In the past few decades, global warming and climate change have done a big damage to pollinators, including bees, beetles, moths, flies, etc., around the world. The population of bees and other pollinators worldwide is also declining due to pesticides, diseases, introduced parasites, and loss of habitats. While that was not enough, an increasing amount of light pollution has now started impacting the pollination of flowers. A new study carried out by researchers from the Institute of Ecology and Evolution at the University of Bern suggests that pollinators that are active during night time don’t prefer visiting flowers that have artificial lighting near them.

The researchers also feel the need for further such studies to investigate the long-term effects of artificial lighting on pollination losses.

Light emission is increasing by a rate of 6 percent annually

According to experts, light emission has increased by around 70 percent in the past two decades, specifically in residential areas, and it continues to increase by about 6 percent annually.

In the current study, researchers observed nocturnal pollination in cabbage thistle (Cirsium oleraceum) being grown on 14 meadows in Switzerland’s pre-Alps area. Seven of these meadows were experimentally illuminated with mobile LED street lamps, while no street lamps were used in rest of the meadows. The pale flower heads of cabbage thistle are rich in nectar, and therefore a large number of insects visit these flowers during the day as well as night time.

According to researchers, they observed that meadows, where artificial lighting was used, were 62 percent less frequently visited by pollinators compared to meadows that were unlit. The experiment also suggested that there were 29 percent fewer pollinators in illuminated meadows compared to unlit areas.

Daytime pollinators are also affected by the artificial lighting

Disturbingly, the study also revealed that even the diurnal (daytime) pollinators are indirectly affected by the artificial lighting. Because diurnal pollinators can’t compensate the loss of night time pollination, there is less fruit production—meaning fewer food sources for the diurnal pollinators themselves.

The researchers also feel that more studies are needed to investigate the long-term effect of artificial lighting on pollination losses. The detailed findings of the study have been published in journal Nature.