The Sad, Brutal Reality of the Beautiful Glowworms

I ventured deeper and deeper into the heart of a limestone cave in Waitomo, thankful for the lights illuminating the narrow passageway. Sticky fishing lines like diamond necklaces fell freely from stalactites, delicate they looked but deadly they were: a festooned trap for insect preys; the glowworms’ sustenance. My guide of Māori descent stopped Jolyn, my tour mate, and me in our tracks, before stealing away to switch off the lights. The sudden heft of the silence and blackness, which blotted from view my companions, weighed heavily on me. The zephyr kissing my cheeks was a cold touch.

And just when I was beginning to feel like the walls of suffocating darkness were hemming me in, soft mesmerising blue lights began to fill the face of the tunnel, like glittering stars revealed after the tearing of clouds. This dreamlike display of light feels like the work of an arcane spell, but in reality is a chemical reaction between luciferase, luciferin, adenosine triphosphate and oxygen.

Glowworms capable of bioluminescence are in their larva stage, which spans six to nine months. Their light ensnares not only the wistful gazes of human beings but also insects as big as cockroaches. “Go towards the light” takes on a new meaning, as preys like moths to a flame meet their ends as they become entangled on the sticky fishing lines.

But feed the glowworms must, for they do not do so when they metamorphose into pupae and adults. In fact, in their adult stage, they lose their mouths, living their few numbered days starving, bereft of food. They exist only to mate and reproduce, and pass on when their life’s work is done.

Photo credit: Felix Plakolb