Bees for Development Journal 71

Silent Spring in Northern Europe?Borje Svensson, Sola, Sweden

Individual bees are very delicate organisms existing within thestrong and resistant body of their colony, inside its carefullyprotected cavity. Honeybees have been surviving this way sincelong before man first stepped on earth (Free et a/., 1 982}. Anindividual bee will freeze to death within minutes in the climateof Sweden where I have been keeping bees for 28 years.Colonies of bees have survived my mismanagement, infestationwith wax moth, queenlessness, wet insulation, or even beingtipped over during a cold winter storm. Some of my coloniesalways survived and managed to multiply when the spring sunshone and brought flowers and nutritious food back into the lifecycle again. Winter losses never ever exceeded 15% - until lastyear.

Unwelcome experience

Winter 2002-2003 was a totally new experience for me and for"0*ousands of my colleagues in countries like Austria, Belgium,

jnmark, Finland and Germany. I lost 50 colonies out of 70!Only 20 survived. One neighbour lost 95 out of 1 20, someoneelse 24 of 25 and so on.

Some colonies died even in December. I found colonies that hadjust stopped living. They had given up life without any sign ofstruggle. They were dead without visible reason. They had plentyof good sugar feed. Pollen stores were available. The queen wassitting dead in the middle of the cluster. Other colonies tried tosurvive but gradually dwindled away with less and less bees andfinally gave up before the warm weather could help them torecover.

I had a terrible job to clean up all the dirty comb andcontaminated hives. The combs had to be brushed off beforebeing melted in water so that the sugar remains could be

Bor/e Svensson

separated from the pure wax. It is always a depressing jobdisposing of dead bees knowing their important task formaintaining good pollination in our neighbourhood.

Immediate survey

Our National Beekeepers' Federation, SBR, reacted withoutdelay and organised an instant survey within a random sampleof 2,520 beekeepers (Kristiansen, 2003). From the 1,654responses we can conclude that the colony losses in my countywere about 36%. The national average was 'only' 20%.

A similar survey of 6,072 German beekeepers came up with anaverage of 29% winter losses during the same winter (Often,2003). The Swedish survey could not make any conclusionsabout any particular cause of the winter'deaths but ratherspeculated that the event was a combination of unfavourablecircumstances during the season 2002.

However there are several observations that can rule out someof the theories proposed:

1. Both experienced and less experienced beekeepers hadproblems.

2. The death toll was high in areas where the Varroa parasitehas not yet arrived.

3. The death toll was high in areas where other diseasessuch as foulbrood, sacbrood, chalkbrood or nosema arerarely seen.

4. The death toll was high also for colonies in very wellinsulated hives.

5. The winter death was very low in the forest areas of northernSweden but at the same time very high in the farmland areain northern Finland.

6. The death toll was high both in areas affected by theradioactive Cesiuml37 downfall from the Chernobylaccident as well as in non-affected areas.

More bad news

So we are many beekeepers who have hoped until now that thescientists are correct: that it was an extremely bad year of a kindthat appears once in a while. But is it realiy like that? The sun isnow warming up the hive bodies and the snow is rapidlymelting away. The first Crocus flowers are beginning to providepollen and Sa//x will soon follow. A first summary of myremaining colonies is again a catastrophe!!! Only 1 7 coloniessurviving out of 30!!! And some of the survivors are very weakand 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 too early to see if this is asserious a problem as last year, but this time I am not going towait before raising my voice.

Possible explanations

We have to find resources and support to find out what ishappening to our bee environment. What are the possibleexplanations? How can researchers join hands to determine howto overcome these problems? To start the discussion I would liketo present a list of possible explanations that can be thinned outor extended with contributions by those who have a better view.Please join the debate with your own observations or theories.

Bees for Deve/opment Journal 71

1. The European Commission has decided to allow use of anumber of doubtful pesticides. Some of these were bannedin Sweden for many years: 2,4-D, Amitrole, Bromoxynil,Linuron, Mecoprop, Paraquat, Propineb and Thiram.Many of these are extremely hazardous to humans but theobjections from our government chemistry authority had noeffect on the decision makers in Brussels. These pesticidesare mainly herbicides and fungicides and most likely we willnot find one of them that is used all over the affected region.

2. The European Commission has authorised a large numberof new pesticides for an even larger number of different useswithout adequate hazard testing. The new generation ofpesticides can be generalised as: i) low dosage, ii) longpersistence, iii) systemic action, iv} difficult to detect inlaboratory tests. The Swedish government authority is alsocomplaining in their annual report (Kl, 2003) that it isdifficult to keep track of the different pesticides due to manychanges of ownership within the private sector.

