Keepers of the Night: Why Moths Deserve a Second Look

Ahead of National Moth Week, a Rutgers postdoctoral researcher explains how the winged insects play a bigger role in nature than many realize

Spend a summer afternoon in a garden and you're likely to notice butterflies fluttering among the flowers.

Come back after dark and you'll discover a different world, one filled with moths.

Butterflies and moths are close relatives, but while butterflies often capture people's attention during the day, many moths go unnoticed because they're active after dark, said Yahel Ben-Zvi, a postdoctoral researcher with the Department of Entomology at the Rutgers School of Environmental and Biological Sciences who studies beneficial insects and their role in agricultural ecosystems.

"Many moths are just as large, colorful and beautiful as butterflies," Ben-Zvi said. "The difference is that most people don't see them as much because they're active at night."

During the day, many moths hide in plain sight. Some resemble leaves. Others look so much like tree bark that people often walk right past them without realizing they're there, Ben-Zvi said.

National Moth Week, held this year from July 18 through July 26, offers people a chance to experience that hidden world for themselves, including a July 23 celebration at the American Museum of Natural History that Ben-Zvi helped organize.

Moths are also often associated with holes in sweaters and other fabrics, but that reputation is largely undeserved.

"In reality, only about two species are considered clothes pests," Ben-Zvi said. "And it's actually their caterpillars, not the adult moths, that feed on fabrics."

Life after dark has driven some remarkable adaptations.

Because many species can't rely on sight to find mates, male moths often have large, feathery antennae capable of detecting female pheromones from long distances, Ben-Zvi said.

They also play a crucial role in healthy ecosystems. They are important pollinators, particularly for flowers that bloom at night, Ben-Zvi said.

In addition, they provide food for birds, bats and other animals. Some plants depend almost entirely on moths for pollination. The yucca moth, for example, is the only pollinator of the yucca plant.

But not all moths wait for the sun to set.

Hummingbird clearwing moths and certain hawkmoths are active during the day and are frequent visitors to flower beds, including those at Rutgers Gardens in New Brunswick, N.J., where they help pollinate flowering plants, Ben-Zvi said.

For many people, porch lights are where they're most likely to encounter moths, watching them frantically circle the light. That familiar sight has helped shape one of the biggest misconceptions about moths.

"When flying at night, moths use the light of the moon and stars to help them navigate," Ben-Zvi said. "Artificial lights confuse those navigational cues, which is why they often end up flying toward porch lights and streetlights."

Some of Ben-Zvi's favorite moths can be found in New Jersey, including the luna moth.

Its long trailing tails can confuse the echolocation that bats use to find prey, helping the moth escape predators, Ben-Zvi said.

"Watching luna moths fly almost feels like being surrounded by fairies," Ben-Zvi said.

As with many insects, moth populations are declining, with habitat loss, climate change, light pollution and changing land use among the factors that scientists say are contributing to the trend, Ben-Zvi said.

People can help by planting native vegetation, especially flowers that bloom toward dusk, reducing unnecessary outdoor lighting and limiting pesticide use, he said.

National Moth Week has Rutgers roots. It began in 2012 as a local celebration in East Brunswick, founded by Rutgers alumnus David Moskowitz, who earned his doctoral degree in entomology from the School of Environmental and Biological Sciences, and Liti Haramaty, a marine sciences researcher in the Rutgers' Department of Marine and Coastal Sciences, before expanding into an international citizen science initiative.

Ben-Zvi, who attended National Moth Week events while growing up in East Brunswick, N.J., earned both his undergraduate and doctoral degrees from the Rutgers School of Environmental and Biological Sciences.

In 2022, Ben-Zvi became National Moth Week's first U.S. coordinator and today is one of 39 country coordinators helping organize events in the United States.

But National Moth Week is about more than moths, he said. Through local mothing events, museum programs and other outreach, Ben-Zvi hopes to bring researchers and the public together through a shared curiosity about the natural world.

"Scientists are part of the public, and people in the public can love science," he said.