AgCenter entomologists try to bring back fireflies

Around the country, firefly populations have reached historically low numbers. At one time, they lit up the night with their blinking mating calls. Today, these luminescent insects are quietly disappearing, as their habitats and food supply have been greatly impacted.
In Louisiana, pesticides, habitat loss in the form of urban development, invasive insects, lack of maintaining leaf litter beds and light pollution have been the major causes of the decline in firefly population, said LSU AgCenter entomologist Aaron Ashbrook.
The town of Jean Lafitte reached out to Ashbrook and fellow AgCenter entomologist Christine Gambino to help to reestablish firefly populations that were once so prevalent in its Wetland Trace boardwalk trail.
The situation at Wetland Trace seemed dire. The then mayor of the town, Tim Kerner Jr., gave Ashbrook and Gambino a tour of the area, telling stories of how he remembered seeing fireflies as a kid and how they have disappeared since.
The entomologists took insect samples of the area and found no signs of fireflies on the trace. While their results do not guarantee that fireflies have completely disappeared from the area, their findings underscored the need to improve conditions for fireflies.
The team came up with a few steps to attempt to restore the area. To begin, they created artificial areas that fireflies could live and reproduce in, called leaf litters, that were deposited in a wooded swampy area.
“The habitat was placed here because fireflies have two different types of habitats,” Gambino said. “Some prefer semi-aquatic, and others prefer wetland prairies.”
The entomologists also worked to create a habitat for the food that most fireflies eat: snails and slugs. They accomplished this by working with botanists from the Louisiana Department of Wildlife and Fisheries. They brought in native plants that would establish in the area to mimic the environment fireflies would have lived in before human encroachment.
“We were targeting a wetlands prairie habitat, so we established a 1,500-square-foot area, planted 375 native plants, and we also had a donation of 50 Louisiana irises from the Iris Conservation Society of Louisiana,” Ashbrook said.
The native plants were grown by a local native plant nursey, Sweet Fern Landscapes, and transported to Jean Lafitte. Along with native plants that could bring back fireflies, the entomologist team also included plants that attract pollinators like monarch butterflies and bees.
Gambino and Ashbrook were assisted by an LSU College of Agriculture undergraduate student, Briana Carpenter, who helped with habitat planning.
These projects were established on Nov. 22, with help from the city of Jean Lafitte, the LSU AgCenter, and local volunteers. 
This collaborative project was also supported by the efforts of Tim Kerner Jr., Councilman District 1, Tim Kerner Sr., Louisiana House Representative, Yvette Crain, mayor of Jean Lafitte, and Jennifer Van Vrancken, Council at Large.
“This is somewhat experimental,” Ashbrook said. “We’re not sure if it will work. We’re really calling it more of a habitat restoration with the hope that we will bring back fireflies. But, of course, the original goal was to bring back fireflies.”
Now, the team is looking to do a similar project at the LSU AgCenter Botanic Gardens at Burden in Baton Rouge. Carpenter will be conducting surveys for the insects at the location and implementing different habitat designs at the Botanic Gardens.
“We have reports from some of the staff there that fireflies are present on site, but we did not find them in the initial surveys,” Ashbrook said. “The plan is to do something similar but with a little bit more habitat variation.”
In addition to creating habitats, the team is considering creating barriers to block out light pollution, different light usage or shutters to redirect light at night. Because fireflies use patterned flashes of light to lure mates, outdoor night lights that create light pollution can eliminate a population in one season through mating disruption.