Red light could save bees from pesticide poisoning

Red lights could be easily placed in colonies and hives at a low cost, helping to reduce the impact on wild bee populations

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Shining red light on bees could reverse the potentially deadly impact of pesticides and help stop their global decline, according to new research from City, University of London and UCL (University College London).

The researchers found that when shining a specific wavelength of red light (670nm) it significantly reduced bee death rates and improved cell energy levels, mobility and visual function in animals exposed to neonicotinoid pesticides such as Imidacloprid which are widely used in agriculture worldwide.

Such lights could be easily placed in colonies and hives at a low cost, helping to reduce the impact on wild bee populations.

Bees play a key role in pollination critically underpinning the world’s agricultural economy, and many plants rely on them for pollination. However, their numbers have declined significantly over recent decades posing a threat to food production. This has been linked to the use of neonicotinoid insecticides that can remain effective in the soil for long periods and are a persistent threat to bees.

In particular, these pesticides have been shown to over stimulate bee neurons and shut down the major site of energy production - the mitochondria - in their cells resulting in immobility and death.

However, red light with a wavelength of 670nm - which appears as a deep red colour - can help kickstart these cellular powerplants as they are absorbed by an enzyme called cytochrome c oxidase that plays a vital role in the production of cellular energy in mitochondria in the form of ATP (adenosine triphosphate), which is the energy currency of the cell.

To investigate how red light can be used to mitigate the effect of these pesticides, the researchers took four groups of bees, with each group containing more than 100 bees, and studied them for a period of 32 days. This included a control; those given just pesticide; those given pesticide and also exposed to red light twice daily for 15 minutes; and then bees which were given no pesticides and treated with red light twice a day also for 15 minutes. The animals were then used to assess visual function mobility and survival.

When assessing the bees, the researchers found that bees which had been exposed to insecticide and red light showed much improved ATP levels and also significantly improved mobility allowing them to feed.

Physiological recordings from eyes revealed that light exposure corrected deficits induced by the pesticide. Overall, death rates in bees exposed to insecticide but also given 670nm light were indistinguishable from controls. Also, when the pesticide and light exposure were withdrawn, survival was maintained. Bees and insects generally cannot see deep red light so it does not disturb their behaviour.

Dr Michael Powner, a Lecturer in Neurobiology in the Centre of Applied Vision Research at City, University of London and co-author of the study, said:

“We found that by shining deep red light on the bee which had been affected by the toxic pesticides that they could recover, as it improved mitochondrial and visual function, and enabled them to move around and feed again.

“As bees play such a vital role in global agriculture and pollination, the findings could provide a really cost-effective way to protect bees from such widespread pesticides, as by placing a deep red light source in hives and colonies, it will significantly reduce death rates and preserve our bee populations.”

Professor Glen Jeffery, Professor of Neuroscience in the Institute of Ophthalmology at UCL and co-author of the paper, said:

“The great thing about this technology is that it is really cheap and simple to use. It would be really easy for beekeepers to install a simple red light system for a couple of pounds in their hives or colonies. Based on the effect we saw in the lab it could have a significant impact on populations and reduce the devastating impact of pesticides.

“But it’s not only bees where red light could have an effect, as in other studies we saw that it not only helped flies battle ageing, but also in humans it is being tested to treat age-related macular degeneration, a condition that results in blurred vision or partial vision. In mouse models of this condition the light significantly reduces the impact of the disease. As a result, its clear red light can have a huge effect, not just for bees, but for humans too.”