Individual bees are very delicate organisms in the strong and resistant body of a colony inside its carefully protected cavity since long before man first stepped on earth (Free et.al.). The individual bee will freeze to death within minutes in the climate of Sweden where I keep bees since 28 years. But colonies of bees have survived my mismanagement, infestation with waxmoths, queenlessness, wet insulation or even being tipped over during a chilly winter storm. Some of my colonies always survived and managed to multiply when the sun at spring brought flowers and nutritious food back into the life cycle again. The winter losses never ever surpassed 15 % until last year.

The winter 2002-2003 was a totally new experience for me and for thousands of my colleagues in countries like Austria, Germany, Belgium, Denmark and Finland. I lost 50 colonies out of 70! Only 20 survived. One neigbour lost 95 of 120, someone else 24 of 25 etc.etc.

Some colonies died already in december. I found colonies that had just stopped living. The had given up life without any sign of struggle. They were dead without visible reason. They had plenty of good sugarfeed. Pollen store was available. The queen was sitting dead in the midle of the cluster. Other colonies tried to survive but gradually dwindled away with less and less bees and finally gave up before the warm weather could help them to recover.

I had a terrible job to clean up all the dirty comb and contaminated hives. The combs had to be brushed off before being melted in water so that the sugar remains could be separated from the pure wax. It is always a depressing job to take care of dead bees knowing their important task for maintaining good pollination in our neighbourhood.

Our national beekeeper federation, SBR reacted without delay and organised an instant survey to a random sample of 2.520 beekeeprs (Kristiansen 2003). From the 1.654 answers received we can conclude that the colony losses in my county was about 36 %. The national average was "only" 20 %. A similar survey to 6.072 german beekeepers came up with an average of 29 % winter losses the same winter (Otten 2003). The swedish survey could not conclude any particular cause of the winter death but rather the speculation that the event was a combination of several unfavourable circumstances during the season 2002.

There are however several observations that can outrule some of the theories proposed initially:
 

	Both experienced and less experienced beekeepers had problems.
	The death toll was high also in areas where the varroa parasite has not yet arrived.
	The death toll was high also in areas where other diseases such as foulbrood, sacbrood, chalcbrood or nosema are rarely seen.
	The death toll was high also for colonies in very well insulated beehives.
	The winter death was very low in the forest areas of northern Sweden but at the same time very high in the farmland area in northern Finland.
	The death toll was high both in areas affected by the radioactive Cesium137 downfall from the Chrernobyl accident as well as in other areas not affected.

So we are many beekeepers that has hoped until now that the scientists are correct, that it was an extreemly bad year of a kind that can appear once in a while. But is it really like that?

The sun is now warming up the hive bodies and the snow is rapidly melting away. The first Crocus are biginning to provide pollen and Salix will soon follow. A first summary of my remaining colonies is again a catastrophy!!! Only 17 colonies surviving out of 30!!! And some of the survivors are very weak and may not make it another 2-3 weeks. My phone is ringing. Beekeeper friends are reporting: 7 of 8 dead, all but 2 dead, more than 50 % dead and so on. It is to early to see if this is as serious a problem as last year, but this time I am not going to wait raising my voice.

We have to find resources and support to find out what is happening to our bee environment. What are the possible explanations? How can researchers join hands in order to clear out how to prevent and overcome these problems? In order to trigger off the discussion I would like to present a list of possible explanations that can be thinned out or extended with contributions by those who have a better general view than myself. Please feel free to join the debate with your own observations or theories!

1. The European Commission has decided to allow use of a number of doubtful pesticides. Some of these were banned in Sweden for many years such as Amitrole, 2,4-D, Linuron, Mecoprop, Paraquat, Propineb, Thiram and Bromoxynil. Some of these are extreemly hazardous to man but the objections from our government chemistry authority had no effect on the descision makers in Brussels. These pesticides are mainly herbicides and fungicides and most likely we will not find one of them that is used all over the affected region.

2. The European Commission has authorised a large number of new pesticides for an even larger number of different uses without adequate hazard testing. The new generation of pesticides can be generalised as: 1. Low dosage, 2. Long persistence, 3. Systemic action, 4. Difficult to detect in laboratory tests. The swedish government authority is also complaining in their annual report (KI, 2003) that it is difficult to keep track of the different pesticides due to many changes of ownership within the private sector.

3. The aphid pests (Megilethes spp.) on oil-seed rape has developed resistance to the most popular pyretroid pesticides. Therefore the chemistry authority again approved use of the extreemly bee poisonous insecticide Fenitrothion (Sumithion or Folithion) from year 2001. This pesticide was banned more than 20 years ago due to its enormous risks for bees, other insects and aquatic life.

