It is common knowledge that “light” attracts bugs. The fact that LED lamps, on the other hand, attract fewer bugs has so far been known only to very few consumers. Now LED manufacturers have commissioned a scientific study on this subject and published initial results: LED lights are the best choice when buying modern light sources for home and garden with regard to the “bug aspect”.
No sooner do you turn on the light than a flock of insects buzzes towards you when the window is open. We are not the only ones who find it annoying when the uninvited guests flutter around our heads. Artificial light is also a health-damaging factor for animals. So for the sake of both, we should avoid using light that attracts insects. But why does artificial light attract mosquitoes and bugs in the first place?
We explain what you can pay attention to, so that you are not bothered by bugs in the evening and at the same time do something for the environment.
Like moths to a flame
“Like moths to a flame” is a colloquial way of describing the state of being irresistibly attracted to something. And it is indeed the case that insects react to artificial light by flying toward the light source.
The explanation is quite simple: The insects orient themselves at night by the moonlight. They use the moon as a guide for orientation, so to speak. If a bright light is now burning in your garden, the brightest point for the insects is no longer the moon, but the lamp. The insects try to orient their trajectory to the lamp and consequently circle around it. This effect is strongest with high-pressure mercury vapor lamps and metal halide lamps.
Scientific studies on the subject of light and insects
Scientific studies on the subject of light and insects exist mainly for the field of outdoor lighting. They were conducted because of the negative effects of street lights on insect populations. The deciding factor was widely used high-pressure mercury vapor lamps, which killed millions of nocturnal insects. Subsequently, more economical and insect-friendly light sources entered the outdoor lighting market in the form of yellow-emitting high-pressure sodium lamps. With the new LED technology, energy efficiency and insect-friendliness have been further improved.
The explanation for the attraction effect of light lies not only in brightness, but primarily in the respective light spectrum of the light sources: The sensitivity of nocturnal bugs to certain spectral ranges of light differs greatly from that of humans. For example, unlike the human eye, many insect eyes are sensitive to ultraviolet radiation (UV) and shorter wavelengths in the violet, blue, and green ranges. In contrast, their sensitivity in the yellow, orange, and red wavelength ranges is lower than in humans. A lamp that shines more strongly in the long-wave range is thus less perceptible to bugs than, for example, a lamp with high light intensity in the short-wave spectrum.
Warm White LEDs are the most insect-friendly choice
A few years ago, LED technology was added as a light source that has now also been studied with regard to its effect on insects. Recent studies have shown that warm white LEDs are the most insect-friendly choice among current lighting technologies due to their light spectrum.
In the summer of 2013, an LED manufacturer commissioned an entomologist and forensic expert for ecology and entomology to carry out a comparison of insect approach specifically for household lamps.
For this purpose, light traps were set up and measurements were carried out over several weeks. Three retrofit lamps of different technology but with comparable photometric parameters such as warm white light color and brightness were considered. The results of these tests using an eco halogen lamp, a compact fluorescent lamp and a LED lamp therefore support the previous findings that LED lamps with warm white color temperature are the most insect-friendly choice.
Which light colors are bugs least attracted to?
Specific studies for the light sensitivity of a single species, such as mosquitoes, can only be carried out in laboratory conditions. Back in 2011, a study on the insect compatibility of LEDs compared to conventional light sources also showed similar results to the LED study. In this work, the approach behavior of insects was observed in Germany. Six different light sources were equipped with insect traps in the summer of 2011, emptied daily and the yield counted. Warm white LEDs achieved the best results (with the fewest insects attracted), followed by cool white LEDs. Other lamps used in street lighting with higher blue components in the light attracted significantly more insects. The study also found that mosquitoes were not attracted to the light sources.
Selecting light colors to repel bugs
A warm white LED is generally perceived as less intense by bugs. The light colors of incandescent lamps also go in the same direction. Mosquitoes must be evaluated differently. These are not attracted by light, but search for their prey via the sense of smell. They perceive breath and body odors, so they cannot be influenced by light color. Here rather special candles help, which can confuse the mosquitoes’ sense of smell as citronella candles. So bites will not be prevented by the right light. Nevertheless, it is worthwhile to pay attention to a warm white light color in the garden, so the bugs will at least not hum and buzz in your wine glass.
Do LED lights attract silverfish?
Animal “house guests” who “move in” to our home without invitation usually cause discomfort and can also have a negative impact on our health. We react particularly sensitively when we encounter unwanted lodgers in our most important place of retreat and relaxation – the bedroom. It is particularly unpleasant when you go into the bathroom at night and suddenly lots of little creepy-crawlies scurry into the cracks when you turn on the light. Therefore we took a closer look at another more common household pest and provide comprehensive information about the silverfish.
Silverfish belong to the primitive insects and have been on the move on our planet for 300 million years. They are classified in the order of ground-dwelling insects, where they in turn belong to the family of bristle tails (Thysanura) or rock jumpers (Machilidae).
Silverfish have six legs and no wings. The body of the little animal is covered with a “scale dress”, which has similarity with that of butterflies and is responsible for the typical shiny silver appearance of silverfish. Their external shape tapers from the head to the rear end of the body, giving them a fish-like appearance. There are two antennae on the head of the silverfish, while three appendages in the form of bristles can be seen at the rear end.
Silverfish are negatively phototactic both as larvae and imago (adult), meaning that they move away from light. They are nocturnal and remain hidden in their dark hiding places during the day. Therefore silverfish are not attracted by LEDs or other light bulbs.
Most of the time, we don’t see the silverfish because they are nocturnal and shy of light. So you have to catch them when you come home at night or go to the bathroom – and then turn on the light. As soon as you do this, they crawl into cracks, joints or behind baseboards and wallpaper.
How to Fight Silverfish
Actually, silverfish do not cause much harm and can be found in every household. They also do not transmit diseases. However, it becomes problematic when there are too many of the silvery insects in the apartment. Not only do we find this disgusting, it also indicates that the humidity is too high – and in the worst case, this can mean a mold infestation. They can also damage books and textiles.
The biggest problem, however, is not silverfish at all, but the humidity. If you lower the humidity, the silverfish also disappear.
Silverfish are active at ambient temperatures up to about 10°C. At temperatures above 35°C, silverfish die of heat exhaustion.
Bedrooms should be ventilated several times a day. Especially effective: Create a draft in several rooms including the bedroom. This is the quickest way to remove moist air from the room and bring in dry, cool air.
Lavender spray can also be helpful as a preventive measure. So-called sleep sprays, which you spray on your pillow, promise to help you fall asleep. They usually contain lavender essential oil, which has a calming effect. However, it has the nice side effect of deterring silverfish.
Important: Even if you have successfully gotten rid of the silverfish, they will come back if the cause of their infestation has not been eliminated. Therefore, regular airing is also very important as a preventive measure.