In a study, UCL researchers found that exposure to bursts of bright light improve survival rates of bees suffering from neonicotinoid poisoning; exposure to neonicotinoids usually affects bees’ ability to produce energy for their cells, reducing their mobility, and leading them to die of starvation.

The researchers used four groups of bees from commercial hives, with more than 400 bees in each colony. Two groups were exposed to a neonicotinoid, Imidacloprid, for ten days, with one group also being treated with light therapy over the same period - 15 minutes of near infrared light (670nm) was shone into the hive twice daily.

The mobility of the bees that were poisoned but not treated with light therapy dropped off rapidly, as did their energy production, and so their survival rate dropped off. The bees that were poisoned but also treated with light therapy had significantly better mobility and survival rates, living just as long and functioning just as well as bees that had not been poisoned. One group was given light therapy without being poisoned, and their survival rate was even better than the control group. The researchers found the deep red light did not interfere with bee behaviour as they cannot see it.

Professor Glen Jeffery, who was a senior author of the study, said, ”Neonicotinoid pesticides are a persistent threat to global bee populations, which play a critical role in agriculture. My team is working to develop a small device that can be fitted into a commercial hive, which could be an economic solution to a problem with very widespread implications." "Long-wavelength light treatments have been shown in other studies to reduce mitochondrial degeneration which results from aging processes. It's beneficial even for bees that aren't affected by pesticides, so light therapy can be an effective means of preventing loss of life in case a colony becomes exposed to neonicotinoids. It's win-win.”

Professor Jeffery said the light treatment works best as a preventative measure, as it has beneficial effects on bee health anyway, but they believe it can be used in response to poisoning, so long as the treatment is started within a couple days of exposure.

The researchers were studying near-infrared light therapy because it has been shown to benefit other animals including humans, particularly in countering effects of aging and a range of neurological diseases.

"When a nerve cell is using more energy than other cells, or is challenged because of a lack of energy, red light therapy can give it a boost by improving mitochondrial function. Essentially, it recharges the cell's batteries," Professor Jeffery explained.

The UCL researchers released a video (below) of their experiment, which shows bees exposed to Imidacloprid: The bees on the right in the video have been treated with red light therapy, and appear to be functioning well, but the bees on the left are not flying, and their loss of mobility has reduced their ability to groom themselves, meaning their fur has stuck together and they have lost their yellow coloration.