UCL Institute of Ophthalmology


Institute of Ophthalmology research finds that light therapy could save bees from deadly pesticides

20 December 2016

Bee exposed to Imidacloprid, with bent front legs, withdrawn antenna, and matted fur causing loss of yellow colouration. Source: Study authors…

Institute of Ophthalmology research has found that treating bees with light therapy can counteract the harmful effects of neonicotinoid pesticides and improve survival rates of poisoned bees.

According to the researchers, neonicotinoid pesticides are a persistent threat to global bee populations, which play a critical role in agriculture. The pesticides undermine mitochondrial function and affect the production of ATP, the currency for energy that drives cellular function. As a result, bees exposed to neonicotinoids suffer reduced mobility, leading them to die of starvation.

The study, published in PLOS One journal, used four groups of bees from commercial hives with more than 400 bees per colony. Two groups were exposed to Imidacloprid, a neonicotinoid, for ten days, with one group also being treated with light therapy over the same period. The light therapy consisted of 15 minutes of near infrared light (670nm) being 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 ATP levels, and their survival rate declined accordingly. 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.

The senior author of the paper, the IoO’s Professor Glen Jennery, said: “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.”

While light therapy works best as a preventative measure, the researchers found it can also be helpful as treatment in response to an incident of pesticide exposure, because it improves mitochondrial and visual function - as long as the treatment is started within a couple days of exposure.

Researchers at UCL Ophthalmology have been studying near-infrared light therapy because of its benefits not only for bees, but also for other animals including humans, particularly to counteract 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 explains.

The study was funded by the Biotechnology and Biological Sciences Research Council (BBSRC).