New Zealand kept in secret through the time, several natural treasures. But there is a particular cave system who aroused a special fascination.
The caves, located in the southern Waikato region of the North Island of New Zealand were explored in 1887 by a Maori Chief, Tane tinorau and an Englisg surveyor, Fred Mace. The 300 known limestone caves were formed 30 million years ago by volcanic activity. In this limestone are fossilized corals, and sea shells and fishes. The formations as stalactites and stalagmites grew from water dripping from the ceiling or flowing over the walls and leaving behind limestone deposits.
The name of the caves is Waitomo Glowworm Caves. “Waitomo” comes from the Maori words “wai”, that means “water” and tomo, that menas “hole or shaft”. The most renowned inhabitant of this cave system are not the goblins, so vividly described by JRR Tolkien in his books, there are a tiny but fancies kind of worms. This worms are named Arachnocampa luminosa and are found exclusively in New Zealand.
Another inhabitants are a kind of fungi with a distant filogenetic relation with the genus Pleurotus, a albino cave ants and a giant crickets.
Arachnocampa species go through a life cycle of eggs hatching to luminiscent larvae and then pupating to an adult fly. They spend most of their life as larvae.
The larval stage lasts about 6 to 12 months.
The larva spins a nest out of silk on the ceiling of the cave and then hangs down as many as 70 threads of silk, the snares, from around the nest, each up to 30 or 40 cm long and holding droplets of mucus. The larvae can only live in a place out of the wind, to stop their lines being tangled, hence caves, overhangs or deep rainforest.
The larva glows to attract prey into its threads, perhaps luring them into believing they are outdoors, for the roof of a cave covered with larva can look remarkably like a blue starry sky at night. If prey is scarce the larvae will turn to cannibalism, eating other larvae, pupae or adult flies.
The glow is the result of a chemical reaction that involves luciferin (substrate), luciferase (enzyme that acts upon luciferin), ATP or adenosine triphosphate (energy molecule) and oxygen. It occurs in Malpighian tubules, a modified excretory organs in the abdomen.