Insects are vital members of our ecosystems. Unfortunately, we are experiencing unprecedented declines in insect populations all over the world with an estimated 45 per cent decline in the last 40 years. There are many factors contributing to this decline including habitat loss, overuse of insecticides and climate change.
One often overlooked factor affecting insect populations is light pollution. Although many people are aware of the concept of light pollution, few realize just how much of an impact artificial light can have.
If you’ve spent a summer evening on a porch, you’ve surely noticed the phenomenon of moths and other insects circling and bumping into a porch light.
There are two main explanations for this behaviour: some insects are attracted to the heat produced by incandescent light bulbs while other insects use the light of the moon to navigate but become confused when a brighter light source is present, resulting in erratic flight patterns around artificial light sources.
Unfortunately, once insects begin circling an artificial light source, it becomes almost impossible for them to escape. This causes one in three insects attracted to artificial light to die before morning.
The good news is that you can help reduce this problem.
Studies show that certain types of light bulbs can significantly reduce the number of associated insect fatalities. LEDs are better than incandescent light bulbs because they do not produce any heat. Light colour also matters, so opt for warm-coloured LEDs (yellow/orange tinted) over cool-coloured LEDs to attract fewer insects.
Finally, the best and simplest option to reduce the harms of light pollution is to turn off any unnecessary outdoor lights.
Editor’s note: Nature Notes is a monthly column produced by the Delta Naturalists and their community partners. For info on monthly meetings and more see www.deltanaturalists.org and www.facebook.com/DeltaNats/.
