What Are Bug Light Bulbs? Are They Effective in Repelling Insects?

Many flying insects are naturally drawn to sources of bright light. Moths and other insects gathered around bulbs and other sources of artificial light are familiar, especially during summer. Common strategies to repel these bugs include citronella candles, sprays, or torches. In some local hardware stores, yellow-colored bug light bulbs are promoted as solutions to bug problems.

How Do Bug Light Bulbs Work?

Bug light bulbs are lamps with filtered yellow glass to prevent insects from getting attracted. They come in various wattages, voltages, and sizes and are generally used outdoors, although they can also be used anywhere where insect attraction is a primary concern.

Insects and humans do not perceive light in the same way. As a form of electromagnetic radiation, light is divided into multiple wavelengths, measured in nanometers (nm). The human eye can only perceive a small portion of the electromagnetic spectrum, known as visible light, which ranges from 400 to 700 nm. On the other hand, insects perceive an equally small band of vision, but theirs is inclined toward the shorter end of the spectrum, closest to ultraviolet light.

Physics explains that the wavelength of light is inversely proportional to color temperature. This means that as the wavelength of light decreases, its color temperature increases. Among the light colors, red and yellow have low temperatures and long wavelengths, while blue and violet exhibit high temperatures and short wavelengths.

In bug light bulbs, the manufacturer intentionally coats the bulb with yellow color to decrease the color temperature of light that they emit. As a result, the wavelength is longer than the visible spectrum of flying insects.

Are Bug Light Bulbs Effective in Warding Off Insects?

The widespread use of residential lamps has created artificial light ecologies affecting some species of insects. In our modern times, artificial light sources have become common in most households, although it also means that more and more insects are getting attracted to them.

Choosing the right type of bulb can solve this problem, as suggested by a 2016 study. In this research, ecologist Michael Justice performed a summer-long experiment focusing on the difference in the attractiveness of six common store-bought light bulbs.

By the end of the summer of 2016, Justice was able to capture a total of 8,887 insects in his light trap. He observed that some bulbs are much more attractive to insects than others.

The result of the study reveals that traditional incandescent bulbs are the option for outdoor lighting since they tend to attract bugs. Meanwhile, the best bulb that is least appealing to insects would be the warm-colored bulb that generates a yellow or orange hue rather than the cool blue light.

However, it should be noted that bug light bulbs do not kill insects, nor do they repel bugs that gather around them. They attract fewer insects than any other type of light bulb. In short, it makes your home less visible to most flying bugs.