Fireflies are more than a glowing bug that lights the summer nights, according to a local entomologist.
Dr. Karla Adesso directs the Nursery Research Center in McMinnville. Adesso said fireflies are a kind of beetle that produces a chemical reaction to make them glow. Adesso said some insects use chemicals or noises to communicate and reproduce, but fireflies communicate with their glow.
“They have sort of a blinking, you know, red light green light pattern of, ‘Here I am, come find me,'” Adesso said. “The males will flash a certain pattern and the females will flash back. And so, when they’re flying around, they can find each other.”
Adesso said fireflies depend on light to communicate, and studies show firefly populations are declining in cities due to an increase of artificial light at night. Adesso said the best place to find fireflies are natural places with little to no artificial light.
Adesso said fireflies are an underground predator as larvae.
“A lot of the problem insects you have in your lawn, or that you see around in the ground, [fireflies are] actually actively eating them,” Adesso said. “So slugs, snails, small little critters, earthworms. And so they help keep that environment in the soil in balance.”
Adesso said adult fireflies eat nectar or pollen.
Adesso said fireflies are in the middle of the food chain, and are eaten by small mammals, birds and, and other large insects. Adesso said the glowing chemicals in a firefly make them taste bad, so some predators will spit them out.
Adesso said fireflies cause no harm to humans, but people can have a big impact on them.
“As young, they’re living and feeding in the soil, and they actually do much better when we don’t rake our leaves up, or when we keep much down and keep the ground covered and moist,” Adesso said. “That’s why you don’t see as many in well-manicured yards as you do in the forest and wooded areas where there’s mulch and natural things in the soil.”
Adesso said firefly life cycles can last up to two years, and there are several different species in Tennessee.
