More data is needed to understand the insects in rural areas, researchers say
By Chloe Bennett
The annual summer show of twinkling fireflies is underway in parts of the Adirondacks. For many, the flashing beetles’ display is an essential part of the warm season, woven into outdoor evenings.
The future of fireflies in North America is uncertain, researchers say, as warming temperatures affect the insects’ population sizes. The Adirondacks could see a larger population of fireflies in the years ahead or experience summers with fewer nighttime light shows.
The Adirondack Explorer thanks its advertising partners. Become one of them.
A June study published in the journal “Science of the Total Environment” showed that climate change’s impact on fireflies is greater than previously thought. Researchers analyzed citizen science surveys from 2008 to 2016 to compare land use changes, pesticide use and soil conditions with long-term climatic patterns. Their findings were the first to show how warming measures up to past hypotheses on firefly loss.
“We previously knew there was something there, but now we know, holy crap, this is big,” said researcher Darin McNeil, assistant professor of forestry and natural resources at the University of Kentucky.
The climate connection
The research indicates that southern locations with drought could see fewer firefly populations in the coming years, but McNeil said northern parts with warmer winters and more flooding aren’t immune to the potential loss.
The Adirondack Explorer thanks its advertising partners. Become one of them.
As larvae, fireflies are soft-bodied and roam soil looking to snack on snails and other insects. Floods can wipe out the beetles in their early stages, which they remain in for up to two years. The bugs also require freezes and lengthy winters, McNeil said.
“If you think back to the winters that the Adirondacks had 20 to 30 years ago that were really cold for extended periods of time, I think that’s what fireflies in that region are probably going to be best adapted to,” he said.
Anecdotal evidence shows the park has already seen abundant firefly populations this summer. In Bolton, William Adamczak, who photographs night scenes, said his neighborhood seemingly has more flashing insects this year than last. “My kids make note of it every night as we try to go to bed,” he said.
On social media, people wrote of witnessing the beetles in places including Chestertown, Lake George, Lake Clear and Saranac Lake.
The Adirondack Explorer thanks its advertising partners. Become one of them.
Firefly climate migration
As North America warms, some of the more than 100 species of fireflies could migrate north and to higher elevations and reproduce there. Scientists say around half of the world’s plants and animals could be on the move to escape unsuitable conditions from climate change.
Many insects travel long distances seasonally, but fireflies could move to northern locales permanently for more satisfactory environments. With research suggesting the likelihood of climate migration, McNeil said fireflies are unlikely to be an exception.
The Adirondack Explorer thanks its advertising partners. Become one of them.
“There are some places, probably, that are very far north and may not have that many fireflies and that actually may experience a big increase in the amount of fireflies, which would be kind of cool for them in some regards,” he said. “But there are a lot of places, with either very low elevation (or)very far south, that may actually lose their firefly populations because they’re effectively migrating north.”
According to climate projections, the park could experience a temperature increase of more than 6 degrees by the 2060s. More rain is also expected as warmer air leads to more precipitation. But the region could provide higher quality habitats with colder winters and wetter springs than southern sites with drought.
Citizen scientists wanted
The researchers used data from the now-defunct Firefly Watch program, which Mass Audubon operated in Massachusetts. Now, firefly surveyors are encouraged to participate in the nonprofit The Xerces Society’s Firefly Atlas.
Participants in Firefly Watch recorded surveys from wherever they were, even in the absence of fireflies. “Maybe you count 10, maybe you count 100,” McNeil said. “But importantly, maybe you count zero and you can record that information, and those zeros are so important.”
Data from programs like Firefly Watch, iNaturalist and eBird are rich in observed data, but most participants are based in urban areas. Data from the firefly survey was sparse in the Adirondacks, according to the study, likely because of its rural setting.
McNeil said people in the North Country interested in conservation can help by contributing to citizen science projects focused on fireflies. Typically in the Adirondacks, fireflies, also known as lightning bugs, show up in late June to early July, putting on a light show that spans a few weeks.
People concerned with the loss of flashing summer displays can also take steps in their yards. Minimizing pesticide use is one way, along with “leaving your leaves in and around your garden over the winter time to provide those fireflies some overwinter protection,” McNeil said. “This is especially important when we have a mild winter with less snow.”
Photo at top: Fireflies in the Grafton Lakes State Park in Rensselaer County. Photo by John Bulmer
Leave a Reply