Meet the amazing glowworms of Waitomo caves

The New Zealand glowworm is not a worm but an insect.

It is different from glowworms and fireflies in other parts of the world.

Its name Arachnocampa luminosa might give you the idea that it is a kind of luminous spider.

But that is not true either.

You can meet glowworms at the Waitomo Caves on the North Island of New Zealand.

To journey to the glowworm grotto, you need a boat to take you to see these tiny creatures.

The glowworm cave

The Glowworm Cave is a wonder, beautifully lit to show the magnificent artistry of stalactite and stalagmite formations, which have built up over many thousands of years.

When light are turned on lights you will be amazed at the fascinating formations and tunnels—an unexpected and strange world of marvels under the ground.

When switched off your footsteps will echo eerily when you gather at the top of stairs that descended into blackness.

Just  as your eyes became accustomed to the dark, you will begin to see tiny glimmers of greenish light high up. The glowworms!

It will be like a compressed version of the entire Milky
Way appeared just above you—the roof of the cave completely covered with glowworms.

"Author George Bernard Shaw called this place “the eighth wonder of the world.”

The fascinating glowworm

Starting life as a tiny larva, with tail light already switched on, the New Zealand glowworm builds a hammock of mucus and silk from separate glands in its mouth and attaches it to the ceiling of a grotto.

The hammock is actually a tunnel in which the larva can move back and forth.

The glowworm needs food to live, so for six to nine months, it takes up fishing.

But its catch is in the air, though it comes via the water.

The essential stream brings in a supply of midges, mosquitoes, stone flies, and mayflies, which are attracted to light.

To catch them, the glowworm lets down a series of silken lines (sometimes as many as 70) from its hammock.

Spaced evenly down each line is a series of sticky droplets of mucus, so the lines resemble tiny pearl necklaces hanging straight down.

The most fascinating part of the glowworm is the light with which it illuminates the fishing lines.

The New Zealand glowworm is one of a group of insects whose glow is not connected to the nervous system.

Yet, it is able to turn the light off at will.

The light organ is housed at the end of its excretory tubes, and part of the larva’s breathing system acts as a reflector, sending the light downward.

It turns the light off by restricting the oxygen or the chemicals needed to produce the light.

However, the light at the end of the glowworm tunnel is not the hopeful sign an insect expects.

The glowworm flies into the deadly curtain where a chemical may, it has been suggested, gradually anesthetize it.

Sensing the vibrations of the struggling victim, the larva hangs precariously out of the hammock and hauls up the line in its mouth, using contractions of its body.

Having fished and fed for six to nine months, the larva pupates and then enjoys life as an adult.

Whether the adult fly actually enjoys life much is doubtful.

It will last only two or three days, for the adult fly has no mouth and so cannot eat.

Its remaining time is devoted to reproduction.

Adult male flies fertilize females the moment they break out of their cocoons.

The female may take an entire day to lay her eggs, one by one, after which she dies.

Having contributed to a sparkling galaxy that gives immense pleasure to humans, the 10- to 11-month life cycle of the tiny New Zealand light-bearer is over.