Who is glowing in the woodland darkness this fall?
Firefly larvae, also known as glow-worms, are bioluminescing! Most adult fireflies spend a few weeks in early summer flashing courtship signals and then lay their eggs. The larvae emerge in late summer, live through the winter, and pupate in the spring (or even the next spring). There are species of winter fireflies where adults don’t light up and are active in the day during thaws.
All firefly larvae can bioluminesce – even when adults cannot. Scientists think the glow evolved as a way to signal to predators that they are toxic. Firefly larvae live in soil and leaf litter, where warning coloration wouldn’t be visible. They inject neurotoxins to paralyze their prey (such as earthworms, slugs and snails) then secrete digestive enzymes to liquify and suck up their meal.
On moonless nights in dark, damp places, be on the lookout for firefly larvae’s faint green glow!
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