Sharing the Magic of Fireflies with Future Generations

Heather Raithby Doyle
2 hours ago
3 min read

by Heather Raithby Doyle

Fireflies need a few simple things from us: rotting leaves or logs, water or damp areas, darkness, and some long grasses to hang out on. In exchange, fireflies show us a truly magical sight: their glowing specks of light darting and dancing in the night’s darkness. It is the stuff of fairytales.

Ontario has more than 20 species of fireflies. In fact, fireflies are present in every continent except Antarctica. They face threats everywhere - dying from lack of habitat, bright lights, and pesticide and lawn care chemicals. As native plant gardeners, we can help.

This is a big dipper firefly (Photinus pyralis). commonly found in Ontario, particularly in the southwestern part of the province in broadleaf Carolinian forests. These fireflies are most active in the late spring and summer months. Firefly photo: iNaturalist , by dirtrdevacuator — **This is a big dipper firefly (Photinus pyralis).** **commonly found in Ontario, particularly in the southwestern part of the province in broadleaf Carolinian forests**. These fireflies are most active in the late spring and summer months. Firefly photo: iNaturalist , by dirtrdevacuator

Despite the name, fireflies are actually soft-bodied beetles. They may not attract your attention during the day. But at night these same plain bugs create their own light with a chemical reaction involving oxygen, the chemical luciferin, and an activator luciferase. Male fireflies blink in unique patterns with hopes of attracting a mate, who will flash back at him. In a few places, like the Great Smoky Mountains in Tennessee, fireflies blink in synchronicity.

Fireflies in some places like Gatlinburg, Tennessee blink in synchronicity. Photo: IG @gettinviggy

Fireflies have a two to three year lifespan which is why human’s habit of scouring the garden of fallen leaves is so harmful. After mating, a female firefly lays her eggs in leaf litter or rotting wood. Three weeks later the larvae emerge. In Canada, the larvae retreat and remain inactive underground for the winter. The larvae glow, a chemical signal to would-be predators signaling “I do not taste good!”

Larvae will feast on snails, slugs and worms, especially in damp soil, leaf litter, and marshy areas. They are voracious eaters of many creatures we would consider garden pests. When fully grown, the larvae pupate underground or in rotting wood, a one to three week process. Once hatched, most firefly adults do not eat, instead investing their energy in finding a mate and reproducing.

Despite our fascination, there is much scientists have yet to find out about fireflies. What we do know is that we need to act, so we can share the enchantment of fireflies with upcoming generations.

Here are few things we can do:

Leave leaf litter and incorporate logs in your garden
Encourage wet areas as fireflies feast on the insects that live there
Have a section in your garden with long grasses so females can find their mates, and not get trampled on, or killed by lawnmowers
Forgo lawn chemicals and pesticides, both are toxic to fireflies through exposure and diet
Turn off your lights at night. Bright lights interfere with their vision and chance of finding a mate
Plant native trees which provide both a barrier from human light, and produces leaf litter for larvae
Register for the Firefly Atlas, a citizen science initiative that monitors firefly poplualations.