One of the main reasons to visit the Waitomo Caves is to see the beautiful lights created by glowworms on the walls and roof of the caves. These spectacular light displays are all thanks to a tiny little insect. Let’s find out more about the glowworms of Waitomo Caves.
The glowworms in the Waitomo and Ruakuri caves are the larvae (grubs) of a species of gnat called Arachnocampa luminosa, which is unique to New Zealand. Their scientific name means ‘spiderlike (arachno) ‘larva’ (campa) ‘that produce light’ (luminosa).
Glowworms spend most of their life as larvae and can grow to the size of a matchstick. You might want to know what a glowworm looks like without its light on, but you’d probably be disappointed if you saw one, because it looks a lot like a maggot. It’s better just to enjoy the beautiful effect they create inside the Waitomo Caves.
The pretty light that you see when you visit Waitomo Caves comes from the glowworm’s tail, which is bioluminescent. This means that the chemicals it secretes react with the oxygen in the air to create light. The glowworm’s prey is attracted to the light and gets trapped by the sticky threads the glowworm spins from the roof of the cave. This is why their scientific name includes ‘spiderlike’ – because they catch their food like spiders do, just with an added light show!
Glowworms catch and eat small flying insects, like moths and flies.
The Waitomo Caves are dark, damp and sheltered, creating an ideal environment for glowworms to live in. The darkness ensures the glowworms’ lights can be seen, and there’s no wind to dry out or blow away their sticky threads. The Waitomo River flows through the caves, bringing them plenty of insects to catch. It’s the perfect home for the Waitomo Caves glowworms.
The conditions inside the Waitomo Glowworm Caves are carefully monitored to make sure the glowworms are being looked after. Flash photography isn’t good for the insects, so no photos are allowed inside the caves. Luckily the spellbinding sight of a twinkling galaxy of lights overhead is so unforgettable, you’ll remember it without any pictures!