Glow-worms

22 August 2019 | Posted in Charlotte Owen
Glow-worms
© Derek Middleton

By Charlotte Owen

WildCall Officer

Lampyris noctiluca. It sounds like a spell that could be uttered by a student at Hogwarts but this is the Latin name of one of our most magical creatures, the Glow-worm. If they really could be conjured into life by the wave of a wand the result would be an impressive constellation of glowing green lights, arcing through the air to illuminate the night. Sadly this mesmerising display would be disappointingly brief. Only the females glow, and while they can keep their little tail-lights on for hours at a time they don’t have wings and can’t fly. Rather than a magical cloud of floating Fireflies, the hapless Glow-worms would continue their trajectory and tumble down to earth in a glimmering heap. While this might have its uses, a simple Lumos charm would surely be more effective.

The Glow-worm’s glow has inspired countless fairy tales and reams of folklore but this seemingly-supernatural ability has a solid scientific explanation.  It’s a fascinating example of bioluminescence, the emission of light by a living organism.  This trait is much more common in the oceans, which are full of luminous marine creatures from algae to squid and deep sea dragonfish.  The Glow-worm is one of the few terrestrial beings to have mastered this power, which stems from a simple chemical reaction.  It begins with a measure of luciferin, a light-generating substance whose name derives from the Latin lucifer, meaning light-bringer.  Add a pinch of luciferase, an enzyme that will catalyse the reaction, and ensure a steady supply of oxygen before kick-starting the process with a jolt of metabolic energy.  Then – as if by magic – there is light.

Females use their luciferin-fuelled lanterns to attract a mate, and with only a few weeks to live there’s no time to waste.  An enchanting light show is the surest way to romance, so they climb as high as possible to secure a good vantage point before beginning their broadcast.  Male Glow-worms do have wings and they fly around in search of females, homing in on their glowing abdomens until they are lured into landing by the beacon that shines the brightest.  

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