees in the US. The theory is that, although they may not be killing the bees, they are weakening the immune system and making them more susceptible to the varroa mite and a host of other parasites and diseases.

There are 32 pesticides that are highly toxic to bees registered for use in New Zealand. They are contained in more than 140 formulations, or about 11 per cent of all pesticide products registered here.

They include popular home garden products from Yates, Watkins and Garden King, a few household products such as No Flies Super, but many are used in our horticultural and agricultural sectors, products like Dursban, Confidor, Crusier and Poncho.

The European Parliament has recently adopted stringent regulations which will phase out all pesticides that are highly toxic to bees. They come into effect in September.

New Zealand must follow their lead, and phase out all pesticides that are acutely toxic. Bees are so important to our economy, our ecology, our agriculture and horticulture that we cannot continue to use pesticides that we know are acutely toxic to bees. Nor can we afford to wait until the bees are dying en masse before we act.

About a third of all the food we eat relies on honey bees for pollination.

Even the livestock industry would be affected by the loss of forage crops and pasture plants, like alfalfa and clover.

That's why the Green Party is calling on the Government, during Bee Week, to commit to phasing out all 32 pesticides used that are highly toxic to bees. If Europe can do it, we must too, especially when our economy is so dependent on agriculture.

We are also calling on the Government not to allow honey imports that could bring in new and unwanted viruses such as Israel acute paralysis virus, parasites such as Nosema ceranae and bacterial diseases such as "foulbrood". We must maintain stringent biosecurity procedures to protect our bees from biosecurity threats at the same time as we dramatically lessen the poisons in their environment. The "laundering" of honey from countries such as China and Argentina, through third countries like Australia, poses a threat.

* Sue Kedgley is a Green Party spokeswoman on food safety and the environment

Bron: The New Zealand Herald, 4 May 2009