Why are insects constantly buzzing around lamps? Researchers have probably solved the puzzle

Artificial light influences the flight orientation of insects. This could explain why light at night attracts moths and other insects, an international research team reported in a new study.

The fact that flying insects swarm around lights at night is so well known that it inspired the expression “being attracted to something like moths to a light,” as researchers from the US, Britain and Costa Rica explained in the article published on Tuesday. wrote a study published in the journal “Nature Communications.”

However, the reason for this phenomenon remains unclear. In previous research, among many other theories, it was assumed that insects interpret artificial light as an escape route or that they are blinded by the light source.

Only new camera technology has made it possible to film the insects at night clearly enough to see what is really happening, the researchers said. For the new research, they recorded the flight of various insects, such as moths, dragonflies and flies, under different lighting conditions using high-speed infrared cameras.

This showed that the insects did not go directly to the light, but instead turned their backs to the lamp and flew circles around it. In natural light, this response makes sense for insects, as the research shows. They turn their backs to the sun or moon and can therefore maintain a stable flight path.

However, artificial light sources such as lamps ensure that the insects continuously correct their flight path. They eventually fly around it in circles with a round lamp. According to the research, the insects are mainly caught. When light comes from the ground, the insects turn completely on their backs and sometimes fall, the research showed.

“This posterior alignment is sufficient to produce the apparently erratic trajectories of insects near light, and is the most plausible model for why flying insects congregate under artificial light,” the authors wrote. (dabbing/sda)