The key point of the article "Why flying insects gather at artificial light" published in Nature Communications is the exploration and explanation of why insects are attracted to artificial light sources. The study focuses on the phenomenon of light attraction in insects, using both field data and laboratory experiments to understand the behavior of insects around artificial light.
The researchers found that insects do not fly directly towards artificial light sources but rather exhibit flight patterns that are orthogonal to the light source. This behavior refutes the idea that insects are attracted to light as an escape response. Additionally, the study contradicts the notion that the confusion of a celestial compass by the light is responsible for the insects' behavior. The researchers also tested the hypothesis that heat radiation from the light source is attractive to insects, but found that LED lighting, which provides negligible infrared radiation, still entraps insects.
The article concludes that the dorsal-light-response, a basal sensory mechanism, is the most parsimonious explanation for insect light entrapment. This mechanism explains the high prevalence of light attraction across a wide range of insects, both diurnal and nocturnal. The study provides a detailed analysis of insect flight trajectories around light sources, using motion-capture data and field observations to support their findings. The researchers also made their code and data available for replication, further contributing to the understanding of insect behavior in relation to artificial light sources.
What is the dorsal-light-response and how does it explain insect behavior around light sources ?
The dorsal-light-response (DLR) is an innate behavior in insects that helps them orient themselves in space by tilting their backs (dorsal side) towards the brightest visual area, typically the sky or moon. This behavior is crucial for insects to determine which way is up, essential for maintaining proper flight attitude and control. However, when insects encounter artificial light sources, this response can backfire, causing them to fly in circles or loops instead of straight towards the light. This phenomenon, known as the dorsal-light-response, is the reason why insects are attracted to artificial lights at night. [Liz Kimbrough 2024]