New pesticides regarded as safe for bees could be causing harm to these vital pollinators when combined with fungicides being applied to crops, reported the Independent newspaper on 11 April.
In 2013, the EU introduced a partial ban on three neonicotinoid pesticides – clothianidin, thamethoxam and imidacloprid – which were linked to global bee declines. The ban on the pesticides, widely used on crops including rapeseed, maize, wheat, barley and oats, was widened to all outdoor use in April 2018. Flupyradifurone, sold by German chemical firm Bayer under the brand name Sivanto, had been marketed as as a safer insecticide, the Independent wrote
However, a study by University of California scientists found that exposing honey bees to realistic doses of flupyradifurone in combination with a common fungicide led to abnormal behaviour and death in many of the bees tested.
The EU authorised flupyradifurone and another pesticide, sulfoxaflor, in 2015.
The Pesticide Action Network said both chemicals were so similar to neonicitinoids that it was wrong to consider them separately.
Sivanto was available in Greece, Italy, the Netherlands and the USA, the Independent said.
A spokesperson for Bayer told the newspaper that the product “is one of the latest innovations that further our commitment to bee health and it has been approved for use by governments around the world because of its effectiveness in protecting crops from damaging pests while not posing risk for honey and bumble bees colonies when used as directed”.
"The principle behind the observations reported by the new research (synergistic effects of certain fungicides increasing the toxicity of certain insecticides) are well known to us. We have implemented restrictions for the use of flupyradifurone with azole fungicides in order to prevent this type of effect under practical use conditions."
Both Bayer and Swiss agrochemical company Syngenta appealed against the EU’s neonicotinoid ban but the EU General Court upheld the bloc’s decision in May 2018.