In the summer of 2019, while joking about the oaks of the apocalypse still seemed refreshing and fun, an endless flock of weeds landed on the Las Vegas Strip.
These insects were not biters or crop killers. But for weeks, every evening after sunset, their flapping wings filled the sky beam to shine from the pyramids of the Luxor Casino, and their dead exoskeleton wet the pavements. The news media speculated that the outbreak could be attributed to a wet winter that allowed more eggs to lay, and the city’s artificial lights, which tempted her to flame in grass-thatch-like greed.
A new analysis confirms the link for city lights – with worrisome effects for locusts. Elske Tylens, an insect ecologist at the University of Oklahoma, found that on July 26, 2019, the peak night of the invasion, some 46 million locusts took wings and then climbed the brightest parts of the city.
“It’s really hard to wrap your mind around that section,” she said. “We’re getting more hay in the air in a single day, like you come to Vegas to get humans.
Visitors, of course, already knew that Las Vegas cranked up its wattage at night. But some of that glow escapes directly into space, where satellites measure it as the brightest city on the planet by a wide margin. The rest of that light, flowing into the atmosphere, forms a glowing dome that was recently measured in Great Basin National Park in Nevada, US, 200 miles away.
Insect ecologists, for their part, have spent years studying how individual lamps and night-time insects can have a silent siren call, luring them to their deaths. But inspired by the coverage of the 2019 Vegas locust invasion, Dr. Tielens and his colleagues saw an opportunity to hunt for broader patterns. They found that the rotating clouds of locusts were also visible in weather radar data. They then looked at those radar movement patterns with different maps of the city’s flora and its night light.
His study published today in the biology paper suggested daily commutes. Before dusk, weeds began to spread over a wide area, gathering near the vegetation. But in the daylight, they took to the skies. They then traveled dozens of miles away, traveling not only toward individual bright points, as previous research has documented, but towards the brightest regions of the Vegas sky.
“This is a really exciting paper,” said Brett Seimoure, an ecologist at Washington University in St. Louis, who did not participate in the research. “We do not yet have evidence with this paper, that the light dome is guiding pests.”
Insect ecologists were already concerned that individual insect populations were shrinking around the world, perhaps due to pesticide use, habitat loss, pollution, climate change and artificial light at night. Dr. In Tillanes’s study, she says, it is not estimated how many locusts died, or how a night trip in the heart of Vegas could affect the next generation of locusts. But it shows that artificial light can affect insects on a regional scale, and that on July 26, 2019, the city’s shimmer called for 30 metric tons of crisp, aerial biomass, which would otherwise spread to a much larger ecosystem Will be
“It’s scary from an ecological point of view,” Dr. Semure said. “It is also awful for a lot of people in Las Vegas, all these mowers to get around. Although I think it would be great to see. “