Fireflies, lightning bugs, glowworms. Whatever you call them, these beetles hail from the Lampyridae family, insects who, as larvae, can cast light and warn off potential predators. The chemical that causes their bioluminescence is bitter to the taste, so other animals will learn quickly to avoid them.
Some adults have evolved to use this light to attract mates—or prey, as the females of the Photuris genus do. These ladies use their light to mimic other firefly species, and draw in males who become their evening meal.
Fireflies live all around the globe, often near marshes or woodlands. In Connecticut, our most prevalent species is Photinus pyralis. Males float through the inky darkness of the night like lanterns, blinking once for three-tenths of a second around every five seconds. Females answer to males they like, flashing back to attract their notice. They mate, part, and find new partners. This goes on for about two or three weeks, when the females finally lay their eggs. The adults die before autumn settles in.
As larvae, fireflies are handy in the garden and in the yard. Their voracious appetites make them the bane of many of our garden pests. They live as larvae for around two years before they undergo complete metamorphosis, and live for one mating season as adults.
To help the fireflies in your area: reduce pesticide use, leave wild habitat alone, don’t be so hasty to clean up all the leaves every fall, and cut down on night lights. (Light pollution interferes with the signaling between males and females.)
If you’d like to take part in a community science program, check out Firefly Watch! www.massaudubon.org/get-involved/citizen-science/firefly-watch