The strategy supposedly prevents them from being burned to death or gobbled up.

These moths swarming in 2006 in Tudela, Spain, obviously missed the memo that artificial lights can be bad for them. (Alvaro Barrientos/AP)

Everyone knows that moths love light. But what you love can kill you, as proven by the millions of flying insects that immolate themselves on hot lights, or are gobbled up by predators in well-illuminated environments.

For that reason, some moths have evolved to avoid artificial lights, according to new research from Swiss zoologists. Researchers trekked around Basel collecting thousands of young, small ermine moths from dark areas (villages) and ones bathed in light pollution (cities). They then raised the bugs into adulthood and tested their reactions to light. The result: Moths descended from generations in heavily lit places tended to avoid human light, or as their study in Biology Letters phrases it, showed a “significant reduction in the flight-to-light behaviour.”

These altered instincts could be good and bad news for the insects, as well as organisms that depend on them, like plants in need of pollination. Here’s more from the study:

The reduced attraction to light sources of ‘city moths' may directly increase these individuals' survival and reproduction. We anticipate that it comes with a reduced mobility, which negatively affects foraging as well as colonization ability. As nocturnal insects are of eminent significance as pollinators and the primary food source of many vertebrates, an evolutionary change of the flight-to-light behaviour thereby potentially cascades across species interaction networks.

A small ermine moth. (F. Altermatt/University of Zurich)

About the Author

Most Popular

  1. a photo of a full parking lot with a double rainbow over it
    Transportation

    Parking Reform Will Save the City

    Cities that require builders to provide off-street parking trigger more traffic, sprawl, and housing unaffordability. But we can break the vicious cycle.   

  2. A woman looks straight at camera with others people and trees in background.
    Equity

    Why Pittsburgh Is the Worst City for Black Women, in 6 Charts

    Pittsburgh is the worst place for black women to live in for just about every indicator of livability, says the city’s Gender Equity Commission.

  3. Life

    Mapping the Changing Colors of Fall Across the U.S.

    Much of the country won’t see those vibrant oranges and reds until mid-October, which leaves plenty of time for leaf peepers to plan their autumn road trips.

  4. a map comparing the sizes of several cities
    Maps

    The Commuting Principle That Shaped Urban History

    From ancient Rome to modern Atlanta, the shape of cities has been defined by the technologies that allow commuters to get to work in about 30 minutes.

  5. a photo of a man at a bus stop in Miami
    Transportation

    Very Bad Bus Signs and How to Make Them Better

    Clear wayfinding displays can help bus riders feel more confident, and give a whole city’s public transportation system an air of greater authority.

×