Bees help pollinate around 80 percent of all species of flowering plants, so without them many fruits and vegetables would be unable to reproduce

German agrochemicals and pharmaceuticals giant Bayer was presented Friday with a petition of more than one million signatures urging it to stop manufacturing pesticides that are blamed for the decline in the world's bee populations.

"Bee killing is not really something that a company that is looking toward the future should do," Anne Isakowitsch, an activist for Sum of Us, an environmentalist campaign group, told AFP.

Bees help pollinate around 80 percent of all species of flowering plants. And so without them, many fruits and vegetables would be unable to reproduce, which would have catastrophic consequences for the food chain.

Hence Berlin-based Isakowitsch travelled to Bayer's annual shareholder meeting in Cologne on Friday to present the maker of agricultural chemicals with a petition of 1.4 million signatures.

The campaigners are calling on the group—best known for its Aspirin painkiller—to stop selling two substances, clothianidin and imidacloprid, that are contained in the pesticides believed to be responsible for killing bees.

The European Union has already placed a moratorium on sales of the chemicals, which are classed as neonicotinoids, since the end of 2013.

Also affected are thiamethoxam made by Swiss giant Syngenta and fipronil by another German rival, BASF.

But the four substances, marketed under brand names such as Gaucho, Poncho and Cruiser, remain freely available elsewhere in the world.

A sign reading "Let us save the bees" during a demonstration against Cruiser, an insecticide which belongs to a subclass of neonicotinoids, on October 15, 2011 in the southeastern French city of Grenoble

Nicotine attracts bees

Neonicotinoids are mostly used in seeds planted by farmers, and find their way into nectar and pollen later during flowering.

They act on the central nervous system of insects, interfering with the transmission of stimuli.

The scientific findings make for alarming reading: the chemicals can cause the bees to become disorientated, failing to find their way back to their hives. The studies also indicate the neonicotinoids can lower the bees' fertility and their resistance to disease.

According to the distinguished scientific journal Nature, bees are more attracted to plants sprayed with nicotine, which is chemically similar to neonicotinoids, than unsprayed ones.

So, it can be concluded that neonicotinoids are "a key factor in the decline in bee populations," according to an analysis of 800 different studies by the International Union for the Conservation of Nature (IUCN).

According to the IUCN, one out of every four bumblebees and one out of every 10 honey bees are at risk of dying due to the chemicals.

But Bayer, which generated 2.5 billion euros ($2.9 billion) in sales from insecticides and crop protection products last year, disagrees.

Werner Baumann, designated CEO of German chemicals and pharmaceuticals giant Bayer, at the annual general meeting on April 29, 2016 in Cologne

"Neonicotinoids are not dangerous if used correctly," a company spokesman told AFP.

Along with BASF and Syngenta, it is contesting the restrictions imposed by Brussels.

Other factors

Bayer argues that other factors are behind the decline in bee populations, such as the weather, viruses and parasites.

Jose Tarazona, head of pesticides at the European Food Safety Agency (EFSA), conceded that the decline in bee populations was "considered (to be) multifactorial."

Nevertheless, EFSA found in 2012 that the four pesticides made by Bayer, BASF and Syngenta posed an "unacceptable risk" to bees.

"But we have no scientific tool yet to quantify their effects," he said, adding that EFSA was "working on that".

EFSA is currently reviewing the latest scientific knowledge on the issue and is expected to present its findings in 2017.

And depending on what they are, all options are still open for Brussels, which could tighten the restrictions still further, maintain them or even lift them.

"We will never say that pesticides are the only problem," said Marco Contiero, policy advisor for agriculture and genetic engineering at Greenpeace.

"There are a number of reasons but pesticides are the only one on which we can intervene immediately," Contiero said.

"The scientific studies have been so clear that I think it won't be easy for industry to lift this ban," the expert continued.

Greenpeace hopes the EU will ban all neonicotinoids in all their uses and urges the industry to invest in non-chemical alternatives.

Consumer pressure is also beginning to make itself felt.

In Germany, the discount supermarket chain Aldi has pledged not to sell any products containing neonicotinoids.

© 2016 AFP