The Dangers of Light Pollution on Insect Ecosystems
Urban astronomers and insomniacs aren’t the only ones affected by light pollution. New research shines a sickly-orange spotlight on the impact our streetlights may have on insect populations and biodiversity.
“Insects provide crucial services to humans, such as pollination and decomposition to organic matter,” researcher Thomas Davies told Discovery News. “We are facing an insect biodiversity crisis.”
Davies and his team, who are members of the University of Exeter’s Environment and Sustainability Institute, conducted an experiment using insect traps in Helston, Cornwall, UK. For three days and nights, they placed the traps near streetlights and measured them 30 minutes before sunrise and sunset.
The traps that were closest to streetlights picked up a significantly higher number of bugs, even during the day. By the end of the study, researchers found a total of 1,194 invertebrates representing 60 different insect species. Ants, beetles, woodlice and fleas were among the most common.
“These species are generally more mobile than others, making it more likely that they will encounter habitats that are lit to varying levels of brightness, providing them with the opportunity to make a selection of a preferred habitat,” Davies told Discovery News.
It’s no surprise that light attracts bugs, but Davies warned that the increase in artificial light is changing the insects’ migration and hunting patterns in ways that may disrupt larger ecosystems. Everything from birds to sea turtles to humans could be impacted as the insect communities gravitate toward more urban and suburban places.
Davies cited a different study that found that Triatoma dimidiate, an insect known for carrying an infectious disease called Chagas, was more likely to infest a building if that building was close to a streetlight.
“The range of effects of light pollution are really very diverse,” he said.
“So far, much of the research has shown that artificial light changes the behavior of individual species,” added John Hopkins, an adviser for Natural England. “These effects are very diverse and range, for example, from changes [in] mate locating success, migration and predation behaviors, among others.”
Hopkins hopes the new research will enable scientists to discover the precise effects that light pollution and insects have on an ecosystem. “Although invertebrates seem to be lowly life forms, in many ecosystems they have more impact than birds and mammals,” he said.
According to Discovery News, experts estimate that light pollution around the globe is increasing by 6% each year.
Photo credit: Sarah Cartwright (Creative Commons)