Media release
From: Springer NatureInvestigating why flying insects gather at artificial light
Artificial light may impair insects' ability to correctly orient themselves to the horizon, suggests research published in Nature Communications. The findings may help us to understand why flying insects gather around artificial lights.
Artificial light has been known to attract flying insects for many years, with written records from the Roman Empire describing the use of light to trap insects. However, the reason behind the phenomenon is still unclear. Previous research has proposed that insects may be interpreting artificial light as an escape route, or that insects are blinded by the light source, in addition to numerous other theories.
Samuel Fabian, Yash Sondhi and colleagues used high speed infrared cameras to track insects’ three-dimensional flight, both in their natural environment and in laboratory conditions. They examined a range of insects — including moths, dragonflies, fruit flies, and hawkmoths — under a range of light conditions, including point and diffuse UV light sources. They found that insects present a “dorsal light response”, correcting their flight course so that their back is facing towards the light source. With natural light sources such as the sun, this response causes the insect to hold a steady flight path correctly oriented with their horizon. However, artificial light causes erratic and continual correction of the flight path, causing insect vertigo and producing what we see as an attraction to artificial light, the authors suggest.
The authors conclude that further work examining the long-distance impacts of artificial light is necessary, and that we can improve insect habitats by reducing unnecessary artificial lighting at night.
