Bumblebees' ability to produce the buzzing vibration that enables them to pollinate certain plants can be affected by neonicotinoids, according to new research. The study’s preliminary findings are set to be presented at a meeting of the British Ecological Society being held in Liverpool this week.

The research looks at a pollination method that is unique to bees. In standard pollination, bees or other insects collect pollen by simply brushing against plants’ anthers (the part of the stamen that contains pollen), however, plants that require buzz pollination guard their pollen and only release it through small pores in the tip of the anther.

Dr Penelope Whitehorn, who led the research for the University of Stirling, explained buzz pollination thusly, “Bees produce a vibration – or buzz – to shake pollen out of the anther like a pepper pot. The bee lands on a flower, curls her body around the anther and grips the base with her mandibles. She then rapidly contracts the flight muscles to produce the vibration, without beating her wings.”

Crucially for growers, major food crops including tomatoes, potatoes and aubergines all require pollinating in this way.

In the Sterling experiment, Dr Whitehorn split a bumblebee colony into three groups and gave two groups different field-realistic doses of the neonicotinoid thiamethoxam, one of the three neonics subjected to heavy restrictions by the EU Commission in 2013. She then recorded the amount of pollen bees collected from plants in the lab, and measured their buzzing.

Her results show that buzzing is learned, and that the more bees practice, the more pollen they can collect over time. However, bees exposed to thiamethoxam didn’t collect more pollen over time, suggesting that the insecticide hampered their ability to learn.

Dr Whitehorn said, “The study adds to the now large body of evidence from lab and field-based studies that neonicotinoids reduce learning and memory in bees, impair their communication, foraging efficiency and immune systems and, crucially, reduce their reproductive success as well as the pollination services that they can provide. These chemicals do have serious implications for wild bee populations in agricultural landscapes but some, notably from the agrochemical industry, still promote their use.”

The Sterling study comes as fresh research from Royal Holloway University, published on Tuesday in Nature’s Scientific reports journal, showed that honeybees’ ability to forge is also affected by the controversial pesticides. PhD research by Liz Samuelson suggested that bees lose their spacial memory and navigation abilities when exposed to the pesticides, which Samuelson said could mean “Wild may be foraging less efficiently or even losing their way back to the nest.”

Both studies come at a crucial time in the debate over the future of neonicotinoids, as the EU Commission is set to review its partial ban on three pesticides in the family early next year, pending the results of a review by the European Food Standard Agency (EFSA).

Although neonicotinoid manufacturers maintain that, when used correctly, their products pose no threat to non-target insects, campaigners have pointed to the ever-growing body of evidence linking neonics with harmful effects on wildlife, including a study published in August this year and led by the UK Centre for Ecology and Hydrology (CEH), which found a correlational link between oilseed rape crops grown with neonicotinoid dressing and declines in wild bee species in Britain.