Long Island fireflies on the decline, but advocates say there are ways to help protect, attract them

Amid a neighborhood of perfectly manicured yards and yellow pesticide signs, stands Leonard Green and Nancy Erber’s East Hampton home, surrounded by native woodland and a mixed meadow designed to provide an ideal habitat for Long Island's elusive fireflies.

The couple, who serve on the board of Rewild Long Island and cofounded ChangeHampton, advocate for sustainable landscaping practices and are involved in pollinator and firefly restoration efforts.

"Having grown up on Long Island, chasing and looking at fireflies was one of my favorite summertime activities. I just don’t see as many as I have in the past," said Green, 75.

Erber, 73, recalled similar memories growing up in Queens and said she finds herself wondering where the fireflies have gone every time summer rolls around.

"We used to love seeing fireflies even in the city, now I only see one or two," she said.

Climate change, habitat loss, light pollution and harmful landscaping practices make it difficult for fireflies to thrive and reproduce, contributing to a worldwide lightning bug decline, according to experts.

Threats on Long Island such as sea level rise, rapid development and the public's desire to have manicured lawns that use pesticides and lack natural places for fireflies to survive have pushed these and other species away in recent years. But experts are studying ways to document firefly species, help them thrive and educate the public about how to protect these creatures that once were so much more plentiful.

"We have a lawn culture that is simply not good for the environment ... We try to help people understand how beautiful working with environmentally sustainable landscaping can be and bring back charismatic and iconic insects like fireflies," Green said.

Finding the fireflies

There are more than 170 diverse firefly species in the United States and Canada, according to Katie Hietala-Henschell, a zoologist at the New York Natural Heritage Program (NYNHP). 

The NYNHP collects data on rare animals and plants in the state. The organization is more than halfway through its three-year "Dark Skies for Fireflies" study, which aims to find out which species are present in New York and how best to protect and manage the rare and threatened ones. 

New York is home to 40 recognized species facing a variety of threats, according to Hietala-Henschell. She said 12% of them are threatened with extinction or are species of conservation concern, while 33% have been assessed as data deficient or have not been evaluated due to lack of available information.

Richard Joyce, an endangered species conservation biologist at the Xerces Society for Invertebrate Conservation, has found records of 10 species on Long Island. The Xerces Society is an international nonprofit that helped form a specialist group to identify and conserve threatened firefly species.

Half of the species, including the common eastern firefly or big dipper, can be found in backyards and public parks. These fireflies are more impacted by light pollution and landscaping practices, said Joyce.

"There are ways for humans and fireflies to coexist, but the way people interact with the landscape around them has a big effect on how those fireflies persist," said Joyce.

Two of the 10 can be found in Long Island’s wetlands and are of special concern due to habitat loss, said Hietala-Henschell.

Those that live in salt marshes and other coastal wetlands must cope with rapid sea level rise, climate change and coastal development.

The remaining three species live in forests.

"Long Island’s a great place to live, and it’s been developed because everyone wants to live on the beach, but fireflies just can’t keep up with the changing landscape," Hietala-Henschell said.

But there is reason for hope.

The NYNHP recently detected two species not previously known to be found in the state, one of which was found in Connetquot River State Park Preserve in Islip.

"New York has a really high diversity of fireflies. We’re pretty lucky. We should try to protect them before it’s too late. Once a species becomes extinct, it’s really not coming back," Hietala-Henschell said.

Less light, more natural landscaping

Joyce said fireflies could possibly show up in a yard if the homeowner takes steps to attract them, such as reducing light pollution.

Fireflies use light to communicate with one another and find mates. Hietala-Henschell said research has shown that fireflies can’t see one another if it’s too bright outside and stop flashing or flash less out of frustration.

Hietala-Henschell and her colleagues did a survey at Captree State Park on the South Shore in 2023 and saw an abundance of fireflies. When the group returned the following year, she said there were no fireflies in sight, likely due to an influx of light for construction.

She acknowledged that light pollution will always be present in highly developed areas like Long Island. To minimize its impact, she recommended planting trees to block light, using shields, closing curtains at night and transitioning to motion sensor lights so they aren’t on all the time.

"Light pollution is the best pollution because it’s so easy to fix," she said.

Joyce said residents should also grow native plants, let grass grow, leave fallen leaves where they are and avoid pesticide use, as Green and Erber have. In addition to attracting more fireflies to their property, the couple said they’ve also seen more birds, butterflies and even box turtles.

Fireflies live on the ground during their larval stage, which is the longest part of their lives, according to Joyce. Hietala-Henschell said these larvae are an important link in the food chain and vital to a healthy ecosystem. Firefly larvae eat soft-bodied invertebrates such as worms and snails and serve as prey for spiders and other insects, which in turn feed larger animals including frogs and birds.

Green argued there can be a balance between the perfectly manicured yard and what some may call unkempt. He recommended choosing sections to pile leaf litter and grow native plants, while maintaining others in their preferred fashion.

He also recommended using mosquito dunks to control mosquito larvae instead of killing all the insects on their property with pesticides and other chemicals.

"Our properties are part of larger ecological systems that don’t understand the idea of property lines. What we do on our properties matters," Green said.

Through the Firefly Atlas, Joyce said the Xerces foundation is trying to build a community of those interested in firefly conservation and encourage people to get familiar with the fireflies in their area.

The platform, which aims to track and help conserve threatened and data-deficient species in North America, teaches people how to survey the threatened species in their area and submit observational data.

"Sometimes I like to compare fireflies to birds," Joyce said. "The world of bird conservation has really benefited from there being lots of nonprofessionals who like to do bird watching as a hobby and put data into community science platforms."