3. The aphid pests (Megilethes spp) on oil-seed rape havedeveloped resistance to the most popular pyrethroidpesticides. Therefore the chemistry authority again approveduse of the extremely bee poisonous insecticide Fenitrothion(Sumithion or Folithion) from year 2001. This pesticide wasbanned more than 20 years ago due to its enormous risksfor bees, other insects and aquatic life.

4. The use of insecticides increased in Sweden 2001 -2002 by250%. A possible reason is that the warm summers (globalwarming?) caused heavy growth of aphid colonies in manygrain crops.

5. A new range of pesticides has entered the market during thelast five years. These are all based on the active ingredientImidakloprid, a chemical that affects the digestiveneurosystem of insects. Popularly we can say that insects thatcome into contact with these products lose their appetite andstop being harmful to crops. These insecticides have longpersistence and a systemic effect. It is therefore possible thatthe harmful effect will occur over a long period and onlygradually in a bee colony that is slowly during winterconsuming its stored reserves of plant material. The treatedseed will for instance germinate in August 2004, the plantwill flower in June 2005 and bees will collect and storecontaminated nectar and pollen that can.cause indistinctsymptoms during the winter 2006, one and a half yearslater!

Here is a list of Imidakloprid products being registered inSweden:

Chinook for seed dressing of oil-seed rape seed.

Gaucho and Montur for seed dressing of sugar beet seed.

Prestige for dressing of potatoes before planting.

Confidor for treatment through irrigation water in greenhouses (ornamental plants, tomatoes, cucumber and sweetpepper).

Merit Forest for treatment of forest plants against insectattacks.

Some products are also registered for use in homes as dipsticks for indoor plants.

Commercial representatives also confirm that these productshave been tried as seed dressing on wheat and oats. They arehowever not willing to disclose to what extent farmers are usingseed treated with these chemicals. In France Imidaklopridpesticides have been banned for use on sunflower crops afterheavy protests from beekeeper groups.

6. Pesticides in sugar cultivation or industrial manipulation of• white sugar may be another problem for bee colonies. Use

of the above mentioned systemic seed dressers on sugarbeet seed (point 5) or insecticides on sugar cane fields canbe a hidden problem. Also new techniques for extraction orbleaching of white sugar may cause a possible hazard tobees. An increasing trade with sugar products has also beennoted.

7. Extensive use of desiccants (Glyfosat, Rambo, Roundup) fortotal extermination of weeds instead of mechanicalcultivation. The total usage of these herbicides has increasedfour years in a row. This is remarkable since the increase ofGlyfosat products took place at the same time as theacreage of ecological farming also increased. This mustimply that the intensity of Glyfosat usage has increased onthe farmland that is still cultivated with chemicals. SeveralGlyfosat products are also registered for use by gardeners.

8. Increasing downfall from burning of household wastematerial as an energy resource. A new government fee ondumping of waste products has created an enormousinterest for using household waste as an important enerresource. Large municipal heat and power plants have beeTiconverted from charcoal and crude oil to household wasteand other biomass sources. The disadvantage with this quickchange is that the cleaning techniques for many dangerousorganic substances in the smoke are still rudimentary. Insome cases we do not even know what to look for. Theamounts of downfall may be very small but still extremelyhazardous to human and other life from the very stableorganic substances that come with the smoke from wasteburning. Examples of such substances are PCB, Toxafen,Dioxin, halogenated flame retardants, nonylphenol, organictin compounds, phthalates and secondary residues of allthese products.

I do not claim that I have any proof for any of the abovetheories. What is of paramount importance is that we try to findout the cause for the winter deaths of honeybee colonies duringthe 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?

References

Free, J.B. ed. (1982) Honeybee Biology, Central Association ofBee-keepers Publications, Ashford, UK.

Kemiinspektionen (2003) Sold quantities of pesticides 2002, Kl,Stockholm, Sweden.

Kristiansen, R (2003) Vinterforlusterna 2002/2003, Bitidningen(7-8), 13-14.

Often, C. (2003) Daten und Fokten zu den V6//cerfor/usfen, ADIZ37 (8/2003), 6-8.

STOP PRESSFrom the author - May 2004

We are beginning to see the full size of the problem now.

In my county it seems like more than 50% of colonies diedthis winter.

The media is beginning to take notice now, but some of thenews is old, as far back as 1 999 from France!