Glowworm Tour New Zealand

On a Spellbound glowworm tour in New Zealand, you will not only find out more about these fascinating and almost magical little creatures, but you will view them up close in their natural habitat.

Adult glowworm fly beside empty pupa case.

N. Z. Glowworm (Arachnocampa luminosa)

Waitomo has a handful of spectacular glowworm caves. The Spellbound Glowworm cave offers arguably the best glowworm tour in New Zealand for seeing glowworms up close and in great numbers.

New Zealand glowworms live all over New Zealand; they're very common and found in forest settings, usually under overhanging stream banks. Where conditions are suitable they live in caves and can colonise cave ceilings in impressive numbers.

Some unkind people refer to glowworms as glow maggots, and technically they're correct. The "worm" you see on the ceiling of the Spellbound Glowworm Cave is the larval or maggot stage of a fungus gnat fly. The adult fly looks a little like a mosquito, you may see one in the cave but it is so non-descript you mayhardly notice it. Cave life is so good for glowworms they usually complete their entire life cycle within the cave.

Find out for yourself on a New Zealand glowworm tour, just why these little glowworms are so interesting!

Glowworm light is made from a biochemical reaction called bioluminescence which takes place in the renal glands or kidneys of the glowworm. Energy for the light is sourced from the glowworm's own waste products, a very energy efficient strategy. Glowworms produce 'cold' light, a pure light with almost no associated heat, another way of saving energy.

Glowworms can turn off their lights. They may do this when there there is too much bright light from another source, or to 'hide' if disturbed.

Glowworm larva lying in a silk hammock. Sticky silk threads hang from ceiling nearby.

The glowworm larva uses the light at its tail end as an irresistible lure to attract small flying insects lost in the darkness of the cave. Adult females can also produce a light which may help to attract a mate.

To catch food, the glowworm larva builds a network of silk threads that hang down vertically around its 'silk hammock'. As the glowworm produces each line from its silk glands, it places droplets of very sticky mucus over the thread line. Lost insects fly towards the larva's light lure and into a tangle of sticky silk threads and rarely escapes.

The glowworm draws the silk line and the trapped insect upwards and into its mouth, sucks out the juices and spits out the hard parts.

When glowworm larvae hatch from eggs, the first to emerge eat later emerging siblings, this gives them energy to crawl away from the egg cluster and establish their own hammock and feeding lines.

Glowworms are very territorial and can sometimes be seen fighting for space. They may eat one another; sometimes a glowworm is pushed off the ceiling and lands in the stream below.

NZ glowworms are closely related to Australian glowworms which have very similar appearance and behaviour.

A mayfly is caught on a silk thread.

Why is life so good in caves? There are a number of reasons for large colonies occurring in some caves.

• Glowworms thrive in stream caves. The stream transports emerging aquatic insects into the cave, providing a year round food source for glowworms. A healthy unpolluted stream generates lots of food.
• Caves are damp and humid all year round, it's important for glowworm larvae that they do not dry out.
• Cave temperatures are fairly steady and comfortable for glowworms.
• In a cave it's always dark, giving glowworms more time with their lights on to catch food.
• Glowworms survive best in caves which have very little air movement; breezy conditions will tangle the glowworm's fishing lines making it too hard to catch food.

The Spellbound glowworm cave has such ideal conditions for glowworms to grow and multiply, we think of it as a glowworm paradise!

Book your glowworm tour New Zealand:

We look forward to receiving your booking and welcoming you onto your Spellbound glowworm tour - New Zealand's finest glowworm cave experience.