Fireflies — also called lightning bugs, big dippers, and moon bugs— are known for their trademark glow.
In addition to lighting up the evening sky with a twinkling luminescence, fireflies are hugely beneficial to the environment.
They feed on plant-destroying garden pests. They don’t bite or sting. And unlike most insects, they don’t carry diseases.
Now, the nocturnal beetle — yes, beetle! — is finally getting global attention.
As a child, Jusoh grew up along the coast of Peninsular Malaysia and traveled to a mangrove estuary to see countless fireflies — known as “kelip-kelip” in Malay — “flashing in almost perfect unison.”
From that day on, Jusoh became entranced by the small, twinkling insects and dedicated her scientific career to studying and preserving them.
Every firefly species is unique.
“There are more than 2,000 firefly species that we know of, and they live all around the world,” Jusoh said in her Talk. “They are found in every continent, except for Antarctica.”
Although most fireflies have wings and emit light, Jusoh said that each species has a “unique light pattern.”
“The light is produced by special organs under the abdomen. … Some glow continuously, while others emit discrete flashing patterns, almost like a secret code,” Jusoh said in her Talk.
Although the lights have a near-magical quality to them, Jusoh explained that fireflies are “so much more than pretty lights.”
Firefly loss points to bigger issues in environmental health.
“They are an essential part of a healthy ecosystem. The lifecycle of fireflies keeps the ecosystem balanced. Each firefly, in each indicative life stage, has specific needs for habitat to thrive,” Jusoh explained.
Jusoh said that dwindling firefly populations are huge indicators of an ecosystem in decline.
“In a mangrove forest, when you see a population of fireflies decreasing, that could be due to water quality degradation, which can be a sign of a collapsing food chain,” Jusoh said in her Talk. “Why? Because firefly larvae eat snails, and snails need good water quality to thrive.”
In a way, fireflies are a “canary in a coal mine” when it comes to signaling a habitat in distress. If fireflies are dying off, that means that other species in that same habitat are also declining, and the ecosystem is unhealthy.
Fireflies need our help.
In addition to their ability to signal broader systemic issues in ecosystems around the world, fireflies play a unique role as both predator and prey in their local food chain.
They feed on soft-bodied invertebrates like slugs, snails, and earthworms, while also providing food sources for critical species like birds, spiders, and frogs. In short, fireflies are crucial to food-web stability.
Unfortunately, firefly populations are threatened by climate change and an abundance of artificial light pollution, which can “disorient, repel, or blind them.”
According to the Washington Post, nearly 1 in 3 firefly species in the United States and Canada may be threatened with extinction.
“This is bad for the Earth [and] humans too,” Jusoh warned. “It is a sign of overdevelopment that can induce climate effects such as flood and drought.”
There are ways to make a difference for fireflies.
Fortunately, there are a number of eco-friendly actions you can take to help preserve fireflies in your own backyard.
First, avoid using pesticides and chemical fertilizers in your yard. Although many pesticides promise an easy weed-killing solution for your lawn, they’ve also proven to be toxic to other organisms like birds, plants, and our glowing beetle friends.
Other action steps include planting native trees and grasses and cutting down on mowing, which helps preserve pollinators like bees as well.
You can also help by reducing excessive use of artificial lights, which endanger fireflies and make it more difficult for them to reproduce. Clicking off artificial lights at night also helps protect birds, owls, and other nocturnal wildlife that rely on moonlight and starlight for navigation, migration, and hunting.
Lastly, you can help fireflies and cut down on your chore list at the same time by not raking leaves. Firefly larvae live in leaf piles along with butterflies, chipmunks, turtles, toads, and more. Raking or blowing leaves could disrupt a firefly’s lifecycle before it even begins.
Countless fireflies are still waiting to be discovered.
With population decrease on the rise, Jusoh has become fiercely protective of fireflies and the “fascinating mysteries” they present.
In Singapore, Jusoh discovered the first new luminescent firefly species — the Luciola Singapora — in the region in over a century.
On another occasion, while exploring and collecting samples of new firefly colonies, Jusoh and her team found themselves surrounded by a bask of crocodiles blinking up at them out of the dark and narrowly escaped to safety.
No matter where her self-made mission takes her, Jusoh hopes to identify and conserve firefly species around the world.
Jusoh said: “Imagine how many more remarkable firefly species are waiting to be found. … Fireflies need your help before they flash that one last time.’”
Header image courtesy of Erin Lubin / TED