If you’re planning your road trip around New Zealand, you’ve probably noticed that there are these things called glowworm caves that are seemingly on every sample itinerary. Depending on where you’re from, glow worms may seem like a totally foreign (and potentially spooky) concept, but they’re actually very interesting creatures that can create the most magical setting. Here are some glowworm facts to help prepare you for your tour that will totally blow your mind.
What are glowworms?
Glowworms are not actually worms, but the larvae of fungus gnats, an insect that looks like a mosquito. There are two types of fungus gnats – those that feed on fungi like mushrooms, and those that are carnivorous and feed on other smaller insects. The glowworms in New Zealand and Australia are the larvae of the carnivorous fungus gnats.
Glowworm fact: The term ‘glow worm’ is actually a misnomer as these creatures aren’t worms – they’re larvae.
Why do glowworms glow?
Glowworms are bioluminescent, meaning they produce and emit light naturally from an organ near their tails that is similar to a human kidney. The bioluminescence is created through a reaction of an enzyme called luciferase and a variety of other chemicals that cause this natural, blue-green glow.
Beyond being pretty to look at, the bioluminescent glow is also used to attract prey. Smaller insects and flies are drawn to the light and fly towards it.
Glowworm fact: Glowworms glow because the chemicals and enzymes from their bodies are reacting with oxygen in the air to create light. There is a sac surrounding the light organ that provides oxygen and helps concentrate the reflection of the light.
What do glowworms eat?
While glowworms are rather small, about the size of a matchstick, they prey on even smaller insects such as mayflies, midges, moths and flies. To capture their food, glowworms build a network of silk threads that hang vertically from their habitat that are covered in a sticky mucus. As the insects are drawn to their glowing bioluminescent light, they fly toward it and into the sticky silk maze, where they get stuck for glowworms to eat – similar to how spiders capture their prey in webs.
Glowworm fact: Adult glowworm flies (fungus gnats) never get caught in these sticky webs because they aren’t attracted to the light; plus, they are strong enough to pull away from the threads.
Where can I find glowworms?
The species of glowworm that can be found in New Zealand is called Arachnocampa luminosa. They most commonly live in caves, forests and other sheltered, damp areas. The most popular glowworm caves in New Zealand are in Te Anau and Waitomo. In caves, the bioluminescent glowing can happen during both day and night because the habitat is dark. Caves are an ideal environment for glowworms to thrive because they are dark with no wind and damp enough for prey to be present.
Glowworm fact: There are hundreds of glowworms in the Te Anau caves that collectively glitter like stars to create a magical and unforgettable experience.
This particular species of glowworm can only be found in New Zealand and parts of Australia. Glowworms in other parts of the world actually refer to beetles, making our glowworms unique. Don’t miss this special opportunity to see nature at its best and book a tour to the Te Anau glowworm caves today!