Monsanto’s “Bee Summits” and Bayer AG’s “Bee care centre” are the latest examples of how pesticide makers are competing to showcase their goodwill to policymakers in Europe and the US that they are taking the necessary steps to protect bee populations. The companies say their pesticides are not the problem, but critics say science shows the opposite, EurActiv reported.

The European Union announced earlier this month it would ban the class of pesticides known as neonicotinoids, or "neonics," used for corn and other crops as well as on home lawns and gardens. The ban is in place for two years.

Similar constraints in the United States could cost manufacturers millions of dollars in sales.

As a result, Monsanto is hosting a "Bee Summit." Bayer AG is breaking ground on a "Bee Care Centre." And Sygenta AG is funding grants for research into the accelerating demise of honeybees in the United States.

Die-offs of bee populations have accelerated over the last few years to a rate the American government calls unsustainable. Honeybees pollinate plants that produce roughly 25% of the foods Americans consume, including apples, almonds, watermelons and beans, according to government reports.

Scientists, consumer groups, beekeepers and others blame the devastating rate of bee deaths on the growing use of pesticides sold by agrichemical companies to boost yields of staple crops such as corn. Monsanto, Syngenta, Bayer and other agrichemical companies say other factors such as mites are killing the bees.

"This is a difficult, high stakes battle," said Peter Jenkins, a lawyer with the Centre for Food Safety, which sued the US Environmental Protection Agency (EPA) in March on behalf of a group of beekeepers and environmental and consumer groups over what they say is a lack of sound regulation of the pesticides in question.

"They may have a lot of money. But... we're going to win," Jenkins said.

The uproar worries officials at Bayer and Syngenta, who make the pesticides, as well as Monsanto, DuPont and other companies who used them as coatings for the seed they sell.

"Everybody is concerned by it," said Monsanto Chief Technology Officer Robert Fraley in an interview.

Monsanto plans to host a summit in June for experts from around the country to analyse the issue and discuss potential solutions. Bayer is breaking ground on a facility in North Carolina to study bee health.

"We are concerned... that the science sometimes gets trumped by the politics," said Dave Fischer, an ecotoxicologist at Bayer CropScience who is meeting with bee keepers and studying the bee deaths. He said critics "are searching for a culprit."

The companies point to a vicious insect mite as one of many factors harming the bees.