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Pesticide cocktails found in puddles on Austrian farmland endanger bees

One in four puddles sampled contained a cocktail of of thiacloprid and azole fungicides in dangerous combinations for bees. The risk to bees, of these insecticidal cocktails, must be considered in all risk assessments for pesticide registration.

In the last two weeks of May 2015 in Vienna, Lower and Upper Austria, Burgenland, Styria and Carinthia, Global 2000 collected a total of 32 samples from puddles that had formed as a result of strong local rains on farmland. The samples came from puddles in fields growing: corn, rapeseed (canola), soybean, cereals, fruit and field vegetables. Wine-growing areas were sampled, as well as an area adjacent a private house garden being studied at the food research institute (LVA) Klosterneuburg on pesticides.

Overall, we found 58 different pesticides in the 32 puddles sampled, including: many different weed killers, fungicides and insecticides. Some of these pesticides were found in high concentrations, suggesting a recent application, but they were also found in trace amounts, originating either from historic pesticide treatments or long term contamination of the soil.

For example, in almost all water samples examined, we found degradation products of atrazine; a herbicide that was banned throughout Europe in 1995 because of its chemical persistence. Despite this long term ban, we found traces of Atrazine in almost all the puddles, 19 years after it was banned.

One in four puddles contained a dangerous cocktail of thiacloprid and azole fungicides

We found an average of ten different pesticides in every puddle sampled. Every fourth puddles cocktail contained a fatal pesticide dose for bees, due to the combination of the hitherto banned neonicotinoid Thiacloprid and a fungicide from the group of the azole fungicides.

Thiacloprid is said to be tolerated by bees, because bees, as opposed to most other insects, have a mechanism to partially detoxify this neonicotinoid.

However as laboratory tests have shown, antifungal agents from the group of the azole fungicides can block these detoxification mechanisms, thus increasing the bee-toxicity of thiacloprid by 100 to 1000 times. The fact that we found this combination of both pesticides in 8 out of 32 pools, is troubling.

EFSA: Arable puddles as a main pathway of pesticide exposure for bees

Honeybees collect water to drink and cool the hive; if the weather is hot each hive may collect up to half a litre per hive each day. Pesticides may be acutely fatal to bees, depending on the dosage, or they may weaken their immune system, cripple their sense of direction or block their ability to communicate socially. Therefore, when the European pesticide registration authority EFSA advised the European Commission to ban Neonicotinoids in 2013, it also gave future guidance on how legal pesticide approval should take account of the risk of chronic or repeated sub-lethal exposure to bees.

In this guidance, EFSA cited puddles on agricultural land, as one of the main pathways of exposure to pesticides for bees, and stressed that this route of exposure must be included in assessment of the risks before licensing new pesticides.

A further improvement of Pesticide Risk Assessment for bees proposed in this EFSA guidance, suggests that in future, the risk to bees and wild bees must be taken into account before authorization of pesticides is granted.

Global 2000 asks that these recommendations, presented two years ago, must finally be made a reality; we emphasize this demand with a petition to the European Commission. We cannot afford any further delays, or any attempted dilution of the EFSA proposals on Risk Assessment, in view of the steepening decline in wild bees and the recurring colony losses in honey bees. We must act now.

For more information/sources: The results of the Global 2000 puddles tests, please visit: The EFSA guidelines for pesticide registration, please visit: The petition by Global 2000 will go throughout the day online:

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