The question of whether or not LED bulbs attract insects is arising more and more frequently, and various discussions arise about the answer. However, the truth lies in the middle. Yes, LED lamps have a beneficial effect on insect attraction. No, LED lights cannot completely prevent you from not being accompanied by Mother Nature. The fact is that no light source can prevent insect attraction. But what then is this romantic relationship between light and insect?
Insects are attracted to natural light from the sun and moon, which supports their instincts to navigate. In addition, they are sensitive to changes in temperatures which, among other things, explains their attraction to artificial light and results in the swarms you see under street lights in the evening. So insects, like humans, need warmth and light.
But what makes light interesting to insects?
Several scientific studies have been done on the attraction of light towards insects. One is a study conducted by the Department of Entomology in Pakistan which was conducted to help develop light insect traps (instead of pesticides) for the agriculture industry. This study revealed the following:
Unlike humans, insects can see other aspects of light. Compared to humans, this perceptible part, is almost as limited. The colours they particularly see are UV, green and blue, also known as the cooler shades of the light spectrum. They have more difficulty with the warmer colours like orange, red and yellow. So they are not necessarily attracted to light in general, but to the colour spectrums. If we were to specify this further according to the study, it was found that 22% of the insects were attracted by blue tones, 18% by white, 10% by yellow, 4.7% by green and 2% by red tones.
So if we start looking at the wavelengths of these colours, it means that the shorter wavelengths are more attractive to the insects. The wavelength is measured in nanometres and the cooler colours register 300-650 nanometres. The warmer colours to UV light measure between 400-800 nanometres. Below is a graphic explanation of the light spectrum and the difference between a human and insect’s perceptions.
400 – 800 nanometres
- The light that humans can see
- This ranges from the colour violet to red
- This part of the spectrum contains no UV light
350 nanometres
- Ultraviolet light
300 – 650 nanometres
- The light which insects can see and which attracts them
- This part of the spectrum includes UV light
- Insects prefer light between 300 and 420 nanometres.
What does this mean for the traditional light bulb?
The light from traditional light bulbs often contains cooler tones and emits relatively high levels of heat. 90% of the energy of incandescent and halogen bulbs is converted into heat, making them very attractive to insects that use heat receptors to navigate. A well-known example of an insect that uses heat receptors is the mosquito. It sees a change in temperature as a sign of a food source and thus goes there. So if you want to avoid leeches, a lower fluctuation in temperature is important.
And what about this with LED bulbs?
An average LED lamp is less attractive, as it often produces longer wavelength light. In addition, LED lamps are a lot cooler in temperature and therefore cause less temperature fluctuations. We should also not forget to mention that LED lamps often emit little or no ultraviolet radiation. So LED lamps are often not only much more efficient, but we have a definite effect on insect attraction.
Can a festival of insects be prevented? No. So that also means that no manufacturer can claim to have designed a lamp that does not attract insects. Can it help reduce the insect festival? It certainly can!