4. The use of insecticides increased in Sweden 2001-2002 by 250 %. A possible reason is that the warm summers (global warming?) caused heavy growth of aphid colonies in many grain crops.

5. A new range of pesticides has enterred the market the last 5 years. These are all based on the active ingredient Imidakloprid, a chemical that affect the digestive neurosystem of insects. Popularly we can say that insects that get in touch with these products loose their apetite and stop being harmful to crops. These insecticides have long persistence and a systemic effect. It is therefore possible that the harmful effect will occur over a long period and only slowly in a bee colony consuming its stored reserves of plant material during winter. The treeted seed will for instance germinate in august 2004, the plant will flower in June 2005 and bees will collect and store contaminated nectar and pollen that can cause indistinct symptoms during the winter 2006, one year and a half after! Here is a list of Imidakloprid products being registered in Sweden:
 

	Chinook for seed dressing of oil-seed rape seed.
	Gaucho and Montur for seed dressing of sugar beet seed.
	Prestige for dressing of potatoe seed before planting.
	Confidor for treatement through irrigation water in green houses (ornamental plants, tomatoes, cucumber and sweet pepper).
	Merit Forest for treatment of forest plants against insect attacts.
	Some products are also registered for indoor plant use in homes as dip sticks.

Commercial representatives also confirm that these products have been tried as seed dressing on wheat and oats. They are however not willing to disclose to what extent farmers are using seed treated with these chemicals. In France Imidakloprid pesticides have been banned for use on sunflower crops after heavy protests from beekeeper groups.

6. Pesticides in sugar cultivation or industrial manipulation of white sugar may be another foreseen problem for bee colonies. Use of the above mentioned systemic seed dressers on sugar beet seed (point 5.) or insecticides on sugar cane fields can be a hidden problem. Also new techniques for extraction or bleeching of white sugar may cause a possible hazard to bees. An increasing trade with sugar products has also been noted.

7. Extensive use of desciccants (Glyfosat, Rambo, Roundup) for total kill of weeds instead of mechanical cultivation. The total usage of these herbicides has increased four years in a row. This is remarkable since the increase of Glyfosat products used took place at the same time as the acreage of ecological farming also increased. This must imply that the intensity of Glyfosat usage has increased on the farmland that is still cultivated with chemicals. Several Glyfosat products are also registered for use by laymen in ordinary gardens.

8. Increasing downfall from burning of household waste material as an energy resource. A new government fee on dumping of waste products has created an enormous interest for the household waste as an important energy resource. Large municipal heat and power plants have been convereted from charcoal and crude oil to household waste and other biomass sources. The disadvantage with this quick change is that the cleaning techniques for many dangerous organic substances in the smoke are still rudimentary. In some cases we do not even know what to look for? The amounts of downfall may be very small but still extreemly hazardous to human and other life from the very stabil organic substances that come with the smoke from waste burning. Examples of such substances are PCB, Toxafen, Dioxin, halogenated flame retardants, nonylphenol, organic tin compounds, phthalates and secondary residues of all these products etc.

I do not claim that I have any proof for any of the above theories, but I instead that it is utmost important that we try to find out the cause for the winter death in bee colonies during the last two years. Will my bees survive another winter like this? Or will we meet a silent spring next year?

If bees cannot survive can we?

Börje Svensson,
Beekeeper, Sala, Sweden
borje.svensson@ltvastmanland.se

References:
 

	Adey, M.: Walker, P.: Walker, P.T. (1986) Pest control safe for bees: a manual and directory for the tropics and subtropics, IBRA, London, UK
	Crane, Eva (1990) Bees and Beekeeping, Heinemann, Oxford, UK
	Free, John B ed.(?) Honeybee Biology, Central Association of Bee-keepers Publications, Ashford, UK
	Hertz, Ole (1995) Bees and pesticides, Beekeeping & Development (34/1995), pp. 7-10
	Kemiinspektionen (2003) Sold quantities of pesticides 2002, KI, Stockholm, Sweden
	Kristiansen, Preben (2003) Vinterförlusterna 2002/2003, Bitidningen (7-8/2003), pp. 13-14
	McGregor, S.E. (1976) Insect pollination of cultivated crop plants, Agriculture Handbook No. 496, USDA, Washington D.C., USA
	Otten, C (2003) Daten und Fakten zu den Völkerförlusten, ADIZ 37 (8/2003), pp 6-8