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City moths develop smaller wings to survive light pollution

Moths fluttering around streetlamps are a familiar, if eerie, urban sight. But the bright lights of our cities may be doing more than attracting these insects — they might be changing them. Scientists from Belgium and Switzerland have discovered something peculiar about city-dwelling moths: they seem to have smaller wings than their rural cousins.

What’s more, they’re not as easily lured into the blinding glare of artificial lights. Researchers believe it could be an adaptation to survive the challenges of brightly lit cities.

Impact of light pollution on city moths

Light pollution, a constant companion of cities, has a devastating impact on moths and the ecosystem they support. Moths use the moon and stars to navigate. However, bright city lights confuse them, causing problems with feeding and mating, which puts their entire population at risk.

Artificial light also makes moths easy targets for predators since they are no longer hidden by the darkness of night. This increased hunting further damages moth populations and throws off the balance of the entire ecosystem.

Light pollution also disrupts moths’ internal clocks, which impacts their hormones and how they behave. This can affect their feeding, mating, and migration patterns. These problems further reduce moth populations and serve as a reminder of how light pollution hurts the environment.

Urban vs rural moth

If a moth lives in the countryside, the night sky is their map. But in the city, it’s a confusing mess of streetlights, billboards, and porch lamps. This is where the shrinking wings come in.

Urban moths, with their smaller wings, were less likely to be drawn towards artificial lights. This change may be an evolutionary response to the challenges of city life.

Scientists believe smaller wings might make urban moths more agile. This increased agility could help them avoid the distracting artificial lights and better evade predators. Smaller wings might also help them more efficiently find food in the fragmented city environment.

Other challenges faced by city moths

City moths face a maze of challenges beyond the problem of light pollution. The city is a harsh landscape of concrete, metal, and limited plant life – a far cry from the natural world they evolved to survive in. This presents them with unique difficulties that affect their ability to survive.

Roads, buildings, and other parts of cities break up natural areas, leaving moths with smaller, disconnected patches of green space. This makes it harder for them to find mates, food, and places to lay eggs, which drastically disrupts their life cycle and lowers their population.

Moreover, the “heat island” effect, where cities are much warmer than rural areas, is another challenge. Moths, like many insects, depend on their surroundings to control their body temperature. Hot city temperatures can disrupt their body functions, which affects how well they grow, reproduce, and survive.

Importance of conserving moths

Saving moths is much more than just protecting another kind of insect. It’s essential to keep our ecosystems healthy and balanced. Moths may not be as well-known as butterflies, but they play a vital role in the natural world that benefits both wild areas and places humans live.

Moths pollinate plants, especially ones that bloom at night. They help fertilize a wide variety of plants, including some we use for food, medicine, and clothing. Fewer moths mean these plants wouldn’t reproduce as well, leading to less food for people and animals and, ultimately, a loss of diverse species.

Protecting moths means protecting the services they provide to the environment. Reducing light pollution, saving natural habitats, and promoting a variety of species are some ways we can help ensure moths thrive, along with everything else they support.

Study insights

The mystery of city moths highlights the incredible persistence of evolution, even within our concrete and brightly lit modern world. Could their smaller wings be a survival strategy against artificial light? Only time and further research will reveal the answers.

Perhaps the next time you see a moth fluttering by, you’ll pause to consider the incredible adaptations it might be developing to survive in our human-shaped environment.

The study is published in Biology Letters.


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