Who would have thought that a creature called a fungus gnat could be such a popular attraction? Fungus gnats are a special kind of fly and there's a species in New Zealand that produces the amazing glow worm. And our Glow Worm Kayaking tours at Lake McLaren are the perfect way to see their stunning light show!
There are many different types of glow worm. The one we have in New Zealand is the arachnocampa luminosa. It uses its glow to attract food and to burn off its waste.
The glow worm lives for about 11 months in a cycle that involves four different stages. The adult lays eggs in clutches of 30-40 within their subterranean home. When the young gnat larvae hatch and crawl away they are less than 3 millimetres long, but already emit a strong visible light. They slowly grow over 9 months to the shape and size of a matchstick, building a tube-like nest and putting down sticky 'fishing lines' to trap insects to feed on.
Snuggled up in their silky tubes, the hungry glow worms emit that ethereal blue-green glow in order to lure prey onto the lines. Trapped on the sticky mucus threads, the unwitting insects are then reeled in for supper.
The tail light shines from an organ similar to the human kidney. The airbag surrounding the tail provides it with oxygen which reacts with the chemicals given off by the glow worm. They are able control the reaction by reducing the level of oxygen to the light organ.
The glow worm then turns into a pupa in a cocoon suspended from the ceiling and emerges as a two winged flying insect, which looks like a large mosquito. The adult fly lives no longer than a few days - its sole purpose is to reproduce and lay eggs - and the cycle continues.
Glow worms need damp dark sheltered places like caves, tunnels or moist banks and canyons where they can safely hang their sticky feeding lines. That's why they do so well at Lake McLaren, transforming their dark surroundings with pinpoints of starry glow worm light.
Seeing the constellations form on the canyon walls while you glide silently through on a kayak is truly an awesome experience. And it becomes easy to appreciate the beautiful Māori word for glow worm – ‘titiwai’, referring to ‘lights reflected in water’.